Obesity affects even ‘good’ cholesterol
in teen boys at risk for type 2 diabetes

Published November 01 2017

Childhood obesity brings an increased risk of adolescent type 2 diabetes, a metabolic disease characterized by an increase in blood glucose levels. People with type 2 diabetes are insulin-resistant, meaning the body is no longer sensitive to the insulin it produces. Individuals may be diagnosed as prediabetic if their blood glucose levels are not high enough to be considered diabetic. To improve health, anyone with type 2 diabetes needs significant lifestyle changes, such as increased exercise or restricted diet to control glucose levels.

Type 2 diabetes increases imminent and latent health risks. In adolescents, type 2 diabetes has been connected with early signs of cardiovascular disease, or CVD (1). About 70 percent of adults with type 2 diabetes die of cardiovascular complications (2). Researchers want to discover treatments to reduce CVD risk for adolescents and adults with type 2 diabetes.

But of the three type 2 diabetes risk factors — blood glucose levels, insulin resistance and obesity — which is most strongly associated with the risk of CVD in youth? After analyzing risk factors among male adolescents with type 2 diabetes, a research group lead by Amy S. Shah at Cincinnati Children’s Hospital Medical Center and W. Sean Davidson at the University of Cincinnati found that obesity was most strongly correlated with abnormal lipids that increase the risk for heart disease. Their research was published in a recent issue of the Journal of Lipid Research.

To associate blood glucose levels, insulin resistance and obesity with early risk for CVD, Shah’s research group looked at the different subspecies of high-density lipoprotein across groups of adolescent males. HDL refers to a class of lipids that usually are referred to as “good cholesterol.” Instead of just looking at the HDL cholesterol numbers, Shah and her colleagues summarized the total distribution of HDL particle sizes by measuring an HDL particle profile for each individual. The HDL profile grouped the subspecies into six differently sized subcategories. Previously, Shah had identified a specific HDL profile in youth with type 2 diabetes that was unlike that in healthy adolescents. Adolescents with this distinct profile, indicative of type 2 diabetes, also showed early signs of heart disease (1). In the recent study, Shah analyzed HDL profiles from male youth who exhibited some of the risk factors for type 2 diabetes but were not yet diagnosed with the disease.

“We found obesity was the major risk factor associated with the altered HDL subspecies profile previously reported in adolescents with type 2 diabetes, with smaller contributions from insulin resistance and diabetes,” Shah said. For individuals with type 2 diabetes, this study suggests that weight loss might be the most beneficial action for adjusting the HDL profile away from one with an increased risk for CVD.

This research suggests additional courses of action to study in the future. To separate the effects of the various risk factors, only male subjects were included in the four test groups. Future research could focus on how these factors affect the HDL profiles in female adolescents. Additionally, changes beyond the size of the different HDL particles, such as changes in structure and function, could provide further insight.

“We hope this article highlights that not all HDL is equal,” Shah said, “and that quantifying traditional lipid measurements may not always give the most information about CVD risk.”

1. Gordon, S. M. et al. Diabetes 62 (8), 2958-2967 (2013).
2. Panzran, G. Diabetologia 30 (3), 123-131 (1987).

Lauren Borja Lauren Borja is a science writer with a Ph.D. in physical chemistry from the University of California, Berkeley.