Late-life weight gain boosts disability risk

NEW YORK (Reuters Health) - Gaining weight after age 50 increases a person's risk of becoming disabled, especially if he or she is already obese, new research from Italy shows.

The findings "emphasize the importance of preventing and treating obesity in older adults for the preservation of functional ability and independence," Dr. Luca Busetto of the University of Padova and colleagues conclude in the June issue of the Journal of the American Geriatrics Society.

While there is strong evidence that being obese in old age is associated with a greater likelihood of being disabled and speedier age-related decline, less is known about how weight gain or loss in older people affects their ability to function, Busetto and his team say.

To investigate, they looked at 2,910 men and women 65 or older, all of whom had reported how much they weighed at age 50 (but not whether or not they were disabled at this age). The researchers defined disability as having difficulty performing at least one activity of daily living, such as showering or dressing oneself.

Between age 50 and the time they entered the study, 30.6 percent of the men and 38.7 percent of the women gained more than 10 percent of their original body weight.

For people with a normal body mass index (BMI) at age 50, those who gained 5 percent to 10 percent of their original weight were 1.46 times more likely to be disabled when they entered the study, while people who gained more than 10 percent of their initial weight were at 1.61 times greater risk.

Among individuals who were obese at 50, gaining 5 percent to 10 percent of their original weight increased later disability risk 1.65-fold, while those who put on more than 10 percent were 2.59 times more likely to be disabled.

The researchers also found a greater risk of disability among originally normal-weight people who lost more than 10 percent of their body weight, but chronic illness accounted for most of this relationship. Obese individuals who lost this much weight were not more prone to being disabled later on, which "provides evidence that intentional weight loss can be safely recommended in overweight and obese older people," Busetto and colleagues conclude.

SOURCE: Journal of the American Geriatrics Society, June 2009.