Sex-Related Differences in Polygraphic Parameters in a Population of Patients with Obstructive Sleep Apnea Syndrome

Sex Differences in the Expression of Cardiac Remodeling and Inflammatory Cytokines in Patients with Obstructive Sleep Apnea and Atrial Fibrillation

Although there is a link between obstructive sleep apnea (OSA) and atrial fibrillation (AF) and numerous investigations have examined the mechanism of AF development in OSA patients, which includes cardiac remodeling, inflammation, and gap junction-related conduction disorder, there is limited information regarding the differences between the sexes. This study analyzes the impact of sex differences on the expression of cardiac remodeling, inflammatory cytokines, and gap junctions in patients with OSA and AF. A total of 154 individuals diagnosed with sleep-related breathing disorders (SRBDs) were enrolled in the study and underwent polysomnography and echocardiography. Significant OSA was defined as an apnea-hypopnea index (AHI) of ≥15 per hour. Exosomes were purified from the plasma of all SRBD patients and incubated in HL-1 cells to investigate their effects on inflammatory cytokines and GJA1 expression. The differences in cardiac remodeling and expression of these biomarkers in both sexes were analyzed. Of the 154 enrolled patients, 110 patients were male and 44 patients were female. The LA sizes and E/e' ratios of male OSA patients with concomitant AF were greater than those of control participants and those without AF (all p < 0.05). Meanwhile, female OSA patients with AF had a lower left ventricular ejection fraction than those OSA patients without AF and control subjects (p < 0.05). Regarding the expression of inflammatory cytokines and GJA1, the mRNA expression levels of GJA1 were lower and those of IL-1β were higher in those male OSA patients with AF than in those male OSA patients without AF and control subjects (p < 0.05). By contrast, mRNA expression levels of HIF-1α were higher in those female OSA patients with and without AF than in control subjects (p < 0.05). In conclusion, our study revealed sex-specific differences in the risk factors and biomarkers associated with AF development in patients with OSA.

Chronic intermittent hypoxia-induced hypertension: the impact of sex hormones

Obstructive sleep apnea, a common form of sleep-disordered breathing, is characterized by intermittent cessations of breathing that reduce blood oxygen levels and contribute to the development of hypertension. Hypertension is a major complication of obstructive sleep apnea that elevates the risk of end-organ damage. Premenopausal women have a lower prevalence of obstructive sleep apnea and cardiovascular disease than men and postmenopausal women, suggesting that sex hormones play a role in the pathophysiology of sleep apnea-related hypertension. The lack of protection in men and postmenopausal women implicates estrogen and progesterone as protective agents but testosterone as a permissive agent in sleep apnea-induced hypertension. A better understanding of how sex hormones contribute to the pathophysiology of sleep apnea-induced hypertension is important for future research and possible hormone-based interventions. The effect of sex on the pathophysiology of sleep apnea and associated intermittent hypoxia-induced hypertension is of important consideration in the screening, diagnosis, and treatment of the disease and its cardiovascular complications. This review summarizes our current understanding of the impact of sex hormones on blood pressure regulation in sleep apnea with a focus on sex differences.

Echocardiographic predictors of mortality in intermediate-risk pulmonary embolism

Data regarding further risk stratification of intermediate-risk pulmonary embolism (IR-PE) are scanty. Whether transthoracic echocardiography may be helpful in further risk assessment of death in such population has still to be proven. Two-hundred fifty-four consecutive patients (51.6% females, age 63.7 ± 17.3 years) with IR-PE admitted to a tertiary regional referral center were enrolled. Patients underwent a complete transthoracic echocardiography within 36 h from hospital admission, on top of clinical assessment, physical examination, computer tomography pulmonary angiography (CTPA), and serum measurement of Troponin I (TnI) levels. The occurrence of 90 day mortality was chosen as primary outcome measure. When compared to survivors, non-surviving IR-PE patients had smaller left-ventricular end-diastolic volumes (39.8 ± 20.9 vs 49.4 ± 19.9 ml/m², p = 0.006) with reduced stroke volume index (SVi) (24.7 ± 10.9 vs 30.9 ± 12.6 ml/m², p: 0.004) and time-velocity integral at left-ventricular outflow tract (VTI_LVOT) (0.17 ± 0.03 vs 0.20 ± 0.04 m, p = 0.0001), whereas no differences were recorded regarding right heart parameters. Cox regression analysis revealed that right atrial enlargement (RAE) (HR 3.432, 5-95% CI 1.193-9.876, p: 0.022), the ratio between tricuspid annulus plane excursion and pulmonary arterial systolic pressure (TAPSE/PASp) (HR 4.833, 5-95% 1.230-18.986, p = 0.024), as well as SVi (HR 11.199, 5-95% CI 2.697-48.096, p = 0.001) and VTI_LVOT (HR 4.212, 5-95% CI 1.384-12.820, p = 0.011) were powerful independent predictors of mortality. Neither CTPA RV/LV nor TnI resulted associated with impaired survival. In intermediate-risk pulmonary embolism, RAE, TAPSE/PASp ratio, SVi, and VTI_LVOT predict independently prognosis to a greater extent than CTPA and TnI.