Abstract P3-08-17: Objectively measured physical activity in breast cancer survivors

Background: Obesity and physical inactivity are poor prognostic indicators for breast cancer (BC). Cardiorespiratory fitness (VO2max) is a good predictor of survival. Despite preserved LVEF, cardiorespiratory function is impaired in women with breast cancer after the completion of adjuvant therapy. International organizations recommend at least 150 minutes per week of moderate-vigorous physical activity (MVPA). Some studies show that a minority of cancer survivors are meeting the PA recommendations. A limitation of physical activity (PA) research has been the use of self-reported measures.

Eligibility criteria: 1) Age 18-79, 2) Able to walk a mile, 3) More than one year from diagnosis, 4) More than 3 months since the last therapy, 5) No evidence of disease.

Aims: Objective assessment of physical activity in breast cancer survivors. Adherence to international recommendations.

Material and methods: PA was evaluated through accelerometry (600 minutes per day, 5 days per week, 2 week-end days were required to consider as valid accelerometry values). Cardiorespiratory fitness was assessed through the “one-mile test”.

Results: 92 women (W) with BC history were included. 86 W were evaluable for accelerometry. 85 W were evaluable for VO2max. Age: 54.02 years (33-77), BMI: 27.89 (SD 8.89), waist perimeter: 89.74 cm (SD 17.37), median time from diagnosis 3.94 years, treatment with anthracyclines 55 W (63.9%), radiotherapy 69 W (80.23%). Accelerometry (86W): Average weekly time MVPA 351.14 min/wk (SD: 168.98). 76 (88%) met international recommendations of PA. Women previously treated with anthracyclines (47 W; 340.25 min/wk), radiotherapy (59 w; 343 min/wk) and both (48 W; 331 min/wk) exercised less than women who did not receive these therapies (8 W; 386 min/wk). This association was not statistically significant.

Average VO2max was 24.8 ml/kg/min (SD: 7.6).There was a significant effect of anthracyclines for VO2 max. Women not treated with anthracyclines had a VO2max: 26.41 whereas treated W had VO2max 22.08 ml/kg/min.

Discussion: A cohort of Spanish women met international recommendations of PA when it was objectively assessed. This cohort exhibited a poor cardiometabolic and cardiorespiratory profile. Previous exposure to anthracyclines predicted a poorer cardiorespiratory fitness. Specific research to investigate the role of exercise to mitigate that dysfunction in breast cancer survivors is warranted.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-08-17.

Actigraph GT3X: validation and determination of physical activity intensity cut points

The aims of this study were: to compare energy expenditure (EE) estimated from the existing GT3X accelerometer equations and EE measured with indirect calorimetry; to define new equations for EE estimation with the GT3X in youth, adults and older people; and to define GT3X vector magnitude (VM) cut points allowing to classify PA intensity in the aforementioned age-groups. The study comprised 31 youth, 31 adults and 35 older people. Participants wore the GT3X (setup: 1-s epoch) over their right hip during 6 conditions of 10-min duration each: resting, treadmill walking/running at 3, 5, 7, and 9 km · h⁻¹, and repeated sit-stands (30 times · min⁻¹). The GT3X proved to be a good tool to predict EE in youth and adults (able to discriminate between the aforementioned conditions), but not in the elderly. We defined the following equations: for all age-groups combined, EE (METs)=2.7406+0.00056 · VM activity counts (counts · min⁻¹)-0.008542 · age (years)-0.01380 ·  body mass (kg); for youth, METs=1.546618+0.000658 · VM activity counts (counts · min⁻¹); for adults, METs=2.8323+0.00054 · VM activity counts (counts · min⁻¹)-0.059123 · body mass (kg)+1.4410 · gender (women=1, men=2); and for the elderly, METs=2.5878+0.00047 · VM activity counts (counts · min⁻¹)-0.6453 · gender (women=1, men=2). Activity counts derived from the VM yielded a more accurate EE estimation than those derived from the Y-axis. The GT3X represents a step forward in triaxial technology estimating EE. However, age-specific equations must be used to ensure the correct use of this device.

