Depressive Symptoms, Sleep Profiles and Serum Melatonin Levels in a Sample of Breast Cancer Patients

Abstract

Background

Chronobiological changes have been detected in various physiological functions of patients with breast cancer, suggesting dysregulation in the pineal gland and melatonin secretion. This study aimed to assess and measure serum melatonin levels pre- and postoperatively in patients who had been diagnosed for the first time with breast cancer.

Methods

A sample of first-time breast cancer patients, consisting of 45 women aged 25–65 years, was evaluated and psychometric assessment was completed using the Beck Depression Inventory (BDI), Insomnia Severity Index (White, Weinberg et al) and the Epworth Sleepiness Scale (Cardoso, Spence et al). The Morningness-Eveningness questionnaire (MEQ) was used to assess the chronotype. Serum melatonin levels were measured by radioimmunoassay.

Results

Morning and moderately morning chronotypes were prevalent among the sample (25%, 45.8%, respectively). The finding of a mean BDI score of 13.5±11.2 indicated that depressive symptoms were prevalent among the sample. Despite the finding that a mean of the participants apparently had no symptoms of daytime sleepiness (the mean and standard deviations of the ESS were 7.5±4.4), scores on the ISI (a mean of 16.7±SD 7.3) indicated that insomnia symptoms were prevalent in the sample. Melatonin levels showed an inverse relationship with insomnia severity as measured by the ISI and depression severity, as assessed by the BDI. The postoperative melatonin levels were higher than the preoperative levels. Additionally, the psychometric profile differed among various pathological types of breast cancer according to their hormone receptor profile.

Conclusion

Serum melatonin levels correlated significantly with self-reported sleep quality and psychometric profiles of depression in the present sample of breast cancer patients. The melatonin assay, which is relatively easy to carry out, provided a convenient, objective measure of an important biological correlate of sleep quality and depression. This assay thus represented a confirmatory alternative to the self-report instruments, which may sometimes be unreliable. Future studies should further evaluate the utility of melatonin measures in psychiatric and sleep complaints of breast cancer patients.

Keywords:

• beck depression
• breast cancer
• chronotype
• circadian
• melatonin

Acknowledgments

Authors appreciate the efforts of Dr John Zaki (Lecturer of Engineering-Faculty of Engineering at Mansoura University) for his help in conducting the logistic regression analysis of this study. We also appreciate the time and effort given by the participants of the study and the Nursing staff at Mansoura University Oncology center for their help in withdrawing the blood samples and taking care of the included patients during and after the study.

Funding

Nevin FW Zaki, Yomna M Sabri, Omar Farouk, Amany Abdelfatah and John Zaki funded the chemicals and lab kits needed from their own personal resources.

Disclosure

Mr Seithikurippu R Pandi-Perumal reports non-financial support from Somnogen Canada Inc. and personal fees from Springer, during the conduct of the study, although these financial  statements had no role in relation to the current research. The authors report no other conflicts of interest.