Obesity as a Risk Factor for Low Back Pain in a Nigerian Population

Background: Various risk factors have been implicated in the etiology of Low back pain (LBP) and the role of obesity has remained contentious till date. The objective of this study was to determine if a relationship exists between obesity and low back pain, and to identify other risk factors.
Methods: This is a case-referent study of patients that presented to the orthopedic clinic from June 2013 to June 2014. The cases were patients that presented with LBP during the period of this study, while the referents were randomly selected patients - without a diagnosis of LBP - that also attended the clinic at the same time. Body Mass Index was calculated and broadly classified into obese and non-obese. It was also further categorized using the WHO international classification. Independent t-tests and Chi-square tests were used to compare means and categorical variables respectively. A binary logistic regression analysis was carried out to determine independent risk factors.
Results: A total of 332 patients were included in the study: 69.6% (n = 231) had LBP and 30.4% (n =101) did not. The mean BMI was 27.11kg/m² ± 4.1. Age, height and weight were statistically associated with LBP but gender was not. The relationship between obesity and LBP was null (OR 2.175 95% CI 0.914 – 5.177, p 0.079); however, at higher classes of obesity (BMI ≥35), the relationship was significant (p 0.000).
Conclusion: Low back pain is a condition that is commoner in the elderly. Although obesity (BMI >30) was not identified as a risk factor, individuals with BMI≥35 are at increased risk. Age, height and weight were all significantly associated with LBP.