Physiopathology and diagnosis of cardiotoxicity in patients submitted to chemotherapy treatment

Metabolic response to exercise in childhood brain tumor survivors: A pilot controlled study

BACKGROUND/OBJECTIVES

Survival rates in children diagnosed with malignant brain tumors exceed 70%. A higher risk of dyslipidemia, central obesity, and insulin resistance has been reported among these children. We investigated substrate utilization during submaximal exercise.

DESIGN/METHODS

Ten brain tumor survivors and 10 healthy children were matched by sex, age, and Tanner stage. Participants completed a submaximal incremental exercise test to determine their fat and carbohydrate oxidation rates.

RESULTS

The relative oxygen volume (VO₂ ) peak was significantly higher in the control group than in the survivors of childhood brain tumors (43.3 ± 11.9 and 32.4 ± 10.2 mL/kg /min, P = .04). At the same relative exercise intensity, there was no difference in the carbohydrate or lipid oxidation rate between the two groups, or in the maximal fat oxidation (MFO) rate, or in the heart rate or percentage of VO₂ peak to reach MFO. Healthy children achieved MFO at significantly higher muscular power than did brain tumor survivors (47.9 ± 20.8 and 21.8 ± 9.6 W, P = .003).

CONCLUSION

Because child brain tumor survivors are less physically fit than healthy children, and substrate utilization during submaximal exercise is not different, physical activity should be promoted for child brain tumor survivors.

The role of melatonin on doxorubicin-induced cardiotoxicity: A systematic review

PURPOSE

Doxorubicin, as an effective chemotherapeutic drug, is commonly used for combating various solid and hematological tumors. However, doxorubicin-induced cardiotoxicity is considered as a serious adverse effect, and it limits the clinical use of this chemotherapeutic drug. The use of melatonin can lead to a decrease in the cardiotoxic effect induced by doxorubicin. The aim of this review was to evaluate the potential role of melatonin in the prevention of doxorubicin-induced cardiotoxicity.

METHODS

This review was conducted by a full systematic search strategy based on PRISMA guidelines for the identification of relevant literature in the electronic databases of PubMed, Web of Science, Embase, and Scopus up to January 2019 using search terms in the titles and abstracts. 286 articles were screened in accordance with our inclusion and exclusion criteria. Finally, 28 articles were selected in this systematic review.

RESULTS

The findings demonstrated that doxorubicin-treated groups had increased mortality, decreased body weight and heart weight, and increased ascites compared to the control groups; the co-administration of melatonin revealed an opposite pattern compared to the doxorubicin-treated groups. Also, this chemotherapeutic agent can lead to biochemical and histopathological changes; as for most of the cases, these alterations were reversed near to normal levels (control groups) by melatonin co-administration. Melatonin exerts these protection effects through mechanisms of anti-oxidant, anti-apoptosis, anti-inflammatory, and mitochondrial function.

CONCLUSION

The results of this systematic review indicated that co-administration of melatonin ameliorates the doxorubicin-induced cardiotoxicity.