Background: Low back pain (LBP) is associated with obesity and central adiposity. This study evaluated associations of weight-adjusted waist index (WWI) and waist–hip ratio (WHR) with LBP severity and disability.

Methods: A hospital-based cross-sectional study was conducted from March to December 2025. A total of 500 patients aged 18–80 years with LBP were enrolled. Participants were categorized by pain duration: acute (<6 weeks, n=140), sub-acute (6-12 weeks, n=130), and chronic (>12 weeks, n=230). Anthropometric measurements (WWI, WHR, and BMI) were recorded. Pain intensity and functional disability were assessed using the visual analogue scale (VAS) and Nepali version of the Oswestry Disability Index (NV-ODI).

Results: WWI was significantly higher in chronic LBP patients (12.02 ± 1.18) than in acute and sub-acute groups (11.51 ± 1.07 and 11.51 ± 0.93; p<0.001). WHR showed a borderline association (p≈0.051), while BMI was not significantly different across groups (p>0.05). VAS and NV-ODI scores were highest in chronic LBP (55.53 ± 11.47 and 46.82 ± 13.80; p<0.001). Overall, higher WWI was associated with greater pain severity and functional limitation, whereas BMI and WHR showed weaker associations.

Conclusion: WWI was associated with chronic LBP, greater pain, and disability, suggesting its potential value in assessing central adiposity in LBP management.

Keywords: Low back pain, weight-adjusted waist index, waist–hip ratio, body mass index