Evaluation of the role of leptin, interleukin-8 (Il-8) and nitric oxide (No) in children with insulin dependent diabetes mellitus (type 1)

The autoimmune nature of insulin dependent diabetes mellitus (IDDM), type 1, is well established. The documentation of altered Th 1/Th 2 balance and the finding of antibodies in the circulation directed against the b-cells can indicate the role of the immune system. The stimulating effect of insulin on leptin expression is well identified. The aim of this study is to investigate the profile and the relationships between leptin, interleukin-8 (IL-8) and nitric oxide (NO) and to reveal their possible role in the development and progression of IDDM. Serum leptin was evaluated using radioimmunoassay (RIA), serum concentration of IL-8 was assayed by enzyme linked immunosorbent assay (ELISA), while serum nitrite level (end product of NO) was determined by Griess reaction. The study was carried out on twenty IDDM children who compared with other twenty healthy non-diabetic ones with the same age and sex. The data revealed that children with IDDM established high weight-for-age (W/A)Z (P < 0.001) , high weight-for-height (W/H)Z (P < 0.05) and high glycated hemoglobin (HbA1c% ) (P < 0.0001). Both diabetic boys and girls showed higher serum leptin levels (7.48 ± 1.86 ng/ml) than the control group (5.92 ± 1.39 ng/ml). Leptin levels were higher in diabetic girls (8.46 ± 2.29 ng/ml) than diabetic boys (6.68 ± 0.91 ng/ml). Significant high level of serum IL-8 concentration (23 ± 11.92 pg/ml) was detected in IDDM children versus the control group (5.69 ± 1.67 pg/ml). On the other hand, serum nitrite values showed significant reduction in the IDDM children (430.78 ± 155.14 Μmol/l) compared to the control group (610.08 ± 192.82 Μmol/l). Correlation analysis showed positive correlation between leptin with age, (W/H)Z and fasting glucose level, furthermore, a positive correlation was established between IL-8 with (W/H)Z, hinting the adipose tissue as a site of its production and no association between NO and other relevant variables was detected. It could be concluded that leptin, IL-8 and NO may play important roles in the pathophysiology and progression of IDDM. Furthermore, the immune cells found in activated state were confirmed by increased pro-inflammatory biomarkers (IL-8). It could be concluded also that IL-8 and NO with their endothelial implications may act together during the course and progression of diabetes leading to cardiovascular disease in adulthood. Thus, these immune cells may serve as therapeutic targets for the treatment and/or prevention of diabetes with its systemic and microvascular complications