The association between frailty and body composition among the elderly: Birjand Longitudinal Aging Study (BLAS)

This study aims to assess the possible relationship between frailty and anthropometric indices in older adults using data from the first phase of the Birjand Longitudinal Aging Study (BLAS).

In this cross-sectional study, we assessed the association between frailty (Frailty index (FI) and Fried frailty phenotype) and body composition indices in 1364 participants aged ≥ 60 years (September 2018 to April 2019). Analysis was conducted using one-way ANOVA and ordinal logistic regression.

Participants were categorized as frail (n = 164), non-frail (n = 415), and pre-frail (n = 785) based on FI. A significant positive association was observed between the frailty and body mass index (BMI) (OR: 1.04, 95% CI:1.01- 1.07), waist circumference (WC) (OR: 1.02, 95% CI: 1.01- 1.03), waist-to-hip ratio (WHR) (OR: 2.36, 95% CI 1.05- 5.27) and waist-to-height ratio (WHtR) (OR: 1.27, 95%CI: 1.09- 1.47). Body shape index, body roundness index, and body adiposity index showed no significant association with frailty. Moreover, a BMI greater than 29 kg/m² increased the odds of frailty and prefrailty by 79% (OR = 1.79, 95%CI = 1.30- 2.46, P < 0.001).

Results of this study showed that the risk of frailty increases as BMI and abdominal obesity indices increase. Therefore, BMI and abdominal obesity indices (WC, WHR, and WHtR) could serve as suitable tools for evaluating frailty in the elderly. However, additional studies are needed to evaluate the utility of the newly developed anthropometric indices in older adults.