Abdominal obesity modifies the risk of hypertriglyceridemia for all-cause and cardiovascular mortality in hemodialysis patients

Abstract

Hypertriglyceridemia is the most prevalent lipid alteration in end-stage renal disease, and we studied the relationship between serum triglycerides and all-cause and cardiovascular death in these patients. Since abdominal fat modifies the effect of lipids on atherosclerosis, we analyzed the interaction between serum lipids and waist circumference (WC) as a metric of abdominal obesity. In a cohort of 537 hemodialysis patients, 182 died, 113 from cardiovascular causes, over an average follow-up of 29 months. In Cox models that included traditional and nontraditional risk factors, there were significant strong interactions between triglycerides and WC to both all-cause and cardiovascular death. A fixed (50 mg/dl) excess in triglycerides was associated with a progressive lower risk of all-cause and cardiovascular mortality in patients with threshold WC <95 cm but with a progressive increased risk in those above this threshold. A significant interaction between cholesterol and WC with all-cause and cardiovascular death emerged only in models excluding the triglycerides-WC interaction. Neither high-density lipoprotein (HDL) nor non-HDL cholesterol or their interaction terms with WC were associated with study outcomes. Thus, the predictive value of triglycerides and cholesterol for survival and atherosclerotic complications in hemodialysis patients is critically dependent on WC. Hence, intervention studies in end-stage renal disease should specifically target patients with abdominal obesity and hyperlipidemia.