Relationship of Adipokines and Proinflammatory Cytokines Among Asian Indians With Obesity and Youth Onset Type 2 Diabetes

Objective: It is well known that inflammation is associated with diabetes, but it is unclear whether obesity mediates this association in individuals with youth-onset type 2 diabetes mellitus (T2DM-Y).Methods: We recruited individuals with T2DM-Y (age at onset <25 years) and age-matched normal glucose tolerance (NGT) subjects. Participants were further classified using Asia-Pacific body mass index cut-points for obesity and categorized as: nonobese NGT (n = 100), Obese NGT (n = 50), nonobese T2DM-Y (n = 50), and obese T2DM-Y (n = 50). We compared adipokines (adiponectin and leptin) and proinflammatory cytokines (tumor necrosis factor alpha &lsqb;TNF-α] and monocyte chemotactic protein-1 &lsqb;MCP-1]) across groups.Results: Compared to nonobese NGT, the other 3 groups (obese NGT, nonobese T2DM-Y, and obese T2DM-Y) were found to have lower adiponectin (7.7 vs. 5.7, 4.2, 3.8 μg/mL, P<.01), and higher leptin (3.6 vs. 5.4, 5.7, 7.9 μg/mL, P<.001) and MCP 1 (186 vs. 272, 340, 473 pg/mL, P<.001) respectively. However, TNF-α levels were higher only among nonobese T2DM-Y (112 pg/mL) and obese T2DM-Y (141 pg/mL, P<.01 for each). After adjusting for age, sex, waist, hypertension, homeostatic model assessment of insulin resistance (HOMA-IR), serum cholesterol, triglycerides, and family history of diabetes, adiponectin was associated with 33% and 41% lower odds of being nonobese T2DM and obese T2DM, respectively. However, adjusted for same factors, leptin, TNF-α, and MCP-1 were associated with markedly higher odds (5- to 14-fold) of nonobese and obese T2DM.Conclusion: In young Asian Indians, leptin and proinflammatory cytokines are positively, and adiponectin negatively, associated with both nonobese and obese T2DM-Y compared to nonobese NGT individuals.Abbreviations: BMI = body mass index CI = confidence interval FPG = fasting plasma glucose HOMA-IR = homeostatic model assessment of insulin resistance IGT = impaired glucose tolerance MCP-1 = monocyte chemotactic protein-1 NGT = normal glucose tolerance OGTT = oral glucose tolerance test OR = odds ratio T2DM-Y = youth-onset type 2 diabetes TNF-α = tumor necrosis factor-α     

Discovery of evocalcet,a next-generation calcium-sensing receptor agonist for the treatment of hyperparathyroidism

The calcium-sensing receptor (CaSR) plays an important role in sensing extracellular calcium ions and regulating parathyroid hormone secretion by parathyroid gland cells, and the receptor is a suitable target for the treatment of hyperparathyroidism. Cinacalcet hydrochloride is a representative CaSR agonist which widely used for the hyperparathyroidism. However, it has several issues to clinical use, such as nausea/vomiting and strong inhibition of CYP2D6. We tried to improve these issues of cinacalcet for a new pharmaceutical agent as a preferable CaSR agonist. Optimization from cinacalcet resulted in the identification of pyrrolidine compounds and successfully led to the discovery of evocalcet as an oral allosteric CaSR agonist. Evocalcet, which exhibited highly favorable profiles such as CaSR agonistic activity and good DMPK profiles, will provide a novel therapeutic option for secondary hyperparathyroidism.     

Biochemical Dynamics of Untreated Primary Hyperparathyroidism: an Observational Study

