Visceral fat area (VFA) is a better predictor of cardiovascular outcomes and all-cause mortality in patients on hemodialysis compared with coronary artery calcification (CAC) score, a recent study suggests.
The study included 97 Chinese patients on hemodialysis (HD). They had a median VFA and CAC score at baseline of 64.5 cm2 and 0.9, respectively. Cardiovascular events (CVEs) occurred in 20 patients (20.6%) during a median follow-up of 26.4 months. Cardiovascular death (CVD) and all-cause mortality rates were 8.2% and 11.3%, respectively. A VFA of 71.3 cm2 or higher was significantly associated with a 9.2-fold increased risk for CVEs compared with a VFA of less than 71.3 cm2, Yuqin Xiong, MD, of West China Hospital, Sichuan University in Chengdu, China, and colleagues reported in the Journal of Renal Nutrition. Each 1 cm2 increase in VFA was significantly associated with an 11% increased risk for CVD and 8% increased risk for all-cause mortality. CAC score was not significantly associated with CVEs, CVD, or all-cause mortality.
In addition, VFA was significantly correlated with cardiac structure parameters and development of left ventricular hypertrophy (LVH), according to the investigators. Each 1 cm2 increase in VFA was associated with 2% increased odds of LVH development.
“Increased VFA can be used as an independent predictor for CVEs, CVD, and all-cause mortality,” the authors concluded. “The effect VFA exerts on cardiac reconstruction might be the underlying mechanism.”
Study patients ranged in age from 35 to 62 years. Of the 97 patients, 60 (61.9%) were male. The median dialysis vintage was 10 months. Investigators measured VFA using bioelectrical impedance analysis and determined CAC score using dual-source computed tomography scanning. They used echocardiography to ascertain left ventricular mass index.
Dr Xiong and colleagues acknowledged that their study had limitations. The sample size was relatively small and they could not rule out patient selection bias. “For instance, patients who had relatively short dialysis vintage or low levels of serum hemoglobin or albumin were more likely to [give] consent [for] the study.” In addition, the investigators noted that they lacked data regarding subsequent measuring of VFA, CAC, or echocardiography “to further identify their causal relationships without outcomes.”
Xiong Y, Yu Y, Jiang H, et al. Visceral fat area is a better predictor than coronary artery calcification score for cardiovascular outcomes and all-cause death in patients on hemodialysis. J Ren Nutr. 2021;31:306-312. doi:10.1053/j.jrn.2020.08.009