Childhood obesity and other cardiovascular risk factors associated with premature death

Childhood obesity, glucose intolerance, and hypertension, but not hypercholesterolemia, predict premature death from endogenous causes. This finding comes from a study of nearly 5,000 American Indians younger than 20 years old without diabetes at baseline who were followed for more than 2 decades. The authors of the study suggest that the global trend of childhood obesity could lead to shorter life spans and that obesity prevention needs to start early in life.

In this study (N Engl J Med. 2010;362[6]:485-493), the investigators enrolled 4,857 American Indian children and adolescents (aged 5 to <20 years) from a community in Arizona. All participants were free of diabetes when enrolled. At baseline, measurements of body mass index (BMI), 2-hour plasma glucose level, blood pressure, and total cholesterol were performed. The authors assessed how these risk factors affected premature death attributed to endogenous causes, defined as death caused by disease or self-inflicted injury, over a median follow-up of 23.9 years (range, 0.04-37.9 years).

A total of 11.5% of the participants died before they were aged 55 years. Of the 166 deaths from endogenous causes, alcoholic liver disease accounted for the most (59), followed by cardiovascular disease (22), infections (21), cancer (12), diabetes or diabetic nephropathy (10), and acute alcoholic poisoning or drug overdose (9). Thirty-three deaths were attributed to other causes.

Children with 2-hour plasma glucose level in the highest quartile at baseline had a 73% increased risk of premature death from endogenous causes compared to children in the lowest quartile, but adjusting for BMI reduced this increased risk to 24%. There was no association between cholesterol levels or blood pressure and death rates, but childhood hypertension was associated with a 57% increased risk of death from endogenous causes.

The lack of a significant association between cholesterol level and premature death may be partially attributable to the low rate of cardiovascular death (13.3%) during follow-up, the authors speculated. Longer follow-up may be needed for elevated cholesterol to emerge as a significant risk factor for mortality, they added.

The authors noted that high BMI and weight gain during childhood have been associated with excess mortality in other studies. A high childhood BMI may reflect adverse lifestyle factors (eg, inactivity, excess calorie intake, poor nutrient choices) that may also contribute to premature death.