Weight swings risky for heart patients

Losing and regaining weight repeatedly may be dangerous for overweight heart patients, a study suggests.

Heart attacks, strokes and death were more common in patients whose weight changed the most over four years.

For some, weight changes might have reflected yo-yo dieting, which some previous studies have suggested may be unhealthy for people without heart problems. That means a hefty but stable weight might be healthier than losing but repeatedly regaining extra pounds.

But big weight fluctuations in heart patients studied could also have been unintentional and a possible sign of serious illness that would explain the results, the researchers and outside experts said.

Doctors not involved in the study called it interesting but not proof that "yo-yo" weight changes are risky for overweight heart patients.

Regardless, the recommendation from New York University cardiologist and lead author, Dr Sripal Bangalore, echoes standard advice for anyone who's overweight: "Lose weight but try to keep that weight off."

The study was published Wednesday in the New England Journal of Medicine. It's an analysis of about 9500 patients involved in a different study that didn't examine reasons for weight changes. Weight was measured an average of 12 times over four years and some patients lost and regained several pounds in between each measurement.

Among the 1900 patients with the biggest weight changes, 37 per cent had fatal or non-fatal heart attacks, strokes or other heart trouble during the study. That compared with 22 per cent of the 1900 patients whose weight changed the least.

Dr Clyde Yancy, cardiology chief at Northwestern University's medical school in Chicago, said there's no clear biological explanation for how yo-yoing weight might cause harm and that the study results could be merely due to chance.

"The takeaway? Simple messages still prevail," Yancy said.

"A heart-healthy lifestyle both prevents and treats cardiovascular disease."