Obstructive sleep apnea hypopnea syndrome and metabolic syndrome: a synergistic cardiovascular risk factor

Metabolic syndrome among commercial truck drivers: The relationship between condition prevalence and crashes

BACKGROUND

Metabolic syndrome (MetS) is especially prevalent among US truck drivers. However, there has been limited research exploring associations between MetS conditions with roadway crashes among truck drivers. The objective of this paper is to assess relationships between specific combinations of individual MetS components and crashes and near-misses.

METHODS

Survey, biometric, and anthropometric data were collected from 817 truck drivers across 6 diverse US states. Survey data focused on demographics and roadway safety outcomes, and anthropometric/biometric data corresponded to five MetS conditions (waist circumference blood pressure, hemoglobin A1c, triglycerides, and high-density lipoprotein [HDL] cholesterol). Logistic regression was used to calculate odds ratios of lifetime crashes and near-miss 1-month period prevalence associated with: 1) specific MetS conditions regardless of presence or absence of other MetS conditions, and 2) specific MetS conditions and counts of other accompanying MetS conditions.

RESULTS

Hypertension was the MetS characteristic most strongly associated with lifetime crash and 1-month near-miss outcomes, while high triglycerides, low HDL cholesterol, and large waist circumference were most commonly present among groups of conditions associated with crashes and near-misses. Overall, an increasing number of specific co-occurring MetS conditions were associated with higher reporting of roadway crashes.

CONCLUSIONS

Specific combinations and higher prevalence of MetS conditions were associated with increased frequency of reported crashes. Moreover, when the co-occurrence of MetS conditions is aggregated, a dose-response relationship with crashes appears. These results suggest that policy changes and interventions addressing MetS may increase driver health and reduce crash risk.

Increased diastolic blood pressure and apnea time contribute to the poor apnea and hypopnea index and life quality of primary snoring: a cohort study combined with external validation

Obstructive sleep apnea hypoventilation syndrome (OSAHS) is a common sleep breathing disorder closely associated with cardiovascular disease. However, the respiratory sleep and related cardiovascular parameters on the apnea and hypopnea index (AHI) and life quality of primary snoring are unclear. We launched a cohort study focused on the association between respiratory sleep and cardiovascular-related parameters and apnea and hypopnea index, incorporating data from 218 patients with primary snoring in our medical center between Jun 1, 2015, and Apr 1, 2016. Thirty patients from Sichuan Cancer Hospital were used for validation. Patients with longer apnea time were more likely to progress to higher AHI (> 30) than controls (OR = 5.66, 95% CI = [2.79, 11.97], p < 0.001). Similarly, if patients have a higher value of diastolic blood pressure, they will also have a higher AHI (> 30) (HR [95% CI] = 3.42 [1.14, 13.65], p = 0.043). According to multivariate analysis, longest apnea time, the mean percentage of SaO2, and neckline length were independent risk factors of overall survival. A predictive model developed based on these factors above yielded a favorable agreement (C-index = 0.872) on the calibration curve. Thirty patients conducted external validation from Sichuan Cancer Hospital, displaying an AUC of 0.833 (0.782-0.884). Increased diastolic blood pressure and apnea time affect AHI level. An AHI prediction model based on these factors above can help clinicians predict the risk of high AHI events.

Improving Diabetes Self-management by Providing Continuous Positive Airway Pressure Treatment to Patients With Obstructive Sleep Apnea and Type 2 Diabetes: Qualitative Exploratory Interview Study

Background

There is a high prevalence of unexplained and unexplored obstructive sleep apnea (OSA) among patients with type 2 diabetes. The daytime symptoms of OSA include severe fatigue, cognitive problems, a decreased quality of life, and the reduced motivation to perform self-care. These symptoms impair the management of both diabetes and daily life. OSA may therefore have negative implications for diabetes self-management. Continuous positive airway pressure (CPAP) therapy is used to treat OSA. This treatment improves sleep quality, insulin resistance, and glycemic control. Although the benefits of using CPAP as a treatment for OSA are clear, the noncompliance rate is high, and the evidence for the perceived effect that CPAP treatment has on patients with type 2 diabetes and OSA is poor.

