Swings in metabolic measures linked to cardiovascular events
Metabolic parameters like body weight, blood pressure, cholesterol and blood sugar levels are established risk factors for cardiovascular disease. But a new study suggests it’s not just abnormal measures of these components that portend risk—significant fluctuations in these areas are independently linked to all-cause mortality, heart attack and stroke among otherwise healthy people.
Using the Korean National Health Insurance System, researchers identified 6.7 million people who didn’t have diabetes, hypertension or dyslipidemia and underwent at least three health examinations from 2005 to 2012. Those patients were then followed through the end of 2015 for a median follow-up period of 5.5 years.
Compared to people with stable measurements throughout the study, those in the top quartile of variability for all four factors were at increased risks of 127 percent for all-cause mortality, 43 percent for myocardial infarction and 41 percent for stroke after multivariable adjustment. The researchers noted high variability was predictive of the adverse outcomes regardless of whether a change of more than 5 percent was tied to an improved or worsened reading.
“Our results add evidence that high variability in metabolic parameters is associated with adverse health outcomes not only in diseased populations but also in relatively healthy populations, although the mechanism could be somewhat different,” wrote senior author Seung-Hwan Lee, MD, PhD, with the Catholic University of South Korea, and colleagues. They published their study Oct. 1 in Circulation.
“These findings suggest that variability in metabolic parameters may be a prognostic surrogate marker for predicting mortality and cardiovascular outcomes.”
When looked at individually, swings in cholesterol and body weight were associated with the most heightened risk of all-cause mortality. Individuals displaying fluctuations in the top 25 percent of those measures showed risk increases of 31 percent and 53 percent, respectively, when compared to those in the lowest quartile of variability. Large vacillations in systolic blood pressure were linked to 14 percent increased odds of stroke, tying body weight changes for the largest risk increase for that particular outcome.
“The risks of all-cause mortality, MI and stroke increased with an increasing number of high-variability parameters, which suggests that the associations of variability of each parameter with the cardiovascular outcomes were additive,” the authors wrote. “Treatment strategies to reduce fluctuations in metabolic parameters should be another goal to prevent adverse health outcomes.”
Lee et al. acknowledged they couldn’t prove cause-and-effect due to the observational nature of the study. Also, the study population was based in Korea, making it uncertain whether the findings would be similar in the U.S. or other countries.
“However, several previous studies on variability were performed in other populations, suggesting that it is likely to be a common phenomenon,” Lee said in a press release.
Daniel joined TriMed’s Chicago editorial team in 2017 as a Cardiovascular Business writer. He previously worked as a writer for daily newspapers in North Dakota and Indiana.