The association between obstructive sleep apnea and metabolic syndrome: a systematic review and meta-analysis

Heart Disease and Stroke Statistics-2020 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports on the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2020 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, metrics to assess and monitor healthy diets, an enhanced focus on social determinants of health, a focus on the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors, implementation strategies, and implications of the American Heart Association's 2020 Impact Goals.

RESULTS

Each of the 26 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, healthcare administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Obstructive sleep apnea and hypopnea syndrome in patients admitted in a tertiary hospital in Cameroon: Prevalence and associated factors

PURPOSE

Obstructive sleep apnea and hypopnea syndrome (OSAHS) is poorly documented in Sub-Saharan Africa, especially in the hospital setting. The aim of this study was to determine its prevalence and to investigate the associated factors in patients admitted in a tertiary referral hospital in Cameroon.

METHODS

In this cross-sectional study conducted in the Cardiology, Endocrinology and Neurology departments of the Yaounde Central Hospital; all patients aged 21 and older were included consecutively. A sample of randomly selected patients was recorded using a portable sleep monitoring device (PMD). OSAHS was defined as apnea-hypopnea index (AHI) ≥ 5/hour (with > 50% of events being obstructive) and moderate to severe OSAHS as an AHI > 15/hour. Logistic regression was used to identify factors associated to OSAHS.

RESULTS

Of the 359 patients included, 202 (56.3%) patients were women. The mean age (standard deviation) was 58 (16) years. The prevalence of OSAHS assessed by PMD (95% CI) was 57.7% (48.5-66.9%), 53.8% in men and 62.7% in women (p = 0.44). The median (25th-75th percentiles) AHI, body mass index and Epworth Sleepiness Scale score of OSAHS patients were 17 (10.6-26.9)/hour, 27.4 (24.7-31.6) kg/m2 and 7 (5-9) respectively. The only factor associated to moderate to severe OSAHS was hypertension [odds ratio (95% CI)]: 3.24 (1.08-9.72), p = 0.036.

CONCLUSION

OSAHS is a common condition in patients in this health care centre of Cameroon. In the hospital setting, screening for OSAHS in patients with hypertension is recommended.

Examination of the Relationship Between Metabolic Syndrome and Obstructive Sleep Apnea in Iranian Patients with Type 2 Diabetes: A Case-Control Study

INTRODUCTION

Obstructive sleep apnea (OSA) is a common risk factor for metabolic syndrome (MS) that increases the chance of cardiovascular disease, stroke, and mortality. Many studies have been conducted on this matter, but the results are still conflicting. The aim of the present study was to examine the relationship between metabolic syndrome (MS) and obstructive sleep apnea (OSA) in Iranian patients with type 2 diabetes (T2D).

PATIENTS AND METHODS

This matched case-control study was conducted with 190 patients with T2D in Sanandaj, Iran. The data were selected using the demographic questionnaire, clinical and anthropometric measures, the Berlin Questionnaire (BQ), and the National Cholesterol Education Program's Adult Treatment Panel III (NCEP-ATP III). Participants were divided into two groups of high risk of OSA (experimental) and low risk of OSA (control). The data were analyzed using Stata, version 14.

RESULTS

The frequency of MS was higher in the OSA group than the control group (81.1% vs 70.5%), but the group difference was not statistically significant (p=0.127). The results of crude and age-sex adjusted logistic regression analysis revealed no significant association between OSA and the other variables under study (P>0.05). Sensitivity analysis and external adjustment for BMI showed no significant relationship between OSA and the other variables under study (P=0.319).

CONCLUSION

In the present study, no significant association was found between metabolic syndrome (MS) and obstructive sleep apnea (OSA) in patients with T2D; therefore, more studies should be conducted on this subject.

Role of menopause and hormone replacement therapy in sleep-disordered breathing

There are suggestions that the loss of female sex hormones following menopause is critical for the development or progression of sleep-disordered breathing (SDB). We conducted a review of the literature on the role of menopause and hormone replacement therapy (HRT) in SDB risk. There is an increase in SDB during the menopausal transition period, but data on an effect beyond that of increasing age and changes in body habitus are weak or absent. Early community-based, observational studies reported a protective effect by HRT on SDB prevalence, but this could possibly be explained as a healthy user effect. Interventional studies of the effect of HRT on SDB are sparse, with only a few randomized placebo-controlled studies, often performed on small samples of women without clinically significant SDB. HRT regimens have varied and all the studies are fairly old. They do not definitely assure the alleviation of SDB and HRT cannot thus be recommended as treatment for SDB. It is concluded that there is no evidence that female sex hormone changes during menopause per se are able to explain the increase in SDB in midlife women and conclusions on the effect of HRT on SDB cannot be drawn from the current literature.

