Sex differences in the autonomic and cerebrovascular responses to upright tilt.

Sex differences in the regulation of autonomic and cerebrovascular responses to orthostatic stress remain unclear. The objectives of this study were to concurrently investigate autonomic control and cerebrovascular resistance indices, including critical closing pressure (CrCP) and resistance area product (RAP), during upright tilt in men and women. In 13 women and 14 men (18-29 years), ECG, non-invasive blood pressure, middle cerebral artery blood velocity, and end-tidal CO2 (ETCO2) were continuously measured during supine rest and 70° tilt. Heart rate variability (HRV), cardiovagal baroreflex sensitivity (cBRS), and transfer function parameters of dynamic cerebral autoregulation were calculated. Compared to supine, upright tilt increased the low frequency-to-high frequency ratio of HRV in men only (P = 0.044), and decreased cBRS more in women (P = 0.001). Cerebrovascular resistance index (CVRi) increased during tilt only in men (sex-by-time interaction: P = 0.004). RAP was lower in women throughout tilt (main effect of sex: P = 0.022). CrCP decreased during tilt in both sexes (main effect of time: P < 0.001). Normalizing to ETCO2 did not alter the effect of tilt on cerebrovascular resistance. Men displayed a greater increase of sympathetic indices and CVRi during tilt while women had greater parasympathetic withdrawal. We hypothesize that increased sympathetic activity in men may drive sex differences in the cerebrovascular response to upright posture.

Product Substitution After A Real-World Menthol Ban: A Cohort Study.

OBJECTIVES: The province of Ontario, Canada banned menthol in cigarettes and other tobacco products effective January 1st, 2017 adding to an existing flavour ban. However, all flavoured e-cigarettes, flavoured cigars larger than 6g, and alcohol flavoured cigars without filters over 1.4g were exempted. This paper examines the association between use of flavoured non-cigarette products and self-reported cigarette smoking cessation after the ban. METHODS: Current past-30 day cigarette smokers (N=913) who were 16 years or older, living in Ontario were recruited between September-December 2016 and re-contacted January-August 2018. RESULTS: Both daily and occasional pre-ban menthol cigarette smokers were more likely to use flavoured cigar products (adjusted relative rate, RR=1.53, 95% confidence interval, CI=1.01, 2.31; adjusted RR=1.57, 95% CI=1.06, 2.30) after the ban, while occasional pre-ban menthol cigarette smokers were more likely to use other tobacco products (adjusted RR=1.25, 95% CI=1.02, 1.53) or flavoured other tobacco products (adjusted RR=1.56, 95% CI=1.09, 2.24), conditional on prior use. CONCLUSIONS: Menthol smokers prior to the ban were more likely to use other tobacco products, or flavoured tobacco products, after the ban. These results suggest that comprehensive menthol bans could be more effective without the option of using flavoured tobacco or nicotine products as substitutes.

Targeted neonatal echocardiography (TNE) consult service in a large tertiary perinatal center in Canada.

OBJECTIVE: To describe the utilization and study the factors associated with the impact on clinical management of a new TNE consultation service in a perinatal center. METHODS: This retrospective cohort study included all neonates who underwent TNE consultation at the neonatal unit of Mount Sinai Hospital in Toronto, Canada (November 2011 and July 2015). The consults that had "impact" were defined as those that led to a TNE suggested change in the clinical management within 6 h of its recommendation. Logistic regression analysis was performed to identify factors associated with a change in clinical management following the consultation. RESULTS: A total of 553 consults were performed for 268 infants (gestational age: 27 ± 4 weeks and age at initial consult: 16 (5, 34) days). Patent ductus arteriosus (PDA, 61%), suspected pulmonary hypertension (PH, 27%), and systemic hypotension (SH, 9%) were the common indications. The average consultations increased from 9 in 2012-2013 to 20 per month in 2014-2015. Forty eight percent of consults had an impact on clinical management (PDA scans: 38%, PH: 58%, and SH: 81%, p < 0.01 between all). Male gender (adjusted odds ratio (95% confidence interval): 1.9 (1.0, 3.5); p = 0.04), mechanical ventilation (2.43 (1.2, 4.9); p = 0.01), and scans for PH (7.1 (2.2, 23.2); p < 0.01) and SH (2.6 (1.1, 6.5); p = 0.03) were independently associated with the impact on clinical management. TNE consults identified all incidental cases of major structural defects (n = 4), and six out of ten minor diagnoses. CONCLUSIONS: TNE consult service demonstrated an increasing utilization and a significant impact on clinical management over time especially for non-PDA indications and in situations of high-illness severity. Although, all major cardiac defects were identified, some minor congenital defects were missed by TNEs.