Acute fasting reduces tolerance to progressive central hypovolemia in humans.

Potential health benefits of an acute fast include reductions in blood pressure and increases in vagal cardiac control. These purported health benefits could put fasted humans at risk for cardiovascular collapse when exposed to central hypovolemia. The purpose of this study was to test the hypothesis that an acute 24-h fast (vs. 3-h postprandial) would reduce tolerance to central hypovolemia induced via lower body negative pressure (LBNP). We measured blood ketones (ß-OHB) to confirm a successful fast (n = 18). We recorded the electrocardiogram (ECG), beat-to-beat arterial pressure, muscle sympathetic nerve activity (MSNA; n = 7), middle cerebral artery blood velocity (MCAv), and forearm blood flow. Following a 5-min baseline, LBNP was increased by 15 mmHg until -60 mmHg and then increased by 10 mmHg in a stepwise manner until onset of presyncope. Each LBNP stage lasted 5-min. Data are expressed as means ± SE ß-OHB increased (ß-OHB; 0.12 ± 0.04 fed vs. 0.47 ± 0.11, P < 0.01 mmol/L fast). Tolerance to central hypovolemia was decreased by ∼10% in the fasted condition measured via total duration of negative pressure (1,370 [Formula: see text] 89 fed vs. 1,229 ± 94 s fast, P = 0.04), and was negatively associated with fasting blood ketones (R = -0.542, P = 0.02). During LBNP, heart rate and MSNA increased similarly, but in the fasted condition forearm vascular resistance was significantly reduced. Our results suggest that acute fasting reduces tolerance to central hypovolemia by blunting increases in peripheral resistance, indicating that prolonged fasting may hinder an individual's ability to compensate to a loss of blood volume.NEW & NOTEWORTHY An acute 24 h fasting reduces tolerance to central hypovolemia, and tolerance is negatively associated with blood ketone levels. Compared with a fed condition (3-h postprandial), fasted participants exhibited blunted peripheral vasoconstriction and greater reductions in stroke volume during stepwise lower body negative pressure. These findings suggest that a prolonged fast may lead to quicker decompensation during central hypovolemia.

Core body temperature changes before sleep are associated with nocturnal heart rate variability.

Core body temperature (CBT) reductions occur before and during the sleep period, with the extent of presleep reductions corresponding to sleep onset and quality. Presleep reductions in CBT coincide with increased cardiac parasympathetic activity measured via heart rate variability (HRV), and while this appears to persist into the sleep period, individual differences in presleep CBT decline and nocturnal HRV remain unexplored. The purpose of the current study was to assess the relationship between individual differences in presleep CBT reductions and nocturnal heart rate (HR) and HRV in a population of 15 objectively poor sleeping adults [10 males, 5 females; age, 33 ± 4 yr; body mass index (BMI) 27 ± 1 kg/m2] with the hypothesis that blunted CBT rate of decline would be associated with elevated HR and reduced nocturnal HRV. Following an adaptation night, all participants underwent an overnight, in-laboratory sleep study with simultaneous recording of polysomnographic sleep including electrocardiography (ECG) and CBT recording. Correlations between CBT rate of change before sleep and nocturnal HRV were assessed. Blunted rate of CBT decline was significantly associated with increased heart rate (HR) in stage 2 (N2; R = 0.754, P = 0.001), stage 3 (N3; R = 0.748, P = 0.001), and rapid-eye movement (REM; R = 0.735, P = 0.002). Similarly, blunted rate of CBT decline before sleep was associated with reduced HRV across sleep stages. These findings indicate a relationship between individual differences in presleep thermoregulatory processes and nocturnal cardiac autonomic function in poor sleeping adults.NEW & NOTEWORTHY Core body temperature (CBT) reductions before sleep onset coincide with increases in heart rate variability (HRV) that persist throughout the sleep period. However, the relationship between individual differences in the efficiency of presleep core temperature regulation and nocturnal heart rate variability remains equivocal. The present study reports an association between the magnitude of presleep core body temperature changes and nocturnal parasympathetic activity, highlighting overlap between thermoregulatory processes before sleep and nocturnal cardiac autonomic function.

Daily cannabis use is associated with sleep duration differentially across ages.

