The Association of Perceived Stress to Physical and Affective Health Outcomes in Sickle Cell Disease

Purpose: Pain is a major complication of sickle cell disease (SCD). Stress is known to trigger acute pain crisis or intensify chronic pain in patients with SCD.^{1, 2} There is insufficient evidence about the effects of stress on fatigue, a ubiquitous symptom of SCD or on affective (anger, anxiety, and depression) symptoms in adults with SCD. Because SCD is marked by repeated ischemic attacks and chronic inflammation, which predisposes patients to the differential expressions of genes implicated in stress responses,³ the SCD population is prime for understanding the relationship of stress with physical and affective health outcomes. Guided by the hypothalamic-pituitary-adrenal (HPA) axis theory, the purpose of this descriptive comparative study was to examine the relationship between perceived stress and physical (fatigue); and affective (anger, anxiety, and depression) symptoms in adult patients with SCD. The HPA axis theory states that the stress could induce stress responses and the release of neurotransmitters and hormones (e.g., cortisol, norepinephrine, and epinephrine) that can adversely affect health outcomes, and has been implicated as part of SCD symptomology.⁴We hypothesize that patients with SCD who report high perceived stress would be more likely to also report increased fatigue, anger, anxiety, and depression symptoms compared to patients with SCD who report low perceived stress. 

Methods: Patients (N=54, mean age 36.3±10.9 years [ranged from 22-74 years], 96% African-American, 57% female) who were recruited between March 2015-December 2015 completed a demographic questionnaire, the Perceived Stress Questionnaire, and the PROMIS measures (anger, anxiety, and depression). Data were analyzed using the statistical software R.

Results: We found the mean scores for the study variables to be: perceived stress (0.37±0.18); fatigue (56.5±9.4); anger (51.1±12.4); anxiety (52.9±9.1); and depression (51.6±10.0). As reported in the Table, our comparative analysis results showed statistically significant differences between Low Perceived Stress (PSI<=0.35, n=27) and High Perceived Stress (PSI>0.35, n=27) groups on fatigue, anger, anxiety, and depression.  

Study Variables	Low Stress (PSI<=0.35, n=27)	High Stress (PSI>0.35, n=27)	p Value
Fatigue (10-90)	52.4 (8.6)	60.5 (8.6)	.001
Anger (10-90)	44.5 (10.5)	57.7 (10.6)	<.001
Anxiety (10-90)	47.9 (7.2)	57.9 (8.2)	<.001
Depression (10-90)	45.7 (8.1)	57.5 (8.2)	<.001

Conclusions: Findings provide preliminary evidence of the relationship between perceived stress; and fatigue, anger, anxiety, and depression in patients with SCD. Findings support the HPA axis theory and indicate that stress is associated with negative health outcomes in patients with SCD. Results from future studies will confirm current findings and provide extra evidence to decipher the influence of perceived stress on physical and affective symptoms in patients with SCD. This evidence would be pertinent for informing future cognitive-behavioral intervention studies to decrease fatigue, anger, anxiety, and depression in patients with SCD who report stress.