Abstract
BACKGROUND: Research has investigated the gamma-glutamyltransferase to high-density lipoprotein cholesterol (GGT/HDL-C) ratio concerning metabolic diseases. This study aims to explore its effects on mortality, including cardiovascular disease (CVD) mortality. METHODS: A retrospective cohort study was conducted utilizing data from the National Health and Nutrition Examination Survey (1999-2018), comprising 50,462 U.S. adults. Survival outcomes were assessed through Kaplan-Meier curves, and a multivariable Cox proportional hazards model was employed to analyze the relationship between GGT/HDL-C levels and mortality risk. Restricted cubic splines and hierarchical analyses were utilized to explore potential non-linear associations and interactions, respectively. RESULTS: During a median follow-up period of 114.4 months, 7573 deaths were recorded, including 1956 deaths related to CVD. The relationship between the GGT/HDL-C ratio and the likelihood of all-cause death and CVD death showed a J-shaped curve in the restricted cubic spline analysis. Below a lnGGT/HDL-C of 2.3 (GGT/HDL-C of 10.0), no significant correlation with all-cause mortality was identified, while the threshold for CVD death was established at lnGGT/HDL-C of 2.5. Beyond these thresholds, each unit increase in lnGGT/HDL-C was associated with a 36.3 % higher risk of all-cause mortality [HR (95 % CI), 1.36 (1.26, 1.47)] and a 67.1 % increased risk of death from CVD [HR (95 % CI), 1.67 (1.42, 1.97)]. Consistent findings were observed across various subgroups, with participants younger than 65 showing a more pronounced association. CONCLUSIONS: The GGT/HDL-C ratio exhibits a J-shaped correlation with the risk of all-cause mortality and CVD mortality among U.S. adults. This ratio may be utilized for assessing mortality risk.