Objective: The natural biochemical history of untreated primary hyperparathyroidism (PHPT) is poorly understood. The purpose of this study was to determine the extent of biochemical fluctuations in patients with PHPT.Methods: Retrospective cohort study from January 1, 1995, to December 31, 2014. Serum calcium and parathyroid hormone (PTH) levels in patients with classic (Ca >10.5 mg/dL, PTH >65 pg/mL) and nonclassic (Ca >10.5 mg/dL, PTH 40 to 65 pg/mL) PHPT were followed longitudinally at 1, 2, and 5 years. Biochemical profiles in follow-up were ranked in descending biochemical severity as classic PHPT, nonclassic PHPT, normal calcium with elevated PTH (Ca <10.5 mg/dL, PTH >65 pg/mL), possible PHPT (Ca >10.5 mg/dL, PTH 21 to 40 pg/mL), or absent PHPT (Ca >10.5 mg/dL, PTH <21 pg/mL or Ca <10.5 mg/dL, PTH <65 pg/mL).Results: Of 10,598 patients, 1,570 were treated with parathyroidectomy (n = 1,433) or medications (n = 137), and 4,367 were censored due to study closure, disenrollment, or death. In the remaining 4,661 untreated patients with 5 years of follow-up, 235 (5.0%) progressed to a state of increased biochemical severity, whereas 972 (20.8%) remained the same, and 3,454 (74.1%) regressed to milder biochemical states. In 2,522 untreated patients with classic PHPT, patients most frequently transitioned to the normal calcium with elevated PTH group (n = 1,257, 49.8%). In 2,139 untreated patients with nonclassic PHPT, patients most frequently transitioned to the absent PHPT group (n = 1,354, 63.3%).Conclusion: PHPT is a biochemically dynamic disease with significant numbers of patients exhibiting both increases and decreases in biochemical severity.Abbreviations: IQR = interquartile range; KPSC = Kaiser Permanente Southern California; PHPT = primary hyperparathyroidism; PTH = parathyroid hormone; PTx = parathyroidectomy     

Adipogenic effect of calcium sensing receptor activation

We established that human adipose cells and the human adipose cell line LS14 express the calcium-sensing receptor (CaSR) and that its activation induces inflammatory cytokine production. Also, its expression is enhanced upon exposure to obesity-associated proinflammatory cytokines. We have thus proposed that CaSR activation may be associated with adipose dysfunction. Here, we evaluated a possible effect on adipogenesis. We induced adipose differentiation of primary and LS14 human preadipocytes with or without the simultaneous activation of CaSR, by the exposure to the calcimimetic cinacalcet. Activation of the receptor for 24 h decreased by 40 % the early differentiation marker CCAAT/enhancer-binding protein β. However, upon longer-term (10 day) exposure to the adipogenic cocktail, cinacalcet exerted the opposite effect, causing a dose–response increase in the expression of the mature adipose markers adipocyte protein 2, adiponectin, peroxisome proliferator-activated receptor γ, fatty acid synthase, and glycerol-3-phosphate dehydrogenase. To assess whether there was a time-sensitive effect of CaSR activation on adipogenesis, we evaluated the 10 day effect of cinacalcet exposure for the first 6, 24, 48 h, 6, and 10 days. Our observations suggest that regardless of the period of exposure, 10 day adipogenesis is elevated by cinacalcet. CaSR activation may interfere with the initial stages of adipocyte differentiation; however, these events do not seem to preclude adipogenesis from continuing. Even though adipogenesis (particularly in subcutaneous depots) is associated with insulin sensitivity and adequate adipose function, the implications of our findings in visceral adipocytes, especially in the context of inflamed AT and overnutrition, remain to be established.     

Low Free (But Not Total) 25-Hydroxyvitamin D Levels in Subjects with Normocalcemic Hyperparathyroidism

Objective: Normocalcemic primary hyperparathyroidism (NPHPT) is characterized by elevated parathyroid hormone (PTH) levels with persistently normal calcium levels. The diagnosis of NPHPT assumes the absence of secondary causes of elevated PTH levels. The objective of the current study was to examine levels of free 25-hydroxyvitamin D (25&lsqb;OH]D) in NPHPT subjects and healthy controls.Methods: Ten NPHPT subjects and 20 controls who were age, sex, race, and body mass index (BMI) matched were examined. The diagnosis of NPHPT was made if subjects had (1) a serum calcium level of 8.6 to 10.4 mg/dL, total 25(OH)D 30 to 40 ng/mL, and intact PTH (iPTH) ≥66 pg/mL; and (2) normal renal and liver function. Serum total 25(OH)D levels were measured by radioimmunoassay, and free 25(OH)D levels were determined using an enzyme-linked immunoassay.Results: Mean age of NPHPT subjects was 59.9 ± 5.4 years, and mean BMI was 28.4 ± 2.3 kg/m², which was not significantly different from the mean age and BMI of the control subjects. Mean total 25(OH)D level was 31.9 ± 1.7 ng/mL in NPHPT subjects and did not differ from that of the controls (32.7 ± 3.3 ng/mL; P = .52). However, mean free 25(OH)D was 5.0 ± 0.9 pg/mL in NPHPT subjects, which was 20% lower compared to the mean of the controls (6.2 ± 1.3 pg/mL; P = .013). Serum iPTH levels were inversely correlated with levels of measured free 25(OH)D (r = -0.42; P<.05) but did not correlate with levels of total 25(OH)D (r = -0.14; P>.10).Conclusion: Measured free 25(OH)D levels are lower in NPHPT subjects than in healthy control subjects. We suggest that some NPHPT subjects may actually have secondary hyperparathyroidism based on their free 25(OH) D levels.Abbreviations: 25(OH)D = 25-hydroxyvitamin D; BMI = body mass index; CV = coefficient of variation; DBP = vitamin D–binding protein; iPTH = intact parathyroid hormone; NPHPT = normocalcemic primary hyperparathyroidism     

