A high childhood body mass index (BMI) is associated with a high risk of obesity in adulthood. Several studies have shown adverse long-term outcomes of obesity in childhood, including type 2 diabetes mellitus and cardiovascular disease. It is unclear whether increased cardiovascular risk as an adult is a predetermined consequence of childhood obesity or whether these long-term adverse effects can be reversed in obese children who become nonobese as adults.
This observational study was designed to compare the risk of cardiovascular disease among obese and nonobese adults with and without a history of overweight or obesity during childhood. Data were pooled from 4 prospective cohort studies that tracked changes in cardiovascular risk factors among children into adulthood. The study cohort comprised 6328 subjects who were followed for 23 years. Adiposity status in children was defined according to international age- and sex-specific international BMI percentiles; cutoff points for childhood overweight and obesity corresponded to adult BMI cutoff points of 25 (overweight) and 30 (obese). The participants were divided into 4 groups: (1) individuals with normal BMI in childhood who were nonobese as adults (group I); (2) those overweight or obese in childhood who were nonobese as adults (group II); (3) those overweight or obese in childhood who were obese as adults (group III); and (4) those with normal BMI in childhood who were obese as adults (group IV).
Compared with subjects who were nonobese both during adulthood and childhood (group I), individuals obese both as adults and children (group III) were at significantly increased risk for type 2 diabetes (relative risk [RR], 5.4; 95% confidence interval [CI], 3.4–8.5), hypertension (RR, 2.7; 95% CI, 2.2–3.3), elevated low-density lipoprotein cholesterol levels (RR, 1.8; 95% CI, 1.4–2.3), reduced high-density lipoprotein cholesterol levels (RR, 2.1; 95% CI, 1.8–2.5), elevated triglyceride levels (RR, 3.0; 95% CI, 2.4–3.8), and carotid artery atherosclerosis (increased intima-media thickness of the carotid artery) (RR, 1.7; 95% CI, 1.4–2.2); P values were ≤0.002 for all comparisons). Cardiovascular risk factors among participants overweight or obese during childhood but nonobese as adults were similar to those observed among individuals with a consistently normal BMI both as children and adults; P > 0.20 for all comparisons.
These findings suggest that the risk of cardiovascular disease in children and adolescents who are overweight or obese and become nonobese in adulthood is no higher than that observed among persons with consistently normal BMI both as children and adults. Individuals overweight or obese as adults, irrespective of their childhood BMI, are at substantial risk of cardiovascular disease.