Rate Of Sweat Production Research Articles

Finger sweat analysis enables short interval metabolic biomonitoring in humans

Metabolic biomonitoring in humans is typically based on the sampling of blood, plasma or urine. Although established in the clinical routine, these sampling procedures are often associated with a variety of compliance issues, which are impeding time-course studies. Here, we show that the metabolic profiling of the minute amounts of sweat sampled from fingertips addresses this challenge. Sweat sampling from fingertips is non-invasive, robust and can be accomplished repeatedly by untrained personnel. The sweat matrix represents a rich source for metabolic phenotyping. We confirm the feasibility of short interval sampling of sweat from the fingertips in time-course studies involving the consumption of coffee or the ingestion of a caffeine capsule after a fasting interval, in which we successfully monitor all known caffeine metabolites as well as endogenous metabolic responses. Fluctuations in the rate of sweat production are accounted for by mathematical modelling to reveal individual rates of caffeine uptake, metabolism and clearance. To conclude, metabotyping using sweat from fingertips combined with mathematical network modelling shows promise for broad applications in precision medicine by enabling the assessment of dynamic metabolic patterns, which may overcome the limitations of purely compositional biomarkers.

Comparative Study of Efficacy and Safety of Botulinum Toxin a Injections and Subcutaneous Curettage in the Treatment of Axillary Hyperhidrosis.

Background:Primary focal axillary hyperhidrosis is a chronic distressing disorder affecting both the sexes. When the condition is refractory to conservative management, we should go for more promising therapies like intradermal botulinum toxin A (BtxA) injections in the axilla, and surgical therapies like subcutaneous curettage of sweat glands.Aims and Objectives:The aim of this study is to compare the efficacy, safety and duration of action of intradermal BtxA injections in one axilla and subcutaneous curettage of sweat glands in the other axilla of the same patient with axillary hyperhidrosis.Materials and Methods:Twenty patients (40 axillae) received intradermal BtxA injections on the right side (20 axillae) and underwent tumescent subcutaneous curettage of sweat glands on the left side (20 axillae). Sweat production rate was measured using gravimetry analyses at baseline and at 3 months after the procedure. Subjective analyses were done using hyperhidrosis disease severity scale (HDSS) score at baseline, at 3rd and 6th month after the procedure.Results:At 3 months post-treatment, the resting sweat rate in the toxin group improved by 80.32% versus 79.79% in the subcutaneous curettage method (P = 0.21). Exercise-induced sweat rate in the toxin group improved by 88.76% versus 88.8% in the subcutaneous curettage group (P = 0.9). There was a significant difference in the HDSS score after treatment with both the modalities. There were no adverse events with BtxA treatment compared to very minor adverse events with the surgical method.Conclusion:Both intradermal BtxA injections and tumescent subcutaneous curettage of sweat glands had a significant decrease in the sweat rates with no significant difference between the two modalities. Hence, in resource poor settings where affordability of BtxA injection is a constraint, subcutaneous curettage of sweat glands can be preferred which has been found equally effective with no or minimal adverse events.

