# Association Between Social Jetlag and Low Back Pain in Brazilian Women

## TL;DR

This study found that Brazilian women with high social jetlag and prescription pain medication use are more likely to have chronic low back pain.

## Contribution

The study identifies an interaction between social jetlag and pain medication use in predicting chronic low back pain in women.

## Key findings

- The prevalence of chronic low back pain was 46.8% in the sample population.
- Women with ≥2 hours of social jetlag had an 83% higher probability of CLBP when using pain medications.
- Social jetlag and medication use interact to increase CLBP risk.

## Abstract

Introduction

Chronic low back pain (CLBP) is one of the biggest public health issues globally and can have a major impact on an individual’s quality of life. Social jetlag (SJL) comprises a misalignment in an individual's circadian rhythm due to social imposition. Previous studies have mentioned a possible relationship between sleep-related disorders and the presence of CLBP.

Objectives

The present study aimed to explore the association between SJL and CLBP in women.

Methodology

A cross-sectional population-based study was conducted with a representative sample of 1068 women aged between 20 and 69 years from Southern Brazil. The presence of SJL was evaluated according to the absolute difference between the onset of sleep on free days and the onset of sleep on working days. CLBP was considered present if the pain persisted for ≥ 12 weeks. Poisson regression with robust variance was used to estimate prevalence ratios (PRs) with a 95% confidence interval (CI).

Results

The prevalence of CLBP in the sample population was 46.8% (95% CI: 43.8-49.8). The prevalence of SJL of <1 hour was 68.3% and that of SJL of ≥ 1 hour was 31.5% (16.6% with one to two hours and 14.9% with ≥ 2 hours). After stratification of the sample for use of prescription pain medications, women with SJL of ≥ 2 hours had an 83% higher probability of having CLBP when compared to women with a SJL of < 1 hour (PR = 1.83; 95% CI: 1.40-2.40; p < 0.001). This included adjustment for potential confounding factors.

Conclusions

The findings of this study revealed that women who used prescription pain medications and had SJL of ≥ 2 hours had an 83% higher probability of having CLBP. The use of prescription pain medications has been shown to be an interaction factor in the relationship between SJL and CLBP.