Unknown and Already Known Thyroid Abnormalities in Primary Hyperparathyroidism

Objective: Primary hyperparathyroidism (PHPT) and thyroid diseases are highly prevalent in the general population, but the putative link between the 2 conditions remains unclear.Methods: A monocentric consecutive series of 434 patients with PHPT was retrospectively evaluated by lab and ultrasonography to look for thyroid abnormalities. Patients were classified in 3 groups: without thyroid abnormalities (group 1, n = 171), with thyroid diseases not previously known (group 2a, n = 69), and thyroid diseases previously known (group 2b, n = 194).Results: In terms of thyroid disease, no significant difference was found between groups 2a and 2b, except for the significantly larger number of patients with toxic nodular goiter in group 2b. PHPT was more frequently symptomatic in group 2a than in group 2b, despite no differences in serum calcium, creatinine, parathyroid hormone (PTH), or 25-hydroxyvitamin D (25OHD) levels.Conclusion: A total of 60% of PHPT patients had a thyroid disease that was unknown prior to PHPT diagnosis in almost one-third of cases. The newly diagnosed and previously known thyroid diseases were similar, both mostly affecting postmenopausal females.Abbreviations: Ab = antibody; aPHPT = asymptomatic PHPT; 25OHD = 25-hydroxyvitamin D; PHPT = primary hyperparathyroidism; PTH = parathyroid hormone; Tg = thyroglobulin; TPO = thyroperoxidase; TSH = thyroid-stimulating hormone; US = ultrasound     

Asymptomatic Primary Hyperparathyroidism Exists in North India: Retrospective Data from 2 Tertiary Care Centers

Objective: Primary hyperparathyroidism (PHPT) has evolved into an asymptomatic disease in the west. In contrast, classic symptoms of PHPT have been reported to be common in the east. Here we describe clinical and biochemical profiles of patients diagnosed with PHPT between 2009 and 2012.Methods: This was a retrospective study conducted at 2 tertiary care centers in north India. All patients who underwent evaluation and surgery for primary hyperparathyroidism (PHPT) from January 2009 to December 2012 were included.Results: A total of 50 patients were studied between 2009 and 2012. Among them 31 (62%) were symptomatic and 19 (38%) were asymptomatic. The mean age (SD) was 48.3 (15.8) years, and the female to male ratio was 1.9:1. None of the patients had brown tumors or bone deformities. The asymptomatic group had significantly lower median adenoma weight (0.57 vs. 3.4 g, P<.05), a higher mean age (57.3 vs. 42.8 years, P<.05), and a lower median intact parathyroid hormone (iPTH) level (254.5 vs. 295 pg/mL, P<.05) compared to the symptomatic group. Adenoma weight was positively correlated with baseline serum calcium, iPTH, and alkaline phosphatase (ALP) levels.Conclusion: The asymptomatic form of PHPT was found in a significant percentage of north Indian patients in this study. Asymptomatic PHPT patients were older in age and had lower parathyroid adenoma weights and iPTH levels compared to symptomatic PHPT patients. Positive correlations were found between parathyroid adenoma weight and serum calcium, iPTH, and ALP levels.Abbreviations: ALP = alkaline phosphatase iPTH = intact parathyroid hormone MIBI = 2-methoxyisobutylisonitrile 25(OH)D = 25-hydroxyvitamin D3 PHPT = primary hyperparathyroidism PTH = parathyroid hormone     

Primary Hyperparathyroidism in the Young: Comparison with Adult Primary Hyperparathyroidism

Objective: Primary hyperparathyroidism (PHPT) is relatively common among adults but rarely encountered in children and adolescents. According to the western literature, young PHPT is different from adult PHPT and is associated with more severe hypercalcemia. PHPT in the adult Indian population is different from its western counterpart. Here we present the clinical, biochemical, and surgical characteristics of young patients with PHPT treated at our tertiary care center.Methods: PHPT patients were divided into adult (≥25 years) and young (<25 years) groups. The clinical, biochemical, hormonal, and histopathologic characteristics and treatment outcomes in the groups were compared.Results: Out of 358 patients, 47 patients were young and 311 patients were adults. The mean ages of the groups were 19 ± 4 and 45 ± 12 years, respectively. The corresponding female-to-male ratios were 1.24:1 and 3.38:1 (P<.05). The nature and frequency of presenting symptoms were comparable between the 2 groups. The most common symptom in young patients with PHPT was bone pain and was not significantly different from adults (57% vs. 61%, respectively). The most common symptom in adult PHPT was fatigue, which was also not significantly different from young patients (63% vs. 53%, respectively), The serum calcium, phosphate, 25-hydroxyvitamin D levels; alkaline phosphatase Z-score; and parathyroid hormone levels were comparable between the 2 groups. Parathyroid adenoma was the most common histopathologic finding, while hyperplasia was rare in both groups.Conclusion: We observed that young PHPT is not markedly different from its adult counterpart in an Indian population.Abbreviations: ALP = alkaline phosphatase; Ca = calcium; Cr = creatinine; iPTH = intact parathyroid hormone; 25(OH)D = 25-hydroxyvitamin D; P = phosphate; PHPT = primary hyperparathyroidism; PTH = parathyroid hormone; RR = reference range; ^99mTc sestamibi = technetium sestamibi; USG = ultrasonography     

