January 12, 2006

Data from Diabetes Prevention Program Now Available through Repository

Researchers worldwide now have free access to data from the Diabetes Prevention Program (DPP), a landmark clinical study sponsored by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). The DPP showed that people at high risk for developing type 2 diabetes can often prevent or delay the disease by losing 5 to 7 percent of their weight through increased physical activity and a lower-calorie diet. The data are available through NIDDK's Central Repository, which also houses data and, in some cases, biosamples collected in other large clinical trials funded by the Institute.

"The research community is just beginning to tap into this tremendous resource, which NIDDK created to expand the usefulness of the large clinical studies it has funded," says NIDDK's Rebekah Rasooly, Ph.D., who oversees the repository.

The NIDDK Central Repository consists of three parts:

• a database repository that gathers, stores, and distributes datasets from clinical studies. The repository also helps data coordinating centers to prepare databases and incremental datasets for archiving, and provides assistance in querying stored databases.
• a biosample repository, which gathers, stores, and distributes biological samples from studies. The repository collects and stores sample collections from new, ongoing, and completed studies.
• a genetics repository, which receives and processes blood samples to allow genetic analyses. This repository creates immortalized cell lines, or cryopreserves nucleate cells for future immortalization, and prepares DNA from whole blood, cryopreserved cells and cell lines.

All information identifying study participants has been removed from the data and biosamples.

Data and, in some cases, biosamples from the following trials are now available:

• The Diabetes Prevention Program (DPP) showed that intensive lifestyle changes-losing 5 to 7 percent of weight through increased physical activity and a reduced calorie diet-prevented or delayed the onset of type 2 diabetes by 58 percent in people at high risk for the disease. The DPP also showed that metformin, an oral diabetes drug, reduced the onset of type 2 diabetes by 31 percent.
• The Diabetes Prevention Type 1 (DPT-1)trial determined that low-dose insulin injections do not delay or prevent type 1 diabetes in people who have a high risk of developing the disease within 5 years. A second DPT-1 trial showed that insulin taken orally does not delay or prevent type 1 diabetes in people at moderate risk of developing the disease in 5 years. To identify people at risk, researchers screened nearly 90,000 relatives of people with type 1 diabetes for islet cell antibodies (ICAs), one marker of risk. About 3.5 percent of screened relatives had ICAs in their blood, making them eligible to participate in the study.
• The NIDDK Liver Transplantation Database (LTD) and the 5-year follow up study of the original cohort. This database contains information collected in a 7-year prospective study of 916 liver transplant recipients out of 1,563 candidates evaluated for liver transplantation at three major transplant centers in the United States.
• The National Analgesic Nephropathy Study (NANS) examined the relationship between the use of analgesics and end stage renal disease to learn if the non-contrast CT scan is able to detect analgesic nephropathy (AN). In this study, CT scans were performed in more than 200 ESRD patients, who completed a detailed questionnaire. The questionnaire was also completed by more than 200 matched non-ESRD controls.
• The Modification of Diet in Renal Disease (MDRD) Study was a multicenter clinical study designed to determine whether: 1) restriction of dietary protein and phosphorus, and/or 2) reduction of blood pressure below 140/90 reduces the rate of progression of chronic renal disease irrespective of the nature of the primary underlying process. Patient with renal disease were screened, and the severity of their disease was assessed by measuring their glomerular filtration rate. Patients were randomized to either normal diets, a low protein/low phosphorus diet, or a very low diet supplemented with keto amino acids. They were also randomized to a regimen to reduce blood pressure. Diabetics taking insulin were excluded from this trial.
• The Interstitial Cystitis Data Base (ICDB) was a prospective, multicenter clinical study. Interstitial cystitis is a poorly understood condition that causes severe, chronic bladder and pelvic pain, urinary frequency, and dysuria, more frequently in women. Clinical, demographic, and pathological data were collected, including bladder biopsies. The study tracked Interstitial Cystitis treatments and symptoms in patients and provided numerous treatment codes to describe medical and nonmedical interventions. ICDB data has allowed a clearer classification of Interstitial Cystitis and better clinical trial design for the study of this disease.

To access the data and materials stored in the repository, researchers apply to NIDDK using the instructions explained on the repository's website. An NIDDK-established panel of outside experts reviews all requests, which are judged on criteria such as the researcher's qualifications and the research environment, the design, significance, and appropriateness of the proposed research, and ethical considerations.

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CONTACT: Rebekah Rasooly
NIDDK
301-594-6007