Factors affecting gross efficiency in cycling

There is little standardization of how to measure cycling gross efficiency (GE). Therefore, the purposes of these studies were to evaluate the effect of: i) stage duration, ii) relative exercise intensity, iii) work capacity and iv) a prior maximal incremental test on GE. Trained subjects (n=28) performed incremental tests with stage durations of 1-, 3-, and 6-min to establish the effect of stage duration and relative exercise intensity on GE. The effect of work capacity was evaluated by correlating GE with peak power output (PPO). In different subjects (n=9), GE was measured at 50% PPO with and without a prior maximal incremental test. GE was similar in 3- and 6-min stages (19.7 ± 2.8% and 19.3 ± 2.0%), but significantly higher during 1-min stages (21.1 ± 2.7%), GE increased with relative exercise intensity, up to 50% PPO or the power output corresponding to the ventilatory threshold and then remained stable. No relationship between work capacity and GE was found. Prior maximal exercise had a small effect on GE measures; GE was lower after maximal exercise. In conclusion, GE can be determined robustly so long as steady state exercise is performed and RER ≤ 1.0.

Exercise training and cytokines in breast cancer survivors

The purpose of this randomized controlled trial was to determine the effects of an 8-week (aerobic+strength) exercise training program (3 sessions/week) on the circulating cytokine levels of breast cancer survivors. We randomly allocated 16 female survivors of breast cancer (mean±SD age: 50±5 years) to an intervention or usual care (control) group (N=8 in each group). The intervention group followed an 8-week exercise program consisting of 3 sessions/week (session duration: 90 min). We measured the levels of the following cytokines before and after the intervention: beta-NGF, CTACK, eotaxin, FGF basic, G-CSF, gmCSFα, HGF, ICAM1, IFNα2, IFNγ, IL1α, IL1ß, IL1ra, IL2, IL2ra, IL3, IL4, IL6, IL7, IL8, IL9, IL10, IL12, IL13, IL15, IL16, IL17, IL18, IP10, LIF, MCS-F, MIP1α, MIP1β, MIF, MCP1, MCP3, MIG, PDGF bb, SCF, SCGFβ, SDF1α, TRAIL, TNFα, TNFβ, VCAM1, and VEGF. We only observed a significant interaction (group*time) effect for CTACK ( P=0.016), with mean values remaining stable in the intervention group but increasing over time in controls. The intervention program did not induce a significant decrease in the main breast cancer-related cytokines such as IL6 and IL8. A combined (aerobic+strength) 8-week exercise training intervention did not induce major changes in the basal cytokine levels of breast cancer survivors.

GNB3 C825T Polymorphism and elite athletic status: A replication study with two ethnic groups

We aimed to replicate the original findings by Eynon et al. showing an association between the T allele of the GNB3 C825T polymorphism and elite endurance athletic status, in larger cohorts and in other ethnicities. We compared allelic and genotypic frequencies of the GNB3 C825T polymorphism among non-athletic controls (N=340), elite endurance athletes (N=174), and power athletes (N=134). The population sample included participants from 2 different ethnic/geographic backgrounds (Israel and Spain). We observed no significant differences in genotypic and allelic frequencies between countries or groups (all P>0.1). The odds ratio (OR) of being an endurance athlete if the subject had a T allele was 0.841 (95%CI: 0.638-1.110) compared to the control group and 1.047 (95% CI: 0.751-1.461) compared to the power group. Our findings support the need to corroborate genotype:phenotype associations in the field of sports genetics with the largest possible population samples, including populations of different ethnic backgrounds.

The two-hour marathon: who and when?

Whoever breaks 2 h will likely have outstanding running economy and small body size along with exposure to high altitude and significant physical activity early in life. However, neither of these factors nor any specific suite of genotypes appear to be obligatory for a time this fast. Current trends suggest that an East African will be the first to break 2 h. However periods of regional dominance in distance running are not unique to the East Africans: athletes from Finland, Eastern Europe, Australia, and New Zealand have all had extended periods of success at a range of distances. From a physiological perspective, more information is clearly needed on the relationship between VO(2max) and running economy and the influence of running economy and body size on thermoregulation and fuel use.

Exercise in adult and pediatric hematological cancer survivors: an intervention review

Observational research has shown that the physical activity levels of survivors of hematological cancer are low, with deleterious health consequences. This review summarizes the research on exercise interventions in adult and pediatric hematological cancer survivors. We searched MEDLINE, SPORTDiscus, CINAHL, Embase, Cochrane and PEDro through September 2009 for exercise intervention studies in children and adults with any type of hematological cancer. In the 24 adult intervention studies reviewed, we found strong evidence (that is, > or =3 high-quality studies and > or =75% reporting a significant benefit) for a benefit on body composition. Weak, but promising, evidence (> or =3 high-quality studies, but <75% reporting a significant benefit) was found for cardiorespiratory fitness, fatigue, muscle strength, physical functioning and quality of life. In pediatric interventions (13 studies), we found strong evidence for a benefit on muscle strength and cardiorespiratory fitness, particularly, if training was conducted in the hospital setting. Evidence is weak for ankle dorsiflexion, physical functioning and body composition. No exercise-related risks were identified in adults or children studies. Though more randomized controlled trials are needed, a growing body of literature supports the notion that regular physical activity is safe and has potential benefits for both adult and pediatric hematological cancer survivors.

