Association Between Low Chinese Visceral Adiposity Index Values and Chronic Lung Disease in Older Adults: Cohort Study.

Background: Visceral fat content, a key indicator of obesity, has been increasingly linked to chronic lung diseases (CLDs). However, the precise relationship between the Chinese visceral adiposity index (CVAI) and CLD remains unclear. Objective: This study aimed to investigate the association between the CVAI and CLD risk. Methods: Data from 6695 participants aged ≥45 years in the China Health and Retirement Longitudinal Study were analyzed. Restricted cubic spline models were applied to evaluate dose-response relationships between the CVAI and CLD across 3 population subgroups. Cox models were used to assess the hazard ratios and 95% CIs for the relationship between CVAI quintiles and CLD incidence in the significantly associated population. Results: Restricted cubic spline analysis revealed a significant L-shaped relationship between the CVAI and CLD incidence in the older adult population (≥60 years; P value for overall=.01; P value for nonlinearity=.04), rather than in the middle-aged and older adult population (≥45 years; P value for overall=.12) or middle-aged population (45-59 years; P value for overall=.55). The inflection point of the CVAI for CLD risk was identified at 126 in the older adults. After multivariable adjustment, compared with participants in the fourth quintile (Q4), those in the first quintile (Q1) exhibited a significantly increased risk of CLD (hazard ratio=1.38, 95% CI 1.05-1.83). The subgroup analyses, which were stratified by sociodemographic factors and lifestyle, showed consistent results across most subgroups (P value for interaction>.05). Conclusions: In adults aged ≥60 years, a lower CVAI was associated with a higher risk of CLD. No such association was observed in middle-aged adults.