The NIDDK Central Repository stores biosamples, genetic and other data collected in designated NIDDK-funded clinical studies. The purpose of the NIDDK Central Repository is to expand the usefulness of these studies by allowing a wider research community to access data and materials beyond the end of the study.

NIDDK Central Repositories are two separate contract funded components that work together to store data and samples from significant, NIDDK funded studies. First component is Biorepository that gathers, stores, and distributes biological samples from studies. Biorepository works with investigators in new and ongoing studies as realtime storage facility for archival samples.Second component is Data Repository that gathers, stores and distributes incremental or finished datasets from NIDDK funded studies Data Repository helps active data coordinating centers prepare databases and incremental datasets for archiving and for carrying out restricted queries of stored databases. Data Repository serves as Data Coordinating Center and website manager for NIDDK Central Repositories website.

While there are hypotheses and preliminary data as to the etiology of type 1 diabetes (T1D), the data are often limited by imprecise assessment of exposure, recall bias, failure to account for genetic susceptibility, failure to assess exposures at very early ages, or the inability to follow a sufficient sample of children long-term with high intensity. The Environmental Determinants of Diabetes in the Young (TEDDY) study is a multicenter prospective cohort study that was established in response to these gaps in understanding of T1D. The primary objectives of the study include identifying environmental factors—such as infectious agents, dietary factors, and psychosocial factors—that trigger or protect against the development of islet autoimmunity and T1D and examining genetic-environmental interactions to investigate interactive effects that contribute to T1D.

The TEDDY study was designed to follow children with and without a family history of T1D to understand the environmental factors that contribute to the disease. Newborn children younger than 4 months were screened for high-risk HLA alleles, and those with qualifying haplotypes were eligible for follow-up. Information is collected on medical information (infections, medication, immunizations), exposure to dietary and other environmental factors, negative life events, family history, tap water, and measurements of psychological stress. Biospecimens, including blood, stool, urine, and nail clippings, are taken at baseline and follow-up study visits. The primary outcome measures include two endpoints—the first appearance of one or more islet cell autoantibodies (GADA, IAA, or IA-2A), confirmed at two consecutive visits, and development of T1D. The cohort will be followed for 15 years, or until the occurrence of one of the primary endpoints.

The TEDDY data currently available include screening phase data, baseline phase data, study phase clinical data, and multiple analysis datasets. Data collection began in 2004 and is still on-going.

The Diabetes Prevention Program (DPP) is a clinical trial that investigated whether modest weight loss through dietary changes and increased physical activity or treatment with the oral diabetes drug metformin (Glucophage) could prevent or delay the onset of type 2 diabetes in high risk individuals with prediabetes.

The study enrolled overweight persons with elevated fasting and post-load plasma glucose concentrations. Participants were randomized to placebo, metformin (850 mg twice daily), or a lifestyle-modification program with the goals of at least a 7 percent weight loss and at least 150 minutes of physical activity per week. The primary outcome measure was development of diabetes, diagnosed on the basis of an annual oral glucose-tolerance test or a semiannual fasting plasma glucose test, according to the 1997 criteria of the American Diabetes Association: a value for plasma glucose of 126 mg per deciliter (7.0 mmol per liter) or higher in the fasting state, or 200 mg per deciliter (11.1 mmol per liter) or higher two hours after a 75-g oral glucose load. Participation in DPP continued after a diagnosis of diabetes was made, although study medication was discontinued and participants were sent to their local primary care provider for treatment of diabetes once fasting glucose was > 140 mg/dl.

Results showed that both lifestyle changes and treatment with metformin reduced the incidence of diabetes in persons at high risk compared with placebo. Furthermore, the lifestyle intervention was more effective than metformin in preventing the onset of diabetes.

Supplemental measurements were collected using biospecimens that were obtained during the original DPP clinical trial. These measurements included antibodies, biomarkers, hormones, and vitamin D levels to assess the relationships between sex hormones, diabetes risk factors, and the progression to diabetes. The supplemental data showed that sex hormones were associated with diabetes risk in men, but these associations were not found in women. Furthermore, obesity and glycemia were more important predictors of diabetes risk than sex hormones.

This dataset tracks the updates made on the dataset "NIDDK Central Repository" as a repository for previous versions of the data and metadata.

Teen-LABS conducted coordinated clinical, epidemiological, and behavioral research focused on adolescent bariatric surgery. The study developed common clinical protocols and a bariatric surgery database for the purpose of collecting information from participating clinical centers that performed bariatric surgery on teenagers. Outside of investigating surgical outcomes, Teen-LABS sought to better understand the etiology, pathophysiology, and behavioral aspects of severe obesity in youth as well as how severe obesity impacts humans over time. Participants were recruited from six clinical centers and underwent bariatric surgery. Pre- and post-surgery data and biospecimens were obtained at pre-determined points.