Role of Obesity in Otorhinolaryngologic Diseases

PURPOSE OF REVIEW

Obesity is a major public health problem associated with various diseases. Improving obesity control and achieving greater patient satisfaction are critical unmet needs. Various otorhinolaryngologic diseases can have negative effects on quality of life or actual health status depending on their type. Over the past decade, the relationship between obesity and otorhinolaryngologic conditions has been investigated. The purpose of this review was to discuss the relationship between obesity and otorhinolaryngological diseases.

RECENT FINDINGS

This is a narrative review on the current state of incidence, effects, and associated mechanisms between obesity and otorhinolaryngologic diseases. In various otologic diseases, otitis media (OM) and hearing loss (HL) are associated with obesity. In rhinologic parts, chronic rhinosinusitis (CRS) and obstructive sleep apnea (OSA) were significantly associated with obesity. Most of these diseases are reported to have higher susceptibility and severity as body mass index (BMI) increases. However, the incidence of head and neck cancer (HNC) was inversely associated with obesity, especially central adiposity. The relevance of obesity in laryngopharyngeal reflux disease (LPR) and allergic rhinitis (AR) has yet to be clarified, and this remains controversial. This review provides a comprehensive overview of the current state of incidence, effects, and associated mechanisms between obesity and otorhinolaryngologic diseases. Various otorhinolaryngological diseases are related to obesity. As obesity can be a negative risk factor in these otorhinolaryngologic diseases, early diagnosis and treatment of these diseases in obese patients will be critical.

Obstructive sleep apnea and comorbidities: a dangerous liaison

Obstructive sleep apnea (OSA) is a highly prevalent disease, and is traditionally associated with increased cardiovascular risk. The role of comorbidities in OSA patients has emerged recently, and new conditions significantly associated with OSA are increasingly reported. A high comorbidity burden worsens prognosis, but some data suggest that CPAP might be protective especially in patients with comorbidities. Aim of this narrative review is to provide an update on recent studies, with special attention to cardiovascular and cerebrovascular comorbidities, the metabolic syndrome and type 2 diabetes, asthma, COPD and cancer. Better phenotypic characterization of OSA patients, including comorbidities, will help to provide better individualized care. The unsatisfactory adherence to CPAP in patients without daytime sleepiness should prompt clinicians to examine the overall risk profile of each patient in order to identify subjects at high risk for worse prognosis and provide the optimal treatment not only for OSA, but also for comorbidities.

The epidemiology of obstructive sleep apnoea and cardiovascular disease

Obstructive sleep apnoea, the most common form of sleep-disordered breathing, is highly prevalent in patients with cardiovascular disease. The last 30 years has seen a plethora of large scale epidemiological studies investigating the relationship between sleep apnoea and cardiovascular outcomes. This review highlights the key epidemiological studies addressing the links between sleep apnoea and hypertension, cardiac arrhythmias, cerebrovascular disease, coronary artery disease, heart failure and pulmonary hypertension, with a particular focus on some of the most recent reports.

Thirty-five alternatives to positive airway pressure therapy for obstructive sleep apnea: an overview of meta-analyses

INTRODUCTION

Positive airway pressure (PAP) devices are generally considered to be the first-line treatment of choice for most adults with obstructive sleep apnea (OSA). However, there are several alternatives. It is important for patients and their sleep providers to be aware of the most up-to-date information regarding the current international literature. Areas covered: The objective is to provide an overview of the meta-analyses evaluating non-PAP treatments for OSA. Four authors searched four databases, including PubMed/MEDLINE through 30 November 2017, for meta-analyses evaluating non-PAP therapies as treatment for OSA. Thirty-five non-PAP treatments were identified and were categorized based on the following anatomical subsites: (1) nose, (2) palate and oropharynx, (3) tongue, (4) skeletal surgery and jaw repositioning, and (5) other surgical and medical interventions. Treatments identified included surgeries, drugs, behavior modifications, nonsurgical weight loss, medical devices, body positioning, and oxygen treatment. Expert commentary: The 35 treatments described vary in their effectiveness in treating OSA in adults. In general, isolated nasal treatments are the least effective, whereas treatments that bypass the upper airway, significantly open the upper airway, and/or address multiple levels of the upper airway are more effective in improving apnea-hypopnea index and lowest oxygen saturation.

Oxidative stress does not contribute to the release of proinflammatory cytokines through activating the Nod-like receptor protein 3 inflammasome in patients with obstructive sleep apnoea

PURPOSE

The study was conducted to test the hypothesis that oxidative stress leads to the release of proinflammatory cytokines by activating the Nod-like receptor protein (NLRP)3 inflammasome in patients with obstructive sleep apnoea (OSA).