OBJECTIVE: To assess the relationship between frequency of cannabis use and sleep duration across age in a large US population (235,667 people). METHODS: Multinomial logistic regression was used to evaluate the association between the frequency of cannabis use and sleep duration using cross sectional data from the 2016-2018 Behavioral Risk Factor Surveillance System. RESULTS: When adjusted for sociodemographic factors, health related variables, and stratified by age we found that young adults (18-44 years) who reported daily-use (≥16 uses a month) had an increased risk ratio (RR [95% CI]) for either short or long sleep (1.22 [1.06-1.40] and 1.52 [1.07-2.16]); midlife adults (45-64 years) who reported daily-use had an increased prevalence of long sleep (1.71 [1.03-2.82]); and older adults (≥65 years) who reported daily-use had an increased prevalence of short sleep (1.61 [1.05-2.49]). CONCLUSIONS: Compared to those who reported no cannabis use, individuals who reported daily cannabis use demonstrated a greater prevalence for either short or long sleep duration.

Traditional knowledge of medicinal mushrooms and lichens of Yuman peoples in Northern Mexico.

BACKGROUND: Mushrooms and lichens are natural therapeutic resources whose millenary importance persists in indigenous and mestizo communities of Mexico. However, in this regard, in the northern part of the country there are few ethnobiological explorations. This study investigates the local knowledge of medicinal mushrooms and lichens used by Yuman peoples, whose native speakers are in imminent danger of extinction along with their biocultural heritage due to changes in their traditional primary activities and the usurpation of their ancestral lands. METHODS: Ethnographic techniques in the field and standard lichenological and mycological methods in the laboratory were used. RESULTS: Information was obtained on the medicinal use of 20 species, of which six are lichens of the genus Xanthoparmelia and 14 are non-lichenized fungi, mainly gasteroids. The latter are primarily used to treat skin lesions, while lichens are used in heart, urinary, and gastrointestinal diseases. The transmission of this local knowledge to future generations is discussed, as well as the intercultural cognitive convergence about the uses of medicinal mushrooms and lichens. CONCLUSIONS: The Yuman peoples preserve knowledge, practices and beliefs around mushrooms and lichens. Although increasingly less used, they still form part of their culinary and traditional medicine; even some are also used as ludic and ornamental purposes, and as trail markers. Beyond the pragmatic importance of these organisms, traditional knowledge about them is an essential part of the cultural identity that the Yuman peoples strive to preserve.

Influence of an acute fast on ambulatory blood pressure and autonomic cardiovascular control.

Evidence suggests that intermittent fasting improves cardiovascular health by reducing arterial blood pressure, but contributing mechanisms are unclear. The purpose of this study was to determine the influence of an acute fast on hemodynamics, muscle sympathetic nerve activity (MSNA), and autonomic control at rest and during an arterial pressure challenge. Twenty-five young normotensive volunteers were tested twice, in the fed and fasted (24 h) states (randomized). Twenty-four hour ambulatory blood pressure was measured before an autonomic function test, which consisted of a 10-min period of controlled breathing (CB) at 0.25 Hz followed by 3, 15-s Valsalva maneuvers (VMs). We recorded the ECG, beat-to-beat arterial pressure, and MSNA throughout the autonomic test. Vagal-cardiac modulation via heart rate variability (HRV) was assessed in both time and frequency domains, cardiovagal baroreflex sensitivity (cvBRS) was assessed with linear regression, and stroke volume was estimated from pulse contour. All fed versus fasted comparisons presented are different at P < 0.05. Fasting reduced ambulatory mean arterial pressure (81 ± 1 vs. 78 ± 1 mmHg) and heart rate (69 ± 2 vs. 65 ± 2 beats/min). CB revealed enhanced HRV through increased R-R intervals (992 ± 30 vs. 1,059 ± 37 ms) and normalized high frequency (HFnu) R-R interval spectral power (55 ± 3 vs. 62 ± 3%). Estimated stroke volume was higher after fasting (by 13%) as was cvBRS (20 ± 2 vs. 26 ± 5 ms/mmHg) and cvBRS during phase IV of the VM (9 ± 1 vs. 12 ± 1 ms/mmHg). MSNA (n = 12) did not change (16 ± 11 vs. 15 ± 8 bursts/min; P = 0.18). Our results show that acute fasting is consistent with improved cardiovascular health: such improvements are driven by reduced ambulatory arterial pressure and enhanced vagal-cardiac modulation.

