The Importance of Maintaining and Improving a Healthy Gut Microbiota in Athletes as a Preventive Strategy to Improve Heat Tolerance and Acclimatization

Exposure to passive heat (acclimation) and exercise under hot conditions (acclimatization), known as heat acclimation (HA), are methods that athletes include in their routines to promote faster recovery and enhance physiological adaptations and performance under hot conditions. Despite the potential positive effects of HA on health and physical performance in the heat, these stimuli can negatively affect gut health, impairing its functionality and contributing to gut dysbiosis. Blood redistribution to active muscles and peripheral vascularization exist during exercise and HA stimulus, promoting intestinal ischemia. Gastrointestinal ischemia can impair intestinal permeability and aggravate systemic endotoxemia in athletes during exercise. Systemic endotoxemia elevates the immune system as an inflammatory responses in athletes, impairing their adaptive capacity to exercise and their HA tolerance. Better gut microbiota health could benefit exercise performance and heat tolerance in athletes. This article suggests that: (1) the intestinal modifications induced by heat stress (HS), leading to dysbiosis and altered intestinal permeability in athletes, can decrease health, and (2) a previously acquired microbial dysbiosis and/or leaky gut condition in the athlete can negatively exacerbate the systemic effects of HA. Maintaining or improving the healthy gut microbiota in athletes can positively regulate the intestinal permeability, reduce endotoxemic levels, and control the systemic inflammatory response. In conclusion, strategies based on positive daily habits (nutrition, probiotics, hydration, chronoregulation, etc.) and preventing microbial dysbiosis can minimize the potentially undesired effects of applying HA, favoring thermotolerance and performance enhancement in athletes.

Association between heat and hospital admissions in people with disabilities in South Korea: a nationwide, case-crossover study

BACKGROUND

Despite extensive findings on the hazardous impacts of environmental heat exposure, little is known about the effect on people with disabilities. This study aimed to estimate the association between environmental heat exposure and emergency department admissions for people with disabilities compared with people without disabilities.

METHODS

In this nationwide, case-crossover study, we linked data on emergency department admissions (cases) for any cause in the warm season in South Korea from the Korean National Health Insurance Service (NHIS)-National Sample Cohort database (a nationally representative database of 1 million systematically sampled beneficiaries covering all ages) from Jan 1, 2002, to Dec 31, 2019, and short-term daily mean temperature exposure (measured via Google Earth Engine at a 9 km spatial grid, aggregated to district). We defined beneficiaries with disabilities as those who were registered as disabled in the NHIS; disabilities included in our study were physical disability, brain lesion disorders, blindness or vision loss, and deafness or hearing loss. Other types of disability were not included for confidentiality reasons. A time-stratified case-crossover design, in which participants served as their own control, was used with conditional logistic regression to estimate the association between heat and emergency department admissions in people with and without disabilities.

FINDINGS

23 792 emergency department admissions were recorded for 59 527 people with disabilities. Of these 23 792 admissions, 10 234 (43·0%) individuals were female and 13 558 (57·0%) were male. The odds ratio (OR) of emergency department admissions associated with heat (99th temperature percentile vs 75th percentile) was 1·15 (95% CI 1·07-1·24) in people with disabilities and 1·06 (1·04-1·09) in people without disabilities. The annual excess number of emergency department admissions attributable to heat per 100 000 persons-years was 27·81 admissions (95% CI 9·20-45·69) and excess medical costs were US$638 739·47 (95% CI 201 900·12-1 059 641·87) in people with disabilities; these values were more than four times that of the non-disabled population. People with brain lesion disorders, people with severe physical disabilities, female individuals, and those aged 65 years or older showed higher heat risks. The risks of emergency department admissions due to mental disorder (1·89, 95% CI 1·18-3·00) and respiratory diseases (1·34, 1·06-1·70) also showed higher heat risks than for the other two analysed causes of admission (cardiovascular and genitourinary diseases).

INTERPRETATION

Heat was associated with increased risk of emergency department admissions for people with and without disabilities, but the risk appeared to be higher for those with disabilities. These results can inform policy makers when establishing action plans for people with disabilities.

FUNDING

National Research Foundation of Korea, the South Korean Ministry of Environment, and the South Korean Ministry of Education.

Experimental research in environmentally induced hyperthermic older persons: A systematic quantitative literature review mapping the available evidence

The heat-related health burden is expected to persist and worsen in the coming years due to an aging global population and climate change. Defining the breadth and depth of our understanding of age-related changes in thermoregulation can identify underlying causes and strategies to protect vulnerable individuals from heat. We conducted the first systematic quantitative literature review to provide context to the historical experimental research of healthy older adults - compared to younger adults or unhealthy age matched cases - during exogenous heat strain, focusing on factors that influence thermoregulatory function (e.g. co-morbidities). We identified 4,455 articles, with 147 meeting eligibility criteria. Most studies were conducted in the US (39%), Canada (29%), or Japan (12%), with 71% of the 3,411 participants being male. About 71% of the studies compared younger and older adults, while 34% compared two groups of older adults with and without factors influencing thermoregulation. Key factors included age combined with another factor (23%), underlying biological mechanisms (18%), age independently (15%), influencing health conditions (15%), adaptation potential (12%), environmental conditions (9%), and therapeutic/pharmacological interventions (7%). Our results suggest that controlled experimental research should focus on the age-related changes in thermoregulation in the very old, females, those with overlooked chronic heat-sensitive health conditions (e.g. pulmonary, renal, mental disorders), the impact of multimorbidity, prolonged and cumulative effects of extreme heat, evidence-based policy of control measures (e.g. personal cooling strategies), pharmaceutical interactions, and interventions stimulating protective physiological adaptation. These controlled studies will inform the directions and use of limited resources in ecologically valid fieldwork studies.

A century of exercise physiology: concepts that ignited the study of human thermoregulation. Part 3: Heat and cold tolerance during exercise

In this third installment of our four-part historical series, we evaluate contributions that shaped our understanding of heat and cold stress during occupational and athletic pursuits. Our first topic concerns how we tolerate, and sometimes fail to tolerate, exercise-heat stress. By 1900, physical activity with clothing- and climate-induced evaporative impediments led to an extraordinarily high incidence of heat stroke within the military. Fortunately, deep-body temperatures > 40 °C were not always fatal. Thirty years later, water immersion and patient treatments mimicking sweat evaporation were found to be effective, with the adage of cool first, transport later being adopted. We gradually acquired an understanding of thermoeffector function during heat storage, and learned about challenges to other regulatory mechanisms. In our second topic, we explore cold tolerance and intolerance. By the 1930s, hypothermia was known to reduce cutaneous circulation, particularly at the extremities, conserving body heat. Cold-induced vasodilatation hindered heat conservation, but it was protective. Increased metabolic heat production followed, driven by shivering and non-shivering thermogenesis, even during exercise and work. Physical endurance and shivering could both be compromised by hypoglycaemia. Later, treatments for hypothermia and cold injuries were refined, and the thermal after-drop was explained. In our final topic, we critique the numerous indices developed in attempts to numerically rate hot and cold stresses. The criteria for an effective thermal stress index were established by the 1930s. However, few indices satisfied those requirements, either then or now, and the surviving indices, including the unvalidated Wet-Bulb Globe-Thermometer index, do not fully predict thermal strain.

