Visceral adiposity index, premature mortality, and life expectancy in US adults

IMPORTANCE: Visceral adiposity index (VAI) vividly reflects body fat distribution through comprehensively integrating body mass index, sex, waist circumference, triglycerides, and high-density lipoprotein cholesterol. While VAI is an established predictor of various clinical outcomes, its relationship with premature mortality and life expectancy remains unclear. OBJECTIVE: To explore the association between VAI and premature mortality or life expectancy in a nationally representative cohort of US adults. METHODS: This study included adults who participated in the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2018, linked to the National Death Index through December 31, 2019. Data were analyzed from August to October, 2024. VAI was categorized into quartiles from the lowest Q1 to the highest Q4. Primary endpoints were premature mortality (death before 80 years of age) and life expectancy. RESULTS: A total of 43,672 participants (women: 22,164; men: 21,508) aged > 20 years were included. Over a median follow-up of 9.2 years (IQR: 4.9-13.8), 3,187 premature deaths were documented. Higher VAI quartiles were significantly associated with increased multi-adjusted premature mortality risk compared to Q1 (Q3 vs. Q1: hazard ratio HR, 95% confidence interval CI: 1.30, 1.05 to 1.61; Q4 vs. Q1: 1.68, 1.34 to 2.11). This association was particularly pronounced in women (Q3 vs. Q1: 1.53, 1.01 to 2.30; Q4 vs. Q1: 2.36, 1.52 to 3.68), with significant linear trends (P < 0.001). Estimated life expectancy at age 40 years was 41.45 (95% CI: 41.24 to 41.66), 41.32 (41.11 to 41.53), 40.55 (40.35 to 40.75), and 39.26 (39.08 to 39.45) years in Q1, Q2, Q3, and Q4 of VAI, respectively. By sex, estimated life expectancy at age 40 in Q4 was reduced by 3.33 years in women and 1.24 years in men, compared to Q1. By race and ethnicity, it was shortened by 3.90 years in Black participants and 1.68 years in White participants in Q4 group, compared to Q1. CONCLUSIONS: In this nationwide cohort study, higher VAI was significantly associated with an increased risk of premature mortality and reduced life expectancy at age 40 among US adults. These associations we heterogeneous by sex, race and ethnicity, more pronounced in women and Black participants.