RESUMO
Insulin like growth factor-1 has incriminated as a key role in the pathogenesis of immediate and late diabetic complications. IGF-1 concentration changes either in blood or renal tissues may contribute to the pathogenesis of diabetic nephropathy. The objective of this study is to compare the level of urinary and serum IGF-1 in diabetics and non-diabetic subjects and to predict the relation between IGF-1 and development of diabetic nephropathy. It is released from various organs with the liver being the most important source. The present study assessed urinary and serum 1GF-1 in 24 patients, twelve of them are diabetics with microalbuminuria and twelve of them are diabetic with overt nephropathy and also in twelve control non-diabetic subjects of matched age and sex. Every group contain six males and six females, the differentiation between diabetic groups was based on Cambur-lll and Micral-l tests. The immunoassay of IGF-1 is a "sandwich type assay" by using mouse monoclonal antibodies directed against two different epitopes of IGF-1 which are employed in the kit. Serum IGF-1 showed statistically non-significant difference between the three test groups. Urinary IGF-1 showed marked significant difference between the three test groups. The highest value was in overt nephropa thy group [group III] [0.800:0.100 pg/ ml], then microalbuminuria diabetic group [group II] [0.408:0.007 pg/ml]. The lowest value was found in control group [group I] [0.189+0.0028 pg/ml], p value <0.01 when comparing group III with group I. Also urinary IGF-1 showed a positive correlation with the diabetic duration, mean blood pressure and serum creatinine level [P<0.001]. These results indicate that urinary 1GF-1 may reflect the important role of tissue IGF-1 in the pathogenesis and development of diabetic kidney disease
RESUMO
The most common type of diabetes in the elderly is type 2 diabetes which has a hereditary association and is aggravated by obesity and diabetogenic drugs; its prevalence increase with aging from 6% among those aged 45-54 years to more than 20% among those aged 75 years or older. Glucagon like peptide-I [GLP-I] is a hormone secreted from gut endocrine cells in response to nutrient ingestion and plays multiple roles in metabolic homeostasis as stimulation of glucose-dependent insulin secretion and insulin biosynthesis, inhibition of glucagon secretion and gastric emptying and inhibition of food intake. The objective of this study is to compare between the levels of GLP-I in diabetics and non diabetic elderly and to predict the possible role of GLP-I in the development of type 2 diabetes mellitus in the elderly. The presentawork assessed the postprandial serum level of GLP=I in 30 elderly patients with type 2 diabetes mellitus 15 males and 15 females Their age'ranged between 65-74 years. Their mean age is 68.27 years in comparison to 30 control non-diabetic elderly of matched age and sex. The radioimmunoassay of GLP-I is based upon the competition between labeled I 125 peptide and unlabeled peptide binding to a limited quantity of GLP-I antibody, as the concentration of standard or unknown in the reaction increases the amount of I 125 peptide able to bind to the antibody decrease. By measuring the amount of I 125 peptide bound as a fraction of the concentration of the unlabeled peptide in standard reaction mixture the standard curve is constructed and from which the concentration of the peptide in the samples can be determined. Serum GLP-I shows a statistically marked significant decrease in diabetic elderly group when compared to the control group with mean value of [7.56 ng/ml] in diabetic group versus [16.99 ng/ml] in control group P value <0.001 with no gender difference in the diabetic group with mean value of [8.24 ng/ml] in males diabetic versus [6.88 ng/ml] in females diabetic with P value 0.20. Also there is a highly significant negative correlation between GLP-I and insulin and glucagon levels in diabetic group with P value <0.001. These results indicate that GLP-I decrease in elderly type 2 diabetics and this decrease may be a cause of the high prevalence of type 2 diabetes in the elderly population