A physiological approach for assessing human survivability and liveability to heat in a changing climate

Most studies projecting human survivability limits to extreme heat with climate change use a 35 °C wet-bulb temperature (Tw) threshold without integrating variations in human physiology. This study applies physiological and biophysical principles for young and older adults, in sun or shade, to improve current estimates of survivability and introduce liveability (maximum safe, sustained activity) under current and future climates. Our physiology-based survival limits show a vast underestimation of risks by the 35 °C Tw model in hot-dry conditions. Updated survivability limits correspond to Tw~25.8-34.1 °C (young) and ~21.9-33.7 °C (old)-0.9-13.1 °C lower than Tw = 35 °C. For older female adults, estimates are ~7.2-13.1 °C lower than 35 °C in dry conditions. Liveability declines with sun exposure and humidity, yet most dramatically with age (2.5-3.0 METs lower for older adults). Reductions in safe activity for younger and older adults between the present and future indicate a stronger impact from aging than warming.

Effects of Medications on Heat Loss Capacity in Chronic Disease Patients: Health Implications Amidst Global Warming

Pharmacological agents used to treat or manage diseases can modify the level of heat strain experienced by chronically ill and elderly patients via different mechanistic pathways. Human thermoregulation is a crucial homeostatic process that maintains body temperature within a narrow range during heat stress through dry (i.e., increasing skin blood flow) and evaporative (i.e., sweating) heat loss, as well as active inhibition of thermogenesis, which is crucial to avoid overheating. Medications can independently and synergistically interact with aging and chronic disease to alter homeostatic responses to rising body temperature during heat stress. This review focuses on the physiologic changes, with specific emphasis on thermolytic processes, associated with medication use during heat stress. The review begins by providing readers with a background of the global chronic disease burden. Human thermoregulation and aging effects are then summarized to give an understanding of the unique physiologic changes faced by older adults. The effects of common chronic diseases on temperature regulation are outlined in the main sections. Physiologic impacts of common medications used to treat these diseases are reviewed in detail, with emphasis on the mechanisms by which these medications alter thermolysis during heat stress. The review concludes by providing perspectives on the need to understand the effects of medication use in hot environments, as well as a summary table of all clinical considerations and research needs of the medications included in this review. SIGNIFICANCE STATEMENT: Long-term medications modulate thermoregulatory function, resulting in excess physiological strain and predisposing patients to adverse health outcomes during prolonged exposures to extreme heat during rest and physical work (e.g., exercise). Understanding the medication-specific mechanisms of altered thermoregulation has importance in both clinical and research settings, paving the way for work toward refining current medication prescription recommendations and formulating mitigation strategies for adverse drug effects in the heat in chronically ill patients.

Quantitative assessment of painful diabetic peripheral neuropathy after high-frequency spinal cord stimulation: a pilot study

OBJECTIVE

Randomized trials have demonstrated efficacy of spinal cord stimulation (SCS) for treatment of painful diabetic neuropathy (PDN). Preliminary data suggested that treatment of PDN with high-frequency SCS resulted in improvements on neurological examination. The purpose of the present study was to explore whether patients with PDN treated with high-frequency SCS would have improvements in lower-extremity peripheral nerve function.

DESIGN

Prospective cohort study in an outpatient clinical practice at a tertiary care center.

METHODS

Patients with PDN were treated with high-frequency SCS and followed up for 12 months after SCS implantation with clinical outcomes assessments of pain intensity, neuropathic symptoms, and neurological function. Small-fiber sudomotor function was assessed with the quantitative sudomotor axon reflex test (QSART), and large-fiber function was assessed with nerve conduction studies (NCS). Lower-extremity perfusion was assessed with laser Doppler flowmetry.

RESULTS

Nine patients completed 12-month follow-up visits and were observed to have improvements in lower-extremity pain, weakness, and positive sensory symptoms. Neuropathy impairment scores were improved, and 2 patients had recovery of sensory responses on NCS. A reduction in sweat volume on QSART was observed in the proximal leg but not at other sites. No significant differences were noted in lower-extremity perfusion or NCS as compared with baseline.

CONCLUSIONS

The improvement in pain relief was concordant with improvement in neuropathy symptoms. The findings from this study provide encouraging preliminary data in support of the hypothesis of a positive effect of SCS on peripheral neuropathy, but the findings are based on small numbers and require further evaluation.

TRIAL REGISTRATION

ClinicalTrials.gov ID NCT03769675.

Dermatoses in overweight and obese children and their relationship with insulin and skin color

BACKGROUND/AIM

The aim of the present study was to investigate the prevalence of obesity-related dermatoses in obese children, and the association between these dermatoses and insulin resistance as well as skin color.

METHODS

Obese, overweight, and normal weight children according to body mass index who were followed up and treated in the outpatient clinics were included in the study. Dermatological examinations of the participants were performed, and fasting insulin and glucose levels were checked.

RESULTS

The obese and overweight children were evaluated as the patient group (70 girls, 41 boys, mean age: 12.37 ± 3.14 years). One hundred one healthy children with normal weight were determined as the control group (59 girls, 42 boys, mean age: 12.15 ± 2.43). The first five common dermatoses in the patient group when compared with the control group were keratosis pilaris (KP), striae distensae, hyperhidrosis, acanthosis nigricans (AN), and plantar hyperkeratosis. The first five dermatoses which were positively correlated with formation and insulin resistance were KP, striae distensae, AN, hyperhidrosis, and plantar hyperkeratosis. According to the Fitzpatrick skin scale, we found that the darker the skin color, the higher the probability of AN and KP (OR, 0.298; 95% CI, 0.106-0.834, p = 0.021; OR, 0.306; 95% CI, 0.117-0.796, p = 0.015, respectively).

CONCLUSION

Some dermatoses associated with obesity and insulin resistance were not found in obese children, or there was no significant association. These results indicate that many skin morbidities may be prevented by preventing and treating obesity and insulin resistance in the early period.

Higher Temperatures in Socially Vulnerable US Communities Increasingly Limit Safe Use of Electric Fans for Cooling

As the globe warms, people will increasingly need affordable, safe methods to stay cool and minimize the worst health impacts of heat exposure. One of the cheapest cooling methods is electric fans. Recent research has recommended ambient air temperature thresholds for safe fan use in adults. Here we use hourly weather reanalysis data (1950-2021) to examine the temporal and spatial evolution of ambient climate conditions in the continental United States (CONUS) considered safe for fan use, focusing on high social vulnerability index (SVI) regions. We find that although most hours in the day are safe for fan use, there are regions that experience hundreds to thousands of hours per year that are too hot for safe fan use. Over the last several decades, the number of hours considered unsafe for fan use has increased across most of the CONUS (on average by ∼70%), with hotspots across the US West and South, suggesting that many individuals will increasingly need alternative cooling strategies. People living in high-SVI locations are 1.5-2 times more likely to experience hotter climate conditions than the overall US population. High-SVI locations also experience higher rates of warming that are approaching and exceeding important safety thresholds that relate to climate adaptation. These results highlight the need to direct additional resources to these communities for heat adaptive strategies.

Pharmacovigilance-based drug repurposing: searching for putative drugs with hypohidrosis or anhidrosis adverse events for use against hyperhidrosis

BACKGROUND

Drug repurposing refers to the application of existing drugs to new therapeutic indications. As phenotypic indicators of human drug response, drug side effects may provide direct signals and unique opportunities for drug repurposing.

OBJECTIVES

We aimed to identify drugs frequently associated with hypohidrosis or anhidrosis adverse reactions (that is, the opposite condition of hyperhidrosis) from the pharmacovigilance database, which could be potential candidates as anti-hyperhidrosis treatment agents.

METHODS

In this observational, retrospective, pharmacovigilance study, adverse event reports of hypohidrosis or anhidrosis in the US Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) were assessed between January 2004 and December 2021 using reporting odds ratio (ROR) estimates and categorized by the World Health Organization Anatomical Therapeutic Chemical (ATC) classification code. The onset time of drug-associated hypohidrosis or anhidrosis was also examined.

