Obesity and hypertriglyceridemia are significant risk factors for diabetic neuropathy independent of glycemic control….
Peripheral neuropathy is one of the most common microvascular complication affecting diabetic patients. For these patients, neuropathy is a major cause for disability due to pain, loss of protective sensation leading to foot ulceration and amputation. Few medications provide relief from this pain but tight glycemic control is the most effective in managing or preventing this complication. A better understanding of the risk factors associated with the pathophysiology of this complication may provide more effective prevention and treatment therapies.
The Utah Diabetic Neuropathy Study (UDNS) prospectively followed 218 type 2 diabetic subjects without neuropathy symptoms or with recent onset of symptoms within 5 years. The aim of their study was to evaluate risk factors for neuropathy development. Patients had their hemoglobin A1c and fasting lipid panel, weight, height and calculated BMI were analyzed for neuropathy risk. Each patient was tested using the Utah Early Neuropathy Scale (UENS), nerve conduction studies (NCS), quantitative sensory testing (QST) for vibration and cold detection, quantitative sudomotor axon reflex testing (QSART), and skin biopsy with measurement of intraepidermal nerve fiber density (IENFD) and questionnaires regarding symptoms.
Following the testing, patients with recorded abnormalities of ≥ 3 were classified as having probable neuropathy and those with 1–2 as possible neuropathy. The authors found a significant correlation between the number of abnormalities and development of neuropathy. High triglycerides, obesity and ≥ 3 abnormalities were all found to have a significant increase risk for neuropathy.
Using multivariate analysis, the authors reported obesity and triglycerides were related to the loss of small unmyelinated axons based on IENFD measurements. Elevated hemoglobin A1c was related to large myelinated fiber function loss based off of the NCS measurements. Based on their findings, the authors suggest there is a different pathogenesis for injury to sensory axons compared to myelinated motor fibers indicating that diabetic neuropathy is not solely driven by sustained hyperglycemia.
The authors concluded, "These findings indicate obesity and hypertriglyceridemia significantly increase risk for peripheral neuropathy, independent of glucose control."
A. Gordon Smith, J. Robinson Singleton. "Obesity and hyperlipidemia are risk factors for early diabetic neuropathy". Journal of Diabetes and its Complications, 1 June 2013.http://dx.doi.org/10.1016/j.jdiacomp.2013.04.003