BackgroundThe association between metabolic dysfunction–associated fatty liver disease (MAFLD) and chronic kidney disease (CKD) is unclear.ObjectiveThis longitudinal cohort study aimed to test whether MAFLD plays an important role in the development of CKD.MethodsThis cohort study included 41,246 participants who had undergone 3 or more health examinations from 2008 to 2015 at the People’s Hospital of Guangxi Zhuang Autonomous Region, China. Participants were categorized into 2 groups according to whether they presented with or without MAFLD. The occurrence of new-onset CKD was stated as either an estimated glomerular filtration rate of <60 mL/min per 1.73 m2or a higher level of albuminuria during their follow-up appointment. The association between MAFLD and CKD was evaluated using a Cox regression method.ResultsOf the 41,246 participants, 11,860 (28.8%) were diagnosed with MAFLD. Over the course of the 14-year follow-up (median 10.0 years), 5347 (13%) participants experienced a new incident of CKD (135.73 per 10,000 person-years). MAFLD was discovered as an important risk factor for new incidents of CKD (hazard ratio 1.18, 95% CI 1.11-1.26) by using the multivariable Cox proportional hazard regression model. When stratified by gender, the adjusted hazard ratio for the incidence of CKD in men and women with MAFLD were 1.16 (95% CI 1.07-1.26) and 1.32 (95% CI 1.18-1.48), respectively. According to the subgroup analysis results, after adjusting for confounding factors, the MAFLD-related CKD risk was greater in men aged <60 years (Pinteraction=.001) and in those with combined dyslipidemia (Pinteraction=.02), but this relationship was not found in women (allPinteraction>.05).ConclusionsMAFLD plays an important role in the development of new incidents of CKD in the long run.Trial RegistrationChinese Clinical Trial Registry ChiCTR2200058543; https://www.chictr.org.cn/showproj.html?proj=153109