Poor diet quality has been associated with an increased risk of cancer. Here, we examine the association between dietary patterns derived with two methods, and combined and site-specific cancer ...incidence in Canada.
Dietary data were obtained from participants enrolled in Alberta's Tomorrow Project, a prospective cohort study, between 2000 and 2008. Principle component analysis (PCA) and reduced rank regression (RRR) were used to derive dietary patterns, and data linkage with the Alberta Cancer Registry was used for incident cancer cases. Cox proportional hazard regressions were used to estimate multivariable-adjusted models for the association between each dietary pattern score with combined and site-specific cancer incidence.
PCA revealed three dietary patterns ("western", "prudent", and "sugar, fruits, and dairy") and RRR resulted in four patterns ("dietary fiber", "vitamin D", "fructose", and "discretionary fat"). Five cancer sites were included in our site-specific analysis: lung, colon, breast, prostate, and endometrial cancers. The most protective dietary patterns for combined cancer sites were the "Prudent" pattern (HR = 0.82, CI = 0.73-0.92) and the "Dietary fiber" pattern (HR = 0.82, CI = 0.69-0.97). The "Fructose" pattern was associated with increased risk of combined cancers (HR = 1.14, CI = 1.02-1.27). Three dietary patterns were protective against colon cancer ("Prudent", "Dietary fiber", and "Discretionary fats"), and other risk reductions were seen for the "sugar, fruit, and dairy" pattern (lung cancer), and the "Dietary fiber" pattern (prostate cancer).
These results support cancer prevention strategies for a diet high in vegetables, fruits, fish, and whole grains. Further studies should explore the possible association between discretionary fats and colon cancer.
The aim of this study was to evaluate associations between pre- and postdiagnosis physical activity and survival in survivors of endometrial cancer by physical activity domain, intensity, dose ...(metabolic-equivalent task MET-hours/week/year), and change from pre- to postdiagnosis.
We conducted a prospective cohort study in Alberta, Canada, of 425 women who were diagnosed with histologically confirmed invasive endometrial cancer between 2002 and 2006 and observed to 2019. The interviewer-administered Lifetime Total Physical Activity Questionnaire recorded prediagnosis (assessed at a median of 4.4 months after diagnosis) and postdiagnosis physical activity (assessed at a median of 3.4 years after diagnosis). Associations between physical activity and overall and disease-free survival were assessed using Cox proportional hazards models adjusted for age, stage, grade, treatments, body mass index, menopausal status, hormone therapy use, family history of cancer, and comorbidities.
After a median follow-up of 14.5 years, there were 60 deaths, including 18 endometrial cancer deaths, and 80 disease-free survival events. Higher prediagnosis recreational physical activity was statistically significantly associated with improved disease-free survival (> 14
≤ 8 MET-hours/week/year; hazard ratio HR, 0.54; 95% CI, 0.30 to 0.96;
= .04), but not overall survival (HR, 0.56; 95% CI, 0.29 to 1.07;
= .06). Higher postdiagnosis recreational physical activity (> 13
≤ 5 MET-hours/week/year) was strongly associated with both improved disease-free survival (HR, 0.33; 95% CI, 0.17 to 0.64;
= .001) and overall survival (HR, 0.33; 95% CI, 0.15 to 0.75;
= .007). Participants who maintained high recreational physical activity levels from pre- to postdiagnosis also had improved disease-free survival (HR, 0.35; 95% CI, 0.18 to 0.69) and overall survival (HR, 0.43; 95% CI, 0.20 to 0.94) compared with those who maintained low physical activity levels.
Recreational physical activity, especially postdiagnosis, is associated with improved survival in survivors of endometrial cancer.
Objective
Exercise is recommended for polycystic ovary syndrome (PCOS), but the most effective exercise prescription is unclear. This trial compared effects of high‐intensity interval training ...(HIIT), continuous aerobic exercise training (CAET) and no‐exercise control on reproductive, anthropometric and cardiometabolic outcomes in PCOS.
Design
Pilot randomized controlled trial.
Participants
Previously inactive women aged 18–40 years with PCOS.
Measurements
Feasibility outcomes included recruitment, retention, adherence to exercise and daily ovulation prediction kit (OPK) testing. Preliminary efficacy outcomes included reproductive, anthropometric and cardiometabolic health markers.
