Abstract
Aim:
Classification of diabetes type in adults patients remains difficult. This study was
undertaken to determine the relationship between presence of autoantibodies in the
serum and the result of glucagon stimulation test in non obese patients at aged above
35 years with newly diagnosed diabetes.
Material and methods:
Study involved 52 non obese adults aged 42 years [interquartile range (IQR): 37–46],
with body mass index (BMI) 23.7 kg/m2 (IQR: 21.4–26.2). Presence of autoantibodies to islet cells (ICA), antibodies to
tyrosine phosphatase (IA-2), glutamic acid decarboxylase autoantibodies (anti-GAD)
and plasma fasting and stimulating (6 min after intravenous injection of 1 mg glucagon)
C-peptide level was assessed.
Results:
73.1% subjects had at least 1 of 3 assessed autoantibodies, 26.9% patients were autoantibodies
negative. According to serum C-peptide concentration after stimulation test with glucagon
patients were divided into 2 groups. Receiver Operating Characteristic (ROC) Curve
for determination of an optimal cut-point (C-peptide stimulation above and below 1.6)
was used. In patients with negative stimulation test higher prevalence of 2 (33.3%
vs. 66.7%; p=0.04) or 3 (12.5% vs. 87.5%, p=0.01) positive autoantibodies was noticed
in comparison to patients with positive stimulation test. Multivariate logistic regression
showed that presence of autoantibodies was independently associated with stimulated
C-peptide level (OR 2.3; 95%CI: 1.07–5.28, p=0.03).
Conclusions:
Autoimmune diabetes should be suspected in subjects with lower response of β- cell
in glucagon stimulation test. If the C-peptide do not increase more than 1.6 after
glucagon presence of autoanibodies is more probable.
Key words
autoimmunity - antibodies - diabetes