Sweat Potassium Decreases with Increased Sweating in Perimenopausal Women

Objective: To investigate the relationship between rate of sweat production and sweat potassium concentration in premenopausal (PreM), perimenopausal (PeriM) and postmenopausal (PostM) women after a moderate exercise. Study Design: This is a cross-sectional study conducted in May 2012 at the Department of Physiology, University of Benin, Nigeria. Methods: Thirty healthy female volunteers comprising of PreM (aged: 22.5±0.8 yrs, n = 10), PeriM (aged: 46.5±1.1 yrs, n = 10), and PostM (aged: 52.2±0.9 yrs, n=10) participated in the study. Sweat was obtained with a sweat suction apparatus from a 120 cm circular area marked on the skin of the face and neck after a 15 min walk on a calibrated treadmill at a speed of 4.2 km/h at 27°C and a relative humidity of 85-95%, followed by measurement of sweat volume (SV) and [K]. Sweat rate (SR) was determined by dividing the volume of sweat produced by the duration of exercise. Thirst perception (TP) was self-rated using the Visual Analogue Scale (VAS). Original Research Article Amabebe et al.; BJMMR, 14(2): 1-10, 2016; Article no.BJMMR.23890 2 Results: The PeriM women demonstrated higher SR (ml/min) (P = .01) and SV (ml) (P = .0006) compared to women in the other groups: SR (PeriM = 0.12±0.01; PreM = 0.07±0.02; PostM = 0.06±0.01), and SV (PeriM = 1.7±0.2; PostM = 0.9±0.1). However, they had lower sweat [K] (mmol/l) (P = .04), compared to their PostM counterparts (PeriM = 19.98±1.5; PostM = 24.90±1.8). Furthermore, sweat [K] was inversely associated with SR (r = -0.4, P = .02). Also, change in TP (cm) was highest (P = .001) in the PeriM women (PeriM = 2.5±0.2; PreM = 2.1±0.3; PostM = 0.99±0.2). Conclusion: Although excessive sweating can lead to depletion of the body's potassium concentration, the sweat potassium concentration decreases with increased sweating especially in perimenopausal women. This requires further investigation, as it could be an adaptive mechanism inhibiting excessive potassium loss.

Distinguishing hyperhidrosis and normal physiological sweat production: new data and review of hyperhidrosis data for 1980-2013.

Hyperhidrosis is a condition in which the production of sweat is abnormally increased. No objective criteria for the diagnosis of hyperhidrosis exist, mainly because reference intervals for normal physiological sweat production at rest are unknown. The main objective of this study was to establish reference intervals for normal physiological axillary and palmar sweat production. Gravimetric testing was performed in 75 healthy control subjects. Subsequently, these results were compared with findings in a cohort of patients with hyperhidrosis and with the results derived from a review of data on hyperhidrosis published between 1980 and 2013. Approximately 90% of the controls had axillary and palmar sweat production rates of below 100 mg/5 min. In all except one of the axillary and palmar hyperhidrosis studies reviewed, average sweat production exceeded 100 mg/5 min. A sweat production rate of 100 mg/5 min as measured by gravimetric testing may be a reasonable cut-off value for distinguishing axillary and palmar hyperhidrosis from normal physiological sweat production.

Efficacy and safety of topical glycopyrrolate in patients with facial hyperhidrosis: a randomized, multicentre, double-blinded, placebo-controlled, split-face study.

Although facial hyperhidrosis has been frequently associated with a diminished quality of life, various conservative modalities for its management are still far from satisfactory. To evaluate the antiperspirant efficacy and safety of the topical glycopyrrolate on facial hyperhidrosis at specified posttreatment intervals. Thirty-nine patients with facial hyperhidrosis were enrolled and treated with 2% topical glycopyrrolate on one-half of the forehead, whereas the other half of the forehead was treated with a placebo. All patients applied topical glycopyrrolate or placebo once a day for nine successive days. Each evaluation included weighing sweat and assessing the Hyperhidrosis Disease Severity Scale (HDSS) score and any adverse effects. Compared with the placebo-treated sides, topical glycopyrrolate-treated sides showed a reduction in the rate of sweat production at the forehead of 25.16 ± 10.30% (mean ± SD) at 90 min after the first application (day 1), 29.63 ± 7.74% at 24 h after the first application (day 2) and 36.68 ± 11.41% at 24 h after eight additional successive daily applications (day 10) (all P < 0.025). There was a little more decrease in HDSS score with the topical glycopyrrolate-treated half of the forehead, but the difference was not statistically significant (P > 0.025). No serious adverse events were reported during the course of this study. Only one patient developed a transient headache after treatment. Topical glycopyrrolate application appears to be significantly effective and safe in reducing excessive facial perspiration.

