Premium
Serum vitamin D levels in relation to metabolic syndrome: A systematic review and dose–response meta‐analysis of epidemiologic studies
Author(s) -
Hajhashemy Zahra,
Shahdadian Farnaz,
Moslemi Elham,
Mirenayat Fateme Sadat,
Saneei Parvane
Publication year - 2021
Publication title -
obesity reviews
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.845
H-Index - 162
eISSN - 1467-789X
pISSN - 1467-7881
DOI - 10.1111/obr.13223
Subject(s) - meta analysis , medicine , vitamin d and neurology , metabolic syndrome , physiology , endocrinology , obesity
Summary Several epidemiological studies examined the association of serum vitamin D with metabolic syndrome (MetS), but the findings were inconsistent. We conducted a systematic review and dose–response meta‐analysis to quantify the association between blood vitamin D levels and MetS in adults. A systematic search up to December 2020 was conducted in MEDLINE (PubMed), ISI (Web of Science), Scopus, and Google Scholar databases for epidemiological studies that assessed the relation of serum 25‐hydroxyvitamin D (as the exposure) and MetS (as the outcome) in adults. Eligible cross‐sectional studies were restricted to those with representative populations. Finally, 43 studies were included in the analysis (38 cross‐sectional, one nested case–control, and four cohorts studies). Combining 41 effect sizes from 38 cross‐sectional studies included 298,187 general adult population revealed that the highest level of serum vitamin D, compared with the lowest level, was significantly related to a 43% decreased odds of MetS in developed countries (odds ratio [OR]: 0.57; 95% confidence interval [CI]: 0.49–0.65) and 40% in developing countries (OR: 0.60; 95% CI: 0.52–0.70). Linear dose–response analysis (including 222,175 healthy individuals and 39,308 MetS patients) revealed that each 25 nmol/L increase in serum vitamin D level was significantly associated with a 15% decreased odds of MetS (OR: 0.85; 95% CI: 0.80–0.91); however, we found no significant nonlinear association. Meta‐analysis of five prospective studies with 11,019 participants revealed no significant relation (relative risk [RR]: 0.70; 95% CI: 0.37–1.32). This meta‐analysis indicated an inverse association between serum vitamin D concentrations and risk of MetS in general adult populations in cross‐sectional studies in a dose–response manner. However, no significant association was found in a small number of cohorts. More prospective studies are needed to confirm the causality of this relationship.