Primary Hyperparathyroidism and Vitamin D In African Americans

ObjectivesVitamin D deficiency is more common in African Americans than in the general population or other ethnicities. Vitamin D deficiency also occurs more frequently in patients with primary hyperparathyroidism (PHPT) than in the general population. Currently, the limited data on vitamin D deficiency in African Americans with primary hyperparathyroidism (PHPT) is inconsistent as to whether the vitamin D deficiency observed in PHPT is yet even more pronounced in Africans with PHPT relative to non-African Americans with PHPT.MethodsOn the basis of biochemical, radiological, and surgical (adenoma weight) parameters, African Americans have been reported to have a more severe form of PHPT than non-African Americans. However, comparative clinical manifestations of PHPT in African Americans have not been well described.ResultsCurrent guidelines recommend vitamin D repletion in mild, asymptomatic PHPT when levels of 25-hydroxyvitamin D are less than 20 ng/mL. Studies that reported vitamin D repletion with ergocalciferol or cholecalciferol in PHPT have not stratified data according to ethnicity. Discrepancies therefore exist between repleting vitamin D in African Americans who may potentially have a more severe PHPT profile, but simultaneously a more pronounced vitamin D deficiency.ConclusionEffectively designed clinical trials are necessary to evaluate the indications, efficacy, and safety of vitamin D in African Americans with PHPT. (Endocr Pract. 2012;18:947-953)     

Urinary Calcium Excretion in Primary Hyperparathyroidism: Relationship to 25-Hydroxyvitamin D Status

ObjectiveTo determine the prevalence of vitamin D deficiency in patients with primary hyperparathyroidism (PHPT) and evaluate the relationship between urinary calcium excretion and serum 25-hydroxyvitamin D (25-OH-D) levels in patients with PHPT.MethodsWe present a case report and a review of the medical records of patients with PHPT. Of 75 patients with PHPT substantiated by hypercalcemia and increased levels of intact parathyroid hormone (iPTH), 35 were identified with laboratory evaluation of vitamin D levels and 24-hour urinary calcium excretion. These study subjects were stratified as 25-OH-D deficient, insufficient, or replete (on the basis of serum values of < 15, 15 to 25, or > 25 ng/mL, respectively). Total 24-hour urinary calcium excretion and the fractional excretion of calcium (FECa) were analyzed as a function of 25-OH-D status.ResultsOf the 35 study subjects, 14 (40%) and 13 (37%) had 25-OH-D deficiency or insufficiency, respectively. Those patients with a 25-OH-D level < 15 ng/mL had higher serum iPTH concentrations as well as lower urinary calcium excretion and FECa. No significant correlations were found, however, between 25-OH-D status and iPTH concentrations (r = -0.21; P = 0.23), total 24-hour urinary calcium excretion (r = 0.07; P = 0.7), or FECa (r = 0.04; P = 0.8).ConclusionVitamin D deficiency (25-OH-D levels < 15 ng/mL) was common in our population of patients with PHPT. Urinary calcium excretion was not significantly altered by 25-OH-D deficiency in patients with newly recognized PHPT. Measurements of total urinary calcium excretion and FECa can be reliably used to rule out familial benign hypocalciuric hypercalcemia in the initial evaluation of PHPT, regardless of 25-OH-D status. Determining 25-OH-D concentrations best assesses the vitamin D status. (Endocr Pract. 2005;11:37-42)     

Effect of High-Dose Vitamin D Repletion on Glycemic Control in African-American Males with Prediabetes and Hypovitaminosis D

