Circadian rhythm characteristics of salivary alpha-amylase - a potential stress marker, in breast cancer in- and out-patients: a follow-up study.

Salivary alpha-amylase has been implemented as renewed non-invasive biomarker of interest to measure the levels of stress in humans. In the current clinical study, two-factor repeated-measures cross-sectional design was implemented to determine the salivary alpha-amylase levels and its rhythm characteristics in newly diagnosed female breast cancer in- and out-patients. Alpha-amylase levels were determined using the Salimetrics® salivary alpha-amylase assay kit. Rhythm characteristics of alpha-amylase were computed using the Cosinor Rhythmometry technique. Results showed that the levels of alpha-amylase significantly increased from/to the increasing number of chemotherapy cycle in patients of both group; however the levels were higher in in-patients. Further, results revealed significant differences in rhythm characteristics of alpha-amylase characterized by higher MESOR, lower amplitude, and advanced acrophase in in-patients as compared to out-patients. Current findings indicate that patients of both the groups were associated with progression under stress levels across the number of chemotherapy cycle; however, the levels of stress were higher in in-patients as compared to out-patients. Higher level of stress in cancer in-patients could be attributed to the possible effect of hospitalization and/or relative social isolation. [ABSTRACT FROM AUTHOR]