Incidence and Prevalence of Acromegaly in the United States: A Claims-Based Analysis

Objective: Acromegaly, a rare endocrine disorder, results from excessive growth hormone secretion, leading to multisystem-associated morbidities. Using 2 large nationwide databases, we estimated the annual incidence and prevalence of acromegaly in the U.S.Methods: We used 2008 to 2013 data from the Truven Health MarketScan® Commercial Claims and Encounters Database and IMS Health PharMetrics healthcare insurance claims databases, with health plan enrollees <65 years of age. Study patients had ≥2 claims with acromegaly (International Classification of Diseases, 9th Revision, Clinical Modification Code [ICD-9CM] 253.0), or 1 claim with acromegaly and 1 claim for pituitary tumor, pituitary surgery, or cranial stereotactic radiosurgery. Annual incidence was calculated for each year from 2009 to 2013, and prevalence in 2013. Estimates were stratified by age and sex.Results: Incidence was up to 11.7 cases per million person-years (PMPY) in MarketScan and 9.6 cases PMPY in PharMetrics. Rates were similar by sex but typically lowest in ≤17 year olds and higher in >24 year olds. The prevalence estimates were 87.8 and 71.0 per million per year in MarketScan and PharMetrics, respectively. Prevalence consistently increased with age but was similar by sex in each database.Conclusion: The current U.S. incidence of acromegaly may be up to 4 times higher and prevalence may be up to 50% higher than previously reported in European studies. Our findings correspond with the estimates reported by a recent U.S. study that used a single managed care database, supporting the robustness of these estimates in this population. Our study indicates there are approximately 3,000 new cases of acromegaly per year, with a prevalence of about 25,000 acromegaly patients in the U.S.Abbreviations:CT = computed tomographyGH = growth hormoneIGF-1 = insulin-like growth factor 1ICD-9-CM Code = International Classification of Diseases, 9th Revision, Clinical Modification CodesMRI = magnetic resonance imagingPMPY = per million person-years     

Limitations of Current Approaches For The Treatment of Acromegaly

Objective: Acromegaly is a rare disease characterized by hypersecretion of growth hormone (GH), typically from a benign pituitary somatotroph adenoma, that leads to subsequent hypersecretion of insulin-like growth factor 1 (IGF-1). Patients with acromegaly have an increased risk of mortality and progressive worsening of comorbidities. Surgery, medical therapy, and radiotherapy are currently available treatment approaches for patients with acromegaly, with overall therapeutic goals of lowering GH levels and achieving normal IGF-1 levels, reducing tumor size, improving comorbidities, and minimizing mortality risk. Although surgery can lead to biochemical remission in some patients with acromegaly, many patients will continue to have uncontrolled disease and require additional treatment.Methods: We reviewed recently published reports and present a summary of the safety and efficacy of current treatment modalities for patients with acromegaly.Results: A substantial proportion of patients who receive medical therapy or radiotherapy will have persistently elevated GH and/or IGF-1. Because of the serious health consequences of continued elevation of GH and IGF-1, there is a need to improve therapeutic approaches to optimize biochemical control, particularly in high-need patient populations for whom current treatment options provide limited benefit.Conclusion: This review discusses current treatment options for patients with acromegaly, limitations associated with each treatment approach, and areas within the current treatment algorithm, as well as patient populations for which improved therapeutic options are needed. Novel agents in development were also highlighted, which have the potential to improve management of patients with uncontrolled or persistent acromegaly.Abbreviations:AACE = American Association of Clinical EndocrinologistsAE = adverse eventATG = AutogelCFRT = conventional fractionated radiotherapyDA = dopamine agonistENDO = Endocrine SocietyGH = growth hormoneGHRA = growth hormone receptor antagonistIGF-1 = insulin-like growth factor 1LAR = long-acting releaseLFT = liver function testSC = subcutaneousSRS = stereotactic radiosurgerySSA = somatostatin analoguesst = somatostatin receptorsst₂ = somatostatin receptor subtype 2sst₅ = somatostatin receptor subtype 5TSS = transsphenoidal surgery     

Discordance Between Gh and Igf-1 Levels in Turkish Acromegalic Patients

Objective: Discordance between insulin-like growth factor-1 (IGF-1) and growth hormone (GH) levels is an important problem in the follow-up of patients diagnosed with acromegaly. Our aims were to evaluate the discordance between IGF-1 and GH levels and compare the performance of different cut-off levels for the nadir in GH (GHn) in acromegalic patients.Methods: The study included 63 acromegalic patients in a follow-up at a tertiary care university hospital facility. Levels of IGF-1, IGF binding protein-3 (IGFBP-3), and GH were investigated. The baseline GH and GHn levels were evaluated after an oral glucose tolerance test (cut-offs of 0.4 and 1 ng/mL, respectively). The discordance rates between GHn and IGF-1 levels, and IGF-1/IGFBP-3 ratios were determined.Results: We first adopted a GHn cut-off value of 1 ng/mL and found that 27 patients (42.9%) exhibited biochemical remission (BR) (IGF-1 <95^th percentile, GH <1), and 25 patients (39.7%) had no BR (NBR) (IGF-1 ≥95^th percentile, GH >1).Discordance in the presence of normal IGF-1 and nonsuppressed GH (DC1) occurred in 2 of 63 (3.2%) patients; discordance in the presence of high IGF-1 and suppressed GH (DC2) occurred in 9 of 63 (14.3%) patients. If the GHn cut-off value adopted was 0.4 ng/mL, the distributions were 17 of 63 (27.0%) patients in BR, 29 of 63 (46.0%) patients in NBR, 12 of 63 (19.0%) in DC1, and 5 of 63 (7.9%) patients in DC2. If only the baseline GH values were considered, the distributions were very similar to those with a GHn cut-off value of 0.4 ng/mL. The IGF-1/IGFBP-3 ratio was lowest in the BR group.Conclusion: Adopting a GHn cut-off value of 0.4 ng/mL did not increase the test performance compared with baseline GH only. In contrast, in the follow-up of acromegalic patients, the IGF-1/IGFBP-3 ratio might be a useful measurement when discordance between IGF-1 and GH levels occurs. We propose that these values be considered in clinical practice.Abbreviations:BR = biochemical remissionDC1 = discordance group 1DC2 = discordance group 2DM = diabetes mellitusGH = growth hormoneGHn = nadir in GHIGF-1 = insulin-like growth factor-1IGFBP-3 = IGF binding protein-3LAR = long-acting releaseNBR = not in biochemical remissionOGTT = oral glucose tolerance test     