Objective: This double-blind, randomized, controlled trial evaluated whether 12 months of high-dose vitamin D2 supplementation improved insulin sensitivity and secretion and glycemic status.Methods: African-American males (AAM) with prediabetes (glycosylated hemoglobin [A1C] 5.7-6.4%), hypovitaminosis D (25-hydroxyvitamin D [25OHD] 5-29 ng/mL), and prevalent medical problems were supplemented with vitamin D3 (400 IU/day) and then randomized to weekly placebo or vitamin D2 (50,000 IU). The primary outcome was the change in oral glucose insulin sensitivity (OGIS, from an oral glucose tolerance test [OGTT]) after 12 months of treatment. Secondary outcomes included other glycemic indices, A1C, and incident diabetes.Results: Baseline characteristics were similar in vitamin D-supplemented (n = 87) and placebo (n = 86) subjects completing the trial with average concentrations 14.4 ng/mL, 362 mL × min^-1 × m^-2, and 6.1% for 25OHD, OGIS and A1C, respectively. After 12 months, the vitamin D-supplemented group had a change in serum 25OHD +35 versus +6 ng/mL for placebo, P<.001; OGIS +7.8 versus -16.0 mL × min^-1 × m^-2 for placebo, P = .026; and A1C -0.01 versus +0.01% for placebo, P = .66. Ten percent of subjects in both groups progressed to diabetes. A posthoc analysis of participants with baseline impaired fasting glucose (IFG) showed that more subjects in the vitamin D subgroup (31.6%) than placebo (8.3%) returned to normal glucose tolerance, but the difference did not reach significance (P = .13).Conclusion: The trial does not provide evidence that 12 months of high-dose D2 repletion improves clinically relevant glycemic outcomes in subjects with prediabetes and hypovitaminosis D (NCT01375660).Abbreviations: AAM = African-American males A1C = glycosylated hemoglobin BMI = body mass index D2 = ergocalciferol D3 = cholecalciferol IFG = impaired fasting glucose IGT = impaired glucose tolerance JBVAMC = Jesse Brown VA Medical Center OGIS = oral glucose insulin sensitivity index OGTT = oral glucose tolerance test 25OHD = 25-hydroxyvitamin D VHA = Veterans Health Administration     

The Clinical Presentation of Primary Hyperparathyroidism: A Southern European Perspective Over the Last 2 Decades

Objective: The clinical presentation of primary hyperparathyroidism (PHPT) has changed widely in developed countries in the last few decades. We evaluated its variations in our series over a 20-year period (i.e., 1997–2016).Methods: A retrospective survey was conducted in our series of 364 well-characterized consecutive patients, arbitrarily divided into 4 consecutive 5-year periods at diagnosis.Results: In the overall series, only estimated glomerular function (eGFR) and urinary calcium (UCa) showed a significant upward trend (P = .032 and .039, respectively), whereas demographic and clinical characteristics were stable. The UCa upward trend was also confirmed for the subgroup of symptomatic patients (P = .013). No difference was observed in the demographic, clinical, or biochemical characteristics of asymptomatic patients or in the fraction of patients meeting surgical criteria.Conclusion: The clinical presentation of PHPT was stable over 20 years in our large series.Abbreviations: Ca = calcium; eGFR = estimated glomerular filtration rate; 25OHD = 25-hydroxyvitamin D; PHPT = primary hyperparathyroidism; PTH = parathyroid hormone; UCa = urinary calcium     

Vitamin D-Binding Protein Levels in Female Patients with Primary Hyperparathyroidism

ObjectiveTo determine whether low levels of vitamin D-binding protein (DBP) are related to 25-hydroxyvitamin D (25[OH]D) deficiency in female patients with primary hyperparathyroidism (PHPT).MethodsTwenty-five female patients with PHPT (serum calcium level >10.2 mg/dL and intact parathyroid hormone (iPTH) level >66 pg/mL) and 25 healthy age- and body mass index-matched female control subjects were xaminod. Serum calcium and iPTH levels were determined by commercial laboratories. Levels of 25(OH)D and 1,25-dihydroxyvitamin D (1,25[OH]₂D) were determined by radioimmunoassay, and DBP level was determined by enzyme-linked immunosorbent assay.ResultsSerum iPTH and calcium levels were higher in PHPT patients than control subjects (P<.001). Levels of 25(OH)D, albumin, and DBP were lower in the serum of PHPT patients than control subjects (P<.01). There were no significant differences in 1,25(OH)₂D and free 25(OH) D levels between PHPT patients and control subjects. DBP level was inversely correlated with calcium (r = -0.47; P<.01) and iPTH (r = −0.31; P<.05) levels. The 25(OH)D level correlated positively with both DBP (r = 0.28; P <.05) and albumin (r = 0.44; P<.05) levels.ConclusionsBoth serum 25(OH)D and DBP levels were lower in female patients with PHPT compared with control subjects. We suggest that a low DBP level contributes to the low 25(OH)D level observed in female PHPT patients. The etiology of the decrease in DBP and its relationship to calcium, 25(OH)D, and PTH levels require further investigation. (Endocr Pract. 2013;19:609-613)     

