Higher cardiometabolic risk in idiopathic versus autoimmune type 1 diabetes: a retrospective analysis.

Background: Idiopathic type 1 diabetes mellitus (IDM) is characterized by an onset with insulinopenia and ketoacidosis with negative β-cell autoimmunity markers and lack of association with HLA. The aim of the study is to compare the clinical and metabolic parameters, the macro and microvascular complications, the adipose tissue dysfunction and the insulin secretion and sensitivity indexes in patients with IDM and autoimmune type 1 diabetes mellitus (ADM) at clinical onset.

Methods: Thirty patients with IDM and 30 with ADM, matched for age and gender, were retrospectively analyzed. BMI, waist circumference, lipids, glycemia, HbA1c, insulin requirement, glutamic oxaloacetic and glutamic pyruvic transaminases (GOT and GPT), glucagon stimulated c-peptide (GSC-pep) test levels, M value during hyperinsulinemic euglycemic clamp and Visceral Adiposity Index (VAI) were obtained from our database.

Results: Patients with IDM showed a significantly higher BMI (p 0.012), WC (p 0.07), VAI (p 0.004), LDL-cholesterol (p 0.027), GOT (p 0.005), GPT (p 0.001), M value (p 0.006) and GSC-pep peak (p 0.036), with concomitant lower HDL-cholesterol (p < 0.001), than patients with ADM. In addition, patients with IDM showed a more marked familial history for diabetes (p 0.005) and a higher percentage of hepatic steatosis (p 0.001), visceral obesity (p 0.032) and hypercholesterolemia (p 0.007) compared to patients with ADM.

Conclusions: Patients with IDM show many metabolic complications at onset, such as visceral obesity, hepatic steatosis and hypercholesterolemia and a higher cardiometabolic risk, than patients with ADM, similarly to patients with type 2 diabetes at onset.