Exercise type and fat mass loss regulate breast cancer-related sex hormones in obese and overweight postmenopausal women

The Association between Cardiorespiratory Fitness and the Risk of Breast Cancer in Women

INTRODUCTION

Studies have shown an inverse association between the risk of breast cancer in women and physical activity. However, information on the association between cardiorespiratory fitness (CRF) assessed objectively by a standardized test and the risk of developing breast cancer is limited.

PURPOSE

To examine the CRF-breast cancer risk association in healthy females.

METHODS

This retrospective study was derived from the Exercise Testing and Health Outcomes Study cohort ( n = 750,302). Female participants ( n = 44,463; mean age ± SD; 55.1 ± 8.9 yr) who completed an exercise treadmill test evaluation (Bruce protocol) at the Veterans Affairs Medical Centers nationwide from 1999 to 2020 were studied. The cohort was stratified into four age-specific CRF categories (Least-fit, Low-fit, Moderate-fit, and Fit), based on the peak METs achieved during the exercise treadmill test.

RESULTS

During 438,613 person-years of observation, 994 women developed breast cancer. After controlling for covariates, the risk of breast cancer was inversely related to exercise capacity. For each 1-MET increase in CRF, the risk of cancer was 7% lower (HR, 0.93; 95% CI, 0.90-0.95; P < 0.001). When risk was assessed across CRF categories with the Least-fit group as the referent, the risk was 18% lower for Low-fit women (HR, 0.82; 95% CI, 0.70-0.96; P = 0.013), 31% for Moderate-fit (HR, 0.69; 95% CI, 0.58-0.82; P < 0.001), and 40% for Fit (HR, 0.60; 95% CI, 0.47-0.75; P < 0.001).

CONCLUSIONS

We observed an inverse and graded association between CRF and breast cancer risk in women. Thus, encouraging women to improve CRF may help attenuate the risk of developing breast cancer.

The efficacy of exercise training for improving body composition in patients with breast cancer: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

To evaluate the efficacy of exercise in improving body composition in patients with breast cancer; the effects of exercise on weight and BMI were evaluated as secondary outcomes.

DATA SOURCES

Cochrane Library, EMBASE, PubMed and Web of Science were searched for randomized controlled trials published in English from database inception to 29 November 2023.

METHODS

The effects of exercise on body composition in patients with breast cancer were explored. After separately extracting the data, two reviewers assessed the overall quality of the evidence as well as the methodological quality of the included studies.

RESULTS

Fourteen studies with 1241 participants were included, of which 12 studies were eligible for meta-analysis. Exercise significantly reduced body fat (mean difference [MD], -0.33; 95% CI, -0.37 to -0.29; P < 0.00001) and increased lean mass (MD, 0.42; 95% CI, 0.34 to 0.49; P < 0.00001) in patients with breast cancer. Further, exercise intervention was associated with increased BMI of patients with breast cancer (MD, 0.03; 95% CI, 0.01 to 0.06; P = 0.01), while no significant difference in weight was detected between the exercise and the non-exercise groups. Subgroup analysis results showed that only resistance exercise reduced fat mass (MD, -0.22; 95% CI, -0.27 to -0.16; P < 0.00001).

CONCLUSIONS

Exercise effectively improves body composition in patients with breast cancer. Clinicians should encourage patients to engage in exercise and develop optimized exercise prescriptions.

Effects of Obesity and Calorie Restriction on Cancer Development

The risk of malignant tumor development is increasing in the world. Obesity is an established risk factor for various malignancies. There are many metabolic alterations associated with obesity which promote cancerogenesis. Excessive body weight leads to increased levels of estrogens, chronic inflammation and hypoxia, which can play an important role in the development of malignancies. It is proved that calorie restriction can improve the state of patients with various diseases. Decreased calorie uptake influences lipid, carbohydrate and protein metabolism, hormone levels and cell processes. Many investigations have been devoted to the effects of calorie restriction on cancer development in vitro and in vivo. It was revealed that fasting can regulate the activity of the signal cascades including AMP-activated protein kinase (AMPK), mitogen-activated protein kinase (MAPK), p53, mTOR, insulin/ insulin-like growth factor 1 (IGF1) and JAK-STAT. Up- or down-regulation of the pathways results in the decrease of cancer cell proliferation, migration and survival and the increase of apoptosis and effects of chemotherapy. The aim of this review is to discuss the connection between obesity and cancer development and the mechanisms of calorie restriction influence on cancerogenesis that stress the importance of further research of calorie restriction effects for the inclusion of this approach in clinical practice.

