Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
The purpose of this study is to evaluate the relationship between insulin resistance (IR) and myocardial tissue abnormalities. The study will focus on a patient population, South Asians, with a high prevalence of IR.
Cardiac fibrosis has been linked to adverse outcomes in non-ischemic cardiomyopathy. Fibrosis is also detectable in diabetic patients, but does not appear to closely track with insulin sensitivity. Hence, fibrosis may be an independent risk factor for adverse outcomes in IR and diabetic patients. As a result, a critical need exists to develop a non-invasive tool to identify and treat the highest-risk patients. Early detection of cardiac fibrosis and other CMR- detectable abnormalities in IR patients may help to 'stage' a patient's disease process and future risk of events, ultimately leading to an adjustment in the aggressiveness of their medical management and long-term monitoring accordingly. This project is aimed at reducing the mortality and morbidity associated with insulin resistance and diabetes, and the investigators believe this project could have a transformative impact on long-term diabetic care and shed new light upon the biology of diffuse cardiac fibrosis in insulin resistance and diabetes and its role in shaping the long-term cardiovascular risk for these patients.
Not provided
Not provided
Not provided
Not provided
Not provided
| Label | Type | Description | Intervention Names |
|---|---|---|---|
| South Asians with Insulin Resistance | 125 patients (anticipated) | ||
| South Asians without Insulin Resistance | 125 patients (anticipated) |
Not provided
| Measure | Description | Time Frame |
|---|---|---|
| Identifying patients with high fibrosis levels using peripheral blood samples | The investigators will collect and store peripheral blood samples from every patient, identify those with high and low fibrosis levels using our described protocol, and then select patients with disproportionately high fibrosis levels given their disease burden. The investigators can test for the level of fibrosis by generating induced pluripotent stem cell-derived cardiomyocytes (iPSC- CMs) from these collected blood samples. These iPSC-CMs will be tested, in vitro, for drug sensitivity, susceptibility to apoptotic stimuli, and the propensity to produce pro-fibrotic cytokine activation- all factors which will help the investigators determine fibrosis levels. | Blood samples drawn once at baseline visit |
| Insulin Sensitivity measured by OGTT | An oral glucose tolerance test with insulin measurement (OGTT) will be performed for all the patients. The investigators will draw blood to determine a fasting glucose measurement, and then the patients will be given a 75 g glucose solution to drink. Blood samples will be collected at serial time points (30 minutes, 60 minutes, 120 minutes) after ingestion of this liquid to determine blood glucose and insulin levels. The OGTT will help investigators determine the patient's degree of insulin sensitivity. | OGTT done at baseline/ first visit |
| Insulin Sensitivity measured by Fasting Lipid Panel | Baseline fasting lipids will be assessed to calculate a TG/HDL-C ratio, which also correlates with the degree of insulin sensitivity or lack thereof. These results will be correlated to the insulin sensitivity assessment performed by the OGTT. | Lipid Panel done at baseline/ first visit |
| Left ventricular volume | Cardiac MRI/ CMR done to noninvasively image heart and determine volume of left ventricle | CMR done at baseline visit |
| Measure | Description | Time Frame |
|---|---|---|
| Collagen turnover assessment | Patients will have blood drawn for serum measurement of propeptides of several procollagens to determine the level of collagen turnover | Blood drawn at baseline visit |
| Endothelial Function |
Not provided
Inclusion Criteria:
- South Asian
Exclusion Criteria:
Not provided
Not provided
South Asians between the age of 20 and 60 who have no active coronary heart disease or other non-ischemic cardiomyopathies
Not provided
| Name | Affiliation | Role |
|---|---|---|
| Rajesh Dash, MD, PhD | Stanford University | Principal Investigator |
| Abha Khandelwal, MD | Stanford University | Study Director |
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| Stanford University | Stanford | California | 94305 | United States |
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
The investigators will probe individual patient risk based on initial cardiac fibrosis measurements. In insulin resistance, the degree of fibrosis may be out of proportion to disease severity, pointing to a genetic predisposition for increased cardiac cell dropout (i.e. apoptosis) and replacement fibrosis. To address this idea, the investigators will collect and store peripheral blood samples from every patient, identify those with high and low fibrosis levels, and then select patients with disproportionately high fibrosis levels given their disease burden. Induced pluripotent stem cell-derived cardiomyocytes (iPSC- CMs) will then be generated. The iPSC-CMs will be tested, in vitro, for drug sensitivity, susceptibility to apoptotic stimuli, and the propensity to produce pro-fibrotic cytokine activation. In this manner, the investigators will study the individual patient's myocardial cell features that increase the risk of cardiac fibrosis and the subsequent adverse outcomes that ensue.
| Left ventricular mass |
Cardiac MRI/ CMR done to noninvasively image heart and determine mass of left ventricle |
| CMR done at baseline visit |
| Ejection fraction % | Cardiac MRI/ CMR done to noninvasively image heart and determine ejection fraction | CMR done at baseline visit |
| Myocardial tagging for strain analysis | Cardiac MRI/ CMR done to noninvasively image heart and assess ventricular function through myocardial tagging. By modulating the magnetization gradient of the MRI prior to acquiring images, any parts of the heart which are not contracting can be identified. These images will be analyzed via strain analysis for such abnormalities in function | CMR done at baseline visit |
| Assessing diffuse fibrosis via T1 mapping | A CMR technique called T1 mapping will be performed to calculate level of extracellular volume (ECV), which helps with the quantification of diffuse fibrosis | CMR done at baseline visit |
| Assessing level of edema via T2 mapping | A CMR technique called T1 mapping will be performed assess amount of edema in the heart | CMR done at baseline visit |
The investigators will also measure endothelial function using the endoPAT device, which employs noninvasive measurement of finger arterial pulsatile volume changes as a measure of endothelial function. This test takes approximately 15 minutes and is noninvasive.
| 15 minute procedure done at baseline visit |
| Urine test for albumin levels | 24 Hour urine test for assessment of albumin levels | One urine test done at baseline visit |
| Urine test for creatinine levels | 24 Hour urine test for assessment of creatinine levels | One urine test done at baseline visit |
| ID | Term |
|---|---|
| D009202 | Cardiomyopathies |
| D007333 | Insulin Resistance |
| D003920 | Diabetes Mellitus |
| ID | Term |
|---|---|
| D006331 | Heart Diseases |
| D002318 | Cardiovascular Diseases |
| D006946 | Hyperinsulinism |
| D044882 | Glucose Metabolism Disorders |
| D008659 | Metabolic Diseases |
| D009750 | Nutritional and Metabolic Diseases |
| D004700 | Endocrine System Diseases |
Not provided
Not provided