The Kirwan Laboratory conducts clinical translational research in obesity and age-related insulin resistance and type 2 diabetes. Our research examines how exercise and nutrition alter disease risk associated with insulin resistance, obesity, and type 2 diabetes in older adults.
Increasing exercise and modifying diet are first-line treatments for insulin resistance and diabetes. We found that the combination of exercise and a low glycemic diet is three times more effective at reversing insulin resistance than standard exercise and diet therapy. Our ongoing NIH-funded clinical studies are examining the underlying cellular mechanisms that may explain these observations.
Nonalcoholic fatty liver disease (NAFLD) is emerging as a major health problem in the US and when combined with type 2 diabetes is a major cause of liver related mortality. We are assessing the effects of exercise on hepatic lipid content, hepatic and peripheral insulin resistance, and oxidative stress.
These studies combine clinical measures of insulin resistance (clamp infusions, tracer isotopes, glucose tolerance testing), body composition (dual-energy X-ray absorptiometry, computed tomographic scanning, magnetic resonance imaging and spectroscopy) and exercise (VO2max testing) with cellular measures (protein and mRNA expression, enzyme activity, insulin signaling) in skeletal muscle and adipose tissue samples. Our clinical studies are conducted in Cleveland Clinic’s General Clinical Research Center; bench analyses are performed in the LRI.
In addition to our exercise/diet studies in older adults, we are working on research questions related to lipid-induced insulin resistance (in vivo and in silico) and on energy metabolism and insulin resistance in conditions such as the metabolic syndrome, colon cancer, and hepatitis C and in bariatric surgery.
Work is also ongoing to examine the effects of external counterpulsation (ECP) on peripheral blood flow and the reversal of insulin resistance in type 2 diabetes mellitus.
Obesity is a leading global health problem and is linked to multiple chronic diseases including insulin resistance, type 2 diabetes, liver disease, heart disease, stroke and certain types of cancer. Here in the Kirwan lab, we are focused on developing exercise, dietary and surgical interventions, and medical devices that can most effectively reverse many of these chronic diseases.
If you are overweight, a non-smoker and aged between 18 and 70, you may be eligible for one of the studies listed below. If you would like to participate in one of these studies please call Julianne Filion, RN, on 216- 445- 5553 or one of our research coordinators on 216- 444-8460.
Our long-term goal is to identify effective ways to improve health and prevent obesity and related chronic diseases. The type of diet that you eat can have a huge effect on your health. The goal of this study is to measure the effects of two different types of diet on energy balance and body fat distribution in overweight and moderately obese adults. We would like to know how diets that differ in carbohydrate and fiber content affect body weight and metabolism. To answer this question participants will be required to eat two different diets over a period of 8 weeks each. All of the food will be provided by the study. Body weight and body composition, and various measures of metabolism will be made before and after each of the diet periods.
Various scans, infusions and questionnaires will be performed.
Research will involve overnight stays in the Cleveland Clinic Clinical Research Unit
Non-Alcoholic Fatty Liver Disease (NAFLD) is one of the most common forms of chronic liver disease in the US. It is closely associated with the current obesity epidemic and it is estimated that 20-30 % of adult Americans are affected, many without knowing it. If left unchecked NAFLD can result in the development of Non-Alcoholic Steatohepatitis (NASH), Cirrhosis and Hepatic Cancer. In addition, given the central role of the liver in regulating metabolism, NAFLD is believed to play a significant role in the development of Type 2 diabetes and associated cardiovascular complications.
We are currently investigating whether short-term aerobic exercise training can reduce the amount of fat in the liver. Liver fat will be measured using an MRI scan. It is hoped that this research will demonstrate the potential for MRI to be used as non-invasive diagnostic test for NAFLD and NASH, and the findings may open up the opportunity to provide new treatments for fatty liver disease.
If you are between 18-70 years, overweight, and a non-smoker you may be eligible to take part in this study.
Many individuals with type 2 diabetes suffer from reduced blood flow to the legs and feet. Without adequate treatment, this can lead to debilitating conditions such as peripheral arterial disease (PAD). Our goal in this study is to evaluate ECP as a treatment option to halt the progression towards reduced peripheral blood flow in people with type 2 diabetes, and to examine whether any improvements in glucose metabolism may also occur as a result.
External counterpulsation therapy has been used in the treatment of coronary artery disease for many years. The device uses pneumatic pressure cuffs worn on the legs that inflate rhythmically to increase blood flow. It is hoped that the current study will demonstrate its ability to also treat conditions associated with type 2 diabetes.
If you are between 30-70 years, have type 2 diabetes, and are a non-smoker you may be eligible to take part in this study.
If you are overweight, a type 2 diabetic, and between the ages of 18 and 60 years, you may be eligible for an NIH funded study that is examining how Gastric Bypass surgery can reverse type 2 diabetes. This study is now open to enrollment. If you are interested in participating please call Chytaine Hall at 216-445-3983 or visit http://clinicaltrials.gov/ct2/show/NCT01278823
Treatment of obesity and type 2 diabetes is a major medical challenge. There is evidence that bariatric surgery is effective in producing long-term weight loss in extremely obese patients, and recent research suggests that it may also resolve type 2 diabetes. However, direct evidence of the glycemic benefits of bariatric surgery, specifically gastric bypass surgery, for patients with type 2 diabetes but who are not extremely obese is lacking, and the mechanisms that could make this happen are the subject of intense scientific debate. The proposed research will compare Roux-en-Y gastric bypass surgery with Intensive Medical Therapy using a randomized control trial in overweight and moderately obese patients with type 2 diabetes.
This study will last ~18 months.
Various scans, infusions and questionnaires will be performed.
Research will involve overnight stays in the Cleveland Clinic Clinical Research Unit
