61 research outputs found
Adiponectin, Leptin and Visfatin in Hypoxia and its Effect for Weight Loss in Obesity
No full textRationale: Hypoxia induces leptin gene expression in human adipocytes via hypoxia-inducible factors (HIF-α/β). Under ambient moderate hypoxia, leptin in adipocytes is elevated for at least 14 days. Leptin is supposedly involved in the reduced food intake, increased utilization of fatty acids for energy production and possible weight loss observed at high altitudes. Literature on adiponectin and visfatin in high altitude is inconsistent with reports of elevated levels and non-elevated levels. Exercise in hypoxia studies in obese subjects have shown a significant weight loss after up to 3 weeks, but it is unclear if this effect holds up for longer time periods. Therefore, we aimed to investigate 32 obese subjects completing 52 exercise and rest sessions within 8 months at either moderate or sham hypoxia and to analyze leptin, adiponectin, and visfatin mRNA-expression at different time points of exposure. Methods: Abdominal subcutaneous fat biopsies were taken from 32 obese subjects before, after 3 months and after 8 months of intervention. Subjects were randomly divided into two groups and exercised at moderate intensity at two different study sites twice a week. The IG was exposed to normobaric hypoxia (FiO2: 14.0 ± 0.2%,) at exercise and at rest (FiO2: 12.0 ± 0.2%) and the CG to sham hypoxia. Quantitative real-time polymerase chain reaction (qPCR) was used in order to determine mRNA-levels of leptin, adiponectin, and visfatin. Results: No differences in leptin levels after 3 and 8 months compared to baseline and between groups were found. There was no significant difference regarding adiponectin or visfatin at any time point compared to baseline in the hypoxia group, but an increase after 3 months was seen in the control group at normoxia compared to the hypoxia group (adiponectin: p = 0.029 and visfatin: p = 0.014). Conclusion: In this first several months' duration randomized sham controlled hypoxia exercise and rest study with obese subjects, we found no time extended leptin mRNA-expression in subjects under hypoxia after 3 and 8 months compared to baseline levels. Moderate exercise in normoxia not in hypoxia leads to elevated adiponectin and visfatin levels after 3 months
Risk Factors Associated with Groin Pain in Athletes: A Systematic Review
No full textGroin pain is a common and multifactorial condition in athletes, leading to performance impairment and a reduction in participation in sports. This systematic review aimed to identify and synthesise risk factors for groin pain in athletes. A comprehensive search of PubMed, Embase, Web of Science, Scopus, and SPORTDiscus was conducted from inception to May 2025. Observational studies were included, and the risk of bias was assessed using the ROBINS-E tool. Due to heterogeneity across studies, a narrative synthesis was performed. Eight retrospective cohort studies comprising 4249 male athletes from various sports met the inclusion criteria. The most consistent risk factors were a previous history of groin injury, reduced eccentric hip adduction strength, limited hip rotation, and inadequate preseason conditioning. Additional contributors included participation in Olympic weightlifting as part of sport-specific conditioning, playing in skill-specific positions, and the presence of subclinical symptoms, with associations ranging from moderate to high. The overall quality of evidence was low to moderate, with confounding and outcome measurement being the most frequent sources of bias. These findings highlight the multifactorial nature of groin pain and underscore the need for individualised screening, early detection, and preventive approaches. Future research should prioritise prospective designs, standardised diagnostic criteria, and inclusion of female athletes to improve clinical applicability
The outlook for the metropolitan area
No full textThe author assesses the region's future and identifies policies that might improve the local outlook. He acknowledges that substantial cuts in the local tax burden could increase growth but doubts whether local governments could afford such widespread reductions. Instead, he argues, it would be more beneficial for authorities to seek ways to lower the cost of doing business in the region, possibly by reducing taxes levied on intermediate goods and services purchased by businesses.New York (N.Y.) ; Federal Reserve District, 2nd
Physiological effects of training in hypoxic environments and its benefits for prevention and rehabilitation
No full textBackground: The benefits of training in hypoxic environments are widely discussed. Several interventional studies prove its usefulness for different applications. Lately the impact of hypoxia on pre-existing health conditions in middle aged and elderly populations has come into focus. Especially the potential of hypoxic training in reducing the workload during endurance training could withhold great benefits for orthopedically impaired populations like geriatric patients. Furthermore, several studies show beneficial effects of hypoxic training on cardiovascular risk factors and blood perfusion in muscles. This study compound aims at the investigation of physiological effects and potential benefits of hypoxic training interventions in the elderly.
Methods: Three studies and one review are supposed to give an overview of physiological effects and the usability of hypoxia as additive for endurance training in the elderly. Study A evaluates the effects of a commonly practiced hiking prevention program on cardiovascular risk factors in 24 elderly subjects (10 female, age 66.2 ± 4.4 years and 14 male, age 65.6 ± 2.7 years). Study B and C identify possible obstacles and risks when planning rehabilitation or prevention programs in NH. Study B shows the main differences between NH and HH comparing the physiological effects in six subjects (age 28.3 ± 8.2 years) during a “real” and a simulated hike. Meanwhile, paper C gives an overview of possible risks and especially the impact of prolonged hypoxia exposure and its potential impact on cognitive functions. Finally, in Study D, 40 geriatric patients (NG: n = 16, age 82.0 ±7.8 years, HG: n = 19, age 80.2 ± 7.2 years) participated in a single blinded, placebo controlled interventional study, investigating the potential reduction of physical workload during endurance training using NH and its physiological effects.
Results: Only one hiking session per week over a time course of nine months does not lower cardiovascular risk factors in subjects older than 60 years. Systolic blood pressure seems to be lowered only in patients with pathological or borderline values. For prevention- or rehabilitation programs, using normobaric hypoxia, some differences have to be taken into account. In NH, heartrate is lower while peripheral oxygen saturation is higher maintaining a similar physical strain as in HH (p < 0.05). Furthermore, NH seems to impair cognitive reaction time after sleep to a certain degree. Physical workload (Watt/kg p = 0.012) and related parameters are significantly reduced in a three week interventional endurance training study on simulated 3000 m in the elderly.
Discussion: NH training lowers physical workload during endurance training in the elderly. Especially for geriatric rehabilitation, where patients and their therapists have only three weeks and rather short training sessions for measurable improvements, NH has great benefits. Furthermore, it seems to provide a safe environment and allows better monitoring than HH for prevention- or rehabilitation programs. Cardiac and pulmonary demands are lower in NH compared to HH. Overnight stays in hypoxia bear some risk for cognitive impairment, which has to be taken into account as possible risk for accidents. Nevertheless, we think during normal daytime training sessions and in quite low altitudes, this is no limiting factor for preventive- or rehabilitative programs. The common hiking routine of only one hiking session per week, practiced by most elderly, seems not to be sufficient to improve cardiovascular fitness. Therefore, the search for new possibilities to use the benefits of hypoxia for this age group is of importance.
Conclusion: Training in hypoxic environments bears a lot of potential for certain patient groups. Especially the use of NH as additive to endurance training either to lower physical workload or to enhance the training intensity seems to be promising. This also could open the field of low volume high intensity training for geriatrics
Impaired Nocturnal Cerebral Hemodynamics during Long Obstructive Apneas: The Key to Understanding Stroke in OSAS Patients?
No full text¿Necesitamos polisomnografías repetidas para cambiar la presión en los pacientes con CPAP?
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Hidden secrets of the upper airway on the track to individualized sleep medicine: highlights from the 2018 ATS Conference in San Diego
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