Trends in Diet and Cancer Research: A Bibliometric and Visualization Analysis.

Diet plays a critical role for patients across the cancer continuum. The World Cancer Research Fund International and the American Cancer Society have published evidence supporting the role of nutrition in cancer prevention. We conducted an analysis of the literature on dietary nutrients and cancer to uncover opportunities for future research. The objective of the bibliometric analysis was to describe trends in peer-reviewed publications on dietary components and cancer and to highlight research gaps. PubMed was queried for manuscripts with diet- and cancer-related keywords and Medical Subject Headings (MeSH) terms. Metadata covering 99,784 publications from 6469 journals were analyzed to identify trends since 1970 on diet topics across 19 tumor types. Publications focused largely on breast, colorectal, and liver cancer, with fewer papers linking diet with other cancers such as brain, gallbladder, or ovarian. With respect to "unhealthy" diets, many publications focused on high-fat diets and alcohol consumption. The largest numbers of publications related to "healthy" diets examined the Mediterranean diet and the consumption of fruits and vegetables. These findings highlight the need for additional research focused on under-investigated cancers and dietary components, as well as dietary studies during cancer therapy and post-therapy, which may help to prolong survivorship.

Skeletal muscle omics signatures in cancer cachexia: perspectives and opportunities.

Cachexia is a life-threatening complication of cancer that occurs in up to 80% of patients with advanced cancer. Cachexia reflects the systemic consequences of cancer and prominently features unintended weight loss and skeletal muscle wasting. Cachexia impairs cancer treatment tolerance, lowers quality of life, and contributes to cancer-related mortality. Effective treatments for cancer cachexia are lacking despite decades of research. High-throughput omics technologies are increasingly implemented in many fields including cancer cachexia to stimulate discovery of disease biology and inform therapy choice. In this paper, we present selected applications of omics technologies as tools to study skeletal muscle alterations in cancer cachexia. We discuss how comprehensive, omics-derived molecular profiles were used to discern muscle loss in cancer cachexia compared with other muscle-wasting conditions, to distinguish cancer cachexia from treatment-related muscle alterations, and to reveal severity-specific mechanisms during the progression of cancer cachexia from early toward severe disease.

Preventable operating room delays in robotic-assisted thoracic surgery: Identifying opportunities for cost reduction.

BACKGROUND: This study aimed to characterize the types of intraoperative delays during robotic-assisted thoracic surgery, operating room staff awareness/perceptions of delays, and cost impact of delays on overall operative costs. METHODS: Robotic-assisted thoracic surgery cases from May to August 2019 were attended by 3 third-party observers to record intraoperative delays. The postoperative surveys were given to operating room staff to elicit perceived delays. Observed versus perceived delays were compared using the McNemar test. Direct costs and charges per delay were calculated. RESULTS: Forty-four cases were observed, of which a majority were lobectomies (n = 38 [86%]). A total of 71 delays were recorded by observers, encompassing 75% of cases (n = 33), with an average delay length of 3.6 minutes (±5.3 minutes). The following delays were observed: equipment failure (n = 40, average delay length 5.0 minutes (±6.5 minutes), equipment missing (n = 15, 2.2 minutes [±1.4 minutes]), staff unfamiliarity with equipment (n = 4, 3.4 minutes [± 1.5 minutes]), and other (n = 12, 4.5 minutes [±5.3 minutes]). The detection rates for any intraoperative delay were consistently lower for all of the operating room team members compared with observers, including surgeons (34.3% vs 77.1%; P = .0003), first assistants (41.9% vs 74.2%; P = .0075), surgical technologists (39.4% vs 72.7%; P = .0045), and circulating nurses (41.18% vs 76.47% minutes; P = .0013). The average operating room variable direct cost of delays based on the average total delay length per case was $225.52 (±$350.18) and was 1.6% (range 0-10.6%) of the total case charges. CONCLUSION: The lack of perception of intraoperative delays hinders operating teams from effectively closing the variable cost gaps. Future studies are needed to explore methods of increasing perception of delays and opportunities to improve operating room efficiency.

Using a Network Physiology Approach to Prescribe Exercise for Exercise Oncology.