RESULTS

There were 540 reports of 192 drugs with suspected drug-associated hypohidrosis or anhidrosis in the FAERS database, of which 39 drugs were found to have statistically significant signals. Nervous system drugs were most frequently reported (187 cases, 55.82%), followed by alimentary tract and metabolism drugs (35 cases, 10.45%), genitourinary system and sex hormones (28 cases, 8.36%), and dermatologicals (22 cases, 6.57%). The top 3 drug subclasses were antiepileptics, drugs for urinary frequency and incontinence, and antidepressants. Taking disproportionality signals, pharmacological characteristics of drugs and appropriate onset time into consideration, the main putative drugs for hyperhidrosis were glycopyrronium, solifenacin, oxybutynin, and botulinum toxin type A. Other drugs, such as topiramate, zonisamide, agalsidase beta, finasteride, metformin, lamotrigine, citalopram, ciprofloxacin, bupropion, duloxetine, aripiprazole, prednisolone, and risperidone need more investigation.

CONCLUSIONS

Several candidate agents among hypohidrosis or anhidrosis-related drugs were identified that may be redirected for diminishing sweat production. There are affirmative data for some candidate drugs, and the remaining proposed candidate drugs without already known sweat reduction mechanisms of action should be further explored.

When to investigate for secondary hyperhidrosis: data from a retrospective cohort of all causes of recurrent sweating

Background: Identification of underlying diseases is crucial for secondary hyperhidrosis management, but data are lacking to guide appropriate investigation.Objective: To describe aetiologies of recurrent sweating in a hospital setting and the diagnostic performance parameters of their respective clinical/biological features.Patients and Methods: We performed a monocentric evaluative study in a tertiary care centre. Patients with recurrent generalised sweating were selected via the Clinical Data Warehouse (CDW) by screening all electronic hospital documents from the year 2018 using a keyword-based algorithm. All in and out-patients aged ≥ 18 years having reported recurrent sweating for at least 2 weeks in 2018 were included, with a minimum one-year follow-up after symptoms' onset.Results: A total of 420 patients were included. Over 130 different aetiologies were identified; 70 patients (16.7%) remained without diagnosis. Solid organ cancers (14.3% with 13 lung cancers), haematologic malignancies (14.0% with 35 non-Hodgkin's lymphomas) and Infectious Diseases (10.5% including 13 tuberculosis) were the most frequent diagnoses. Other aetiologies were gathered into inflammatory (16.9%) and non-inflammatory (27.6%) conditions. To distinguish non-inflammatory and undiagnosed hyperhidrosis from other causes, fever had a specificity of 94%, impaired general condition a sensitivity of 78%, and C-reactive protein (CRP) > 5.6 mg/l a positive predictive value of 0.86. Symptoms' duration over 1 year was in favour of non-infectious and non-malignant causes (94% specificity).Conclusions: We identified fever, impaired general condition, duration, and CRP as helpful orientation parameters to assess the need for complementary explorations for hyperhidrosis. The study provides a diagnostic algorithm for the investigation of recurrent sweating.KEY MESSAGESIn a hospital setting, malignancies and infections are the most frequently associated diseases, but 1/5 remain without diagnosis.Fever is a specific but not sensitive sign to distinguish inflammatory conditions.Over 1 year duration of symptoms significantly reduce the probability of malignancy or infection as the underlying diagnosis.

The temporal association of hyperhidrosis and its comorbidities - a nationwide hospital-based cohort study

BACKGROUND

Research on hyperhidrosis comorbidities has documented the co-occurrence of diseases but has not provided information about temporal disease associations.

OBJECTIVE

To investigate the temporal disease trajectories of individuals with hospital-diagnosed hyperhidrosis.

METHODS

This is a hospital-based nationwide cohort study including all patients with a hospital contact in Denmark between 1994 and 2018. International Classification of Diseases version-10 diagnoses assigned to inpatients, outpatients and emergency department patients were collected from the Danish National Patient Register. The main outcome was the temporal disease associations occurring in individuals with hyperhidrosis, which was assessed by identifying morbidities significantly associated with hyperhidrosis and then examining whether there was a significant order of these diagnoses using binomial tests.

RESULTS

Overall, 7 191 519 patients were included. Of these, 8758 (0.12%) patients had localized hyperhidrosis (5674 female sex [64.8%]; median age at first diagnosis 26.9 [interquartile range 21.3-36.1]) and 1102 (0.015%) generalized hyperhidrosis (606 female sex [59.9%]; median age at first diagnosis 40.9 [interquartile range 26.4-60.7]). The disease trajectories comprised pain complaints, stress, epilepsy, respiratory and psychiatric diseases. The most diagnosed morbidities for localized hyperhidrosis were abdominal pain (relative risk [RR] = 121.75; 95% Confidence Interval [CI] 121.14-122.35; P < 0.001), soft tissue disorders (RR = 151.19; 95% CI 149.58-152.80; P < 0.001) and dorsalgia (RR = 160.15; 95% CI 158.92-161.38; P < 0.001). The most diagnosed morbidities for generalized hyperhidrosis were dorsalgia (RR = 306.59; 95% CI 302.17-311.02; P < 0.001), angina pectoris (RR = 411.69; 95% CI 402.23-421.16; P < 0.001) and depression (RR = 207.92; 95% CI 202.21-213.62; P < 0.001). All these morbidities were diagnosed before hyperhidrosis.

CONCLUSIONS

This paper ascertains which hospital-diagnosed morbidities precede hospital-diagnosed hyperhidrosis. As hyperhidrosis mainly is treated in the primary health care sector, the trajectories suggests that these morbidities may lead to a worse disease course of hyperhidrosis that necessitates treatment in hospitals. Treating these morbidities may improve the disease course of hyperhidrosis.

Foxa1 mediates eccrine sweat gland development through transcriptional regulation of Na-K-ATPase expression

Eccrine sweat glands (ESGs) perform critical functions in temperature regulation in humans. Foxa1 plays an important role in ESG maturation and sweat secretion. Its molecular mechanism, however, remains unknown. This study investigated the expression of Foxa1 and Na-K-ATPase (NKA) in rat footpads at different development stages using immunofluorescence staining, qRT-PCR, and immunoblotting. Also, bioinformatics analysis and Foxa1 overexpression and silencing were employed to evaluate Foxa1 regulation of NKA. The results demonstrated that Foxa1 was consistently expressed during the late stages of ESGs and had a significant role in secretory coil maturation during sweat secretion. Furthermore, the mRNA abundance and protein expression of NKA had similar accumulation trends to those of Foxa1, confirming their underlying connections. Bioinformatics analysis revealed that Foxa1 may interact with these two proteins via binding to conserved motifs in their promoter regions. Foxa1 gain-of-function and loss-of-function experiments in Foxa1-modified cells demonstrated that the activities of NKA were dependent on the presence of Foxa1. Collectively, these data provided evidence that Foxa1 may influence ESG development through transcriptional regulation of NKA expression.