Decrease in Acromegaly-Associated Thyroid Enlargement after Normalization of IGF-1 Levels: A Prospective Observation and in Vitro Study

Objective: Goiter occurs at high frequency in acromegaly patients. Whether normalization of insulin-like growth factor 1 (IGF-1) levels could decrease goiter and thyroid volume remains unclear.Methods: Thyroid hormone levels and ultrasound measurements were assessed in 101 acromegaly patients, compared with 108 patients with nonfunctioning pituitary adenoma (NFPA) and 55 healthy controls. Thirty-four acromegaly patients underwent repeat evaluation 1 year post–transsphenoidal surgery. The effect of IGF-1 on thyroid cell proliferation, cell cycle, and apoptosis was evaluated in vitro.Results: Acromegaly patients showed larger thyroid volume than those with NFPAs (18.32 mL vs. 9.91 mL; P<.001) and healthy controls (18.32 mL vs. 9.63 mL; P<.001). Duration of acromegaly was shown to be independently associated with thyroid volume enlargement (B = 0.259; 95% confidence interval, 0.162 to 0.357) in multivariate analysis. At follow-up, the median thyroid volume decreased from 22.74 to 17.87 mL in the cured group (n = 20; P = .003), but the number of nodular goiters showed no significant change. Serum free thyroxine levels decreased from 13.76 to 10.08 pmol/L in the cured group (P = .006) but increased from 9.28 to 12.09 pmol/L in the active group (P = .013). Change in thyroid volume was significantly correlated with IGF-1 level (r = 0.37; P = .029). In vitro, IGF-1 time- and dose-dependently promoted proliferation and secretory function of thyroid cells by enhancing cell cycle shift from the G1/S to G2/M phase and suppressing apoptosis.Conclusion: Acromegaly-associated thyroid volume increase, but not nodular goiter, could be reversed in cured acromegaly. IGF-1 time- and dose-dependently promoted the proliferation and secretory function of thyroid cells.Abbreviations: CCK-8 = Cell Counting Kit-8; fT3 = free triiodothyronine; fT4 = free thyroxine; GH = growth hormone; IGF-1 = insulin-like growth factor 1; MRI = magnetic resonance imaging; NFPA = nonfunctioning pituitary adenoma; qRT-PCR = quantitative real-time–polymerase chain reaction; TSH = thyroid-stimulating hormone     

Comparison of Cabergoline Versus Raloxifene Add-On Therapy to Long-Acting Somatostatin Analogue in Patients With Inadequately Controlled Acromegaly: A Randomized Open Label Clinical Trial

Objective: The present study aimed to evaluate the efficacy of add-on therapy of cabergoline versus raloxifene to long-acting somatostatin analogues (SAs) in patients with inadequately controlled acromegaly.Methods: This was a prospective, randomized open label clinical trial. Forty-four patients (22 per group) completed the study; where participants received either cabergoline (3 mg/week) or raloxifene (60 mg twice daily) add-on therapy for 12 weeks in a parallel manner. The primary outcome was the rate of reduction in serum insulin-like growth factor 1 (IGF-1) from baseline. Secondary outcomes comprised normalization of serum IGF-1 for age and sex.Results: Serum IGF-1 was significantly decreased in both the cabergoline (40.3 ± 25.6%, P<.001) and raloxifene (31.5 ± 24.6%, P<.001) groups, with no significant difference between arms (P>.05). Normalization in serum IGF-1 values occurred in 40.9% of patients who were on cabergoline compared to 45.5% of those receiving raloxifene (P = .76). The subsequent logistic regression analysis highlighted baseline IGF-1 as a significant predictor of IGF-1 normalization (odds ratio, 0.995; 95% confidence interval, 0.990–0.999; P = .02). Using the receiver operating characteristic (ROC) curve analysis for the entire group, the baseline IGF-1 value of 1.47 the upper limit of normal (ULN) was the best cut-off point to identify patients with normal IGF-1 at the end of the study (sensitivity: 52.6%, specificity: 84.0%, Yoden's index: 0.366). Full biochemical control of acromegaly was achieved in 22.7% of patients in the cabergoline group compared to 13.6% of those in the raloxifene group (P = .43).Conclusion: Cabergoline and raloxifene add-on therapy could effectively decrease serum IGF-1 level in patients with inadequately controlled acromegaly. The efficacy profiles of both drugs are comparable.Abbreviations: DA = dopamine agonist; FBG = fasting blood glucose; GH = growth hormone; IGF1 = insulin-like growth factor-1; IQR = interquartile range; OR = odds ratio; ROC = receiver operating characteristic; SA = somatostatin analogue; SERM = selective estrogen modulator receptor; ULN = upper limit of normal     

