All-Cause, Cause-Specific Mortality Increased With Elevated BMI

HealthDay News — Maximum BMI over 16 years of weight history is associated with increased risk of all-cause death, according to a study published online in the Annals of Internal Medicine.

Edward Yu, from the Harvard T.H. Chan School of Public Health in Boston, and colleagues examined the correlation between maximum BMI over 16 years and mortality in 225,072 men and women from the Nurses’ Health Study I and II and the Health Professionals Follow-Up Study. Over a mean follow-up of 12.3 years, 32,571 deaths were observed.

The researchers found that maximum BMIs in the overweight, obese I, and obese II categories correlated with increases in the risk for all-cause death (multivariate hazard ratios [HR]: 1.06, 1.24, and 1.73, respectively). Across strata defined by smoking status, sex, and age, the pattern of excess risk with a maximum BMI above normal weight was maintained, with greatest excess seen for those younger than 70 years and never smokers. When BMI was defined using a single baseline measure, there was a significant inverse association between overweight and mortality (HR: 0.96). Maximum overweight correlated with increased cause-specific mortality, including cardiovascular death and coronary heart disease death.

“The paradoxical association between overweight and mortality is reversed in analyses incorporating weight history,” the authors write. “Maximum BMI may be a useful metric to minimize reverse causation bias associated with a single baseline BMI assessment.”

References

1. Yu E, Ley SH, Manson JE, et al. Weight history and all-cause and cause-specific mortality in three prospective cohort studies [published online April 4, 2017]. Ann Intern Med. doi: 10.7326/M16-1390
2. Despres J-P. Overweight: the body mass index category with an identity crisis [published online April 4, 2017]. Ann Intern Med. doi: 10.7326/M17-0566