LOW FREE (BUT NOT TOTAL) 25-HYDROXYVITAMIN D LEVELS IN SUBJECTS WITH NORMOCALCEMIC HYPERPARATHYROIDISM

2020 ◽  
Vol 26 (2) ◽  
pp. 174-178 ◽  
Author(s):  
Xiangbing Wang ◽  
Lingqiong Meng ◽  
Chi Su ◽  
Sue A. Shapses
Keyword(s):  
Body Mass Index ◽  
Parathyroid Hormone ◽  
Primary Hyperparathyroidism ◽  
Body Mass ◽  
Hydroxyvitamin D ◽  
Control Subjects ◽  
Healthy Control ◽  
25 Hydroxyvitamin D ◽  
The Mean ◽  
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[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

scholarly journals Sex and body mass index dependent associations between serum 25-hydroxyvitamin D and pulse pressure in middle-aged and older US adults

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jung Hyun Kwak ◽  
Yoon-Hyeong Choi
Keyword(s):  
Body Mass Index ◽  
Vitamin D ◽  
Body Mass ◽  
Pulse Pressure ◽  
Lower Risk ◽  
Hydroxyvitamin D ◽  
Vascular Stiffening ◽  
25 Hydroxyvitamin D ◽  
Dose Dependent ◽  
Overweight Subjects

AbstractHigh pulse pressure (PP) is a valid indicator of arterial stiffness. Many studies have reported that vitamin D concentration is inversely associated with vascular stiffening. This association may differ depending on sex and body mass index (BMI). This study investigated the associations between vitamin D and PP and evaluated whether these associations differ according to sex and BMI, using data for individuals aged ≥ 50 years from the National Health and Nutrition Examination Survey (NHANES) 2007–2010. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were used as biomarkers of vitamin D levels. High PP was defined as ≥ 60 mmHg. Total 25(OH)D concentrations were dose-dependently associated with lower odds ratios (ORs) for high PP (p-trend = 0.01), after controlling for sociodemographic, behavioral, and dietary factors. When stratified by sex, there was a dose-dependent association between total 25(OH)D concentrations and lower risk of high PP (p-trend < 0.001) in females, but not in males. When stratified by BMI, there was a dose-dependent association between total 25(OH)D concentrations and lower risk of high PP (p-trend < 0.001) in non-overweight subjects, but not in overweight subjects. Improving the vitamin D status could delay elevation of PP and vascular stiffening in female and non-overweight subjects.

Vitamin D Dosing Strategies Among Jordanians With Hypovitaminosis D

2016 ◽  
Vol 30 (2) ◽  
pp. 172-179 ◽  
Author(s):  
Nahla Khawaja ◽  
Mohammed Liswi ◽  
Mohammed El-Khateeb ◽  
Dana Hyassat ◽  
Dalila Bajawi ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Vitamin D ◽  
Hypovitaminosis D ◽  
Hydroxyvitamin D ◽  
Dosing Strategies ◽  
Optimal Maintenance ◽  
Group A ◽  
25 Hydroxyvitamin D ◽  
The Mean ◽  
Group B

Objective: To compare between weekly and daily cholecalciferol in patients with hypovitaminosis D and to determine the optimal maintenance dose. Methods: Seventy-one volunteers with hypovitaminosis D were randomly assigned to 2 dose regimens: cholecalciferol 50 000 IU weekly for 8 weeks, then 50 000 IU monthly for 2 months (group A) and 7000 IU daily for 8 weeks, then 12 500 IU weekly for 2 months (group B). Cholecalciferol was stopped for 2 months and reintroduced as 50 000 IU bimonthly for group A and 50 000 IU monthly for group B. Results: Two months after therapy, the mean serum 25-hydroxyvitamin D (25(OH)D) level increased from 11.4 to 51.2 ng/mL and from 11.7 to 44.9 ng/mL in groups A and B, respectively ( P = .065). The levels of 25(OH)D declined similarly in both groups during maintenance and after holding therapy. After resuming cholecalciferol, 25(OH)D levels increased to 33.8 and 28.8 ng/mL in groups A and B, respectively ( P = .027). There was a negative correlation between serum 25(OH)D levels and body mass index (BMI; P = .040). Conclusion: Timing and frequency of the dosing (daily vs weekly) have no effect on the rise in serum 25(OH)D levels as long as the accumulative dose of cholecalciferol is similar. Cholecalciferol 50 000 IU bimonthly is required to maintain sufficient 25(OH)D levels.