No Benefit of Dedicated Thyroid Nodule Screening in Patients with Acromegaly

Objective: Acromegaly results from the excessive production of growth hormone and insulin-like growth factor-1. While there is up to a 2-fold increased prevalence of thyroid nodules in patients with acromegaly, the incidence of thyroid cancer in this population varies from 1.6 to 10.6% in several European studies. The goal of our study was to determine the prevalence of thyroid nodules and thyroid cancer among patients with acromegaly at a large urban academic medical center in the United States (U.S.).Methods: A retrospective chart review was performed of all patients with acromegaly between 2006–2015 within the University of California, Los Angeles health system. Data were collected regarding patient demographics, thyroid ultrasounds, thyroid nodule fine needle aspiration (FNA) biopsy cytology, and thyroid surgical pathology.Results: In this cohort (n = 221, 49.3% women, mean age 53.8 ± 15.2 &lsqb;SD] years, 55.2% Caucasian), 102 patients (46.2%) underwent a thyroid ultrasound, from which 71 patients (52.1% women, mean age 52.9 ± 15.2 &lsqb;SD] years, 56.3% Caucasian) were found to have a thyroid nodule. Seventeen patients underwent a thyroid nodule FNA biopsy and the results revealed 12 benign biopsies, 1 follicular neoplasm, 3 suspicious for malignancy, and 1 papillary thyroid cancer (PTC), from which 6 underwent thyroidectomy; PTC was confirmed by surgical pathology for all cases (8.5% of all nodules observed).Conclusion: In this sample, the prevalence of thyroid cancer in patients with acromegaly and coexisting thyroid nodules is similar to that reported in the general U.S. population with thyroid nodules (7 to 15%). These findings suggest that there is no benefit of dedicated thyroid nodule screening in patients newly diagnosed with acromegaly.Abbreviations: AACE = American Association of Clinical Endocrinologists; ATA = American Thyroid Association; DTC = differentiated thyroid cancer; FNA = fine needle aspiration; GH = growth hormone; IGF-1 = insulin-like growth factor-1; PTC = papillary thyroid cancer; U.S. = United States     

Necessity of Multimodal Treatment of Acromegaly and Outcomes

Objective: Uncontrolled acromegaly is associated with increased morbidity and mortality. Despite multimodal therapeutic options, adequate control can be challenging and lead to prolonged exposure to growth hormone excess. The aim of this study was to assess treatment patterns and outcomes in patients with acromegaly following surgery at a single institution.Methods: A retrospective analysis of response to treatment modalities for patients with a new diagnosis of acromegaly at the Mayo Clinic in Rochester, Minnesota, from 1995–2015.Results: A total of 245 patients with newly diagnosed acromegaly (mean age at diagnosis, 47 ± 14 years; mean follow-up, 5.5 ± 5 years) were evaluated. Primary surgical intervention was performed in 236 patients; 117 (54%) did not achieve remission. Among those with ≥3 months follow-up, 76/217 (35%) patients required three or more forms of treatment. Mean tumor size at diagnosis was 1.6 ± 0.8 cm (80% macroadenomas), and 35% (75/217) had cavernous sinus invasion on pre-operative imaging. The most common second-line treatment was radiation treatment (RT) (50%, 59/117). Among those with persistent disease following surgery, a normal insulin-like growth factor 1 (IGF-1) was achieved in 52% (61/117), with a median time to acromegaly control of 4.5 years. The rate of IGF-1 normalization was 2.1-fold higher in those who received RT compared to those who did not.Conclusion: In patients with persistent acromegaly following surgery, multiple treatment modalities, including RT, may be required to achieve remission. Treatment outcome uncertainty and the need for multiple interventions add to the disease burden associated with persistent acromegaly.Abbreviations: CI = confidence interval; GH = growth hormone; IGF-1 = insulin like growth factor-1; KM = Kaplan-Meier; RT = radiation treatment     

Comparative Efficacy of Medical Treatment for Acromegaly: A Systematic Review and Network Meta-Analysis of Integrated Randomized Trials and Observational Studies

Objective: Comprehensive evidence comparing different medications for acromegaly is scarce. The aim of this study was to perform a network meta-analysis based on evidence from both randomized trials and observational studies of medical treatments for acromegaly.Methods: Electronic databases were searched for both observational studies and randomized trials that enrolled acromegaly patients treated with medications of interest. Simulated trials were generated by a machine learning algorithm and then synthesized with Bayesian random-effects network meta-analyses. The main outcome was the rate of insulin-like growth factor 1 (IGF-1) control after medical treatment.Results: We included 90 studies (100 arms, 4,523 patients) before matching. After matching, 28 simulated trials were generated. Balance of matched arms was checked by spatial distance and correlation matrix. Cotreatment with somatostatin receptor ligands and pegvisomant was the most effective treatment compared with other treatments. In unselected patients, pegvisomant was better than octreotide long-acting release (logOR, 0.85; 95% credible interval [CrI], 0.05 to 1.65) or lanreotide (logOR, 1.09, 95% CrI, 0.05 to 2.14), and the mean absolute IGF-1 control rate ranged from 40 to 60%. In partially responsive patients, cotreatment with somatostatin receptor ligands and pegvisomant was similar to pegvisomant monotherapy, ranking as the most two effective treatments, and the mean absolute IGF-1 control rate was over 60%.Conclusion: Our analysis suggested that the combination of data from observational studies and randomized trials in network meta-analysis was feasible. The findings of this network meta-analysis provided robust evidence supporting the current guidelines in treatment strategy for acromegaly.Abbreviations: CrI = credible interval; DA = dopamine agonist; GH = growth hormone; IGF-1 = insulin-like growth factor 1; ITT = intention-to-treat; LAN = lanreotide; LAN-ATG = lanreotide autogel; OCT = octreotide; OCT-LAR = octreotide long acting repeatable; OR = odds ratio; PEG = pegvisomant; PP = per-protocol; SRL = somatostatin receptor ligand     

