Older females with late-onset hypertension are at higher CKD risk than males

Background — Females develop hypertension later and are less likely to receive chronic kidney disease (CKD) prevention treatments. The long-term impact of these differences remains unclear. We aimed to investigate sex-based differences in the in CKD outcomes among older adults with hypertension.

Methods — We conducted a population-based retrospective cohort study of adults aged ≥66 years with new hypertension using linked health data from Ontario, Canada (1 January 2010, to 31 December 2021). The primary composite outcome was a 40% decline in estimated glomerular filtration rate (eGFR) or kidney failure. We used Cox proportional hazards models to calculate hazard ratios (HRs) and Fine–Gray models accounting for death as a competing risk (subdistribution HRs, sHRs).

Results — Incident hypertension developed in 121 490 individuals (57.7% female; mean age 73.1 years; mean eGFR 83.2 mL/min/1.73 m²; median follow-up 6.8 years), 17 343 (14.3%) experienced the composite kidney outcome. The crude incidence rate per 1000 person-years was higher for females compared with males (22.0 in females vs 21.1 in males; P < .001). Females had a higher adjusted risk of the primary outcome, after accounting for death {sHR 1.10 [95% confidence interval (CI) 1.07–1.14]}. Females had a higher crude incidence of eGFR <60 mL/min/1.73 m² than males (66.6 vs 59.4; P < .001), and a higher adjusted risk [sHR 1.15 (95% CI 1.13–1.18)]. For eGFR <45 mL/min/1.73 m², females had a higher crude incidence (19.2 vs 17.5; P < .001) and a higher adjusted risk [sHR 1.13 (95% CI 1.10–1.17)] compared with males.

Conclusion — Older females with new onset hypertension were more likely to develop a 40% decline in eGFR or kidney failure compared with older males. This study will inform hypertension management practices in aging populations.