Lower serum extracellular superoxide dismutase levels are associated with polyneuropathy in recent-onset diabetes

• Published in: Experimental & molecular medicine Vol. 49; no. 11; p. e394
• Main Authors: Strom, Alexander, Kaul, Kirti, Brüggemann, Jutta, Ziegler, Iris, Rokitta, Ilka, Püttgen, Sonja, Szendroedi, Julia, Müssig, Karsten, Roden, Michael, Ziegler, Dan
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 17.11.2017; Springer Nature B.V; Nature Publishing Group
• Subjects: 692/53/2423; 692/699/2743/137/138; 82/80; Adult; Biomarkers; Biomedical and Life Sciences; Biomedicine; Diabetes; Diabetes Complications; Diabetes mellitus; Diabetes Mellitus, Type 1 - complications; Diabetes Mellitus, Type 2 - complications; Diabetic neuropathy; Female; Glutathione; Humans; Male; Medical Biochemistry; Molecular Medicine; Nerve conduction; Original; original-article; Oxidative Stress; Peripheral Nerves - physiopathology; Polyneuropathies - blood; Polyneuropathies - diagnosis; Polyneuropathies - etiology; Polyneuropathy; Sensorimotor system; Sex Factors; Stem Cells; Superoxide dismutase; Superoxide Dismutase - blood; Symptom Assessment; Thiobarbituric acid
• ISSN: 1226-3613; 2092-6413
• DOI: 10.1038/emm.2017.173

Increased oxidative stress is implicated in the pathogenesis of experimental diabetic neuropathy, but translational evidence in recent-onset diabetes is scarce. We aimed to determine whether markers of systemic oxidative stress are associated with diabetic sensorimotor polyneuropathy (DSPN) in recent-onset diabetes. In this cross-sectional study, we measured serum concentrations of extracellular superoxide dismutase (SOD3), thiobarbituric acid reactive substances (TBARS), and reduced glutathione (GSH) in 107 type 1 and 215 type 2 diabetes patients from the German Diabetes Study baseline cohort and 37 glucose-tolerant individuals (controls). DSPN was defined by electrophysiological and clinical criteria (Toronto Consensus, 2011). SOD3 and GSH concentrations were lower in individuals with type 1 and type 2 diabetes compared with concentrations in controls ( P <0.0001). In contrast, the TBARS concentration was higher in participants with type 1 diabetes and type 2 diabetes compared with levels in controls ( P <0.0001). In addition, the SOD3 concentration was higher in participants with type 1 diabetes compared to concentrations in those with type 2 diabetes ( P <0.0001). A low SOD3 concentration was associated with DSPN in individuals with type 1 diabetes (β=−0.306, P =0.002), type 2 diabetes (β=−0.164, P =0.017), and in both groups combined (β=−0.206, P =0.0003). Lower SOD3 concentrations were associated with decreased motor nerve conduction velocity (NCV) in men and, to a lesser degree, with reduced sensory NCV in women with diabetes. In conclusion, several biomarkers of oxidative stress are altered in recent-onset diabetes, with only a lower SOD3 concentration being linked to the presence of DSPN, suggesting a role for reduced extracellular antioxidative defense against superoxide in the early development of DSPN. Diabetes: Reduced antioxidant defences and nerve damage German researchers have identified a blood marker associated with peripheral nerve dysfunction in patients recently diagnosed with diabetes. Previous studies indicated that oxidative stress plays a major role in the development of chronic nerve damage and other complications of diabetes. High sugar levels not only increase the production of free radicals but also impair the body's antioxidant defence system. Alexander Strom and colleagues from the German Diabetes Center at Heinrich Heine University in Düsseldorf, measured the levels of key markers of oxidative stress in over 300 patients with well-managed recent-onset diabetes. They found that lower levels of the antioxidant extracellular superoxide dismutase were associated with the presence of polyneuropathy. These findings suggest that despite good blood glucose control, oxidative stress could lead to nerve damage in the early stages of diabetes.