Insulin-like growth factor-1 cytokines cross-talk in type 1 diabetes mellitus: Relationship to microvascular complications and bone mineral density

Objective: This study was designed to investigate the association between inflammatory cytokines (IL-8, IL-6) and IGF-1 levels in relation to metabolic control, microvascular complications and bone mineral density (BMD) in a cohort of Egyptian adolescents with T1DM. Research design and methods: Sixty patients with T1DM (mean age was 14.67±1.53years, mean disease duration was 6.87±1.25years) and 40 controls participated in the study. Thirty-six patients (60%) had poor glycemic control (HbA1C measurements ≥8%) while the rest (n=24%, 40%) had good glycemic control (HbA1C measurements <8%). Serum IL-6, IL-8, and IGF-1 levels were measured. Whole body DXA scan were assessed. Total body and lumbar spine (L2-L4) bone mineral content (BMC, g) and bone area (BA, cm 2) were measured by DXA scan, bone mineral density (BMD, g/cm 2) was calculated by BMC/BA. Results: Patients with T1DM had higher IL-6 and IL-8 levels with lower IGF-1 than healthy controls (P< 0.001). Within the T1DM patients those with poor glycemic control had higher IL-6 and IL-8 as well as lower IGF-1 and total BMD than those with good glycemic control (P< 0.001 for all). IL-6 and IL-8 were negatively correlated with IGF-1 (P= 0.005 and 0.021, respectively). The peripheral neuropathy rate was also greater in T1DM patients with poor glycemic control (P= 0.02). Presence of nephropathy or retinopathy was not different (P= 0.69 and 0.50, respectively). Conclusion: High IL-6, IL-8 with low IGF-1 levels are found in adolescents with T1DM. It seems that poor glycemic control exacerbates inflammatory cytokines, increases peripheral neuropathy, and decreases bone mineral density. © 2012 Elsevier Ltd.