American Association of Clinical Endocrinologists and American College of Endocrinology Disease State Clinical Review: Management of Acromegaly Patients: What is the Role of Pre-Operative Medical Therapy?

Objective: Acromegaly is a complex disease characterized by growth hormone (GH) excess originating in most cases from a pituitary tumor. The goals of treatment include removing the tumor or reducing tumor burden, normalizing GH secretion and insulin-like growth factor 1 levels, and preserving normal pituitary function if possible. Surgery by an experienced neurosurgeon is still considered first-line therapy, especially in cases with small tumors. In the last few decades, significant progress in the development of selective pharmacologic agents has greatly facilitated the management of active acromegaly, with agents such as somatostatin-receptor ligands (SRLs), GH-receptor antagonists, and dopamine agonists. In addition to adjuvant treatment, pre-operative medical therapy and primary therapy in de novo patients are increasingly employed.Methods: A United States National Library of Medicine PubMed search (through July 2014) was conducted for the following terms: acromegaly, pre-operative medical therapy, somatostatin-receptor ligands, and somatostatin analogs. Articles not in English and those not in peer-reviewed journals were excluded. In reviewing pertinent articles, focus was placed on biochemical and other postoperative outcomes of medical therapy.Results: An analysis of the full effect of pre-operative use of SRLs on surgical outcomes (remission rates and peri-operative complications) is limited by heterogeneity of methodology, low overall surgical cure rates, and different study designs. The assumption that SRL use prior to surgery reduces peri-operative surgical risk has yet to be proven. A variable degree of tumor shrinkage with preoperative SRLs is observed. Likewise, SRL treatment 3 months before surgery may improve surgical remission rates in the short term; however, positive results do not persist in the long term.Conclusion: We consider that medical therapy before surgery could play a role in carefully selected patients, but treatment should be individualized. Primary medical therapy with a SRL may be considered in patients with macroadenomas without local mass effects on the optic chiasm, as SRLs have been shown to reduce tumor size and control GH hypersecretion. However, the data are insufficient to support general use of a SRL prior to surgery in order to improve post-surgery biochemical outcomes. Theoretically, patients with severe cardiac and respiratory complications due to acromegaly could potentially benefit from pre-operative SRLs in order to reduce peri-operative morbidity. Further investigation and investment in large randomized long-term clinical trials are needed to define the precise role and duration of pre-surgical medical treatment in acromegaly patients.Abbreviations: GH = growth hormone IGF-1 = insulin-like growth factor 1 MRI = magnetic resonance imaging SRL = somatostatin-receptor ligand     

Medical Treatment Landscape for Active Acromegaly in A Pituitary Center in Israel

Objective: To evaluate current real-life experience with medical treatment for active acromegaly in a large cohort.Methods: Data on demographic parameters, blood tests, imaging studies, and treatments were extracted from the medical records.Results: The cohort included 87 patients (43 male) with active acromegaly. The mean age at diagnosis was 40.2 ± 11.4 years, and the mean duration of follow-up was 7.9 ± 5.8 years. Seventy patients presented with a macroadenoma. Mean baseline insulin growth factor 1 (IGF-1) (n = 67) was 3.2 ± 1.9 × upper limit of normal (ULN). Surgery and radiotherapy were performed in 75 and 10 patients, respectively. Currently, 38 subjects receive somatostatin analogues, pegvisomant as a monotherapy is given to 8 patients, pasireotide is given to 17 patients, cabegoline to 4 patients, estrogen to 2 females, and SSAs combined with pegvisomant to 10 patients. Eight patients are not being actively treated, including 4 following radiotherapy. Good biochemical control (IGF-1 <1.3 × ULN) was achieved in 76 patients (87%), and 11 patients (13%) are currently uncontrolled (IGF-1 >1.3 × ULN). Seventy-eight percent of controlled patients are being given 1 medication; 11% are on combination therapy; 4 patients are well controlled after radiotherapy and 2 are partially controlled without any treatment. The main adverse effects of treatment were diabetes mellitus in 7 patients (on pasireotide) and symptomatic cholelithiasis in 5 patients.Conclusion: Active acromegaly can be controlled medically in most patients, with a low rate of adverse effects. This study displays the characteristic variety of treatment options available for active acromegaly.     

Tumorigenesis of Papillary Thyroid Cancer Is Not BRAF-Dependent in Patients with Acromegaly

Introduction

Several studies have reported a high frequency of papillary thyroid cancer (PTC) in patients with acromegaly. The aim of this study was to determine the prevalence and predictors of thyroid cancer in patients with acromegaly and to investigate the frequency of the BRAF ^V600E mutation in PTC patients with and without acromegaly.

