Losing weight before young adulthood eliminates increased risk of type 2 diabetes

Published on 13/06/2017

Males who are overweight in childhood but achieve normal weight as young adults do not have an increased risk of type 2 diabetes in adulthood, compared to men who were never overweight. The DynaHEALTH study titled “Are Adverse Effects of Child Overweight on Risk of Type 2 Diabetes Reversible by Remission to Normal Weight in Young Adulthood?” was presented at the American Diabetes Association’s 77th Scientific Sessions® in San Diego this month.  

Being overweight in childhood and young adulthood is typically associated with an increased risk of developing type 2 diabetes later in life. To determine whether overweight boys who normalize their weight from age 7-18 could reverse the negative impact of being overweight in childhood, this study examined the links between overweight patterns defined as combinations of weight status in childhood and young adulthood, and later development of type 2 diabetes. 

The study, part of the DynaHEALTH project, funded by the European Commission’s Horizon 2020 program, analyzed the health data of 62,565 men from the Copenhagen School Health Records Register in Denmark, and the Danish Conscription Database, who had weight and height measured at the age of seven, and in young adulthood (17-26 years). The study defined “overweight” based upon the U.S. Center for Disease Control and Prevention (CDC) guidelines for childhood obesity and the World Health Organization Body Mass Index (BMI) classifications for young adulthood. 

The research analysis indicates that being overweight in childhood (5.4 percent of the men) and in young adulthood (8.2 percent of the men) was associated with increased risks of type 2 diabetes (HR7years=1.53 [1.40-1.68]; HRadult=2.96 [2.78-3.15]). A total of 6,710 of the men were classified as having type 2 diabetes at 30 years of age or older, according to the Danish National Patient Register. While 40 percent of the males in the study who were overweight as children were also overweight in young adulthood, boys who normalized their weight by young adulthood had a comparable risk of type 2 diabetes as men who were never overweight (HR=1.01 [0.87-1.16]). Men who were persistently overweight or became overweight as young adults had three times the risk of developing type 2 diabetes, as compared with non-overweight men who were overweight as children (HR=2.88 [2.40, 3.44] and HR=2.95 [2.53, 3.45] respectively). Hazard ratios (HR) and 95 percent confidence intervals were estimated by Cox regressions.

“These findings suggest that adverse metabolic health consequences of being overweight in childhood may possibly be reversed,” said the study’s lead author Lise G. Bjerregaard, PhD, postdoctoral research fellow in the department of clinical epidemiology, Frederiksberg Hospital in Copenhagen, Denmark. “We expected that overweight boys who reach normal weight by age 18 could reduce their risk of developing type 2 diabetes. However, we were excited to discover that achieving normal weight by young adulthood resulted in the same risk level as men who had always been of normal weight.” 

“Our results highlight the need for normalizing weight among overweight children before they reach adulthood,” explained Bjerregaard. “Prevention and treatment interventions of overweight pediatric populations should be a priority in many countries around the world, especially where there are higher incidences of obese children and rising rates of type 2 diabetes.”

Read the Danish Diabetes Association's interview with the study's lead author. Please note the article is in Danish.

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