METHODS

The study recruited 247 participants who were divided into cases and healthy control groups. OSA patients were subdivided into four subgroups according to sex, blood pressure, body mass index (BMI), and severity of disease. No significant differences were found between cases and controls with respect to age or sex. Peripheral blood samples were collected for analysis after examination, and the serum concentrations of oxidative stress (8-isoprostane), inflammation (interleukin (IL)-18, IL-1β, IL-6, tumour necrosis factor (TNF)-α), and NLRP3 inflammasome components (NLRP3, caspase-1, and ASC) were detected by enzyme-linked immunosorbent assay.

RESULTS

The serum concentrations of both oxidative stress and proinflammatory factors were higher in OSA patients than healthy controls. Subgroup analysis also revealed significant differences according to the apnoea-hypopnea index and BMI. Additionally, correlations were identified between 8-isoprostane and proinflammatory factors (IL-1β, IL-18, and TNF-α). Multiple regression analysis suggested that sleep parameters and BMI affected inflammation. However, no differences were observed in the serum level of NLRP3 inflammasome components between patients and controls. Furthermore, stratified analysis revealed no additional differences.

CONCLUSIONS

The current study suggests that oxidative stress leads to inflammation by mechanisms other than activation of the NLRP3 inflammasome in OSA patients. Furthermore, both sleep apnoea and BMI influenced the serum concentration of inflammatory mediators.

Is obstructive sleep apnea the missing link between metabolic syndrome and second-generation antipsychotics: Preliminary study

BACKGROUND

Metabolic syndrome in individuals taking second-generation antipsychotics is thought to be mediated by antipsychotic-induced weight gain. However, recent literature challenges this notion, and theoretically, it may also be mediated through obstructive sleep apnea (OSA). This study explores the contribution of OSA in antipsychotic-induced metabolic syndrome.

MATERIALS AND METHODS

Forty-three participants suffering from schizophrenia spectrum disorder and major depressive disorder, taking second-generation antipsychotics were included in this study. Treatment history was taken in detail, and lifetime exposure to antipsychotics was converted to olanzapine-equivalent doses. Physical characteristics were noted. OSA was screened through the Hindi version of Berlin Questionnaire. Plasma glucose, serum total cholesterol, serum high-density lipoprotein, and serum triglyceride were measured after 12-h fasting. Adult treatment Panel-III criteria were used to diagnose metabolic syndrome.

RESULTS

Gender distribution was comparable in the study sample. About 27% had continuous illness, 25.6% of participants had metabolic syndrome, and 20.9% were at high risk for sleep apnea. Participants with and without metabolic syndrome were comparable with regard to demographic variables, duration of illness, and lifetime exposure to antipsychotics. Logistic regression depicted that OSA (odds ratio [OR] = 15.09), waist circumference (OR = 1.15), and fasting plasma glucose (OR = 1.21) increased the risk of metabolic syndrome.

CONCLUSION

Results of the present study suggest that metabolic syndrome in participants taking second-generation antipsychotics is mediated through OSA.

Association of sleep disturbances with obesity, insulin resistance and the metabolic syndrome

Insufficient sleep, which has become endemic in recent years, has been variably associated with increased risk of obesity, disorders of glucose and insulin homeostasis, and the metabolic syndrome; to a lesser degree, so has excessive sleep. This review summarizes recent epidemiological and pathophysiological evidence linking sleep disturbances (primarily abnormalities of sleep duration) with obesity, insulin resistance, type 2 diabetes and the metabolic syndrome in children and adults.

Correlation between metabolic syndrome and sleep apnea

The so-called “metabolic syndrome” (MS), constitutes a cluster of metabolic and cardiovascular abnormalities, including fasting glucose, blood pressure, triglycerides, high density lipoprotein cholesterol (HDL-C), and waist circumference that arise from insulin resistance. Obstructive sleep apnea (OSA) syndrome is characterized by recurrent episodes of partial or complete obstruction of the upper airway, involving cessation or significant decreased airflow, with intermittent hypoxemia, frequent arousals from sleep and recurrent oxyhemoglobin desaturations that interfere with normal sleep patterns generating difficulty falling asleep, unrefreshing sleep and loud snoring. The relation between these two entities is known as “Syndrome Z”, and there is no question about the impact of these risk factors on health and disease. This clinical condition presents a growing epidemic Worldwide, affecting approximately 60% of the general population with both MS and OSA due to the constant increase of body mass index in humans. This article presents evidence-based data that focuses on the direct relationship between MS and OSA.

The Apnea-Hypopnea Index Underestimates Systemic Inflammation in Women with Sleep-Disordered Breathing

BACKGROUND

Evidence suggests that sleep-related respiratory and related metabolic compromise may vary between females and males with sleep-disordered breathing (SDB). Our purpose was to elucidate possible gender differences in sleep-associated respiratory and inflammatory parameters in patients with SDB.