The Chronic Renal Insufficiency Cohort (CRIC) Study is an observational study that examined risk factors for progression of chronic renal insufficiency (CRI) and cardiovascular disease (CVD) among CRI patients. The study enrolled adults aged 21 to 74 years with a broad spectrum of renal disease severity, half of whom were diagnosed with diabetes mellitus. Subjects underwent extensive clinical evaluation at baseline and at annual clinic visits and via telephone at 6 month intervals. Data on quality of life, dietary assessment, physical activity, health behaviors, depression, cognitive function, health care resource utilization, as well as blood and urine specimens were collected. Measures of kidney function and occurrence of new and worsening CVD are the primary outcomes, among others.

Data from the recruitment and follow-up phases through Phase 3. Additionally, the data package includes variables related to APOL1, Echocardiogram, Electrocardiogram, and censored composite and individual outcomes. The data package includes data through 2021.

Retinal images for CRIC participants are not included in the package, but are available upon request.

The FHN Daily Trial was a randomized controlled trial which recruited subjects from dialysis units associated with designated Clinical Centers in the U.S. and Canada and followed for 1 year. Subjects were randomized to either conventional hemodialysis delivered for at least 2.5 hours (typically 3 to 4 hours), 3 days per week (120 patients), or to more frequent hemodialysis delivered for 1.5 - 2.75 hours, 6 days per week (125 patients). The study had two co-primary outcomes: 1) a composite of mortality with the change over 12 months in left ventricular mass by magnetic resonance imaging, and 2) a composite of mortality with the change over 12 months in the SF-36 RAND physical health composite (PHC) quality of life scale.

Note: The available data do not contain digital raw ECG recordings. Please review the Data Dictionary for a listing of available datasets and variables.

The Clinical Outcomes Research Initiative (CORI) was established in 1995 under the American Society for Gastrointestinal Endoscopy (ASGE) to study outcomes of gastrointestinal (GI) endoscopic procedures in clinical settings. Physicians participating in the CORI consortium produce GI endoscopy reports using an electronic health record developed specially for the project. CORI practice sites include hospitals, ambulatory care centers, private practices, universities, and Veteran's hospitals. The practice data are stripped of most patient and physician identifiers before transmitting to a central data repository, where they are tested for completeness and accuracy. Data from all participating practices are merged and stored in the National Endoscopic Database (NED).

Data from the NED has been analyzed to examine endoscopic practice patterns, including endoscopic utilization, frequency and severity of endoscopic findings, and endoscopic treatment and medical management. The data also serve as a resource to develop research hypotheses and to support quality measure reporting. CORI data has already been utilized to support many research initiatives, many of which have resulted in publications in medical journals and presentations at GI conferences.

In addition to availability in through the CORI consortium, the data collected in the NED since 2000 is been contributed to the NIDDK Repository and is available for request through the NIDDK Repository site.

The current data package contains data from the v3 warehouse from 2000 through 2010.

List of repositories evaluated in this study.

The Consortium for Radiologic Imaging Studies of Polycystic Kidney Disease (CRISP) was established to develop and implement studies to test whether imaging techniques can provide accurate and reproducible markers of progression of renal disease in patients with polycystic kidney disease. Autosomal-dominant polycystic kidney disease (ADPKD) is characterized by gradual renal enlargement and cyst growth prior to loss of renal function; however, standard radiographic imaging has not provided the resolution and accuracy necessary to detect small changes in renal volume or to reliably measure renal cyst volumes. The CRISP cohort study longitudinally observed ADPKD individuals using high-resolution magnetic resonance (MR) imaging to determine if change in renal and cyst volumes can be detected over a short period of time, and if they correlate with decline in renal function early in disease.

Patients who were diagnosed with ADPKD and had a creatinine clearance of at least 70 mL/min were enrolled. Standardization studies were conducted at each participating clinical center. After, in the full-scale protocol, participants underwent standardized MR renal imaging, comprehensive clinical evaluation, evaluation of renal iothalamate clearance, and determination of 24-hour urinary albumin and electrolyte excretion. Stereology was used from T1-weighted images to quantify renal volume, and region-growing thresholding was used from T2-weighted images to determine cyst volume.