Current American College of Sports Medicine (ACSM) exercise guidelines for exercise oncology survivors are generic one-size fits all recommendations, which assume ideal or prototypic health and fitness state in order to prescribe. Individualization is based on the objective evaluation of the patient's baseline physiological status based on a linear dose response relationship of endpoints. This is only a partial snapshot of both the acute and chronic responses exercise can provide. Each acute exercise session represents a unique challenge to whole-body homeostasis and complex acute and adaptive responses occur at the cellular and systemic levels. Additionally, external factors must be considered when prescribing exercise. Network physiology views the human organism in terms of physiological and organ systems, each with structural organization and functional complexity. This organizational approach leads to complex, transient, fluctuating and nonlinear output dynamics which should be utilized in exercise prescription across health states. Targeting health outcomes requires a multi-system approach as change doesn't happen in only one system at a time or in one direction Utilizing a multi-system or person-centered approach, allows for targeting and personalization and understands and targets non-linear dynamics of change. Therefore, the aims of this review are to propose a paradigm shift towards a Network Physiology approach for exercise prescription for cancer survivors. Cancer treatment affects multiple systems that interact to create symptoms and disruptions across these and therefore, prescribing exercise utilizing both external daily factors and internal physiological networks is of the highest order.

Implementation of a Postoperative Screening and Treatment Guidance for the Low Anterior Resection Syndrome: Preliminary Results.

BACKGROUND: Even years after a low anterior resection, many patients experience persisting bowel complaints. This is referred to as low anterior resection syndrome and has a severe adverse effect on quality of life. Its diverse nature makes it difficult to find a gold-standard therapy for this syndrome. However, most importantly, postoperative guidance appears to be suboptimal. OBJECTIVE: The purpose of this study was to describe and evaluate the implementation of a multimodel guidance with structured screening and treatment options. DESIGN: A retrospective, comparative, cross-sectional study was conducted. Data of patients treated before protocol implementation were compared with a cohort after implementation. SETTINGS: This was a single-center study. PATIENTS: Patients seen after low anterior resection or sigmoid resection between 2010 and 2017 for colorectal malignancy were included. INTERVENTION: This included implementation of a postoperative guidance protocol. MAIN OUTCOME MEASURES: Bowel dysfunction was assessed by the low anterior resection score, whereas the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaires (C30 and CR29) assessed general and colorectal-specific quality of life. RESULTS: A total of 243 patients were included; 195 were guided before and 48 after protocol implementation. Patients who underwent low anterior resection after protocol implementation showed significantly lower median low anterior resection scores (31 vs 18; p = 0.02) and less major low anterior resection syndrome (51.9% vs 26.3%; p = 0.045). Patients who underwent sigmoid resection did not present with similar changes. Multiple quality-of-life domains showed clinically significant positive changes since our postoperative protocol was implemented. LIMITATIONS: Patient characteristics are not comparable between groups, which makes it difficult to draw firm conclusions. CONCLUSIONS: We recommend that others reconsider their current postoperative management for patients with rectal cancer and suggest a change to a comparable noninvasive, patient-driven postoperative guidance to enhance patient coping mechanisms and self-management and therefore improve their quality of life. See Video Abstract at http://links.lww.com/DCR/A970. IMPLEMENTACIÓN DE UNA GUÍA POSTOPERATORIA DE DETECCIÓN Y TRATAMIENTO PARA EL SÍNDROME DE RESECCIÓN ANTERIOR BAJA: RESULTADOS PRELIMINARES: Incluso años después de una resección anterior baja, muchos pacientes experimentan quejas intestinales persistentes. Esto se conoce como síndrome de resección anterior baja y tiene un efecto adverso grave en la calidad de vida. Su naturaleza diversa hace que sea difícil encontrar una terapia patrón de oro para este síndrome. Pero lo más importante, la guía postoperatoria parece ser subóptima. OBJETIVO: Describir y evaluar la implementación de una guía de múltiples modelos con opciones estructuradas de selección y tratamiento. DISENO: Se realizó un estudio retrospectivo de corte transversal comparativo. Los datos de los pacientes tratados antes de la implementación del protocolo se compararon con una cohorte después de la implementación. MARCO: Centro de estudio único. PACIENTES: Pacientes después de resección anterior baja o resección sigmoidea entre 2010-2017 por neoplasia colorectal. INTERVENCIÓN:: La implementación de un protocolo de guía postoperatoria. PRINCIPALES MEDIDAS DE RESULTADO: La disfunción intestinal se evaluó mediante la puntuación de resección anterior baja, mientras que la Organización Europea para la Investigación y Tratamiento de Cuestionarios de Calidad de Vida del Cáncer (C30 y CR29) evaluó la calidad de vida general y específicamente colorectal. RESULTADOS: Se incluyeron 243 pacientes, 195 fueron guiados antes y 48 después de la implementación del protocolo. Los pacientes que se sometieron a una resección anterior baja después de la implementación del protocolo mostraron puntuaciones de resección anterior bajas medias significativamente más bajas (31 frente a 18; p = 0,02) y menos puntuaciones de síndrome de resección anterior baja (51,9% frente a 26,3%; p = 0,045). Los pacientes sometidos a resección sigmoidea no presentaron cambios similares. Los múltiples dominios de calidad de vida mostraron cambios positivos clínicamente significativos desde que se implementó nuestro protocolo postoperatorio. LIMITACIONES: Las características de los pacientes no son comparables entre los grupos, lo que dificulta sacar conclusiones firmes. CONCLUSIÓNES:: Recomendamos a otros que reconsideren su manejo postoperatorio actual para pacientes con cáncer de recto y sugerimos un cambio a una guía postoperatoria impulsada por el paciente no invasiva comparable para mejorar los mecanismos de afrontamiento y el autocontrol de los pacientes y, por lo tanto, mejorar su calidad de vida. Vea el Video del Resumen en http://links.lww.com/DCR/A970.