Materials and Methods

We conducted a retrospective study of 60 patients with acromegaly. Thyroid ultrasonography (US) and US-guided fine needle aspiration were performed on nodules with sonographic features of malignancy. We selected 16 patients with non-acromegalic PTC as a control group. The BRAF ^V600E mutation was analyzed in paraffin-embedded surgical specimens of PTC by real-time polymerase chain reaction, and tumor specimens from patients with PTC were stained immunohistochemically with an antibody against insulin-like growth factor-1 receptor β (IGF-1Rβ).

Results

Thyroid cancer was found in 15 (25.0%) patients. No differences in age, sex, initial growth hormone (GH) and IGF-1 percentage of the upper limit of normal values or treatment modalities were observed between patients with and without PTC. Acromegaly was active in 12 of 15 patients at the time of PTC diagnosis; uncontrolled acromegaly had a significantly higher frequency in the PTC group (60%) than in the non-PTC group (28.9%) (p = 0.030). The BRAF ^V600E mutation was present in only 9.1% (1/11) of PTC patients with acromegaly, although 62.5% (10/16) of control patients with PTC had the mutation (p = 0.007). IGF-1Rβ immunostaining showed moderate-to-strong staining in all malignant PTC cells in patients with and without acromegaly. Significantly less staining for IGF-1Rβ was observed in normal adjacent thyroid tissues of PTC patients with acromegaly compared with those without (p = 0.014).

Conclusion

The prevalence of PTC in acromegalic patients was high (25%). An uncontrolled hyperactive GH-IGF-1 axis may play a dominant role in the development of PTC rather than the BRAF ^V600E mutation in patients with acromegaly.     

Trabecular Bone Score Change Differs with Regard to 25(OH)D Levels in Patients Treated for Adult-Onset Growth Hormone Deficiency

Objective: Vitamin D is important in bone health. However, potential relationships of concomitant vitamin D deficiency with growth hormone deficiency (GHD) and the possibility that vitamin D inadequacy may alter the skeletal effects of growth hormone (GH) replacement therapy have not been adequately evaluated.Methods: A prospective study was conducted in adult-onset GHD patients treated with recombinant human GH (rhGH) for 2 years. Trabecular bone score (TBS), lumbar spine (LS) bone mineral density (BMD), total hip (TH) BMD, and 25-hydroxyvitamin D (25(OH)D) levels were assessed at baseline and 24 months. The study cohort was divided based on 25(OH)D levels into 2 groups with the cutoff defined as the 50^th percentile at each follow-up time point.Results: Fifty-seven patients (29 males/28 females, mean age 34.4 years) were studied. After 24 months of GH replacement, LS BMD increased by 7.6% and TH BMD increased by 4.5% (both P<.05), with no difference according to 25(OH)D levels. TBS increased (+1.39 ± 3.6%) in those whose 25(OH)D was above the 50^th percentile but decreased (-1.36 ± 5.6%, P<.05) in the cohort below the 50^th percentile of 25(OH)D. Positive correlations were observed between baseline levels of IGF-1 and 25(OH)D (R = 0.37, P<.001) and between 24-month 25(OH)D and TBS (R = 0.25, P<.05).Conclusion: A differential effect of GH on TBS change was observed; TBS increased only in the cohort with 25(OH)D above the 50^th percentile. Vitamin D sufficiency may be required to obtain optimal effects of GH treatment on bone quality, as assessed by TBS, in GHD adults.Abbreviations:AO-GHD = adult-onset GHDBMD = bone mineral densityBMI = body mass indexCa = calciumCTx = carboxyterminal collagen crosslinksCV = coefficient of variationDXA = dual energy X-ray absorptiometryECLIA = enzyme-labeled chemiluminescent immunometric assayGH = growth hormoneGHD = growth hormone deficiencyIGF-1 = insulin-like growth factor 1LS BMD = lumbar spine BMDOC = osteocalcin25(OH)D = 25-hydroxyvitamin DP = phosphorusPTH = parathyroid hormonerhGH = recombinant human GHTBS = trabecular bone scoreTH BMD = total hip BMD     

Historical Response Rates Of Somatostatin Analogues In The Treatment Of Acromegaly: A Systematic Review

Objective: In a completed phase III study (C2305, Clinicaltrials.gov identifier: NCT00600886), the reported rate of biochemical control with octreotide long-acting release (LAR) was lower than rates historically reported in patients pretreated and/or selected for response with somatostatin analogue (SSA) therapy. To assess whether lower efficacy rates of octreotide LAR in C2305 were influenced by study design, a systematic review of the literature was performed to evaluate response rates in previously published studies in acromegaly with similar design characteristics.Methods: PubMed was used to search for English-language clinical studies of acromegaly published through May 2014. Prospective studies of medically naïve patients (≥20) treated with SSAs for ≤12 months that reported efficacy rates using composite endpoint measures (growth hormone [GH] and insulin-like growth factor 1 [IGF-1]) were included. Two separate authors independently screened abstracts and full-length articles of each study to determine eligibility. All authors met to review and reach consensus when primary reviewers disagreed on the inclusion or exclusion of specific studies.Results: A total of 9 studies (N = 354 patients) were identified, with reported mean efficacy rates of 31% (range, 20–54%). Of note, reported mean efficacy rates were lower in studies enrolling patients naïve to any form of treatment (surgery, medical, and/or radiation) than in studies that enrolled only medically naïve patients. A limitation of this analysis was that inclusion criteria restricted the number of studies analyzed.Conclusion: Interpretation of biochemical response rates with SSAs is critically dependent on the context of the study and should be evaluated across clinical trials with similar study design characteristics.Abbreviations:ATG = AutogelGH = growth hormoneIGF-1 = insulin-like growth factor 1LAR = long-acting releaseOGTT = oral glucose tolerance testSSA = somatostatin analogue     