The CRISP cohort was also analyzed by molecular analysis. Given the high level of unclassified variants (UCV) in patients with ADPKD, the purpose of the molecular analysis was to systematically classify UCVs in the PKD1 and PKD2 genes.

The current data package contains data through the CRISP 3 cycle as well as CRISP allele frequency data.

MRI images for CRISP participants are not included in the package, but are available upon request.

Guiding principles for OFCT used in this study to develop the assessment instrument.

Questions and properties used for the final interview, the table shows the question order (Q#), the text of the question posed in the interview (Question text), possible answers (Answers), whether or not the question is conditional (“C”), the dependencies of conditional questions (D) and the principle(s) the question is meant to cover (P).

Ratings for each OFCT property and flag.

The Type 1 Diabetes Genetics Consortium (T1DGC) was an international, multicenter program organized to promote research to identify genes and alleles that determine an individual's risk for type 1 diabetes. The program had two primary goals: (1) to identify genomic regions and candidate genes whose variants modify an individual’s risk of type 1 diabetes and help explain the clustering of the disease in families and (2) to make research data available to and establish resources that can be used by the research community. The T1DGC assembled a resource of affected sib-pair families, parent-child trios, and case-control collections with banks of DNA, serum, plasma, and EBV-transformed cell lines. In addition to T1DGC-recruited ASP families, the T1DGC recruited trio families from ethnic groups with lower prevalence of type 1 diabetes. The T1DGC also welcomed the inclusion of earlier ascertained case-control collections (from the UK, Denmark, etc.). Research with T1DGC data has included genome-wide linkage scans, evaluation of the human major histocompatibility complexes, examination of published candidate genes for type 1 diabetes, and examination of autoimmune disease genes and those affecting β-cell function in type 2 diabetes.

In 2007, the T1DGC incorporated over 7,000 cases from the UK (the JDRF/WT case series, aka GRID). GRID samples are available here, and data from dbGaP, the European Genome-phenome Archive (EGA) and data and documentation at the JDRF/WT DIL.

The Diabetes Control and Complications Trial (DCCT) was a multicenter, randomized clinical trial designed to compare intensive with conventional diabetes therapy with regard to their effects on the development and progression of the early vascular and neurologic complications of type 1 insulin-dependent diabetes mellitus. The DCCT study involved 1,441 participants, ages 13 to 39, with type 1 diabetes and either no or minimal background retinopathy. Participants were required to have had diabetes for at least 1 year but no longer than 15 years.

Once enrolled, patients were randomized to receive standard therapy, consisting of not more than two injections of insulin per day, or intensive therapy, consisting of either subcutaneous insulin infusion by pump or at least three subcutaneous injections of insulin daily, targeting near-normal glycemia. Both groups received the same dietary management and education program. Blood glucose and hemoglobin A1c measurements were used as primary indicators of metabolic control. The primary outcome measure was diabetic retinopathy. Other outcome measures included diabetic nephropathy, diabetic neuropathy, and cardiovascular events or their known or putative risk factors. The DCCT study found that intensive therapy showed beneficial effects on retinopathy, nephropathy, and neuropathy when compared with conventional therapy.

Following these findings, the Epidemiology of Diabetes Interventions and Complications (EDIC) study was initiated as follow-up to examine the long-term effects of the original DCCT interventions on diabetic complications such as cardiovascular events and advanced retinal and renal disease. Over 90 percent of participants from the DCCT study were followed by the EDIC study. Similar to the DCCT study, glycosylated hemoglobin values, fasting lipid levels, serum creatinine values, and other risk factors for cardiovascular disease were measured at different intervals for participants. Cardiovascular complications were assessed with standardized means and classified by an independent committee. The EDIC study has found that intensive diabetes therapy reduced risk of cardiovascular disease in patients with type 1 diabetes and that the differences in outcomes between the intensive and conventional therapy groups persist after long-term study.

Data from the DCCT/EDIC study up to June 2017 (the end of EDIC Year 24) are available from the Repository. GWAS data may be requested through dbGAP.

TrialNet is a network of 19 clinical centers worldwide that conducts research on the study, prevention, and early treatment of type 1 diabetes (T1D). The TrialNet Pathway To Prevention (TN01) is a screening and monitoring study that was established to provide a source of subjects for enrollment into prevention trials. In addition, the prospectively followed cohort is used to gain new insights into the natural history of pre-type 1 diabetes in patients with increased risk for the disease. The primary aim of the study is to identify subjects for TrialNet prevention and investigation trials, but can also be used for assessing the predictive value of existing and novel risk markers of T1D, and for examining the demographic, immunologic, and metabolic characteristics of individuals at risk for developing T1D.

