Team triathlon effects on physiological, psychological, and immunological measures in women breast cancer survivors

Biological mechanisms of cancer-related fatigue in breast cancer survivors after treatment: a scoping review

PURPOSE

Cancer-related fatigue (CRF) is the most common symptom experienced by cancer survivors. It is a multidimensional symptom affecting physical, emotional, and/or cognitive spheres, different from other types of fatigue. Characteristically is not alleviated by sleep or rest. CRF could have specific features in breast cancer survivors (BCS), because of sex, hormones, and distinct treatments. On the other hand, more than 25% of BCS report persistent CRF for 10 years or more after the diagnosis. The present study aims to recapitulate the knowledge about the biological mechanisms that potentially drive CRF in BCS after treatment.

METHODS

To answer a broad question, a scoping review methodology was used. Data were collated from three bibliographic databases: PubMed, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL). Studies were selected if they had included more than 20 BCS, after finishing their treatment, fatigue was measured with a quantitative scale and biomarkers were analyzed.

RESULTS

The final database was composed of 1896 records. Sixty-four studies finally met the eligibility criteria. Inflammation (61%), hypothalamic-pituitary-adrenal (HPA) axis dysregulation (14%), autonomic nervous system (ANS) dysfunction (11%), and diet (9%) were the biological pathways most frequently studied. Unfortunately, results from studies about inflammation and HPA axis show many inconsistencies.

CONCLUSION

More research about the role of ANS dysfunction and diet on the pathogenesis of CRF would be warranted according to the results of the review. There are some fields such as endocannabinoid systems, mitochondrial dysfunction, gut microbiota, and oxidative stress that have been insufficiently explored.

IMPLICATIONS FOR CANCER SURVIVORS

To widen the scope of future research in the physiopathology of CRF, it is necessary to identify mechanisms that would be potentially involved and have been insufficiently explored. Because of the high prevalence of CRF in BCS and the tremendous impact that fatigue has in their quality of life, it is essential to improve the efficacy of the treatments through a good knowledge of the biological basis of CRF.

Impacts of different triathlon races on systemic cytokine profile and metabolic parameters in healthy individuals: a systematic review

The present systematic review aimed to discuss the impacts of different triathlon protocols on the level of pro and anti-inflammatory cytokines, as well as biomarkers related to the performance of healthy individuals. Four databases [PubMed (28 articles), Scopus (24 articles), Science Direct (200 articles), and SPORT Discus (1101 articles) were assessed. The eligibility criteria were applied, and the selected articles were used in the peer review, independently, as they were identified by March 2022. Of the 1359 articles found, 10 were included in this systematic review. Despite the difference in triathlon protocols, it was observed an increase in pro and anti-inflammatory cytokines including IL-4 and IL-10, and chemokines, such as IL-8 and MCP-1. Moreover, the anti-inflammatory serum levels increase after triathlon. Overall, the studies also reported enhancement in the serum levels of cortisol, creatine kinase, C reactive protein, Endothelial Growth Factor, Vascular Endothelial Growth Factor, Myostatin, Lactate dehydrogenase, free fatty acids, and lactate dehydrogenase in triathlon athletes. This systematic review indicates that different triathlon race promotes an acute elevation of circulating cytokines and chemokines levels which return to standard levels after triathlon races. The findings of this systematic review demonstrate that the modulation of inflammatory parameters may be associated with an increase in metabolic indicators (CK, Cortisol, and LDH) after the end of different types of triathlon races.

Physical Activity and Breast Cancer Survival-Epidemiologic Evidence and Potential Biologic Mechanisms

PURPOSE OF REVIEW

To review the biologic mechanisms that may be operative between physical activity and survival after breast cancer.

RECENT FINDINGS

Physical activity decreases risk of mortality from breast cancer by up to 40%. Several biologic mechanisms have been hypothesized to explain this association. Previous cohort studies and randomized trials have examined the primary mechanisms that appear to be operative, which involve a decrease in sex hormone levels, insulin resistance, and inflammation. The evidence is still inconsistent and several limitations in the existing literature exist. Understanding the biologic mechanisms involved in the association of physical activity and breast cancer survival will provide more precision to physical activity guidelines for cancer survival. To achieve this objective, future research should include direct measurements of physical activity, sedentary behaviour, and health-related fitness to provide a more comprehensive assessment of these factors and their association with biomarkers and survival after breast cancer.

Interaction of chronic pain, obesity and time of day on cortisol in female human adolescents

Adolescent obesity augments and impedes the treatment of chronic pain. This is associated with increased systemic inflammation and is more prominent in females. In addition, pain and obesity each independently affect the hypothalamic-pituitary-adrenal (HPA) axis. However, the interaction of pain and obesity on the HPA axis and the potential for sexual dimorphism in this phenomenon is not established. We hypothesized that dysregulation of the HPA axis occurs in female human adolescents with chronic pain, obesity, or the combination of the two and is associated with gonadal steroids. We measured serum cortisol, estradiol, and testosterone in 13-17-year-old adolescent females (N = 79) from venous blood drawn during the daytime (0830-1730 h) and analyzed the data in toto and partitioned by morning vs. afternoon sampling time. Subjects were categorized as healthy weight/no pain (controls; BMI = 56^th percentile [37-71]), healthy weight with chronic pain, obese without pain (BMI = 97^th percentile [95-99]), or the combination of obesity and chronic pain. Serum cortisol was lower with chronic pain and/or obesity compared to healthy controls and was lower with chronic pain and obesity compared to chronic pain alone (healthy weight). The lower serum cortisol in the pain alone group was more prominent in the morning compared to the afternoon. There was no relationship between serum estradiol and testosterone and study group. The decrease in the anti-inflammatory and other pain-ameliorating effects of cortisol may contribute to chronic pain and its resistance to treatment with concurrent obesity in female adolescents.