Serum Copeptin, Perceived Stress, and Pain in Patients Living with Sickle Cell Disease

Sickle cell disease (SCD) is a hereditary blood disorder characterized by intense acute and chronic pain episodes, resulting in a complex interplay of negative physical and emotional experiences. One of the main barriers to addressing pain in this disease state is the limited information about the mechanisms affecting the variable degree and types of pain and stress that impact patients in this population. The arginine vasopressin receptor1a gene (AVPR1A) single nucleotide polymorphism (rs10877969) is associated with aspects of acute pain and stress related pain in patients living with SCD. Arginine vasopressin (AVP) is a hormone known for its role in regulating extracellular fluid, vasoconstriction, and the endocrine stress response. However, due to its short half-life, AVP is difficult to measure. Thus, copeptin, the stable biologically inactive C-terminal portion of pro-vasopressin, is often used as a surrogate marker for AVP secretion. Copeptin is a marker of hypothalamic-pituitary-adrenal axis activation, however, its levels have not been studied in patients living with SCD. Psychological stress has been associated with changes in circulating copeptin concentrations. Considering the relationship between pain, stress, and copeptin, it is important to investigate their relationship in the context of SCD. The primary objective of this study was to examine serum copeptin levels with reports of perceived stress and pain in this patient population.

In this cross-sectional study, we investigated serum copeptin levels, perceived stress, and pain experiences in a cohort of 50 adults living with SCD. Th participants had a mean age of 39.8±8.5 years, ranging from 29 to 59 years. Ninety-six percent of the participants were of African ancestry and 62% were female. Participants had the following hemoglobin genotypes: 68% had SS, 24% had SC, and 8% had other Hgb genotypes. To assess pain experiences, participants responded to questionnaires, including the Average Pain Intensity (API, average of current, least, and worst pain experienced within a 24-hour period, measured on a scale from 0 to 10). The Adult Sickle Cell Quality of Life Measure (ASCQ-Me) was used to measure number of vaso-occlusive crises (VOC). Perceived stress was assessed using the Perceived Stress Scale (PSS). Serum copeptin levels were quantified using a well-established laboratory. All the participants provided blood samples and completed psychological scales. Descriptive statistics and bivariate associations were conducted using R statistical software package. The study received approval from the Institutional Review Board at the University of Tennessee Health Science Center.

We observed no significant differences in mean copeptin levels by sex ( p=.33) or associations between copeptin levels and age ( p=.66), weight ( p=.81), number of hospitalizations due to pain crisis ( p=.23), and the number of pain crisis managed at home ( p=0.07). The coefficients for API .92 ( p=.05) and PSS .97 ( p=.03) exhibited statistically significant positive association with copeptin levels.

Our findings provide insights into the relationship between serum copeptin levels, perceived stress, and pain intensity in patients with sickle cell disease (SCD). The positive associations observed between copeptin levels and both perceived stress and average pain intensity underscore the potential interchange of pain and psychological stress in the regulation of copeptin secretion in this patient population. Our results indicate that copeptin levels are not significantly influenced by sex, age, or weight suggesting that these demographic factors may not be major determinants of copeptin viability in patients living with SCD. While sickle cell severity indicators did not show significant associations with copeptin levels, further investigation with larger sample sizes is needed to validate these findings and explore additional factors contributing to pain and psychological stress in individuals living with SCD. Ultimately, understanding the complexities of copeptin regulation may lead to improved pain management strategies and enhanced overall well-being for patients with this challenging disorder.