The betaine content of sweat from adolescent females

<p>Abstract</p> <p>Background</p> <p>This study was developed to establish whether betaine was present in the sweat of females and to determine any correlations with other sweat components.</p> <p>Methods</p> <p>Sweat patches were placed on eight trained adolescent Highland dancers (age = 13.6 ± 2.3 yr), who then participated in a dance class for 2 hours. Patches were removed, and the sweat recovered via centrifugation. The sweat was subsequently analyzed for betaine, choline, sodium, potassium, chloride, lactate, glucose, urea and ammonia.</p> <p>Results</p> <p>Betaine was present in the sweat of all subjects (232 ± 84 μmol·L^-1), which is higher than typically found in plasma. The concentration of several sweat components were correlated, in particular betaine with most other measured components.</p> <p>Conclusion</p> <p>Betaine, an osmoprotectant and methyl donor, is a component of sweat that may be lost from the body in significant amounts.</p

Obesity, but not hypohydration, mediates changes in mental task load during passive heating in females

Background The independent effects of hypohydration and hyperthermia on cognition and mood is unclear since the two stresses often confound each other. Further, it is unknown if obese individuals have the same impairments during hyperthermia and hypohydration that is often observed in non-obese individuals. Methods The current study was designed to assess the independent and combined effects of mild hypohydration and hyperthermia on cognition, mood, and mental task load in obese and non-obese females. Twenty-one healthy females participated in two passive heating trials, wherein they were either euhydrated or hypohydrated prior to and throughout passive heating. Cognition (ImPACT), mental task load (NASA-TLX), and mood (Brunel Mood Scale; BRUMS) were measured before and after a 1.0 °C increase in core temperature (TC). Results After a 1.0 °C TC elevation, hypohydration resulted in greater (p  0.05). Hyperthermia, regardless of hydration status, impaired (∼5 A.U) measures of memory-based cognition (verbal and visual memory), and increased mental task load, while worsening mood (p  0.05). Conclusion These data indicate that hyperthermia independently impairs memory-based aspects of cognitive performance, mental task load, and leads to a negative mood state. Mild hypohydration did not exacerbate the effects of hyperthermia. However, obese individuals had increased mental task load during hyperthermia

The betaine content of sweat from adolescent females

Abstract Background This study was developed to establish whether betaine was present in the sweat of females and to determine any correlations with other sweat components. Methods Sweat patches were placed on eight trained adolescent Highland dancers (age = 13.6 ± 2.3 yr), who then participated in a dance class for 2 hours. Patches were removed, and the sweat recovered via centrifugation. The sweat was subsequently analyzed for betaine, choline, sodium, potassium, chloride, lactate, glucose, urea and ammonia. Results Betaine was present in the sweat of all subjects (232 ± 84 μmol·L-1), which is higher than typically found in plasma. The concentration of several sweat components were correlated, in particular betaine with most other measured components. Conclusion Betaine, an osmoprotectant and methyl donor, is a component of sweat that may be lost from the body in significant amounts

Expression of specific inflammasome gene modules stratifies older individuals into two extreme clinical and immunological states

Low-grade, chronic inflammation has been associated with many diseases of aging, but the mechanisms responsible for producing this inflammation remain unclear. Inflammasomes can drive chronic inflammation in the context of an infectious disease or cellular stress, and they trigger the maturation of interleukin-1β (IL-1β). Here we find that the expression of specific inflammasome gene modules stratifies older individuals into two extremes: those with constitutive expression of IL-1β, nucleotide metabolism dysfunction, elevated oxidative stress, high rates of hypertension and arterial stiffness; and those without constitutive expression of IL-1β, who lack these characteristics. Adenine and N4-acetylcytidine, nucleotide-derived metabolites that are detectable in the blood of the former group, prime and activate the NLRC4 inflammasome, induce the production of IL-1β, activate platelets and neutrophils and elevate blood pressure in mice. In individuals over 85 years of age, the elevated expression of inflammasome gene modules was associated with all-cause mortality. Thus, targeting inflammasome components may ameliorate chronic inflammation and various other age-associated conditions

Effect of ambient temperature and caffeine on performance, metabolic, cardiovascular, endocrine, hematological, perceptual, and mood measures during endurance exercise