Controlled breathing and autonomic rhythms: Influence of auditory versus visual cues.

We compared standard metrics of autonomic control in 20 humans (10 female) during spontaneous and controlled breathing. Subjects controlled breathing at 0.25 Hz following a metronome (auditory) or scrolling waveforms (visual). Respiratory rates and heart rates were lower during spontaneous breathing compared with auditory and visual. One heart rate variability metric was higher during visual compared with spontaneous breathing, but baroreflex sensitivity and muscle sympathetic nerve activity were not affected by breathing cues. A majority of subjects (86%) perceived that breathing to auditory cues was more difficult compared with visual cues, but this elevated perceived stress did not manifest physiologically.

Acute effects of electronic cigarettes on arterial pressure and peripheral sympathetic activity in young nonsmokers.

Electronic cigarettes (e-cigarettes) are marketed as an alternative to smoking for those who want to decrease the health risks of tobacco. Tobacco cigarettes increase heart rate (HR) and arterial pressure, while reducing muscle sympathetic nerve activity (MSNA) through sympathetic baroreflex inhibition. The acute effects of e-cigarettes on arterial pressure and MSNA have not been reported: our purpose was to clarify this issue. Using a randomized crossover design, participants inhaled on a JUUL e-cigarette containing nicotine (59 mg/mL) and a similar placebo e-cigarette (0 mg/mL). Experiments were separated by ∼1 mo. We recorded baseline ECG, finger arterial pressure (n = 15), and MSNA (n = 10). Subjects rested for 10 min (BASE) and then inhaled once every 30 s on an e-cigarette that contained nicotine or placebo (VAPE) for 10 min followed by a 10-min recovery (REC). Data were expressed as Δ means ± SE from BASE. Heart rate increased in the nicotine condition during VAPE and returned to BASE values in REC (5.0 ± 1.3 beats/min nicotine vs. 0.1 ± 0.8 beats/min placebo, during VAPE; P < 0.01). Mean arterial pressure increased in the nicotine condition during VAPE and remained elevated during REC (6.5 ± 1.6 mmHg nicotine vs. 2.6 ± 1 mmHg placebo, during VAPE and 4.6.0 ± 1.7 mmHg nicotine vs. 1.4 ± 1.4 mmHg placebo, during REC; P < 0.05). MSNA decreased from BASE to VAPE and did not restore during REC (-7.1 ± 1.6 bursts/min nicotine vs. 2.6 ± 2 bursts/min placebo, during VAPE and -5.8 ± 1.7 bursts/min nicotine vs. 0.5 ± 1.4 bursts/min placebo, during REC; P < 0.05). Our results show that acute e-cigarette usage increases mean arterial pressure leading to a baroreflex-mediated inhibition of MSNA.NEW & NOTEWORTHY The JUUL e-cigarette is the most popular e-cigarette in the market. In the present study, inhaling on a JUUL e-cigarette increased mean arterial pressure and heart rate, and decreased muscle sympathetic nerve activity (MSNA). In contrast, inhaling on a placebo e-cigarette without nicotine elicited no sympathomimetic effects. Although previous tobacco cigarette studies have demonstrated increased mean arterial pressure and MSNA inhibition, ours is the first study to report similar responses while inhaling on an e-cigarette. Listen to this article's corresponding podcast at @ https://ajpheart.podbean.com/e/aerosolized-nicotine-and-cardiovascular-control/.

Compliance With Fluoxetine Use in Men With Primary Premature Ejaculation.

