Is vitamin D linked to fatigue in patients with rheumatoid arthritis?

  • Jelsness-Jørgensen LP & al.
  • BMJ Open
  • 6 Feb 2020

  • curated by Sarfaroj Khan
  • UK Clinical Digest
Access to the full content of this site is available only to registered healthcare professionals. Access to the full content of this site is available only to registered healthcare professionals.

Takeaway

  • Vitamin D was not associated with fatigue in patients with established rheumatoid arthritis (RA).
  • However, fatigue correlated with RA disease activity, psychological distress and pain.

Why this matters

  • Association of vitamin D status with depression and anxiety has been investigated in patients with RA, but limited studies showed the potential association between vitamin D and fatigue.

Study design

  • A cross-sectional study of 169 patients with established RA.
  • Fatigue evaluated by the Chalder fatigue questionnaire and serum 25(OH)D level evaluated by liquid chromatography-tandem mass spectrometry.
  • Fatigue was compared across 4 groups based on the levels of serum 25(OH)D at 30, 50 and 75 nmol/L.
  • Funding: None disclosed.

Key results

  • Of 169 patients with RA, 116 (68.6%) had low RA disease activity, showing Disease Activity Score 28-joint count C- reactive protein (DAS28-CRP score,
  • Patient’s mean (standard deviation) serum 25(OH)D level was 56.3 (21.2) nmol/L; of which, 77 (46%) patients had serum 25(OH)D concentration
  • A weak and non-significant association was observed between fatigue and serum 25(OH)D level (r=−0.14; 95% CI, −0.29 to 0.03; P=.08).
  • Multivariate analysis showed fatigue was significantly associated with RA disease activity (DAS28-CRP: β=0.66; 95% CI, 0.14-1.18; P=.01), psychological distress (β=0.32; 95% CI, 0.21-0.44; P<.001 and pain ci p=".01)," but not with serum level to>
  • Fatigue score did not differ across varying levels of serum 25(OH)D (P=.37).

Limitations

  • Single-centre study.