C reactive protein and depressive symptoms in hemodialysis patients: A questionable association.
Patients with advanced chronic kidney disease (CKD) on haemodialysis (HD) may have increased C reactive protein (CRP) values and depressive symptoms. There is debate about the strength and nature of previously reported associations. We investigated these issues in a cohort of patients on HD.



We screened for depressive symptoms using two valadiated depression screening tools: the Beck Depression Inventory-II (BDI-II), Patient Health Questionnaire (PHQ-9). Demographic and clinical correlates of depression symptoms were eveluated in adjusted linear and logistic regression models, which included extra renal comorbidity and high CRP (>5 mg/L).



Three hundred and ninety-six HD patients were studied; 63.1% male, mean age 63.1 ± 16.4 years, median CRP 6 (5-15) mg/L. Depression scores were similar in those with normal and high CRP (BDI-II (9(5-17) vs. 11(6-20)) or PHQ (4(2-9) vs. 6(2-10)). In adjusted multivariable regression BDI-II scores were associated with previous history of depression (β 10.8, P < 0.001), serum albumin (β 0.41, P < 0.001), anuria (β 2.4, P < 0.037), diabetes (β 2.7, P = 0.033), and age (β -0.10, P = 0.009). High CRP was not independently associated with BDI-II (β 2.20, P = 0.057), though was with PHQ-9 (β 1.20, P = 0.046). In logistic regression those with high CRP were 1.9 times more likely to score ≥16 on BDI-II screening (P = 0.016), but did not relate significantly to a PHQ-score ≥10.



A relationship was observed between CRP and depression symptoms, though the effect was small, of unlikely clinical significance, and inconsistent between depression measures. Previous reports of this association may reflect overlap between symptoms of depression and advanced CKD.
Health Psychology Section, Psychology Department, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.
Joseph
J
Chilcot
Department of Psychology, Centre for Lifespan and Chronic Illness Research, School of Life and Medical Sciences, University of Hertfordshire, Hatfield, UK.
Karin
K
Friedli
Renal Unit, Lister Hospital, East & North Herts NHS Trust, Stevenage, UK.|Hertfordshire Partnership University NHS Foundation Trust, Welwyn Garden City, UK.|Postgraduate Medical School, University of Hertfordshire, Hatfield, UK.
Ayman
A
Guirguis
Department of Psychology, Centre for Lifespan and Chronic Illness Research, School of Life and Medical Sciences, University of Hertfordshire, Hatfield, UK.
David
D
Wellsted
Renal Unit, Lister Hospital, East & North Herts NHS Trust, Stevenage, UK.|Postgraduate Medical School, University of Hertfordshire, Hatfield, UK.
Ken
K
Farrington
UCL Centre for Nephrology, Royal Free Hospital, London, UK.
Andrew
A
Davenport
D000368:Aged; D002097:C-Reactive Protein / Q000378:metabolism*; D003863:Depression / Q000097:blood*; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications*; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis / Q000009:adverse effects* / Q000379:methods / Q000706:statistics & numerical data
D002097:C-Reactive Protein
BDI-II; C reactive protein; PHQ-9; depression; dialysis; inflammation