Establishment and characterization of immortalized sweat gland myoepithelial cells

Sweat glands play an important role in thermoregulation via sweating, and protect human vitals. The reduction in sweating may increase the incidence of hyperthermia. Myoepithelial cells in sweat glands exhibit stemness characteristics and play a major role in sweat gland homeostasis and sweating processes. Previously, we successfully passaged primary myoepithelial cells in spheroid culture systems; however, they could not be maintained for long under in vitro conditions. No myoepithelial cell line has been established to date. In this study, we transduced two immortalizing genes into primary myoepithelial cells and developed a myoepithelial cell line. When compared with primary sweat gland cells, the immortalized myoepithelial cells (designated "iEM") continued to form spheroids after the 4th passage and expressed α-smooth muscle actin and other proteins that characterize myoepithelial cells. Furthermore, treatment with small compounds targeting the Wnt signaling pathways induced differentiation of iEM cells into luminal cells. Thus, we successfully developed an immortalized myoepithelial cell line having differentiation potential. As animal models are not useful for studying human sweat glands, our cell line will be helpful for studying the mechanisms underlying the pathophysiology of sweating disorders.

Can thiol-disulfide balance be an indicator of oxidative stress for hyperhidrosis?

BACKGROUND

Hyperhidrosis is responsible for various causes. The increased reactive oxygen radical production with insufficient antioxidant mechanism capacity may play a role in the etiopathogenesis of hyperhidrosis. It is probable to gather data about oxidative stress by detecting plasma thiol/disulfide ratio. The aim of this study was to determine whether thiol-disulfide balance changes in patients with hyperhidrosis.

METHODS

The files of patients who were diagnosed with hyperhidrosis in the dermatology outpatient clinic between 2015 and 2018 and whose native thiol, total thiol, and disulfide values were examined for any reason were examined.

RESULTS

Seventy-three patients were included in the study. 33 of the patients with hyperhidrosis were primary. Mean age; for primary hyperhidrosis patients (PHH) = 26.36 ± 7.61, primary hyperhidrosis (PHH) control group = 27.16 ± 7.94; secondary hyperhidrosis (SHH) patients = 47.88 ± 12.29, SHH control (45.40 ± 12.02). The native thiol values of PHH (469.93 ± 56.82 μmol/L) were higher than SHH (440.64 ± 62.72) (p = 0.024). However, as a result of thiol-disulfide comparison between hyperhidrosis patients (PHH and SHH) and control groups, disulfide levels increased (p = 0.04). In the PHH group, total thiol was measured as 512 ± 54.84 μmol/L, and SHH was measured as 484.11 ± 58.9 μmol/L, (p = 0.074).

CONCLUSION

Serum thiol levels in SHH increased more than PHH. As a result of thiol-disulfide comparison between hyperhidrosis patients and control groups, the balance shifted in favor of disulfide and oxidative side.

Significance of Metabolite Ratios in the Interpretation of Segmental Hair Testing Results-Differentiation of Single from Chronic Morphine Use in a Case Series

In morphine intoxication cases, forensic toxicologists are frequently confronted with the question of if the individual was opioid-tolerant or opioid-naïve, which can be investigated by hair analysis. However, interpretation of results can be challenging. Here, we report on hair testing for morphine and its metabolite hydromorphone following morphine intoxication without tolerance and upon chronic use. Two consecutive hair samples were collected after a non-fatal intoxication. Analysis comprised short hair segments and their initial wash water solutions. In the intoxications, morphine and hydromorphone levels were 3.3 to 56 pg/mg and at maximum 9.8 pg/mg, respectively. Both levels and hydromorphone to morphine ratios were significantly lower compared to chronic morphine use. In the non-fatal intoxication, the highest hydromorphone to morphine ratio was obtained in the segment corresponding to the time of intoxication. Morphine ratios of wash to hair were significantly higher in the intoxications compared to chronic use, being indicative of sweat/sebum contamination. We recommend including the analysis of hydromorphone and the initial wash solution in cases of morphine intoxications. Our study demonstrates that hydromorphone to morphine ratios can help in distinguishing single from chronic morphine use and in estimating the period of exposure when a consecutive hair sample can be collected in survived intoxications.

Hot weather and heat extremes: health risks

Hot ambient conditions and associated heat stress can increase mortality and morbidity, as well as increase adverse pregnancy outcomes and negatively affect mental health. High heat stress can also reduce physical work capacity and motor-cognitive performances, with consequences for productivity, and increase the risk of occupational health problems. Almost half of the global population and more than 1 billion workers are exposed to high heat episodes and about a third of all exposed workers have negative health effects. However, excess deaths and many heat-related health risks are preventable, with appropriate heat action plans involving behavioural strategies and biophysical solutions. Extreme heat events are becoming permanent features of summer seasons worldwide, causing many excess deaths. Heat-related morbidity and mortality are projected to increase further as climate change progresses, with greater risk associated with higher degrees of global warming. Particularly in tropical regions, increased warming might mean that physiological limits related to heat tolerance (survival) will be reached regularly and more often in coming decades. Climate change is interacting with other trends, such as population growth and ageing, urbanisation, and socioeconomic development, that can either exacerbate or ameliorate heat-related hazards. Urban temperatures are further enhanced by anthropogenic heat from vehicular transport and heat waste from buildings. Although there is some evidence of adaptation to increasing temperatures in high-income countries, projections of a hotter future suggest that without investment in research and risk management actions, heat-related morbidity and mortality are likely to increase.

A Case-Series Observation of Sweat Rate Variability in Endurance-Trained Athletes

Adequate fluid replacement during exercise is an important consideration for athletes, however sweat rate (SR) can vary day-to-day. The purpose of this study was to investigate day-to-day variations in SR while performing self-selected exercise sessions to evaluate error in SR estimations in similar temperature conditions. Thirteen endurance-trained athletes completed training sessions in a case-series design 1x/week for a minimum 30 min of running/biking over 24 weeks. Body mass was recorded pre/post-training and corrected for fluid consumption. Data were split into three Wet-Bulb Globe Thermometer (WBGT) conditions: LOW (<10 °C), MOD (10–19.9 °C), HIGH (>20 °C). No significant differences existed in exercise duration, distance, pace, or WBGT for any group (p > 0.07). Significant differences in SR variability occurred for all groups, with average differences of: LOW = 0.15 L/h; MOD = 0.14 L/h; HIGH = 0.16 L/h (p < 0.05). There were no significant differences in mean SR between LOW-MOD (p > 0.9), but significant differences between LOW-HIGH and MOD-HIGH (p < 0.03). The assessment of SR can provide useful data for determining hydration strategies. The significant differences in SR within each temperature range indicates a single assessment may not accurately represent an individual’s typical SR even in similar environmental conditions.

Paroxysmal localized Hyperhidrosis, a case-report: When excessive sweating occurs in combination with severe headaches

BACKGROUND

Paroxysmal localized hyperhidrosis is a rare disorder of the central autonomic nervous system. No association between paroxysmal hyperhidrosis and severe headache has been previously described in literature.Case description: A 65-year-old woman with idiopathic paroxysmal localized hyperhidrosis combined with severe holocranial headache attacks is described in this case report. Extensive diagnostic testing by means of laboratory examinations, 24-hour urinalyses, chest X-ray, abdominal ultrasound and computed tomography scans, and brain and spinal cord magnetic resonance imaging could not identify an underlying disorder. A diagnosis of idiopathic paroxysmal localized hyperhidrosis was made, and the patient was successfully treated with clonidine 0.075 mg three times a day, without any side effects.

CONCLUSION

Paroxysmal localized hyperhidrosis is a rare central autonomic nervous system disorder that can occur in combination with severe headache. Both the headache and paroxysmal hyperhidrosis complaints were treated effectively with clonidine in the patient described in this case-report.