Prehabilitation before major intra-abdominal cancer surgery: A systematic review of randomised controlled trials.

BACKGROUND: Although prehabilitation programmes for patients undergoing major intra-abdominal cancer surgery have been shown to improve pre-operative physical fitness, the conclusions regarding any postoperative benefits are inconsistent. OBJECTIVES: The aim of this study was to evaluate the content of and the outcome measures used in studies of prehabilitation programmes for these patients. It was hypothesised that the content of prehabilitation programmes is often therapeutically invalid, and that the postoperative outcomes assessed are inadequate to evaluate the impact of complications. DESIGN: A systematic review of randomised controlled trials. DATA SOURCES: Studies published between January 2009 and January 2019 were retrieved from PubMed, Embase and PEDro. ELIGIBILITY CRITERIA: Studies were included when they investigated the effects of prehabilitation in patients undergoing intra-abdominal surgery for cancer, reported pre-operative and/or postoperative outcome measures and were conducted as a randomised controlled trial. Studies for which the full text was not available were excluded, as were studies of patients undergoing nonabdominal cancer surgery. RESULTS: Eight studies (565 patients) were included. Therapeutic validity was low in five studies. Most studies included low-risk surgical patients and considerable variation was observed between prehabilitation programmes in terms of supervision, training context, frequency, intensity, duration and training type. Objective monitoring of training progression was typically not performed, and most trials did not include nutritional or psychological support. Postoperative complications were reported in seven studies, but no study reported the impact of postoperative complications, nor on long-term postoperative outcomes. CONCLUSION: The content of prehabilitation programmes was heterogeneous. Studies with a high therapeutic validity found unequivocal evidence that prehabilitation had beneficial effects on postoperative outcomes. Future research should focus on adequate selection and inclusion of high-risk surgical patients and provide personalised and probably multimodal (partly) supervised prehabilitation, with objective monitoring of progress. Measuring the incidence and impact of postoperative complications may contribute to demonstrating the clinical value of prehabilitation.

Cancer treatment effects on cognition and depression: The moderating role of physical activity.

