Physical activity and cancer prevention: a review of current evidence and biological mechanisms

Objective. The main aim of this paper is to review the evidence available from the date of PubMed?s inception to May 2011 for a link between cancer and physical activity (PA) in both animal models and humans. Methods. We decided to select studies that comply with the scheme proposed by the American College of Sports Medicine/ American Heart Association (ACSM/AHA) that distinguish occupational physical activity (OPA) and leisure-time physical activity (LT-PA), further classified in three levels of intensity (low, moderate and heavy) based on the Metabolic Equivalent of Task (MET) index. Results. Considering animal models, there was strong evidence for an inverse association between voluntary wheel exercise and the risk of colon and breast cancer. Regarding human studies, we identified the following main results: 1) colorectum: LT-PA provided an overall colon risk reduction of 13-14%; 2) breast: significant reduction in the frequency of post-menopausal (PMP) cancers in women that practiced heavy and moderate LT-PA; 3) prostate: heavy OPA and LT-PA seemed to reduce the risk of advanced prostate cancers; 4) endometrium: strong protective effect of heavy/moderate LT-PA among overweight/ obese women; 5) lung: inverse relationship between heavy LT-PA and lung cancer in former or current smokers across all histologies. Conclusion. Increased LT-PA is associated with cancer prevention in several organs, but strong biases, such as body mass index (BMI), gender and age, make it difficult to assess which aspects of PA contribute most strongly to the reduced risk. Furthermore, we found few studies that indicated a protective role for OPA in cancer prevention when compared with LT-PA

Endocrine and metabolic evaluation of classic Klinefelter syndrome and high-grade aneuploidies of sexual chromosomes with male phenotype: are they different clinical conditions?

Klinefelter syndrome (KS) is the most common sex chromosome aneuploidy in males. As well as classic KS, less frequent higher-grade aneuploidies (HGAs) are also possible. While KS and HGAs both involve testicular dysgenesis with hypergonadotropic hypogonadism, they differ in many clinical features. The aim of this study was to investigate the endocrinal and metabolic differences between KS and HGAs.Objective: Klinefelter syndrome (KS) is the most common sex chromosome aneuploidy in males. As well as classic KS, less frequent higher-grade aneuploidies (HGAs) are also possible. While KS and HGAs both involve testicular dysgenesis with hypergonadotropic hypogonadism, they differ in many clinical features. The aim of this study was to investigate the endocrinal and metabolic differences between KS and HGAs. Design: Cross-sectional, case-control study. Methods: 88 patients with KS, 24 with an HGA and 60 healthy controls. Given the known age-related differences all subjects were divided by age into subgroups 1, 2 and 3. Pituitary, thyroid, gonadal and adrenal functions were investigated in all subjects. Metabolic aspects were only evaluated in subjects in subgroups 2 and 3. Results: FT4 and FT3 levels were significantly higher in HGA than in KS patients in subgroups 1 and 2; in subgroup 3, FT4 was significantly higher in controls than in patients. Thyroglobulin was significantly higher in HGA patients in subgroup 1 than in KS patients and controls. Hypergonadotropic hypogonadism was confirmed in both KS and HGA patients, but was more precocious in the latter, as demonstrated by the earlier increase in gonadotropins and the decrease in testosterone, DHEA-S and inhibin B. Prolactin was significantly higher in HGA patients, starting from subgroup 2. Total and LDL cholesterol were significantly higher in HGA patients than in KS patients and controls, while HDL cholesterol was higher in controls than in patients. Conclusions: KS and HGAs should be considered as two distinct conditions

Adverse pathophysiological influence of early testosterone therapy on the testes of boys with higher grade sex chromosome aneuploidies (HGAs): a retrospective, cross-sectional study

Purpose: Higher grade aneuploidies (HGAs) of the male sex chromosomes are a rare genetic group of pathologies caused by nondisjunction meiotic events. The aim of this study was to evaluate the impact of early androgenic therapy on the testicular secretory hormone profile, and the pathophysiological implications. Patients and methods: In this cross-sectional study, 18 HGA subjects aged 6–8 years were recruited. They were divided into two groups, based on whether or not they had previously undergone testosterone therapy (group 1: 11 untreated subjects; group 2: 7 treated subjects). Serum FSH, LH, testosterone (T), inhibin B (INHB) and anti-Müllerian hormone (AMH) were determined, and auxological parameters were assessed. Five group 1 patients and four group 2 patients were treated with hCG (human chorionic gonadotropin) for inguinal cryptorchidism; their hormone profile and auxological parameters were assessed both pre- and post-hCG treatment. Results: Group 1 subjects showed significantly higher testicular volume and higher levels of AMH and INHB (p < 0.0001). Subjects who had undergone hCG therapy showed a significantly higher testicular volume, penis length (respectively, p = 0.008 and p = 0.0005 for group 1 and p = 0.04 and p = 0.001 for group 2) and T (p = 0.005 for group 1 and p = 0.004 for group 2). Conclusions: HGA patients undergoing early testosterone therapy show an earlier and persistent suppression of testicular secretory function. At this age, the testes are still responsive to stimulation with hCG. The selection of patients to be treated must be accompanied by a thorough clinical and hormonal evaluation