Coffee consumption and risk of the metabolic syndrome: A meta-analysis

AimsThe association between coffee consumption and risk of the metabolic syndrome (MetS) remains controversial. For this reason, a meta-analysis including dose–response analysis was conducted to quantitatively summarize the association between coffee intakes and MetS risk.MethodsA search was made of PubMed and the China National Knowledge Infrastructure (CNKI) for relevant articles published between 1 January 1999 and 31 May 2015. All observational studies related to the relationship of coffee consumption and risk of MetS were included in the meta-analysis. The result was estimated by a random-effects model, while the dose–response relationship was assessed by a restricted cubic spline model.ResultsEleven published reports including 13 studies with a total of 159,805 participants were eligible for our meta-analysis. The aggregated result (and 95% CI) for the highest vs lowest category of coffee consumption was 0.872 (0.781–0.975). After excluding one study with a relative risk (RR) < 0.300, the aggregated result (and 95% CI) was 0.889 (0.801–0.986). A non-linear relationship was found between coffee consumption and the MetS in the dose–response analysis.ConclusionThis meta-analysis suggests that coffee consumption is associated with a low risk of MetS, and further studies to address the question of causality are now needed.