Type 2 diabetes (T2D) has been proven to raise the risk of cardiovascular complications, but a diagnosis doesn’t necessarily signal an inevitable slide toward those outcomes, according to the authors of a new study in the Journal of the American College of Cardiology.
Healthy lifestyle factors—consuming a high-quality diet, not smoking, exercising regularly and drinking alcohol in moderation—were associated with significantly reduced risks of cardiovascular events and mortality, even when patients waited until a diabetes diagnosis to shape up.
In fact, for each additional low-risk behavior patients practiced post-diabetes versus pre-diabetes, their overall risk of cardiovascular disease (CVD) was cut by 14 percent. This included a 12 percent lower risk of coronary heart disease, a 21 percent lower risk of stroke and a 27 percent lower risk of CVD mortality over the average 13.3 years of follow-up.
“Adherence to a healthy diet and lifestyle and correction of past risk-prone behavior are associated with substantially lower risks of CVD and related mortality among patients with T2D,” wrote lead researcher Gang Liu, PhD, with the department of nutrition at the Harvard T.H. Chan School of Public Health, and colleagues. “Further research is needed to identify the most effective strategies to encourage patients with diabetes to adopt and maintain a healthy lifestyle.”
The researchers analyzed 11,527 volunteers from two different studies of healthcare professionals who were diagnosed with T2D during follow-up but didn’t have CVD or cancer at the time of diabetes diagnosis. The pooled cohort contained 8,970 women and 2,557 men who self-reported their lifestyle behaviors every two to four years.
Each patient was rated on a scale of 0 to 4 based on how many low-risk behaviors they followed. These included a healthy diet (top 40 percent of the Alternative Healthy Eating Index), nonsmoking, moderate to vigorous physical activity for at least 2.5 hours per week and moderate alcohol consumption (one standard drink per day or fewer for women; two drinks per day or fewer for men).
Compared to participants practicing none of these behaviors, those following three or more demonstrated lower incidences of CVD (52 percent reduction), coronary heart disease (47 percent), stroke (67 percent) and cardiovascular mortality (68 percent). These calculations were adjusted for multiple patient variables.
“In the current study, we addressed a few major limitations in previous studies by using repeated assessments (every 2 to 4 years) of dietary and lifestyle factors to capture potential variations of lifestyle practices, examining both CHD and stroke incidence and CVD mortality, and evaluating associations of an overall healthy lifestyle,” the authors wrote. “Moreover, we further illustrated that improvements in lifestyle behavior from pre-diabetes to post-diabetes diagnosis were also associated with a significantly lower risk of subsequent CVD events.”
Liu et al. noted these lifestyle modifications are “affordable and effective” methods to prevent these complications, which have reached epidemic proportions as the rates of diabetes and obesity have risen.
Importantly, all the study participants were health professionals and most were white, therefore limiting generalizability to other groups. The study was also limited by its observational design and the authors acknowledged other lifestyle behaviors could have been assessed and deemed important for CVD prevention.
In an accompanying editorial, three researchers pointed out each low-risk factor was preventive against CVD or mortality but there was also a “synergistic effect” when multiple healthy behaviors were combined.
But because the study contained healthcare professionals with relatively high socioeconomic status, they said evaluating these factors in other populations is necessary to see if they are as easily adopted and equally beneficial. Healthcare professionals—especially those volunteering for a study—may be more likely than the average person to follow guideline-recommended therapies, the editorialists noted.
Kim Connelly, MBBS, PhD, and coauthors said other questions must still be addressed including identifying which diets are the best, what amount of alcohol can be deemed “safe” for diabetic patients and whether there is a minimum or maximum amount of exercise that should be recommended.
“As practitioners managing patients with T2D, we need to send a clear message that health care promotion, advocacy, and research should continue to focus on these healthy lifestyle factors not only to improve glycemic control, but to reduce overall cardiovascular risk,” they wrote. “As society continues to evolve and becomes increasingly complex, it is important that we do not overlook the so-called simple and fundamental aspects of patient care and always return ‘back to basics.’”