Nearly a third of middle-aged workers suffer from some level of frailty, including fatigue, issues with walking and other physical limitations that make them less able to hold a job, according to a UK study.
Frailty is more often something considered when treating elderly patients, but middle-aged patients may face some of the same symptoms, the study team said.
"Lots of factors are encouraging people to work longer, but this may not be feasible for those with major health problems and, depending on circumstances, might be either good or bad for health," lead author Keith Palmer of the University of Southampton said.
Lots of factors are encouraging people to work longer, but this may not be feasible for those with major health problems and might be either good or bad for health
To examine the link between frailty and employment, researchers recruited more than 8,000 people in their 50s and early 60s from 24 English general practices.
In particular, the respondents answered questions about five measures of frailty. These included unintentional weight loss of more than 10 pounds over the past year, physical exhaustion during the past week and slow walking speed or inability to walk.
The measures also included physical activity levels - whether respondents worked up a sweat during exercise in an average week - and weakness of grip, assessed by the ability to open jars.
Overall, the researchers classified 4% of participants as frail, based on having three to five of the frailty symptoms, while nearly a third of participants were considered "pre-frail" because they reported one or two of the frailty symptoms.
Frailty was tied to a large impact on employment. Three-quarters of frail people were not working at all and 60% had left their last job on health grounds. Compared with non-frail people, frail people were 30 times more likely to lose their jobs.
Frail people were nearly 11 times more likely to have been out of work on prolonged sick leave in the past year, compared with healthy workers. Frail workers were also over 17 times more likely to report needing to cut down a lot on work in the past year, compared with non-frail workers.
Workers considered to be frail were nearly 15 times more likely to have difficulty coping with physical demands at work and to be unsure if they would be able to continue work in two years.
The pre-frail workers were also at higher risk of bad outcomes compared to healthy counterparts, but their risk was not as extreme as that of frail people.
Frailty had the biggest impact on blue collar manual workers rather than office workers, although the office workers still saw a significant effect, researchers noted.
"Older workers are more likely to be physically vulnerable than younger workers," Lucie Kalousova, a researcher at the University of Michigan in Ann Arbor who studies frailty among workers, said.
Despite this, frailty is preventable and can be reversed, Ms Kalousova, who was not involved in the study, said. "Though medical science is not yet fully clear on the best ways to prevent frailty, it may be delayed or forestalled by regular exercise and a nutritious diet," she said.
Although it is difficult to pinpoint the causes of frailty, research showed that for elderly people, exercise programs focused on balance and strength and attention to diet can improve health outcomes, Dr Palmer noted.
"It is too early to say precisely what is needed in mid-life to prevent frailty, but a reasonable bet is some combination of exercise (to maintain muscle strength and balance) allied with a suitable diet," Dr Palmer said.