Systemic C-reactive protein and vitamin D are not associated with development of chronic musculoskeletal pain over a 2–7 year follow-up period

Prior studies report association between elevated C-reactive protein (CRP), low vitamin D and development of chronic musculoskeletal pain. However, these small studies did not consider relevant and potentially influential biopsychosocial factors. This longitudinal study using UK Biobank data explored associations between baseline (2006-2010; T1) systemic (blood) levels of CRP and vitamin D, biopsychosocial and lifestyle factors, and later presence of chronic musculoskeletal pain (2012-2013; T2; neck/shoulder, back, hip, knee, and 'any pain' aggregation). All participants were free of pain at T1 (N=7564). At T2, N=1531 (20.2%) reported chronic musculoskeletal pain (mean [SD] age 57.9 [7.2] years, 52.5% female) and N=6033 (79.8%) remained pain-free (mean [SD] age 57.6 [7.3] years, 49.2% female). Median (IQR) T1 CRP levels were higher in those who developed chronic musculoskeletal pain at T2 ('any pain' 1.21 mg/L [1.74]) compared to those who did not (1.03 mg/L [1.53]; z range -4.67 to -2.23, p≤0.026). Higher CRP levels at T1 were associated with chronic musculoskeletal pain at T2 for all pain types (OR range 1.10-1.22, p≤0.04) after controlling for age and sex, but not after further controlling for biopsychosocial and lifestyle factors. No significant associations were found between vitamin D levels at T1 and chronic musculoskeletal pain at T2. Results suggest that systemic CRP is not associated with development of chronic musculoskeletal pain over a 2-7-year follow-up period. Additional work is needed to further characterize possible interactions between systemic CRP, other inflammatory biomarkers, and biopsychosocial factors in development of chronic musculoskeletal pain. PERSPECTIVE: This study explored whether systemic levels of C-reactive protein (CRP) and vitamin D in pain-free individuals predicted later chronic musculoskeletal pain (CMP). After accounting for biopsychosocial and lifestyle factors, CRP was not associated with later CMP. Vitamin D was not associated with later CMP in any of the models.