OBJECTIVES: Breast cancer survivors report significant cognitive impairments post treatment, particularly following chemotherapy. Depression may also occur post treatment and may partially mediate the effects of cancer treatment on cognition. Additionally, physical activity has been shown to mitigate treatment effects on cognition and depression. This study examined the role of depression in mediating the effects of cancer treatment on cognitive function (perceived cognitive impairment, PCI; perceived cognitive ability, PCA) in breast cancer survivors and explored the role of physical activity in moderating these effects. MATERIALS AND METHODS: 317 breast cancer survivors were recruited via Army of Women. Participants were 40-75 years old and had stage 0 (in situ) to IIIc breast cancer and were less than 10 years post treatment. Participants completed a demographic and treatment questionnaire, as well as the International Physical Activity Questionnaire, Functional Assessment of Cancer Therapy-Cognitive Function, and Center for Epidemiologic Studies Depression Scale. RESULTS: Depressive symptoms significantly contributed to cognitive function in all models. Moderate and vigorous levels of physical activity moderated breast cancer treatment effects on depression and cognition. Chemotherapy, tamoxifen, and anastrozole all demonstrated negative effects on cognition. CONCLUSION: The results from this study support the importance of examining mediating factors in the effects of cancer treatment on cognition, particularly depression, following cancer treatment. Effects of treatment on cognition in breast cancer survivors are partially explained by changes in depressive symptoms, although chemotherapy may impact cognition independent of depression. Importantly, physical activity may reduce the risk of depression and cognitive impairment in breast cancer survivors.

Multimodal prehabilitation in colorectal cancer patients to improve functional capacity and reduce postoperative complications: the first international randomized controlled trial for multimodal prehabilitation.

BACKGROUND: Colorectal cancer (CRC) is the second most prevalent type of cancer in the world. Surgery is the only curative option. However, postoperative complications occur in up to 50% of patients and are associated with higher morbidity and mortality rates, lower health related quality of life (HRQoL) and increased expenditure in health care. The number and severity of complications are closely related to preoperative functional capacity, nutritional state, psychological state, and smoking behavior. Traditional approaches have targeted the postoperative period for rehabilitation and lifestyle changes. However, recent evidence shows that the preoperative period might be the optimal moment for intervention. This study will determine the impact of multimodal prehabilitation on patients' functional capacity and postoperative complications. METHODS/DESIGN: This international multicenter, prospective, randomized controlled trial will include 714 patients undergoing colorectal surgery for cancer. Patients will be allocated to the intervention group, which will receive 4 weeks of prehabilitation (group 1, prehab), or the control group, which will receive no prehabilitation (group 2, no prehab). Both groups will receive perioperative care in accordance with the enhanced recovery after surgery (ERAS) guidelines. The primary outcomes for measurement will be functional capacity (as assessed using the six-minute walk test (6MWT)) and postoperative status determined with the Comprehensive Complication Index (CCI). Secondary outcomes will include HRQoL, length of hospital stay (LOS) and a cost-effectiveness analysis. DISCUSSION: Multimodal prehabilitation is expected to enhance patients' functional capacity and to reduce postoperative complications. It may therefore result in increased survival and improved HRQoL. This is the first international multicenter study investigating multimodal prehabilitation for patients undergoing colorectal surgery for cancer. TRIAL REGISTRATION: Trial Registry: NTR5947 - date of registration: 1 August 2016.

Awareness and management of low anterior resection syndrome: A Dutch national survey among colorectal surgeons and specialized nurses.

INTRODUCTION: Substantial progress has been made in the treatment of rectal cancer in the past two decades. Low anterior resection is a cornerstone in current treatment, combined with neo-adjuvant (chemo-) radiation in selected cases. However, side effects such as increased frequency, urgency and incontinence are seen in a majority of patients postoperatively. These symptoms, referred to as low anterior resection syndrome (LARS), have a severe impact on quality of life. Management of LARS is complex, and surgeons seem to underestimate and misinterpret the impact of symptoms associated with LARS. AIM AND METHODS: We investigated the awareness and management of LARS in The Netherlands, conducting a national survey in which colorectal surgeons and colorectal care nurses were asked for their views on this complex syndrome. RESULTS: 242 health-care professionals participated in the survey. Most participants estimate the prevalence of major LARS is 20-40% after low anterior resection (LAR); a severe underestimation of actual prevalence - around 70%. Only 10% of surgeons use LARS screening tools in the preoperative period, and fewer than half of surgeons use LARS scores before or after a LAR. Although most surgeons inform their patients preoperatively about the changes in bowel function that they may experience after rectal cancer treatment, a majority of these surgeons indicate more information and patient counselling would improve the quality of life of their patients. DISCUSSION: Impact and prevalence of LARS is underestimated by their physicians. Uniform clinical guidelines should be developed to guide physicians in adequate management of patients with LARS.

