Long term determinants of functional decline of mobility: an 11-year follow-up of 5464 adults of late middle aged and elderly.

This confirmatory study aims at investigating the long term determinants of mobility limitation among late middle aged and elderly in a physically less active population. Five thousand four hundred and sixty-four participants aged 50-97 in 1996 enrolled the Taiwan Longitudinal Study on Aging (TLSA) for four waves of interview during 11 years. Social and health-related determinants were collected in each interview. Mobility limitation was enquired level of difficulty in eight movement tasks, including lifting 11kg weight, squatting, running 20-30m, standing for 15min, walking 200-300m, climbing up two to three floors, raising arms up and grasping with fingers. According to the mixed models with repeated measurements, more frequent gardening and longer time for each exercise predicted subsequent better mobility function in Taiwanese elderly while controlling demographics and current comorbidities. The protective effect of gardening was robust in all models. Frequent alcohol consumption was harmful to future mobility function, but less as harmful when participants aged. Besides, the depression-related somatic complaints were predictive to future mobility limitation among those without limitation at baseline. It shall be worthy to explore the dosage as well as the mechanism of these protective factors, especially the most significant but the least explored factor, gardening. Additionally, efforts should be made to understand the relationship between depression-related somatic complaints and mobility decline and so as the relevant interventions.