MATERIALS AND METHODS

A consecutive number of SDB patients (46 females and 167 males) who underwent polysomnography were retrospectively reviewed. Fibrinogen and C-reactive protein (CRP) concentration, apnea index (ApnI), hypopnea index (HypI), apnea-hypopnea index (AHI), average and minimal SpO₂, duration of snoring, age, and body mass index (BMI) were compared between sexes. Spearman's ρ correlation coefficients between parameters were also calculated.

RESULTS

ApnI and AHI were significantly higher in males. Correlation analysis revealed striking gender differences: only in females, CRP concentration was highly correlated with snoring duration (r = 0.4393), BMI (r = 0.7147), minimal SpO₂ (r = -0.4357), and average SpO₂ (r = -0.4547); in females, HypI was more strongly correlated with AHI (r = 0.8778), average SpO₂ (r = -0.5765), minimal SpO₂ (r = -0.5817), and fibrinogen concentration (r = 0.4614) than in males (r = 0.4373; -0.3295; -0.2969; and 0.0887, respectively); in females, age had a much more pronounced effect on ApnI, HypI, AHI, average oxygen saturation (SaO₂), minimal SaO₂, snoring duration, and CRP and fibrinogen concentration.

CONCLUSIONS

Respiratory compromise in females with SDB is more strongly associated with systemic inflammation than in males with SDB. Although females display a pathological AHI less frequently than males, they reach quite similar pathological SaO₂, CRP, and fibrinogen values. Therefore, AHI may underestimate the pathophysiological systemic effects of SDB in females.

Association of obstructive sleep apnoea with the risk of vascular outcomes and all-cause mortality: a meta-analysis

OBJECTIVE

This study aimed to conduct a meta-analysis to explore and summarise the evidence regarding the association between obstructive sleep apnoea (OSA) and the subsequent risk of vascular outcomes and all-cause mortality.

METHODS

Electronic databases PubMed, Embase and the Cochrane Library were searched to identify studies conducted through May 2016. Prospective cohort studies that reported effect estimates with 95% CIs of major adverse cardiac events (MACEs), coronary heart disease (CHD), stroke, cardiac death, all-cause mortality and heart failure for different levels versus the lowest level of OSA were included.

RESULTS

A total of 16 cohort studies reporting data on 24 308 individuals were included. Of these, 11 studies reported healthy participants, and the remaining five studies reported participants with different diseases. Severe OSA was associated with an increased risk of MACEs (relative risk (RR): 2.04; 95% CI 1.56 to 2.66; P<0.001), CHD (RR: 1.63; 95% CI 1.18 to 2.26; P=0.003), stroke (RR: 2.15; 95% CI 1.42 to 3.24; P<0.001), cardiac death (RR: 2.96; 95% CI 1.45 to 6.01; P=0.003) and all-cause mortality (RR: 1.54; 95% CI 1.21 to 1.97; P<0.001). Moderate OSA was also significantly associated with increased risk of MACEs (RR: 1.16; 95% CI 1.01 to 1.33; P=0.034) and CHD (RR: 1.38; 95% CI 1.04 to 1.83; P=0.026). No significant association was found between mild OSA and the risk of vascular outcomes or all-cause mortality (P>0.05). Finally, no evidence of a factor-specific difference in the risk ratio for MACEs among participants with different levels of OSA compared with those with the lowest level of OSA was found.

CONCLUSIONS

Severe and moderate OSAs were associated with an increased risk of vascular outcomes and all-cause mortality. This relationship might differ between genders. Therefore, further large-scale prospective studies are needed to verify this difference.

Prevalence and risk factors of moderate to severe obstructive sleep apnea syndrome in major depression: a observational and retrospective study on 703 subjects

Background

Several studies have investigated the prevalence and risk factors of depression in subjects with obstructive sleep apnea syndrome. However, few studies have investigated the prevalence and risk factors for obstructive sleep apnea syndrome in major depression. The aim of this study was to examine the prevalence and risk factors of moderate to severe obstructive sleep apnea syndrome in a large sample of individuals with major depression.

Methods

Data from 703 individuals with major depression recruited from the research database of the sleep laboratory of the Erasme Hospital were analysed. An apnea-hypopnea index of ≥15 events per hour was used as cut-off score for moderate to severe obstructive sleep apnea syndrome. Logistic regression analyses were conducted to examine clinical and demographic risk factors of moderate to severe obstructive sleep apnea syndrome in major depression.

Results

The prevalence of moderate to severe obstructive sleep apnea syndrome in major depression is 13.94%. Multivariate logistic regression analysis revealed that male gender, snoring, excessive daytime sleepiness, lower insomnia complaint, presence of metabolic syndrome, age ≥ 50 years, BMI >30 kg/m², ferritin >300 μg/L, CRP >7 mg/L and duration of sleep ≥8 h were significant risk factors of moderate to severe obstructive sleep apnea syndrome in major depression.