High-intensity interval training improves metabolic syndrome in women with breast cancer receiving Anthracyclines

INTRODUCTION

Anthracycline chemotherapy is a frequent treatment for breast cancer, whereas it can increase risk of physiologic side-effects, such as metabolic syndrome (MetS). Exercise has been used as a non-pharmacological strategy to decrease MetS. Specifically, high-intensity interval training (HIIT) has been shown to improve MetS in patients with diabetes or cardiac rehabilitation patients; however, the effects of HIIT on MetS and associated biomarkers in patients with breast cancer receiving anthracycline chemotherapy have not been previously explored. Therefore, we purposed to determine the effects of HIIT on MetS in breast cancer patients undergoing anthracycline chemotherapy.

METHODS

In total, 30 patients with breast cancer were recruited prior to initiating treatment and randomized into HIIT (n = 15) or control (n = 15). The HIIT group attended supervised cycling sessions 3 days/week for 8 weeks. MetS was assessed by waist circumference, blood pressure, fasting levels of high-density lipoprotein cholesterol (HDL-C), triglycerides, and glucose. Circulating levels of MetS-related biomarkers were also measured (total cholesterol, insulin, HbA1c, leptin, adiponectin, and c-reactive protein).

RESULTS

After 8 weeks, MetS z-score was significantly improved in the HIIT group compared with controls (-7.60, 95% CI: -9.08 to -6.13, p < 0.001). MetS variables (HDL-C, glucose, and triglycerides) and circulating levels of MetS-related biomarkers were significantly improved in the HIIT group compared with controls (p < 0.001). Non-significant differences were found in body composition outcomes at the end of the study.

CONCLUSIONS

HIIT may be an effective strategy to improve MetS in breast cancer patients undergoing anthracycline chemotherapy. Furthermore, changes in MetS were independent of changes in body composition.

Combined effect of physical exercise and hormone replacement therapy on cardiovascular and metabolic health in postmenopausal women: A systematic review and meta-analysis

The cardioprotective effect of postmenopausal hormone replacement therapy (HRT) has been demonstrated in several studies. Similarly, physical exercise has yielded positive results. However, the effects of their combination remain inconclusive. This review describes the combined effects of physical exercise and hormone therapy on cardiovascular and metabolic health in postmenopausal women. We searched the Scopus, Web of Science, PubMed, and Embase databases and included randomized controlled trials published up to December 2021 on the combined effects of physical exercise and hormone therapy on cardiovascular and metabolic health in postmenopausal women. We identified 148 articles, of which only seven met the inclusion criteria (386 participants; 91 [23%] HRT + exercise; 104 [27%] HRT; 103 [27%] exercise; 88 [23%] placebo). The combined treatment further decreased systolic blood pressure (SBP) compared to the isolated effect of aerobic training (AT) (mean difference [MD]=-1.69; 95% confidence interval [CI]=-2.65 to -0.72, n=73). Nevertheless, it attenuated the decrease in diastolic blood pressure (DBP) (MD=0.78; 95%CI: 0.22-1.35, n=73), and the increase in peak oxygen consumption (VO2 peak) promoted by exercise (AT + HRT=2.8±1.4 vs AT + placebo=5.8±3.4, P=0.02). The combination of AT and oral HRT improved SBP. However, AT alone seemed to have a better effect on physical fitness and DBP in postmenopausal women.

Examining the Role of Physical Activity Interventions in Modulating Androgens and Cardiovascular Health in Postmenopausal Women: A Narrative Review

A growing body of literature has examined the role of physical activity (PA) in modifying the effects of estrogen withdrawal on cardiovascular health in postmenopausal women, but the impact of PA on androgens is less clear. Changes in androgen concentrations following regular PA may improve cardiovascular health. This narrative review summarizes the literature assessing the impact of PA interventions on androgens in postmenopausal women. The association between changes in androgen concentrations and cardiovascular health following PA programs is also examined. Randomized controlled trials were included if they (i) implemented a PA program of any type and duration in postmenopausal women and (ii) measured changes in androgen concentrations. Following PA interventions, no changes in androstenedione, conflicting changes in dehydroepiandrosterone/dehydroepiandrosterone-sulfate, and increases in sex hormone-binding globulin concentrations were found. Total testosterone decreased following aerobic PA but increased after resistance training. Most aerobic PA interventions led to reductions in free testosterone. A combination of caloric restriction and/or fat loss enhanced the influence of PA on most androgens. Evidence exploring the relationship between changes in androgens and cardiovascular health indicators was scarce and inconsistent. PA has shown promise in modifying the concentrations of some androgens (free and total testosterone, sex hormone-binding globulin), and remains a well-known beneficial adjuvant option for postmenopausal women to manage their cardiovascular health. Fat loss influences the effect of PA on androgens, but the synergistic role of PA and androgens on cardiovascular health merits further examination. Many research gaps remain regarding the relationship between PA, androgens, and cardiovascular disease in postmenopausal women.

