Association between diabetes mellitus and the risk for major cardiovascular outcomes and all-cause mortality in women compared with men: A meta-analysis of prospective cohort studies

Abstract

Objective Previous studies have reported sex differences in associations between diabetes mellitus (DM) and the risk of developing coronary heart disease (CHD) and stroke; however, the risk for cardiac death and all-cause mortality in women compared with men has not been reported. Therefore, this quantitative meta-analysis was performed to provide reliable estimates of sex differences in the effect of DM on major cardiovascular outcomes and all-cause mortality, irrespective of DM type. Design Meta-analysis. Data sources The PubMed, Embase and the Cochrane Library databases were systematically searched in April 2018. Eligibility criteria Investigations designed as prospective cohort studies that examined the association between DM and major cardiovascular outcomes and all-cause mortality stratified according to sex were included. Data extraction and synthesis Data extraction and quality assessment were independently performed by 2 of the authors, and the relative risk ratio (RRR) obtained using a random effects model was used to measure sex differences in the associations of DM with major cardiovascular outcomes and all-cause mortality. Results Thirty prospective cohort studies that reported data from 1 148 188 individuals were included. The pooled women-to-men RRR suggested that female sex was associated with an increased risk for CHD (RRR 1.52(95% CI 1.32 to 1.76); p<0.001), stroke (RRR 1.23(95% CI 1.09 to 1.39); p=0.001), cardiac death (RRR 1.49(95% CI 1.11 to 2.00); p=0.009) and all-cause mortality (RRR 1.51(95% CI 1.23 to 1.85); p<0.001). In addition, sex differences for the investigated outcomes in the comparison between DM and non-DM patients were variable after stratification of studies according to publication year, country, sample size, assessment of DM, follow-up duration, adjustment for important cardiovascular risk factors and study quality. Conclusions Findings of the present study suggested that women with DM had an extremely high risk for CHD, stroke, cardiac death and all-cause mortality compared with men with DM.