A pilot observational study of the association between fatigue after stroke and C-reactive protein

Background:
The aetiology of fatigue after stroke is unknown. We explored the relationship  between  fatigue  and  C-reactive  protein  (CRP)  as  a  marker  of inflammation.
Methods:
This  cross-sectional  study  recruited  inpatients  with  a  stroke  (onset within the previous three months) over a five-week period. Those with dysphasia or confusion severe enough to prevent informed consent and those with current infection were excluded. A semi-structured interview determined a) fulfilment of a  case  definition  for  fatigue  and  b)  severity  of  fatigue  (fatigue  assessment  scale, FAS). Venous blood was taken for CRP. A hospital anxiety and depression score (HADS) was used to screen for emotional distress.
Results:
Of the 28 patients recruited (mean age 72.7 years, proportion men 47%), 15  (53%)  fulfilled  the  case  definition  for  fatigue.  C-reactive  protein  data  were logarithmically  transformed  for  analysis.  C-reactive  protein  levels  did  not  differ significantly between those with and without fatigue, according to the case definition (n=28, p=0.35).
 After exclusion of those with pre-stroke fatigue and those with high scores on the HADS (suggestive of emotional distress), the geometric mean CRP of the fatigued group was 16.04 mg/l (95% CI: 7.12–36.14) compared with 5.16 mg/l (95%  CI:  2.7–9.85)  in  the  non-fatigued  group  (n=21,  p=0.025,  unpaired  t  test), but the relationship between FAS and CRP was not statistically significant (r=0.37, p= 0.098).
Conclusion:
This pilot study is the first to demonstrate an association between fatigue after stroke and higher CRP, after excluding patients with pre-stroke fatigue and  those  with  probable  mood  disorders.  If  this  finding  is  confirmed  in  a  larger number of patients, it might provide a target for treating fatigue after stroke.