Diabetes and Glycosylation in Cervical Spondylosis

Overview

The purpose of this study is to determine the relevant significance of diabetes on cervical disc degeneration, and correlate diabetic control (HgbA1C) with disc glycosylation profile in patients undergoing anterior cervical discectomy and fusion for cervical spondylosis. Additionally, to compare the level of degenerative cervical disc glycosylation in patients with and without diabetes. Hypothesis: Patients with diabetes and degenerative cervical disc disease have higher levels of disc tissue glycosylation, and higher levels of glycosylation are correlated with poor outcomes.

Spine surgery has increased substantially in the U.S. during the past decade, with an estimated 100,000 patients undergoing cervical procedures annually. As the demographics of an aging population begin to increase their utilization of healthcare resources, surgeons will undoubtedly be faced with an increasing number of high-risk patients. A number of factors including smoking, obesity, and diabetes significantly contribute to surgical complications following spinal arthrodesis. Nicotine has a direct inhibitory effect on autologous cancellous bone graft revascularization, significantly increasing the rate of bony non-union. Similarly, obesity has been demonstrated to represent a significant risk factor for subsequent pseudoarthrosis and has been linked to nearly a 100% higher in-hospital complication rate. Spine instrumentation in the setting of diabetes has been linked to reduced incidence of bony fusion, increased surgical site infection9, and higher hospital costs. Achieving solid bony fusion following cervical arthrodesis has long been considered the most important primary outcome measure and is highly correlated with patient reported outcome measures. Non-union or pseudoarthrosis following cervical instrumentation can lead to persistent neck pain and/or recurrence of myeloradiculopathy. The incidence of bony fusion is affected by both patient systemic factors and local biologic environment. Significant resources have been invested into studying local environment following spinal arthrodesis, with a particular focus on high-risk patients. Animal studies have suggested diabetes is a significant risk factor for disc degeneration, yet corresponding human studies are lacking. Understanding the mechanism by which diabetes contributes to disc degeneration is the first requisite step in designing therapies to prevent diabetes associated disc degeneration.