Objective

The purpose of this study was to analyze the impacts that comorbid diabetes and OSA have on the daily lives of older adults and to investigate the perceived effect that CPAP treatment for OSA has on patients’ diabetes self-management.

Methods

A qualitative follow-up study that involved in-depth, semistructured dyad interviews with couples before and after CPAP treatment (N=22) was conducted. Patients were recruited from the Hilleroed Hospital in Denmark and were all diagnosed with type 2 diabetes, aged >18 years, and had an apnea-hypopnea index of ≥15. All interviews were coded and analyzed via thematic analysis.

Results

The results showed that patients and their partners did not consider OSA to be a serious disorder, as they believed that OSA symptoms were similar to those of the process of aging. Patients experienced poor nocturnal sleep, took frequent daytime naps, exhibited reduced cognitive function, and had low levels of physical activity and a high-calorie diet. These factors negatively influenced their diabetes self-management. Despite the immediate benefit of CPAP treatment, most patients (11/12, 92%) faced technical challenges when using the CPAP device. Only the patients with severe OSA symptoms that affected their daily lives overcame the challenges of using the CPAP device and thereby improved their diabetes self-management. Patients with less severe symptoms rated CPAP-related challenges as more burdensome than their symptoms.

Conclusions

If used correctly, CPAP has the potential to significantly improve OSA, resulting in better sleep quality; improved physical activity; improved diet; and, in the end, better diabetes self-management. However, there are many barriers to undergoing CPAP treatment, and only few patients manage to overcome these barriers and comply with correct treatment.

Dimensional analysis of the upper airway in obstructive sleep apnoea syndrome patients treated with mandibular advancement device: A bi- and three-dimensional evaluation

BACKGROUND

The efficiency of the mandibular advancement device (MAD) in patients with obstructive sleep apnoea syndrome (OSAS) has been demonstrated. Nevertheless, the behaviour of the upper airway once MAD is placed and titrated, and its correlation with the apnoea-hypopnoea index (AHI) is still under discussion.

OBJECTIVES

To analyse the morphological changes of the upper airway through a bi- and three-dimensional study and correlate it with the polysomnographic variable, AHI.

METHODS

Patients were recruited from two different hospitals for the treatment of OSAS with a custom-made MAD. A cone-beam computer tomography and a polysomnography were performed at baseline and once the MAD was titrated.

RESULTS

A total of 41 patients completed the study. Treatment with MAD reduced the AHI from 22.5 ± 16.8 to 9.2 ± 11.6 (p ≤ .05). There was a significant increase of the total airway volume with MAD from 21.83 ± 7.05 cm³ to 24.19 ± 8.19 cm³ , at the expense of the oropharynx. Moreover, the correlation between the improvement of the AHI and the augmentation of the volume of the upper airway was not statistically significant.

CONCLUSIONS

The oral device used in this prospective study increased the mean upper pharyngeal airway volume and significantly reduced the AHI. Future studies that measure the muscular tone are needed to completely understand the association between the AHI and the physiological and anatomical response of the upper airway.

The association between sleep and diabetes outcomes - A systematic review

AIM

This study aimed to systematically review the prevalence of diagnosed sleep disorders in people with diabetes and to determine the association between sleep disorders and blood glucose levels and diabetes outcomes.

METHODS

We conducted a literature search in the following databases: MEDLINE (Pubmed), EMBASE, CINAHL, PsychInfo and Web of Science Citation Index. Meta-analysis (random-effects models) was conducted to estimate the prevalence of sleep disorders in people with diabetes.

RESULTS

Forty-one articles measured the prevalence of sleep disorders in adults with diabetes. The estimated pooled prevalence of sleep disorders in diabetes was estimated to be 52% (95% CI 42-63%). The highest pooled prevalence was observed for unspecified sleep apnea (69%; 95% CI: 59-78%), followed by obstructive sleep apnea (60%; 95% CI 39-80%), and restless leg syndrome (27%; 95% CI 20-34%). Eleven studies examined the association between sleep disorders and diabetes control and complications. The presence of comorbid sleep disorders was associated with increased diabetes outcomes.

