Obesity May Add Decades of Diabetes and CVD, Shorten Life
Very obese young men and women are likely to have diabetes and cardiovascular disease for close to 20 years and die 8 years sooner than their normal-weight peers, researchers have estimated.
«We developed this computer model [to] provide a new but clinically meaningful way for healthcare professionals to engage patients in a discussion about how modest lifestyle changes [of modifiable risk factors] could improve their health,» lead author on the paper, Dr Steven A Grover (McGill University, Montreal, Quebec), told Medscape Medical News
«The pattern is clear: the more an individual weighs and the younger their age, the greater the effect of excess weight on health,» Grover and colleagues report in their paper, published online December 5 in Lancet Diabetes & Endocrinology.
The scientists assessed the risk of developing type 2 diabetes or cardiovascular disease for adults aged 20 to 79, analyzing how being overweight or obese contributes to healthy years of life lost and years of life lost compared with being of normal weight.
The effect of excess weight on these comorbidities and mortality lessened with increasing age, but even older individuals who were only overweight lost a substantial number of healthy years of life, despite a small or negligible reduction in mortality.
The risk estimates generated could potentially be used by physicians to help motivate patients, says Grover. «If you’re overweight and have dyslipidemia, high blood pressure, and elevated glucose, you only need to lose about 10 pounds and exercise 30 minutes most days of the week, and you can drop your risk of diabetes by 60%, based on other [randomized] trials,» he said.
But in an accompanying comment, Dr Edward Gregg (Centers for Disease Control and Prevention, Atlanta, Georgia) questions whether young people will be motivated to make lifestyle changes now to improve health later on.
Nevertheless, the study is important, because it takes a lifelong view that can help inform clinicians and policy makers, he writes.
Computer Modeling Study
Grover and colleagues used data from the Lipid Research Clinic Follow-up Study and from Atherosclerosis and Risk in Communities (ARIC) study to develop a model to predict the annual risks of developing type 2 diabetes and cardiovascular disease if a person had certain risk factors, such as high blood pressure and elevated glucose levels.
They then estimated the risk of developing these comorbidities in adults by age and body mass index (BMI), based on data from the 2003–2010 NHANES database in 2011 men and 1981 women who were white and aged 20 to 79.
The population was divided into three age groups (20–39, 40–59, and 60–79) and four weight categories: normal weight (BMI 18.5 to <25 kg/m2), overweight (BMI 25 to <30 kg/m2), obese (BMI 30 to <35 kg/m2), and very obese (BMI 35 kg/m2 and higher).
Importantly, this cardiometabolic model was validated using Framingham and other life-expectancy data.
The youngest, most obese individuals were most likely to have a shortened lifespan. Excess weight decreased longevity in men and women, and the effect lessened with increasing age.
Overall, healthy life-years lost were two to four times greater than years of life lost.
Years of Life Lost in Overweight/Obese Men, Women vs Normal-Weight Men, Women in the Same Age Range
Healthy Life-Years Lost in in Overweight/Obese Men, Women vs Normal-Weight Men, Women in the Same Age Range
Diabetes and Obesity Epidemics Are «Moving Targets»
In his comment, Gregg writes that the new findings from Grover and colleagues are generally consistent with previous studies showing that «young adults who are obese have more than a 50% lifetime risk of diabetes and cardiovascular disease, and those with severe obesity might expect to spend a third of their remaining life with a major chronic disorder.
«However, changing aspects of the epidemiology of obesity and diabetes might make healthy life-years a moving target,» he adds.
People with diabetes and CVD appear to be living longer, while there is an increase in conditions such as chronic kidney disease, for example.
Grover and colleagues say they intend to test the theory of whether younger obese individuals will be motivated to improve their health to prevent disease in later life: they have just started a randomized clinical trial in which some people will be given information about risks of excess weight by a community pharmacist and will be followed to see if they adhere to a healthy-eating, exercise, and weight-loss program
The study was funded by the Canadian Institutes of Health Research. Dr Grover acts as a consultant to Merck, Roche, AstraZeneca, and Amgen. Disclosures for the coauthors are listed in the article. Dr Gregg has reported he has no relevant financial relationships. His findings and conclusions do not necessarily represent official positions of the Centers for Disease Control and Prevention.
Lancet Diabetes Endocrinol. Published online December 5, 2014.