Heat acclimation decreases the growth hormone response to acute constant-load exercise in the heat

ObjectiveThe major objective of this study was to elucidate the effect of heat acclimation on blood growth hormone (GH) response to moderate intensity exhausting exercise in the heat. In addition, the potential relationship between inter-individual differences in GH response to exercise and variability in exercise-induced sweat loss was investigated. DesignTwenty young men completed three exercise tests on a treadmill: H1 (walk at 60% VO2peak until exhaustion at 42°C), N (walk at 22°C; duration equal to H1) and H2 (walk until exhaustion at 42°C after a 10-day heat acclimation program). Core temperature (Tc) was recorded continuously and venous blood samples were taken before, during and after each exercise test. Exercise-induced sweat production was calculated on the basis of body mass change taking into account water intake and the volume of blood samples drawn. ResultsLower pre-exercise Tc, lower rate of rise in Tc during exercise, and prolonged time to exhaustion in H2 compared with H1 revealed that the subjects successfully achieved an acclimated state. Overall, serum GH level was higher in H1 compared with both N and H2 (p<0.001) but did not differ between the two latter trials (p>0.05). Tc correlated with serum GH concentration (r=0.615, p<0.01). Analysis of the individual data revealed a group (n=9) possessing a threshold-like pattern of the relationship between Tc and blood GH response, whereas a plateau-like pattern was evident in the rest of the subjects (n=11). Both sweat production (r=0.596; p<0.001) and the rate of sweat production (r=0.457; p<0.001) correlated with the growth hormone area under the curve. ConclusionHeat acclimation decreases the GH response to moderate intensity exhausting exercise in the heat. GH may have a modest stimulating effect on whole-body sweat production during exercise.

Wearable Sized Sudorometer and Sweat Measurement

We developed a wearable sized sudorometer to evaluate sympathetic nerve activity. The base of this device is ventilation capsule type sweating rate detection, and it contains 2 humidity sensors and a pump for ventilation. We also demonstrated sweat measurement. As a result, a remarkable increase in sweating rate after stimulations was detected. I. INTRODUCTION Skin sympathetic nerve controls the rate of sweat production. Quantification of sweat generation rate with a sudorometer is useful to investigate skin sympathetic nerve activity. To realize a long term continuous and location-independent measurement, miniaturization of sudorometer is required. Therefore, we developed a wearable sized sudorometer which base is ventilation capsule type detection. And we also demonstrated sweat detecting tests on 3 healthy adults. As a result, a remarkable increase in sweating rate after 3 types of stimulations was detected.

Topical glycopyrrolate for patients with facial hyperhidrosis

Facial hyperhidrosis may negatively impact the quality of life. Although various conservative modalities have been suggested, the condition is not often treated successfully. To examine whether topical glycopyrrolate could be an effective and safe treatment for facial hyperhidrosis. Twenty-five patients with facial hyperhidrosis were enrolled and treated with 2% topical glycopyrrolate on one half of the forehead while the other half of the forehead was treated with a placebo. The sweat production rate of the half of the forehead treated with topical glycopyrrolate was significantly reduced to 37.6+/-2.8 mg min(-1) (mean+/-SEM) compared with 102.2+/-5.5 mg min(-1) at the placebo-treated half of the forehead (P<0.001). Patients evaluated their degree of anhidrosis as excellent in six (24%) patients, good in 16 (64%), fair in two (8%) and poor in one (4%). Twenty-four patients (96%) were partially or fully satisfied with their fair to excellent anhidrosis; only one patient (who developed a transient headache after treatment) was dissatisfied with its therapeutic effect. Only seven patients (28%) experienced recurrence within 1 day while 17 patients (68%) had recurrence within 2 days. One patient (4%) remained stable for up to 4 days. Topical glycopyrrolate application appears to be effective and safe for the treatment of excessive facial sweating in primary craniofacial and secondary gustatory hyperhidrosis following sympathectomy.

