Systematic review and meta-analysis of diabetes mellitus, cardiovascular and respiratory condition epidemiology in sexual minority women

OBJECTIVE: Sexual minority women (SMW) experience higher chronic disease risk factors than heterosexual counterparts. However, it was unclear if these risks translate into higher physical condition rates. This systematic review evaluates cardiovascular disease (CVD), hypertension, respiratory disease and diabetes mellitus in SMW. METHODS: A protocol was registered with the Prospero database (CRD42016050299). Included were studies reporting mortality, incidence or prevalence of the above-listed conditions in SMW compared with heterosexual women. Databases (platforms) searched from 2010 to December 2016 were Medline (Ovid), Embase (Elsevier), Cumulative Index to Nursing and Allied Health Literature (Elsevier), PsycINFO (Ovid), Social Policy and Practice (Ovid), Cochrane CENTRAL (Cochrane Library), Science Citation Index (Web of Science), and CAB Abstracts (Ovid). Search terms included Medical Subject Heading (MeSH) terms and text words. Extensive additional searches were conducted in specialist academic journals and websites. Two reviewers checked study eligibility. One independently extracted data and assessed quality, checked by a second reviewer, with disagreements resolved through discussion. The Critical Appraisal Skills Programme cohort checklist was used to assess risk of bias. Meta-analysis was conducted where more than four studies reported the same outcomes, with Comprehensive Meta-Analysis software, using adjusted ORs (AORs) and random-effects models. Heterogeneity was assessed using I(2) test. RESULTS: Identified were 23 103 citations, 692 full texts screened and 16 studies included (in 18 papers). One reported mortality (from Denmark), none incidence and 15 prevalence (14 USA, 1 Australia). Same-sex cohabiting women had higher mortality rates compared with opposite-sex cohabiting women in CVD (HR=1.37 (95% CI 1.22 to 1.54)) and respiratory disease (HR=2.10 (95% CI 1.74 to 2.53)). AOR meta-analyses of seven studies showed higher asthma rates in lesbians (OR=1.44 (95% CI 1.27 to 1.64), I(2)=0%) and bisexual women (OR=1.64 (95% CI 1.41 to 1.89), I(2)=0%) but no differences for CVD (5 studies), hypertension (5 studies) or diabetes mellitus (7 studies). CONCLUSIONS: These new health estimates require further confirmatory epidemiological studies, and investigation into potential environmental, hormonal, physiological, psychological or genetic causes. This would be supported by routine collection of sexual identity measures in population-level epidemiological surveys.