Couples share heart disease risk factors and behaviors

Risk factors for heart health, such as smoking, unhealthy diets and minimal physical activity, may seem personal, but for people who are married or in a domestic partnership, the behavior patterns of one person may be strongly linked to the patterns of the other.

A new study led by investigators from Harvard-affiliated Brigham and Women’s Hospital assessed cardiovascular risk factors and behaviors of more than 5,000 couples who took part in an employee wellness program offered by Quest Diagnostics. The team used several metrics to classify people as having ideal or non-ideal risk factors and behaviors, finding that in 79 percent of couples, both people fell into the non-ideal category for cardiovascular health, with most sharing unhealthy diets and getting inadequate exercise. The findings point out the potential importance of addressing healthy behaviors for both people in a relationship. Results are published in JAMA Network Open.

“We know a lot about cardiovascular risk factors for individuals but not for couples,” said corresponding author Samia Mora of the Brigham Divisions of Preventive Medicine and Cardiovascular Medicine. “We expected to see some shared risk factors, but it was a surprise to see that the vast majority of couples were in a non-ideal category for overall cardiovascular health.”

Mora and colleagues examined data from Quest Diagnostics, which offered a voluntary health assessment program to its employees. Researchers analyzed data from 5,364 couples (10,728 individuals) who joined the program between October 2014 and August 2015. The researchers determined whether each individual was in the ideal, intermediate, or poor category for each of the American Heart Association-defined Life’s Simple 7 (LS7) risk factors and behaviors. The LS7 include smoking status, body mass index, physical activity, healthy diet score, total cholesterol, blood pressure and fasting glucose. The team also gave each participant an overall cardiovascular (CV) health score. Data were collected from questionnaires, examinations and laboratory tests.

When examined individually, more than half of the participants were in the ideal category for three LS7 risk factors and behaviors: smoking status (never smoked), total cholesterol (<200 mg/dL), and fasting glucose (<100 mg/dL, Table 2). But more than a quarter of the individuals were in the poor categories for BMI, physical activity, and CV health score. Only 12 percent of individuals were in the ideal category for CV health score.

When both people in the couple were considered together, more than half of couples shared all LS7 risk factors and behaviors as well as CV health score. When one member of a couple was in the ideal category, the second member was more likely to be in the ideal category for all factors except for total cholesterol. But 79 percent of couples were both in the non-ideal category for CV health score, largely driven by unhealthy diet and inadequate exercise.

The team did find that when one partner had quit smoking, lost weight, increased their physical activity or improved their diet, the other partner was more likely to have done so. But over the five-year study period, the health of couples, risk factors and behavior patterns remained relatively unchanged overall. Apart from modest changes in blood pressure and fasting glucose, the team found no significant changes in factors.

The authors note that some of the data in the study comes from self-reporting, which can be inaccurate, and that the longest duration for follow up was five years. The study only examined data for employees who chose to participate in the company’s wellness program, but it was a diverse population. The team found some variation by ethnicity, socioeconomic status, and geographic location.

“Our data suggest that risk factors and behaviors track together for couples,” said Mora, who is an associate professor of medicine at Harvard Medical School. “Rather than thinking about interventions for individuals, it may be helpful to think about interventions for couples or whole families. And it’s important for people to think about how their health and behaviors may influence the health of the person(s) they are living with. Improving our own health may help others.”

Mora has served as a consultant for Quest Diagnostics for work outside the current study. Four co-authors are employees of Quest Diagnostics.