Exercise training and detraining effects on body composition, muscle strength and lipid, inflammatory and oxidative markers in breast cancer survivors under tamoxifen treatment

AIMS

The present study aimed to verify the effects of resistance training (RT) and successive detraining on body composition, muscle strength and lipid profile as primary outcome, and the oxidative stress and inflammatory markers as second outcome of postmenopausal Breast Cancer (BC) survivors undergoing tamoxifen (TA).

MAIN METHODS

Fourteen postmenopausal BC survivors underwent 12 weeks of resistance exercise training and subsequently 12 weeks of detraining. Anthropometric parameters, lipid profile, muscle strength, inflammatory cytokines and the oxidative stress markers, were assessed before, after the training period and after detraining period.

KEY FINDINGS

One-way ANOVA showed that fat mass decrease (39.4 ± 6.9 to 37.7 ± 6.8%) and free-fat mass increase (39.3 ± 4.9 to 40.3 ± 5.6%) after RT. Muscle strength increased in response to training but decreased after the detraining period. Triglycerides (156 ± 45 to 123 ± 43 mg/dL) and total cholesterol (202 ± 13 to 186 ± 16 mg/dL) decreased after the RT and HDL-cholesterol (47 ± 9 to 56 ± 9 mg/dL) increased after RT and remained higher (53 ± 10 mg/dL) than after detraining. IL-6 increases (24.65 ± 10.85 to 41.42 ± 22.88 pg/mL) and IL-17 (2.42 ± 0.32 to 1.69 ± 0.19 pg/mL), TBARS (1.91 ± 0.19 to 1.03 ± 0.1 μmol/L), SOD (24.65 ± 10.85 to 41.42 ± 22.88 U/gHb) and Catalase activity (445.9 ± 113.0 to 345.8 ± 81.7 k/gHb·s) reduced after RT and remained lower after detraining.

SIGNIFICANCE

Resistance exercise training improves health markers of BC survivors undergoing TA and detraining are not sufficient to reverse the positive effects in oxidative stress markers.

Effects of Circuit Resistance Training on Body Composition, Strength, and Cardiorespiratory Fitness in Middle-Aged and Older Women: A Systematic Review and Meta-Analysis

A systematic review with meta-analysis was conducted to evaluate the effects of circuit resistance training (CRT) on cardiorespiratory fitness, strength, and body composition in middle-aged and older women. Sixteen studies were included in the meta-analysis. The CRT interventions led to a significant decrease in weight, body mass index, and fat mass along with an increase in muscle mass. Significant differences were found in the fat mass and a trend to develop muscle mass when compared with the control group. CRT led to a significant increase in VO2max, walking endurance, and time to exhaustion; likewise, significant differences were observed when compared with the control group. CRT had a moderate and large favorable effect on arm, trunk, and lower limb strength. Furthermore, the increases in strength observed in the CRT were significantly greater than the changes observed in the control group. In middle-aged and older women, CRT improved cardiorespiratory fitness and strength and optimized body composition.

The poorly conducted orchestra of steroid hormones, oxidative stress and inflammation in frailty needs a maestro: Regular physical exercise

This review outlines the various factors associated with unhealthy aging which includes becoming frail and dependent. With many people not engaging in recommended exercise, facilitators and barriers to engage with exercise must be investigated to promote exercise uptake and adherence over the lifespan for different demographics, including the old, less affluent, women, and those with different cultural-ethnic backgrounds. Governmental and locally funded public health messages and environmental facilitation (gyms, parks etc.) can play an important role. Studies have shown that exercise can act as a conductor to balance oxidative stress, immune and endocrine functions together to promote healthy aging and reduce the risk for age-related morbidities, such as cardiovascular disease and atherosclerosis, and promote cognition and mood over the lifespan. Like a classic symphony orchestra, consisting of four groups of related musical instruments - the woodwinds, brass, percussion, and strings - the aging process should also perform in harmony, with compassion, avoiding the aggrandizement of any of its individual parts during the presentation. This review discusses the wide variety of molecular, cellular and endocrine mechanisms (focusing on the steroid balance) underlying this process and their interrelationships.

