Association of ABSI, WWI with the activities of daily living impairment in the middle-aged and elderly population: Results from the China Health and Retirement Prospective study

Yihang Du ^* Wenjing Zhang Zizhen Chen Xueping Zhu Meng Lyu Wei Yi Yuanhui Hu

• Guang’anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China

Objective: To investigate and compare the associations of body mass index (BMI), waist circumference (WC), a body shape index (ABSI), weight-adjusted waist index (WWI), and waist-to-height ratio (WHtR) with activities of daily living (ADL) impairment among the middle-aged and elderly population in China.In this study, 8,700 participants from 2011 were included in the crosssection analysis. The prospective study used baseline data from 2011 and follow-up data from 2013, 2015, 2018, and 2020, with a total of 5,945 participants included.Binary logistic regression models were employed in cross-sectional analyses to calculate odds ratios (OR) with corresponding 95% confidence intervals (95% CI). In prospective analyses, Cox proportional hazards regression models were utilized to estimate hazard ratios (HR) with 95% CI. Restricted cubic spline curve was used to identify trends, with subgroup analyses performed. Diagnostic performance was quantified through receiver operating characteristic curve analysis, with area under the curve values computed.In the cross-sectional analysis, BMI (OR=0.98, 95% CI: 0.97-1.00) was significantly negatively associated with ADL impairment risk, while ABSI (OR=1.25, 95% CI: 1.14-1.37), WWI (OR=1.16, 95% CI: 1.09-1.24) were positively associated with ADL impairment. However, there was no significant association between WC, WHtR and ADL impairment. In the prospective study, WC, WHtR and BMI showed no significant association with ADL impairment, while ABSI (HR = 1.07, 95% CI:1.01-1.14) and WWI (HR=1.05, 95% CI: 1.01-1.10) remained positively associated with ADL impairment. Positive linear correlations were observed among ABSI, WWI, and ADL impairment and there was no difference among subgroup variables. The predictive ability of WWI was slightly higher than ABSI, with an AUC value of 0.598.ABSI and WWI were significantly associated with the risk of ADL impairment among the middle-aged and elderly population in China. ABSI and WWI had the potential to serve as superior obesity indicators for identifying individuals at higher risk for ADL impairment.