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Motor function decline from 65 years linked to mortality

By Nicole MacKee
Earlier detection of motor function decline in older adults could present opportunities for prevention and intervention, say researchers who have plotted a trajectory of functional decline in the decade before death.

In a prospective cohort study of more than 6000 participants in the UK, reported in the BMJ, motor function was assessed at age 65, 69, and 72 years.

Objective measures of walking speed, grip strength and timed chair rises, as well as self-reported measures of physical function and limitations in activities of daily living (ADL) were used to gauge motor function.

The researchers reported that poorer motor function at around 65 years was associated with increased mortality for walking speed (22% increased risk), grip strength (14%) and self-reported physical function (17%) over a mean of 10.6 years’ follow up. Self-reported ADL limitations were associated with a 30% increased risk of mortality.

Analysis of the trajectories of motor function decline before death showed that the earliest indicators were overall motor function – including timed chair rises (10 years before death) and self-reported physical function (seven years before death) – while ADL limitations emerged around four years before death.

Associate Professor David Scott, exercise scientist at the Institute for Physical Activity and Nutrition (IPAN), Deakin University, Melbourne, said this suggested that some measures may be better than others for early identification of older adults at risk of a terminal decline in physical function.

Professor Scott said ‘sarcopenia’ – the age-related decline in muscle mass and function, which was only recognised as a distinct disease entity five years ago – remained an underused indicator of overall health decline.

‘We do not currently have a consensus on a clinical definition of sarcopenia, although guidelines recommend assessment of many of the objective measures examined in this study (e.g. gait speed, hand grip strength and timed chair rises),’ he said.

‘This lack of consensus, together with poor health professional and public awareness, means these measures are not currently a part of standard care for most older adults.’

He said the Australian and New Zealand Society for Sarcopenia and Frailty Research was working to develop a clinical consensus on diagnosis and management of sarcopenia (https://anzssfr.org).

Professor Scott said exercise training, particularly progressive resistance exercise, was the most effective intervention to prevent and treat functional decline.

‘There is certainly opportunity for health professionals to play a greater role in assessing physical function in older adults and referring them to exercise physiologists for appropriate supervised exercise programs,’ he said, adding that dietitians could also advise on dietary requirements to minimise muscle mass declines in older adults.

‘Although some decline in muscle force-producing capacity is an inevitable part of ageing, early identification and intervention – primarily through resistance training – can reduce the likelihood and/or duration of time that functional declines significantly impact on physical and psychosocial health of older adults.’
BMJ 2021; 374: n1743; http:// dx.doi.org/10.1136/bmj.n1743.