Yo-yo dieting hikes death, heart and diabetes risks

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FocusYoYoAmong people with coronary artery disease, fluctuation in body weight was associated with double the mortality and a double rate of cardiovascular events independent of traditional cardiovascular risk factors. The risk of developing diabetes grows by 78%, found the large Lipitor study.

The findings, which need to be confirmed by further research, suggest a life-and-death conundrum. Being overweight is already known to pose serious health risks. The new research says dropping the pounds and putting them back on again poses additional dangers.

If you are an overweight person with heart disease who lost 20 pounds “you are worse off if you drop your weight and gain it back” than if you didn’t lose it in the first place, chief author Dr Sripal Bangalore, an interventional cardiologist and associate professor of medicine at New York University’s Langone Medical Centre is quoted in the report as saying.

The study is saying, “If you’re going to lose weight, do it right and you need to take it seriously,” said Dr Ira Ockene, a professor of medicine at the University of Massachusetts Medical School in Worcester, who was not connected with the research. But, she says, if people use the results as an excuse not to drop unhealthy pounds, “that would be unfortunate”. “There’s a lot of data that says if you lose weight and keep it off, you do better.”

“Hopefully this will be used as a motivation to lose weight and maintain weight,” Bangalore said.

Such yo-yo dieting, where a person’s weight fluctuates repeatedly, is already known to be unhealthy in people without heart disease. The new study explored whether that was specifically true for people with coronary artery disease, where fatty deposits have built up in the blood vessels feeding the heart muscle. The researchers recycled data from 9,509 volunteers who were part of a Lipitor study published in 2005 and sponsored by Pfizer. Another important limitation of the study: It did not examine whether patients lost weight because they tried to, or if their weight fluctuated because they were battling illness.

After adjusting for various factors such as high blood pressure, smoking, race, gender, diabetes, cholesterol levels and treatment with Lipitor, the Bangalore team found that people whose weights fluctuated the most were 2.24 times more likely to die from any cause within about five years, 2.17 times more likely to have a heart attack and 2.36 times more likely to be hit with a stroke than people whose weights were the most stable.

For every 3- or 4-pound change in body weight, their risk of heart attack, cardiac arrest, chest pain, death from heart disease or the need for surgery to open a clogged artery rose by 4%. The dangers posed by shifting weight were least pronounced in people who had a normal weight to begin with.

Ockene said people need to put weight loss in perspective. “Studies show people set unattainable goals. Heavy people say, ‘I need to lose 40 pounds’ and they set a goal that is largely unattainable. And when they lose 10 pounds they’re disappointed. And they say, ‘What the hell’ and they just gain it back,” he said.

“But if you lose 10 pounds and keep it off, your diabetes will be better, your blood pressure will be better, your lipids will be better, a lot of things will be better. You don’t need to lose 30 or 40 pounds,” he said. “That’s an important issue for people to understand.”

Abstract
Background: Body-weight fluctuation is a risk factor for death and coronary events in patients without cardiovascular disease. It is not known whether variability in body weight affects outcomes in patients with coronary artery disease.
Methods: We determined intraindividual fluctuations in body weight from baseline weight and follow-up visits and performed a post hoc analysis of the Treating to New Targets trial, which involved assessment of the efficacy and safety of lowering low-density lipoprotein cholesterol levels with atorvastatin. The primary outcome was any coronary event (a composite of death from coronary heart disease, nonfatal myocardial infarction, resuscitated cardiac arrest, revascularization, or angina). Secondary outcomes were any cardiovascular event (a composite of any coronary event, a cerebrovascular event, peripheral vascular disease, or heart failure), death, myocardial infarction, or stroke.
Results: Among 9509 participants, after adjustment for risk factors, baseline lipid levels, mean body weight, and weight change, each increase of 1 SD in body-weight variability (measured according to average successive variability and used as a time-dependent covariate) was associated with an increase in the risk of any coronary event (2091 events; hazard ratio, 1.04; 95% confidence interval [CI], 1.01 to 1.07; P=0.01), any cardiovascular event (2727 events; hazard ratio, 1.04; 95% CI, 1.02 to 1.07; P<0.001), and death (487 events; hazard ratio,1.09; 95% CI, 1.07 to 1.12; P<0.001). Among patients in the quintile with the highest variation in body weight, the risk of a coronary event was 64% higher, the risk of a cardiovascular event 85% higher, death 124% higher, myocardial infarction 117% higher, and stroke 136% higher than it was among those in the quintile with the lowest variation in body weight in adjusted models.
Conclusions: Among participants with coronary artery disease, fluctuation in body weight was associated with higher mortality and a higher rate of cardiovascular events independent of traditional cardiovascular risk factors.

Authors
Sripal Bangalore, Rana Fayyad, Rachel Laskey, David A DeMicco, Franz H Messerli, David D Waters

Reuters Health report
New England Journal of Medicine abstract
Related: Yo-yo dieting and heart risk in post-menopausal women


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