Prediction of rectal temperature from ear canal temperature

Personal heat strain monitoring provides the best means for maximizing worker safety and productivity in hot jobs. The present study compared methods for reducing the environmental effect on aural canal temperature in an attempt to reduce the predictive error of a personal heat stress monitor (QST) and a simple ear thermistor (EAR). Subjects underwent three exposures in impermeable protective clothing (PC) in an environment of 30.1°C wet bulb globe temperature (WBGT) wearing either ear plugs (PLG), ear moulds (MLD) or ear moulds and earmuffs (MFS). Mean work time across all trials was 63.1 ± 7.9 min, with a mean rectal temperature at 60 min of 38.5 ± 0.1°C and a sweat production rate of 29.7 ± 8.6 g/min. Rectal temperature was used as the criterion measure of core temperature. Although group mean predictions were satisfactory, large SD of mean differences (±0.36) meant that predictive ability of QST for individuals was greatly impaired. A simple well-insulated ear thermistor showed slightly better accuracy (±0.28) as a predictor of rectal temperature across time, particularly at peak temperatures. Incorporating the predictive error of aural temperature still extended the duration of safe work times relative to ACGIH guidelines. Further investigation is still necessary to ensure that predictions based on aural temperature are accurate and safe for the worker population across varying conditions.

Physiological responses to laboratory-based soccer-specific intermittent and continuous exercise

The aim of this study was to devise a laboratory-based protocol for a motorized treadmill that was representative of work rates observed during soccer match-play. Selected physiological responses to this soccer-specific intermittent exercise protocol were then compared with steady-rate exercise performed at the same average speed. Seven male university soccer players (mean - s : age 24 - 2 years, height 1.78 - 0.1 m, mass 72.2 - 5.0 kg, VO 2max 57.8 - 4 ml·kg -1 ·min -1 ) completed a 45-min soccer-specific intermittent exercise protocol on a motorized treadmill. They also completed a continuous steady-rate exercise session for an identical period at the same average speed. The physiological responses to the laboratory-based soccer-specific protocol were similar to values previously observed for soccer match-play (oxygen consumption approximately 68% of maximum, heart rate 168 - 10 beats·min -1 ). No significant differences were observed in oxygen consumption, heart rate, rectal temperature or sweat production rate between the two conditions. Average minute ventilation was greater ( P ≪ 0.05) in intermittent exercise (81.3 - 0.2l·min -1 ) than steady-rate exercise (72.4 - 11.4l·min -1 ). The rating of perceived exertion for the session as a whole was 15 - 2 during soccer-specific intermittent exercise and 12 - 1 for continuous exercise ( P ≪ 0.05). The physiological strain associated with the laboratory-based soccer-specific intermittent protocol was similar to that associated with 45 min of soccer match-play, based on the variables measured, indicating the relevance of the simulation as a model of match-play work rates. Soccer-specific intermittent exercise did not increase the demands placed on the aerobic energy systems compared to continuous exercise performed at the same average speed, although the results indicate that anaerobic energy provision is more important during intermittent than during continuous exercise at the same average speed.

Heat stress, thermoregulation, and fluid balance in women.

As with so many aspects of exercise related research, most investigations have focused on the male of the species. In 1940, however, Hardy and Du Bois 1 undertook an investigation...

DIURNAL EFFECTS ON THERMOREGULATION AND TOLERANCE OF UNCOMPENSABLE HEAT STRESS

1537 This study examined whether the lower rectal temperature (Tre) in the morning hours would increase tolerance to uncompensable heat stress compared with trials conducted in the early afternoon. Nine males (34 y, 82 kg, 2.0 m2 surface area) performed a familiarisation trial and then 2 randomly ordered trials in the morning (0930h) and afternoon (1330h). The heat stress test consisted of intermittent walking at 3.5 km/h and seated rest at 40°C and 30% relative humidity while wearing nuclear, biological and chemical protective clothing. Initial Tre was significantly higher during the afternoon (37.1 ± 0.2°C) compared with the morning (36.8 ± 0.2°C) and these differences remained throughout the uncompensable heat stress such that final Tre was also significantly higher for the afternoon (39.2 ± 0.2°C) versus the morning (39.0 ± 0.3°C) trials. Metabolic rate, heart rate and the sweat production rate were similar during the morning and afternoon exposures. Since the rate of heat storage (100.6 ± 24 W/m2 and 96.5 ± 21.2 W/m2 for the morning and afternoon trials, respectively) and tolerance time (111 ± 22 and 107 ± 19 min for the morning and afternoon trials, respectively) were similar, calculated total heat storage also was similar for the morning (16.1 ± 2.9 kJ/kg) and afternoon heat stress exposures (15.1 ± 3.0 kJ/kg). It was concluded that trials conducted in the early afternoon were associated with an increased rectal temperature tolerated at exhaustion that offset the circadian influence on resting rectal temperature, and thus, maintained tolerance times similar to trials conducted in the morning.