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     

The Association of Decreased Serum Gdnf Level with Hyperglycemia and Depression in Type 2 Diabetes Mellitus

Objective: Comorbidity of diabetes and depression is a critical problem. Decreased glial-derived neurotrophic factor (GDNF) has been demonstrated in depression, but no evidence of a relationship between GDNF and diabetes has been shown. The present studies were designed to investigate the relationship between GDNF and metabolism.Methods: In Study 1, we performed a case-control study in which subjects with type 2 diabetes mellitus (T2DM), prediabetes (p-DM), and normal glucose tolerance (NGT) were included. In Study 2, we performed a cross-sectional study in 296 patients having pre-existing diabetes in whom the levels of serum GDNF, blood glucose, blood lipids, blood pressure, body mass index, scores from the Patient Health Questionnaire (PHQ-9), the EuroQol-5 scale, and the diabetes distress scale were measured, as well as single-nucleotide polymorphisms of GDNF including rs884344, rs3812047, and rs2075680.Results: In Study 1, serum GDNF concentration was significantly lower in the T2DM group than in the NGT group (NGT: 11.706 ± 3.918 pg/mL; p-DM: 10.736 ± 3.722 pg/mL; type 2 diabetes mellitus &lsqb;T2DM group]: 9.884 ± 2.804 pg/mL, P = .008). In Study 2, significantly decreased serum GDNF levels were observed in subjects with poor glycemic control or depression (glycated hemoglobin &lsqb;HbA1c] <7.0% without depression: 11.524 ± 2.903 pg/mL; HbA1c ≥7.0% without depression: 10.625 ± 2.577 pg/mL; HbA1c <7.0% with depression: 10.355 ± 2.432 pg/mL; HbA1c ≥7.0% with depression: 8.824 ± 2.102 pg/mL, P = .008). Double-factor variance analysis showed that glycemic control and depression were independent factors for the GDNF level. Moreover, the serum GDNF level was significantly inversely associated with the fasting plasma glucose, 2 hours postprandial plasma glucose, HbA1c, and PHQ-9 score.Conclusion: Glycemic dysregulation was an independent factor for the GDNF level. These findings suggest that GDNF level might be involved in the pathophysiology of T2DM and depression through various pathways.Abbreviations: BP = blood pressure; CHO = cholesterol; DDS = diabetes distress scale; DM = diabetes mellitus; EQ-5D = the health-related dimensions of the EuroQol-5 scale; FPG = fasting plasma glucose; GDNF = glial-derived neurotrophic factor; HbA1c = glycated hemoglobin; HDL = high-density lipoprotein; LDL = low-density lipoprotein; NGT = normal glucose tolerance; PHQ-9 = Patient Health Questionnaire; p-DM = prediabetes; PPG = postprandial plasma glucose; SNP = single-nucleotide polymorphism; T2DM = type 2 diabetes mellitus; TG = triglyceride     

ProGRP as a Novel Biomarker for the Differential Diagnosis of Medullary Thyroid Carcinoma in Patients with Thyroid Nodules

Objective: To investigate the release of progastrin-releasing peptide (ProGRP) in patients with thyroid nodules and the value of ProGRP in fine-needle aspirate washout fluid (FNA-ProGRP) in the differential diagnosis between medullary thyroid carcinoma (MTC) and non-MTC thyroid nodules.Methods: We investigated 2,446 healthy persons and 212 patients with 235 thyroid nodules. They were classified into healthy, nodular goiter, chronic thyroiditis, thyroid follicular neoplasm, papillary thyroid carcinoma, follicular thyroid carcinoma, and medullary thyroid carcinoma. The serum ProGRP and FNA-ProGRP were measured.Results: The serum ProGRP median concentration in MTC was 124.40 pg/mL, significantly higher than in other groups. The cutoff value of serum ProGRP was 68.30 pg/mL, leading to 53.85% sensitivity, 96.98% specificity, and 0.51 kappa value in MTC. The FNA-ProGRP median concentration in MTC nodules was 2,096.00 pg/mL, significantly higher than in other groups. A receiver operating characteristic analysis of MTC nodules and non-MTC nodules indicated that the cutoff value was 22.77 pg/mL, leading to 94.12% sensitivity, 98.27% specificity, and 0.85 kappa value.Conclusion: FNA-ProGRP measurement could be served as an ancillary method for the differential diagnosis between MTC and non-MTC thyroid nodules.Abbreviations: CEA = carcinoembryonic antigen; CT = calcitonin; FNAC = fine-needle aspiration cytology; FNA-CT = calcitonin in fine-needle aspirate washout fluid; FNA-ProGRP = ProGRP in fine-needle aspirate washout fluid; MTC = medullary thyroid carcinoma; ProGRP = progastrin-releasing peptide; SCLC = small-cell lung cancer; TM = tumor marker     

