Influence of Body Mass Index on Subjective and Objective Measures of Pain, Functional Impairment, and Health-Related Quality of Life in Lumbar Degenerative Disc Disease.
Stienen MNDepartment of Neurosurgery, Faculty of Medicine, University Hospital Geneva, Geneva, Switzerland. Electronic address: mnstienen@gmail.com.
Joswig HDepartment of Neurosurgery, Cantonal Hospital St. Gallen, St. Gallen, Switzerland.
Smoll NRSchool of Medicine and Public Health, University of Newcastle, Newcastle, Australia.
Corniola MVDepartment of Neurosurgery, Faculty of Medicine, University Hospital Geneva, Geneva, Switzerland.
Schaller KDepartment of Neurosurgery, Faculty of Medicine, University Hospital Geneva, Geneva, Switzerland.
Hildebrandt GDepartment of Neurosurgery, Cantonal Hospital St. Gallen, St. Gallen, Switzerland.
Gautschi OPDepartment of Neurosurgery, Faculty of Medicine, University Hospital Geneva, Geneva, Switzerland.
English
OBJECTIVE To analyze the influence of body mass index (BMI) on subjective and objective measures of pain, functional impairment, and health-related quality of life in patients with lumbar degenerative disc disease undergoing surgery.
METHODS Prospective institutional review board-approved 2-center study, measuring visual analog scale (VAS) back and leg pain, Roland-Morris Disability Index (RMDI), Oswestry Disability Index (ODI), EuroQol 5D questionnaire, and Short Form-12 at baseline, 6 weeks, 6 months, and 1 year postoperatively. T-scores of objective functional impairment (OFI) were determined using the Timed Up and Go (TUG) test.
RESULTS A total of 375 patients with a median BMI of 26.6 kg/m2 (94 obese patients [BMI ≥30 kg/m2]) were included. Obese patients presented more VAS back pain (mean, 4.7 vs. 3.6; P = 0.001) and greater disability on the RMDI (mean, 12.6 vs. 11.3; P = 0.045). The prevalence and severity of OFI were similar in obese and nonobese patients. There was a weak positive correlation between BMI and VAS back pain (r = 0.1552; P = 0.0026), on both RMDI (r = 0.1138; P = 0.0276) and ODI (r = 0.1075; P = 0.0374). There was no correlation between BMI and TUG T-scores (r = 0.0475; P = 0.3585). Obese patients were as likely as nonobese patients to show a positive 6-week treatment response, and the outcome up to 1 year was similar.
CONCLUSIONS BMI positively correlates with VAS back pain, RMDI, and ODI. Standardized TUG T scores reflect the patient's degree of OFI well, irrespective of BMI. The TUG test appears to be a good means to estimate functional impairment in populations with a high prevalence of obesity.