Diabetes Prevention Program at The University of Chicago
The University of Chicago was selected to participate as a site in this study, the Diabetes Prevention Program (DPP). This area of Chicago is comprised primarily by African-Americans, a target-population identified by the NIDDK as at high risk for diabetes. In addition, our center’s results were consistent with those of the larger DPP study group which has substantiated (The DPP Research Group 2002) that appropriate interventions can successfully reduce the conversion rate from impaired glucose tolerance (IGT) to type 2 diabetes (The DPP Research Group 2002, Edelstein 1997). We have been funded by the NIH/NIDDK to continue as a clinical site in this program.
Polycystic Ovarian Syndrome
PCOS develops when the ovaries overproduce androgens (e.g. testosterone). Androgen overproduction often results from overproduction of LH (luteinizing hormone), which is produced by the pituitary gland.
Research also suggests that when insulin levels in the blood are high enough, the ovary can be stimulated to produce more testosterone. That is, the combination of having ovaries which are responsive to insulin and high insulin levels in the blood can result in the overproduction of testosterone.
Several faculty members in the section of Endocrinology are conducting studies on the roles of sleep and circadian rhythmicity in glucose regulation and hormonal release and their implications for the aging process and the development of age-related chronic conditions such as type 2 diabetes. Recent work has demonstrated that chronic sleep curtailment or chronic reductions of sleep quality result in decreased glucose tolerance. Thus, reduced sleep duration and/or quality, as occur in aging, appear to be previously unrecognized risks factor for diabetes. The findings also suggest that sleep loss may accelerate the development or increase the severity of the metabolic syndrome and that, conversely, having sufficient amounts of sleep at all ages may improve markers of metabolic function. Ongoing research tests the hypothesis that “paying the sleep debt” in individuals with short sleep who have impaired glucose tolerance or diabetes may improve glycemic control and seek to define “sleep need’ as the amount of sleep that optimizes metabolic and endocrine function. Several projects are focused on the prevalence and implications of sleep disorders in diabetes and endocrine conditions, such as the polycystic ovary syndrome and adult growth hormone deficiency. A number experimental protocols for in vivo assessment of beta cell function, including the use of oscillatory glucose infusion to entrain insulin pulsations have been developed.
Osteoporosis and Metabolic Bone Disease
Bone mineral density (BMD) is not a perfect predictor of fractures, primarily because it measures bone quantity but not its quality or trabecular structure, which also influences. Assessment of trabecular structure, particularly if obtained in a non-invasive and practical way, would provide significant additional information to aid clinicians in diagnosing and treating osteoporosis. We are developing a new method for non-invasive assessment of bone structure using Radiographic Texture Analysis (RTA) performed on radiographic and densitometric bone images. Studies are underway investigating whether information derived from RTA improves the assessment of bone fragility and facilitates monitoring of pharmacological therapy for osteoporosis.
The second area of research interest is investigating racial and individual differences in the risk of developing osteoporosis and other complications of long term therapy with glucocorticoids. It is well known that are large individual differences in the probability of developing complications of glucocorticoid therapy. The reasons for these differences are not clear yet are very important in guiding physicians in selecting patients for who need aggressive evaluation and treatment of glucocorticoid-induced osteoporosis. We are looking for possible genetic or phenotypic differences that underlie the vulnerability to glucocorticoid-induced osteoporosis.
Islet Cell Transplantation
The Section of Endocrinology, Diabetes and Metabolism has recently been established as a Center for Islet Transplantation to develop new ways of inducing immune tolerance and improving management of Type 1 diabetes and other immune system disorders. These initiatives add to the solid core of research programs that Endocrinology faculty are actively pursuing – from the biologic and genetic basis of normal glucose tolerance to understanding the basic aspects of insulin-secreting cell function through biophysics and cell biology, and from studies which aim to identify people at risk for diabetes prior to the onset of elevated glucose concentrations to investigations which aim to develop novel approaches to the early diagnosis and treatment of Type 1 and Type 2 diabetes.