Measurement of Insulin Resistance in Older Adolescents and Young Adults with Type 1 Diabetes
Pamela A. Martyn-Nemeth, PhD, RN
The long-term objective of this program of research is to decrease the risk of micro- and macrovascular complications in people with type 1 diabetes (T1DM) through early identification and management of risk factors. Traditional risk factors do not completely explain the risk of micro- and macrovascular complications in adolescents and young adults with T1DM. Insulin resistance (IR) is a known potent risk factor for cardiovascular disease (CVD) in the general population and is thought to play a critical role in accelerating the onset of chronic complications in both T1DM and type 2 diabetes (T2DM). Methods to estimate IR using simple, relatively non-invasive measures have been developed for non-diabetic and T2DM individuals, but these are not valid in T1DM due to the complete absence of functioning insulin-producing pancreatic β cells. Unfortunately, the “gold standard” for measuring insulin sensitivity in T1DM, the hyperinsulinemic euglycemic clamp technique (glucose clamp), is impractical for larger population-based studies. The primary aim of our larger study is to develop an estimate of IR, using a specific combination of demographic, anthropometric, clinical, and biomarkers validated against insulin sensitivity derived from the clamp method in an ethnically/racially diverse sample of adolescents and young adults with diabetes. The specific aims of this pilot study are to evaluate the glucose clamp procedure in a sample of 3 adolescent and young adults (aged 18 -25) with T1DM, examine the relationships among biologic, vascular, behavioral, and psychological risk factors, and evaluate the subject recruitment plan. Subjects will be recruited through physicians at the University of Illinois Medical Center Clinics (UIMCC). Those that meet the eligibility criteria will be scheduled for a screening visit and completion of questionnaires at the Clinical Research Center (CRC) at UIMCC. Three days after the screening visit they will return to the CRC to undergo the glucose clamp procedure. Feasibility of recruitment will be evaluated based on the numbers of recruitment letters sent/distributed in comparison to the number of subjects recruited as well as the ability to achieve the recruitment goal. Descriptive statistics, graphical figures, tables and plots will be used to summarize the biological, vascular, behavioral and psychological data.