Endoscopic Ultrasound-Guided Fine-Needle Aspiration With Aspirate Assay to Diagnose Suspected Mediastinal Parathyroid Adenomas

ObjectiveTo describe our experience with mediastinal parathyroid adenomas diagnosed by endoscopic ultrasound-guided fine-needle aspiration (EUSFNA) and measurement of parathyroid hormone.MethodsWe describe the clinical and pathologic findings and diagnostic techniques used in 2 study patients.ResultsPatient 1 was a 54-year-old man with persistently elevated serum calcium and parathyroid hormone concentrations despite removal of a right inferior parathyroid adenoma. An echoendoscope was used to identify the lesion and to perform FNA. The parathyroid hormone concentration measured in the aspirated material was 1800 pg/mL. Pathologic examination of the resected specimen revealed a 29.7-g parathyroid adenoma. Patient 2 was an 86-year-old woman with recurrent hyperparathyroidism. A linear array echoendoscope was used to perform FNA of the lesion in her mediastinum. The parathyroid hormone concentration measured in the aspirated specimen was 6905 pg/mL.ConclusionsPreoperative localization of recurrent or persistent hyperparathyroidism is often difficult. EUSFNA allows evaluation of masses, such as those found in the mediastinum, that are poorly evaluated by other imaging modalities. This technique may be a useful adjunct in diagnosing mediastinal parathyroid adenomas. (Endocr Pract. 2010;16:437-440)     

Management of Hyperparathyroidism in Kidney Transplantation Candidates: A Need for Consensus

Objective: To assess the evolving standards of care for hyperparathyroidism in kidney transplant candidates.Methods: An 11-question, Institutional Review Board–approved survey was designed and reviewed by multiple institutions. The questionnaire was made available to the American Society of Transplantation's Kidney Pancreas Community of Practice membership via their online hub from April through July 2019.Results: Twenty percent (n = 41) of kidney transplant centers responded out of 202 programs in the United States. Forty-one percent (n = 17) of respondents believed medical literature supports the concept that a serum parathyroid hormone level greater than 800 pg/mL could endanger the survival of a transplanted kidney and therefore makes transplantation in an affected patient relatively or absolutely contraindicated. Sixty-six percent (n = 27) said they occasionally recommend parathyroidectomy for secondary hyperparathyroidism prior to transplantation, and 66% (n = 27) recommend parathyroidectomy after transplantation based on persistent, unsatisfactory posttransplantation parathyroid hormone levels. Forty-six percent (n = 19) prefer subtotal parathyroidectomy as their choice; 44% (n = 18) had no standard preference. Endocrine surgery and otolaryngology were the most common surgical specialties consulted to perform parathyroidectomy in kidney transplant candidates. The majority of respondents (71%, n = 29) do not involve endocrinologists in the management of kidney transplantation candidates.Conclusion: Our survey shows wide divergence of clinical practice in the area of surgical management of kidney transplantation candidates with hyperparathyroidism. We suggest that medical/surgical societies involved in the transplantation care spectrum convene a multidisciplinary group of experts to create a new section in the kidney transplantation guidelines addressing the collaborative management of parathyroid disease in transplantation candidates.Abbreviations: AACE = American Association of Clinical Endocrinologists; AAES = American Association of Endocrine Surgeons; AHNS = American Head and Neck Society; CKD = chronic kidney disease; CKD-MBD = chronic kidney disease–mineral and bone disorder; ESRD = end-stage renal disease; HPT = hyperparathyroidism; KDIGO = Kidney Disease Improving Global Outcomes; KT = kidney transplantation; KTC = kidney transplant candidate; PTH = parathyroid hormone; PTX = parathyroidectomy; US = ultrasonography     

Vitamin D-Binding Protein in Healthy Pre- and Postmenopausal Women: Relationship with Estradiol Concentrations

