The overriding objective of DREAM is to conduct a prospective longitudinal (36 months) observational clinical study to investigate the incidence, etiology, and pathophysiology of diabetes mellitus (DM) following acute pancreatitis (AP).

The DREAM investigators will conduct dynamic metabolic testing that includes oral glucose tolerance testing (OGTT), mixed meal tolerance testing (MMTT), and frequently sampled intravenous glucose tolerance testing (FSIGTT). These tests will increase the sensitivity for DM diagnosis (with OGTT) and to assess beta cell function and other pancreatic and enteroendocrine hormones involved in maintaining glucose homeostasis (OGTT, MMTT and FSIGTT). The DREAM research hypotheses are as follows.

1. There is a cumulative increase in the risk of any type of DM after an episode of AP, and the development of DM after AP is influenced by several patient and disease-related factors (e.g. age, etiology, disease severity).
2. After AP is clinically resolved, there is ongoing subclinical beta cell damage that predisposes to delayed-onset of DM.
3. AP triggers an altered immune state in a subset of individuals that predisposes to islet autoimmunity and DM.

Inclusion Criteria:

• Diagnosis of acute pancreatitis (AP) 0-90 days prior to enrollment date
• Participant fully understands and is able to participate in all aspects of the study, including providing informed consent, completion of case report forms (CRFs), telephone interviews, metabolic testing, and planned longitudinal follow-ups

Exclusion Criteria:

• Diagnosis of definite chronic pancreatitis (CP) at enrollment based on either of the following criteria met by computed tomography (CT) scan (including non-contrast enhanced) or Magnetic resonance Imaging (MRI) or Magnetic Resonance Cholangiopancreatography (MRCP): (a) Parenchymal or ductal calcifications on CT scan (after excluding the possibility that calcifications are vascular); (b) Intraductal filling defects suggestive of calcifications on MRI and/or MRCP
• Potential participants with post-endoscopic retrograde cholangiopancreatography (post- ERCP) AP who are hospitalized for <48 hours.
• Prior (i.e., before enrollment) direct endoscopic necrosectomy of the pancreas or percutaneous necrosectomy or drainage of necrotic collection(s). Participants who require this during follow-up will remain in the study
• Pancreatic tumors, including ductal adenocarcinoma, neuroendocrine tumors, and metastasis
• Confirmed or suspected cystic tumor associated with main pancreatic duct dilation, or believed to be the cause of AP (in the site-PI's judgement)
• Prior pancreatic surgery, including, but not limited to: distal pancreatectomy, pancreaticoduodenectomy, pancreatic necrosectomy, Frey procedure
• Use of disallowed concomitant medications within 30 days prior to enrollment. A comprehensive list of disallowed medications will be included and routinely updated in the study's Manual of Procedures
• Severe systemic illness that in the judgement of the investigative team will confound outcome assessments of DM and immunological outcomes or pose additional risk for harms, including: history of solid organ transplant, acquired immunodeficiency syndrome (AIDS), active treatment for cancer (except non-melanoma skin cancer) within 12 months prior to enrollment, chronic kidney disease with estimate glomerular filtration rate (eGFR) < 30 or on dialysis prior to AP, and cirrhosis (based on imaging or biopsy), or any other medical condition that in the opinion of the site-PI carries a life expectancy of <12 months.
• Known pregnancy at the time of enrollment. Participants who become pregnant during follow-up will remain in the study, but may have modified study assessments for safety
• Incarceration
• Any other condition or factor that would compromise the participant's safety or the scientific integrity of the study

Patients hospitalized for acute pancreatitis

Data from final locked datasets will be made available to other researchers outside the DREAM investigative team. The plan for data sharing incorporates a strategy that recognizes the importance of protecting participants' rights to individual privacy and is compliant with HIPAA regulations and NIH requirements (https://grants.nih.gov/grants/policy/data\_sharing/).

The data will become available one year after publication of the primary manuscript of the DREAM study. The data will be available indefinitely at the NIDDK Central Repository.

Instructions for requesting data from the NIDDK Central Repository appear at the following web site:

https://repository.niddk.nih.gov/pages/overall\_instructions/