CONCLUSIONS

Diagnosed sleep disorders are highly prevalent in people with diabetes. Sleep disorders are associated with diabetes outcomes, though there was considerable heterogeneity across studies.

Examination of Risk for Sleep-Disordered Breathing Among College Football Players

CONTEXT

Professional football linemen are at risk for sleep-disordered breathing (SDB) compared with other types of athletes. It is currently unknown whether college football linemen display a similar risk profile.

OBJECTIVE

(1) To determine for the first time whether college football linemen show risk for SDB and (2) test the hypothesis that SDB risk is higher in college football linemen compared with an athletic comparison group.

DESIGN

Descriptive laboratory study.

SETTING

The Health Risk Assessment Laboratory.

PARTICIPANTS

Male football linemen (n = 21) and track (n = 19) Division I athletes between the ages of 18 and 22 years.

INTERVENTIONS

Participants completed the Multivariable Apnea Prediction Index and Epworth Sleepiness Scale surveys, validated measures of symptoms of sleep apnea and daytime sleepiness, respectively. Neck and waist circumferences, blood pressure, Modified Mallampati Index (MMPI), and tonsil size were determined, followed by body composition assessment using dual-energy X-ray absorptiometry.

MAIN OUTCOME MEASURES

Scores from surveys, anthropometric data, MMPI, and body composition.

RESULTS

Survey data demonstrated a deficiency in sleep quality and efficiency, coinciding with increased self-reported symptoms of apnea (Multivariable Apnea Prediction Index = 0.78) in college linemen relative to track athletes. Neck circumference (44.36 cm), waist circumference (107.07 cm), body mass index (35.87 kg/m²), and percent body fat (29.20%), all of which exceeded the clinical predictors of risk for obstructive sleep apnea, were significantly greater in linemen compared with track athletes. Multivariable Apnea Prediction variables were significantly correlated with MMPI, neck circumference, percent body fat, body mass index, and systolic blood pressure (r ≥ .31, P < .05), indicating that college football linemen are at increased risk for SDB.

CONCLUSIONS

Risk factors for SDB recognized in professional football linemen are also present at the college level. Screening may minimize present or future risk for SDB, as well as the downstream risk of SDB-associated metabolic and cardiovascular disease.

SERUM LIPOPROTEIN-ASSOCIATED PHOSPHOLIPASE A2 IN MALES WITH METABOLIC SYNDROME AND OBSTRUCTIVE SLEEP APNEA

CONTEXT

Lipoprotein-associated phospholipase A2 (Lp-PLA2) is a novel biomarker for cardiovascular diseases (CVD) risk estimation with high specificity for vascular inflammation. Few studies have investigated Lp-PLA2 levels in patients with metabolic syndrome (MetS) and obstructive sleep apnea syndrome (OSAS).

OBJECTIVE

This study aimed to evaluate the role of Lp-PLA2 levels as a marker of vascular inflammation that contributes to cardiometabolic dysfunction in patients with MetS and OSAS.

DESIGN

This is a prospective case-control study.

SUBJECTS AND METHODS

83 men were enrolled. Following anthropometric measurements, laboratory analysis and overnight sleep study, patients were divided into three groups: MetS, OSAS with/without MetS. Serum Lp-PLA2 levels were determined by ELISA method.

RESULTS

Serum Lp-PLA2 levels were statistically significant among the three groups and were higher in OSAS with MetS group than those without MetS. A significant positive relationship between increased Lp-PLA2 level and CRP (C-reactive protein) and apnea-hypopnea index (AHI) was found. Average oxygen saturation (AvO2) and the lowest oxygen saturation were negatively correlated with Lp-PLA2. The number of desaturation events, oxygen desaturation index, AvO2, AHI and CRP were significant predictors of Lp-PLA2.

CONCLUSIONS

Lp-PLA2 levels are associated with OSAS severity and might play an important role in predicting CVD in OSAS with/without MetS.

