Obesity could reduce life expectancy by up to 8 years and healthy years of life by up to 19 years due to the effects oftype 2 diabetes and cardiovascular disease, according to research published in The Lancet Diabetes & Endocrinology.

“Not only is excess body weight associated with a significant reduction in life expectancy but an even greater reduction in healthy life-years,” Steven A. Grover, MD, of the Research Institute of the McGill University Health Centre, Montreal, told Endocrine Today. “Living without [CVD] or diabetes is something worth working toward.”

Steven A. Grover

Grover and colleagues developed and validated a disease-simulation model to determine the years of life and healthy life-years lost due to diabetes and CVDassociated with excess body weight. The model estimated annual risk for diabetes, CVD and mortality in three categories of BMI — 25 kg/m² to <30 kg/m² (overweight); 30 kg/m² to <35 kg/m² (obese); ≥35 kg/m² (very obese) — compared with an ideal BMI of 18.5 kg/m² to <25 kg/m².

The researchers used data from 3,992 non-Hispanic white participants involved in the National Health and Nutrition Examination Survey (2003-2010) with available complete risk factor data and fasting glucose concentrations.

Excess body weight was positively linked to risk factors for CVD and type 2 diabetes. The effect of excess weight on years of life lost was most pronounced for young adults and diminished with increasing age.

“While losing weight or exercising regularly is not easy for many of us, the potential benefits are huge,” Grover said. “A modest reduction in weight of approximately 10 lb and as little as 30 minutes of daily physical activity most days of the week have been proven to reduce the risk of developing diabetes by as much as 60%. The potential benefits in preventing a heart attack or stroke are also substantial.”

For men with obesity, the years of life lost ranged from 0.8 in those aged 60 to 79 years (95% CI, 0.2-1.4) to 5.9 years in those aged 20 to 39 years (95% CI, 4.4-7.4). For very obese men, years lost ranged from 0.9 in those aged 60 to 79 years (95% CI, 0-1.8) to 8.4 years in those aged 20 to 39 years (95% CI; 7-9.8). Smaller, and sometimes negligible, losses were seen in men with overweight.

Women in the very obese category showed similar results, with 6.1 years lost for those aged 20 to 39 years (95% CI, 4.6-7.6) and 0.9 years lost for those aged 60 to 79 years (95% CI, 0.1-1.7).

Healthy life-years lost overall were two to four times greater than years of life lost across all age groups and body weight categories. Young adults who were very obese, again, showed a greater reduction in healthy-life years, with men losing 18.8 years (95% CI, 16.8-20.8) and women 19.1 years (95% CI, 16.7-21.5).

“Appreciating the impact excess pounds have on our life expectancy and healthy years of life will hopefully provide health professionals with a new diagnostic measurement to motivate some individuals to make healthy changes to their lifestyle,” Grover said.

An attached commentary by Edward Gregg, PhD, of the division of diabetes translation at the CDC, underscored the researchers’ call for “meaningful metrics for education, counseling and health promotion” and noted that clinical utility of the estimates and their ability to distinguish the effects of small differences between obesity thresholds requires additional work.

Edward Gregg

However, Gregg called the efforts to refine estimation of the lifelong effect of obesity and diabetes important, with populations poised to live longer with chronic diseases and have diverse responses to interventions.

“This heterogeneity might place a higher premium on decision-making methods that can simultaneously take a life course perspective, incorporate interventions, and consider individual differences,” Gregg wrote, “so that clinicians and public health leaders alike can effectively tackle the next phases of the obesity and diabetes epidemics.” – by Allegra Tiver