Conclusion

Moderate to severe obstructive sleep apnea syndrome is a common pathology in major depression. The identification of these different risk factors advances a new perspective for more effective screening of moderate to severe obstructive sleep apnea syndrome in major depression.

Metabolic Profile in Patients with Mild Obstructive Sleep Apnea

BACKGROUND

Mild obstructive sleep apnea (OSA) is a highly prevalent disorder in adults. However, it is not clear whether mild OSA has significant metabolic complications. This study examined the prevalence of metabolic syndrome (MS) in patients with mild OSA compared to control group.

METHODS

Adults (18-65 years of age) of both genders with a body mass index (BMI) ≤35 kg/m² were included. The mild OSA group comprised of patients with an apnea-hypopnea index (AHI) score of ≥5 but ≤15 events/hr of sleep, independent of other symptoms. The control group (CG) comprised individuals with an AHI of <5 events/hr of sleep and an Epworth Sleepiness Scale score of <10. The following were used for both groups: two questionnaires on sleepiness, the maintenance of wakefulness test, and full-night polysomnography. Anthropometric measurements and fasting blood samples were obtained, including fasting glucose and insulin, total cholesterol and its subfractions [low-density lipoprotein, very low-density lipoprotein, and low-density lipoprotein cholesterol (HDL-c)], triglycerides (TG), and the TG/HDL-c ratio. In addition, the quantitative insulin sensitivity check index and homeostasis model assessment indices were calculated.

RESULTS

Thirty-two percent of mild OSA patients had MS, 43.5% of mild OSA patients had hypertension, 14% showed dyslipidemia, and 56% had prediabetes. The OSA group showed increased TG (CG: 90.0 ± 51.9 vs. OSA: 140.3 ± 78.2 mg/dL, P = 0.004), and TG/HDL-c (CG: 1.9 ± 1.4 vs. OSA: 3.1 ± 2.0, P = 0.05), independent of adjustments. Independent of obesity (BMI <30 kg/m²), there was a negative correlation between total cholesterol and TG with mean oxygen saturation, independent of obesity (BMI <30 kg/m²).

CONCLUSIONS

Our findings showed dysregulation in lipid profiles after adjustments for confounders in the mild OSA group, and there was a correlation between these parameters and sleep hypoxemia. The TG/HDL-c ratio in particular was high, suggesting that it might be investigated as a marker of a detrimental metabolic profile in these patients.

Systems Biology Genetic Approach Identifies Serotonin Pathway as a Possible Target for Obstructive Sleep Apnea: Results from a Literature Search Review

Rationale

Overall validity of existing genetic biomarkers in the diagnosis of obstructive sleep apnea (OSA) remains unclear. The objective of this systematic genetic study is to identify “novel” biomarkers for OSA using systems biology approach.

Methods

Candidate genes for OSA were extracted from PubMed, MEDLINE, and Embase search engines and DisGeNET database. The gene ontology (GO) analyses and candidate genes prioritization were performed using Enrichr tool. Genes pertaining to the top 10 pathways were extracted and used for Ingenuity Pathway Analysis.

Results

In total, we have identified 153 genes. The top 10 pathways associated with OSA include (i) serotonin receptor interaction, (ii) pathways in cancer, (iii) AGE-RAGE signaling in diabetes, (iv) infectious diseases, (v) serotonergic synapse, (vi) inflammatory bowel disease, (vii) HIF-1 signaling pathway, (viii) PI3-AKT signaling pathway, (ix) regulation lipolysis in adipocytes, and (x) rheumatoid arthritis. After removing the overlapping genes, we have identified 23 candidate genes, out of which >30% of the genes were related to the genes involved in the serotonin pathway. Among these 4 serotonin receptors SLC6A4, HTR2C, HTR2A, and HTR1B were strongly associated with OSA.

Conclusions

This preliminary report identifies several potential candidate genes associated with OSA and also describes the possible regulatory mechanisms.

Morning Diastolic Blood Pressure May Be Independently Associated With Severity of Obstructive Sleep Apnea in Non-Hypertensive Patients: A Cross-Sectional Study

STUDY OBJECTIVES

The aim of the study is to verify a possible association between arterial blood pressure and obstructive sleep apnea (OSA) severity in a group of non-hypertensive patients.

METHODS

This is a retrospective study of 1,171 consecutive patients referred to the sleep laboratory with complaints suggestive of OSA who underwent standard diagnostic polysomnography. In total, 454 patients with no History of arterial hypertension nor had received any such treatment were selected from this group.