Hashimoto Thyroiditis not Associated with Vitamin D Deficiency

Objective: Vitamin D deficiency is associated with several autoimmune diseases. This study assessed whether vitamin D deficiency is associated with Hashimoto thyroiditis (HT).Methods: Two groups of patients were selected for which serum 25-hydroxyvitamin D (25(OH)D) levels had been measured: (1) a study group of patients diagnosed with HT as indicated by thyroid antibodies, and (2) a healthy control group. Each group was separated by sex and then controlled for age and body mass index (BMI). Groups' mean 25(OH)D levels were compared by analysis of variance (ANOVA), and percent frequencies of vitamin D sufficiency, insufficiency, and deficiency were compared with a Z-test. The correlations between 25(OH)D levels and thyroid antibodies and thyroid-stimulating hormone (TSH) levels were also tested.Results: The mean 25(OH)D levels for the HT and control groups were significantly different in females (30.75 vs. 27.56 ng/mL, respectively) but not in males (14.24 vs. 13.26 ng/mL). HT females had a higher rate of vitamin D sufficiency (51.7% vs. 31.1%) and a lower rate of insufficiency (48.3% vs. 68.9%) relative to control females. No such differences were found in the male groups. None of the females were vitamin D deficient, but almost all males were. A significant (P = .016) positive correlation (r_s = 0.436) between 25(OH)D and TPOAb was observed in males.Conclusion: HT is not associated with higher rates of vitamin D deficiency relative to a control group.Abbreviations:BMI = body mass indexHT = Hashimoto thyroiditis25(OH)D = 25-hydroxyvitamin DTgAb = thyroglobulin antibodyTSH = thyroid-stimulating hormoneTPOAb = thyroid-peroxidase antibodyVDR = Vitamin D receptor     

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     

Increased Serum Calcium is not Common in Hospitalized Patients with Primary Hyperparathyroidism: A Retrospective,Observational Study

Objective: Serum calcium levels often decrease during acute illness in patients with an intact calcium-regulating system. However, the dynamics of serum calcium levels in hospitalized patients with primary hyperparathyroidism (PHPT) have not yet been described.Methods: Clinical and laboratory data were retrospectively retrieved from the electronic medical records of patients with PHPT before, during, and after hospitalization for various reasons (excluding parathyroid surgery).Results: There were 99 nonselected patients with asymptomatic, hypercalcemic PHPT, hospitalized for various reasons; 42% were admitted for apparent infectious or septic conditions, and 58% were admitted for noninfectious conditions. Total serum calcium increased >0.5 mg/dL in 7.4% of the patients: 10.9% and 2.5% of the patients with noninfectious and infectious conditions, respectively. In 65.7% of the patients, the mean total serum calcium (TsCa), but not albumin-corrected calcium (corrCa), decreased significantly during hospitalization, down to below the upper limit of the reference range. Although prehospitalization TsCa and corrCa were similar in patients with infectious and noninfectious conditions, during hospitalization, TsCa was lower in patients with infectious conditions (P = .02). Both TsCa and albumin returned to prehospitalization levels after recovery.Conclusion: TsCa increases in a minority of hospitalized PHPT patients. In the majority of hospitalized patients with PHPT, TsCa, but not corrCa, decreases to within the normal reference range, more so in patients with infectious conditions, obscuring the major characteristic of PHPT. Therefore, it is prudent to follow calcium and corrCa during hospitalization in patients with PHPT.Abbreviations: corrCa = albumin-corrected serum calcium; IQR = interquartile range; PHPT = primary hyperparathyroidism; PTH = parathyroid hormone; TsCa = total serum calcium     

The Association Between Severity of Vitamin D Deficiency and Hashimoto's Thyroiditis