The Prevalence of Cancer and Its Relation to Disease Activity in Patients With Acromegaly: Two Centers' Experience

ObjectiveAcromegaly is characterized by increased serum concentrations of growth hormone (GH) and insulin-like growth factor 1 (IGF-1). Although animal studies have demonstrated a relationship between these hormones and cancer risk, the results of human studies evaluating cancer prevalence in acromegaly are inconsistent. We aimed to investigate the prevalence of malignant neoplasms in patients with acromegaly.MethodsCancer risk was evaluated in a cohort of 280 patients (male/female: 120/160; mean age: 50.93 ± 12.07 years) with acromegaly. Patients were categorized into 2 groups according to the presence or absence of cancer. Standard incidence ratios were calculated as compared to the general population.ResultsFrom 280 patients, cancer was diagnosed in 19 (6.8%) patients; 9 (47%) of them had thyroid cancer, which was the most common cancer type. Standard incidence ratios of all cancers were 0.8 (95% CI, 0.5-1.1) and 1.0 (95% CI, 0.8-1.3) in men and women, respectively. Compared to patients without cancer, the current age was higher in patients with cancer (59 [49-65] to 51 [42-59], P = .027). In contrast, the age at diagnosis was similar in both groups. Not only was the time to diagnosis and disease duration similar in both groups but also the basal and current GH and IGF-1 levels. The prevalence of active disease was also similar between the groups (32% to 23%, P = .394).ConclusionOur findings were not consistent with the studies suggesting that patients with acromegaly encounter an increased cancer risk. Furthermore, there were similar basal and current GH and IGF-1 levels in patients with acromegaly, both with and without cancer.     

Reduced Impact of Diabetes Clinic Referral on High-Frequency Emergency Department Users

Objective: The patterns of emergency department (ED) visits in patients with diabetes are not well understood. The Emergency Department Diabetes Rapid-referral Program (EDRP) allows direct booking of ED patients presenting with urgent diabetes needs into a diabetes specialty clinic within 1 day of ED discharge. The objective of this secondary analysis was to examine characteristics of patients with diabetes who have frequent ED visits and determine reasons for revisits.Methods: A single-center analysis was conducted comparing patients referred to the EDRP (n = 420) to historical unexposed controls (n = 791). The primary outcome was the proportion of patients in each frequency group of ED revisits (none, 1 to 3 [infrequent], 4 to 10 [frequent], or >10 [superfrequent]) in the year after the ED index visit. Secondary outcomes were hospitalization rates and International Classification of Diseases–Ninth Revision (ICD-9) diagnoses at ED revisits.Results: Superfrequent users, responsible for >20% of total ED visits, made up small but not significantly different proportions of EDRP and control populations, 3.6% and 5.2%, respectively. Superfrequent groups had lower hospital admission rates at ED revisits compared to frequent groups. Mental health disorders (including substance abuse) were the primary, secondary, or tertiary ICD-9 codes in 30.6% (95% confidence interval [CI], 27.7% to 33.5%) and 6.6% (95% CI, 5.1% to 8.2%) in the superfrequent and infrequent groups, respectively.Conclusion: Direct access to diabetes specialty care from the ED is effective in reducing ED recidivism but not amongst a small subgroup of superfrequent ED users. This group was more likely to have mental health disorders recorded at ED revisits, suggesting that more comprehensive approaches are needed for this population.Abbreviations: EDRP = Emergency Department Diabetes Rapid-referral Program; ED = emergency department; HbA1c = hemoglobin A1c; ICD-9 = International Classification of Diseases–Ninth Revision     

Predictive Markers for Postsurgical Medical Management of Acromegaly: A Systematic Review and Consensus Treatment Guideline

Objective: To clarify the selection of medical therapy following transsphenoidal surgery in patients with acromegaly, based on growth hormone (GH)/insulin-like growth factor 1 (IGF-1) response and glucometabolic control.Methods: We carried out a systematic literature review on three of the best studied and most practical predictive markers of the response to somatostatin analogues (SSAs): somatostatin receptor (SSTR) expression, tumor morphologic classification, and T2-weighted magnetic resonance imaging (MRI) signal intensity. Additional analyses focused on glucose metabolism in treated patients.Results: The literature survey confirmed significant associations of all three factors with SSA responsiveness. SSTR expression appears necessary for the SSA response; however, it is not sufficient, as approximately half of SSTR2-positive tumors failed to respond clinically to first-generation SSAs. MRI findings (T2-hypo-intensity) and a densely granulated phenotype also correlate with SSA efficacy, and are advantageous as predictive markers relative to SSTR expression alone. Glucometabolic control declines with SSA monotherapy, whereas GH receptor antagonist (GHRA) monotherapy may restore normoglycemia.Conclusion: We propose a decision tree to guide selection among SSAs, dopamine agonists (DAs), and GHRA for medical treatment of acromegaly in the postsurgical setting. This decision tree employs three validated predictive markers and other clinical considerations, to determine whether SSAs are appropriate first-line medical therapy in the postsurgical setting. DA treatment is favored in patients with modest IGF-1 elevation. GHRA treatment should be considered for patients with T2-hyperintense tumors with a sparsely granulated phenotype and/or low SSTR2 staining, and may also be favored for individuals with diabetes. Prospective analyses are required to test the utility of this therapeutic paradigm.Abbreviations: DA = dopamine agonist; DG = densely granulated; GH = growth hormone; GHRA = growth hormone receptor antagonist; HbA1c = glycated hemoglobin; IGF-1 = insulin-like growth factor-1; MRI = magnetic resonance imaging; SG = sparsely granulated; SSA = somatostatin analogue; SSTR = somatostatin receptor     

