- A new study found that people who were overweight in middle age had a greater risk of being pre-frail, or frail, 21 years later.
- This could potentially affect their quality of life as they age.
- Older adults who are frail are at a higher risk of falling and being injured, being hospitalized and experiencing complications as a result of that hospitalization.
Vulnerability in old age is sometimes thought of as weight loss — including muscle mass — as people age, but new research suggests that weight gain may also play a role in the development of this condition.
In the study, published Jan. 23 in the journal BMJ Open, researchers from Norway found that people who were overweight in middle age — as measured by body mass index (BMI), or waist circumference — had a greater risk of being pre-frail, or frail, 21 years later.
This could potentially affect their quality of life as they age.
“Frailty is a powerful barrier to aging successfully and on its own terms,” says Nikhil Satchidanand, PhD, an exercise physiologist and assistant professor at the University at Buffalo, who was not involved in the new study.
Older adults who are frail are at greater risk of falling and being injured, being hospitalized and experiencing complications as a result of that hospitalization, he said.
In addition, frail older adults are more likely to experience deterioration that results in a loss of independence and the need to enter a long-term care facility, he said.
The findings of the new study echo those of previous long-term studies that found an association between middle-aged obesity and pre-frailty/frailty in later life.
However, this is an observational study, so the researchers couldn’t prove direct cause and effect.
Researchers also tracked changes in the participants’ lifestyle, diet, habits and friendship networks during the study, all of which could have affected their risk of developing frailty.
But the authors write that the study’s results emphasize the “importance of routinely assessing and maintaining an optimal BMI and [waist circumference] throughout adulthood to reduce the risk of frailty in old age.”
The study was based on data from surveys of more than 4,500 residents of Tromsø, Norway, aged 45 or older, between 1994 and 2015.
Participants’ height and weight were measured in each survey. This was used to calculate BMI, a screening tool for weight categories that can lead to health problems. A higher BMI does not always indicate a higher body fat.
Some surveys also measured participants’ waist circumference; this is used to estimate belly fat.
In addition, researchers determined frailty based on the following criteria: unintentional weight loss; exhaustion; weak grip strength; low walking speed; and a low level of physical activity.
Vulnerability was characterized by the presence of at least three of those criteria, and pre-vulnerability by one or two of them.
Because only 1% of participants had frailty at the last follow-up visit, researchers grouped these people together with the 28% who had pre-frailty.
The analysis found that people who were obese in middle age, as indicated by a higher BMI, were nearly 2.5 times more likely to be pre-frail/frail 21 years later, compared to people with a normal BMI.
In addition, those with a moderately high or high waist circumference were up to twice as likely to be pre-frail/frail at the last follow-up visit than those with a normal waist.
Researchers also found that at the end of the study period, people were more likely to be pre-frail/frail if they had gained weight or if their waistline had increased during that time.
Satchidanand said the study provides additional evidence that early adoption of healthy lifestyle choices can help support successful aging.
“This study should remind us that the negative consequences of increasing obesity beginning in early adulthood are far-reaching,” he said, “and will have a significant impact on overall health, functional capacity and quality of life in old age. “
Dr. David Cutler, a family physician at Providence Saint John’s Health Center in Santa Monica, California, said a shortcoming of the study is that the researchers focused on the physical aspects of frailty.
In contrast, “most people in the general public would view frailty as impaired physical and cognitive functioning,” he said.
While the physical criteria used by the researchers in this study have been applied in other studies, some researchers have tried to account for other aspects of frailty, such as cognitive, social, and psychological dimensions.
In addition, Cutler said some of the frailty measures in the new study were self-reported by the participants — such as exhaustion, low physical activity and unintentional weight loss — meaning they may not be as accurate.
Another limitation Cutler pointed out is that some people dropped out of the study before the last follow-up visit. These people tended to be older, with higher levels of obesity and other risk factors for frailty, the researchers found.
However, when researchers excluded people who were older than 60 at the start of the study, the results were similar.
Despite the observational nature of the study, the researchers suggested several possible biological mechanisms for their findings.
Increased fat deposits can contribute to inflammation in the body, which is also associated with fragility. The deposition of fat in muscle fibers may also contribute to decreased muscle strength, they wrote.
Dr. Mir Ali, a bariatric surgeon and medical director of the MemorialCare Surgical Weight Loss Center at Orange Coast Medical Center in Fountain Valley, Calif., said obesity can affect functioning in later life in other ways.
“My obese patients often have more joint problems and more back problems,” he said. “This could affect their mobility and their ability to have a decent quality of life, including as they age.”
While frailty is partially related to aging, Satchidanand said it’s important to remember that not every older adult becomes frail.
In addition, “although the underlying mechanisms of vulnerability are very complex and multidimensional, we have some control over many of the factors that drive vulnerability,” he said.
Lifestyle choices such as regular exercise, reasonable diet, good sleep hygiene and stress management have been shown to influence weight gain in adulthood, he said.
However, Ali said that maintaining a healthy weight is sometimes complicated.
“There are a host of factors that contribute to obesity,” he said, including genetics, hormones, access to quality food and a person’s education, income and occupation.
While Cutler is concerned about the study’s limitations, he said the research shows that doctors, patients and society should be aware of the issue of vulnerability.
“We don’t really know what to do about vulnerability. We don’t necessarily know how to prevent it. But we have to be aware of it,” he said.
Satchidanand said greater awareness of vulnerability is especially important given the aging population.
“As our global society continues to age rapidly and our average life expectancy increases, we are faced with the need to better understand the underlying mechanisms that drive frailty,” he said, “and to develop effective and manageable strategies to both prevent and treat vulnerability syndrome.”