Abstract
Background and Purpose:
Vitamin D can both stimulate and inhibit adipogenesis, indicating that associations of the vitamin D level with some metabolic disorders may be nonlinear. This cross-sectional study aims to explore potential nonlinear associations of the 25-hydroxy vitamin D [25(OH)D] level with metabolic syndrome (MetS) and its components.
Methods:
Adults without previously diagnosed specific noncommunicable disease were selected from the National Health and Nutrition Examination Survey 2017–2018 (n = 870). Their demographic, physical, and laboratory data were obtained. The associations of serum 25(OH)D with MetS and its components were analyzed using logistic regression. Restricted cubic spline was applied to flexibly model the nonlinear association if the nonlinearity test was statistically significant.
Results:
The 25(OH)D level was inversely associated with risk of MetS [adjusted odds ratio (OR) = 0.986; 95% confidence interval (CI) = 0.978–0.993] and most MetS components, but not with the risk of raised triglycerides (adjusted OR = 0.996; 95% CI = 0.988–1.005). The association of serum 25(OH)D with central obesity risk was significantly nonlinear (P for the nonlinearity test: 0.037). The OR for risk of central obesity decreased rapidly with increase in serum 25(OH)D concentration until the concentration reached 50 nmol/L, and then, the intensity of decrease in OR slowed down.
Conclusions:
Vitamin D is inversely associated with MetS, but not all MetS components. A nonlinear association between the vitamin D level and risk of central obesity has been found for the first time among the adult population, which reflects the complex roles of vitamin D in lipid metabolism. Although vitamin D deficiency (<50 nmol/L) was defined to avoid abnormal calcium and phosphorus metabolism, preventing its deficiency may also be beneficial for reduction of central obesity risk.
Get full access to this article
View all access options for this article.
References
Supplementary Material
Please find the following supplemental material available below.
For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.
For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.
