Clinical,biochemical and immunological characteristic of diabetes type I,LADA, diabetes type II,and MODY patients

Right classification of diabetes is important clinical issue. The aim of present study was to compare clinical, biochemical and immunological features, to analyze their practical use and to establish new decision tree which make the distinction between diabetes type 1, LADA, diabetes type 2 and MODY. We studied 97 not obese (mean BMI 26.3 +/- 4.9 kg/m2) patients aged 14 to 70 years, mean age 43 +/- 11.7 years, 53 women, 44 men. Mean duration of diabetes--2.3 +/- 4.3 years. We measured basal and stimulated C-peptide (6 minutes after 1 mg i.v. glucagon) (ELISA) and antibodies titers to glutamic acid decarboxylase--antiGAD65, tyrosine phosphatase-like molecule--IA2 and insulin--IAA (RIA). Autoimmune diabetes (LADA, type 1) was diagnosed with presence of one or more islet antigen antibodies. The highest frequencies had anti-GAD antibodies 33/97 (34%). The most complicated was to sort out group of patients with LADA. Comparison between this group and patients with diabetes type 2 have shown that BMI, co-existence of autoimmune disease, autoimmune markers and basal and stimulated C-peptide level measured at entry for the classification were useful in differentiation. Moreover we observed significantly lower C-peptide basal, stimulated and over basal level in group with MODY diabetes in comparison to diabetes type 2 patients. In the studied group were 5 patients with diabetes type 2 and obesity, in relatively young age. At the end there was one case of ADM (atypical diabetes mellitus). Clinical criteria for the classification of diabetes not always correlated with diagnosis. Autoimmune markers, basal and stimulated C-peptide were useful specially in differentiation between LADA and diabetes type 2 or diabetes type 1. Autoimmune diabetes co-existe with autoimmune disease. Proposed diagnostic scheme take for consideration presence of autoantibodies as well as C-peptide criteria.