Purpose:
A highly standardized protocol, the Trier Social Stress Test (TSST), can experimentally induce hypothalamus-pituitary-adrenal (HPA) axis physiological stress responses assessed with salivary cortisol. Alterations in HPA axis regulation in response to acute stress may correlate with negative psychosocial states or disease progression in patients with chronic disability, such as retinitis pigmentosa (RP).
Methods:
11 RP subjects & 21 normally-sighted healthy controls completed the TSST, Beck Depression Inventory (BDI), Pittsburgh Sleep Quality Index (PSQI), & Perceived Stress Scale. Area under the curve with respect to increase (AUCI) and ground (AUCG) was calculated using 5 salivary cortisol measures for each subject collected pre- & post-TSST.
Results:
RP subjects had statistically significantly higher BDI depression [5.7(95%CI:1.3,10.1)p=0.01], borderline statistically significantly greater PSQI sleep disturbance[1.6(95%CI:-0.1,3.3)p=0.07] & mean perceived stress[3.1(95%CI:-0.4,6.6)p=0.08] vs. controls. On average, RP subjects had statistically significantly greater cortisol responses vs. controls, using repeated cortisol measures controlled for age & time[5(95%CI:0.1,9.8)p=0.04]. AUCI & AUCG trended toward being statistically significantly larger on average in RP subjects vs. controls, adjusted for age & gender[300(95%CI:-13,613)p=0.06] [395(95%CI:-19,808)p=0.06]. In RP, AUCI & AUCG, were not statistically significantly related to ETDRS visual acuity, Pelli-Robson contrast sensitivity or Goldmann visual field, but AUCG was statistically significantly positively correlated with PSQI [47(95%CI:6,88)p=0.03] & lower in retired RP subjects[255(95%CI:35,474)p=0.03].
Conclusions:
On average, RP subjects had increased negative psychosocial symptoms and heightened HPA axis reactivity to acute stress vs. controls, confirming the hypothesis that net increases or post-stress recovery in HPA axis function may be greater in anxious, depressed patients. Differences between patients and controls are more likely when the system is challenged.
Clinical Trial:
http://www.clinicaltrials.gov NCT00475254
Keywords: quality of life • low vision • retinal degenerations: hereditary