Decline in Beta-Cell Function among Adolescents with Type 2 Diabetes Mellitus
It is well known that beta-cell function declines over time in adults with type 2 diabetes mellitus (T2DM). The beta-cell dysfunction, initially characterized by impairment in the first phase of insulin secretion following glucose stimulation, advances to a decline in second phase insulin secretion as the disease progresses. But whether this decline in beta-cell function occurs in adolescents with T2DM is uncertain. Investigators prospectively compared beta-cell functioning over time between 39 adolescents with newly diagnosed T2DM (mean age, 15 years; body-mass index z-score, 2.4) and 32 obese adolescents without T2DM of comparable body-mass index, gender, and race (mean age, 14) during a 2-year period. Recently, researchers from Duke University School of Medicine, Durham North Carolina reported that adolescents with newly diagnosed T2DM had a 25% annual decline in beta-cell function despite receiving treatment. In this study, the results of which were first presented at the American Diabetes Association (ADA), the participants were adolescents with T2DM, more than half of whom were being treated with insulin whereas 80% were taking oral anti-diabetes medications. Beta-cell function in this study, assessed at baseline and 6, 12, and 24 months was measured by insulin secretion in response to an intravenous glucose load adjusted for insulin sensitivity (disposition index). The authors observed that adolescents with T2DM had significantly higher levels of both insulin resistance and fasting glucose at baseline compared with controls. But during the two-year study, the study subjects experienced a significant increase in fasting glucose and a 25 percent annual decline in disposition index. Understandably, both these indicators remained unchanged among the controls. JMS 2017;20(2):116