ObjectiveThe relation between vitamin D and autoimmune disorders has long been investigated regarding the important roles of this hormone in immune regulation. We evaluated 25-hydroxyvitamin D (25OHD) status in subjects with Hashimoto’s thyroiditis (HT) and healthy controls.MethodsGroup-1 included 180 euthyroid patients (123 females/57 males) with HT who were on a stable dose of L-thyroxine (LT). A total of 180 sex-, age-, and body mass index (BMI)-matched euthyroid subjects with newly diagnosed HT were considered as Group-2, and 180 healthy volunteers were enrolled as controls (Group-3). All 540 subjects underwent thyroid ultrasound and were evaluated for serum 25OHD, anti-thyroid peroxidase (anti- TPO), and anti-thyroglobulin (anti-TG) levels.ResultsGroup-1 had the lowest 25OHD levels (11.4 ± 5.2 ng/mL) compared to newly diagnosed HT subjects (Group-2) (13.1 ± 5.9 ng/mL, P = .002) and to control subjects (15.4 ± 6.8 ng/mL, P<.001). Serum 25OHD levels directly correlated with thyroid volume (r = 0.145, P<.001) and inversely correlated with anti-TPO (r = -0.361, P<.001) and anti-TG levels (r = -0.335, P<.001). We determined that 48.3% of Group-1, 35% of Group-2, and 20.5% of controls had severe 25OHD deficiency (<10 ng/mL). Female chronic HT patients had the lowest serum 25OHD levels (10.3 ± 4.58 ng/mL), and male control subjects had the highest (19.3 ± 5.9 ng/mL, P<.001).ConclusionsWe demonstrated that serum 25OHD levels of HT patients were significantly lower than controls, and 25OHD deficiency severity correlated with duration of HT, thyroid volume, and antibody levels. These findings may suggest a potential role of 25OHD in development of HT and/or its progression to hypothyroidism. (Endocr Pract. 2013;19:479-484)     

Dual-Energy X-Ray Absorptiometry And Calculated Frax Risk Scores May Underestimate Osteoporotic Fracture Risk In Vitamin D-Deficient Veterans With Hiv Infection

Objective: We evaluated the utility of the Fracture Risk Assessment Tool (FRAX) in assessing fracture risk in patients with human immunodeficiency virus (HIV) and vitamin D deficiency.Methods: This was a retrospective study of HIV-infected patients with co-existing vitamin D deficiency at the Atlanta Veterans Affairs Medical Center. Bone mineral density (BMD) was assessed by dual-energy X-ray absorptiometry (DEXA), and the 10-year fracture risk was calculated by the FRAX algorithm. Two independent radiologists reviewed lateral chest radiographs for the presence of subclinical vertebral fractures.Results: We identified 232 patients with HIV and vitamin D deficiency. Overall, 15.5% of patients met diagnostic criteria for osteoporosis on DEXA, and 58% had low BMD (T-score between -1 and -2.5). The median risk of any major osteoporotic and hip fracture by FRAX score was 1.45 and 0.10%, respectively. Subclinical vertebral fractures were detected in 46.6% of patients. Compared to those without fractures, those with fractures had similar prevalence of osteoporosis (15.3% versus 15.7%; P>.999), low BMD (53.2% versus 59.3%; P = .419), and similar FRAX hip scores (0.10% versus 0.10%; P = .412). While the FRAX major score was lower in the nonfracture group versus fracture group (1.30% versus 1.60%; P = .025), this was not clinically significant.Conclusion: We found a high prevalence of subclinical vertebral fractures among vitamin D–deficient HIV patients; however, DEXA and FRAX failed to predict those with fractures. Our results suggest that traditional screening tools for fragility fractures may not be applicable to this high-risk patient population.Abbreviations:25(OH)D = 25-hydroxyvitamin DBMD = bone mineral densityBMI = body mass indexDEXA = dual-energy X-ray absorptiometryFRAX = Fracture Risk Assessment ToolHIV = human immunodeficiency virusIQR = interquartile rangePTH = parathyroid hormoneVA = Veterans AffairsWHO = World Health Organization     

Greater Than Age-Predicted Functional Deficits In Older Patients with Primary Hyperparathyroidism