Can we predict top-level sports performance in power vs endurance events? A genetic approach

The goal of our study was to discriminate potential genetic differences between humans who are in both endpoints of the sports performance continuum (i.e. world-class endurance vs power athletes). We used DNA-microarray technology that included 36 genetic variants (within 20 different genes) to compare the genetic profile obtained in two cohorts of world-class endurance (N=100) and power male athletes (N=53) of the same ethnic origin. Stepwise multivariate logistic regression showed that the rs1800795 (IL6-174 G/C), rs1208 (NAT2 K268R) and rs2070744 (NOS3-786 T/C) polymorphisms significantly predicted sport performance (model χ(2) =25.3, df=3, P-value <0.001). Receiver-operating characteristic (ROC) curve analysis showed a significant discriminating accuracy of the model, with an area under the ROC curve of 0.72 (95% confidence interval: 0.66-0.81). The contribution of the studied genetic factors to sports performance was 21.4%. In summary, although an individual's potential for excelling in endurance or power sports can be partly predicted based on specific genetic variants (many of which remain to be identified), the contribution of complex gene-gene interactions, environmental factors and epigenetic mechanisms are also important contributors to the "complex trait" of being an athletic champion. Such trait is likely not reducible to defined genetic polymorphisms.

ACE and ACTN3 genes and muscle phenotypes in nonagenarians

We studied the association of ACE and ACTN3 polymorphisms with skeletal muscle phenotypes (i. e. upper and lower body muscular strength and functional tests) in Spanish nonagenarian subjects [n=41, 33 women, 8 men, age: 90-97 years]. Mean values of the study phenotypes were not significantly different (all P>0.05) between ACE and ACTN3 genotypes. The analyses of the combined effects between genotypes ( ACE DD & ACTN3 RR/RX vs. ACE II/ID & ACTN3 XX) did not yield any significant difference. Our data suggest that, in the elderly, the influence of genetic factors on muscle phenotype traits is not reducible to a few single polymorphisms, including ACE and ACTN3 variants.

Resistance exercise training during pregnancy and newborn's birth size: a randomised controlled trial

OBJECTIVE

We examined the effect of light intensity resistance exercise training performed during the second and third trimester of pregnancy on the newborn's birth size. We also studied the association between maternal body weight prior to pregnancy and newborn's birth size.

DESIGN

Randomised controlled trial.

SUBJECTS

We randomly assigned 160 sedentary gravidae to either a training (n=80) or a control (n=80) group. The training programme focused on light resistance and toning exercises (three times per week, 35-40 min per session). We recorded the Apgar score, birth weight, birth length, and head circumference of the newborn, as well as gestational age at time of delivery from hospital perinatal records. We also measured maternal weight and height before parity and gestational weight gain.

RESULTS

Maternal characteristics neither differed between groups (all P>0.1) nor newborn characteristics (all P>0.1). Maternal body weight was positively and significantly associated with newborn's birth weight and length only in the control group (beta=19.20 and 0.065, respectively, P<0.01).

CONCLUSION

Light intensity resistance training performed over the second and third trimester of pregnancy does not have a negative impact on the newborn's body size or overall health. Exercise interventions might attenuate the adverse consequences of maternal body weight before pregnancy on the newborn's birth size.

Genotype distributions in top-level soccer players: a role for ACE?

We determined the genotype and allelic frequency of several genetic polymorphisms (ACE I/D, GDF-8K153R [and also E164K, P198A and I225T] and AMPD1 C34T) that are candidates to influence sports performance in a group of 54 male professional soccer players. Their results were compared with those of elite endurance male athletes (52 runners) and 123 sedentary, healthy men (controls). We found statistical significance for the ACE ID (chi (2)((2))=8.176, P=0.017) and II genotypes (chi(2)((2))=16.137, P<0.001) with a higher and lower frequency of ID ( P=0.005) and II (P<0.001), respectively, in soccer players than in endurance runners. Statistical significance was also reached for AMPD1 (with a higher frequency of the CT genotype in soccer players than in runners [chi(2)((2))=7.538, P=0.006]) but not for GDF-8 K153R. Since the ACE II genotype is associated with improved potential for endurance performance but with decreased training gains in muscle mass and strength, these findings together with previous results support the notion that elite soccer players tend to have a power/strength oriented genotype.