Liver X Receptor Gene Expression is Enhanced in Children with Obstructive Sleep Apnea-Hyperpnoea Syndrome and Cyclooxygenase-2 (COX-2) is Correlated with Severity of Obstructive Sleep Apnea-Hypopnea Syndrome (OSAHS)

BACKGROUND Liver X receptor (LXR) is a nuclear receptor presenting in macrophages; it works indispensably in lipid metabolism control and also negatively regulates the expression of inflammatory genes in macrophages. There are many LXR-related studies in adults with metabolic syndrome but rare reports in obese children with obstructive sleep apnea-hypopnea syndrome (OSAHS). The aim of this study was to investigate the expression of LXR, cholesterol ester transfer protein (CETP), and cyclooxygenase-2 (COX-2) genes in obese children with OSAHS compared with obese children without OSAHS and non-obese children. MATERIAL AND METHODS Sleep monitoring was conducted in 80 obese children with sleep disorders. Fasting morning blood samples from the 80 obese children and 51 normal children were collected and separated, so that macrophages were obtained after culture. Fluorescence quantitative real-time PCR (RT-PCR) was used to detect expression levels of the LXR, CETP, and COX-2 genes. RESULTS LXR, COX-2, and CETP levels in the OSAHS group were higher than those in the other two groups (P<0.05), and the LXR levels in the group of obese children without OSAHS were higher than those in control group (P<0.05). COX-2 expression in the group with moderate to severe OSAHS was higher than that in the group with mild OSAHS (P<0.05). Meanwhile, there were no significant differences in the LXR and CETP levels between the moderate to severe OSAHS group and the mild OSAHS group (P>0.05). CONCLUSIONS LXR gene expression was significantly increased in obese children with OSAHS. The severity of OSAHS was positively correlated with COX-2 levels.

Sleep architecture and obstructive sleep apnea in obese children with and without metabolic syndrome: a case control study

PURPOSE

Obesity and biochemical parameters of metabolic disorders are both closely related to obstructive sleep apnea (OSA). The aim of this study was to compare sleep architecture and OSA in obese children with and without metabolic syndrome.

METHODS

Forty-two children with metabolic syndrome were selected as case group and 38 children without metabolic syndrome were matched for age, sex, and BMI as control group. The standardized Persian version of bedtime problems, excessive daytime sleepiness, awakenings during the night, regularity and duration of sleep, snoring (BEARS) and Children's Sleep Habits Questionnaires were completed, and polysomnography (PSG) was performed for all study subjects. Scoring was performed using the manual of American Academy of Sleep Medicine for children. Data were analyzed using chi-square test, T test, Mann-Whitney U test, and logistic regression analysis.

RESULTS

Non-rapid eye movement (NREM) sleep and N1 stage in the case group were significantly longer than the control group, while REM sleep was significantly shorter. Waking after sleep onset (WASO) was significantly different between two groups. Severe OSA was more frequent in the control group. Multivariate logistic regression analysis showed that severe OSA (OR 21.478, 95 % CI 2.160-213.600; P = 0.009) and REM sleep (OR 0.856, 95 % CI 0.737-0.994; P = 0.041) had independent association with metabolic syndrome.

CONCLUSIONS

Obese children with metabolic syndrome had increased WASO, N1 sleep stage, and severe OSA. But the results regarding sleep architecture are most likely a direct result of OSA severity. More longitudinal studies are needed to confirm the association of metabolic syndrome and OSA.

Sleep-disordered breathing during pregnancy: future implications for cardiovascular health

IMPORTANCE

Cardiovascular disease (CVD) is a common condition in postreproductive females. Key risk factors for later-life CVD include gestational hypertension (GHTN) and preeclampsia (PE). Although several risk factors of hypertension in pregnancy are well recognized, a novel risk factor that has emerged recently is sleep-disordered breathing (SDB), a condition characterized by repeated closure of the upper airway during sleep with disrupted ventilation and sleep fragmentation. In the nonpregnant population, SDB is now known to play a causal role in future CVD.

OBJECTIVE

The aim of this study was to propose the hypothesis that occult SDB during pregnancy may play a role in long-term CVD in women who had hypertensive disorders of pregnancy.

EVIDENCE ACQUISITION

This study is a review and synthesis of empirical evidence that links SDB to GHTN/PE and GHTN/PE to future CVD.

