title: Does clinical improvement of symptomatic degenerative lumbar disease impact obesity?
abstract: OBJECTIVE Obesity and low-back pain associated with degenerative spondylosis or spondylolisthesis are common comorbid conditions. Many patients report that the pain and disability associated with degenerative lumbar disease are key factors in their inability to lose weight. The aim of this retrospective study was to determine if there is an association between improved functional status and weight loss following a successful transforaminal lumbar interbody fusion (TLIF) procedure. METHODS A retrospective cohort study of patients who underwent single-level TLIF was performed. Inclusion criteria were preoperative body mass index (BMI) greater than 30 kg/m2, achievement of minimum clinically important difference in the Oswestry Disability Index (ODI, defined as improvement of 15 points), and minimum 1-year postoperative followup BMI. Preoperative and postoperative BMI, ODI, and visual analog scale (VAS) scores were compared. A subgroup analysis of patients who achieved substantial clinical benefit (SCB, defined as a net improvement of 18.8 points on the ODI) was also performed. RESULTS A total of 56 patients met the inclusion criteria. The mean age of the study population was 55.6 ± 13.7 years. The mean preoperative BMI was 34.8 ± 4.6 kg/m2, the mean preoperative ODI was 66.2 ± 10.1, and the mean preoperative VAS score was 7.1 ± 1.7. The mean change in ODI was -33.1 ± 13.5 (p < 0.01) and the mean change in the VAS score was -4.1 ± 2.1 (p < 0.01). The mean change in BMI was +0.15 ± 2.1 kg/m2(range -4.2 to +6.5 kg/m2; p = 0.6). SCB was achieved in 46 patients on the ODI. The mean preoperative BMI for patients with SCB was 34.8 ± 4.8 kg/m2, and the mean postoperative BMI was 34.7 ± 5.0 kg/m2. The mean change in BMI was -0.03 ± 1.9 kg/m2(p = 0.9). CONCLUSIONS Despite successful surgical intervention via TLIF with achievement of improved function and pain, obese patients did not have significant change in weight postoperatively.
authors.affiliation: Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan.
authors.forename: Jacob R
authors.initials: JR
authors.lastname: Joseph
authors.affiliation: Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan.
authors.forename: Zishaan
authors.initials: Z
authors.lastname: Farooqui
authors.affiliation: Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan.
authors.forename: Brandon W
authors.initials: BW
authors.lastname: Smith
authors.affiliation: Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan.
authors.forename: Elyne N
authors.initials: EN
authors.lastname: Kahn
authors.affiliation: Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan.
authors.forename: Xilin
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan.
authors.forename: Frank
authors.initials: F
authors.lastname: La Marca
authors.affiliation: Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan.
authors.forename: Paul
authors.initials: P
authors.lastname: Park
mesh_terms: D015992:Body Mass Index; D004185:Disability Evaluation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000150:complications* / Q000601:surgery*; D017116:Low Back Pain / Q000150:complications* / Q000601:surgery*; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications* / Q000601:surgery; D010147:Pain Measurement; D012189:Retrospective Studies; D013123:Spinal Fusion; D016896:Treatment Outcome; D015431:Weight Loss
keywords: BMI = body mass index; MCID = minimum clinically important difference; ODI = Oswestry Disability Index; SCB = substantial clinical benefit; TLIF = transforaminal lumbar interbody fusion; VAS = visual analog scale; body mass index; degenerative lumbar disease; minimum clinically important difference; obesity; substantial clinical benefit; transforaminal lumbar interbody fusion; weight loss