The effect of exercise on body composition and bone mineral density in breast cancer survivors taking aromatase inhibitors.

OBJECTIVE: This study examined the effect of 12 months of aerobic and resistance exercise versus usual care on changes in body composition in postmenopausal breast cancer survivors taking aromatase inhibitors (AIs). METHODS: The Hormones and Physical Exercise study enrolled 121 breast cancer survivors and randomized them to either supervised twice-weekly resistance exercise training and 150 min/wk of aerobic exercise (N = 61) or a usual care (N = 60) group. Dual-energy X-ray absorptiometry scans were conducted at baseline, 6 months, and 12 months to assess changes in body mass index, percent body fat, lean body mass, and bone mineral density. RESULTS: At 12 months, the exercise group relative to the usual care group had a significant increase in lean body mass (0.32 vs. -0.88 kg, P = 0.03), a decrease in percent body fat (-1.4% vs. 0.48%, P = 0.03), and a decrease in body mass index (-0.73 vs. 0.17 kg/m2 , P = 0.03). Change in bone mineral density was not significantly different between groups at 12 months (0.001 vs. -0.006 g/cm2 , P = 0.37). CONCLUSIONS: A combined resistance and aerobic exercise intervention improved body composition in breast cancer survivors taking AIs. Exercise interventions may help to mitigate the negative side effects of AIs and improve health outcomes in breast cancer survivors.

Effect of exercise on metabolic syndrome variables in breast cancer survivors.

Objective. Breast cancer survivors are highly sedentary, overweight, or obese, which puts them at increased risk for comorbid chronic disease. We examined the prevalence of, and changes in, metabolic syndrome following 6 months of an aerobic exercise versus usual care intervention in a sample of sedentary postmenopausal breast cancer survivors. Design and Methods. 65 participants were randomized to an aerobic exercise intervention (EX) (n = 35) mean BMI 30.8 (±5.9) kg/m(2) or usual care (UC) (n = 30) mean BMI 29.4 (±7.4) kg/m(2). Metabolic syndrome prevalence was determined, as well as change in criteria and overall metabolic syndrome. Results. At baseline, 55.4% of total women met the criteria for metabolic syndrome. There was no statistically significant change in metabolic syndrome when comparing EX and UC. However, adhering to the exercise intervention (at least 120 mins/week of exercise) resulted in a significant (P = .009) decrease in metabolic syndrome z-score from baseline to 6 months (-0.76 ± 0.36) when compared to those who did not adhere (0.80 ± 0.42). Conclusions. Due to a higher prevalence of metabolic syndrome in breast cancer survivors, lifestyle interventions are needed to prevent chronic diseases associated with obesity. Increasing exercise adherence is a necessary target for further research in obese breast cancer survivors.

Obesity, growth hormone and exercise.

Growth hormone (GH) is regulated, suppressed and stimulated by numerous physiological stimuli. However, it is believed that obesity disrupts the physiological and pathological factors that regulate, suppress or stimulate GH release. Pulsatile GH has been potently stimulated in healthy subjects by both aerobic and resistance exercise of the right intensity and duration. GH modulates fuel metabolism, reduces total fat mass and abdominal fat mass, and could be a potent stimulus of lipolysis when administered to obese individuals exogenously. Only pulsatile GH has been shown to augment adipose tissue lipolysis and, therefore, increasing pulsatile GH response may be a therapeutic target. This review discusses the factors that cause secretion of GH, how obesity may alter GH secretion and how both aerobic and resistance exercise stimulates GH, as well as how exercise of a specific intensity may be used as a stimulus for GH release in individuals who are obese. Only five prior studies have investigated exercise as a stimulus of endogenous GH in individuals who are obese. Based on prior literature, resistance exercise may provide a therapeutic target for releasing endogenous GH in individuals who are obese if specific exercise programme variables are utilized. Biological activity of GH indicates that this may be an important precursor to beneficial changes in body fat and lean tissue mass in obese individuals. However, additional research is needed including what molecular GH variants are acutely released and involved at target tissues as a result of different exercise stimuli and what specific exercise programme variables may serve to stimulate GH in individuals who are obese.

