Population‐Based Study on the Coexistence of Metabolic Dysfunction‐Associated Steatotic Liver Disease and Chronic Kidney Disease

Background Metabolic dysfunction‐associated steatotic liver disease (MASLD) and chronic kidney disease (CKD) are important cardiovascular risk factors. However, the prognostic impact of coexisting MASLD and CKD remains understudied. Methods This study cohort used the NHANES (National Health and Nutrition Examination Survey) 2007 to 2018 database, examining outcomes in adults with varying MASLD and CKD statuses. The primary outcome was all‐cause mortality. Secondary outcomes included coronary heart disease, heart failure, stroke, and cancer. Cox regression model was constructed to investigate the relationship between MASLD/CKD and all‐cause mortality, adjusted for age, prior coronary heart disease, body mass index, smoking, poverty‐to‐income ratio, lipid‐lowering and glucose‐lowering medications. Sensitivity analysis was performed with hepatic fibrosis and CKD. Results Among 14 818 participants (mean follow‐up: 6.9 ± 3.4 years), a majority of participants had MASLD(−)/CKD(−) (50.8%), followed by MASLD(+)/CKD(−) (34.8%), MASLD(+)/CKD(+) (7.7%), and MASLD(−)/CKD(+) (6.7%). MASLD(+)/CKD(+) (n = 1142) had the highest rates of obesity (77.6%), hypertension (77.5%), dyslipidemia (67.0%), and diabetes (49.7%), with the highest risk of coronary heart disease (risk ratio [RR], 1.79 [95% CI, 1.13–2.82], P = 0.013) and heart failure (RR 2.33 [95% CI, 1.07–5.08], P = 0.033). Socioeconomic disparities were observed, with lower‐income individuals predominantly in the group with MASLD(+)/CKD(+) ( P < 0.001). MASLD(+)/CKD(+) (adjusted hazard ratio [aHR], 3.28 [95% CI, 1.89–5.70], P < 0.001) and MASLD(−)/CKD(+) (aHR, 2.18 [95% CI, 1.33–3.66], P = 0.002) phenotypes were independent mortality predictors. Although MASLD(−)/CKD(+) and MASLD(+)/CKD(+) had unfavorable 10‐year prognoses, survival was worse in those with both hepatic fibrosis and CKD ( P < 0.001). Conclusions MASLD(+)/CKD(+) phenotype increases the risk of cardiometabolic multimorbidity and independently predicts mortality. Mortality risk increased progressively in individuals with both advanced hepatic fibrosis and CKD.