Premature death linked to childhood obesity, glucose intolerance, hypertension

Issue: March 2010

Obesity, glucose intolerance and hypertension in children without diabetes appear to be significant predictors of premature death from endogenous causes later in life. However, childhood hypercholesterolemia was not deemed a major predictor, according to new study findings.

Researchers assessed BMI, glucose tolerance, blood pressure and total cholesterol levels in 4,875 American Indian children (mean age, 11.3 years) without diabetes who were born between 1945 and 1984. Proportional hazard models adjusted for baseline age, sex, birth cohort and tribe (Pima or Tohono O’odham) were used to determine if these risk factors were correlated with death before the age of 55 years.

During a median follow-up of 24 years, 559 (11.5%) of the original 4,857 participants died before the age of 55 years. Endogenous causes were linked to 166 (3.4%) of the deaths, including alcoholic liver disease, cardiovascular disease, infections, cancer, diabetes or diabetic retinopathy, acute alcohol poisoning or drug overdose, and other causes.

Researchers reported a positive association between BMI and risk for premature death caused by endogenous causes (incidence rate ratio per one unit of BMI z score=1.4; 95% CI, 1.20-1.63). Children in the highest quartile of BMI had significantly higher rates of death from endogenous causes — more than double compared with children in the lowest quartile (IRR=2.3; 95% CI, 1.46-3.62).

Children in the highest quartile of two-hour plasma glucose levels during a 75-g oral glucose tolerance test had a 73% higher risk of death linked to endogenous causes compared with children whose glucose levels were in the lowest quartile (IRR=1.24; 95% CI, 0.79-1.96).

No significant observations were reported between premature death from endogenous causes and childhood cholesterol or blood pressure levels on a continuous scale. However, childhood hypertension was linked to a higher rate of premature death from endogenous causes (IRR=1.57; 95% CI, 1.10-2.24).

The researchers postulated that the association between premature death from endogenous causes and cholesterol levels may be related to the low proportion of deaths related to cardiovascular disease (13.3%) in this American Indian population. Further, “cholesterol levels … are lower in American Indians than they are in most other ethnic groups, a finding that may partially explain the absence of association for this trait.

“Although we studied a population with high rates of obesity and diabetes, our findings may reflect the future burden of premature death among contemporary children from other ethnic groups and may be more generalizable than the findings in previous studies,” the researchers wrote. - by Matt Brannon

Franks WF. N Engl J Med. 2010;362:485-493.

Franks et al report that obesity, glucose intolerance and hypertension in youth significantly increase risk for premature death among a large cohort of Pima and Tohono O'odham children born between 1945 and 1984 - a group with high rates of obesity and diabetes. While this population is unique, obesity in contemporary youth has now risen to comparable rates. Therefore, such data suggest that the current high rates of obesity in youth of all ethnic groups may predict a concerning increase in premature death, arguing for a continued critical need for public health and research focus on preventing and reducing obesity in youth.

- Kristen Nadeau, MD
Assistant professor of pediatrics, University of Colorado Health Sciences Center