Antihypertensive medications and the risk of kidney stones in older adults: a retrospective cohort study.

Antihypertensives are widely prescribed and could influence kidney stone risk by altering urinary calcium excretion. However, the impact of different classes of antihypertensives on kidney stone risk is unknown. To assess this impact, we conducted a retrospective, population-based cohort study using linked health administrative databases. Individuals aged >65 years who initiated one of the four antihypertensive classes (that is, angiotensin-converting enzyme inhibitors (ACEis)/angiotensin receptor blockers (ARBs), beta-blockers, calcium channel blockers or thiazide diuretics) were included. The participants were followed for the occurrence of a kidney stone event while maintaining continuous usage on their drug class. The association between antihypertensive class and outcome was estimated by Cox regression. Of the 542 581 people included, we observed 4533 kidney stone events (0.83%) over a median follow-up of 368 days (365-729). Compared with beta-blockers, thiazides were associated with a lower risk of kidney stones (hazard ratio (HR) 0.76; 95% confidence interval (CI) 0.68-0.84), ACEis/ARBs with a borderline decreased risk (HR 0.90; 95% CI 0.83-0.98) and calcium channel blockers with a comparable risk (HR 1.02; 95% CI 0.92-1.13). When the risk of requiring an intervention for a kidney stone was examined, the results were consistent with the primary analysis; however, the protective effect of ACEis/ARBs was eliminated (HR 0.96; 95% CI 0.87-1.06). In conclusion, relative to beta-blockers, thiazide diuretics were associated with a decreased risk of kidney stone formation in adults aged >65 years, whereas ACEis/ARBs and calcium channel blockers had a comparable risk of presenting with a kidney stone.