Serum Vitamin D and IGF1 levels in abdominal obesity women

T Karonova; O Belyaeva; E Bazhenova; D Azzi; A Berezina; N Katysheva; O Galkina; E Micheeva; E Grineva

Context: Decreased levels of both vitamin D and insulin-like growth factor 1 (IGF1) may be associated with obesity, however this had not been well established. We have examined the relationship of vitamin D status and circulating IGF1 with metabolic parameters in abdominal obesity women.

Methods: Serum 25(OH)D and IGF1 levels were measured by means of ELISA in 90 women (mean age 45.6±4.3) with abdominal obesity (according to IDF criteria, 2005). Anthropometric, metabolic measurements and standard oral glucose tolerance test were performed. The amount of adipose tissue was determined by dual-energy X-ray absorbtiometry (DEXA).

Results: The prevalence of 25(OH)D level deficiency (<50 nMol/l) and insufficiency (<75 nMol/l) was 79.6% in women with abdominal obesity. Mean 25(OH)D level was 65.1±28.1 nMol/l. 25(OH)D level was inversely associated with the total body %fat and android %fat determined by DEXA (r=−0.2, P=0.005 and r=−0.27, P=0.002 respectively). We did not find correlations of 25(OH)D levels with body mass index (BMI), waist-to-hip ratio, blood pressure and insulin level. However we found correlation of 25(OH)D level with fasting plasma glucose level (r=−0.36, P=0.003) and high-density lipoprotein (HDL) (r=−0.3, P=0.05).

Mean IGF1 level was 125.4±34.0 ng/ml. Correlation analysis revealed negative correlations between IGF1 concentration and body weight (r=−0.23, P=0.03), waist circumstance (r=−0.3, P=0.007), BMI (r=−0.28, P=0.01), android %fat (r=−0.23, P=0.04), A/G ratio (r=−0.21, P=0.05) and total fat quantity (r=−0.27, P=0.03). We did not find relationship between IGF1 level and glucose, insulin, lipids concentration as well as 25(OH)D status.

Conclusion: This study shows that both vitamin D and IGF1 concentrations are reduced in obese women and associated with the amount of adipose tissue in android region. Besides, low vitamin D levels were associated with impaired glucose and lipid metabolism.

Though no correlation between 25(OH)D and IGF1 levels were found, we are planning to continue our studies using a larger sample size for more reliable results.

Endocrine Abstracts

P317