Oxybutynin-Induced Hyperthermia in a Patient With Parkinson's Disease

Impaired thermoregulation and heat intolerance may be intrinsic to autonomic dysfunction in Parkinson's disease due to disturbances in perspiration regulation. Thermoregulatory impairment leading to hyperthermia/heatstroke can be accentuated with the usage of anticholinergics, which block the ability to sweat. Oxybutynin chloride is one of the most used anticholinergic agents in clinical practice for the management of detrusor hyperreflexia secondary to neurogenic bladder dysfunction and is often used in the setting of Parkinson's disease. We present a rare instance of oxybutynin-induced heatstroke in an elderly patient with Parkinson's disease.

Extreme Weather and Climate Change: Population Health and Health System Implications

Extreme weather and climate events, such as heat waves, cyclones, and floods, are an expression of climate variability. These events and events influenced by climate change, such as wildfires, continue to cause significant human morbidity and mortality and adversely affect mental health and well-being. Although adverse health impacts from extreme events declined over the past few decades, climate change and more people moving into harm's way could alter this trend. Long-term changes to Earth's energy balance are increasing the frequency and intensity of many extreme events and the probability of compound events, with trends projected to accelerate under certain greenhouse gas emissions scenarios. While most of these events cannot be completely avoided, many of the health risks could be prevented through building climate-resilient health systems with improved risk reduction, preparation, response, and recovery. Conducting vulnerability and adaptation assessments and developing health system adaptation plans can identify priority actions to effectively reduce risks, such as disaster risk management and more resilient infrastructure. The risks are urgent, so action is needed now.

Use of multiple anticholinergic medications can predispose patients to severe non-exertional hyperthermia

We present a case of a 64-year-old woman who developed severe non-exertional hyperthermia (NEHT) due to excessive anticholinergic effects from her psychiatric medications. The patient was found unresponsive in a non-air-conditioned room where the outside temperature was over 33°C. She presented with altered mental status, hypotension and an oral temperature of 42°C. Drug–drug interactions from her home medications for depression, bipolar disorder and seizures (amitriptyline, cyclobenzaprine, benztropine, topiramate, clonazepam, trazodone) were suspected. Blood cultures grew Staphylococcus hominis. The patient quickly returned to baseline with supportive care in the intensive care unit. She was treated for the Staph hominis bacteraemia with a 7-day course of vancomycin. Due to her quick recovery and lack of neurological findings, severe NEHT with associated bacteraemia was determined to have caused her presenting symptoms. This patient’s multiple anticholinergic medications increased her susceptibility to develop NEHT by inhibited sweating, this patient’s natural cooling mechanism.

Climate Change and the Practice of Medicine: Essentials for Resident Education

Despite calls for including content on climate change and its effect on health in curricula across the spectrum of medical education, no widely used resource exists to guide residency training programs in this effort. This lack of resources poses challenges for training program leaders seeking to incorporate evidence-based climate and health content into their curricula. Climate change increases risks of heat-related illness, infections, asthma, mental health disorders, poor perinatal outcomes, adverse experiences from trauma and displacement, and other harms. More numerous and increasingly dangerous natural disasters caused by climate change impair delivery of care by disrupting supply chains and compromising power supplies. Graduating trainees face a knowledge gap in understanding, managing, and mitigating these many-faceted consequences of climate change, which-expected to intensify in coming decades-will influence both the health of their patients and the health care they deliver. In this article, the authors propose a framework of climate change and health educational content for residents, including how climate change (1) harms health, (2) necessitates adaptation in clinical practice, and (3) undermines health care delivery. The authors propose not only learning objectives linked to the Accreditation Council for Graduate Medical Education core competencies for resident education but also learning formats and assessment strategies in each content area. They also present opportunities for implementation of climate and health education in residency training programs. Including this content in residency education will better prepare doctors to deliver anticipatory guidance to at-risk patients, manage those experiencing climate-related health effects, and reduce care disruptions during climate-driven extreme weather events.

Prevalence of autonomic nervous system dysfunction in complex regional pain syndrome

BACKGROUND

We aimed to investigate the prevalence of dysautonomia in complex regional pain syndrome (CRPS) via the combined autonomic nervous system (ANS) function tests, including the deep breathing test (DBT), orthostatic test (OST) and sympathetic skin response (SSR).

METHOD

We retrospectively examined 263 patients who underwent the combined ANS tests to evaluate CRPS between August 2013 and December 2016. Based on the Budapest clinical criteria, patients were stratified into confirmed-CRPS or suspected-CRPS groups. We performed binary logistic regression analysis using the inverse probability of treatment weighting to investigate the association between the tests and CRPS. Sensitivity and specificity were calculated to assess the diagnostic performance of the ANS tests for CRPS. We compared the results of these tests between the outcomes of sympathetic nerve blocks (SNBs).

RESULTS

Among 247 patients, finally included in this study, 199 patients (80.6%) were diagnosed with CRPS. Abnormal results of overall or each ANS function test showed significant associations with CRPS, excluding OST (overall abnormality: OR 2.44, 95% CI 1.51 to 3.95; p<0.001; DBT: OR 2.57, 95% CI 1.23 to 5.38, p=0.013; OST: OR 1.88, 95% CI 0.92 to 3.84, p=0.085; SSR: OR 2.71, 95% CI 1.38 to 5.32, p=0.004). However, their prevalence in CRPS and their sensitivities for CRPS were low (overall abnormality: 26.1%; each test: <15%). No significant association existed between dysautonomia and SNB outcomes.

CONCLUSION

Dysautonomia, as evaluated using the combined ANS tests, were observed in a small portion of patients with CRPS. The diagnostic performances of these tests for CRPS were inadequate for clinical purposes.

Effect of Meperidine on Equine Blood Histamine, Tryptase, and Immunoglobulin-E Concentrations

Objectives: To evaluate changes in immunological parameters following subcutaneous (SC) and intramuscular (IM) administration of meperidine in horses through quantitative analysis of plasma tryptase, histamine, and IgE levels.

Methods: Six adult horses were enrolled in a prospective randomized crossover design. Horses were administered one treatment per day, with a seven day washout period: (a) meperidine 1 mg/kg IM, saline 6 mL SC; (b) saline 6 mL IM, meperidine 1 mg/kg SC; (c) saline 6 mL SC, saline 6 mL IM. Blood samples were obtained for plasmatic histamine (baseline, 5, 10, 15, 30, and 60 min) via LC-MS/MS and plasmatic tryptase (baseline, 15, 30, 60, 120, and 240 min) quantification with enzyme-linked immunoabsorbent assays. Serum immunoglobulin E (IgE) concentrations prior to any meperidine treatment and 7–14 days following the first meperidine treatment were evaluated with enzyme-linked immunoabsorbent assays. Histamine and tryptase concentrations were evaluated with a mixed-effect analysis of variance. The levels of IgE at baseline (before the administration of the first dose of meperidine) were compared with the IgE values at 60 min following the second meperidine administration with the Paired t test. Biopsies of localized injection site reactions from subcutaneous meperidine administration were collected from two horses.

Results: No statistically significant elevations from baseline in histamine (p = 0.595), tryptase (p = 0.836), or IgE (p = 0.844) were found in any of the horses in this study. There were no differences between treatment groups. Administration of SC meperidine caused a localized vasculitis and thrombosis with regional edema and hemorrhage.

Conclusion: No evidence of anaphylactoid or anaphylactic type reactions occurred following IM or SC meperidine administration.

