By Michael Smith
The risk of developing diabetes in adulthood is associated with weight in adolescence and weight gain during the teens and early 20s, researchers reported.
In a longitudinal cohort of teens and young adults, the timing of the weight gain also appeared to play a role in diabetes risk, according to Penny Gordon-Larsen, Ph.D., a professor at the University of North Carolina, Chapel Hill.
On the other hand, hypertension in adulthood was associated just with adult body mass index (BMI), while inflammation was linked only to increasing BMI, Gordon-Larsen and colleagues reported in the November issue of Obesity.
The findings imply that “specific periods and patterns of weight gain in the transition from adolescence to adulthood” play a role in the development of cardiometabolic risk factors such as diabetes, the researchers argued.
The findings are based on data from the National Longitudinal Study of Adolescent Health, a nationally representative longitudinal adolescent cohort that has been followed into adulthood.
For this analysis, the authors used data from the second, third, and last waves of the study — in 1996, 2001-2002, and 2008-2009, respectively — that included anthropometric information as well as such things as glycated hemoglobin levels, blood pressure, and C-reactive protein.
During the second wave, average BMI was 23.3 kg/m2, but the mean rose to 29 kg/m2 in the fourth wave.
And by the fourth wave, 5.5 percent of the participants had diabetes, 26.4 percent had high blood pressure, and 31.3 percent had inflammation.
The study hypothesis was that adults with the same age and BMI would have different risks for diabetes, hypertension, and inflammation depending on their BMI “trajectory” from adolescence to adulthood.
For all the risk factors, the researchers compared several trajectories with a “stable” path in which the BMI remained at 23 kg/m2 from age 15 to 27 years.
For diabetes, the outcomes included a higher risk for 27-year-old men with a BMI of roughly 30 kg/m2, who had gained 8 BMI units between age 15 to 20 years compared with the referent stable path (odds ratio 2.35, 95 percent CI 1.51-3.66).
That was similar to those who had started with a BMI of 30 kg/m2 and maintained it (OR 2.33, 95 percent CI 1.92-2.83).
But it was greater than the risk of those who had the same 8-unit gain from a base BMI of 23 kg/m2, but had it between age 20 to 27 years (OR 1.44, 95 percent CI 1.10-1.87).
For hypertension, the researchers reported, there was no association with early BMI or changes in BMI in adolescence or the early adult years.
Instead, the main predictor of high blood pressure was current BMI.
And, for women, it was the gain in BMI that mattered — regardless of BMI at age 15 or 27, a small gain over the intervening years was linked to a lower risk than a greater gain.
The authors cautioned that it’s possible that some people might have been diagnosed with a risk factor and therefore lost weight during the study period, which would weaken the associations.
They also noted that they could not distinguish between types of diabetes, which might weaken the associations between BMI and type 2 diabetes, which is thought to be associated with weight gain.