The impact of diabetes on the outcomes of surgical and nonsurgical treatment of patients in the spine patient outcomes research trial.

STUDY DESIGN: A secondary analysis comparing diabetic patients with nondiabetic patients enrolled in the Spine Patient Outcomes Research Trial (SPORT).

OBJECTIVE: To compare surgical outcomes and complications between diabetic and nondiabetic spine patients.

SUMMARY OF BACKGROUND DATA: Patients with diabetes are predisposed to comorbidities that may confound the diagnosis and treatment of patients with spinal disorders.

METHODS: Baseline characteristics and outcomes of 199 patients with diabetes were compared with those of the nondiabetic population in a total of 2405 patients enrolled in the Spine Patient Outcomes Research Trial for the diagnoses of intervertebral disc herniation (IDH), spinal stenosis (SpS), and degenerative spondylolisthesis (DS). Primary outcome measures include the 36-Item Short Form Health Survey (SF-36) Health Status questionnaire and the Oswestry Disability Index.

RESULTS: Patients with diabetes were significantly older and had a higher body mass index than nondiabetic patients. Comorbidities, including hypertension, stroke, cardiovascular disease, and joint disease, were significantly more frequent in diabetic patients than in nondiabetic patients. Patients with diabetes and IDH did not make significant gains in pain and function with surgical intervention relative to diabetic patients who underwent nonoperative treatment. Diabetic patients with SpS and DS experienced significantly greater improvements in pain and function with surgical intervention when compared with nonoperative treatment. Among those who had surgery, nondiabetic patients with SpS achieved marginally significantly greater gains in function than their diabetic counterparts (SF-36 physical function, P = 0.062). Among patients who had surgery for DS, diabetic patients did not have as much improvement in pain or function as did the nondiabetic population (SF-36 bodily pain, P = 0.003; physical function, P = 0.002). Postoperative complications were more prevalent in patients with diabetes than in nondiabetic patients with SpS (P = 0.002). There was an increase in postoperative (P = 0.028) and intraoperative (P = 0.029) blood replacement in DS patients with diabetes.

CONCLUSION: Diabetic patients with SpS and DS benefited from surgery, though older SpS patients with diabetes have more postoperative complications. IDH patients with diabetes did not benefit from surgical intervention.