Objective: To examine the relationship between endogenous serum estradiol and vitamin D–binding protein (DBP) and total, free, and bioavailable 25-hydroxyvitamin D (25OHD) concentrations in pre- and postmenopausal women.Methods: In 165 healthy women (ages, 26 to 75 years) not taking any form of exogenous estrogen, the serum concentrations of estradiol, 25OHD, DBP, parathyroid hormone, and albumin were measured. Free and bioavailable 25OHD (free + albumin-bound) levels were calculated from total 25OHD, DBP, and serum albumin levels.Results: Premenopausal women had higher serum 25OHD (31.5 ± 7.9 ng/mL), DBP (45.3 ± 6.2 mg/dL), and estradiol (52.8 ± 35.0 pg/mL) levels than postmenopausal women (26.5 ± 4.9 ng/mL, 41.7 ± 5.7 mg/dL, and 12.9 ± 4.9 pg/mL), respectively. In addition, the calculated free and bioavailable 25OHD levels were higher in prethan postmenopausal women (P<.05). Serum estradiol correlated with DBP (r = 0.22; P<.01) and total 25OHD (r = 0.27; P<.01). In multivariate regression models (with or without serum 25OHD), estradiol was independently associated with DBP (P<.05).Conclusion: Lower estradiol level is one of the factors that contribute to lower DBP levels in older women. Our data indicate that besides well-known factors such as age, gender, and race, serum estradiol concentrations are also a physiologic predictor of DBP concentration.Abbreviations: 25OHD = 25-hydroxyvitamin D BMI = body mass index CV = coefficient of variation DBP = vitamin D–binding protein PTH = parathyroid hormone SHBG = sex hormone–binding globulin     

Gender differences in adiponectin and low-grade inflammation among individuals with normal glucose tolerance,prediabetes, and type 2 diabetes

Background: Women with prediabetes and type 2 diabetes mellitus have a higher relative risk of cardiovascular disease than do men. The reason for this is unknown.Objective: We studied the gender differences in adiponectin and in low-grade inflammation, measured by high-sensitivity C-reactive protein (hs-CRP) and interleukin-1 receptor antagonist (IL-1RA), in individuals with normal glucose tolerance, prediabetes, and type 2 diabetes.Methods: In this population-based, cross-sectional study, all individuals born in 1942, 1947, 1952, 1957, and 1962 in Pieksämäki, East Finland, were recruited for participation. A 75-g oral glucose tolerance test and lipid panel were performed, and concentrations of adiponectin, hs-CRP, and IL-1RA were measured. The World Health Organization diagnostic criteria for diabetes and prediabetes (impaired fasting glucose and/or impaired glucose tolerance) were used. Statistical comparisons between men and women were performed by a bootstrap-type ANCOVA.Results: The eligible population included 1294 middle-aged individuals, and of these, 904 (406 men and 498 women) had complete data and were included in the analyses. Absolute adiponectin concentrations were significantly higher in women at all levels of glucose tolerance (normal, prediabetes, and type 2 diabetes), but the gender ratio (women to men) for adiponectin concentrations decreased linearly (P = 0.011) from normal glucose tolerance (1.61; 95% CI, 1.48–1.75) to prediabetes (1.57; 95% CI, 1.36–1.83) and diabetes (1.16; 95% CI, 0.87–1.53). Among participants with normal glucose tolerance, no significant difference was found between the sexes in hs-CRP or IL-1RA. Among patients with prediabetes or diabetes, women had significantly higher concentrations than did men for hs-CRP (for prediabetes, 2.0 vs 1.5 mg/L; ratio, 1.39; 95% CI, 1.04–1.85) and IL-1RA (for prediabetes, 255 vs 178 pg/mL; ratio, 1.43; 95% CI, 1.121.83). The gender ratios (women to men) increased linearly from normal glucose tolerance to prediabetes and type 2 diabetes for both hs-CRP (P = 0.019) and IL-1RA (P = 0.013).Conclusions: Adiponectin concentrations in women decreased relatively more compared with men across individuals with normal glucose tolerance, prediabetes, and type 2 diabetes, whereas inflammatory markers increased relatively more in women. Higher inflammatory stress in women than in men with prediabetes and type 2 diabetes may explain their relatively higher cardiovascular disease risk.     

