Association between obesity-related anthropometric indices and multimorbidity among older adults in Shandong, China: a cross-sectional study

OBJECTIVES: Whether the association between obesity-related anthropometric indices and multimorbidity differs by age among Chinese older adults (aged 65+) is unclear. We aimed to investigate the association between body mass index (BMI), waist circumference (WC) and waist-to-hip ratio (WHR) with multimorbidity among the young-old (aged 65–79) and old-old (aged 80+) adults. DESIGN: Cross-sectional population-based study. SETTING: Shandong province on the eastern coast of China. PARTICIPANTS: 5493 subjects aged 65 years or above. MEASUREMENTS: Details on sociodemographics, lifestyle characteristics and chronic conditions were collected using a structured questionnaire. The respondents were assessed with anthropometric measurements including height, weight, WC, hip circumference. RESULTS: The overall prevalence of multimorbidity in older adults (aged 65+) was 35.2%. The BMI-obesity, WC-obesity and WHR-obesity rates were 7.4%, 57.5% and 80.4%, respectively. In the young-old adults (aged 65–79), the likelihood of multimorbidity was more than two times higher among the BMI-obese than the BMI-normal population (OR 2.08, 95% CI 1.66 to 2.60). Similar but less strong associations were found for the WC-obese and WHR-obese young-old population (OR 1.60, 95% CI 1.42 to 1.81; OR 1.31, 95% CI 1.10 to 1.56, respectively). For the old-old group (aged 80+), the BMI-obese, WC-obese and WHR-obese had a higher likelihood of having multimorbidity compared with the normal weight category (OR 2.10, 95% CI 0.96 to 4.57; OR 1.75, 95% CI 1.21 to 2.54; OR 2.15, 95% CI 1.18 to 3.93, respectively). CONCLUSION: BMI-obesity, WC-obesity and WHR-obesity were associated with a greater risk of multimorbidity, and the associations were different between the young-old and the old-old adults. These age differences need to be considered in assessing healthy body weight in old age. These findings may be vital for public health surveillance, prevention and management strategies for multimorbidity in older adults.