Associations between common sleep disturbances and cardiovascular risk in patients with obstructive sleep apnea: A large-scale cross-sectional study

Obstructive sleep apnea and memory impairments: Clinical characterization, treatment strategies, and mechanisms

Obstructive sleep apnea (OSA), is associated with dysfunction in the cardiovascular, metabolic and neurological systems. However, the relationship between OSA and memory impairment, intervention effects, and underlying pathways are not well understood. This review summarizes recent advances in the clinical characterization, treatment strategies, and mechanisms of OSA-induced memory impairments. OSA patients may exhibit significant memory declines, including impairments in working memory from visual and verbal sources. The underlying mechanisms behind OSA-related memory impairment are complex and multifactorial with poorly understood aspects that require further investigation. Neuroinflammation, oxidative stress, neuronal damage, synaptic plasticity, and blood-brain barrier dysfunction, as observed under exposures to intermittent hypoxia and sleep fragmentation are likely contributors to learning and memory dysfunction. Continuous positive airway pressure treatment can provide remarkable relief from memory impairment in OSA patients. Other treatments are emerging but need to be rigorously evaluated for cognitive improvement. Clinically, reliable and objective diagnostic tools are necessary for accurate diagnosis and clinical characterization of cognitive impairments in OSA patients. The complex links between gut-brain axis, epigenetic landscape, genetic susceptibility, and OSA-induced memory impairments suggest new directions for research. Characterization of clinical phenotypic clusters can facilitate advances in precision medicine to predict and treat OSA-related memory deficits.

Effects of Metabolic Factors on Left Ventricular Diastolic Function in Patients with Obstructive Sleep Apnea

Purpose

The effect of metabolic factors on cardiovascular risk in obstructive sleep apnea (OSA) is unclear. This study aimed to investigate the effect of metabolic factors on the left ventricular diastolic function in patients with OSA.

Patients and Methods

This cross-sectional study included a total of 478 patients with OSA from September 2018 to September 2023. After propensity score matching, wherein 193 patients with OSA with metabolic syndrome (MS) were 1:1 matched to patients with OSA without MS by sex and age, data from 386 patients were ultimately analyzed. Furthermore, all patients were divided into mild, moderate, and severe OSA groups according to their sleep apnea-hypopnea index (AHI). Measurements included nocturnal polysomnography, biochemical testing, and transthoracic echocardiography data.

Results

The AHI in the MS group was higher (30.24±21.69 vs 23.19±17.65, p<0.001) and the lowest oxygen saturation at night was lower (77.67±9.23 vs 80.59±9.26, p<0.001) than those in the non-MS group. Additionally, the left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD), end-diastolic ventricular septal thickness (IVST), left ventricular end-diastolic posterior wall thickness (LVPWT), left atrial internal diameter (LAD), and E peak to A peak velocity ratio (E/A) in the MS group were higher than those in the non-MS group (P<0.05). The E peak to e' peak velocity ratio (E/e') in the MS group was higher than that in the non-MS group (12.02±3.68 vs 11.13±3.12, P=0.011) and was positively correlated with the diagnosis of MS and metabolic factors (r=0.115, p=0.024; r=0.131, p=0.010, respectively). Patients with five metabolic factors had a significantly higher risk of E/e' elevation than patients in the non-MS group (odds ratio=4.238, p=0.007).

Conclusion

MS may be related to OSA severity and left ventricular diastolic dysfunction. An increase in metabolic factors may increase the risk of diastolic dysfunction. Among metabolic factors, blood pressure may be the most important.

High arousal threshold is associated with metabolic syndrome in patients with obstructive sleep apnea

OBJECTIVE

Obstructive sleep apnea (OSA) is associated with metabolic syndrome (MetS). OSA patients with high arousal threshold (ArTH) are less easy to arouse, which leads to more severe hypoxic events. We explored the relationship between high ArTH and MetS in patients with OSA.

METHODS

We conducted a cross-sectional study of 112 patients with OSA (mean age 43.50 ± 11.64 years, 89.29 % male). High ArTH was based on an overnight polysomnography, and defined as none or one of the following conditions: apnea-hypopnea index (AHI) < 30 events/hour, minimum oxygen saturation > 82.5 %, or frequency of hypopnea events > 58.3 %. Metabolic syndrome and its components were defined according to the new International Diabetes Federation definition.

