Mechanisms of Diabetic Kidney Disease in American Indians

Background: \- An ongoing study is looking at American Indians who have kidney problems caused by type 2 diabetes. Kidney disease due to type 2 diabetes is a major problem in American Indians. We previously found that early treatment of kidney disease with losartan was probably beneficial for reducing progression of the disease. Researchers now want to see if these benefits continue to be seen several years after the end of the treatment study. Objectives: \- To study long-term benefit of losartan treatment for diabetic kidney disease in American Indians with type 2 diabetes. Eligibility: \- Participants in the American Indian diabetic kidney disease study (OH95-DK-N037). Design: * Participants will have a physical exam and medical history before starting the study. Blood and urine samples will be collected. * Participants will have a set of tests as part of this study. Those who have severe kidney problems, such as kidney failure, will only have a basic kidney exam with scans. The remaining participants will have a full urine collection and analysis. They will also provide a kidney biopsy. * Treatment will not be provided as part of this study.

* INCLUSION CRITERIA: To be eligible for participation in the study, subjects must meet the following criteria: * Previous enrollment in protocol OH95-DK-N037 or a first-degree relative of an enrollee who is aged greater than or equal to 18 years and has type 2 diabetes. * Willingness, after receiving a thorough explanation of the study, to participate. EXCLUSION CRITERIA: Subjects will be excluded for the following reasons: * Clinically significant disorders of the liver \[cirrhosis, portal hypertension, hepatitis, increased bilirubin (greater than or equal to 1.5 mg/dl), cardiovascular disease (angina pectoris, history of myocardial infarction, left ventricular ejection fraction \