PRE-COOLING REDUCES THERMOREGULATORY STRAIN AND SKIN BLOOD FLOW DURING EXERCISE

1515 It has been suggested that fatigue during exercise in the heat occurs when rectal temperature approaches 39.7°C. Indeed, a number of studies have reported that rectal temperature increases less rapidly following pre-cooling and that as a consequence, time to exhaustion is prolonged. This investigation examined the thermoregulatory effector response (specifically skin blood flow) during exercise with and without prior pre-cooling. Six physically active male subjects cycled intermittental at 65% VO2max in an ambient temperature of 22°C for 45 min on two occassions (control and pre-cooling). The pre-cooling (PC) strategy consisted of shower immersion for a duration of 60 min at a water temperature of 28°C which was subsequently reduced by 2°C every 20 min. Rectal temperature (Tr) was measured 10cm beyond the external anal spincter and sweat production rate (SPR) estimated from nude body mass measurement before and after exercise. Forearm skin blood flow (Skbf) was measured by laser Doppler fluximetry and lactate determined in an arterialised capillary sample. There were no significant differences in baseline heart rate, Tr, Skbf or lactate between trials. However, skin temperatures (Tsk) were significantly reduced as a result of pre-cooling (P<0.05). During exercise, the increase in Tr was significantly greater in the control (0.89±0.11°C) compared with the pre-cooling trial (0.63±0.16°C) (P<0.05). This was associated with a significant reduction in Skbf (57.2±16.1 vs 88.3±21.2PU) and a trend towards reduced weight loss (0.68±0.12 vs 1.40±0.38kg) during the pre-cooling trial. These data indicate that pre-cooling was effective in reducing Skbf and suggest that following pre-cooling central blood volume may be augmented which may reduce any thermoregulatory competition for muscle blood flow.

Sweating: Fluid and Ion Losses and Replacement

In the horse, sweat is produced by apocrine glands which are present over most haired and nonhaired skin. Although sweat secretion is initiated under a number of circumstances, the central drive for sweating in response to a thermal stimulus is the primary mechanism for its production. Sweating is an essential and primary mechanism for heat dissipation during exercise or exposure to hot ambient conditions. The rate of sweat production will reflect the interaction of numerous factors, including exercise intensity, ambient conditions, state of hydration, and the training or heat acclimation status of the individual horse. Thus, the sweating rates produced in response to an exercise-induced thermal load can be further increased by high ambient temperature or humidity which reduces evaporative efficiency, thereby contributing to the rate of rise in core body temperature. Equine sweat is an isotonic to slightly hypertonic secretion with sodium, chloride, and potassium contributing the major ionic components. The ionic composition of equine sweat is largely rate dependent and therefore is affected by factors such as ambient conditions and exercise intensity which result in elevations in sodium concentration in response to increases in sweating rate. Large sweat fluid losses associated with prolonged exercise will incur significant ion deficits, leading to alterations in skeletal muscle ion content and the potential for muscular dysfunction. With respect to exercise performance, however, the more important consequence of sweat fluid losses is the impairment of temperature regulation that accompanies severe dehydration. Although it is advantageous to restore a proportion of the fluid and ion losses incurred during prolonged exercise, few strategies will fully and safely replace the electrolyte losses incurred. Nevertheless, daily electrolyte supplementation of a good-quality diet will provide an effective method of replacing sweat ion losses during training and competition under most ambient conditions.