RESULTS

An increasing body of evidence supports the relationship between SDB and hypertensive disorders of pregnancy via mechanisms of inflammation, oxidative stress, and endothelial dysfunction. It is well established that hypertensive disorders of pregnancy are associated with long-term risk for CVD via similar mechanisms. However, no studies have addressed the potential role of SDB in long-term outcomes of women with GHTN/PE during pregnancy.

CONCLUSIONS

Given the suggested mechanisms that explain these associations, it is plausible that SDB during pregnancy may increase long-term cardiovascular morbidity and mortality.

RELEVANCE

Pregnancy may offer a window of opportunity for identification and treatment of SDB, which could provide substantial health benefit for many years to come.

Postprandial decrease in LDL-cholesterol in men with metabolic syndrome

BACKGROUND

In some epidemiological studies, blood lipids are determined at non-fasting state, which may impact cardiovascular risk estimation. The aim of this study was to evaluate postprandial LDL-C changes in men with newly diagnosed metabolic syndrome (MetSy).

METHODS

36 male patients were examined: 12 men with and 24 men without MetSy. The fat tolerance test was performed before and after a three-month hypolipidemic treatment. Serum lipids were measured using routine methods, lipid peroxides (LPO) colorimetrically, apolipoproteins A-I, B, and hsCRP immunoturbidimetrically.

RESULTS

The postprandial increase in triglycerides was associated with a decrease in LDL-C and a small decrease in apo B. In men with MetSy, the mean change in LDL-C (-19.5 ± 2.3 mg/dl) was greater than in healthy men (-5.7 ± 3.8 mg/dl). All lipid changes (ΔTG, ΔLDL-C and ΔLPO) were linearly dependent on the postprandial non-LDL-cholesterol. After three months of hypolipidemic treatment, in all men with MetSy, the apoB/apoA-I ratio remained the same as before the therapy.

CONCLUSION

In men diagnosed with MetSy, postprandial decreases in LDL-cholesterol may cause underestimation of cardiovascular risk. After three months of hypolipidemic treatment, there was only a partial reduction in this risk, as the apoB/apoA-I ratio remained the same.

Resveratrol attenuates intermittent hypoxia-induced insulin resistance in rats: involvement of Sirtuin 1 and the phosphatidylinositol-4,5-bisphosphate 3-kinase/AKT pathway

Obstructive sleep apnea can induce chronic intermittent hypoxia (CIH) during sleep and is associated with obesity and diabetes. Resveratrol (RSV), a polyphenolic phytoalexin, can regulate glucose metabolism, thereby reducing insulin resistance. The present study aimed to assess whether RSV attenuates CIH-induced insulin resistance in rats and the underlying mechanisms. A total of 40 rats were randomly assigned into five groups: i) Control; ii) subjected to CIH only; iii) subjected to CIH and treated with 3 mg/kg/day of RSV; iv) subjected to CIH and treated with 30 mg/kg/day of RSV; v) subjected to CIH and treated with 60 mg/kg/day of RSV. All animals were sacrificed following 28 days of treatment. Subsequently, the blood and livers were harvested and blood insulin and glucose levels were measured. Levels of sirtuin (Sirt) 1, insulin receptor (InsR) and glucose transporter 2 (Glut2) in the liver were measured. RSV treatment was demonstrated to suppress weight gain and improve hepatic morphology. RSV treatment also significantly reduced the homeostasis model assessment estimate of insulin resistance of the rats exposed to CIH. This effect occurred in a dose-dependent manner. RSV significantly upregulated liver Sirt1 levels and inhibited InsR and Glut2 expression in the liver. Additionally, RSV activated the phosphorylation of phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) and AKT. The present study demonstrates that RSV prevents CIH-induced insulin resistance in rats. Upregulation of Sirt1 and activation of PI3K/AKT signaling may be involved in this process.

Long-term outcome of catheter ablation in atrial fibrillation patients with coexistent metabolic syndrome and obstructive sleep apnea: impact of repeat procedures versus lifestyle changes

INTRODUCTION

Metabolic syndrome (MS) and obstructive sleep apnea (OSA) are well-known independent risk factors for atrial fibrillation (AF) recurrence. This study evaluated ablation outcome in AF patients with coexistent MS and OSA and influence of lifestyle modifications (LSM) on arrhythmia recurrence.

