STUDY DESIGN: A retrospective cohort study from the Kaiser Permanente Spine Registry OBJECTIVE.: Determine whether obese and extremely obese patients with lumbar spine fusions lost a clinically significant amount of weight (> 5%) 1 year after their surgery SUMMARY OF BACKGROUND DATA.: Obesity in the United States has a prevalence of 35% and is a global health issue. Obesity is associated with lumbar spine disease. There is limited evidence regarding post-surgical weight loss after spine surgery.
METHODS: Adult patients in the Kaiser Permanente Spine Registry with lumbar fusions performed between 2009 and 2013 were included in the study sample (n = 7303). The outcome of interest was > 5% weight change 1 year post-operative from baseline. Three BMI groups were analyzed (BMI < 30; 30-39 obese; ≥40 extremely obese). Covariate analysis, multivariable logistic regression, odds ratios (OR) and 95% confidence intervals (CI) are provided.
RESULTS: At the time of spine surgery, 4456 (61%) had a BMI < 30, 2519 (34.5%) had a BMI between 30-39, 232 (3.2%) had a BMI≥40, and 96 (1.3%) were missing their intra-operative BMI. We observed the following weight loss pattern: BMI < 30, 11.1%; BMI 30-39, 16.6%; BMI>40, 21.1%. We observed the following weight gain pattern: BMI < 30, 15.6%; BMI 30-39, 12.7%; BMI>40, 9.5%. After risk-adjustment, obese and extremely obese patients were more likely to lose a clinically significant amount of weight 1 year after surgery (BMI 30-39: OR = 1.42, 95%CI 1.22-1.65; BMI≥40: OR = 1.73, 95%CI 1.21-2.47) compared to non-obese patients.
CONCLUSION: In this large cohort of patients with lumbar spinal fusions we observed more significant weight loss in obese and extremely obese patients compared to non-obese patients. Additional research is needed to determine whether this weight loss is due to improvements in back pain and increased physical activity.
LEVEL OF EVIDENCE: 3.
- Journal Article