Background and aims: To investigate the association of plasma osteoprotegerin (OPG) levels with diabetic neuropathy.
Methods: Forty-two diabetic patients (21 female and 21 male) and twenty-four non-diabetic healthy control subjects (12 female and 12 male) were included in the study. All consecutive diabetic patients who came for routine follow-up at our outpatient clinic were invited to participate in this clinical study. We studied EMG and neuropathy symptom score in all study subjects. Fasting plasma glucose, HbA1 C, hs-CRP, OPG levels and lipid profile were measured for each subject.
Results: Serum fasting glucose, HbA1c, HOMA-IR, total cholesterol, triglyserid, LDL-Cholesterol, HDL-Cholesterol, lipoprotein (a), apolipoprotein-b, hs-CRP, OPG levels, and neuropathy symptom score were statistically higher in diabetic patients than in healthy control subjects. Plasma OPG levels was statistically higher in diabetic patients than it was in nondiabetic control subjects. However, plasma OPG levels were not significantly different between diabetic patients without neuropathy and healthy control subjects. On the other hand, OPG levels were statistically higher in diabetic patients with neuropathy than in patients without neuropathy. In addition to that serum fasting glucose, HbA1c, hs-CRP, diabetes duration, neuropathy symptom score were statistically higher in diabetic patients with neuropathy than they were in patients without neuropathy. In total group of subjects, plasma OPG levels were correlated significantly with age, diabetes duration, HbA1c, total cholesterol, HDL-cholesterol, lipoprotein (a), apolipoprotein b, hs-CRP. In diabetic patients, plasma OPG correlated significantly with age, diabetes duration, neuropathy symptom score, HbA1c, lipoprotein (a), apolipoprotein b levels.
Conclusions: The major findings of this study were that the plasma OPG concentrations were higher in type 2 diabetic patients than OPG concentrations in healthy control subjects and they were positively correlated with diabetic neuropathy. This finding supports the growing concept that OPG acts as an important regulator in the development of vascular dysfunction in diabetes.