Body mass index and trajectories of muscle strength and physical function over time in Mexican American older adults: Sex differences.

BACKGROUND AND AIMS

Worldwide, the prevalence of overweight and obesity has increased. We examined sex-specific patterns in the relationship of body mass index (BMI) with muscle strength and physical function among older Mexican Americans over time.

METHODS AND RESULTS

Participants (N = 1975) aged ≥65 years (mean = 72.4) were from a longitudinal study of Mexican American older adults (1993/94-2016). Measures collected at each interview included socio-demographics and health status; BMI (independent variable); short physical performance battery (SPPB) and handgrip strength (HGS) (outcomes). Participants were grouped into underweight (<18.5 kg/m); normal weight (18.5-24.9 kg/m); overweight (25-29.9 kg/m); class I obesity (30-34.9 kg/m); and class II/morbid obesity (≥35 kg/m). Changes in SPPB and HGS by BMI and sex over time were estimated using general linear mixed models. Males deemed overweight (β = 0.46; Standard Error [SE] = 0.11; p-value = 0.0001), class I obesity (β = 0.43; SE = 0.15; p-value = 0.0037), and class II/morbid obesity (β = 0.66; SE = 0.29; p-value = 0.0246) scored higher in SPPB than those with normal weight. Females deemed overweight (β = 0.49; SE = 0.10; p-value = 0.0001) and class I obesity (β = 0.32; SE = 0.11; p-value = 0.0047) scored higher on the SPPB than those with normal weight. Males and females deemed overweight (β = 0.56; SE = 0.29; p-value = 0.0535 and β = 0.65; SE = 0.18; p-value = 0.0003, respectively) and class I obesity (β = 1.08; SE = 0.39; p-value = 0.0062 and β = 0.92; SE = 0.22; p-value = 0.0001, respectively) scored higher in HGS than those with normal weight.

CONCLUSION

We found no sex differences in the trajectories of decline for HGS and physical function. Females and males classed as overweight or class I obesity experienced slower decline in HGS and physical function.