RESULTS

Patients with severe OSA (apnea-hypopnea index [AHI] ≥ 30 events/h) presented with higher diastolic blood pressure (DBP) in the morning than healthy subjects (AHI < 5 events/h) or those suffering from mild (15 < AHI ≥ 5 events/h) or moderate OSA (30 < AHI ≥ 15 events/h): 86.2 ± 11.3 versus 79.2 ± 8.5, 80.3 ± 10.2 and 81.4 ± 9.6 mmHg, P < .01, respectively. In a linear regression model, a rise in morning DBP was predicted by AHI (ß = 0.14, P < .001) and body mass index (BMI) (ß = 0.22, P < .01), but not by age (ß = 0.01, P = .92), male sex (ß = -0.06, P = .19), or smoking (ß = 0.01, P = .86). In contrast, no association existed between morning systolic blood pressure (SBP) and AHI independently of BMI, sex, age, or smoking. High blood pressure (ie, SBP ≥ 140 mmHg or DBP ≥ 90 mmHg on each of three measurements on different occasions) was predicted by age of 42 years or older, BMI of at least 29 kg/m2, and severe OSA.

CONCLUSIONS

High AHI, independent of obesity, age and sex, was associated with elevated DBP in the morning. Thus, elevated morning DBP may be one of the symptoms related to OSA that warrants specific diagnostics.

COMMENTARY

A commentary on this article appears in this issue on page 861.

Prevalence and risk factors of moderate to severe obstructive sleep apnea syndrome in insomnia sufferers: a study on 1311 subjects

Background

Several studies have investigated the prevalence and risk factors of insomnia in subjects with obstructive sleep apnea syndrome. However, few studies have investigated the prevalence and risk factors for obstructive sleep apnea syndrome in insomnia sufferers. Thus, the aim of this study was to examine the prevalence and risk factors of moderate to severe obstructive sleep apnea syndrome in a large sample of insomnia sufferers.

Methods

Data from 1311 insomnia sufferers who were recruited from the research database of the sleep laboratory of the Erasme Hospital were analysed. An apnea-hypopnea index of ≥15 events per hour was used as the cut-off score for moderate to severe obstructive sleep apnea syndrome. Logistic regression analyses were conducted to examine clinical and demographic risk factors of moderate to severe obstructive sleep apnea syndrome in insomnia sufferers.

Results

The prevalence of moderate to severe obstructive sleep apnea syndrome in our sample of insomnia sufferers was 13.88%. Multivariate logistic regression analysis revealed that male gender, snoring, excessive daytime sleepiness, lower maintenance insomnia complaint, presence of metabolic syndrome, age ≥ 50 & <65 years, age ≥ 65 years, BMI ≥ 25 & <30 kg/m², BMI >30 kg/m², and CRP >7 mg/L were significant risk factors of moderate to severe obstructive sleep apnea syndrome in insomnia sufferers.

Conclusion

Moderate to severe obstructive sleep apnea syndrome is a common pathology in insomnia sufferers. The identification of these different risk factors advances a new perspective for more effective screening of moderate to severe obstructive sleep apnea syndrome in insomnia sufferers.

Relationship between sleep parameters, insulin resistance and age-adjusted insulin like growth factor-1 score in non diabetic older patients

BACKGROUND

Sleep complaints are prevalent in older patients. Sleepiness, short or long sleep duration and obstructive sleep apnea (OSA) are associated with insulin resistance (IR). These parameters have not yet been considered together in the same study exploring the possible association between IR and sleep in older patients. IR is involved in cardiovascular and metabolic diseases, pathologies which are highly prevalent in older patients. Here we assess, in older non-diabetic patients with sleep complaints, the associations between IR and sleep parameters objectively recorded by polysomnography (PSG) rather than self-report. The Growth Hormone/Insulin like growth factor-1 axis could play a role in the development of IR during sleep disorders. The second objective of this study was to analyze the association between sleep parameters and age-adjusted IGF-1 score, which could explain the association between OSA and IR.

METHODS

72 non-diabetic older patients, mean age 74.5 ± 7.8 years, were included in this observational study. We evaluated anthropometric measures, subjective and objective sleepiness, polysomnography, Homeostatic Model Assessment for IR (HOMA-IR) and age-adjusted IGF-1 score. A multivariate regression was used to determine factors associated with HOMA-IR.

RESULTS

The 47 OSA patients were over-weight but not obese and had higher IR than the non-OSA patients. In multilinear regression analysis, apnea-hypopnea index was independently associated with IR after adjustment for several confounding factors. Neither IGF-1 level nor IGF-1 score were different in the two groups.

CONCLUSIONS

We demonstrate that in non-diabetic older patients with sleep complaints, OSA is independently associated with IR, regardless of anthropometric measurements and sleep parameters (sleep duration/sleepiness/arousals). Targeting OSA to reduce IR could be useful in the elderly, although further exploration is required.

