Association of some Amino Acids in Serum with Insulin Secretion among Sudanese patients with type 2 Diabetes Mellitus-study in Khartoum State

Abstract

A great number of people all over the world suffer from diabetes. Understanding the mechanisms by which amino acids regulate insulin secretion in vivo may reveal novel sites for targeting drugs for the therapy of type 2 diabetes in the future. A descriptive analytical cross-sectional and hospital based study was done. The objectives of this study were to determine in the levels of selected amino acids in patients with diabetes type 2 and to measure the serum levels of insulin in Sudanese patients with diabetes mellitus type 2. Samples were collected from different diabetes centers and hospitals in Khartoum State from October 2012 to January 2014. A total of 167 Sudanese patients with type2 diabetes mellitus were enrolled in this study with age ranged from 20 to 80 years and 47 healthy volunteers (age and sex matched) were involved as control. The study population was divided into males (n =116) and females (n = 98). Venous blood samples were obtained in heparinised tubes after an overnight fast from each participant. Whole blood was put in separate tubes for HBA1C test by ion exchange resin chromatography. Plasma was separated for running the insulin test using ELISA Plasma protein was precipitated by 20% sulfosalicylic acid, centrifuged at 4°C for 15 min at 12000 rpm and the clear supernatant was kept at -80°C until analysis. Plasma glutamate, alanine, luecine, arginine, were determined by automated ion-exchange chromatography with ninhydrin using an amino acid analyzer. Results showed significantly higher levels ofalanine(mean=494.39±242.19)(pvalue=0.000<0.05),leucine(mean=137.54±46.42),(pvalue=0.010<0.05),glutamate(mean=129.34±65.90),(pvalue=0.000<0.05),arginine (Mean=88.66±31.13) (P-value =0.000< 0.05)in diabetic patients. Significantly higher levels of alanine (mean=500.61±235.91) (p-value=0.018<0.05), insignificant increase in leucine (mean=136.31±44.75)(p-value=0.068>0.05),significant increase in glutamate(mean=132.41±63.01) (p-value=0.007<0.05),insignificant increase in arginine (mean=88.28±30.79) (p-value=0.082>0.05) were seen among female diabetic patients. Insulin level was significantly high among the diabetic patients (mean=15.96±2.52) (p-value =0.000<0.05), and was higher in females (mean=13.14±4.12)(p-value =0.000<0.05) than male,. HbA1C levels were significantly increased in diabetic patients (mean=8.97±1.53) (p-value =0.000<0.05), compared to control group, and was significantly high among female diabetic patients (mean=9.27±1.74) (p-value VI =0.005<0.05) compared to male diabetic patients. Body Mass Index (BMI) was significantly higher in patients with diabetes mellitus type2 (mean=25.18±3.64)) (p-value =0.005<0.05) and was significantly high among female diabetic patients (mean=25.59±3.97) (p-value =0.005<0.05) compared to male diabetic patients. . In this study some of the known effects of the nutritional compounds on insulin secretion and β-cell metabolism were reviewed. Understanding the molecular mechanisms by which glucose, amino acids regulate insulin secretion may identify novel targets for future diabetes therapies. Although, there is a growing evidences suggesting the beneficial effects of nutrients such as amino acids for the treatment of diabetes. More research is needed to investigate and identify the potential effects of individual nutrient (specific amino acid) supplementation in human clinical trials. In addition, nutrient supplementation could be more effective in the early steps of β-cell dysfunction and, for this reason; the time of the nutritional intervention could be critical for the treatment of diabetes mellitus.