BACKGROUND: Premature ejaculation (PE) is a common sexual dysfunction for which selective serotonin reuptake inhibitors (SSRIs) have been used effectively for treatment. However, compliance with therapy and predictors of long-term SSRI use in the treatment of PE are not well known. AIM: To analyze our experience with drop-out rates with fluoxetine in the primary PE population and to identify predictors of continued use of this agent. METHODS: Men with primary PE constituted who used fluoxetine and had at least 12 months follow-up constituted the study population. Subjects underwent a comprehensive interview to ascertain self-reported (non-stopwatch) intravaginal ejaculatory latency time (IELT), self-rated control over ejaculation, and personal and patient-reported partner distress due to PE. Patients were treated with fluoxetine 20 mg daily, with the possibility of dose titration up or down based on efficacy and side effects. OUTCOMES: The PE parameters of interest included self-reported IELT, self-rated control over ejaculation, personal and partner distress due to PE, and medication adherence. RESULTS: 130 men were included in the study. Dropout rates at 6 and 12 months were 56% and 72%. Self-rated "poor" ejaculatory control decreased from 98%-41% (P < .01), high personal distress from 47%-11% (P < .01), and high partner distress rates from 72%-27% (P < .01). Predictors of continued use at 12 months included high partner distress, being unpartnered, and having a post-treatment IELT ≥5 minutes (P < .01). Overall side effects included headache (5%), dizziness (4%), nausea (5%), nervousness (5%), and sleepiness (8%); however, moderate to severe side effects reported included nausea (2%), sleepiness (2%), headache (2%), and dizziness (2%). CLINICAL IMPLICATIONS: Compliance with SSRIs is a well-described problem in the depression literature, but data are sparse regarding continued use of SSRIs in the treatment of PE. STRENGTHS AND LIMITATIONS: We report on 12-month compliance with SSRIs for the treatment of PE. Our early compliance rates were more encouraging than what has been reported in the past. However, IELT was self-reported and not measured objectively, and we did not use validated patient-reported outcomes but rather self-reported ejaculatory control and distress levels, which have limitations. CONCLUSIONS: Fluoxetine is an effective agent for the treatment of PE with significant improvement realized in IELT, ejaculatory control, and distress levels for both men and their partners. Despite its efficacy, continued use of fluoxetine beyond 6 months is poor. Jenkins LC, Gonzalez J, Tal R, et al. Compliance with Fluoxetine Use in Men with Primary Premature Ejaculation. J Sex Med 2020;16:1895-1899.

A Review of Male and Female Sexual Function Following Colorectal Surgery.

INTRODUCTION: Sexual function after colorectal surgery is a largely ignored topic. In patients being treated for colon and rectal cancers, the risk of sexual dysfunction after surgery is high and is influenced by multiple factors. AIM: To examine the factors involved with sexual dysfunction after colorectal surgery and review gender-specific sexual complaints most reported on in the literature. METHODS: A comprehensive review of peer-reviewed publications on the topic was performed through a PubMed search. Key search terms and phrases included colorectal surgery, sexual dysfunction, risk factors, cancer, erectile dysfunction, dyspareunia, and counseling. MAIN OUTCOME MEASURES: The main outcome measures were gender-specific sexual complaints after colorectal surgery and risk factors involved. RESULTS: The type of excision and surgical technique strongly influences sexual dysfunction risk, where newer nerve-preserving techniques seem to be associated with better sexual outcomes in contrast to more extensive surgeries. Adjunctive radiotherapy negatively affects sexual health when combined with surgical resection. The most common postoperative sexual complaints reported by men include erectile dysfunction, ejaculatory dysfunction, and dysorgasmia, whereas for women dyspareunia and poor lubrication are common. CONCLUSIONS: Sexual morbidity after treatment for colorectal cancer is common and inadequately addressed by healthcare providers in the preoperative setting. Towe M, Huynh LM, El-Khatib F, et al. A Review of Male and Female Sexual Function Following Colorectal Surgery. Sex Med Rev 2019;7:422-429.

The Role of Pelvic Floor Muscles in Male Sexual Dysfunction and Pelvic Pain.

INTRODUCTION: Sexual function is essential to good health and well-being in men. The relationship between male sexual function, pelvic floor function, and pelvic pain is complex and only beginning to be appreciated. AIM: The objectives of the current review are to examine these complex relationships, and to demonstrate how pelvic floor physical therapy can potentially improve the treatment of various male sexual dysfunctions, including erectile dysfunction and dysfunction of ejaculation and orgasm. METHODS: Contemporary data on pelvic floor anatomy and function as they relate to the treatment of various male sexual dysfunctions were reviewed. MAIN OUTCOME MEASURES: Examination of evidence supporting the association between the male pelvic floor and erectile dysfunction, ejaculatory/orgasmic dysfunction, and chronic prostatitis/chronic pelvic pain syndrome, respectively. RESULTS: Evidence suggests a close relationship between the pelvic floor and male sexual dysfunction and a potential therapeutic benefit from pelvic floor therapy for men who suffer from these conditions. CONCLUSION: Pelvic floor physical therapy is a necessary tool in a more comprehensive bio-neuromusculoskeletal-psychosocial approach to the treatment of male sexual dysfunction and pelvic pain.

