Hypoxia, energy balance and obesity: from pathophysiological mechanisms to new treatment strategies

Abstract

High altitude exposure is often accompanied by weight loss. Postulated mechanisms are a reduction of nutritional energy intake, a reduction of intestinal energy uptake from impaired intestinal function and increased energy expenditure. Beyond the field of altitude, there are good reasons for renewed interest in the relationship between hypoxia and energy balance. The increasing prevalence of obesity and associated comorbidities represent a major health concern. Obesity is frequently associated with sleep disorders leading to intermittent systemic hypoxia with deleterious cardiovascular and metabolic consequences. Hypoxic regions may be present within hypertrophic white adipose tissue leading to chronic systemic inflammation. Among the increasing number of people commuting to altitude for work or leisure, obesity is a risk factor for acute mountain sickness. Paradoxically, exposure to intermittent hypoxia might be considered as a means to lose body mass and to improve metabolic risk factors. Daytime exposure to intermittent hypoxia has been used to treat hypertension in former Soviet Union countries and is now being experimented elsewhere. Such intermittent hypoxic exposure at rest or during exercise may lead to improvement in body composition and health status with improved exercise tolerance, metabolism and systemic arterial pressure. Future research should confirm whether hypoxic training could be a new treatment strategy for weight loss and comorbidities in obese subjects and elucidate the underlying mechanisms and signalling pathways.

Obesity as a Conditioning Factor for High-Altitude Diseases

“…Despite the fact that some studies suggest that exposure to CIH at moderate altitudes might be considered as a mean to lose body mass and improve metabolic risk factors [48,49,50] or that it has other beneficial effects [51], this condition (long-term CIH at high altitude) is a rather novel biological situation, and, for this reason, it is not fully and comprehensively understood or studied. Additionally, it is currently thought that the CIH model shares both exposure conditions: subjects experience acute exposure during the first days at high altitude and chronic exposure for extended periods of time [11,16].…”

“…A greater degree of alveolar hypoxia at altitude, which is aggravated by obesity, causes a further rise in PAP [47]. In addition, obese patients experience an increased inflammatory state, with the presence of inflammation mediators where increased levels of interleukin 6 have been described, along with other cytokines [48]. The above conditions are at the core of the current understanding of HAPE pathophysiology [44].…”

Application of High-Dimensional Statistics and Network Based Visualization Techniques on Arab Diabetes and Obesity Data

“…For a normally distributed variable in both groups, the Student's t-test was used to determine significance of difference in means between groups. In this case, the F-test was used to compare variance of the or defect in its biogenesis [12], hypoxia [13] and impairment of the host anti-stress defence system [14][15][16][17]. Recent evidence indicated that the uncontrolled inflammatory response and metabolic stress are highly integrated and they likely work in vicious cycles [9,18,19].…”

Influence of Intermittent Normobaric Hypoxia on Cardiovascular System and Hemodynamic Parameters of Children Lived at Radiation Contaminated Territories

“…Зростає активність гіпоталамо-гіпо-фізарно-наднирковозалозної системи [5,22]. Норадреналін і адреналін через систему вну-трішньоклітинних посередників стимулюють секрецію ключового ферменту розщеплення глікогену фосфорілази [8,23]. При тривалому перебуванні в умовах зниження Ро 2 (прове-дення сеансів ПНГ) посилюється еритропоез, збільшується синтез нуклеїнових кислот і білків.…”