ObjectiveTo compare the functional capacity of “asymptomatic” patients with primary hyperparathyroidism (PHPT) with normative values of healthy age-matched subjects.MethodsEighteen asymptomatic patients with PHPT met the study inclusion criteria: age > 55 years, serum calcium concentration elevated ≤ 1 mg/dL above normal, inappropriate elevation of parathyroid hormone (PTH) level, and no objective symptoms of PHPT. Functional capacity was assessed by (1) a 6-minute walk test, (2) time to complete 2 sit-to-stand maneuvers, (3) gait velocity, and (4) forward reach. Serum calcium, 25-hydroxyvitamin D, and PTH levels were measured by standard laboratory assays. Functional outcomes of the study patients were compared with age-matched normative values (unpaired t test) and correlated with these biomarkers. Because these patients often have weakness, fatigue, and malaise, we hypothesized that their functional capacity would be compromised relative to that of healthy, age-matched persons.ResultsThe mean age of the patients was 65.6 years, and the mean serum calcium, PTH, and 25-hydroxyvitamin D levels (and standard deviations) were 10.36 ± 0.37 mg/dL, 122.22 ± 39.54 pg/mL, and 44.4 ± 14.27 ng/mL, respectively. Relative to normative values of healthy, agematched subjects, these patients had comparable 6-minute walk distances but required a 37% longer time to complete a repeated sit-to-stand maneuver (P < .05), demonstrated a 52% slower gait speed (P < .001), and had a greater forward reach (P = .05).ConclusionOur findings suggest that older asymptomatic patients with PHPT may have significant functional deficits that can affect their safety and quality of life. Therefore, their functional capacity should be routinely evaluated, and identified deficits should be treated with appropriate interventions. (Endocr Pract. 2012;18: 450-455)     

Low Urine Calcium Excretion in African American Patients with Primary Hyperparathyroidism

ObjectiveTo evaluate the prevalence of low urine calcium excretion in African American patients with primary hyperparathyroidism (PHPT), a common disorder associated with bone and renal complications, and to assess the distinction between PHPT and familial hypocalciuric hypercalcemia (FHH), a rare benign genetic disease.MethodsWe conducted a retrospective study on a cohort of 1,297 patients in whom a 24-hour urine study was performed for measurement of urine calcium and creatinine. PHPT was diagnosed if the serum calcium concentration was ≥ 10.5 mg/dL and intact parathyroid hormone (PTH) was ≥ 40 pg/mL. Patients receiving medications that affect urine calcium or with glomerular filtration rate ≤ 30 mL/min were excluded.ResultsNinety-six patients satisfied the diagnostic criteria for PHPT. The African American (n = 70) and non-African American (n = 26) patients did not differ in their mean age, body mass index, glomerular filtration rate, serum PTH, 25-hydroxyvitamin D levels, and 24-hour urine creatinine values. Median values of urine calcium/creatinine (mg/g) were 122 for African American versus 214 for non-African American patients (P = .006). Thirty-one of 70 African American patients (44%) had a urine calcium/creatinine ratio ≤ 100 mg/g, whereas only 2 of 26 non-African American patients (8%) had this value (P = .001).ConclusionThe prevalence of low urine calcium excretion among African American patients with PHPT is unexpectedly high. A threshold of 100 mg/g urine calcium/ creatinine identified 44% of such patients with PHPT as having FHH in this cohort. Therefore, other clinical criteria and laboratory variables should be used to distinguish PHPT from FHH in African American patients with PTH-dependent hypercalcemia. (Endocr Pract. 2011;17: 867-872)     

Identifying Parathyroid Hormone Disorders and their Phenotypes through a Bone Health Screening Panel: It's not Simple Vitamin D Deficiency!