Effects of acute resistance exercise on muscle damage and perceptual measures between men who are lean and obese.

The purpose of this investigation was to assess indices of muscle damage and psychological stress between young, untrained, lean, and obese men. Using a between-subject design, 19 young men (9 lean men [age, 20.1 ± 2.1 years; body mass, 71.7 ± 5.8 kg; height, 177.8 ± 8.7 cm; body fat (BF), 14.7 ± 3.5%], 5 World Health Organization [WHO] class 1 obese men [age, 21.6 ± 2.5 years; body mass, 97.8 ± 8.6 kg; height, 176.3 ± 3.7 cm; BF, 34.7 ± 3.0%], and 5 WHO class 2 or 3 men [age, 20.0 ± 1.4 years; body mass, 120.8 ± 10.5 kg; height, 177.7 ± 5.2 cm; BF, 40.5 ± 5.8%]) volunteered and completed an acute resistance exercise (RE) protocol (6 exercises performed for 3 sets of 10 repetitions at an intensity of 85-95% of a 10 repetition maximum). Plasma myoglobin and serum creatine kinase were obtained before and immediately after exercise, and in recovery (at +110 minutes and +24 hours). Perceptual measures including rating of perceived exertion, pain and soreness, fatigue, and general soreness were assessed at different time points (during exercise for rating of perceived exertion, and for the fatigue and soreness measures before, immediately after, and at 24 hours of recovery from exercise). The primary findings of this investigation were that lean and obese, sedentary, young men do not significantly differ from each other in terms of indirect, humoral measures of muscle damage, or perceptual scales in response to a moderate-intensity acute RE bout, despite using significantly more exercise volume relative to fat mass (FM). We conclude that excess FM during daily activities of life provides a protective effect for muscle damage. When strength training individuals who are obese, practitioners should be aware of how excess FM affects muscle damage and total volume. But these considerations do not preclude individuals who are obese from using well-designed RE workouts which use free-weight, multijoint movements that stimulate all of the major muscle groups.

Effect of exercise on markers of inflammation in breast cancer survivors: the Yale exercise and survivorship study.

Physical activity is associated with improved breast cancer survival, but the underlying mechanisms, possibly including modification of the inflammatory state, are not well understood. We analyzed changes in interleukin (IL)-6, C-reactive protein (CRP), and TNF-α in a randomized controlled trial of exercise in postmenopausal breast cancer survivors. Seventy-five women, recruited through the Yale-New Haven Hospital Tumor Registry, were randomized to either a six-month aerobic exercise intervention or usual care. Correlations were calculated between baseline cytokines, adiposity, and physical activity measures. Generalized linear models were used to assess the effect of exercise on IL-6, CRP, and TNF-α. At baseline, IL-6 and CRP were positively correlated with body fat and body mass index (BMI) and were inversely correlated with daily pedometer steps (P < 0.001). We found no significant effect of exercise on changes in inflammatory marker concentrations between women randomized to exercise versus usual care, though secondary analyses revealed a significant reduction in IL-6 among exercisers who reached 80% of the intervention goal compared with those who did not. Future studies should examine the effect of different types and doses of exercise and weight loss on inflammatory markers in large-scale trials of women diagnosed with breast cancer.

Weight Loss Intervention for Breast Cancer Survivors: A Systematic Review.

To determine the effectiveness of weight loss intervention for breast cancer survivors. From October 2012 until March 2013, Pubmed was searched for weight loss intervention trials that reported body weight or weight loss as a primary outcome. Fifteen of these studies are included in this review. Of the 15 studies included, 14 resulted in statistically significant weight loss and 10 obtained clinically meaningful weight loss of ≥5 % from baseline. Evidence was provided of the feasibility of using several methods of weight loss intervention (telephone, in person, individual, group). Successful intervention used a comprehensive approach, with dietary, physical activity, and behavior modification components. Weight loss improved cardiovascular risk factors and markers of glucose homeostasis. However, there is insufficient evidence to identify the components of this intervention that led to successful weight loss, or to determine the weight loss necessary to affect biomarkers linked to breast cancer prognosis. The small number of randomized controlled trials shared several limitations, including small study sample sizes and lack of follow-up beyond 6 months. Intervention with longer follow-up revealed weight regain, showing the importance of considering strategies to promote long-term weight maintenance. Weight loss intervention for breast cancer survivors can lead to statistically significant and clinically meaningful weight loss, but the limited number of interventional studies, small sample sizes, and short duration of follow-up in many studies limit our ability to draw conclusions regarding the most efficacious weight-loss intervention after a breast cancer diagnosis. The findings to date are encouraging, but research on the effect of weight loss on breast cancer recurrence and mortality, and on prevention of weight gain for women newly diagnosed with breast cancer, is needed.