Electrodiagnostic assessment of the autonomic nervous system: A consensus statement endorsed by the American Autonomic Society, American Academy of Neurology, and the International Federation of Clinical Neurophysiology

Evaluation of disorders of the autonomic nervous system is both an art and a science, calling upon the physician's most astute clinical skills as well as knowledge of autonomic neurology and physiology. Over the last three decades, the development of noninvasive clinical tests that assess the function of autonomic nerves, the validation and standardization of these tests, and the growth of a large body of literature characterizing test results in patients with autonomic disorders have equipped clinical practice further with a valuable set of objective tools to assist diagnosis and prognosis. This review, based on current evidence, outlines an international expert consensus set of recommendations to guide clinical electrodiagnostic autonomic testing. Grading and localization of autonomic deficits incorporates scores from sympathetic cardiovascular adrenergic, parasympathetic cardiovagal, and sudomotor testing, as no single test alone is sufficient to diagnose the degree or distribution of autonomic failure. The composite autonomic severity score (CASS) is a useful score of autonomic failure that is normalized for age and gender. Valid indications for autonomic testing include generalized autonomic failure, regional or selective system syndromes of autonomic impairment, peripheral autonomic neuropathy and ganglionopathy, small fiber neuropathy, orthostatic hypotension, orthostatic intolerance, syncope, neurodegenerative disorders, autonomic hyperactivity, and anhidrosis.

Electric fans: A potential stay-at-home cooling strategy during the COVID-19 pandemic this summer?

Current public health guidance designed to protect individuals against extreme heat and the ongoing COVID-19 pandemic is seemingly discordant, yet during the northern hemisphere summer, we are faced with the imminent threat of their simultaneous existence. Here we examine the environmental limits of electric fan-use in the context of the United States summer as a potential stay-at-home cooling strategy that aligns with existing efforts to mitigate the spread of SARS-COV-2.

Autonomic History, Examination, and Laboratory Evaluation

PURPOSE OF REVIEW

Autonomic disorders offer a fascinating view of the complexity of the nervous system. Their impact on human health ranges from benign to severe. Deciphering autonomic symptoms and signs draws on the cognitive skills and personal interest in the plight of patients that first attracted many physicians to the field of neurology. This article provides tools to sharpen those skills.

RECENT FINDINGS

Autonomic neuroscience and accumulated clinical knowledge have led to the categorization of autonomic disorders into specific syndromes that can be identified on the basis of clinical phenotypes and physiologic responses to standardized stimuli in the autonomic laboratory. A key development has been the ability to distinguish neurogenic orthostatic hypotension from other causes of hypotension. Quantification of sudomotor responses has proven valuable in the diagnosis of thermoregulatory disorders and small fiber neuropathies such as those related to diabetes mellitus. Increasing attention has focused on autonomic failure as a defining feature of neurodegenerative α-synucleinopathies, especially multiple system atrophy. As awareness of autonomic disorders has increased, the once obscure term dysautonomia has entered into common parlance.

SUMMARY

With appropriate knowledge and experience, neurologists can diagnose autonomic dysfunction accurately and with confidence. The opportunity to play an important role in caring for patients with autonomic disorders is worth the effort.

Sweating Disorders

PURPOSE OF REVIEW

This article reviews disorders of sweating, including hyperhidrosis and anhidrosis due to central or peripheral autonomic nervous system causes.

RECENT FINDINGS

Disorders of thermoregulation and sweating may manifest with hyperhidrosis or hypohidrosis/anhidrosis. Primary disorders of hyperhidrosis may significantly impact quality of life yet tend to be benign. Many sweating disorders present with compensatory hyperhidrosis due to areas of anhidrosis. Anhidrosis may occur due to either central or peripheral damage to the autonomic nervous system. The thermoregulatory control of sweating involves central pathways from the hypothalamus to the brainstem and then spinal cord as well as projections to peripheral structures, including the sympathetic chain ganglia, peripheral nerves, and eccrine sweat glands. Disruption at any point of this pathway may lead to impaired sweating. Characterization of sweating dysfunction helps localize different autonomic disorders to guide diagnosis and may allow for evaluation of treatment effect.

SUMMARY

Sweating dysfunction manifests in myriad ways, including essential hyperhidrosis, complete anhidrosis with heat intolerance, and compensatory hyperhidrosis due to anhidrosis, and often indicates involvement of underlying central or peripheral autonomic dysfunction.

Simplicity lacks robustness when projecting heat-health outcomes in a changing climate

Extreme heat adversely affects human health, productivity, and well-being, with more frequent and intense heatwaves projected to increase exposures. However, current risk projections oversimplify critical inter-individual factors of human thermoregulation, resulting in unreliable and unrealistic estimates of future adverse health outcomes.

Global warming, heat-related illnesses, and the dermatologist

Global warming, provoked by the greenhouse effect of high levels of atmospheric gases (most notably carbon dioxide and methane), directly threatens human health and survival. Individuals vary in their capacity to tolerate episodes of extreme heat. Because skin is the organ tasked with heat dissipation, it is important for dermatologists to be versed in the physiology of cutaneous heat dissipation and cognizant of clinical settings in which the skin’s thermoregulatory responses may be impaired. When the external temperature is lower than that of the skin, the skin releases internal heat through direct thermal exchange with the environment, a process that is aided by an expansion of cutaneous blood flow and eccrine sweating. Cooling through the evaporation of sweat is effective even when the external temperature exceeds that of skin. Many factors, including environmental and physiological (e.g., age and sex), and pathological (e.g., preexisting illnesses, disorders of eccrine function, and medications) considerations, affect the skin’s capacity to thermoregulate. Identification of individuals at increased risk for heat-related morbidity and mortality will become increasingly important in the care of patients.

Sudomotor Dysfunction

Disorders of sudomotor function are common and diverse in their presentations. Hyperhidrosis or hypohidrosis in generalized or regional neuroanatomical patterns can provide clues to neurologic localization and inform neurologic diagnosis. Conditions that impair sudomotor function include small fiber peripheral neuropathy, sudomotor neuropathy, myelopathy, α-synucleinopathies, autoimmune autonomic ganglionopathy, antibody-mediated hyperexcitability syndromes, and a host of medications. Particularly relevant to neurologic practice is the detection of postganglionic sudomotor deficits as a diagnostic marker of small fiber neuropathies. Extensive anhidrosis is important to recognize, as it not only correlates with symptoms of heat intolerance but may also place the patient at risk for heat stroke when under conditions of heat stress. Methods for assessing sudomotor dysfunction include the thermoregulatory sweat test, the quantitative sudomotor axon reflex test, silicone impressions, and the sympathetic skin response.

Clinical practice guideline for primary care providers in the management of antidepressant-induced hyperhidrosis: A quality improvement project

BACKGROUND

Antidepressant-induced excessive sweating (ADIES) is a side effect that occurs in approximately 22% of patients taking antidepressant medications and can negatively affect patient medication adherence.

LOCAL PROBLEM

Primary care providers may not have adequate knowledge of ADIES management. The aims of this project were to increase primary care provider's overall perceived knowledge related to ADIES, improve confidence in the management of ADIES, and gather input on the perceived usefulness of the initial clinical practice guideline (CPG) for ADIES management.

METHODS

This quality improvement (QI) project consisted of two phases. Phase 1 included the development of a CPG for the pharmacologic management of ADIES based on processes recommended by the Institute of Medicine.

INTERVENTIONS

Phase 2 of the project consisted of a pretest-posttest design pilot of the guideline via a "Lunch and Learn" educational session at a Federally Qualified Health Care Center located in the Northern California.

RESULTS

The results indicated that after exposure to the CPG and participation in the educational program about the guideline, there was an overall significant improvement in provider knowledge and confidence about identification and management of ADIES in their practice.

CONCLUSIONS

Although small in scope, this QI project provides important avenues for further implementation and dissemination of the guideline to manage ADIES. The potential for improved patient care and medication adherence support the usefulness of the implementation of this guideline in other locations.

