Diurnal trajectories of salivary cortisol and α-amylase and psychological profiles in patients with central serous chorioretinopathy

It has been hypothesized that the occurrence of central serous chorioretinopathy (CSC) might be associated with stress. Therefore, our purpose was to investigate the diurnal trajectories of salivary cortisol and alpha-amylase (alpha-Amy) - markers of hypothalamic-pituitary-adrenal (HPA) axis and sympathetic-adrenal-medullary (SAM) system activity, respectively - and psychological profiles in idiopathic acute CSC. This cross-sectional observational case-control study, which included self-reported psychometric questionnaires, was formally approved by the Ethics Committee. Written informed consent was obtained from all participants. Home diurnal saliva collection was scheduled at several timepoints: at awakening, 30 and 60 min later, and at approximately 13:00 h and 20:00 h. Twenty consecutive male subjects with first-episode CSC attending the outpatient clinic of the Retina Medical Service at the Bietti Foundation were enrolled in the study. Twenty age-matched subjects were recruited as controls. After their initial enrollment, 3 subjects per group were excluded. The production of cortisol and alpha-Amy and the scores on the negative subscale of the Positive/Negative Affect Schedule, the Daily Hassles and Stress Scale and the Beck Depression Inventory were higher in the CSC group than in the control group. To estimate the diurnal trends in the production of salivary cortisol and alpha-Amy, an equation was derived for each group of the study population. The equations describing the interpolated regression lines gave salivary cortisol and salivary alpha-Amy slopes that were determined to be significantly different by Student's t-test (cortisol: t = 3.533, p < .001; alpha-Amy: t = 2.382, p = .018). Furthermore, the area under the curve with respect to the ground (AUC(G)) was calculated to summarize repeated salivary biomarker measurements from 07:00 h to 08:00 h for assessment of the cortisol awakening response (CAR) and the alpha-Amy awakening response (AR). The diurnal cortisol AUC(G) and diurnal alpha-Amy AUC(G) were calculated from 07:00 h to 20:00 h. The CAR AUC(G) values of the CSC patients were significantly higher than those of the controls. No differences between the two groups were detected for the alpha-Amy AR AUC(G). The present study adds novel information to the growing body of data suggesting that abnormal diurnal activity of the HPA axis and the SAM system is associated with CSC in susceptible individuals, providing ophthalmologists with a new chronobiological approach for these patients.