Lifestyle intervention plus metformin therapy could help obese adolescents who are at risk for diabetes reduce their body fat percentage and improve their insulin sensitivity, according to research published in The Journal of Clinical Endocrinology & Metabolism.
Australian researchers also observed vascular elasticity changes in an ancillary study of the RESIST trial, but follow-up is needed to determine the effect on cardiovascular morbidity and mortality.
“To our knowledge, this is the first longitudinal study to examine the effect of fat loss on arterial elasticity and vascular tone, measured by diastolic pulse contour analysis (PCA), in adolescents with obesity,” the researchers wrote.
Mandy Ho, MSc, RN, of The Children’s Hospital at Westmead in Sydney, Australia, and colleagues looked at 56 adolescents (25 males) aged 10 to 17 years with obesity and prediabetes, as defined by the American Diabetes Association, and/or clinical features of insulin resistance.
The adolescents participated in a 12-month program of structured dietary intervention, supervised physical activity, ongoing support and a maintenance phase; half of participants were eating a high-carbohydrate diet and the other half a moderate-carbohydrate, increased-protein diet. All participants were treated with 500 mg metformin twice daily.
The researchers used radial tonometry PCA to measure arterial elasticity and systemic vascular resistance and DXA to measure percent body fat. Insulin sensitivity index was derived from an oral glucose tolerance test and lipids.
In 31 adolescents who demonstrated decreased percent body fat (mean change, –4.4%), researchers also observed increases in large arterial elasticity index (mean change, 5.1 mL/mm Hg x 10; P=.003) and insulin sensitivity index (mean change, 0.5; P=.01) and a decrease in systemic vascular resistance (mean change, –82 dyne x sec x cm-5; P=.001). No significant changes were seen in these parameters for adolescents whose percent body fat increased. Small arterial elasticity index did not change significantly in either group.
“It is important to follow up these adolescents for longer term to examine whether these changes in vascular elasticity and metabolic profile will attenuate the progression of subclinical cardiovascular disease and prevent the development of subsequent cardiovascular events,” the researchers wrote.
Disclosure: Please see the study for a full list of researchers’ financial disclosures.