OBJECTIVEPancreas size is reduced in patients at type 1 diabetes onset and in autoantibody (AAB)-positive donors without diabetes. We sought to determine whether pancreas volume (PV) imaging could improve understanding of the loss of pancreas size in first-degree relatives (FDRs) of patients with type 1 diabetes. We also examined relationships among PV, AAB status, and endocrine and exocrine functions.
RESEARCH DESIGN AND METHODSWe conducted a cross-sectional study that included five groups: AAB 2 control subjects (no diabetes and no firstor second-degree relatives with type 1 diabetes) (N = 49), AAB 2 FDRs (N = 61), AAB + FDRs (N = 67 total: n = 31 with a single positive AAB [AAB + single] and n = 36 with multiple positive AABs [AAB + multiple]), and patients with recent-onset type 1 diabetes (<1 year) (N = 52). Fasting subjects underwent 1.5T pancreatic MRI, and PV and relative PV (RPV) (PV-to-BMI ratio) were analyzed between groups and for correlations with HbA 1c , C-peptide, glucose, and trypsinogen.
RESULTSAll FDR groups had significantly lower RPV adjusted for BMI (RPV BMI ) than control subjects (all P < 0.05). Patients with type 1 diabetes had lower RPV BMI than AAB 2 FDR (P < 0.0001) and AAB + multiple (P £ 0.013) subjects. Transformed data indicated that trypsinogen levels were lowest in patients with type 1 diabetes.
CONCLUSIONSThis study demonstrates, for the first time, all FDRs having significantly smaller RPV BMI compared with AAB 2 control subjects. Furthermore, RPV BMI was significantly lower in patients with recent-onset type 1 diabetes than in the AAB 2 FDR and AAB + multiple groups. As such, RPV BMI may be a novel noninvasive biomarker for predicting progression through stages of type 1 diabetes risk. This study highlights the potential paracrine relationships between the exocrine and endocrine pancreas in progression to type 1 diabetes in subjects at risk.Despite advances in medical diagnosis and treatment, type 1 diabetes remains one of the costliest diseases in the U.S. in terms of health care dollars spent for diabetesrelated costs (1). Immunotherapy-based intervention trials carried out in patients with new-onset type 1 diabetes have demonstrated potential for short-term benefit (e.g., anti-CD20, anti-CD3, and cytotoxic T-lymphocyte-associated antigen 4 Ig) but have failed to demonstrate long-term efficacy (2,3). The inability to provide long-term preservation of b-cell function or prevent type 1 diabetes may stem from unanswered