Context: The literature provides no clear answer as to whether total oestradiol (E2) concentrations increase the risk of incident cardiovascular disease (CVD) in healthy men.
Objective: The authors conducted a systematic review and meta-analysis to estimate the predictive value of E2 for CVD, and to identify study features explaining conflicting results.
Data sources: Articles were identified by a Medline and Embase search and citation tracking.
Study selection: Eligible articles were prospective population-based cohorts and nested case-control studies on E2 and incident cardiovascular disease (CVD), including myocardial infarction, stroke or death from coronary heart disease. DATA-EXTRACTION: Independent researchers re-expressed associations of E2 and incident CVD in a uniform manner to be used in meta-regression analyses for identification of study features explaining conflicting results, and to estimate the predictive value of E2 for CVD.
Results and conclusions: 14 studies out of 128 electronically identified articles were eligible. Data to be used for meta-analysis could be calculated in seven cases, and in the remaining seven cases, data of three more became available by contacting those authors. Overall, a non-significant association was found with an estimated summary RR of 0.98 for a change of >75th versus <25th percentile in E2 (95% CI 0.74 to 1.31). Mean body mass index (BMI) of the study population (βs -0.8, p<0.004), and quality of E2 assay (βs -0.6, p<0.08) may have modified the relationship between E2 and incident CVD. The present systematic review does not provide evidence for a pronounced harmful or beneficial effect of E2 on risk for incident CVD in healthy men. If present, an effect of E2 on risk for CVD might be modulated by BMI.