Effect of obesity and obesity trajectories on the risk of cardiovascular diseases in adult male with incident NAFLD in Northern China

Abstract

Objective To investigate the baseline and effect of obesity and obesity trajectories on cardiovascular diseases(CVDs) in adult male with incident non-alcoholic fatty liver disease(NAFLD). Methods Adult men with newly diagnosed NAFLD and without CVDs in the Kailuan cohort study from 2006—2013 were enrolled. The subjects were divided into the nonobese group and obese group according to the definition of body mass index(BMI) or waist circumference (WC), then further divided by the obesity trajectories at the first follow-up (1-4 years). Kaplan-Meier method was used to estimate the incidence rate of CVDs for each subgroup. In addition, the Fine and Gray competing risk Cox regression model was used to compare CVDs risk in NAFLD with different baseline or trajectories in obesity measures after 1-4 years of NAFLD diagnosis. Results A total of 8 591 incident NAFLD patients were included. During a median follow-up of 9.41 years, 349 cases were found with CVDs. The 10-year cumulative incidence rates of CVDs were 3.3% and 4.3% in the nonobese and obese groups according to the definition of waist circumference, respectively (log-rank test, P＜0.05). However, the significance disappeared after adjusting the competing risk of death and other covariates. Similar results were observed based on the definition of BMI. Also, further analysis was conducted for the association trajectories in obesity measures and CVDs. The 8-year cumulative incidence rates of CVDs were 2.8%, 3.6%, 4.2%, and 3.3% in the constantly nonobese group, nonobese-obese, obese-nonobese, and constantly obese group, respectively (log-rank test, P＞0.05). Compared to the subjects with constantly nonobese defined by BMI, those who transition from nonobese to obese increased the CVDs risk by 57% (hazard ratio [HR]:1.57; 95% CI:1.03~2.38; P＜0.05). The conclusion remained even after adjusting baseline BMI (HR:1.56; 95% CI:1.02~2.37; P＜0.05). Conclusions Short-term weight gain in men with incident NAFLD led a higher CVDs risk, suggesting the importance of weight control in preventing CVDs once NAFLD occurrence.

Keywords

• obesity|non-alcoholic fatty liver disease|cardiovascular diseases|cohort study