Participants who are unaffected by T1D but who had a family member with TID and hence increased risk for developing the disease are eligible for enrollment. Screened subjects are tested for pancreatic autoantibodies (glutamic acid decarboxylase, insulin, ICA-512) using a blood screening test. Participants with at least one positive tests for any of the antibodies are eligible for confirmatory autoantibody measurements, and metabolic testing including oral glucose tolerance tests (OGTTs). Subjects under age 18 are re-screened annually, and subjects with some risk for disease can be enrolled in prevention trials or followed prospectively.

Data collected on patients recruited through 2020 are available from the Repository.

Lower urinary tract dysfunction (LUTD) is a condition related to the functions and/or structures of the lower urinary tract. LUTD affects both men and women, and becomes more common and frequent with age. Patients tend to exhibit a range of lower urinary tract symptoms (LUTS), but there has been a lack of understanding regarding which biological and psychosocial factors cause the symptoms to manifest and worsen. As a result, treatment and management methods for LUTS and LUTD have been unsatisfactory.

The Symptoms of Lower Urinary Tract Dysfunction Phenotyping Study (LURN) was established to gain a better understanding of lower urinary tract symptoms in an effort to improve the lives of those with LUTD. LURN participants were enrolled at multiple sites within the United States. Participants were assigned to one of four subgroups, based on their symptoms, the outcomes of clinical assessments, and other characteristics. Biological samples were collected from study participants and participants were required to complete certain assessments and examinations at standard time-points during the study period.

MRI images for LURN participants are not included in the package, but are available upon request.

Short-term studies have shown numerous benefits of weight loss in overweight or obese patients, including improvements in glycemic control, risk factors for cardiovascular disease, quality of life, and other obesity-related coexisting illnesses. The Look AHEAD study was designed to test whether weight loss similarly improved cardiovascular morbidity and mortality in patients with type 2 diabetes. The study is a multicenter, randomized clinical trial that examines the long-term effects of an intensive lifestyle intervention program designed to achieve and maintain weight loss by decreased caloric intake and increased physical activity.

Eligible patients with type 2 diabetes and a body-mass index (BMI) of 25.0 or more were enrolled and randomly assigned either to participate in an intensive lifestyle intervention (intervention group) or to receive diabetes support and education (control group). The intensive lifestyle intervention, which included both group and individual counseling sessions, was aimed at achieving and maintaining weight loss of at least 7% by focusing on reduced caloric intake and increased physical activity. The diabetes support and education program featured sessions focusing on diet, exercise, and social support. Both the intervention and control programs occurred with decreasing frequency as the trial progressed. The primary outcome measure is the first occurrence of a composite cardiovascular outcome, which consists of death from cardiovascular causes, nonfatal myocardial infarction, nonfatal stroke, and hospitalization for angina. Participants will be followed for a planned period of 13.5 years.

An ancillary study, Look AHEAD Brain, was conducted to assess whether participation in the 10-year lifestyle intervention, as part of Look AHEAD, had an impact on white matter hyperintensity and loss of brain tissue among individuals with type 2 diabetes. A subset of Look AHEAD study participants underwent standardized brain magnetic resonance imaging in conjunction with tests assessing cognitive function 10-12 years post-randomization.

The Look AHEAD intensive lifestyle intervention ended in September, 2012. Participants continued to be followed to determine the long-term effects of the intervention on health outcomes.

The Look AHEAD Continuation Study (Look AHEAD-C) builds on the Look AHEAD study to determine the long-term impact of an intensive lifestyle intervention on 1) physical function and mobility disability, and 2) cognitive function and cognitive impairment. Collection of cognitive function measures began in Year 8 of the study and continued through Year 13.

The current data package contains data through the end of the post intervention program.

The Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network was established to focus on a broader approach to the study of Interstitial Cystitis (IC)/Painful Bladder Syndrome (PBS) in men and women, and Chronic Prostatitis (CP)/Chronic Pelvic Pain Syndrome (CPPS) in men. Participants with some form or symptoms of IC or CP were asked to join the Trans-MAPP Epidemiology and Phenotyping (EP) Study. Participants with no Urologic Pelvic Pain Syndromes as well as participants with specific conditions (Fibromyalgia (FM), Irritable Bowel Syndrome (IBS), Chronic Fatigue Syndrome (CFS)) were recruited for the Trans-MAPP Control Study. These participants were a reference/control group for the Trans-MAPP EP Study.

Full study data are available for request.

MRI images for MAPP I participants are not included in the package, but are available upon request.