Hepatic Steatosis Index and Chronic Kidney Disease among Middle-Aged Individuals: A Large-Scale Study in Japan

BACKGROUND: Though nonalcoholic fatty liver disease (NAFLD) is related to chronic kidney disease (CKD), it is unclear whether the hepatic steatosis index (HSI), a screening tool for NAFLD, is related to CKD. The present study investigated the relationship between HSI and CKD among middle-aged individuals in Japan. METHODS: Subjects were adults (aged 40–64 years) who received an annual health checkup in Japan between April 2013 and March 2014. Height and weight were measured, and venous blood samples were obtained to determine alanine aminotransferase (ALT), aspartate aminotransferase (AST), and creatinine levels. HSI was calculated by the following formula: HSI = 8 × ALT/AST ratio + body mass index (+2, if diabetes; +2, if female). CKD was defined as an estimated glomerular filtration rate < 60 mL/min/1.73 m(2) and/or urinary protein of ≥ (+). Logistic regression analysis was performed to estimate the odds ratio (OR) and its 95% confidence interval (CI) for CKD. RESULTS: Data of 94,893 adults were analyzed. Compared with men with an HSI < 30, men with 30 ≤ HSI ≤ 36 (OR: 1.50, 95% CI: 1.40–1.61) and HSI > 36 (OR: 2.14, 95% CI: 1.99–2.31) had significantly higher ORs for CKD. Moreover, there was a significant dose-response relationship between HSI and CKD (P for trend < 0.001). Even after adjusting for confounders, the significant results persisted. These findings in men were similar to those in women. CONCLUSIONS: This study showed that the HSI was associated with CKD among middle-aged adults in Japan. Additionally, a dose-response relationship of HSI to CKD was observed. The present study suggested that it might be useful to monitor the HSI among middle-aged individuals to detect CKD at an early stage.