Significant Elevation of Growth Hormone Level Impacts Surgical Outcomes in Acromegaly

Objective: Transsphenoidal adenomectomy (TSA) is first-line treatment for acromegaly. Our aim was to determine the impact of pre-operative biochemical parameters on the outcomes of surgery.Methods: Retrospective case series of 79 consecutive acromegalics operated between 1994 and 2013. Inclusion criteria were: first TSA, pathology-confirmed growth hormone (GH) adenoma, and follow-up >3 months. Biochemical remission was defined as normal insulin-like growth factor 1 (IGF-1) without adjuvant therapy during follow-up.Results: Median follow-up was 35.4 months (range, 3 to 187 months). Logistic regression analysis showed that the best model to predict long-term remission included the following pre-operative markers: GH, tumor diameter, and cavernous sinus invasion (CSI) (area under the curve, 0.933). A threshold GH of 40 ng/mL was associated with long-term remission (sensitivity, 97%; specificity, 42%). Group A (GH >40 ng/mL) comprised 19 patients (9 men); age, 43 ± 13 years; tumor diameter, 2.7 ± 1.0 cm; 73.7% with CSI; and pre-operative median GH, 77.8 ng/mL (interquartile range [IQR], 66.7 to 107.0 ng/mL). Three patients (15%) in group A achieved remission at 3 months, but 2 patients recurred during follow-up. Group B (GH ≤40 ng/mL) comprised 60 patients (25 men); age, 47 ± 13 years; tumor diameter, 1.6 ± 1.0 cm; 35% with CSI, preoperative median GH, 6.9 ng/mL (IQR, 3.4 to 16.9 ng/mL). Thirty-five patients (58%) in group B achieved remission at 3 months without recurrence during follow-up. Group A had larger tumors and a higher proportion of tumors with CSI (P<.05).Conclusion: Both GH and IGF-1 should be measured pre-operatively, as highly elevated GH levels negatively impact long-term surgical remission. This strategy allows early identification of patients who require adjuvant therapy and may decrease time to biochemical control.Abbreviations: AUC = area under the curve CSI = cavernous sinus invasion GH = growth hormone ICA = internal carotid artery IGF-1 = insulin-like growth factor 1 MRI = magnetic resonance imaging OGTT = oral glucose tolerance test POD2 = postoperative day 2 TSA = transsphenoidal adenomectomy     

Hba1C Control And Cost-Effectiveness in Patients With Type 2 Diabetes Mellitus Initiated On Canagliflozin or A Glucagon-Like Peptide 1 Receptor Agonist in A Real-World Setting

Objective: To compare glycated hemoglobin (HbA1c) control and medication costs between patients with type 2 diabetes mellitus (T2DM) treated with canagliflozin 300 mg (CANA) or a glucagon-like peptide 1 receptor agonist (GLP-1 RA) in a real-world setting.Methods: Adults with T2DM newly initiated on CANA or a GLP-1 RA (index date) were identified from IQVIA™ Real-World Data Electronic Medical Records U.S. database (March 29, 2012–April 30, 2016). Inverse probability of treatment weighting accounted for differences in baseline characteristics. HbA1c levels at 3-month intervals were compared using generalized estimating equations. Medication costs used wholesale acquisition costs.Results: For both cohorts (CANA: n = 11,435; GLP-1 RA: n = 11,582), HbA1c levels decreased at 3 months postindex and remained lower through 30 months. Absolute changes in mean HbA1c from index to 3 months postindex for CANA and GLP-1 RA were -1.16% and -1.21% (patients with baseline HbA1c ≥7% &lsqb;53 mmol/mol]); -1.54% and -1.51% (patients with baseline HbA1c ≥8% &lsqb;64 mmol/mol]); and -2.13% and -1.99% (patients with baseline HbA1c ≥9% &lsqb;75 mmol/mol]), respectively. Postindex, CANA patients with baseline HbA1c ≥7% had similar HbA1c levels at each interval versus GLP-1 RA patients, except 9 months (mean HbA1c, 7.75% &lsqb;61 mmol/mol] vs. 7.86% &lsqb;62 mmol/mol]; P = .0305). CANA patients with baseline HbA1c ≥8% and ≥9% had consistently lower HbA1c numerically versus GLP-1 RA patients and statistically lower HbA1c at 9 (baseline HbA1c ≥8% or ≥9%), 27, and 30 months (baseline HbA1c ≥9%). Continuous 12-month medication cost $3,326 less for CANA versus GLP-1 RA.Conclusion: This retrospective study demonstrated a similar evolution of HbA1c levels among CANA and GLP-1 RA patients in a real-world setting. Lower medication costs suggest CANA is economically dominant over GLP-1 RA (similar effectiveness, lower cost).Abbreviations:AHA = antihyperglycemic agentBMI = body mass indexCANA = canagliflozin 300 mgDCSI = diabetes complications severity indexeGFR = estimated glomerular filtration rateEMR = electronic medical recordGLP-1 RA = glucagon-like peptide 1 receptor agonistHbA1c = glycated hemoglobinICD-9-CM = International Classification of Diseases–Ninth Revision–Clinical ModificationICD-10-CM = International Classification of Diseases–Tenth Revision–Clinical ModificationIPTW = inverse probability of treatment weightingITT = intent-to-treatMPR = medication possession ratioPDC = proportion of days coveredPS = propensity scorePSM = propensity score matchingQuan-CCI = Quan-Charlson comorbidity indexSGLT2 = sodium-glucose cotransporter 2T2DM = type 2 diabetes mellitusWAC = wholesale acquisition cost     

