Body Mass Index and its Association with Lumbar Disc Herniation and Sciatica: a Large‐Scale, Population‐Based Study

Abstract

INTRODUCTION: Elevated body mass index (BMI) or overweight and obesity are pan‐ demics. Lumbar disc herniation and sciatica occur in every population and present se‐ vere socioeconomic consequences. How‐ ever, little is known regarding the role of BMI with lumbar disc herniation and sciat‐ ica. As such, the following large‐scale study addressed the association of BMI, in partic‐ ular overweight and obesity, with disc her‐ niation, its global lumbar involvement and its implications with the development of sciatica. METHODS: A cross‐sectional study of 2,596 Southern Chinese (mean age: 42 years; 60% females) was conducted assessing T2‐weighted MRI, environmental and lifestyle factors, as well as clinical profiles of sciatica. On imaging, the presence of disc bulge/extrusion (DBE) and other spinal phe‐ notypes from L1‐S1 were assessed. A total DBE (TDBE) Score of L1‐S1 was calculated. Asian‐modified BMI values and categories were obtained of each subject. Results: DBE was noted in 46.3% of the sub‐ jects, mainly occurring at L4‐S1. The mean TDBE score was 0.7. Historical prevalence of sciatica was 44.6%, with 17.9% reporting sciatica at the time of assessment. The mean BMI was 22.9 kg/m2 (7.2% under‐ weight, 47.9% normal‐weight, 36.1% over‐ weight, 8.9% obese). TDBE Score sig‐ nificantly increased with elevated BMI cate‐ gories (p<0.001). Multivariate analyses not‐ ed that elevated BMI was significantly asso‐ ciated with DBE [normal‐weight (Ref); un‐ derweight OR: 0.71(0.49‐1.03); overweight OR: 1.26(1.04‐1.52); obese OR: 1.78(1.30‐ 2.44)]. TDBE score (OR: 1.36; 1.15‐1.60) and obesity (OR: 1.68;1.25‐2.24) were signifi‐ cantly related with sciatica. Worse function‐ al and disability scores were associated with sciatica (p<0.05). DISCUSSION: Based on the largest popula‐ tion‐based study to assess the role of BMI and its association with disc herniation, overweight and obesity significantly in‐ creased the likelihood of having lumbar DBE, its global severity and the risk of de‐ veloping sciatica.