Results
Forty‐seven women were randomized to no‐exercise control (n = 17), HIIT (n = 16), or CAET (n = 14). Forty (85%) participants completed the trial. Median exercise adherence was 68% (IQR 53%, 86%). Median daily OPK‐testing adherence in the first half of the intervention was 87% (IQR 61%, 97%) compared with 65% (IQR 0%, 96%) in the second half. Body mass index decreased significantly in CAET compared with control (−1.0 kg/m2, p = .01) and HIIT (−0.9 kg/m2, p = .04). Mean waist circumference decreased in all groups (−7.3 cm, −6.9 cm, −4.5 cm in HIIT, CAET and control) with no significant between‐group differences. Mean LDL‐C was significantly reduced for HIIT compared to CAET (−0.33 mmol/L, p = .03). HDL‐C increased in HIIT compared with control (0.18 mmol/L, p = .04).
Conclusions
There were feasibility challenges with adherence to daily ovulation assessment limiting the ability to analyse the effect of the exercise interventions on ovulation. CAET and HIIT were both effective at improving anthropometrics and some cardiometabolic health markers. Further studies need to determine optimal and acceptable exercise prescriptions for this population.
The Combined Aerobic and Resistance Exercise (CARE) Trial compared different types and doses of exercise performed during breast cancer chemotherapy. Here, we report the longer‐term follow‐up of ...patient‐reported outcomes, health‐related fitness and exercise behavior at 6, 12 and 24 months postintervention. A multicenter trial in Canada randomized 301 breast cancer patients initiating chemotherapy to thrice weekly, supervised exercise consisting of a standard dose of 25–30 min of aerobic exercise (STAN; n = 96), a higher dose of 50–60 min of aerobic exercise (HIGH; n = 101) or a combined dose of 50–60 min of aerobic and resistance exercise (COMB; n = 104) performed for the duration of chemotherapy (median of 17 weeks). Primary outcomes were patient‐reported outcomes including quality of life, cancer‐related symptoms and psychosocial outcomes. Secondary outcomes were objective health‐related fitness (assessed at 12 months only) and self‐reported exercise behavior. A total of 269 (89.4%) participants completed patient‐reported outcomes at all three follow‐up time points and 263 (87.4%) completed the health‐related fitness assessment at 12‐month follow‐up. COMB was significantly superior to (i) STAN for sleep quality at 6‐month follow‐up (p = 0.027); (ii) HIGH for upper body muscular endurance at 12‐month follow‐up (p = 0.020); and (iii) HIGH for meeting the resistance exercise guideline at 6‐month follow‐up (p = 0.006). Moreover, self‐reported meeting of the combined exercise guideline during follow‐up was significantly associated with better patient‐reported outcomes and health‐related fitness. Performing combined exercise during and after breast cancer chemotherapy may result in better longer‐term patient‐reported outcomes and health‐related fitness compared to performing aerobic exercise alone.
What's new?
While exercise during chemotherapy for breast cancer is associated with various improvements in patient health, including improved quality of life, it remains unclear what type and dose of exercise is most beneficial over the long term. Here, the long‐term effects of different exercise regimens on patient health were compared among stage I‐IIIc breast cancer patients initiating adjuvant chemotherapy. Relative to aerobic exercise alone, combined aerobic and resistance exercise yielded the greatest benefits for patients, both during and after chemotherapy. In particular, combined aerobic and resistance exercise was associated with superior upper and lower body muscular endurance and improved sleep quality.
Few Canadian studies have examined whether or not associations between neighbourhood walkability and physical activity differ by sex. We estimated associations between perceived neighbourhood ...walkability and physical activity among Canadian men and women. This study included cross-sectional survey data from participants in ‘Alberta's Tomorrow Project’ (Canada; n = 14,078), a longitudinal cohort study. The survey included socio-demographic items as well as the International Physical Activity Questionnaire (IPAQ) and the abbreviated Neighbourhood Environment Walkability Scale (NEWS-A), which captured perceived neighbourhood built characteristics. We computed subscale and overall walkability scores from NEWS-A responses. Covariate-adjusted generalized linear models estimated the associations of participation (≥10 min/week) and minutes of different types of physical activity, including transportation walking (TW), leisure walking (LW), moderate-intensity physical activity (MPA), and vigorous-intensity physical activity (VPA) with walkability scores. Walkability was positively associated with participation in TW, LW, MPA and VPA and minutes of TW, LW, and VPA. Among men, a negative association was found between street connectivity and VPA participation. Additionally, crime safety was negatively associated with VPA minutes among men. Among women, pedestrian infrastructure was positively associated with LW participation and overall walkability was positively associated with VPA minutes. Notably, overall walkability was positively associated with LW participation among men and women. Different perceived neighbourhood walkability characteristics might be associated with participation and time spent in different types of physical activity among men and women living in Alberta. Interventions designed to modify perceptions of neighbourhood walkability might influence initiation or maintenance of different types of physical activity.
