1.
Two strategies for response to 14 °C cold-water immersion: is there a difference in the response of motor, cognitive, immune and stress markers?
Brazaitis, M, Eimantas, N, Daniuseviciute, L, Mickeviciene, D, Steponaviciute, R, Skurvydas, A
PloS one. 2014;(9):e109020
Abstract
Here, we address the question of why some people have a greater chance of surviving and/or better resistance to cold-related-injuries in prolonged exposure to acute cold environments than do others, despite similar physical characteristics. The main aim of this study was to compare physiological and psychological reactions between people who exhibited fast cooling (FC; n = 20) or slow cooling (SC; n = 20) responses to cold water immersion. Individuals in whom the T(re) decreased to a set point of 35.5 °C before the end of the 170-min cooling time were indicated as the FC group; individuals in whom the T(re) did not decrease to the set point of 35.5 °C before the end of the 170-min cooling time were classified as the SC group. Cold stress was induced using intermittent immersion in bath water at 14 °C. Motor (spinal and supraspinal reflexes, voluntary and electrically induced skeletal muscle contraction force) and cognitive (executive function, short term memory, short term spatial recognition) performance, immune variables (neutrophils, leucocytes, lymphocytes, monocytes, IL-6, TNF-α), markers of hypothalamic-pituitary-adrenal axis activity (cortisol, corticosterone) and autonomic nervous system activity (epinephrine, norepinephrine) were monitored. The data obtained in this study suggest that the response of the FC group to cooling vs the SC group response was more likely an insulative-hypothermic response and that the SC vs the FC group displayed a metabolic-insulative response. The observations that an exposure time to 14 °C cold water--which was nearly twice as short (96-min vs 170-min) with a greater rectal temperature decrease (35.5 °C vs 36.2 °C) in the FC group compared with the SC group--induces similar responses of motor, cognitive, and blood stress markers were novel. The most important finding is that subjects with a lower cold-strain-index (SC group) showed stimulation of some markers of innate immunity and suppression of markers of specific immunity.
2.
Influence of physical activity and nutrition on obesity-related immune function.
Huang, CJ, Zourdos, MC, Jo, E, Ormsbee, MJ
TheScientificWorldJournal. 2013;:752071
Abstract
Research examining immune function during obesity suggests that excessive adiposity is linked to impaired immune responses leading to pathology. The deleterious effects of obesity on immunity have been associated with the systemic proinflammatory profile generated by the secretory molecules derived from adipose cells. These include inflammatory peptides, such as TNF- α , CRP, and IL-6. Consequently, obesity is now characterized as a state of chronic low-grade systemic inflammation, a condition considerably linked to the development of comorbidity. Given the critical role of adipose tissue in the inflammatory process, especially in obese individuals, it becomes an important clinical objective to identify lifestyle factors that may affect the obesity-immune system relationship. For instance, stress, physical activity, and nutrition have each shown to be a significant lifestyle factor influencing the inflammatory profile associated with the state of obesity. Therefore, the purpose of this review is to comprehensively evaluate the impact of lifestyle factors, in particular psychological stress, physical activity, and nutrition, on obesity-related immune function with specific focus on inflammation.
3.
Beyond fast food and slow motion: weighty contributors to the obesity epidemic.
Cizza, G, Rother, KI
Journal of endocrinological investigation. 2012;(2):236-42
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Abstract
Decreased physical activity and marketing-driven increased consumption of "junk" food, dubbed "The Big Two", are generally regarded as the most important contributors to the obesity epidemic. However, the full picture contains many more pieces of the puzzle. We address several additional issues and review current clinical developments in obesity research. In spite of dramatic advancements in our understanding of the adipose organ and its endocrine and immune products, the ultimate causes of the obesity epidemic remain elusive. Treatment is plagued by poor adherence to life style modifications, and available pharmacological options are marginally effective, often also associated with major side effects. Surgical treatments, albeit effective in decreasing body weight, are invasive and expensive. Thus, our approaches to finding the causes, improving the existing treatments, and inventing novel therapies must be manifold.