Investigators determined that children who lose excess weight prior to young adulthood could face no increased risk of coronary heart disease compared with peers who maintained normal weight throughout childhood and into young adulthood, according to findings from a population-based cohort study.
In the BMI Epidemiology Study, the investigators followed 103,232 patients born between 1945 and 1968, measuring weight in childhood and young adulthood and then following participants for nearly 40 years. Among the 4,091 patients with childhood overweight who achieved normal weight by young adulthood, coronary heart disease (CHD) risk matched that of the participants who never had overweight.
"Remission of childhood overweight before young adulthood resulted in a similar risk of CHD as in individuals who had persistent normal weight," reported lead study authors Claes Ohlsson, PhD, of the Centre for Bone and Arthritis Research in the Department of Internal Medicine and Clinical Nutrition at the University of Gothenburg, and colleagues.
During 3.9 million person-years of follow-up through December 31, 2021, the investigators documented 5,736 first CHD events (4,438 in male patients and 1,298 in female patients) and 931 fatal CHD events (763 in male patients and 168 in female patients). The cohort included 45,965 female participants and 57,267 male participants with mean childhood body mass index (BMI) of 16.
Both persistent overweight, defined as overweight in childhood and young adulthood, and pubertal onset overweight—normal weight in childhood and overweight in young adulthood—showed elevated CHD risk compared with persistent normal weight. However, patients with pubertal onset overweight demonstrated 23% higher risk compared with those who had persistent overweight.
Patients with pubertal onset overweight and persistent overweight showed a respective 83% and 53% increased likelihood of adult CHD events compared with those maintaining normal weight.
The study utilized International Obesity Task Force cutoffs for childhood overweight, defining young adult overweight as BMI of 25 or greater to less than 30, and obesity as BMI of 30 or higher. The investigators linked archived school health records to Sweden's National Patient Register, initiated in 1964 with full Gothenburg coverage from 1972, and the Cause of Death Register covering deaths since 1961.
When the investigators included childhood and pubertal BMI changes as continuous variables in statistical models, pubertal BMI change was associated with CHD events in the total cohort, regardless of sex. In contrast, childhood BMI showed no independent association with CHD events when adjusted for young adult weight status.
The correlation between childhood BMI and pubertal BMI change proved marginal in both sexes, whereas correlation between childhood BMI and young adulthood BMI was strong in both male and female participants.
Additional analyses using the 85th percentile as the cutoff for high BMI confirmed the primary findings. Patients with high childhood BMI (greater than the 85th percentile) who achieved normal young adulthood BMI (the 15th to 85th percentiles) showed no increased CHD risk vs those with normal BMI at both timepoints. The highest CHD risk emerged among patients with low childhood BMI (less than the 15th percentile) and high young adulthood BMI (greater than the 85th percentile), showing more than twice the risk compared with those maintaining normal BMI.
No statistically significant sex interaction appeared for the associations between childhood overweight and CHD events or between young adulthood overweight and CHD events. Adjustment for socioeconomic status, defined as educational attainment at age 45 years, didn't alter results.
Sensitivity analyses excluding patients with cancer, diabetes, or specific procedure codes prior to age 22 years, as well as analyses restricted to Swedish-born patients with Swedish-born parents, yielded similar findings. Competing risk analyses using the Fine and Gray model produced comparable results.
The investigators noted study limitations, including the inability to adjust for smoking status and other lifestyle factors, though previous studies found such adjustments didn't alter young adult BMI effects. The cohort was predominantly White, potentially limiting generalizability. The 28% of eligible patients excluded because of missing BMI measurements or events prior to age 22 years didn't differ substantially in BMI from included participants, though excluded female participants showed slightly higher CHD prevalence.
Disclosures can be found in the study.
Source: JAMA Pediatrics