Rising serum 25-hydroxy-vitamin D levels after weight loss in obese women correlate with improvement in insulin resistance.
Τίτλος | Rising serum 25-hydroxy-vitamin D levels after weight loss in obese women correlate with improvement in insulin resistance. |
Publication Type | Journal Article |
Year of Publication | 2010 |
Authors | Tzotzas, T., Papadopoulou F. G., Tziomalos K., Karras S., Gastaris K., Perros P., & Krassas G. E. |
Journal | J Clin Endocrinol Metab |
Volume | 95 |
Issue | 9 |
Pagination | 4251-7 |
Date Published | 2010 Sep |
ISSN | 1945-7197 |
Λέξεις κλειδιά | Adult, Caloric Restriction, Cholesterol, HDL, Diet, Reducing, Female, Humans, Insulin, Insulin Resistance, Middle Aged, Obesity, Parathyroid Hormone, Up-Regulation, Vitamin D, Weight Loss |
Abstract | OBJECTIVE: The objective of the study was to examine changes of 25-hydroxy-vitamin D (25OHD) and PTH blood levels 4 and 20 wk after low-calorie diet-induced weight loss.METHODS: Forty-four obese women [aged 40.6 +/- 11.4 yr, body mass index (BMI) 36.7 +/- 4.9 kg/m(2)] and 25 controls (BMI 22.9 +/- 1.5 kg/m(2)) were examined. Anthropometric and cardiometabolic parameters and 25OHD and PTH levels were determined at baseline and 4 and 20 wk after a low-calorie diet.RESULTS: At baseline, 25OHD levels were lower in obese compared with control subjects (17 +/- 6.0 vs. 23.8 +/- 8.7 ng/ml, P < 0.001), whereas no differences were found in PTH levels. In all women, a negative correlation was found between 25OHD levels and body weight (BW) (r -0.32, P < 0.001), BMI (r -0.37, P < 0.001), waist circumference (r -0.26, P < 0.05), and percent fat mass (r -0.38, P = 0.001) as determined by bioelectrical impedance analysis. The 4-wk low-calorie diet (n = 37) reduced BW and led to significant improvements in the homeostasis model assessment (HOMA) index and lipid levels. The 20-wk low-calorie diet (n = 26) resulted in reduction of BW and BMI by 10%, HOMA index (4.7 +/- 3.8 vs. 3.10 +/- 1.7, P < 0.01), and lipids levels (except high density lipoprotein cholesterol) and increase in 25OHD (15.4 +/- 6.0 vs. 18.3 +/- 5.1 ng/ml, P < 0.05), compared with baseline. PTH levels were unchanged. The increase of 25OHD levels was associated with the reduction of insulin levels and HOMA index (r -0.43, P < 0.05).CONCLUSIONS: Blood 25OHD levels were low in obese women and correlated inversely with severity measures of obesity. Weight loss of 10% after low-calorie diet increased 25OHD levels, and this increase was mainly associated with improvement of insulin resistance. |
DOI | 10.1210/jc.2010-0757 |
Alternate Journal | J. Clin. Endocrinol. Metab. |
PubMed ID | 20534751 |