The content of this website is intended for healthcare professionals only

Obesity associated with worse mortality and higher CVD risk

Overweight people have no shorter lives than those of healthy weight – but do get CVD younger

Louise Prime

Thursday, 01 March 2018

People who are obese are more likely to die younger, and to have a higher risk of illness and death from cardiovascular disease (CVD), than people of normal weight, research has shown. The large observational study*, published in JAMA Cardiology, also found that overweight people have a higher risk of developing CVD at a younger age – but have a similar lifespan to those of a healthy weight.

The research team, from Chicago and Dallas in the US, pointed out that although previous studies have demonstrated lower all-cause mortality in people who are overweight compared with those of normal body mass index (BMI), they have not considered the proportion of life lived with cardiovascular disease (CVD) morbidity in individuals who are overweight and obese compared with normal weight. So, they designed a population-based study to enable them to calculate lifetime risk estimates of incident CVD and subtypes of CVD, and to estimate years lived with and without CVD by weight status.

They used pooled individual-level data from adults (baseline age, 20-39, 40-59, and 60-79 years) across 10 large US prospective cohorts, with 3.2 million person-years of follow-up from 1964 to 2015. All participants were free of clinical CVD at baseline, with available data on BMI and CVD outcomes.

They reported that compared with people with a normal BMI (defined as 18.5-24.9kg/m2), lifetime risks for incident CVD were higher in middle-aged adults in the overweight and obese groups. Compared with normal weight, among middle-aged people, competing hazard ratios for incident CVD were 1.21 for overweight men and 1.32 for overweight women (BMI 25.0-29.9); 1.67 and 1.85 for obese men and women (BMI 30.0-39.9); and 3.14 and 2.53 for morbidly obese men and women (BMI ≥40.0). They added that higher BMI had the strongest association with incident heart failure among CVD subtypes.

Furthermore, the average number of years lived with CVD was longer for middle-aged adults in the overweight and obese groups compared with adults in the normal BMI group. Similar patterns were observed in younger and older adults.

The study authors concluded: “Our results provide critical perspective on the cardiovascular disease burden associated with being 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. Overweight does not appear to be associated with significantly greater longevity, and there is greater burden of CVD during that lifespan.”

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

Registered in England and Wales. Reg No. 2530185. c/o Wilmington plc, 5th Floor, 10 Whitechapel High Street, London E1 8QS. Reg No. 30158470