Biochemical and molecular study on interleukin-1β gene expression and relation of single nucleotide polymorphism in promoter region with Type 2 diabetes mellitus.

Interleukin-1β (IL-1β) assumes a centric role in the regulation of immune and inflammatory responses and thus has been recognized in immune mediated diseases like type 2 diabetes mellitus (T2DM). We aimed to investigate expressed level of IL-1β and its relation with IL-1β -511T>C polymorphism in T2DM patients. This study enrolled 80 subjects (50 patients with T2DM and 30 healthy control subjects). Laboratory investigations included fasting (FBG) and 2 h postprandial blood sugar (2 h PBG), HBA1c, lipid profile, and renal function tests. Genotyping of IL-1β -511T>C (rs16944) SNP assay by real-time PCR and relative quantitation of IL-1β gene expression transcript by real-time PCR.

RESULTS: T2DM patients had significantly higher FBG and 2 h PBG, HBA1c, LDLc, TC, TG, systolic, and diastolic BP while lower HDLc compared with control group. IL 1- β -511 T>C, CC genotype and C allele were significantly associated with risk of T2DM with odds ratio (OR) 4.73, 95%CI (1.21-18.39) and OR 2.27, 95%CI (1.72-4.40), respectively. Moreover, diabetic patients had significantly higher IL 1- β gene transcript compared with control group (P < 0.001). CC genotype of IL 1- β -511 T > C had the highest significant level of IL 1- β gene transcript demonstrated compared with C/T and T/T genotypes (P < 0.001) in patients.

CONCLUSION: C allele of IL-1 β -511 T >C could be considered risk factor contributor to T2DM and excess level of IL-1 β transcript may disclose to some degree the inflammatory role of cytokines in T2DM.