Estrogen-Receptor-Positive Breast Cancer in Postmenopausal Women: The Role of Body Composition and Physical Exercise

Breast cancer (BC) is the most commonly diagnosed cancer among women worldwide and the most common cause of cancer-related death. To date, it is still a challenge to estimate the magnitude of the clinical impact of physical activity (PA) on those parameters producing significative changes in future BC risk and disease progression. However, studies conducted in recent years highlight the role of PA not only as a protective factor for the development of ER+ breast cancer but, more generally, as a useful tool in the management of BC treatment as an adjuvant to traditional therapies. In this review, we focused our attention on data obtained from human studies analyzing, at each level of disease prevention (i.e., primary, secondary, tertiary and quaternary), the positive impact of PA/exercise in ER+ BC, a subtype representing approximately 70% of all BC diagnoses. Moreover, given the importance of estrogen receptors and body composition (i.e., adipose tissue) in this subtype of BC, an overview of their role will also be made throughout this review.

Circulating myokines IL-6, IL-15 and FGF21 response to training is altered by exercise type but not by menopause in women with obesity

To examine the effects of a time-matched endurance vs. concurrent training on circulating IL-6, IL-13, IL-15, IL-15Ra, FGF21 levels in postmenopausal women with obesity, and to determine these myokines response to endurance training pre- and postmenopause. Thirty-five sedentary postmenopausal women with obesity were randomly divided into endurance training (EN1, N = 10), concurrent training (CON, N = 13) or no training group (CT, N = 12). Additionally, twelve sedentary premenopausal women with obesity were added to an endurance training group (EN2, N = 12). Participants took part in a 12-week supervised intervention, performing 3 sessions/week of 60 min/session. Before and after the interventions, body composition and fitness were assessed, and blood samples obtained to measure serum myokines levels. Total fat mass decreased in all exercised groups (CON,-5.2%; EN1,-5.3%; EN2,-5.6%). In postmenopausal women, serum IL-6, IL-15 and IL-15Ra decreased after training (P<0.01), finding a pronounced reduction in IL-6 (-42% vs. -16%) and IL-15 (-50% vs. -31%) when comparing EN1 to CON (P<0.05). Serum FGF21 was only reduced in the EN1 (-27%; P=0.012). While EN1 and EN2 comparison, reported differences for IL-15Rα concentration (-28% vs. -40%; P=0.023). Finally, in EN2, the delta change of fat mass and IL-6, IL-15 and IL-15Rα were associated (r = 0.605; r = 0.546; r = 0.515; P<0.05). IL-13 showed undetected concentrations. Circulating IL-6, IL-15 and FGF21 response to training is altered by exercise type but not by menopause in women with obesity. Endurance training promotes a higher reduction of these myokines, potentially activating their intricate immune and fat mass regulation roles in postmenopausal women with obesity.

Dose-response effects of aerobic exercise on adiposity markers in postmenopausal women: pooled analyses from two randomized controlled trials

BACKGROUND/OBJECTIVE

Exercise may reduce the risk of breast cancer through adiposity changes, but the dose-response effects of exercise volume on adiposity markers are unknown in postmenopausal women. We aimed to compare the dose-response effects of prescribed aerobic exercise volume on adiposity outcomes.

PARTICIPANTS/METHODS

Data from the Alberta Physical Activity and Breast Cancer Prevention (ALPHA) and Breast Cancer and Exercise Trial in Alberta (BETA) were pooled for this analysis (N = 720). These were 12-month randomized controlled trials, where participants were randomized to 225 min/week (mid-volume) of aerobic exercise versus usual inactive lifestyle (ALPHA), or 150 min/week (low-volume) versus 300 min/week (high-volume) (BETA). Fat mass and fat-free mass were measured using DXA and intra-abdominal and subcutaneous fat area were assessed with computed tomography.