Effects of resistance exercise and obesity level on ghrelin and cortisol in men.

Resistance exercise (RE) is increasingly recommended by health organizations as a weight management tool. The purpose of this study was to examine the effects of an acute high-volume, whole-body RE protocol on the glucoregulatory and ghrelin response in sedentary obese and lean men. Five World Health Organization (WHO) class 1 obese (body mass index [BMI], 30.00-34.99) (age, 21.6 ± 2.5 years; height, 176.3 ± 3.7 cm; body mass, 97.8 ± 8.58 kg; body fat, 34.7% ± 2.95%), 5 WHO 2 (BMI, 35-39.99)/WHO 3 (BMI, ≥40) obese (age, 20.0 ± 1.4 years; height, 177.7 ± 5.15 cm; body mass, 120.8 ± 10.49 kg; body fat, 40.5% ± 5.82 %), and 9 lean men (age, 20.1 ± 2.1 years; height, 177.8 ± 8.7 cm; body mass, 71.7 ± 5.8 kg; body fat, 14.7% ± 3.54 %) completed an acute RE testing protocol (6 exercises, 3 sets of 10 repetitions at 85%-95% 10-repetition maximum with 120- and 90-second rest periods); and blood samples were collected pre-, mid-, and immediately postexercise and during recovery (+50, +70, and +110). Resistance exercise produced differences over time in cortisol, insulin, and glucose. Group differences were observed for ghrelin, with the WHO class 2/3 group having significantly greater ghrelin levels than the lean group (d = 0.28, P = .009) and the WHO class 1 group (d = 0.39, P = .002). Higher ghrelin was significantly associated with lower cortisol only in obese individuals. In addition, higher growth hormone was associated with lower ghrelin in lean individuals. Results suggest that glucoregulatory homeostasis is altered with increasing levels of obesity and that these alterations may mediate the response of cortisol and ghrelin in response to RE.

Immunoreactive and bioactive growth hormone responses to resistance exercise in men who are lean or obese.

It has been suggested that obese individuals have a blunted growth hormone (GH) response to spontaneous and stimulated GH secretion. The present study was designed to examine the effects of a high-volume, whole body acute resistance exercise (RE) protocol on immunoreactive GH (iGH), bioactive GH (bGH), and GH-binding protein (GHBP) in sedentary lean and obese men. Nine obese (mean ± SD: 20.8 ± 2.1 yr old, 177.0 ± 4.1 cm height, 108.7 ± 15.9 kg body mass, 37.6 ± 5.29% body fat) and nine lean (20.1 ± 2.1 yr old, 177.8 ± 8.7 cm height, 71.7 ± 5.8 kg body mass, 14.7 ± 3.54% body fat) men completed an acute RE protocol (6 exercises, 3 sets of 10 repetitions at 85-95% of 10 repetitions maximum with 120- and 90-s rest periods), and blood samples were collected before, at the midpoint, and immediately after exercise and during recovery (+50, +70, and +110). In contrast to prior studies, which examined acute responses to cardiovascular exercise protocols, groups did not differ in iGH response to the exercise stimulus. However, bGH concentrations overall were significantly lower in the obese than the lean participants (P < 0.001). Additionally, obese individuals had significantly higher GHBP concentrations (P < 0.001). Results suggest that obese and lean sedentary men performing a high-volume, whole body acute RE protocol demonstrate similar increases in iGH. Blunted bGH and elevated GHBP concentrations are indicative of altered GH activity associated with obesity. Prior research findings of blunted iGH response may be attributable to RE protocols not equated on relative intensity or volume. These results underscore the complexity of pituitary biology and its related mechanisms and may have implications for exercise prescription in the treatment of obesity.