Soluble Tumor Necrosis Factor Receptor Type 1 Levels Exhibit A Stronger Association With Renal Outcomes Than Traditional Risk Factors in Chinese Subjects With Type 2 Diabetes Mellitus

Objective: Associations between albuminuria and renal outcomes are inconsistent in patients with type 2 diabetes (T2D). Soluble tumor necrosis factor receptor type 1 (sTNFR1) is involved in declined kidney function and poor renal outcomes but this has not been confirmed among Chinese T2D patients. This study aimed to examine the association of sTNFR1 and renal outcomes in a cohort of these patients.Methods: Two hundred and eighty-three Chinese T2D patients were enrolled in a prospective observational study which excluded individuals with estimated glomerular filtration rates (eGFR) <30 mL/min/1.73m². Composite renal outcomes included either or both a >30% decline in eGFR and worsening albuminuria from consecutive tests of blood/urine during a 3.5-year follow-up.Results: Higher sTNFR1 levels were associated with impaired renal outcomes. sTNFR1 levels of ≥979 pg/mL yielded the most sensitivity and specific predictions of renal outcomes according to the receiver operating curve (area under the curve 0.68, P<.001; sensitivity 78.3%, specificity 48.9%). Renal events occurred more frequently in subjects with sTNFR1 ≥979 pg/mL than in others (sTNFR1 <979 pg/mL; 29% versus 10%; P<.001 by log-rank test). The association between sTNFR1 ≥979 pg/mL and renal outcomes remained significant after adjustment for relevant covariates (adjusted hazard ratio 2.43, 95% confidence interval 1.18 to 5.02; P = .01) and consistent across subgroups stratified by age, sex, blood pressure, eGFR, albuminuria, and the use of renin-angiotensin system inhibitors.Conclusion: Increased sTNFR1 levels were associated with renal outcomes in Chinese T2D subjects, making sTNFR1 a potential biomarker in diabetic kidney disease.     

Involvement of the Calcium-sensing Receptor in Human Taste Perception

By human sensory analyses, we found that various extracellular calcium-sensing receptor (CaSR) agonists enhance sweet, salty, and umami tastes, although they have no taste themselves. These characteristics are known as “kokumi taste” and often appear in traditional Japanese cuisine. Although GSH is a typical kokumi taste substance (taste enhancer), its mode of action is poorly understood. Here, we demonstrate how the kokumi taste is enhanced by the CaSR, a close relative of the class C G-protein-coupled receptors T1R1, T1R2, and T1R3 (sweet and umami receptors). We identified a large number of CaSR agonist γ-glutamyl peptides, including GSH (γ-Glu-Cys-Gly) and γ-Glu-Val-Gly, and showed that these peptides elicit the kokumi taste. Further analyses revealed that some known CaSR agonists such as Ca²⁺, protamine, polylysine, l-histidine, and cinacalcet (a calcium-mimetic drug) also elicit the kokumi taste and that the CaSR-specific antagonist, NPS-2143, significantly suppresses the kokumi taste. This is the first report indicating a distinct function of the CaSR in human taste perception.     

Does Baseline PTH Influence Recovery of Bone Mineral Density,Trabecular Bone Score and Bone Turnover Markers? A Prospective Study Following Curative PArathyroidectomy in Primary Hyperparathyroidism

Objective: This prospective study was carried out to assess trabecular bone score, bone mineral density (BMD), and bone biochemistry in Indian subjects with symptomatic primary hyperparathyroidism (PHPT), and to study the influence of baseline parathyroid hormone (PTH) on recovery of these parameters following curative surgery.Methods: This was a 2-year prospective study conducted at a tertiary care centre in southern India. Baseline assessment included demographic details, mode of presentation, bone mineral biochemistry, BMD, trabecular bone score (TBS), and bone turnover markers (BTMs). These parameters were reassessed at the end of the first and second years following curative parathyroid surgery.Results: Fifty-one subjects (32 men and 19 women) with PHPT who had undergone curative parathyroidectomy were included in this study. The mean (SD) age was 44.6 (13.7) years. The TBS, BTMs, and BMD at lumbar spine and forearm were significantly worse at baseline in subjects with higher baseline PTH (≥250 pg/mL) when compared to the group with lower baseline PTH (<250 pg/mL). At the end of 2 years, the difference between high versus low PTH groups (mean ± SD) persisted only for forearm BMD (0.638 ± 0.093 versus 0.698 ± 0.041 g/cm²; P =.01). However, on follow-up visits in the first and second year after curative parathyroidectomy, there was no significant difference in BTMs, BMD at the femoral neck, lumbar spine, and TBS between the 2 groups stratified by baseline PTH.Conclusion: The BMD at the forearm remained significantly worse in individuals with high baseline PTH even at 2 years after surgery, while other parameters including TBS improved significantly from baseline.Abbreviations: 25(OH)D = 25-hydroxyvitamin D; BMD = bone mineral density; BMI = body mass index; BTMs = Bone turnover markers; CTX = C-terminal telopeptide of type 1 collagen; DXA = dual energy X-ray absorptiometry; P1NP = N-terminal propeptide of type 1 procollagen; PHPT = primary hyperparathyroidism; PTH = parathyroid hormone; TBS = trabecular bone score     