Little is known about the effect of environmental temperature and caffeine on performance, metabolic, cardiovascular, endocrine, hematological, perceptual, and mood measures during endurance exercise. The purpose of these studies was to compare the effects of ambient temperature on caffeine ergogenicity during endurance cycling exercise. Eleven male cyclists (mean ± SD; age, 25 ± 6 y; mass, 72.6 ± 8.1 kg; V&dot;O2max, 58.7 ± 2.9 ml·kg-1·min-1) completed four exercise trials in a randomized, double blind, crossover experimental design. After cycling for 90 min (average 65 ± 7 %V&dot;O2max ) and remaining euhydrated in a warm (33 ± 1°C) or cool (12 ± 1°C) environment, subjects completed a 15-min performance trial (PT; based on total work accumulated). Subjects ingested 3 mg·kg -1 of caffeine (CAF) or placebo (PLA) 60 min prior to and 45 after beginning exercise. Total work (KJ) during the PT was greater in 12°C than 33°C [p \u3c 0.001, η2 = 0.804, confidence interval (CI): 30.51 to 62.30]. Likewise, CAF, versus PLA, increased KJ independent of temperature (p = 0.006, η2= 0.542, CI: 3.60 to 16.86). Compared to PLA, CAF increased KJ in 12°C (p = 0.024, η2 = 0.413, CI: 1.36 to 15.55) but not in 33°C (p = 0.082, η2 = 0.272, CI: -1.84 to 25.84). CAF versus PLA in 12°C and 33°C resulted in few metabolic, cardiovascular, endocrinological, or hematological changes. Further, there were few changes in perception of mood, thirst, thermal sensations, and exertion. CAF significantly reduced feelings of muscle pain in 33°C (P \u3c 0.05), but not 12°C (P \u3e 0.05). However during exercise, Tie increased in the warm environment (peak Tre; 33°C, 39.40 ± 0.45; 12°C, 38.79 ± 0.42°C; P \u3c 0.05) but was not different in CAF versus PLA (P \u3e 0.05). Increased ambient temperature had a detrimental effect on cycling performance in both the CAF and PLA conditions. Environmental heat stress, manifested as whole-body hyperthermia diminished the ergogenic influence of CAF on cycling performance in the warm but not the cool environment. This performance decrement could not be attributed to fluid-electrolyte, cardiovascular, respiratory, metabolic, endocrine, or perceptual effects, but likely was due to the influence of hyperthermia on the central nervous system. These findings suggest that an informed decision to consume caffeine as an ergogenic aid should be predicated on ambient temperature.

Effect of ambient temperature and caffeine on performance, metabolic, cardiovascular, endocrine, hematological, perceptual, and mood measures during endurance exercise

Little is known about the effect of environmental temperature and caffeine on performance, metabolic, cardiovascular, endocrine, hematological, perceptual, and mood measures during endurance exercise. The purpose of these studies was to compare the effects of ambient temperature on caffeine ergogenicity during endurance cycling exercise. Eleven male cyclists (mean ± SD; age, 25 ± 6 y; mass, 72.6 ± 8.1 kg; V&dot;O2max, 58.7 ± 2.9 ml·kg-1·min-1) completed four exercise trials in a randomized, double blind, crossover experimental design. After cycling for 90 min (average 65 ± 7 %V&dot;O2max ) and remaining euhydrated in a warm (33 ± 1°C) or cool (12 ± 1°C) environment, subjects completed a 15-min performance trial (PT; based on total work accumulated). Subjects ingested 3 mg·kg -1 of caffeine (CAF) or placebo (PLA) 60 min prior to and 45 after beginning exercise. Total work (KJ) during the PT was greater in 12°C than 33°C [p \u3c 0.001, η2 = 0.804, confidence interval (CI): 30.51 to 62.30]. Likewise, CAF, versus PLA, increased KJ independent of temperature (p = 0.006, η2= 0.542, CI: 3.60 to 16.86). Compared to PLA, CAF increased KJ in 12°C (p = 0.024, η2 = 0.413, CI: 1.36 to 15.55) but not in 33°C (p = 0.082, η2 = 0.272, CI: -1.84 to 25.84). CAF versus PLA in 12°C and 33°C resulted in few metabolic, cardiovascular, endocrinological, or hematological changes. Further, there were few changes in perception of mood, thirst, thermal sensations, and exertion. CAF significantly reduced feelings of muscle pain in 33°C (P \u3c 0.05), but not 12°C (P \u3e 0.05). However during exercise, Tie increased in the warm environment (peak Tre; 33°C, 39.40 ± 0.45; 12°C, 38.79 ± 0.42°C; P \u3c 0.05) but was not different in CAF versus PLA (P \u3e 0.05). Increased ambient temperature had a detrimental effect on cycling performance in both the CAF and PLA conditions. Environmental heat stress, manifested as whole-body hyperthermia diminished the ergogenic influence of CAF on cycling performance in the warm but not the cool environment. This performance decrement could not be attributed to fluid-electrolyte, cardiovascular, respiratory, metabolic, endocrine, or perceptual effects, but likely was due to the influence of hyperthermia on the central nervous system. These findings suggest that an informed decision to consume caffeine as an ergogenic aid should be predicated on ambient temperature.