The relationship between cardiometabolic risks and vitamin D levels with the degree of obesity

The aim of this study was to evaluate the cardiometabolic risk factors including vitamin D levels according to the degree of obesity in adolescents.

This is a retrospective cross-sectional study. A total of 363 overweight/obese adolescents aged between 11 and 18 years who were evaluated in our clinic from January 2012 to December 2015 were included in the study. The degree of obesity was calculated as the body mass index standard deviation. Hypertension, dyslipidemia, hyperinsulinemia, hyperglycemia, insulin resistance, and vitamin D deficiency were defined as cardiometabolic risk factors. Mann-Whitney U, Chi-square, Spearman and Pearson's correlation tests, and linear regressions analyses were used for statistical analyses.

Of the 319 (n=319/363) adolescents, all of whose cardiometabolic risk factors were known, 267 (85.7%) had at least one cardiometabolic risk factor. The body mass index standard deviation had a positive correlation with the number of cardiometabolic risk factors (p<0.001). In the linear regression models in which sex and age were considered as covariates, an increase of one unit in the body mass index standard deviation led to an increase of 6.085 mm Hg in systolic blood pressure, 4.4 mm Hg in diastolic blood pressure, 1.59 points in HOMA-IR, 13% in insulin level, and a decrease of 2.16 ng/mL in vitamin D levels.

In adolescents, the number of cardiometabolic risk factors increases as the degree of obesity increases. The determination of the severity of obesity can help to identify individuals at greater risk for higher blood pressure, impaired glucose metabolism, and lower serum vitamin D levels. On the other hand, the degree of obesity may not reflect the presence of abnormal lipid and glucose levels.