Cut off value of plasma 25-hydroxyvitamin D concentration for predicting metabolic syndrome

Background: The metabolic syndrome is a constellation of cardiometabolic risk factors that tend to cluster together in affected individuals more often than predicted by chance. The presence of the metabolic syndrome substantially increases the risk of developing type 2 diabetes and cardiovascular disease, and is associated with a range of adverse clinical outcomes, many of which are closely associated with aging. Current estimates suggest that approximately 20 - 25% of the world’s population is affected by the metabolic syndrome. The prevalence of the metabolic syndrome rises with age and more than 45% of people aged over 60 years have the metabolic syndrome. Recent studies show that low vitamin D status is very common in the world and this is a risk factor of metabolic syndrome. Objective: (1) Plasma 25-hydroxyvitamin D concentration in subjects with metabolic syndrome. (2) Cut off value of plasma 25-hydroxyvitamin D concentration for predicting metabolic syndrome. Material and method: A cross-sectional study with control group on 318 adult subjects for health examinations at International Medical Center at Hue Central Hospital, including 139 subjects with metabolic syndrome and control group of 179 healthy subjects. Metabolic syndrome was defined according to the IDF, NHLBI, AHA, WHF, IAS, IASO (2009). Plasma hydroxyvitamin D concentration was measured using chemiluminescent microparticle immunoassay. Reciever operating characteristic (ROC) curve were generated to assess sensitivity and specificity for different cut off value of 25-hydroxyvitamin D concentration for predicting metabolic syndrome. Results: Plasma 25-hydroxyvitamin D concentration in subjects with metabolic syndrome was 26.4 ng/ml, incidence of plasma 25-hydroxyvitamin D deficiency (59.7%) was significantly higher than in control group (23.5%) (p < 0.001). The optimal cut off point for 25-OH-D concentration for predictor of metabolic syndrome as 26.4 ng/ml (AUC=0.657, sensitivity=53.4%, specificity=71.6%). Conclusion: In 139 subjects with metabolic syndrome, the plasma 25-hydroxyvitamin D concentration was 26.4 ng/ml and the incidence of 25-hydroxyvitamin D deficiency in the metabolic syndrome group was 59.7%. The optimal cut off point for plasma 25-hydroxyvitamin D concentration for predictor of metabolic syndrome as 26.4 ng/ml. Key words: Metabolic syndrome, 25-hydroxyvitamin D