Background: Idiopathic neuropathy patients are at high risk of impaired glucose tolerance (IGT). Hyperglycemia, low high density lipoprotein (HDL), elevated triglycerides (TRG), hypertension and central obesity co-associate and constitute the metabolic syndrome. Patients with hyperglycemia are at high risk of having the syndrome and each of its features. Our null hypothesis was that patients with neuropathy and IGT would have a higher prevalence of other metabolic syndrome features than those without hyperglycemia. The primary objective was to determine if metabolic syndrome features other than hyperglycemia increase neuropathy risk.
Methods: The prevalence of metabolic syndrome features was determined among 219 sequential patients with idiopathic peripheral neuropathy. Subjects were classified as having IGT or normoglycemia. The prevalence of metabolic syndrome was compared to published population prevalence data. To compensate for potential referral bias, data were also compared for175 diabetic subjects without neuropathy, given the well-recognized risk of metabolic syndrome among diabetic individuals.
Results: Contrary to our hypothesis, neuropathy patients with normoglycemia and IGT shared a similarly elevated prevalence of metabolic syndrome features compared to published normal populations. Compared to diabetic subjects without neuropathy, the normoglycemic neuropathy patients had significantly higher total and LDL cholesterol, and a higher prevalence of abnormal HDL and triglycerides. The prevalence of obesity and hypertension was similar among patient groups. Normoglycemic neuropathy subjects had significantly more features of metabolic syndrome (other than hyperglycemia) than diabetics.
Conclusions: These findings demonstrate an association between neuropathy and metabolic syndrome features other than hyperglycemia. Lipid abnormalities are particularly prevalent among neuropathy subjects.