Abstract
BackgroundObesity is a well-established risk factor for multi-morbidity and disability among older adults in the community and acute care settings. However, nursing home residents with body mass index (BMI) below 18.5 kg/m2 and above 25.0 kg/m2 have been understudied. We examined the prevalence of multi-morbidity and disability in activities of daily living (ADL) by BMI category and further investigated the association between BMI, multi-morbidity, and disability of ADL in a large cohort of older adults in nursing homes in New Zealand.MethodsA retrospective review of nursing home residents’ data obtained from the New Zealand International Resident Assessment Instrument national dataset from 2015 to 2018. One hundred ninety-eight thousand seven hundred ninety older adults (≥60 years) living in nursing homes were included. BMI was calculated as weight in kilograms (kg) divided by height in meters squared (m2). Multimorbidity was defined as the presence of ≥2 health conditions. The risk of disability was measured by a 4-item ADL self-performance scale. The prevalence ratio (PR) of the association between BMI and multi-morbidity and between BMI and disability in ADL was assessed using Poisson regression with robust variance.ResultsOf the 198,790 residents, 10.6, 26.6, 11.3 and 5.4% were underweight, overweight, obese, and extremely obese, respectively. 26.4, 31.3 and 21.3% had one, two and three disease conditions, respectively, while 14.3% had four or more conditions. 24.1% could perform only one ADL, and 16.1% could perform none. The prevalence of multi-morbidity increased with increasing BMI, whereas mean disability in ADL decreased with increasing BMI. The risk of multi-morbidity was higher for the overweight (PR, 95%CI: 1.03, 1.02–1.03) and obese (PR, 95% CI: 1.07, 1.06–1.08) compared to normal weight after controlling for age, sex, ethnicity, and region. BMI was inversely associated with mean ADL; β, 95% CI for overweight (− 0.30, − 0.32, − 0.28) and obese − 0.43, − 0.45, − 0.40 compared to normal weight.ConclusionBeing underweight was associated with a decline in the performance of ADL in nursing home residents. In contrast, being overweight and obese positively affected functional performance, demonstrating that the obesity paradox plays an important role in this population. The observed associations highlight areas where detection and management of underweight and healthy aging initiatives may be merited.
Highlights
There is an increasing prevalence of obesity amongst older adults globally and within New Zealand; obesity rates in 65–74-year-olds and 75 years and older are estimated to be 38.3 and 26.5%, respectively [1]
A significant relationship was found between age and body mass index (BMI) (X2 = 12,054.69, df = 12, p = < 0.001); the proportion of underweight and normal weight increased with increasing age, and the proportion of overweight, obese, and extremely obese reduced with increasing age
A meaningful association was found between gender and BMI (X2 = 3606.98, df = 4, p = < 0.001), the proportion of underweight females was 2.5 times greater than that of males, but men were more highly represented in the overweight category
Summary
There is an increasing prevalence of obesity amongst older adults globally and within New Zealand; obesity rates in 65–74-year-olds and 75 years and older are estimated to be 38.3 and 26.5%, respectively [1]. Studies conducted among older adults, mainly in acute hospital and community settings, suggest that an increase in body mass index (BMI) and being older (≥65 years) predisposed an individual to multi-morbidity [2, 3], cardiometabolic comorbidity [4, 5] and decubitus ulcers [6]. Studies focusing on older adults (≥ 60 years) in nursing home residents [19,20,21] and one study of communitybased older adults aged ≥80 years [22] reported that a higher BMI significantly decreases the risk of disability in ADL. Kaiser et al [20] report that the controversial relationship between normal and low BMI ranges and functional status might apply to nursing home residents and not independently living older adults. We examined the prevalence of multi-morbidity and disability in activities of daily living (ADL) by BMI category and further investigated the association between BMI, multi-morbidity, and disability of ADL in a large cohort of older adults in nursing homes in New Zealand
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