Sudor Anglicus: an epidemic targeting the autonomic nervous system

Renaissance England witnessed a series of brief epidemics of a rapid and often fatal illness, the predominant feature of which was a disturbance of the autonomic nervous system. Profuse sweating was both an emblematic and ominous sign of this Sudor Anglicus. Its story is medically fascinating as well as historically noteworthy. Possible sites of pathological involvement include the hypothalamus, serotonergic neurons in the brainstem or spinal cord, autonomic ganglia, peripheral sympathetic nerves, neuroeffector junctions, or eccrine glands. Of candidate etiologic agents, a virus is most likely, given the seasonal variation, geographic clustering, and pattern of spread of the epidemics. Hantaviruses, enteroviruses, influenza, and others provide clinical comparisons, but a definitive match with known viruses has remained elusive.

Analysis of quantitative sudomotor axon reflex test patterns in patients with complex regional pain syndrome diagnosed using the Budapest criteria

BACKGROUND

Although the quantitative sensory axon reflex test (QSART) is used to evaluate sudomotor dysfunction in the diagnosis of complex regional pain syndrome (CRPS), its validity remains controversial. This study investigated the diagnostic performance of the QSART for CRPS and assessed associations between results of the QSART and other clinical variables.

METHODS

We examined the electronic medical records of 196 consecutive patients who underwent the QSART with a suspected diagnosis of CRPS, during the period from January 2013 to December 2015. To assess the diagnostic performance of the QSART for CRPS based on the Budapest research criteria, we calculated sensitivity, specificity, positive likelihood ratio and negative likelihood ratio. Furthermore, we performed binary logistic regression analyses to investigate the relationships between QSART results and other clinical variables.

RESULTS

The sensitivity and specificity of the QSART for diagnosing CRPS were 67.6% and 40.6%, respectively. The OR for diagnosing CRPS using the QSART was not statistically significant (1.43; 95% CI 0.65 to 3.14; p=0.376), whereas it was for distinguishing CRPS types I and II (4.11; 95% CI 1.34 to 12.57; p=0.013). In multivariable analysis, there were no correlations between the results of the QSART and other variables, except hypertension (OR=0.34; 95% CI 0.13 to 0.91; p=0.032).

CONCLUSION

The QSART showed low diagnostic value as a screening or a confirmatory test for CRPS according to the Budapest research criteria. CRPS type II was more likely than CRPS type I to result in abnormal QSART results.

Health Risks and Interventions in Exertional Heat Stress

BACKGROUND

With climate change, heat waves are expected to become more frequent in the near future. Already, on average more than 25 000 "heat deaths" are estimated to occur in Europe every year. However, heat stress and heat illnesses arise not just when ambient temperatures are high. Physical exertion increases heat production within the organism many times over; if not enough heat is lost, there is a risk of exertional heat stress. This review article discusses contributing factors, at-risk groups, and the diagnosis and treatment of heat illnesses.

METHODS

A selective literature search was carried out on PubMed. Current guidelines and expert recommendations were also included.

RESULTS

Apart from muscular heat production (>70% of converted energy), there are other factors that singly or in combination can give rise to heat stress: clothing, climate/acclimatization, and individual factors. Through its insulating properties, clothing reduces the evaporation of sweat (the most effective physiological cooling mechanism). A sudden heat wave, or changing the climate zone (as with air travel), increases the risk of a heat-related health event. Overweight, low fitness level, acute infections, illness, dehydration, and other factors also reduce heat tolerance. In addition to children, older people are particularly at risk because of their reduced physiological adaptability, (multi-)morbidity, and intake of prescription drugs. A heat illness can progress suddenly to life-threatening heat stroke. Successful treatment depends on rapid diagnosis and cooling the body down as quickly as possible. The aim is to reduce core body temperature to <40 °C within 30 minutes.

CONCLUSION

Immediately effective cooling interventions are the only causal treatment for heat stroke. Time once lost cannot be made up. Prevention (acclimatization, reduced exposure, etc.) and terminating the heat stress in good time (e.g., stopping work) are better than any cure.

[Epidemiology and prevention of heat-related adverse health effects on elderly people]

Heat waves increase the morbidity and mortality in Germany, particularly of older patients in need of care. Due to climate change the number of heat waves in Germany will increase threefold by the end of the century. In addition, the proportion of patients at risk will grow due to demographic change. Therefore, the Government and the Federal States have developed recommendations for heat action plans, in which the medical profession should also participate in the prevention of heat-related damage to health. Physicians and their team should first become acquainted with the topic. In addition, they should inform patients at risk and their relatives of the risks and preventive measures. In the summer a critical check of drugs is also needed because medications impair cooling mechanisms in heat waves, the pharmacokinetics can change and unwanted side effects of drugs occur more frequently. Lastly, due to their central position in the healthcare system, physicians should participate in the coordination of a good nursing care and intensification of social contacts during heat waves.

Physiology of sweat gland function: The roles of sweating and sweat composition in human health

The purpose of this comprehensive review is to: 1) review the physiology of sweat gland function and mechanisms determining the amount and composition of sweat excreted onto the skin surface; 2) provide an overview of the well-established thermoregulatory functions and adaptive responses of the sweat gland; and 3) discuss the state of evidence for potential non-thermoregulatory roles of sweat in the maintenance and/or perturbation of human health. The role of sweating to eliminate waste products and toxicants seems to be minor compared with other avenues of excretion via the kidneys and gastrointestinal tract; as eccrine glands do not adapt to increase excretion rates either via concentrating sweat or increasing overall sweating rate. Studies suggesting a larger role of sweat glands in clearing waste products or toxicants from the body may be an artifact of methodological issues rather than evidence for selective transport. Furthermore, unlike the renal system, it seems that sweat glands do not conserve water loss or concentrate sweat fluid through vasopressin-mediated water reabsorption. Individuals with high NaCl concentrations in sweat (e.g. cystic fibrosis) have an increased risk of NaCl imbalances during prolonged periods of heavy sweating; however, sweat-induced deficiencies appear to be of minimal risk for trace minerals and vitamins. Additional research is needed to elucidate the potential role of eccrine sweating in skin hydration and microbial defense. Finally, the utility of sweat composition as a biomarker for human physiology is currently limited; as more research is needed to determine potential relations between sweat and blood solute concentrations.

Modulation of neurological pathways by Salvia officinalis and its dependence on manufacturing process and plant parts used

Background

Salvia officinalis has been used successfully for the treatment of hot flushes and excessive sweating during menopause. However, modes of actions have not been elucidated conclusively. We explored its pharmacology beyond any hormonal activity with a focus on neurologic impulse transmission.

Methods

A hydroalcoholic, thujone-free extract from freshly harvested Salvia officinalis leaves (A.Vogel Menosan®) was investigated in an acetylcholinesterase enzyme assay and several receptor binding assays (adrenergic alpha 2A, GABA (benzodiazepine site), GABA_B; muscarinic M3, μ-opioid, serotonin 5-HT_1A, serotonin 5-HT_2B, serotonin 5-HT_2C and serotonin transporter). The influence of the manufacturing process on additional extracts from different fresh or dry plant parts was studied.

Results

The Salvia officinalis extract replaced 50% of specific ligand binding to GABA_A and GABA_B receptors at an inhibitory concentration (IC₅₀) of 89 and 229 μg/ml, respectively. Strong binding affinity was observed for the adrenergic α_2A receptor, μ-opioid receptors, muscarinic M3 receptors, and serotonin 5-HT_1A receptors, with IC₅₀ values of 15 μg/ml, 20 μg/ml, 25 μg/ml and 19 μg/ml, respectively. Moderate interference with 5-HT_2B, 5-HT_2C receptors, and the human serotonin transporter was found, all with IC₅₀ values above 32 μg/ml. Receptor binding data of Salvia extract were confirmed in native female hypothalamic tissue from two women (51 and 37 years old).

