Renal Outcomes With Chlorthalidone Versus Hydrochlorothiazide

The Diuretic Comparison Project (DCP) previously demonstrated cardiovascular outcomes among individuals with and without chronic kidney disease (CKD; estimated glomerular filtration rate [eGFR] <60 mL/min) at baseline.

Researchers led by Areef Ishani evaluated renal outcomes from the DCP comparing chlorthalidone (CTD) with hydrochlorothiazide (HCTZ) in patients with hypertension. They presented results at the National Kidney Foundation Spring Clinical Meetings. Hypertension is a risk factor for the development and progression of CKD, and previous research has suggested there is a greater rate of progression of eGFR and a greater incidence of CKD with CTD versus HCTZ.

Participants were randomized to either continue HCTZ or switch to CTD at pharmacologically comparable doses. The primary outcome was CKD progression: doubling of creatinine, a terminal eGFR <10 mL/min, or kidney failure requiring treatment. Researchers also assessed the total slope of eGFR and incident CKD.

There were 12,024 (89%) patients with a baseline and at least one follow-up creatinine measurement (6002 receiving CTD, 6022 receiving HCTZ). The average baseline eGFR was 71 mL/min, and mean duration of follow-up was 2.4 years.

Primary composite renal outcomes between the 217 (3.6%) CTD patients and the 232 (3.9%) HCTZ patients did not differ (hazard ratio, 0.94; 95% CI, 0.78-1.13; P=.5). Nor was there a difference between the CTD group (−0.6) compared with the HCTZ group (−0.6 mL/min/year; P=.4) in median total slope of eGFR change. Finally, there was no difference in the incidence of CKD between the CTD (16.5%) and HCTZ (16.8%) groups (P=.8).

In conclusion, among patients with hypertension, there was no difference in the primary outcome of CKD progression between the CTD and HCTZ groups. Similarly, the slope of eGFR progression and the incidence of CKD was similar in both groups.

Source: Ishani A, Hau C, Cushman W, Taylor A, Ferguson R, Leatherman S. Treatment with chlorthalidone vs hydrochlorothiazide and renal outcomes: the Diuretic Comparison Project (DCP). Presented at the National Kidney Foundation Spring Clinical Meetings 2024; May 14-18, 2024; Long Beach, California.