Exercise as it relates to Disease/Does aerobic and resistance exercise reduce the risk of cardiovascular disease in women with early-stage breast cancer?

This is a critique of the research article:Kyuwan L (2019) Effect of Aerobic and Resistance Exercise Intervention on Cardiovascular Disease Risk in Women With Early-Stage Breast Cancer

This critique was undertaken as an assignment for the unit Health, Disease, and Exercise (8340) at the University of Canberra, during Semester 2 of 2020.

What is the background to this research?

The risk of cardiovascular disease (CVD) is inevitably higher for women going through early-stage breast cancer than those individuals without the cancer. The Framingham Risk Score (FRS) is a specific algorithm that estimates the risk of developing CVD within 10 years which is a survey that includes the risk factors of age, smoking status, cholesterol, HDL cholesterol, systolic blood pressure and blood pressure being treated with medicines . This is the only study to examine the effects of exercise on the FSC with patients going through early stage breast cancer.

The relationship between early stage pregnancy and cardiovascular disease has been poorly portrayed and understood by society until recent times. Researchers have recently discovered that women who have pre-eclampsia or gestational hypertension during pregnancy are at an increased risk of cardiovascular disease. This underpins the necessity for action to be take to prevent this disease from occurring . In California, studies conducted convey that breast cancer survivors are at an increased risk of cancer occurrence. These studies show that within 6-12 months post recovery, patients experience decreased cardiorespiratory function, depression and weight gain. This study assesses whether aerobic and resistance training can improve cardiovascular function with early stage breast cancer which will prevent disease in the future.

Where is the research from?

Kyuwan Lee, Debu Tripathy, Wendy Demark-Wahnefried, Kerry S. Courneya, Nathalie Sami, Leslie Bernstein, Darcy Spicer, Thomas A. Buchanan, Joanne E. Mortimer, and Christina M. Dieli-Conwright conducted their research at the integrative Center for Oncology Research in Exercise at USC(ICORE), between August 2012 to October 2018. The intervention protocol was reviewed and approved by the University of Southern California Institutional. The participants were recruited from Lee Breast Clinic at Norris Comprehensive Cancer Center, USC County Medical Center and from posting flyers at USC Health Science Campus. Despite the intervention being conducted in USA, the results are still relevant to Australians.

Kyuwan is a renowned author that has published over 20 peer-reviewed papers, he is a specialist in breast cancer re-occurrence, cardiovascular dysfunction and effects of aerobic and resistance training. The other authors have published many health studies, relating to breast cancer.

What kind of research was this?

This research classifies as a randomised controlled 16 week exercise intervention in which participants are randomly assigned into one of two groups. One group labelled as the experimental group receiving the intervention and the other being the control group , which is considered the standard they compare to.

What did the research involve?

100 women with breast cancer who are less than 6 months of post-treatment received Framingham Risk Score which calculate each women's 10 year estimated risk of CVD to determine baseline results. Then the participants were divided into two groups for testing, one group as the 'usual care' group and the other was the 'exercise intervention' group. The intervention was performed weekly for 16 weeks and after they received a Framingham Risk Score again. The exercise intervention included:

• At least 150 minutes of aerobic exercise per week. Activities included treadmill walking, rowing or cycling.
• Aerobic training was performed at 65-80% of maximum heart rate
• Two or Three days of resistance training per week. Exercises included leg presses, leg flexion's or extensions, chest presses, seated rows, bicep curls, and tricep pulldowns
• Resistance training was performed at 60-80% of 1 rep maximum and 3 sets of 10 reps on each exercise

Weekly Exercise Intervention Protocol

Day 1	Day 2	Day 3	Day 4	Day 5	Day 6	Day 7
Aerobic Exercise:50 minutes at 65-80% HR maximum;and Resistance Exercise: 3 sets of 10 repetitions, 45 second rest between sets	Rest	Aerobic Exercise:50 minutes at 65-80% HR maximum; and Resistance Exercise: 3 sets of 10 repetitions, 45 second rest between sets	Rest	Aerobic Exercise: 50 minutes at 65-80% HR maximum; No Resistance Exercise	Rest	Rest

Four women from the exercise intervention group were unreachable mid-way through the intervention. Four women discontinued the intervention from the casual care group and one was ineligible due to injury. There were 46 women from the exercise intervention group and 45 from the casual care group. Participants must of be a non smoker and previously been sedentary (Irregular physical activity, less than 60 minutes of physical activity per week)

What were the basic results?

The exercise intervention group recorded 95% attendance, after which there Framingham Risk Score (FRS) were recorded and the difference between the pre and post 14 week intervention was determined. As conveyed in the table below, the researchers reported that the total FRS scores decreased from 12.0 to 2.0 (P<0.05) in the exercise intervention group and the total FRS scores increased from 12.0 to 13.0 (P>0.05) in the usual care group. Overall the FRS was statistically significantly reduced (mean, −9.5; 95% CI, −13.0 to −6.0) in the exercise intervention group compared with usual care group.

Comparison of FRS Variables Between Exercise and Usual Care Groups

Variable (Group)	Baseline mean (SD)	Post-intervention mean (SD)	Post-intervention P value	Post-intervention Between-Group Difference Mean (95% CI)
Total FRS
Exercise intervention	12.0 (2.0)	2.0 (1.5)	<0.001	−9.5 (−13.0 to −6.0)
Usual care	12.0 (2.0)	13.0 (3.0)	0.67	−9.5 (−13.0 to −6.0)
FRS-predicted 10-y risk %
Exercise intervention	13.0 (3.0)	2.0 (0.5)	<0.001	−11.0 (−15.0 to −5.0)
Usual care	13.0 (3.0)	13.0 (3.0)	0.97	−11.0 (−15.0 to −5.0)

What conclusions can we take from this research?

The researchers report that resistant and aerobic training substantially reduce the risk of cardiovascular disease in women with early-stage breast cancer. It is evident that the 16 week training program significantly reduces the women's FRS within the intervention group. The lowered FRS was a result from the training decreasing low-density lipoprotein cholesterol, systolic blood pressure and increasing high-density lipoprotein cholesterol. Despite body weight or fitness level aerobic and resistance training are consequential in reducing the risk of cardiovascular disease.

Practical advice

Further research confirms that aerobic and resistant training not only lowers risk of cardiovascular disease within women with early-stage breast cancer but also for all individuals . Additionally study notes that not only exercise but diet plays an additional role in reducing the risk of cardiovascular disease . Progressively increasing either weight or reps/sets during resistance training and increasing speed or distance during aerobic training is important to improve fitness and is best monitored by a personal trainer. Often individuals experience a lack of energy or motivation to exercise which is why it's recommended to train with friends to make it more fun and enjoyable. Training with others is considered safer than training alone, in case of an emergency .

Further information/resources

Below are extra resources to provide additional information;

Associations of Pregnancy Complications With Calculated Cardiovascular Disease Risk and Cardiovascular Risk Factors in Middle Age

Framingham Risk Score for Hard Coronary Heart Disease

Comparative effectiveness of aerobic, resistance, and combined training on cardiovascular disease risk factors: A randomized controlled trial

Healthy Pregnant or Postpartum Women

References

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