Use of freshly harvested Salvia leaves resulted in 2- to 4-fold higher activity/lower IC₅₀ values compared to extracts from dried plants or stipes.

Conclusion

Our results suggest potent modulation of neuro-receptors and of serotonin transporters as mode of action for Salvia officinalis alcoholic extract, which may normalize thermoregulation and possibly also mental impairment during menopause.

Apathy alters emotional arousal in chronic schizophrenia

Background

Within the heterogeneity of schizophrenia, apathy constitutes an independent cluster of negative symptoms associated with poor outcomes. Attempts to identify an emotional deficit in patients who have schizophrenia with negative symptoms have yielded mixed results, and studies that focus on the relationship between apathy and emotional disorders are lacking.

Methods

We set out to remedy this shortcoming using a validated battery of film excerpts to induce positive and negative emotions in patients with chronic schizophrenia with (n = 20) or without (n = 20) apathy, and in controls (n = 20) comparable for age, sex and socioeconomic status. We assessed emotions using an innovative but validated technique to evaluate tonic and phasic electrodermal activity and subjective feelings using a standardized visual analogue scale.

Results

Using a qualitative measure of apathy, we did not find a specific decrease in tonic activity during the induction of positive emotions. However, we did observe that patients with apathy showed reduced tonic activity independent of valence (i.e., for both positive and negative emotions) compared with controls and patients without apathy. Moreover, the quantitative measure of apathy (Apathy Evaluation Scale) was the only significant factor, explaining 24% of the variance in tonic activity during induction of positive emotions after controlling for confounding factors.

Limitations

Electrodermal activity was the only physiologic measure we acquired. We induced several emotions sequentially that might have overlapped with each other, but we added an emotional “washout” period and randomized the order of each film excerpt to limit this possibility.

Conclusion

Taken together, these results suggest that apathy in schizophrenia could impair tonic activity during positive emotions. Treatments aimed at enhancing positive emotions may help alleviate apathy in schizophrenia.

Sweating Rate and Sweat Sodium Concentration in Athletes: A Review of Methodology and Intra/Interindividual Variability

Athletes lose water and electrolytes as a consequence of thermoregulatory sweating during exercise and it is well known that the rate and composition of sweat loss can vary considerably within and among individuals. Many scientists and practitioners conduct sweat tests to determine sweat water and electrolyte losses of athletes during practice and competition. The information gleaned from sweat testing is often used to guide personalized fluid and electrolyte replacement recommendations for athletes; however, unstandardized methodological practices and challenging field conditions can produce inconsistent/inaccurate results. The primary objective of this paper is to provide a review of the literature regarding the effect of laboratory and field sweat-testing methodological variations on sweating rate (SR) and sweat composition (primarily sodium concentration [Na⁺]). The simplest and most accurate method to assess whole-body SR is via changes in body mass during exercise; however, potential confounding factors to consider are non-sweat sources of mass change and trapped sweat in clothing. In addition, variability in sweat [Na⁺] can result from differences in the type of collection system used (whole body or localized), the timing/duration of sweat collection, skin cleaning procedure, sample storage/handling, and analytical technique. Another aim of this paper is to briefly review factors that may impact intra/interindividual variability in SR and sweat [Na⁺] during exercise, including exercise intensity, environmental conditions, heat acclimation, aerobic capacity, body size/composition, wearing of protective equipment, sex, maturation, aging, diet, and/or hydration status. In summary, sweat testing can be a useful tool to estimate athletes’ SR and sweat Na⁺ loss to help guide fluid/electrolyte replacement strategies, provided that data are collected, analyzed, and interpreted appropriately.

Investigation on aetiological factors in patients with hyperhidrosis

BACKGROUND

Hyperhidrosis is a condition where the amount of sweat released to skin surface increases due to the over-active eccrine sweat glands. Hyperhidrosis causes considerable psychosocial distress in affected people. It affects the quality of life and leads to social anxiety disorders.

AIMS

No study has been conducted in our country to investigate the epidemiological, clinical, and laboratory data of patients with hyperhidrosis. In this study, we aimed to retrospectively investigate the clinical and demographic characteristics, causes of sweating and laboratory findings in patients treated for hyperhidrosis at our outpatient clinic and to compare these data with the literature data.

MATERIALS AND METHODS

A retrospective review was conducted on medical records of patients diagnosed with and treated for hyperhidrosis at outpatient clinic between 2014 and 2017. Adults aged over 18 years were included in study. Age and gender of patients, type and localization of sweating, duration of disease, age of onset of sweating, presence of stress, fever, joint pain and comorbidity, family history, medication use, and examination results were recorded.

RESULTS

Records of a total of 70 patients consisting of 30 men and 40 women with hyperhidrosis were examined. Overall mean age was 37.1 years. Mean age was 41 years in women and 32 years in men. Most frequent forms were palmoplantar and axillary hyperhidrosis for primary hyperhidrosis (primary HH), and head-neck and generalized hyperhidrosis for secondary hyperhidrosis (secondary HH). Most common comorbidities were diabetes mellitus, thyroid disease, non-specific joint and bone pain, cardiovascular disease, and neuropsychiatric disease. Cases with secondary HH had a history of drug use (antithyroid drugs, nonsteroidal anti-inflammatory drugs, antidiabetic agents, antidepressants, and antihypertensives).

CONCLUSION

This is the first study that investigated the characteristics of patients with primary and secondary HH in our country. These characteristics can help determine the cause and apply treatment for hyperhidrosis by an appropriate examination and approach.

Meta-analysis: Risk of hyperhidrosis with second-generation antidepressants

BACKGROUND

Our goal was to quantify the risk of hyperhidrosis associated with commonly used antidepressant agents and examine the impact of medication class, pharmacodynamics, and dose on risk of hyperhidrosis.

METHODS

We conducted a PubMed search to identify all double-blind, randomized, placebo-controlled trials examining the efficacy of second-generation antidepressant medications in the treatment of adults with a depressive disorder, anxiety disorders, or obsessive-compulsive disorder. We used a random-effects meta-analysis to examine the pooled risk ratio of hyperhidrosis reported as a side effect in adults treated with second-generation antidepressants compared to placebo. We used stratified subgroup analysis and metaregression to examine the effects of medication type, class, dosage, indication, and receptor affinity profile on the measured risk of hyperhidrosis.

RESULTS

We identified 76 trials involving 28,544 subjects. There was no significant difference in the risk of hyperhidrosis between serotonin-norepinephrine reuptake inhibitors (SNRI) [risk ratio (RR) = 3.17, 95% CI: 2.63-3.82] and selective serotonin reuptake inhibitors (SSRI) (RR = 2.93, 95% CI: 2.46-3.47) medications compared to placebo. All antidepressant medications were associated with a significantly increased risk of hyperhidrosis except fluvoxamine (RR = 0.56, 95% CI: 0.12-2.53), bupropion (RR = 1.23, 95% CI: 0.57-2.67), and vortioxetine (RR = 1.35, 95% CI: 0.79-2.33). The dose of SSRI/SNRI medications was not significantly associated with the risk of hyperhidrosis. Increased risk of hyperhidrosis was associated with increased affinity of SSRI/SNRI medications to the dopamine transporter.

CONCLUSION

Risk of hyperhidrosis was significantly increased with most antidepressant medications but was associated with dopamine transporter affinity.