RESULTS

After 12 months of aerobic exercise, increasing exercise volumes from no exercise/control to 300 min/week resulted in statistically significant reductions in BMI, weight, fat mass, fat percentage, intra-abdominal and subcutaneous fat area (P < 0.001). Compared with controls, fat mass loss was -1.13, -1.98 and -2.09 kg in the low-, mid- and high-volume groups, respectively. Similarly, weight loss was -1.47, -1.83, -2.21 kg in the low-, mid- and high-volume groups, respectively, compared to controls, and intra-abdominal fat area loss was -7.44, -15.56 and -8.76 cm² in the low-, mid- and high-volume groups, respectively, compared to controls. No evidence for a dose-response effect on fat-free mass was noted.

CONCLUSION

A dose-response effect of exercise volume on adiposity markers was noted, however, the differences in adiposity markers were smaller when comparing 225 min/week to 300 min/week of exercise. Given the strong positive associations between obesity and postmenopausal breast cancer risk, this study provides evidence on the importance of exercise volume as part of the exercise prescription to reduce adiposity and, ultimately, postmenopausal breast cancer risk.

Weight Regain and Breast Cancer-Related Biomarkers Following an Exercise Intervention in Postmenopausal Women

BACKGROUND

Epidemiologic studies have reported associations between weight fluctuations and postmenopausal breast cancer risk; however, the biological markers involved in this association are unknown. This study aimed to explore the associations between breast cancer-related biomarkers and weight regain following exercise-induced weight loss.

METHODS

From the 400 participants included in the Breast Cancer and Exercise Trial in Alberta, a total of 214 lost weight during the intervention and had follow-up blood samples, body composition, and covariate measurements. Outcomes were measured at baseline, 12 months (end of the study), and 24 months (follow-up).

RESULTS

During follow-up, weight regain was 1.80 kg [95% confidence interval (CI): -0.40-3.90], and was significantly associated with increases in estradiol [treatment effect ratio (TER) = 1.03; 95% CI, 1.01-1.04], estrone (TER = 1.02; 95% CI, 1.01-1.03), free estradiol (TER = 1.04; 95% CI, 1.02-1.05), the homeostatic model assessment for insulin resistance (TER = 1.03; 95% CI, 1.02-1.05), and insulin (TER = 1.03; 95% CI, 1.01-1.04), and decreases in sex hormone-binding globulin (SHBG; TER = 0.98; 95% CI, 0.97-0.99) levels. Nonstatistically significant associations were found for glucose and C-reactive protein. Furthermore, a statistically significant linear trend of increasing levels for all biomarkers, and decreasing SHBG, across weight regain categories was found.

CONCLUSIONS

These results suggest that weight regain following exercise-induced weight loss is associated with breast cancer-related biomarker changes in postmenopausal women.

IMPACT

These findings provide evidence to support the importance of developing effective strategies to prevent weight regain and, consequently, decrease postmenopausal breast cancer risk via changes in adiposity-related biomarkers.

The Effects of Diet and Exercise on Endogenous Estrogens and Subsequent Breast Cancer Risk in Postmenopausal Women

Endogenous estrogens have been associated with overall breast cancer risk, particularly for postmenopausal women, and ways to reduce these estrogens have served as a primary means to decrease overall risk. This narrative review of clinical studies details how various nutritional and exercise lifestyle interventions have been used to modify estrogen levels and metabolism to provide a protective impact against breast cancer incidence. We also summarized the evidence supporting the efficacy of interventions, outcomes of interest and identified emerging research themes. A systematic PubMed MEDLINE search identified scholarly articles or reviews published between 2000-2020 that contained either a cohort, cross-sectional, or interventional study design and focused on the relationships between diet and/or exercise and overall levels of different forms of estrogen and breast cancer risk and occurrence. Screening and data extraction was undertaken by two researchers. Data synthesis was narrative due to the heterogeneous nature of studies. A total of 1625 titles/abstracts were screened, 198 full texts reviewed; and 43 met eligibility criteria. Of the 43 studies, 28 were randomized controlled trials, and 15 were observational studies. Overall, studies that incorporated both diet and exercise interventions demonstrated better control of detrimental estrogen forms and levels and thus likely represent the best strategies for preventing breast cancer development for postmenopausal women. Some of the strongest associations included weight loss via diet and diet + exercise interventions, reducing alcohol consumption, and consuming a varied dietary pattern, similar to the Mediterranean diet. More research should be done on the effects of specific nutritional components on endogenous estrogen levels to understand the effect that the components have on their own and in combination within the diet.