Single Nucleotide Polymorphisms in Adiponectin Gene Are Not Directly Associated with Increased Risk of Obstructive Sleep Apnea Syndrome in a Chinese Han Population

PURPOSE

This study aims to test the possible correlation between single nucleotide polymorphisms (SNPs) in the adiponectin gene and increased risk of obstructive sleep apnea syndrome (OSAS) in a Chinese Han population.

MATERIALS AND METHODS

A total of 266 subjects were enrolled into the study to detect 9 SNPs in the adiponectin gene. Multivariate unconditional logistic regression analysis, adjusted for gender and age, was used to estimate the associations of these SNPs with OSAS risk.

RESULTS

No evidence of a direct association was observed between these SNPs and the risk of OSAS in the Chinese Han population. However, the stratified analysis also revealed a remarkable genotype difference for SNP rs6773957 between cases and controls in the overweight subgroup (p < 0.05). In addition, the allele or genotype distributions of rs12495941, rs182052, and rs16861205 had significant differences with regard to the severity of OSAS (p < 0.05). No differences were identified in the other subgroups.

CONCLUSION

The current research demonstrated that the SNPs in the adiponectin gene did not represent susceptibility loci for OSAS in Chinese Han individuals overall. However, variants of rs6773957 have an association with OSAS in overweight individuals. In addition, polymorphisms of rs12495941, rs182052, and rs16861205 are associated with the severity of OSAS.

Changes in sleep duration and risk of metabolic syndrome: the Kailuan prospective study

Using a large longitudinal data set spanning 4 years, we examined whether a change in self-reported sleep duration is associated with metabolic syndrome (MetS). Current analysis included 15,753 participants who were free of MetS during both 2006–2007 and 2010–2011. Sleep duration was categorized into seven groups: ≤5.5 h, 6.0–6.5 h, 7.0 h, 7.5–8.0 h, ≥8.5 h, decrease ≥2 h, and increase ≥2 h. Cox proportional hazards models were used to calculate hazard ratios (HRs) and their confidence intervals (CI) for MetS, according to sleep duration. Compared to the reference group of persistent 7-h sleepers, a decrease of ≥2 h sleep per night was associated with a higher risk of incident MetS (HR = 1.23, 95% CI = 1.05–1.44) in analyses adjusted for age, sex, sleep duration at baseline, marital status, monthly income per family member, education level, smoking status, drinking status, physical activity, body mass index, snoring status and resting heart rate. An increased risk of MetS incidence was also observed in persistent short sleepers (average ≤5.5 h/night; HR = 1.22, 95% CI = 1.01–1.50). This study suggests individuals whose sleep duration decreases ≥2 h per night are at an increased risk of MetS.

Efficacy of nasal continuous positive airway pressure on patients with OSA with erectile dysfunction and low sex hormone levels

PURPOSE

This study aimed to test the hypothesis that erectile dysfunction (ED) is common in men with obstructive sleep apnea (OSA). We also assessed the efficacy of continuous positive airway pressure (CPAP) treatment for ED and sex hormone levels in patients with severe OSA and ED.

METHODS

A total of 153 OSA patients and 60 healthy controls were enrolled in this study. The International Index of Erectile Dysfunction-5 (IIEF-5) score was obtained, and blood samples were collected for analysis of sex hormones after polysomnography. The IIEF-5 score, sex hormone levels, and polysomnographic parameters were re-evaluated in 32 patients with severe OSA and ED after 1 month of CPAP treatment.

RESULTS

The present study showed that the prevalence of ED was 47.1% in all cases and only 13.3% in controls, and a lower sex hormone levels was presented in OSA patients. OSA patients with ED had greater severity of disease, and lower serum levels of follicle stimulating hormone (FSH) and testosterone than OSA patients without ED (p < 0.05). After CPAP therapy, there was a significant increase in the IIEF-5 score, and serum levels of FSH, luteinizing hormone, and testosterone, were elevated compared with baseline levels (p < 0.05). Multivariate regression analysis indicated the serum level of testosterone had impact on the ED.

CONCLUSIONS

OSA patients had lower sex hormone levels and a higher occurrence of ED than controls, and serum level of testosterone had effect on ED. CPAP treatment ameliorated the symptoms of ED and elevated serum levels of FSH, luteinizing hormone, and testosterone.

Assessment of sleep disorders among patients with hypertension and coexisting metabolic syndrome

PURPOSE

The coexistence of hypertension, abdominal obesity, and carbohydrate and lipid metabolism disturbances favors the acceleration of other disease entities - also apart from cardiovascular system disorders. This study was planned to estimate the relationship between the presence of metabolic syndrome and sleep disorders among a group of hypertensive patients.