•Perceived walkability was associated with participation in different physical activities.•Perceived walkability was associated with minutes of different physical activities.•Among women, perceived pedestrian infrastructure was associated with physical activity.•Among men, perceived street connectivity and crime safety were associated with physical activity.•Perceptions of the neighbourhood built environment may shape physical activity patterns.
We examined how an aerobic exercise intervention influenced circulating estradiol, estrone, sex hormone-binding globulin (SHBG), androstenedione, and testosterone levels, which may be involved in the ...association between physical activity and breast cancer risk.
A two-center, two-arm randomized controlled trial of exercise was conducted in 320 postmenopausal, sedentary women age 50 to 74 years. Participants were randomly assigned to a 1-year aerobic exercise intervention of 225 min/wk (n = 160) or to a control group who maintained their usual level of activity (n = 160). Baseline, 6-month, and 12-month assessments of estrone, estradiol, androstenedione, and testosterone were quantified by radioimmunoassay after extraction, and SHBG was quantified by an immunometric assay. Intent-to-treat analyses were performed using linear mixed models.
Blood data were available on 309 women (96.6%) at 12 months. Women in the intervention group exercised an average of 3.6 d/wk for 178 min/wk. At 12 months, statistically significant reductions in estradiol (treatment effect ratio TER = 0.93; 95% CI, 0.88 to 0.98) and free estradiol (TER = 0.91; 95% CI, 0.87 to 0.96) and increases in SHBG (TER = 1.04; 95% CI, 1.02 to 1.07) were observed in the exercise group compared with the control group. No significant differences in estrone, androstenedione, and testosterone levels were observed between exercisers and controls at 12 months.
This trial found that previously sedentary postmenopausal women can adhere to a moderate- to vigorous-intensity exercise program that results in changes in estradiol and SHBG concentrations that are consistent with a lower risk for postmenopausal breast cancer.
The benefit of physical activity (PA) for increasing longevity is well-established, however, the impact of diurnal timing of PA on mortality remains poorly understood. We aimed to derive circadian PA ...patterns and investigate their associations with all-cause mortality.
We used 24 h PA time series from 96,351 UK Biobank participants aged between 42 and 79 years at accelerometry in 2013-2015. Functional principal component analysis (fPCA) was applied to obtain circadian PA patterns. Using multivariable Cox proportional hazard models, we related the loading scores of these fPCs to estimate risk of mortality.
During 6.9 years of follow-up, 2,850 deaths occurred. Four distinct fPCs accounted for 96% of the variation of the accelerometry data. Using a loading score of zero (i.e., average overall PA during the day) as the reference, a fPC1 score of + 2 (high overall PA) was inversely associated with mortality (Hazard ratio, HR = 0.91; 95% CI: 0.84-0.99), whereas a score of -2 (low overall PA) was associated with higher mortality (1.69; 95% CI: 1.57-1.81; p for non-linearity < 0.001). Significant inverse linear associations with mortality were observed for engaging in midday PA instead of early and late PA (fPC3) (HR for a 1-unit increase 0.88; 95% CI: 0.83-0.93). In contrast, midday and nocturnal PA instead of early and evening PA (fPC4) were positively associated with mortality (HR for a 1-unit increase 1.16; 95% CI: 1.08-1.25).
Our results suggest that it is less important during which daytime hours one is active but rather, to engage in some level of elevated PA for longevity.
Physical inactivity increases postmenopausal and possibly premenopausal breast cancer risk, although different biologic mechanisms are proposed. Our primary objective was to estimate breast cancer ...risk associated with high versus low levels of moderate-vigorous recreational activity, separately for premenopausal and postmenopausal women.
