Endocrine Abstracts

Introduction: Apart from genetics, autoimmunity has been implicated in pathogenesis of diabetes mellitus (DM). Further the role of vitamin B12 levels in diabetic immunomodulation is controversial. In this context, we set out study the role of Pro– inflammatory cytokines in DM with or without vitamin B 12 deficiency in South Indian population.

Material and Methods: This prospective case–control study was conducted on diabetes mellitus patients. Institutional ethical committee approval was obtained. Exclusion criteria were subjects with any systemic or chronic inflammatory disease or taking B12 supplements, proton pump inhibitors or any medication which interferes with the normal function of the hypothalamic–pituitary–gonadal axis. Serum samples were collected from 100 diabetic subjects and 20 age matched healthy controls. Cases were divided in to two groups A and B with deficient and sufficient serum vitamin B12 levels respectively. Controls are considered as group C. Interleukin–6 (IL–6), Tumour necrosis factor–alpha (TNF– α) and high sensitive C reactive protein (hsCRP), leptin levels were measured in all serum samples. Statistical analysis was performed by one way ANOVA with Dunnet’s test and Pearson correlation tests.

Results: The mean hSCRP level in groups A, B and C were 17.1 ± 3.1 mg/ml, 6.3 ± 0.9 mg/ml and 5.6 ± 1.2 mg/ml respectively. The mean TNF– α, IL–6, Leptin levels in groups A and B were 278 ± 32 pg/ml, 12.8 ± 4.3 pg/ml, 2.85 ± 0.8 ng/ml and 168 ± 21 pg/ml, 4.8 ± 1.3 pg/ml, 11.85 ± 2.7 ng/ml respectively. The corresponding values in group C were 147 ± 16 pg/ml, 3.8 ± 1.1 pg/ml, 10.66 ± 1.7 ng/ml. There was statistically significant difference of all the pro–inflammatory cytokines compared between group A with B and C (P value < 0.05) with negative correlation for leptin levels. Similar comparision between group B and control group C was not statistically significant (P value > 0.05)

Conclusions: Our study showed diabetic patients with raised titers of pro–inflammatory markers – IL–6, TNF–α and hsCRP, while reduced leptin levels correlated significantly with vitamin B 12 status, suggesting its significant contributory role. But, the exact immuno–modulatory role and pathogenetic mechanism of vitamin B12 metabolism needs more research.

Keywords: diabetes, tumour necrosis factor, interleukin–6, goiter, auto–immunity, leptin.