Childhood Obesity Can Affect Cardiovascular Risk Even If Resolved by Adulthood

Not only does a person’s current body mass index (BMI) affect his or her cardiometabolic risk, but having a childhood history of obesity does as well, according to new findings. As such, physicians should pay attention to their patients’ BMI trajectories over time and tailor treatment accordingly, while efforts more broadly should try to curb excess weight among children, the authors say.

“Our observational data suggest that stabilizing BMI among obese adults could help limit their adverse CVD risk profiles and that reversing high BMI in young adulthood may lead to better cardiometabolic profiles than remaining stable overweight,” write Marie-Jeanne Buscot, PhD (University of Tasmania, Hobart, Australia), and colleagues. “These findings align with recent consensus guidelines highlighting the importance of lifestyle changes to substantially reduce CVD risk. Obesity prevention should ideally target children to effectively attenuate preclinical atherosclerosis risk.”

Their study, published online last week ahead of print in the European Heart Journal, included 2,631 participants from the Cardiovascular Risk in Young Finns Study who had their height and weight measured on at least three occasions between 1980 and 2011 and were designated into six different life-course BMI trajectories:

• Stable (55.2%): average BMI levels remained within the normal range
• Progressively overweight (33.4%): BMIs increased over time, with individuals being overweight by their 30s
• Progressively obese (4.2%): BMI levels increased over time, with individuals being overweight in childhood and obese by early adulthood
• Rapidly overweight/obese (4.3%): individuals were borderline overweight in early childhood, obese in mid-childhood, and obese with stable BMIs by age 20
• Persistent increasing overweight/obese (1.2%): BMIs persistently increased over time, with individuals being obese throughout their life
• Resolving (1.6%): individuals were overweight or obese during childhood, obese by age 25, and progressively reversed their elevated BMI status between ages 30 and 50

Compared with the stable cohort, all individuals with increasing BMIs over their lives were at significantly higher risk for type 2 diabetes, hypertension, high-risk carotid intima-media thickness (cIMT), and high-risk lipid levels.

Those in the resolving group were found to have a similar risk for dyslipidemia and hypertension as those who had never been obese or overweight, but they were at a more than threefold higher risk for increased cIMT (RR 3.37; 95% CI 1.80-6.39) and at a slightly higher (although not statistically significant) risk for type 2 diabetes (RR 2.13; 95% CI 0.14-8.23). These effects were somewhat attenuated after adjustment for family history, adult socioeconomic status, and adult physical activity level.

“Our findings are consistent with previous studies showing that ‘excess BMI-years’ increase risk of type 2 diabetes mellitus and CVD risk factor levels,” Buscot and colleagues write.

“The more than doubled risk difference observed for adult type 2 diabetes mellitus in the resolving class compared with the normal stable class suggested a potential residual effect of child overweight/obesity on adult type 2 diabetes mellitus risk, even with resolution of BMI status later in life,” they add. “However, because the CIs for this estimate included the null, this finding needs to be confirmed in further studies with a larger number of resolvers.”

With regard to predicting adult risk of hypertension, “the cumulative burden of the number of life-years spent obese may be a stronger predictor,” they say. “These data suggest that completely reversing high BMI, even after childhood, is beneficial for most outcomes.

Nevertheless, the cIMT results suggest that “elevated BMI status in early life may alter arterial structure in a way that is not reversible,” they say. This “emphasizes the potential importance of childhood obesity prevention to attenuate the risk of preclinical atherosclerosis,” Buscot and colleagues conclude.