Sex-Based Differences in Cardiovascular Outcomes and Management Approaches in Late-Onset Hypertension

Abstract

There may be sex-based differences in the care and treatment of people with late-onset hypertension. This thesis aims to investigate the evaluation, initial pharmacological management, and important clinical outcomes, of older adults with a new diagnosis of hypertension. We conducted a population-level cohort study of all Ontario residents 66 years and older with a new diagnosis of hypertension between January 1, 2010 and December 2017. Sex was the exposure. We defined outcomes in the period of 2011 to 2021, with at least 1 year of follow-up. The first manuscript examined a primary outcome that was a composite of adverse cardiovascular events in 266,273 individuals with a new diagnosis of hypertension, defined as: any nonfatal ischemic stroke, nonfatal myocardial infarction, or congestive heart failure, by calculating hazard ratios (HR) using a Cox proportional hazards model. The second manuscript examined 111,410 individuals with a new diagnosis of hypertension but not previously on any medications that could lower blood pressure (BP), in terms of application of Hypertension Canada guideline-recommended investigations for a new diagnosis of hypertension, using Poisson regression. We also examined the initial prescription of a guideline-recommended medication for lowering blood pressure using Cox proportional hazards regression. This thesis shows that females were less likely to have the primary composite outcome despite finding no differences in performance of guideline-recommended investigations for a new diagnosis of hypertension and in prescribing of guideline-recommended medication for hypertension. Unmeasured confounding may account for some of these findings. Our findings suggest that sex-based differences in the outcomes of late-onset hypertension exist, and further studies are required to address these gaps.