Objectives: To determine the utility of bone health screening panels in identifying disorders of parathyroid gland secretions.Methods: A retrospective analysis of biochemical parameters in a bone health screening panel (BHSP) was conducted. Low and high cutoffs were applied to determine hypofunctioning and hyperfunctioning conditions related to parathyroid hormone. Clinical phenotypes of parathyroid gland abnormalities were determined using a combination of levels of calcium, 25-hydroxyvitamin D, and intact parathyroid hormone (iPTH). A PTH nomogram was applied to calculate the maximum expected PTH for existing levels of 25-hydroxyvitamin D. Medical records of patients were reviewed for clinical validation of biochemical findings.Results: Sixty-eight percent of subjects showed abnormal PTH secretion. Primary hyper- and hypoparathyroidism were detected in 1% (n = 5) and 0.4% (n = 2) of subjects, respectively. Normocalcemic hyperparathyroidism and hypercalcemia with inappropriately high-normal PTH were identified in 8.5% (n = 37) and 2% (n = 10) of subjects, respectively. All subjects with primary and normocalcemic hyperparathyroidism had higher measured PTH than calculated maximum PTH using the PTH nomogram. Secondary hyperparathyroidism and functional hypoparathyroidism were present in 18% (n = 88) and 39% (n = 194) of subjects, respectively. High prevalence of bone pains, renal stones, and low bone mineral density were identified in patients with abnormal PTH secretion.Conclusion: Panel testing is useful in early diagnosis of metabolic bone disorders related to PTH. A BHSP helps identify normocalcemic hyperparathyroidism and hypercalcemia with inappropriately high PTH.Abbreviations:25OHD = 25-hydroxyvitamin DAKUH = Aga Khan University HospitalBHSP = bone health screening paneliPTH = intact parathyroid hormonemaxPTH = maximum parathyroid hormoneMBD = metabolic bone diseaseNCHPT = normocalcemic hyperparathyroidismPHPT = primary hyperparathyroidismPTH = parathyroid hormoneSHPT = secondary hyperparathyroidismVDD = vitamin D deficiency     

Effectiveness and Outcomes of Current Practice in Treating Vitamin D Deficiency in Patients Listed for Liver Transplantation

Objective: Vitamin D deficiency is prevalent in cirrhotic patients awaiting liver transplantation (LT). Optimal vitamin D management for these patients remains undefined. We sought to determine the effectiveness of our practice in addressing vitamin D deficiency in LT patients.Methods: This retrospective study included 127 patients who received a first LT between July 2010 and July 2011. Outcomes measured included readmission rates, fractures, and functional status post-LT. 25-Hydroxyvitamin D (25-OH D) deficiency was stratified as: mild (20–30 ng/mL), moderate (15–19.9 ng/mL), and severe (<15 ng/mL). We estimated the amount of vitamin D supplementation required for each patient.Results: At LT evaluation, 107 patients (84%) had vitamin D deficiency, and 74% remained vitamin D deficient at LT. Only 62% received vitamin D supplementation pre-LT. Moderate and severe deficiencies were less common at LT and rare 4 months post-LT. There was an association between improvement in vitamin D deficiency category at LT and increased vitamin D (>400,000 IU total) supplementation (P = .004). We found no association between vitamin D deficiency at LT and functional status, fractures, or readmissions post-LT. Patients receiving induction immunosuppressant therapy with basiliximab had a significantly greater degree of worsening in bone mineral density (BMD) post-LT.Conclusion: Moderate-to-severe vitamin D deficiency was very prevalent in a cohort of patients undergoing evaluation for LT. Deficiency was improved with increased vitamin D replacement therapy. Vitamin D deficiency at LT was not associated with worse bone or functional outcomes post-LT. The influence of basiliximab on bone health post-LT requires further evaluation.Abbreviations: 25-OH D = 25-hydroxyvitamin D BMD = bone mineral density BMI = body mass index CI = confidence interval LT = liver transplantation MELD = Model for End-Stage Liver Disease PTH = parathyroid hormone     

Impact Of Ethnic Background On Clinical Characteristics And Cardiovascular Risk Factors Among Patients With Primary Hyperparathyroidism

Objective: To compare initial laboratory values and cardiovascular risk factors (CRF) among patients with primary hyperparathyroidism (PHPT) of different ethnic backgrounds.Methods: In this retrospective study, we reviewed 500 charts of PHPT patients who presented at Robert Wood Johnson University Hospital from January 2000 to December 2013. Among these patients were 46 African Americans (AA), 31 Asians (A), 19 Hispanics (H), and 404 Caucasians (C). The following characteristics were compared between the groups: age; body mass index (BMI); levels of serum calcium, intact parathyroid hormone (iPTH), 25-OH vitamin D, and 24-hour urine calcium; and parathyroid adenoma weight. Presence of CRF including BMI, diabetes mellitus, hypertension, and hyperlipidemia were also recorded for comparison. Associations of adenoma weight and several other parameters were also assessed.Results: Among different ethnic groups, AA patients with PHPT had higher iPTH levels compared to the A and C groups (P<.05), while 25-OHD levels were lower in the AA compared to the A and C groups (P<.05). Adenoma weight was significantly greater in AA than in C and A PHPT patients (P<.01). Adenoma weight was positively correlated with iPTH levels (r = 0.493, P <.001) and serum calcium levels (r = 0.255, P<.01). The group BMIs were C: 29.5 ± 6.9, AA: 33.8 ± 10, A: 24.7 ± 3.3, and H: 30.2 ± 6.6. AA patients had a lower rate of renal stones (9%) compared to other groups (21–29%, P<.05).Conclusion: The results of our study indicate that AA patients with PHPT presented with a more severe PHPT profile but had lower 24-hour urine calcium and fewer renal stones. AA patients with PHPT also had higher prevalence of CRF when compared to A and C.Abbreviations:A = AsianAA = African AmericanC = CaucasianCRF = cardiovascular risk factorsH = HispaniciPTH = intact parathyroid hormonePHPT = primary hyperparathyroidismPTH = parathyroid hormone     

