Causations between obesity, diabetes, lifestyle factors and the risk of low back pain

Despite numerous observational studies, the causal relationship between obesity-measured by body mass index (BMI) and waist circumference (WC)-as well as type 2 diabetes (T2D), lifestyle habits, and susceptibility to low back pain (LBP) remains obscure.

This investigation employed two-sample Mendelian randomization (MR) analysis to explore causality, using genetic variants linked to relevant factors from genome-wide association studies (GWASs). Specifically, we selected independent genetic variants related to BMI, WC, T2D, smoking, alcohol consumption, and coffee intake from established GWASs, all of which demonstrated genome-wide significance. The comparative data for LBP were derived from a GWAS involving European subjects, under the auspices of the renowned MRC-IEU (Medical Research Council Integrative Epidemiology Unit) consortium.

Elevated BMI and WC were associated with odds ratios of 1.002 (95% confidence interval [CI] = 1.001-1.004, p < 0.001) and 1.003 (95% CI = 1.002-1.004, p < 0.001) for LBP per standard deviation (SD) increase, respectively. Regarding smoking initiation and coffee consumption, the odds ratios stood at 1.002 (95% CI = 1.001-1.004, p = 0.001) and 1.004 (95% CI = 1.001-1.008, p = 0.034) for LBP, respectively. However, an augmented log odds ratio for T2D and each SD rise in alcohol consumption frequency revealed no significant causal impact on LBP risk.

Our findings indicate a potential causal link between obesity, smoking, and coffee intake in the genesis of LBP, suggesting that mitigating these factors could contribute to LBP prevention.