METHODS AND RESULTS

We included 1,257 AF patients undergoing first catheter ablation (30% paroxysmal AF). Patients having MS + OSA were classified into Group 1 (n = 126; 64 ± 8 years; 76% male). Group 2 (n = 1,131; 62 ± 11 years; 72% male) included those with either MS (n = 431) or OSA (n = 112; no CPAP users) or neither of these comorbidities (n = 588). Patients experiencing recurrence after first procedure were divided into 2 subgroups; those having sporadic events (frequency < 2 months) remained on previously ineffective antiarrhythmic drugs (AAD) and aggressive LSM, while those with persistent arrhythmia (incessant or ≥2 months) underwent repeat ablation. After 34 ± 8 months of first procedure, 66 (52%) in Group 1 and 386 (34%) in Group 2 had recurrence (P < 0.001). Recurrence rate in only-MS, only-OSA, and without MS/OSA groups were 40%, 38%, and 29%, respectively. Patients with MS + OSA experienced substantially higher recurrence compared to those with lone MS or OSA (52% vs. 40% vs. 38%; P = 0.036). Of the 452 patients having recurrence, 250 underwent redo-ablation and 194 remained on AAD and LSM. At 20 ± 6 months, 76% of the redo group remained arrhythmia-free off AAD whereas 74% of the LSM group were free from recurrence (P = 0.71), 33% of which were off AAD.

CONCLUSIONS

MS and OSA have additive negative effect on arrhythmia recurrence following single procedure. Repeat ablation or compliant LSM increase freedom from recurrent AF.

Prevalence of hypertension and circadian blood pressure variations in patients with obstructive sleep apnoea-hypopnoea syndrome

OBJECTIVE

To investigate the prevalence of hypertension and circadian blood pressure (BP) variations in patients with obstructive sleep apnoea-hypopnoea syndrome (OSAHS).

METHODS

Patients referred to a sleep clinic underwent polysomnography with measurement of BP at four time points. They were classified into four groups (control, and mild, moderate or severe sleep apnoea) using the apnoea-hypopnoea index (AHI). Circadian variation was assessed using night-time to daytime mean BP (R(N/D)) and morning to evening mean BP (R(M/E)) ratios.

RESULTS

Hypertension was significantly more common in patients with OSAHS (50.5%) than in controls (30.4%). AHI was positively correlated with hypertension after controlling for related confounders. Mean BP values at all four time points rose with increasing AHI. The increase in night-time and morning values was more pronounced than the increase in daytime and evening values in patients with OSAHS, resulting in loss of the normal BP diurnal rhythm. The R(N/D) and R(M/E) ratios increased with increasing AHI. Daytime BP was significantly correlated with AHI and the lowest oxygen saturation value.

CONCLUSION

OSAHS was shown to be an independent risk factor for hypertension. It was also associated with loss of the normal BP diurnal rhythm.

Cardiac structural and functional changes in old elderly patients with obstructive sleep apnoea-hypopnoea syndrome

OBJECTIVE

To investigate cardiac structural changes in elderly patients with obstructive sleep apnoea-hypopnoea syndrome (OSAHS) and the impact on left ventricular systolic and diastolic function.

METHODS

The study enrolled elderly patients with OSAHS and age-matched healthy control subjects. Cardiac structure, left ventricular diastolic function and left ventricular systolic function were measured using a Doppler ultrasound scanner and compared between the two groups.

RESULTS

The study included 136 patients with OSAHS and 50 healthy control subjects. There were significant differences in the echocardiography indicators that reflect cardiac structure, including interventricular septum, left ventricle posterior wall thickness, and left ventricular mass and mass index between the two groups. There were significant differences between the two groups in the ventricular septal early diastolic myocardial peak velocity/late diastolic myocardial peak velocity (Em/Am), mitral annulus Em/Am, and left ventricle posterior wall Em/Am. There were also significant differences in the indicators of interventricular septum, mitral annulus and left ventricular posterior wall systolic peak velocity between the two groups.

CONCLUSION

Elderly patients with OSAHS demonstrated cardiac structural changes and their left ventricular diastolic and systolic functions were significantly diminished.