Thiazide diuretics versus loop diuretics in stage 3-5 CKD: impact on cardiorenal outcomes

Objectives The association between diuretic use and cardiorenal outcomes remains limited in patients with stage 3-5 chronic kidney disease (CKD) and hypertension. To address this gap, we aim to investigate the long-term clinical impact of diuretic use with its pharmacological classification in Taiwanese patients with stage 3-5 CKD and hypertension who were concurrently received angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs). Methods Using data from the National Health Insurance Research Database (January 2008 to December 2019), we focused on individuals with stage 3-5 CKD receiving ACEIs/ARBs between 2010 and 2018. We categorized the cohort into non-diuretic, loop diuretic (furosemide), thiazide diuretic, and combination diuretic groups. We used a Cox proportional hazards regression model with propensity score matching to analyze the influence of diuretics on all-cause mortality, cardiovascular (CV) death, and cardiorenal adverse outcomes. Results The study included 59,719 patients, with 17,585 in the non-diuretic group and 42,134 in the diuretic group. Diuretics including furosemide use was significantly associated the risks of hospitalization for decompensated congestive heart failure (CHF), acute renal failure (ARF), end-stage renal disease (ESRD) requiring dialysis, CV mortality, and all-cause mortality (p-value <0.001). Thiazide diuretics showed no such adverse outcomes associations. The group receiving both thiazide and furosemide was more associated with all-cause mortality than the nondiuretic, thiazide, and furosemide monotherapy groups (all p-value <0.001). Conclusion Among stage 3-5 CKD patients on ACEIs/ARBs, loop diuretics exposure was associated with increased mortality and hospitalization for cardiorenal events, while thiazide diuretics exposure in isolation had no such associations. In the present data, we cannot evaluate the relationship between furosemide-associated adverse outcomes and worse renal function. These findings highlight the need for randomized controlled trials to assess the safety of loop diuretics in this population, urging caution in their prescription without a clear clinical indication.