RESULTS

Among the 112 OSA patients, 51 (45.54 %) had MetS and 68 (60.71 %) had high ArTH. Logistic regression, after adjusting for confounders, showed that patients with high ArTH had higher odds for MetS (OR = 4.31, 95 % CI = 1.63-11.42, p = 0.003), central obesity (OR = 5.78, 95 % CI = 1.95-17.16, p = 0.002) and hypertriglyceridemia (OR = 2.84, 95 % CI = 1.11-7.28, p = 0.030) compared to patients with low ArTH. Furthermore, higher ArTH levels were associated with higher values for waist circumference (p-for-trend < 0.001), triglycerides (p-for-trend = 0.042), and systolic blood pressure (p-for-trend = 0.037). Moreover, patients with high ArTH had more apnea events and less hypopnea events.

CONCLUSIONS

High ArTH is associated with MetS in OSA patients. High ArTH is a marker of the severity of cardiometabolic comorbidity in OSA.

Urinary Epinephrine Sulfate Can Predict Cardiovascular Risk in Moderate-to-Severe OSA: A Metabolomics-Based Study

Purpose

There are currently no ideal indicators for predicting the cardiovascular risk of obstructive sleep apnea (OSA). This study aimed to employ urinary metabolomics to detect early cardiovascular risk in patients with moderate-to-severe OSA.

Patients and Methods

Male participants who underwent polysomnography from November 2020 to May 2021 were screened. Clinical data, polysomnography data and urine samples were collected. Untargeted metabolomics analyses of urine were performed. Multivariate analyses and receiver operating characteristic (ROC) curve analyses were subsequently performed to identify potential biomarkers. Associations between metabolites and clinical indicators and cardiovascular risk were examined through linear regression analyses with interaction and mediation analyses.

Results

Thirty-six male participants were included in the study, comprising 22 males with moderate-to-severe OSA and 14 age-matched controls, with an average age of 39.6 ± 9.2 years. We identified 65 metabolites in the study, involving pathways including pyrimidine, androgen, estrogen, vitamin B6 and sulfate/sulfite metabolism. Among them, epinephrine sulfate was the most significantly altered metabolite. ROC analyses highlighted that epinephrine sulfate had the highest area under the curve (AUC=0.883) for detecting moderate-to-severe OSA. Epinephrine sulfate was statistically correlated with OSA severity, hypoxia-related indicators (apnea-hypopnea index: r=0.685; oxygen desaturation index: r=0.743, p<0.0001), arterial stiffness (arterial augmentation index: r=0.361, p=0.031) and long-term cardiovascular risk (Framingham cardiovascular risk: r=0.375, p=0.024). Linear regression analysis revealed that epinephrine sulfate was significantly associated with an increased in the Framingham risk (β = 0.004, 95% CI = 0.000-0.009, p = 0.049), with the effect partly mediated by systolic blood pressure (27.6%) and not moderated by other factors. Additionally, it also significantly associated with the increased in the arterial augmentation index (β = 0.019, 95% CI = 0.000-0.037, p = 0.046), with the effect fully mediated by blood pressure and not moderated by other indices statistically.

Conclusion

There are significant metabolic pathway alterations in moderate-to-severe OSA patients. Urinary epinephrine sulfate markedly predicts early cardiovascular risk in OSA patients.

Association of the combination of obstructive sleep apnea risk and sleep duration with ideal cardiovascular health metrics in patients undergoing hemodialysis

BACKGROUND

The purpose of this study was to explore the separate and combined associations of obstructive sleep apnea (OSA) risk and sleep duration with ideal cardiovascular health metrics in hemodialysis (HD) patients.

METHODS

470 HD participants (average: 59.48 ± 12.89 y, 281 men) were included in this study. Sleep duration was measured as self-reported average sleep time during the previous month. The OSA risk was assessed using the STOP-BANG questionnaire. Participants were divided into three groups based on the number of ideal cardiovascular health (CVH) metrics: 0-2,3-4, and 5-7. Ordinal logistic regression was conducted to model the associations of CVH metrics with sleep duration, OSA risk, and their combined effects by adjusting for specific covariates.

RESULTS

After adjusting for covariates, short sleep duration (< 7 h) (OR = 0.53; 95% CI [ 0.30, 0.92]) and OSA risk (OR = 0.58; 95% CI [0.32, 0.83]) were negatively associated with better CVH (ideal vs. intermediate; intermediate vs. poor), respectively. For HD patients with both short sleep duration and OSA risk, the odds of ideal CVH metrics were reduced by 72% (odds ratio 0.28 [95% CI 0.13, 0.60]).

CONCLUSIONS

Short sleep duration and OSA risk are separately and jointly associated with poor CVH in hemodialysis patients. Suitable interventions for sleep may minimize the risk of developing cardiovascular disease.