Sexual orientation disparities in physical and mental health: the influence of minority stress, biomarkers of disease, and familial factors

Despite significant changes in legislation and attitudes towards homosexuality in Sweden during the past decades, national health surveys show that gay, lesbian, and bisexual (LGB) individuals show substantially higher rates of adverse mental and physical health outcomes than heterosexuals. The reasons for these substantial health disparities are largely unknown.This study aims to compare health metrics between LGB respondents and heterosexuals. Three large Swedish population-based data sources will be used: the Stockholm Public Health Cohort, the LifeGene cohort, and a sample from the Swedish Twin Registry encompassing twins born in Sweden 1959-1985. With regression modelling, we will examine if potential differences in health outcomes among sexual orientation groups correspond to differences in various health determinants. Specifically, we propose that LGB respondents will report (a) more prejudice events or minority stressors (i.e., victimization, discrimination, perceived stress), (b) higher biological markers of cardiovascular, metabolic, and respiratory diseases risk, and (c) familial (shared environmental and genetic) risk of disease, which will account for sexual orientation-related health disparities.No study has ever examined these three explanatory factors (social, biological, and familial) simultaneously within population-based data to identify the leading causes of sexual orientation disparities in health. Major strengths of the current study include the three large cohorts with sexual orientation data in combination with the physiological and biological measures, self-report data on social stressors and lifestyle, the co-twin control design, and the high-quality registry data on health outcomes available in Sweden.The study team has extensive expertise in research concerning stigma and social/contextual and biological determinants of sexual orientation health disparities, and has a productive history of collaboration.