Association of Serum Minerals, Vitamin D, Total Protein, and Inflammatory Mediators and Severity of Low Back Pain

Background: Low back pain (LBP) is a multifactorial disorder with multiple etiologies, which are not fully understood. In this study, we aimed to evaluate the relationship between serum levels of minerals, total protein, vitamin D (vit D), and inflammatory mediators with LBP and its severity.

Materials and methods: This case-control study was derived from the study nested in the Fasa Cohort Study. Overall, 148 individuals with LBP were compared with 150 individuals without LBP. Blood samples were evaluated for serum protein, iron (Fe), aluminum (Al), copper (Cu), phosphorus, vit D, IL-1B, IL-6, high-sensitive C-reactive protein (HS-CRP), and TNF-alpha. Severity of pain was measured with the McGill and Oswestry questionnaires.

Results: The mean age of participants in the case and control groups was 49.2 ± 6.1 and 47.57 ± 5.85 years, respectively. In the case group, 61 patients (48.8%) were male. The mean serum levels of Fe, Al, vit D, Cu, IL-1B, IL-6, HS-CRP, and TNF-alpha were significantly different between case and control groups (P≤0.05). However, there were no significant differences between studied groups in the term of sex and serum phosphorus (P>0.05). Regarding pain severity, age was correlated with McGill score (r=0.18), body mass index with Oswestry (r=0.21), Fe with McGill (r=-0.15) and Oswestry (r=-0.13), protein with McGill (r=0.32) and Oswestry (r=-0.32), Al with McGill (r=0.56) and Oswestry (r=0.45), IL-1B with McGill (r=0.19) and Oswestry (r=0.13), TNF-alpha with McGill (r=0.34) and Oswestry (r=0.26), IL-6 with Oswestry (r=0.13), HS-CRP with McGill (r=0.60) and Oswestry (r=0.46), and vit D was correlated with McGill (r=0.21) and Oswestry scores (r=0.17). Higher Fe (odds ratio [OR]: 0.99), protein (OR: 0.47), Al (OR: 0.11), and vit D levels (OR: 0.97) were protective against LBP (P<0.001). Higher IL-1B (OR: 1.01), TNF-alpha (OR: 1.03), and HS-CRP (OR: 1.0003) presented as risk factors for LBP (P<0.001). Conclusion: Our study revealed except phosphorous, all the serum levels minerals and inflammatory markers was significantly different in LBP patients compared to healthy individuals. Also, in the LBP patients, serum levels of Fe, total protein, Al, and vit D aside to inflammatory mediators (i.e., IL-1B, TNF-alpha, and HS-CRP) shows a marked association with severity of LBP.