PATIENTS/METHODS

The study was conducted on unselected group of 261 patients from the Outpatient Hypertension Clinic. The standardized questionnaire was used to collect the data on medical history, prescribed drugs and lifestyle. Sleep disorders were diagnosed based on the Athens Insomnia Scale and STOP-Bang Questionnaire. According to the study protocol, anthropometric parameters (weight, height, waist and neck circumferences), blood pressure, serum lipids and fasting glucose laboratory measurements were performed. Metabolic syndrome was defined according to IDF criteria.

RESULTS

Sleep disorders were recognized in 183 participants of the study - significantly more frequently (P=0.03) among patients with diagnosed metabolic syndrome (120; 75%) in comparison with participants without this disturbance (63; 62.38%). Male gender, poor financial situation, tingling sensations before falling asleep and combination therapy of hypertension significantly increased the risk of sleep disorder occurrence in the group of patients with metabolic syndrome. Night food intake, aging, hypertension combination therapy and poor socioeconomic status were the factors increasing the risk of sleep problems among participants without metabolic syndrome.

CONCLUSIONS

Sleep disorders often coexist with metabolic syndrome in hypertensive patients. A number of factors increase the probability of occurrence of sleep disorders, but most of them are modifiable.

Role of sleep quality in the metabolic syndrome

Emerging evidence has assigned an important role to sleep as a modulator of metabolic homeostasis. The impact of variations in sleep duration, sleep-disordered breathing, and chronotype to cardiometabolic function encompasses a wide array of perturbations spanning from obesity, insulin resistance, type 2 diabetes, the metabolic syndrome, and cardiovascular disease risk and mortality in both adults and children. Here, we critically and extensively review the published literature on such important issues and provide a comprehensive overview of the most salient pathophysiologic pathways underlying the links between sleep, sleep disorders, and cardiometabolic functioning.

Hematologic parameters as the predictors for metabolic syndrome in perimenopausal and postmenopausal women living in urban area: a preliminary report

INTRODUCTION

Prevalence of metabolic syndrome increases drastically during menopausal transition. Chronic inflammation is proposed as the basic pathophysiology of metabolic syndrome (MetS).

AIM OF THE STUDY

To compare mean white blood cell count between perimenopausal and postmenopausal women with and without MetS and find the prevalence of MetS in this patient group.

MATERIAL AND METHODS

A total of 140 healthy perimenopausal and postmenopausal women were interviewed and underwent anthropometric measurements, biochemical investigations for MetS and hematologic parameters. MetS was defined according to the Joint Interim Statement 2009 criteria. The outcome measures were the hematologic parameters between women with and without MetS, correlation of hematologic parameters with MetS components and optimum cutoff for MetS prediction.

RESULTS

The mean age of participants was 50 years. 63.6% were perimenopausal and 36.4% were postmenopausal ones. The prevalence of MetS was 21.4% (95% CI: 15.0-27.9). The women with MetS had a significantly higher level of white blood cell (WBC) counts (7,466.7 and 6,514.6; p = 0.006) and total lymphocyte counts (2,572.0 and 2,207.7; p = 0.003). The optimum cutoff of WBC counts and total lymphocyte counts for prediction of metabolic syndrome was 6,750 cells/ml (sensitivity = 0.633; specificity = 0.591, p = 0.019) and 2,232 cells/ml (sensitivity = 0.667; specificity = 0.518, p = 0.016), respectively.

CONCLUSION

White blood cell and total lymphocyte counts were higher in perimenopausal and postmenopausal women with MetS. However, both hematologic parameters were poor predictors for MetS in peri- and postmenopausal women.

Relationship between sleep-disordered breathing and metabolic syndrome after adjustment with cardiovascular risk factors

AIMS

It is important to identify the risk factors for metabolic syndrome (MetS) in order to prevent the development of cardio-/cerebrovascular diseases. The authors estimated the risk factors for the development of MetS with special emphasis on the severity of sleep-disordered breathing (SDB).

METHODS

We conducted as a cross-sectional study in subjects undergoing intensive health examination (581 men aged 33-84 years). Diagnosis of MetS was based on the criteria of the National Cholesterol Education Program Expert Panel.

RESULTS

The prevalence of MetS in subjects with severe SDB, which was defined as an apnea-hypopnea index (AHI) of 30 or higher, was 40.7%, which was significantly higher than that in the subjects without severe SDB (29.3%). The odds ratio (OR) (95% confidence interval [CI]) of the logarithmic-transformed AHI for MetS was 1.6 (1.1-2.4) after adjustments for age, serum uric acid, logarithmic-transformed serum C-reactive protein, smoking history, exercise history and alcohol history. When the subjects were categorized by the severity of SDB, the OR (95% CI) of severe SDB, which was the only category that showed significant association, was 2.2 (1.2-4.0).

CONCLUSION

A significant association was observed between severe SDB and the presence of MetS in the subjects (all male) of this study.