Dynapenic abdominal obesity and the effect on long-term gait speed and falls in older adults

Although both dynapenia and abdominal obesity have negative impact on physical function and health, few prospective studies evaluate the association of dynapenic abdominal obesity (D/AO) with gait speed and falls. Our aim was to examine the combined effect of low muscle strength and abdominal obesity on long-term gait speed and falls in older adults.

We used longitudinal data from the English Longitudinal Study of Ageing (ELSA), including 4987 individuals aged 60 years and over. Grip strength and waist circumference were measured at baseline. Gait speed and fall events (falls, recurrent falls, and fall-related injury) were evaluated during a 14-year follow-up. The study population were divided into nondynapenic nonabdominal obesity (ND/NAO), nondynapenic abdominal obesity (ND/AO), dynapenic nonabdominal obesity (D/NAO), and D/AO, according to the sex-specific grip strength (<16 kg for women and <26 kg for men) and waist circumference (>88 cm for women and >102 cm for men). We used generalized estimating equation (GEE) model with gait speed as the outcome and cox proportional hazards models with fall events as the outcome.

GEE model showed that gait speed decreased during the 14-year follow-up in all groups (all P_time < 0.001). Participants with ND/AO, D/NAO, and D/AO at baseline exhibited a worse gait speed than those with ND/NAO (all P_group < 0.001). No significant difference in the rate of gait speed decline between four groups was found (P_group×time = 0.062). Cox regression analysis showed that D/NAO and D/AO highly predicted falls, and the hazard ratio (HR) was 1.181 (95% CI: 1.002, 1.392) for D/NAO and 1.195 (95% CI: 1.006, 1.421) for D/AO. D/AO was the unique condition associated with recurrent falls and fall-related injury, and the HRs were 1.276 (95% CI: 1.018, 1.599) and 1.348 (95% CI: 1.066, 1.704), respectively.

Dynapenia abdominal obesity, determined by low grip strength and high waist circumference, exhibits worse gait speed and increases the risk of fall events in older adults. Effort to maintain the mobility should focus on improving muscle strength and reducing excess body fat.