Declining weight during ageing linked to cognitive impairment

People having a greater weight loss during ageing are at an increased risk of mild cognitive impairment (MCI) which affects the memory, language, thinking and judging capacity of an individual, says a new study.

MCI, which is an early stage of dementia -- a general term for a decline in mental ability -- can be seen in people with increasing weight loss per decade as they age from midlife to old age, the study said, adding that about 5 percent to 15 percent of people suffering from MCI are progressing towards dementia each year.

The researchers noted that people who developed MCI had a greater average weight change per decade from midlife than those who remained cognitively normal.

A greater decline in weight per decade was associated with an increased risk of incident MCI, with a weight loss of 5 kilograms per decade corresponding to a 24 percent increased risk of MCI, the findings, published online in the journal JAMA Neurology, showed.

"In summary, our findings suggest that an increasing rate of weight loss from midlife to late life is a marker for MCI and may help identify persons at increased risk of MCI," said Rosebud O. Roberts from the Mayo Clinic in Minnesota, US.

The researchers studied participants 70 or older from the Mayo Clinic Study of Aging, which started in 2004. Height and weight in midlife (40 to 65 years old) were collected from medical records.

During an average of 4.4 years of follow-up, the authors identified 524 of 1,895 cognitively normal participants who developed MCI (about 50 percent were men and their average age was 78.5 years).

Those who developed MCI were older and more likely to have diabetes, hypertension, stroke or coronary artery disease compared with study participants who remained cognitively normal.