Cross-sectional and longitudinal relation between serum 25-hydroxyvitamin D and body mass index: the Tromsø study

2010 ◽  
Vol 49 (7) ◽  
pp. 401-407 ◽  
Author(s):  
Rolf Jorde ◽  
Monica Sneve ◽  
Nina Emaus ◽  
Yngve Figenschau ◽  
Guri Grimnes
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Cross Sectional ◽  
Hydroxyvitamin D ◽  
25 Hydroxyvitamin D

Einfluss von Body-Mass-Index, 25-hydroxyvitamin D und HbA1c auf Myostatin

2020 ◽  
Author(s):  
UG Lempert ◽  
SA Scharla ◽  
Stephan Heribert Josef Scharla
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Hydroxyvitamin D ◽  
25 Hydroxyvitamin D

scholarly journals Assay-Specific Decision Limits for Two New Automated Parathyroid Hormone and 25-Hydroxyvitamin D Assays

2005 ◽  
Vol 51 (2) ◽  
pp. 395-400 ◽  
Author(s):  
Jean-Claude Souberbielle ◽  
Véronique Fayol ◽  
Corinne Sault ◽  
Ethel Lawson-Body ◽  
André Kahan ◽  
...  
Keyword(s):  
Vitamin D ◽  
Regression Analysis ◽  
Parathyroid Hormone ◽  
Primary Hyperparathyroidism ◽  
Healthy Individuals ◽  
Hydroxyvitamin D ◽  
Low Concentrations ◽  
25 Hydroxyvitamin D ◽  
High Concentrations ◽  
Serum Pth

Abstract Background: The recent development of nonradioactive automated assays for serum parathyroid hormone (PTH) and 25-hydroxyvitamin D (25OHD) has made measurement of these two hormones possible in many laboratories. In this study, we compared two new assays for PTH and 25OHD adapted on an automated analyzer, the LIAISON®, with two manual immunoassays used worldwide. Methods: We studied 228 osteoporotic patients, 927 healthy individuals, 38 patients with primary hyperparathyroidism, and 167 hemodialyzed patients. Serum PTH was measured with the Allegro® and the LIAISON assays, and 25OHD was measured with DiaSorin RIA and the LIAISON assay. Regression analysis was used to calculate decision thresholds for the LIAISON assays that were equivalent to those of the Allegro PTH and DiaSorin 25OHD assays. Results: The 25OHD concentrations obtained with the LIAISON assay and the RIA in osteoporotic patients were well correlated (r = 0.83; P &lt;0.001). Regression and Bland–Altman analyses suggested that the LIAISON 25OHD assay reads lower than the DiaSorin RIA at low concentrations but higher at high concentrations. However, the cutoff (50 nmol/L) used in our laboratories to define vitamin D insufficiency with the DiaSorin RIA is applicable to the LIAISON 25OHD assay. In 927 healthy individuals, the 3rd–97th percentile intervals were 3–80 ng/L and 13–151 nmol/L for the LIAISON PTH and 25OHD concentrations, respectively. However, 506 individuals (54.6%) were vitamin D-insufficient; we therefore considered only the 421 individuals with a LIAISON 25OHD &gt;50 nmol/L as eligible for the reference population for the LIAISON PTH assay. In this group, the 3rd–97th percentile interval for LIAISON PTH was 3–51 ng/L. Considering upper reference limits of 46 and 51 ng/L for the Allegro and LIAISON assays, respectively, the frequency of above-normal PTH concentrations in patients with primary hyperparathyroidism was similar in both assays. Regression analysis between serum PTH measured by the Allegro and LIAISON assays in 167 hemodialyzed patients and the corresponding Bland–Altman analysis of these data suggest that the LIAISON PTH assay tends to read higher than the Allegro assay at low concentrations but lower at high concentrations (&gt;300 ng/L). Conclusions: Because clinical decision limits for both PTH and 25OHD should be assay specific, we propose equivalences between these assays and two manual assays used worldwide. These assay-specific decision limits should help potential users of the LIAISON PTH and 25OHD assays.

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