Comparison of Vitamin D Replacement Strategies with High-Dose Intramuscular or Oral Cholecalciferol: A Prospective Intervention Study

Objective: To ascertain the frequency of correction of vitamin D deficiency (VDD) with single or multiple doses of oral (PO) and intramuscular (IM) administration of 2 high-dose preparations of vitamin D₃ (VD₃).Methods: This was a prospective intervention study conducted in an ambulatory care setting. One hundred participants with VDD (25-hydroxy vitamin D &lsqb;25-OHD] <20 ng/mL) were randomized to receive a dose of 600,000 or 200,000 IU of VD₃ via a PO or IM route. The main outcome measure was serum 25-OHD levels at 2, 4, and 6 months after the intervention.The same dose was repeated in participants if 25-OHD remained <30 ng/mL at 2 and 4 months.Results: At 2 months, VDD was corrected in 93.8% of participants in Group 1 (600,000 IU IM); 83.3% in Group 2 (600,000 IU PO), 87.5% in Group 3 (200,000 IU IM), and 70.6% in Group 4 (200,000 IU PO). The mean changes from baseline in vitamin D levels at 2 months were 29.6 ± 13.7, 19.8 ± 12.3, 18.3 ± 10.6, and 13.7 ± 7.8 ng/mL in Groups 1, 2, 3, and 4, respectively. The mean levels remained significantly higher from baseline in all groups at all time points during the 6 months of observation. The mean 25-OHD level achieved in Group 1 was significantly higher than all other groups at 6 months.Conclusion: Two months after the intervention, VDD was corrected in more than 70% of participants with a single dose of either 600,000 or 200,000 IU given PO or IM.Abbreviations: ALT = alanine transaminase IM = intramuscular iPTH = intact parathyroid hormone IQR = interquartile range 25-OHD = 25 hydroxyvitamin D PO = oral VD₃ = vitamin D3 (cholecalciferol) VDD = vitamin D deficiency VDI = vitamin D insufficiency     

Correlating Pre-Operative Vitamin D Status with Post-Thyroidectomy Hypocalcemia

Objective: To examine the relationship between pre-operative vitamin D status and post-thyroidectomy hypocalcemia.Methods: Retrospective study examining 264 total and completion thyroidectomies conducted between 2007 and 2011. Subjects included had a recorded 25-hydroxyvitamin D (25[OH]D) level within 21 days prior to or 1 day following surgery, did not have a primary parathyroid gland disorder, and were not taking 1,25-dihydroxyvitamin D₃ (calcitriol) prior to surgery. Some subjects were repleted with vitamin D pre-operatively if a low 25(OH)D level (typically below 20 ng/mL) was identified. Pre-operative 25(OH)D, concurrent neck dissection, integrity of parathyroid glands, final pathology, postoperative parathyroid hormone (PTH), calcium nadir and repletion, and length of stay were examined.Results: The mean pre-operative 25(OH)D for all subjects was 25 ng/mL, and the overall rate of post-operative hypocalcemia was 37.5%. Lower pre-operative 25(OH)D did not predict postoperative hypocalcemia (P =.96); however, it did predict the need for postoperative 1,25-dihydroxyvitamin D₃ administration (P =.01). Lower postoperative PTH levels (P =.001) were associated with postoperative hypocalcemia.Conclusion: Pre-operative 25(OH)D did not predict a postoperative decrease in serum calcium, although it did predict the need for 1,25-dihydroxyvitamin D₃ therapy in hypocalcemic subjects. We recommend that 25(OH)D be assessed and, if indicated, repleted pre-operatively in patients undergoing total thyroidectomy.Abbreviations: 25(OH)D = 25-hydroxyvitamin D PTH = parathyroid hormone