Obstructive sleep apnea and peripheral vascular disease: a systematic review based on current literature

Effects of obstructive sleep apnea on retinal microvasculature

AIM

To detect retinal microvascular variations in obstructive sleep apnea syndrome patients.

METHODS

This prospective, observational case-control study included healthy controls and patients with mild, moderate, and severe obstructive sleep apnea syndrome. Vascular parameters, foveal avascular area, and flow areas in macula-centered, 6.00×6.00 mm2 scan size optical coherence tomography angiography images were compared.

RESULTS

The control group had the highest whole image, parafoveal, and perifoveal vessel density among the groups in both superficial and the deep capillary plexus (all P<0.05). Rapid eye movement sleep apnoea-hypopnoea index was reversely correlated with whole (Rho=-0.195, P=0.034), parafoveal (Rho=-0.242, P=0.008), perifoveal (Rho=-0.187, P=0.045) vessel density in the superficial capillary plexus, and whole (Rho=-0.186, P=0.046), parafoveal (Rho=-0.260, P=0.004), perifoveal (Rho=-0.189, P=0.043) vessel density in the deep capillary plexus, though the mean and non-rapid eye movement sleep apnoea-hypopnoea index related with only parafoveal vessel density in the superficial capillary plexus (Rho=-0.213, P=0.020; Rho=-0.191, P=0.038) and the deep capillary plexus (Rho=-0.254, P=0.005; Rho=-0.194, P=0.035).

CONCLUSION

This study shows decreased vessel density and its reverse correlation with the apnoea-hypopnoea index in patients with obstructive sleep apnea syndrome.

Relationship Between Peripheral Arterial Diseases and Obstructive Sleep Apnea: A Systematic Review

Although the effects of obstructive sleep apnea (OSA) on the cardiovascular outcomes of coronary artery disease (CAD) have been well-established, its significance on the occurrence of peripheral arterial disease (PAD) remains debatable. Prompt diagnosis and treatment of OSA would help reduce cardiovascular comorbidities. Our study aimed to assess the relationship between OSA and PAD and report any statistical association between the two conditions. Here, we investigated the prevalence and association of OSA in PAD based on related articles from PubMed, Embase, and the Cochrane Library. All databases were systematically searched from January 2000 to December 2020. A total of 238 articles deemed relevant were assessed for eligibility, of which seven articles were selected for the systematic review. Seven prospective cohorts were qualified for inclusion, which included 26,881 male and 34,403 female patients (N = 61,284). The retrieved articles described OSA severity based on the apnea-hypopnea index and reported increased OSA prevalence in PAD patients. The Epworth sleepiness scale showed no association between OSA severity, poor ankle-brachial index values, and increased daytime sleepiness. The prevalence of OSA increased in patients with PAD. Further research and prospective clinical trials are required to establish strong associations between OSA and PAD to make appropriate changes in patient management algorithms and improve their outcomes.

Moderate to severe obstructive sleep apnea is independently associated with inter-arm systolic blood pressure difference: Tokyo Sleep Heart Study

OBJECTIVE

Obstructive sleep apnea (OSA) is recognized as an independent risk factor for cardiovascular disease. On the other hand, inter-arm systolic blood pressure difference (IAD), inter-ankle systolic blood pressure difference (IAND), and ankle-brachial index (ABI) are all known predictors of cardiovascular events. The aim of the present study was to investigate the association between OSA and four-limb blood pressure differences.

METHODS

We conducted this cross-sectional study in a large sleep cohort from Tokyo Sleep Heart Study. In 2643 consecutive patients who visited our sleep clinic for polysomnography between 2005 and 2017, all the patients underwent blood pressure measurement simultaneously in all the four limbs by oscillometric methods.