Peripheral Female Genital Arousal as Assessed by Thermography Following Topical Genital Application of Alprostadil vs Placebo Arousal Gel: A Proof-of-Principle Study Without Visual Sexual Stimulation.

INTRODUCTION: Female sexual arousal disorder is a pathophysiologic state characterized clinically by persistent or recurrent inability to attain or maintain an adequate lubrication-swelling response of sexual excitement until completion of sexual activity. Prior clinical experience with alprostadil products for men with erectile dysfunction supports its use in women with female sexual arousal disorder. AIM: To compare the effect of topical alprostadil with over-the-counter (OTC) lubricant on female genital arousal in the absence of visual sexual stimuli. METHODS: Healthy premenopausal women without sexual dysfunction were recruited from the community to participate in the study. Of 17 women who consented, 10 were enrolled and completed the trial. The mean age of subjects was 32 years (range = 27-43). Study drug or placebo was applied topically to the genitals. Continuous temperature monitoring was performed. Participants completed questionnaires assessing genital sensation, effect, intensity, and duration. MAIN OUTCOME MEASURES: Change in temperature from baseline in vestibule, clitoris and vulva. RESULTS: In all 10 subjects, topical alprostadil induced a statistically significant increase in temperature of the vestibule, clitoris, and vulva compared with the OTC lubricant. The most rapid difference in genital temperature between placebo and alprostadil was seen on the vulva, which demonstrated a significant difference at approximately 9 minutes. There was a significant difference in temperature seen for the vestibule and clitoris at 11 and 19 minutes, respectively. Sixty percent of women reported being aware or conscious of genital sensations with topical alprostadil, but not with OTC lubricant. Discordance was noted in 30% of subjects who reported being aware or conscious of genital sensations with the two treatments and 10% who reported not being aware or conscious of genital sensations with either treatment. CONCLUSION: Topical alprostadil administered to healthy premenopausal women induced statistically significant, sustained increases in genital temperatures of the vestibule, clitoris, and vulva within 20 minutes compared with OTC lubricant.

Association of healthcare barriers with prostate-specific antigen screening among African-American and Afro-Caribbean men.

OBJECTIVE: To evaluate the association between the barriers to healthcare access and prostate-specific antigen (PSA) screening practices among African-American and Afro-Caribbean men. METHODS: Stratified cluster sampling of census tracts in Brooklyn, New York yielded 533 men, aged 45-70 years. The men were classified into the following groups: U.S.-born white, U.S.-born African-American, Jamaican, and Trinidadian/Tobagonian. The subjects completed a written 6-item survey assessing the healthcare barriers. RESULTS: Overall, 27% of men reported never having had a PSA test and 28% reported that they had received annual PSA screening. On multivariate analysis, those who viewed the healthcare system as convenient were more likely to report an initial PSA test (odds ratio 1.8, P < .05). Those who perceived difficulty in accessing reliable care were less likely to ever have had a PSA test (odds ratio 0.6, P < .05). Subjects who had not had a comprehensive discussion with their physician about prostate cancer were less likely to have had an initial PSA test and more likely to have maintained annual PSA screening (odds ratio 0.3 and 1.7, respectively, P < .05). CONCLUSION: We identified 2 novel perceived barriers to prostate cancer screening: men who experience the healthcare system as inconvenient were less likely to initiate PSA testing, and those who found it difficult to obtain quality care were less likely to ever have had a PSA test. The perceived system barriers were more closely linked to PSA screening behavior than were the measures assessing perceptions of self-efficacy. Our results suggest that a broader discussion by physicians that addresses the perceptions regarding the healthcare system might enhance the understanding of, and increase the use of, prostate cancer screening among higher risk minority men.

