Interleukin-6 and hs-CRP as Early Diagnostic Biomarkers for Obesity-Related Peripheral Polyneuropathy in Non-Diabetic Patients.

ABSTRACT

The number of obese individuals is surging in developed and developing countries. Obesity predisposes to many serious illnesses. Peripheral neuropathy (PN) is one of its major complications. Interleukin-6 (IL-6) is a pro-inflammatory cytokine secreted by the adipose tissue and is believed to play a principal role in obesity complications. Meanwhile, hs-CRP is a known inflammatory biomarker. This study was designed to detect the role of serum IL-6 and hs-CRP as inflammatory biomarkers in early diagnosis of peripheral neuropathy (PN) in non-diabetic obese patients. Additionally, we aimed to explore the association between IL-6 with the clinical and electrophysiological tests of PN. This cross-sectional controlled study enrolled 150 obese patients and 50 subjects as a control group. The obese groups were subclassified according to BMI into three groups; all participants were subjected to a complete neurological examination and motor, and sensory peripheral nerve conduction studies. Serum IL-6 and hs-CRP levels were assessed using a commercially available ELISA. Our results revealed that obese patients with PN had statistically significant higher values of IL-6 and hs-CRP compared to obese patients without PN and controls (P < 0.001). Meanwhile, levels of both marker were inversely related to nerve conduction velocities (P < 0.001). Obese patients with PN had higher values of serum IL-6 and hs-CRP than diabetic patients without DPN. Because the diagnostic power of both markers in serum was significant, we conclude that they could be a useful diagnostic biomarker of PN.