Our research group studies the effects of excess weight and obesity on health. These studies include adults with a range of body weights. We study fat distribution, metabolic rate, and exercise tolerance. We also examine hormone responses to meals and to glucose given through the blood stream. Patients donate samples of blood, urine, fat (taken from under the skin in the lower abdomen), and muscle (taken from the thigh). We use these specimens for gene expression studies and other research.
The Clinical Endocrine Section (CES) conducts research in the area of endocrinology and metabolism and has the ultimate goal of improving the health of patients through new discoveries and innovations. Within the CES, trainees at the premedical, medical, and post-graduate levels participate in patient-oriented research. Areas of major focus are detailed in the following sections.
The physical, hormonal, and behavioral traits and metabolic consequences of being overweight and obese in adults (Phenotype Study)
We are poised to translate new research results in the areas of obesity and metabolism. Our group uses technologies available within the NIDDK Metabolic Clinical Research Unit and core laboratories. As a part of our studies, we created a bank of well-characterized biospecimens—including plasma, urine, adipose tissue, and muscle—to test new hypotheses and facilitate collaborative work. We intensively study unique patient cohorts followed at the Clinical Center to characterize the impact of their condition or behaviors on metabolism.
Recently, we completed a study of the metabolic phenotype of cannabis users. We tested whether frequent marijuana smoking and chronic stimulation of CB1 receptors leads to hepatic lipogenesis and insulin resistance. In our comparison of marijuana smokers and weight-matched nonsmoker controls, we learned that hepatic fat did not differ between the groups, but smokers showed an increased proportion of fat in the visceral compartment. Insulin sensitivity was not impaired, however, and free fatty acid response to insulin was diminished. This finding suggests adipocyte impairment.
The melanocortin pathway regulation of energy expenditure and appetite in humans
The CES is studying melanocortin 4 receptor agonism on the components of energy expenditure in healthy obese adults. We are conducting this study in metabolic suites (room calorimeters) within the Metabolic Clinical Research Unit. This study includes a detailed assessment of resting energy expenditure and examines the thermic effect of a meal and exercise-induced and sleeping energy expenditure.
The diagnosis and treatment of diseases of the thyroid—including hyperthyroidism and hypothyroidism and benign and malignant thyroid tumors—through the study of common and rare variants
We enroll a wide variety of patients with thyroid disorders for clinical training and research studies. Our focus is on natural history studies that allow intensive examination of these disorders. Patients with thyroid cancer are also enrolled in a North American consortium called The National Thyroid Cancer Treatment Cooperative Study. Collaborators at NIH use tissues obtained during biopsy and surgical resection of tumors and normal thyroid.
Education of the next generation of specialists in endocrinology, diabetes, and metabolism while providing a fundamental education in clinical investigation
For more than 4 decades, the Inter-Institute Endocrinology Training Program has trained physician scientists for careers in academia, pharmaceutical development, and clinical practice. Some illustrious past clinical associates of the program include: Dr. John Bilezikian, Columbia University; Dr. Jeffrey Flier, Harvard Medical School; Dr. Marvin Gershengorn, NIDDK; Dr. C. Ronald Kahn, Joslin Diabetes Center; Dr. Reed Larsen, Peter Bent Brigham Hospital; Noble Prize winner, Dr. Robert Lefkowitz, Duke University Medical Center; Dr. Allen Spiegel, Dean of Einstein Medical College; and many others.
Throughout the years, the program has adapted to trends in graduate medical education and maintains accreditation by the Accreditation Council for Graduate Medical Education (ACGME). However, the mission remains unchanged: to provide physicians with an educational experience that encompasses unparalleled research opportunities in clinical and basic science