Low heart rate variability and cancer-related fatigue in breast cancer survivors.

TitleLow heart rate variability and cancer-related fatigue in breast cancer survivors.
Publication TypeJournal Article
Year of Publication2014
AuthorsCrosswell AD, Lockwood KG, Ganz PA, Bower JE
Date Published2014 Jul
KeywordsAdult, Aged, Breast Neoplasms, Fatigue, Female, Heart Rate, Humans, Inflammation Mediators, Meditation, Middle Aged, Mindfulness, Motor Activity, Survivors

Cancer-related fatigue is a common and often long lasting symptom for many breast cancer survivors. Fatigued survivors show evidence of elevated inflammation, but the physiological mechanisms driving inflammatory activity have not been determined. Alterations in the autonomic nervous system, and particularly parasympathetic nervous system activity, are a plausible, yet understudied contributor to cancer-related fatigue. The goal of this study was to replicate one previous study showing an association between lower parasympathetic activity and higher fatigue in breast cancer survivors (Fagundes et al., 2011), and to examine whether inflammation mediates this association. Study participants were drawn from two samples and included 84 women originally diagnosed with early stage breast cancer prior to age 50. Participants completed questionnaires, provided blood samples for determination of interleukin (IL)-6 and C-reactive protein (CRP), and underwent electrocardiography (ECG) assessment for evaluation of resting heart rate variability (HRV), a measure of parasympathetic activity. Results showed that lower HRV was associated with higher fatigue (p<.05), as predicted. In bivariate analyses, HRV was also correlated with circulating concentrations of IL-6 and CRP. However, path analyses did not support inflammation as a mediator of the association between HRV and fatigue; instead, associations among these variables appeared to be driven by age and BMI. These findings identify HRV as a potential contributor to cancer-related fatigue, but suggest that inflammation does not mediate this association in younger, healthy breast cancer survivors who are several years post-treatment. The autonomic nervous system merits additional attention in research on the etiology of cancer-related fatigue.

Alternate JournalPsychoneuroendocrinology
PubMed ID24845177
PubMed Central IDPMC4344376
Grant ListP30 AG028748 / AG / NIA NIH HHS / United States
R01 CA160427 / CA / NCI NIH HHS / United States
R25 CA087949 / CA / NCI NIH HHS / United States
R25CA087949 / CA / NCI NIH HHS / United States
T32 GM084903 / GM / NIGMS NIH HHS / United States
T32 HL007560 / HL / NHLBI NIH HHS / United States
T32AG033533 / AG / NIA NIH HHS / United States
T32GM084903 / GM / NIGMS NIH HHS / United States