Higher BMI Associated With Increased Risk of CVD, Greater Proportion of Life Lived With CVD

Both overweight and obesity are associated with significantly increased risk for cardiovascular disease (CVD). According to a study published in JAMA Cardiology, obesity is also associated with shorter longevity and a greater proportion of life lived with CVD. While overweight was associated with similar longevity as normal weight, the overweight group has a greater proportion of life lived with CVD.

Over the past 3 decades, the prevalence of overweight and obesity in the United States has increased dramatically. “In recent years, controversy about the health implications of overweight status has grown, given findings of similar or lower all-cause mortality rates in overweight compared with normal weight groups,” wrote the authors of the study. According to the authors, current studies do not take into account the age at onset or the duration of CVD, which limits the ability to determine the proportion of life spent with CVD.

“This is especially important because disease burden associated with development of CVD results in less healthful years of life, poorer quality of life, and increased health expenditures,” wrote the authors.

The authors used pooled individual-level data from 190,672 adults (baseline age, 20-39, 40-59, 60-79) from 10 large US prospective cohorts, with 3.2 million person-years of follow-up from 1964 to 2015. Participants did not have clinical CVD at baseline and had available BMI index and CVD outcomes data. Data were analyzed from October 2016 to July 2017.

Overweight middle-aged men and women (age 40-59) had a higher cumulative lifetime risk of incident CVD events and CVD death compared to those with a normal BMI of 18.5-24.9. Results were similar for older adults (age 60-79). For young men and women (age 20-39), results were similar for the obese group, with an increased lifetime risk of incident CVD events, but not for the overweight group.

Incident CVD events occurred in more middle-aged men and women in overweight (37% and 28%, respectively), obese (47% and 39%) and morbidly obese (65% and 48%) groups compared with those in the normal BMI group (32% and 22%). Adjusted for competing hazard ratios, middle-aged men and women in the overweight, obese, and morbidly obese groups had significantly higher hazard ratios, ranging from 1.21 to 3.14.

Overall survival time was significantly shorter for middle-aged men who were obese (27.2 years) and morbidly obese (23.4 years) than for men who had normal BMI (29.1 years) and men who were overweight (29.3 years). For middle-aged women, overall survival was 33.2 years for those with normal BMI, 31.8 years for those who were overweight, 29.8 years for those who were obese, and 27.2 for those who were morbidly obese.

Average years lived with CVD were longer for middle-aged adults in the overweight and obese groups compared with those in the normal BMI group. Similar results were shown for younger and older results.

“Our results provide critical perspective on the cardiovascular disease burden associated with overweight, highlight unhealthy years lived with increased cardiovascular morbidity, and challenge the prevalent view that overweight is associated with greater longevity compared with normal BMI,” concluded the authors. “Overweight does not appear to be associated with significantly greater longevity, and there is a greater burden of CVD during that lifespan.”

Reference:

Khan S, Ning H, Wilkins J, et al. Association of body mass index with lifetime risk of cardiovascular disease and compression of morbidity. [Published online February 28, 2018]. JAMA Cardiol. doi:10.1001/jamacardio.2018.0022.