NAFLD/MAFLD carries increased risk of nephrolithiasis

Patients with nonalcoholic fatty liver disease (NAFLD)/metabolic dysfunction–associated fatty liver disease (MAFLD) have an elevated risk of nephrolithiasis, according to a study.

Researchers used data from two cohorts, the Tianjin Chronic Low-grade Systemic Inflammation and Health Cohort Study (TCLSIH) in China and the UK Biobank. They identified 26,490 TCLSIH participants and 294,577 UK Biobank participants who had no nephrolithiasis at baseline.

Fatty liver was established using abdominal ultrasonography in the TCLSIH and the hepatic steatosis index (HSI) in the UK Biobank. MAFLD was defined according to standard clinical criteria, while nephrolithiasis was established using ultrasonography in both cohorts.

A total of 806 new cases of nephrolithiasis were recorded in the TCLSIH cohort over a median follow-up of 4 years. In the UK Biobank, 2,743 new cases of nephrolithiasis occurred over a median follow-up of 12 years.

Multivariable Cox proportional hazards regression analysis showed that NAFLD was associated with a 66-percent to 69-percent increase in the risk of nephrolithiasis in the TCLSIH (hazard ratio [HR], 1.69, 95 percent confidence interval [CI], 1.46–1.95) and the UK Biobank (HR, 1.66, 95 percent CI, 1.53–1.79) cohorts.

MAFLD was associated with a 79-percent risk increase in the TCLSIH cohort (HR, 1.79, 95 percent CI, 1.55–2.08) and 54-percent risk increase in the UK Biobank cohort (HR, 1.54, 95 percent CI, 1.42–1.66).

The findings point to NAFLD/MAFLD and their associated metabolic conditions as potential modifiable risk factors for nephrolithiasis.

The study was limited by its observational nature, limited generalizability, limited diagnostic approaches to detect nephrolithiasis, and unavailability of stone composition data.