Higher Growth Hormone Levels are Associated with Erectile Dysfunction in Male Patients With Acromegaly

Objective: To investigate in vivo correlates of erectile dysfunction (ED) in male patients with acromegaly.Methods: Fifty-one male patients with acromegaly were assessed by the International Index of Erectile Function-5 and Acromegaly Quality of Life (Acro-QoL) questionnaires. The measurement of serum nitric oxide (NO) were performed in patients and age-matched nonacromegalic controls.Results: Among 51 patients analyzed, 32 (62.7%) had ED. Patients with ED showed lower Acro-QoL scores regarding global (69.8 ± 17.7 versus 79.4 ± 11.2; P = .035) and personal relationship dimensions (59.6 ± 22.1 versus 76.8 ± 17.6; P = .012) than non-ED patients. ED patients were older (44.5 ± 11.2 years versus 33.2 ± 8.5 years; P = .04) and showed higher growth hormone (GH) levels (15.5 μg/L &lsqb;interquartile range of 9.5 to 34.5 μg/L] versus 5.9 μg/L &lsqb;interquartile range of 3.4 to 13.9 μg/L]; P = .001) compared to non-ED patients. The cutoff values for identifying ED were 7.9 μg/L for random GH and 5.3 μg/L for GH nadir after oral administration of 75 g of glucose. There was no significant difference in total testosterone levels between the two groups (6.36 ± 4.24 nmol/L versus 9.54 ± 5.50 nmol/L; P = .299). The NO levels in patients with acromegaly were significantly lower than those in nonacromegalic controls (8.77 ± 1.78 μmol/L versus 19.19 ± 5.02 μmol/L, respectively; P = .049). Furthermore, the NO levels were even lower in ED patients than those in non-ED patients (5.14 ± 0.98 μmol/L versus 12.09 ± 3.44 μmol/L; P = .027).Conclusion: Our study showed that ED is prevalent in male acromegalic patients and may be associated with systemic endothelial dysfunction induced by excessive GH. Further studies investigating the mechanism of GH and ED are required.Abbreviations: Acro-QoL = Acromegaly Quality of Life; ED = erectile dysfunction; FSH = follicle-stimulating hormone; GH = growth hormone; IGF-1 = insulin-like growth factor 1; IIEF-5 = international index of erection function-5; LH = luteinizing hormone; MRI = magnetic resonance imaging; NO = nitric oxide; OGTT = oral glucose tolerance test; QoL = quality of life; ROC = receiver operating characteristic     

Serum Adiponectin And Insulin-Like Growth Factor 1 In Predominantly Female Patients With Thyroid Cancer: Association With The Histologic Characteristics Of The Tumor

Objective: Insulin-like growth factor (IGF)-1 and adiponectin have been proposed to contribute to the pathogenesis of different malignancies. However, data regarding their association with histologic characteristics of thyroid cancer are scarce. The main aims of the present study were the comparative evaluation of IGF-1, IGF-binding protein 3 (BP3), and adiponectin serum levels between different histologic types of thyroid cancer, as well as within specific histologic characteristics of the tumors.Methods: A total of 179 thyroid cancer patients (126 [70.4%] women) were recruited. A total of 129 (72.1%) had papillary thyroid carcinoma (including variants), 26 had follicular thyroid carcinoma (14.5%), and 24 had medullary thyroid carcinoma (13.4%). Parameters from history, physical examination, and thyroid histology were selected. Serum adiponectin, IGF-1, and IGF-BP3 were measured in fasting morning samples.Results: IGF-1, IGF-BP3, and adiponectin levels were similar among different histologic types of thyroid carcinoma, with a trend towards higher IGF-1 and IGF-BP3 levels in patients with intrathyroid invasion, compared to those without. In addition, ratios of IGF-1 to adiponectin (P = .012) and IGF-1 to (adiponectin × IGF-BP3) (P = .003), as well as type 2 diabetes (P = .001), were positively associated with tumor size.Conclusion: Although IGF-1, IGF-BP3, and adiponectin were not separately different between groups or within specific histologic lesions, when they were combined to produce IGF-1 to adiponectin and IGF-1 to (adiponectin × IGF-BP3) ratios, they were independently associated with tumor size. Future prospective studies are needed to evaluate whether these ratios could serve as prognostic markers of thyroid tumor aggressiveness.Abbreviations:CI = confidence intervalIGF-1 = insulin-like growth factor-1IGF-1R = insulin-like growth factor 1 receptorIGF-BP3 = insulin-like growth factor binding protein 3MTC = medullary thyroid carcinomaOR = odds ratioPTC = papillary thyroid carcinomaPTC-fv = papillary thyroid carcinoma-follicular variantT2DM = type 2 diabetes mellitus