Growth hormone, exercise, and athletic performance: a continued evolution of complexity.

Growth hormone (hGH) presents pleiotropic effects in many tissues encompassing a diverse range of physiological actions. Its complexity as a family of hormones with different isoforms and different somatotroph molecular functions continues to challenge the status quo of our understanding of its release, function, and signaling. Owing to the fact that the majority of the literature has viewed hGH from the perspective of the primary 22 kD monomer, further investigation is needed as to the influence and biological activity of other aggregate and splice variant isoforms that are released into circulation. Its role over the life span and with supplementation yields equivocal results with more study needed. Testing for the use of hGH has progressed, and the first positive test was recently documented. Understanding of pituitary function and physiology will remain complex until the use of a broader range of analytical techniques, including assays, becomes mainstream.

Effects of a whole body compression garment on markers of recovery after a heavy resistance workout in men and women.

The primary purpose of this investigation was to evaluate the influence of a whole body compression garment on recovery from a typical heavy resistance training workout in resistance-trained men and women. Eleven men (mean +/- SD: age, 23.0 +/- 2.9 years) and 9 women (mean +/- SD: age 23.1 +/- 2.2 years) who were highly resistance trained gave informed consent to participate in the study. A within-group (each subject acted as their own control), balanced, and randomized treatment design was used. Nutritional intakes, activity, and behavioral patterns (e.g., no pain medications, ice, or long showers over the 24 hours) were replicated 2 days before each test separated by 72 hours. An 8-exercise whole body heavy resistance exercise protocol using barbells (3 sets of 8-10 repetition maximum, 2.0- to 2.5-minute rest) was performed after which the subject showered and put on a specific whole body compression garment one designed for women and one for men (CG) or just wore his/her normal noncompression clothing (CON). Subjects were then tested after 24 hours. Dependent measures included sleep quality, vitality rating, resting fatigue rating, muscle soreness, muscle swelling via ultrasound, reaction movement times, bench throw power, countermovement vertical jump power, and serum concentrations of creatine kinase (CK) measured from a blood sample obtained via venipuncture of an arm vein. We observed significant (p < or = 0.05) differences between CG and CON conditions in both men and women for vitality (CG > CON), resting fatigue ratings (CG < CON), muscle soreness (CG < CON), ultrasound measure swelling (CG < CON), bench press throw (CG > CON), and CK (CG < CON). A whole body compression garment worn during the 24-hour recovery period after an intense heavy resistance training workout enhances various psychological, physiological, and a few performance markers of recovery compared with noncompressive control garment conditions. The use of compression appears to help in the recovery process after an intense heavy resistance training workout in men and women.

l-Carnitine l-tartrate supplementation favorably affects biochemical markers of recovery from physical exertion in middle-aged men and women.

The purpose of this study was to examine the effects of Carnipure tartrate (Lonza, Allendale, NJ) supplementation (total dose of 2 g/d of l-carnitine) on markers of performance and recovery from physical exertion in middle-aged men and women. Normally active and healthy men (n = 9, 45.4 +/- 5.3 years old) and women (n = 9, 51.9 +/- 5.0 years old) volunteered to participate in the investigation. Double-blind, placebo, balanced treatment presentation and crossover design were used with 3 weeks and 3 days of supplementation followed by a 1-week washout period before the other counterbalanced treatment was initiated. After 3 weeks of each supplementation protocol, each participant then performed an acute resistance exercise challenge of 4 sets of 15 repetitions of squat/leg press at 50% 1-repetition maximum and continued supplementation over the recovery period that was evaluated. Blood samples were obtained at preexercise and at 0, 15, 30, and 120 minutes postexercise during the acute resistance exercise challenge and during 4 recovery days as well. Two grams of l-carnitine supplementation had positive effects and significantly (P < or = .05) attenuated biochemical markers of purine metabolism (ie, hypoxanthine, xanthine oxidase), free radical formation (malondialdehyde), muscle tissue disruption (myoglobin, creatine kinase), and muscle soreness after physical exertion. However, markers of physical performance (ie, strength, power, get up and go) were not affected by supplementation. These findings support our previous findings of l-carnitine in younger people that such supplementation can reduce chemical damage to tissues after exercise and optimize the processes of muscle tissue repair and remodeling.