Serum 25(OH)D and adipokines levels in people with abdominal obesity

Abdominal obesity is a risk factor for cardiovascular disease and diabetes mellitus and has been associated with vitamin D deficiency. Some studies have suggested an association between obesity and adipokine levels as well as low serum 25-hydroxyvitamin D (25(OH)D) level but the underlying mechanisms of the interlink between vitamin D status and serum leptin and adiponectin concentrations are still disputed. We included 435 residents (132 males) from St. Petersburg, Russia into this study. All subjects had physical examination and demographics noted. Blood was collected after an overnight fast and plasma glucose, insulin, serum lipids, 25(OH)D and adipokines (adiponectin and leptin) concentrations were determined at baseline in all participants. Abdominal obesity was diagnosed in 310 (71.3%) subjects (251 females and 59 males). Vitamin D insufficiency and deficiency were found in 314 (72.2%) subjects. Mean (95% CI) age, body mass index (BMI) and serum 25(OH)D for the cohort were 47.6±11.3years; 28.7±0.2kg/m² and 62.5±24.3nmol/l respectively. Serum 25(OH)D level inversely correlated with body weight, waist circumference (WC) and BMI in females but not in males, was lower in diabetic than non-diabetic subjects, and was not significantly different in subjects with and without MetS. WC was positively correlated with leptin and negatively correlated with adiponectin. We found correlation between leptin and serum 25(OH)D level (r=-0.15, p=0.01) but this finding was a characteristic seen only in women. Our study showed a high prevalence of abdominal obesity, vitamin D deficiency and insufficiency in residents from North-West region of Russia, close association between adipokine (leptin, adiponectin) concentrations as well as vitamin D status and body composition (WC, BMI). However in our study the interlink between leptin level and 25(OH)D was found only in females. Further investigations are required to study the relationship between serum 25(OH)D level, obesity and serum adipokine levels.