HRPT2- (CDC73) Related Hereditary Hyperparathyroidism: A Case Series From Western India

Objective: To describe a case series of HRPT2- (CDC73) related hereditary primary hyperparathyroidism (PHPT) from western India.Methods: We present a case series of 4 families (7 patients) with PHPT caused by CDC73 gene mutations.Results: The mean age of presentation of the 4 index cases was 27.25 ± 9.8 years. Two family members were identified through biochemical screening (Cases 1b and 2b), while 1 mutation-positive family member did not manifest any features of PHPT or hyperparathyroidism jaw tumor syndrome (HPT-JT) syndrome (Case 2c). Biochemistry showed increased serum calcium (mean: 13.21 ± 1.24 mg/dL), low serum phosphorus (mean: 1.78 ± 0.44 mg/dL), and high parathyroid hormone (PTH, mean: 936 ± 586.9 pg/mL).All patients had a uniglandular presentation and underwent single adenoma excision initially except Cases 2a and 2b, who underwent subtotal parathyroidectomy at baseline. Two cases experienced PHPT recurrence (Cases 3 and 4), while 1 remained uncured due to parathyroid carcinoma (Case 1a). Other associated syndromic features like ossifying jaw fibromas were present in 2 patients, renal cysts in 3 patients, and uterine involvement in 2 patients. Two families had novel germline CDC73 mutations (Families 1 and 3), while the other 2 had reported mutations. Family 2 had familial isolated PHPT without any other features of HPT-JT syndrome.Conclusion: Our findings reaffirm the need for genetic analysis of patients with PHPT, especially those with younger age of disease onset; recurrent disease; and associated features like polycystic kidneys, endometrial involvement, ossifying jaw tumors, or parathyroid carcinoma.Abbreviations: FIHP = familial isolated hyperparathyroidism HPT-JT = hyperparathyroidism jaw tumor syndrome PHPT = primary hyperparathyroidism PTH = parathyroid hormone ⁹⁹Tc = ⁹⁹Technetium     

Reduced Parathyroid Hormone-Stimulated 1,25-Dihydroxyvitamin D Production in Vitamin D Sufficient Postmenoposual Women with Low Bone Mass and Idiopathic Secondary Hyperparathyroidism

ObjectiveDistinguishing secondary hyperparathyroidism (sHPT) from eucalcemic primary hyperparathyroidism (EC-pHPT) is important. The objective of this study was to measure parathyroid hormone (PTH)-stimulated production of 1α,25-dihydroxyvitamin D (1,25[OH]₂D) in early postmenopausal patients with idiopathic sHPT, who also fit the criteria for EC-pHPT, compared to age-matched controls.MethodsIn this pilot case-control study, postmenopausal women aged 44 to 55 years with normal serum calcium (Ca), glomerular filtration rate (GFR) ≥65 mL/min, and 25-hydroxyvitamin D (25[OH]D) ≥75 nmol/L (30 ng/mL) were given an 8 hour infusion of PTH(1-34), 12 pmol/kg/h. Patients (n = 5) had elevated PTH, normal 1,25(OH)₂D, and no hypercalciuria. Controls (n = 5) had normal PTH. At baseline, 4, and 8 hours, serum Ca, creatinine (Cr), phosphorus (P), 1,25(OH)₂D, fibroblast growth factor (FGF23), and 24,25(OH)₂D as well as urine Ca, P, Cr, and cAMP/GFR were measured. The fractional excretion of calcium (FeCa) and tubular reabsorption of phosphorus (TMP)/GFR were calculated.ResultsPatients had lower 1,25(OH)₂D levels (± SD) than controls at 4 (39.8 ± 6.9 versus 58.8 ± 6.7; P = .002) and 8 hours (56.4 ± 9.2 versus 105 ± 2.3; P = .003) of PTH infusion, attenuated after adjusting for higher body mass index (BMI) in patients (P = .05, .04), respectively. The 24,25(OH)2D levels were lower in patients than controls (1.9 ± 0.6 versus 3.4 ± 0.6, respectively; P = .007). No differences were seen in serum Ca or P, urine cAMP/GFR, TRP/GFR, FeCa, or PTH suppression at 8 hours (patients 50%, controls 64%).ConclusionVitamin D sufficient patients who fit the criteria for EC-pHPT had reduced PTH-stimulated 1,25(OH)₂D compared to controls, partially attributable to their higher BMI. Other causes of reduced 1,25(OH)₂D production ruled out were excessive catabolism of vitamin D metabolites, elevated FGF23, and CYP27B1 mutation. Elevated BMI and idiopathic reduced PTH-stimulated 1,25(OH)₂D production should be considered in the differential of sHPT. (Endocr Pract. 2013;19:91-99)     