Invasion of renal sinus fat is not an independent predictor of survival in pT3a renal cell carcinoma.

OBJECTIVE: To clarify the significance of the location of extrarenal tumour extension of renal cell carcinoma (RCC) as in the 2002 Tumour-Nodes-Metastasis classification. Renal cortical tumours with perirenal fat invasion (PFI) or sinus fat invasion (SFI) are consolidated within the pT3a grouping; tumours with SFI are close to the renal veins, lymphatics and the collecting system. This might carry a worse prognosis for disease-specific survival (DSS), but reports are limited and contradictory. PATIENTS AND METHODS: We retrospectively reviewed 1244 patients treated with nephrectomy from 1988 to 2007, to identify patients with pT3a renal tumours. They were classified as having PFI or SFI. Kaplan-Meier analysis and Cox proportional hazards regression models were used to assess predictors of survival. RESULTS: The 230 patients who met the inclusion criteria had a median follow-up of 24 months. SFI was found in 63 (27.4%) patients and was associated with a worse 5-year DSS than the 167 (72.6%) with PFI (62.5% vs 75.0%; log rank P = 0.022). On univariate analysis, diameter (hazard ratio, HR 1.1), nuclear grade (HR 4.5), margin status (HR 5.8), lymph node metastases (HR 6.4), and systemic metastases (HR 15.4) were significant for DSS. In a multivariate model, only nuclear grade (HR 3.1), margin status (HR 8.9) and systemic metastases (HR 9.8) were independent predictors. CONCLUSION: Patients with renal tumours with SFI are more likely to die from RCC than those with PFI. However, in the present patients the presence of SFI was not an independent predictor of DSS.

Barriers to the initiation and maintenance of prostate specific antigen screening in Black American and Afro-Caribbean men.

PURPOSE: Black American and Afro-Caribbean men may experience the highest incidence of prostate cancer globally. We examined the effect of race/ethnicity on the initiation and maintenance of annual prostate specific antigen screening and the role of physicians in screening continuity in these high risk groups. MATERIALS AND METHODS: Stratified cluster sampling of census tract blocks in Brooklyn, New York yielded 533 male participants 45 to 70 years old. The men were classified into 4 racial/ethnic groups, including white men born in the United States, black men born in the United States, immigrant Jamaican men, and immigrant men from Trinidad and Tobago. Participants recorded the number of prostate specific antigen tests performed in the last 10 years. Subject adherence was calculated as annually screened, less than annually screened and never screened. Multinomial logistic regression was used to compare screening behavior across the ethnic groups. RESULTS: Overall 28.3% of participants reported annual screening, 44.5% reported screening less than annually and 27.2% reported having never been screened. Jamaicans (OR 3.1) and men from Trinidad and Tobago (OR 5.4) were more likely to screen less than annually compared to not at all. However, black American men (OR 0.3), Jamaican men (OR 0.3), and men from Trinidad and Tobago (OR 0.2) were less likely to maintain annual screening compared with white men, as were men who did not undergo an annual physical examination (OR 0.3) and those with low prostate cancer knowledge (0.5). CONCLUSIONS: Afro-Caribbean men are not less likely than white men to undergo initial prostate specific antigen screening but they are much less likely to maintain annual screening. Through comprehensive discussion and annual examinations physicians have an important role in ensuring prostate specific antigen screening continuity. Our results suggest the need for more culturally appropriate outreach efforts and educational interventions to improve screening compliance.

A review of high-risk prostate cancer and the role of neo-adjuvant and adjuvant therapies.

High-risk, localized prostate cancer represents a complex and diverse disease with many available treatment modalities. Patients are often deemed high risk because they are at increased risk for biochemical failure after primary intervention. However, these "high-risk" men may not be at significant risk of dying from their cancer. In this review, an attempt will be made to better define high-risk patients and help identify men at increased risk for mortality, not simply biochemical failure, after a diagnosis of localized prostate cancer. A review of available monotherapies as well as previously successful multimodality treatments will also be presented. Finally, this review will provide a glimpse into the future direction of high-risk prostate cancer multimodal therapy by providing a synopsis several current randomized clinical trials using effective systemic adjuvant therapies following local treatment.