Yo-Yo a No-No: Fluctuating Body Weight May Increase Morbidity and Mortality Among CAD Patients

In patients with existing CAD, repeatedly losing and gaining weight is associated with an increased likelihood of cardiovascular events and mortality compared with maintaining a stable weight over time, new research shows. The effect was most pronounced in patients with large fluctuations in their weight, who had an MI risk more than double that of subjects who maintained a stable weight.

Weight cycling is a common occurrence in clinical practice after physicians recommend to their overweight or obese patients to lose some weight, noted the study’s lead author Sripal Bangalore, MD, MHA (New York University School of Medicine, New York, NY).

“The way I see it, our results may be a motivational factor to not only lose weight, but to try to maintain any weight loss that the patient experiences,” he added. While many patients likely know that their weight has its ups and downs, others may not notice. In either case, a short discussion about any weight changes is important in routine patient care, Bangalore said.

Commenting on the study, Andrew M. Freeman, MD (National Jewish Health, Denver, CO), who co-chairs the American College of Cardiology’s nutrition and lifestyle working group, told TCTMD that it also raises important issues about nutrition shortfalls on the part of both patients and their physicians that may be more harmful than previously thought.

“We all know people who follow a fad diet of one sort or another and go up and down, up and down, and from this study and others it appears that doing so is not a healthful approach,” he said. “The vast majority of physicians in this country have limited nutritional training, so it behooves us to get more [education] in the nutrition field so that we can counsel our patients appropriately. Telling patients to lose weight without tangibles or practicals is not enough support to help effect a behavioral change. A patient-centric approach is the best way to achieve the maintaining of weight loss and the change in behavior. My recommendation is that we need to weave some degree of lifestyle medicine into every single visit, so that the message is continually reinforced.”

More Fluctuations Equal More Risk

The new study, published the April 6, 2017, issue of the New England Journal of Medicine, was a post-hoc analysis of the international, atorvastatin-focused Treating to New Targets trial, and included 9,509 CAD patients who had their weight recorded approximately one dozen times over an average of about 5 years. Although lifestyle changes were recommended, specific information about how patients were counseled to lose weight was unavailable.

Bangalore and colleagues found that compared with patients who kept their weight relatively stable, those with fluctuations had a higher risk of any coronary or cardiovascular event, as well increased mortality. Patients with the most variations in their weight–in the ballpark of around 8.5 pounds—had a 64% higher risk of a coronary event compared with those with fluctuations of around 2 pounds. Those with the greatest instability in weight also had: an 85% higher risk of a cardiovascular event, a 117% higher risk of MI, a 136% higher risk of stroke, and a 124% greater mortality risk. Compared with patients maintaining a steady weight, those who did not also had a higher likelihood of developing new-onset diabetes (HR 1.08; 95% CI 1.02-1.14).

As for why weight fluctuation might be harmful, Bangalore said studies of patients who have had very large weight gains or losses in a short period of time indicate that this so-called yo-yoing acts as a stressor that may contribute to numerous neurohormonal changes, including insulin resistance.

“Even though the weight fluctuations we saw in our study were relatively small, in a high-risk patient these hormonal changes may explain some of the increased risk we are seeing,” Bangalore said.

 Sustain and Maintain Is the Goal

“It’s hard to make a firm conclusion, because it’s a bit of a narrow subset and it is difficult to fully characterize weight cycling,” Freeman observed. “But there have been a few studies over the years that have shown that people who yo-yo in their weight seem to have worse cardiovascular outcomes, although the mechanisms behind it are not clearly elucidated.”

Freeman pointed to one study of postmenopausal women, presented at the American Heart Association Scientific Session last year, which found that the risk of sudden cardiac death was 3.5 times higher among women who were normal weight but who lost and regained weight over the 11-year follow up of the study versus maintaining their weight.

For Freeman, the important message to impart to patients who need to lose weight is to find something that will be sustainable for them over time. As for clinicians who notice that their patients are yo-yoing, “clearly they haven’t found the path of maintenance and sustaining, and that’s a warning sign for you to do better in how you approach that patient,” he said.