Age at the Onset of Type 2 Diabetes Correlates with Phenotype of Low Molecular Weight Protein Tyrosine Phosphatase

Abstract

Several lines of evidence suggests that cytosolic Low Molecular Weight Protein Tyrosine Phosphatase (cLMWPTP), encoded by ACP1 gene, could be a candidate gene for T2D. Previous studies, however, have not found a direct association between enzyme phenotype and susceptibility to the disease but have only found associations with its clinical manifestations. The data reported in present note suggest that in subjects with advancing age a significant direct associations between cLMWPTP and susceptibility to T2D may indeed exist. Two hundred seventy four subjects with T2D from the population of Penne were studied. All patients gave informed verbal consent to participate in the study that was approved by the Sanitary Direction of Hospital. 380 subjects without T2D were studied in the same population as controls. cLMWPTP phenotype was determined by starch gel electrophoresis. Statistical analyses were carried out by SPSS programs. In patients aging more than 67 years at onset of T2D (corresponding to 90° centile of age distribution) the proportion of cLMWPTP phenotype is statistically different from that of patients aging 67 years or less at onset of the disease and from that of controls. Most of the difference is due to ACP1 B and CB phenotypes: B phenotype shows a progressive decrease of frequency with advancing age at the onset while CB shows an increase of frequency with advancing age of onset. Environmental, alimentary and life style factors could anticipate the onset of T2D: these factors may overshadow the effect of cLMWPTP on susceptibility to T2D: this effect seems to emerge in subjects experiencing the disease in advancing age. REsEARch ARticlE