We conducted a systematic review of literature published to July 2015. Included reports were cohort or case-control studies relating moderate-vigorous recreational physical activity (metabolic equivalent ≥3.0) to breast cancer incidence, exclusively (≥90%) in premenopausal or postmenopausal women. We appraised study quality and performed meta-analyses using random effects modeling. Subgroup meta-analyses were based on tumor subtype, race, body mass index, parity, hormone therapy use, family history of cancer, and statistical adjustment for body fatness. Dose-response relations were examined.
Pooled relative risks (RRs, 95% CI) for women with higher versus lower levels of moderate-vigorous recreational activity were RR = 0.80 (0.74-0.87) and RR = 0.79 (0.74-0.84) for premenopausal (43 studies) and postmenopausal (58 studies) breast cancer, respectively, with high heterogeneity. Inverse associations were weaker among postmenopausal cohort studies (RR = 0.90 0.85-0.95) and studies that statistically adjusted for nonrecreational (eg, occupational, household) activity (RR = 0.91 0.77-1.06 premenopausal, RR = 0.96 0.86-1.08 postmenopausal). Risk estimates with versus without body fatness adjustment did not vary by menopause status, although other subgroup effects were menopause-dependent. Among studies of overweight/obese women, there was an inverse association with postmenopausal but not premenopausal breast cancer (RR = 0.88 0.82-0.95 and RR = 0.99 0.98-1.00, respectively). Dose-response curves were generally nonlinear.
Although risk estimates may be similar for premenopausal and postmenopausal breast cancer, subgroup effects may be menopause-dependent.
Physical activity is a known modifiable lifestyle means for reducing postmenopausal breast cancer risk, but the biologic mechanisms are not well understood. Metabolic factors may be involved. In this ...study, we aimed to determine the effects of exercise on insulin resistance (IR) indicators, IGF1, and adipokines in postmenopausal women. The Alberta Physical Activity and Breast Cancer Prevention Trial was a two-armed randomized controlled trial in postmenopausal, inactive, cancer-free women. A year-long aerobic exercise intervention of 225 min/week (n=160) was compared with a control group asked to maintain usual activity levels (n=160). Baseline, 6- and 12-month serum levels of insulin, glucose, IGF1, IGF-binding protein 3 (IGFBP3), adiponectin, and leptin were assayed, and after data collection, homeostasis model assessment of IR (HOMA-IR) scores were calculated. Intention-to-treat analyses were performed using linear mixed models. The treatment effect ratio (TER) of exercisers to controls was calculated. Data were available on 308 (96.3%) women at 6 months and 310 (96.9%) women at 12 months. Across the study period, statistically significant reductions in insulin (TER=0.87, 95% confidence interval (95% CI)=0.81-0.93), HOMA-IR (TER=0.86, 95% CI=0.80-0.93), and leptin (TER=0.82, 95% CI=0.78-0.87), and an increase in the adiponectin/leptin ratio (TER=1.21, 95% CI=1.13-1.28) were observed in the exercise group compared with the control group. No significant differences were observed for glucose, IGF1, IGFBP3, adiponectin or the IGF1/IGFBP3 ratio. Previously inactive postmenopausal women who engaged in a moderate-to-vigorous intensity exercise program experienced changes in insulin, HOMA-IR, leptin, and adiponectin/leptin that might decrease the risk for postmenopausal breast cancer.
In 2020, the World Health Organization (WHO) released global guidelines on physical activity (PA) and sedentary behavior, for the first time providing population-based recommendations for people ...living with selected chronic conditions. This article briefly presents the guidelines, related processes and evidence, and, importantly, considers how they may be used to support research, practice, and policy.
A brief overview of the scope, agreed methods, selected chronic conditions (adults living with cancer, hypertension, type 2 diabetes, and human immunodeficiency virus), and appraisal of systematic review evidence on PA/sedentary behavior is provided. Methods were consistent with World Health Organization protocols for developing guidelines.
Moderate to high certainty evidence (varying by chronic condition and outcome examined) supported that PA can reduce the risk of disease progression or premature mortality and improve physical function and quality of life in adults living with chronic conditions. Direct evidence on sedentary behavior was lacking; however, evidence extrapolated from adult populations was considered applicable, safe, and likely beneficial (low certainty due to indirectness).
Clinical and public health professionals and policy makers should promote the World Health Organization 2020 global guidelines and develop and implement services and programs to increase PA and limit sedentary behavior in adults living with chronic conditions.
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