The influence of bicycle exercise, with or without hand immersion in cold water, on forearm sweating in young and middle‐aged women

Forearm sweat production rate (SPR) and external auditory meatal temperature (TEAM) were examined in five young and five middle-aged women in response to intermittent exercise, on three separate occasions. The first experiment was a control study, while in the second study the left hand was immersed in cold water at the onset of sweating during each exercise bout, and in the third study this immersion was accompanied by venous occlusion of the upper left arm. TEAM increased by 0.5 degrees C during exercise with no significant differences between the groups on any occasion. The young women displayed a greater peak SPR during exercise in the control than the middle-aged women (52.5 +/- 23.9 vs. 16.7 +/- 6.5 mg cm2 h-1, P less than 0.001). With hand immersion, peak SPR was depressed to 14.0 +/- 4.6 mg cm2 h-1 (P less than 0.001) in the young women and to 13.1 +/- 4.5 mg cm2 h-1 in the middle-aged (P less than 0.05). With hand immersion and venous occlusion the peak SPR in young women increased (43.0 +/- 9.2 mg cm2 h-1). In the older women SPR was 14.9 +/- 6.1 mg cm2 h-1, which was not different from either control or cold-immersed values. Thus, forearm SPR during low-intensity intermittent exercise is greater in young compared with middle-aged women, despite similar changes in TEAM. The response to hand immersion in cold water was more marked in the young subjects.

Quantitative analysis of the local effect of skin temperature on sweating.

Effects of local skin temperature on sweat gland activity were analyzed quantitatively by measuring changes in the rates of thermal sweating and of drug-induced sweating by local heating. The data indicates that a rise in local temperature causes an accelerated increase in the rate of sweat production, the Q10 being around 2.5 regardless of the basal sweat rate with some individual variations. Local heating apparently facilitates transmitter release at the neuroglandular junction and augments glandular responsiveness, their significances being comparable.

Sweat production in children's feet.

The rate of sweating from the feet of children aged 4–14 yr was measured by collecting the sweat produced at rest into weighed socks. Although individual variation was great, sweat production per unit surface area remained fairly constant throughout childhood. Sweat production per foot, however, showed an increase with age and foot size, leveling off in early adolescence. These results that the rate of sweat production from each eccrine gland increases as the foot grows. The rate of sweating from the feet of childen aged 4‐14yr was measures by collecting the sweat producer at rest into weighted socks. Although individual variation was great, sweat production per unit surface area remained fairly constant throughout childhood. Sweat production per foot, however, showed an increase with age and foot size, levelling off in early adolescence. These results suggest that the rate of sweat production from each eccrine gland increases as the foot grows.

Studies on the nature of sweat gland 'fatigue' in the goat.

1. The nature of the ;fatigue' of sweating that occurs in the goat upon exposure to environmental conditions of 40 degrees C/26 degrees C (dry bulb/wet bulb) has been examined.2. Heat exposure activated all the sweat glands and the decrement in sweating which occurred was due to a decline in the amount of sweat produced by each gland.3. The decline in sweating activity was associated with a decrease in sweat gland volume and a thickening of the glandular wall. The restoration of sweat gland function took approximately 5-6 hr after removing the animal from the hot environment but the restoration of sweat gland volume took longer.4. The volume of sweat produced was greater than the decrease in sweat gland volume and it is concluded that ;fatigue' is due to the rate of expulsion exceeding the rate of sweat production.5. Repeated intravenous injections of adrenaline at 40 degrees C resulted in a decline in sweat output and reduced the normal glandular response to heat exposure.

The relation between sweat rate and weight loss when sweat is dripping off the body.

1. The relation between the rate of sweat production, S, and the rate of weight loss, W, has been examined under conditions in which the rate of evaporation was small.2. S could be found from W provided that a film of liquid was maintained over the skin surface. This could be achieved initially by immersing the subject in water containing detergent. Thereafter the film was maintained so long as the rate of weight loss exceeded about 10 g/min.3. When the rate of weight loss was changing and the rate of evaporation was constant, S could be calculated as W + 2.5 W.4. When the subject was constantly sprayed with water while being weighed, the correction for W became negligible. In this case there was no lower limit to the sweat rate which could be measured, but spraying considerably reduced the accuracy of the measurement.5. The output of sweat from a ventilated capsule on the forearm correlated well with estimates of central sweating drive based on weight measurements corrected for hidromeiosis.