The Mediating Effects of Metabolic Traits on the Association between Abdominal Obesity and Renal Function in Older Adults

Backgrounds: : The deleterious effects of abdominal obesity and aging have grown into a global health issue. However, relationships between abdominal obesity and renal function with aging and underlying mechanisms have not been fully elucidated. We aimed to explore associations of abdominal obesity with renal function in older individuals and further investigate potential mechanisms of metabolic traits on them. Methods: : We conducted a cross-sectional study of 4,086 participants aged 60-115 years. Generalized linear models were used to quantify dose-response relationships of abdominal obesity with metabolic traits and renal function. Mediation analysis was performed to assess mediating effects of metabolic traits in the associations between abdominal obesity and renal function. Results: We found negative dose-response relationships between waist circumstance and the estimated glomerular rate (eGFR) ( P <0.05). Abdominal obesity was associated with a 1.615 (95%CI: 0.647, 2.582) decrease in the eGFR and the decline of renal function with aging was more evident among abdominal obese participants. Significant relationships were observed between abdominal obesity and metabolic traits as well as between metabolic traits and eGFR (all P <0.05). Mediation analysis suggested that triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and total cholesterol (TCHO) partially mediated the association between abdominal obesity and eGFR, with a mediation percentage of 3.80% by LDL-C, 25.80% by TG, and 6.00% by TCHO ( P <0.05). Conclusion: Our findings suggest individuals of abdominal obesity are more susceptible to the nephrotoxic effect with aging, and highlight the metabolic pathways, especially TG, in the link of abdominal obesity with decreased renal function.