RESULTS

The prevalence rate of IAD ≥10 mmHg was significantly higher in the moderate OSA (15 ≤ apnea-hypopnea index [AHI] < 30) group (4.2%) and severe OSA (AHI ≥ 30) group (4.6%) than that in the no/mild (AHI < 15) OSA group (1.4%). Multivariate logistic regression analysis also identified moderate to severe OSA as being significantly associated with IAD ≥10 mmHg, even after adjustments for confounding variables (moderate OSA: odds ratio [OR], 4.869; 95% confidence interval [CI], 1.080-21.956; P = 0.039; severe OSA: OR, 5.301; 95% CI, 1.226-22.924; P = 0.026). However, there were no significant associations of the OSA severity with IAND ≥15 mmHg or ABI <0.9.

CONCLUSIONS

Moderate to severe OSA was independently associated with the IAD, not but with the IAND or ABI.

An Update on Obstructive Sleep Apnea for Atherosclerosis: Mechanism, Diagnosis, and Treatment

The occurrence and development of atherosclerosis could be influenced by intermittent hypoxia. Obstructive sleep apnea (OSA), characterized by intermittent hypoxia, is world-wide prevalence with increasing morbidity and mortality rates. Researches remain focused on the study of its mechanism and improvement of diagnosis and treatment. However, the underlying mechanism is complex, and the best practice for OSA diagnosis and treatment considering atherosclerosis and related cardiovascular diseases is still debatable. In this review, we provided an update on research in OSA in the last 5 years with regard to atherosclerosis. The processes of inflammation, oxidative stress, autonomic nervous system activation, vascular dysfunction, platelet activation, metabolite dysfunction, small molecule RNA regulation, and the cardioprotective occurrence was discussed. Additionally, improved diagnosis such as, the utilized of portable device, and treatment especially with inconsistent results in continuous positive airway pressure and mandibular advancement devices were illustrated in detail. Therefore, further fundamental and clinical research should be carried out for a better understanding the deep interaction between OSA and atherosclerosis, as well as the suggestion of newer diagnostic and treatment options.

Prevalence of Obstructive Sleep Apnoea and Its Association With Atherosclerotic Plaques in a Cohort of Subjects With Mild-Moderate Cardiovascular Risk

INTRODUCTION

Classic cardiovascular risk factors do not explain all the cardiovascular events. Obstructive sleep apnoea (OSA) has been proposed as a potential and prevalent cardiovascular risk factor. Our study aimed to describe the prevalence of OSA in a middle-aged cohort with mild-moderate cardiovascular risk and evaluate its association with atherosclerotic disease.

METHODS

This is an observational cross-sectional ancillary study of the ILERVAS project which was aimed to study subclinical arterial disease in a cohort with mild-moderate cardiovascular risk. In a sample of consecutive subjects, we performed a sleep study and evaluate OSA prevalence and its association with carotid and femoral atheroma plaques and atherosclerotic burden.

RESULTS

Overall, 966 subjects with a median age of 57 years (25-75th percentile; 52-62) and a body mass index (BMI) of 28.5kg/m² (25.6-31.6) were included. Of these, 72.6% (69.7%-75.3%) had OSA (apnoea-hypopnoea index (AHI)≥5/h); 35.7% (32.8%-38.8%) had mild OSA (AHI 5-14.9/h) and 36.9% (33.9%-39.9%) had moderate/severe OSA (AHI≥15/h). Mean oxygen saturation and the percentage of time with oxygen saturation<90% (CT90) were associated with atherosclerotic burden (e^β (95%CI) 0.932 (0.892, 0.974); 1.005 (1.002, 1.009), respectively) and total plaque (OR (95%CI) 0.88 (0.797,0.971); 1.013 (1.004,1.021), respectively). No association with the AHI or oxygen desaturation index was found.

CONCLUSIONS

This study confirms a high prevalence of OSA in patients with mild-moderate cardiovascular risk and shows an association between atherosclerotic burden, total and femoral plaque with CT90 and mean oxygen saturation, suggesting the importance of OSA-related hypoxaemia in the induction of atherosclerotic disease.