An improved radioreceptor assay for 1,25-dihydroxyvitamin D in human plasma

We describe a modified assay technique for quantitating 1,25-dihydroxyvitamin D in plasma. The method involves a rapid extraction of the hormone using minicolumn (made of granular diatomaceous earth) chromatography followed by single-step purification on high-performance liquid chromatography. Quantitation of plasma 1,25-dihydroxyvitamin D is achieved by a radioligand receptor assay employing lyophilized cytosolic receptor protein from chick intestine and high-specific-activity 1,25-dihydroxy[³H]vitamin D₃ (166 Ci/mmol). A new incubation medium including an ethanol extract of vitamin D-deficient chick serum yields high specific binding and improves the precision of the radioassay. Bound and free hormone are separated with dextran-coated charcoal of equivalent particle size. The method is sensitive to 0.5 pg/tube with a practical detection range of 1–20 pg/tube, permitting duplicate assay of endogenous 1,25-dihydroxyvitamin D in plasma volumes as small as 0.5 ml. The intra- and interassay coefficient of variation are 5 and 9%, respectively, and the method is valid over a wide-range sample dilution. This assay technique was applied to the measurement of plasma 1,25-dihydroxyvitamin D hormone concentration in normal young adults (55.2 ± 13.6 pg/ml; n = 20) and in patients with chronic renal failure (13.5 ± 5.2 pg/ml; n = 9) and primary hyperparathyroidism (83.3 ± 18 pg/ml; n = 10).     

Primary Hyperparathyroidism During Pregnancy: A Case Series of 8 Patients

Objective: Due to a lack of typical clinical manifestations and physiologic changes in calcium metabolism during pregnancy, primary hyperparathyroidism (PHPT) during pregnancy is commonly underdiagnosed, and treatment during this unique period presents a clinical challenge. Hence, the aim of the present study was to summarize the cases of 8 pregnant patients with PHPT who were treated at our center to provide better clinical insight into this condition.Methods: Our study comprised a retrospective analysis of 8 pregnant PHPT patients and a control group of 22 age-matched, nonpregnant PHPT patients during the same period. Clinical manifestations, biochemical indices, pathologic types, therapeutic strategies, and pregnancy outcomes were compiled, and 25 patients were screened for germline mutations in the MEN1, CDC73, and CaSR genes.Results: The most-common symptoms in the pregnancy group involved the gastrointestinal tract (GIT) in 7/8 cases (87.5%), followed by urinary system involvement (50%) and joint pain (50%). In contrast, GIT symptoms in the control group were significantly less common (31.82%; P = .012). There was a trend of more-severe elevation of serum parathyroid hormone levels in the control group compared to that in the pregnancy group (P = .053). No differences were found in blood-ionized calcium, phosphate, or alkaline phosphatase levels between the two groups. In the pregnancy group, the serum albumin-corrected calcium level was reduced from 3.42 ± 0.66 mmol/L to 2.89 ± 0.46 mmol/L (P = .025) after hydration and medical treatment. Six patients, three of whom were in the second trimester of pregnancy, underwent parathyroidectomy, and 3 patients were after childbirth or had induced labor. Postoperative serum calcium levels were reduced to within the normal range. Fetal/neonatal complications were observed in 4 of 5 patients who had not received surgical treatment during pregnancy. In addition, 2 of 5 pregnant PHPT patients were found to carry MEN1 mutations, whereas no mutations were detected in any of the 20 nonpregnant patients.Conclusion: In this case series of PHPT during pregnancy, the most-common complaint of GIT symptoms may be easily confused with pregnancy reactions, which might contribute to the under- or misdiagnosis of this clinical entity. Patients who did not receive surgical treatment during pregnancy had high incidences of fetal/neonatal complications and worse pregnancy outcomes.Abbreviations: CaSR = calcium-sensing receptor; CDC73 = cell division cycle 73; GIT = gastrointestinal tract; MEN = multiple endocrine neoplasia; PHPT = primary hyperparathyroidism; PTH = parathyroid hormone; SCa = serum calcium