Obstructive sleep apnoea and diabetes: an update. Curr Opin Pulm Med. 2013;19:631-638. [PMID: 24048079 DOI: 10.1097/mcp.0b013e3283659da5]

The association of diabetes with progression of sleep-disordered breathing based on a prospective cohort

AIM

Prospective studies suggest that sleep-disordered breathing enhances the risk of diabetes. However, it remains unclear whether diabetes could worsen sleep-disordered breathing.

METHODS

The participants from Sleep Heart Health Study underwent two polysomnograms at a 5-year interval. The relationship of baseline diabetes to change in the apnoea-hypopnoea index (AHI) was examined based on general linear models, adjusting for demographics, lifestyles, history of hypertension, pulmonary function, length of follow-up and baseline AHI.

RESULTS

In total, 161 of the 2603 participants were diagnosed with diabetes at the first polysomnograms. Compared with participants without diabetes, those with diabetes had a higher baseline and larger increases in follow-up AHI and obstructive apnoea index (oAI). Diabetes increased 2.52 events per hour (95% confidence interval 0.45-4.59; p = .017) for AHI change and 1.13 events per hour (95% confidence interval 0.04-2.23; p = .042) for oAI change, respectively. In addition, subgroup analysis suggested that the association was consistent across baseline obstructive sleep apnoea severity and body mass index groups.

CONCLUSIONS

Baseline diabetes was associated with worsening sleep-disordered breathing over 5 years, which mainly increased the change in AHI and oAI.

Rapid eye movement sleep loss associated cytomorphometric changes and neurodegeneration

Rapid eye movement sleep (REMS) is essential for leading normal healthy living at least in higher-order mammals, including humans. In this review, we briefly survey the available literature for evidence linking cytomorphometric changes in the brain due to loss of REMS. As a mechanism of action, we add evidence that REMS loss elevates noradrenaline (NA) levels in the brain, which affects neuronal cytomorphology. These changes may be a compensatory mechanism as the changes return to normal after the subjects recover from the loss of REMS or if during REMS deprivation, the subjects are treated with NA-adrenoceptor antagonist prazosin (PRZ). We had proposed earlier that one of the fundamental functions of REMS is to maintain the level of NA in the brain. We elaborate on this idea to propose that if REMS loss continues without recovery, the sustained level of NA breaks down neurophysiologically active compensatory mechanism/s starting with changes in the neuronal cytomorphology, followed by their degeneration, leading to acute and chronic pathological conditions. Identification of neuronal cytomorphological changes could prove to be of significance for predicting future neuronal (brain) damage as well as an indicator for REMS health. Although current brain imaging techniques may not enable us to visualize changes in neuronal cytomorphology, given the rapid technological progress including use of artificial intelligence, we are optimistic that it may be a reality soon. Finally, we propose that maintenance of optimum REMS must be considered a criterion for leading a healthy life.

Sleep behaviours and associated habits and the progression of pre-diabetes to type 2 diabetes mellitus in adults: A systematic review and meta-analysis

INTRODUCTION

Certain sleep behaviours increase risk of type 2 diabetes mellitus (T2DM) in the general population, but whether they contribute to the progression from pre-diabetes to T2DM is uncertain. We conducted a systematic review to assess this.

METHODS

Structured searches were performed on bibliographic databases (MEDLINE, EMBASE and CINAHL) from inception to 26/04/2021 for longitudinal studies/trials consisting of adults⩾18 years with pre-diabetes and sleep behaviours (short or long sleep duration (SD), late chronotype, insomnia, obstructive sleep apnoea, daytime napping and/or night-shift employment) that reported on incident T2DM or glycaemic changes. The Newcastle-Ottawa Scale was used for quality assessment.

RESULTS

Six studies were included. Meta-analysis of three studies (n = 20,139) demonstrated that short SD was associated with greater risk of progression to T2DM, hazard ratio (HR) 1.59 (95% CI 1.29-1.97), I² heterogeneity score 0%, p < 0.0001, but not for long SD, HR 1.50 (0.86-2.62), I² heterogeneity 77%, p = 0.15. The systematic review showed insomnia and night-shift duty were associated with higher progression to T2DM. Studies were rated as moderate-to-high quality.

CONCLUSIONS

Progression from pre-diabetes to T2DM increases with short SD, but only limited data exists for insomnia and night-shift duty. Whether manipulating sleep could reduce progression from pre-diabetes to T2DM needs to be examined.

Sleep and eye disease: A review

There is a growing body of literature on the effects of sleep disorders, in particular obstructive sleep apnoea (OSA), on ocular health, with consistent evidence of an increased risk of floppy eyelid syndrome, non-arteritic anterior ischaemic optic neuropathy, diabetic macular oedema, and other retinal vasculature changes in individuals with OSA. However, reports on OSA's associations with glaucoma, papilloedema, diabetic retinopathy, central serous chorioretinopathy, and keratoconus have been conflicting, while links between OSA and age-related macular degeneration have only been described fairly recently. Despite numerous suggestions that OSA treatment may reduce risk of these eye diseases, well-designed studies to support these claims are lacking. In particular, the ocular hypertensive effects of continuous positive airway pressure (CPAP) therapy for OSA requires further investigation into its potential impact on glaucoma risk and management. Reports of ocular surface complications secondary to leaking CPAP masks highlights the importance of ensuring good mask fit. Poor sleep habits have also been linked with increased myopia risk; however, the evidence on this association remains weak.

Analysis of the proportion and clinical characteristics of obstructive sleep apnea in women with polycystic ovary syndrome

PURPOSE

To investigate the proportion and clinical characteristics of obstructive sleep apnea (OSA) in Chinese patients with polycystic ovarian syndrome (PCOS) through home sleep apnea test (HSAT) and to evaluate the reproductive endocrine and metabolic characteristics in these patients.

METHODS

The study was a cross-sectional analysis of infertile PCOS patients who underwent sleep respiratory monitoring between January and December 2019 at Peking University Third Hospital Reproductive Medical Center and respiratory and critical care medicine department. The prevalence of OSA, body mass index (BMI), menstruation, reproductive endocrine, and metabolic characteristics were collected in patients with PCOS. Logistic regression was performed to identify significant relationships among these factors and OSA.

RESULTS

Amont 328 patients with PCOS, the prevalence of OSA was 40% (131/328), and six cases (5%) were severe. Univariate analysis showed that BMI and blood pressure were significantly higher in patients with OSA than in those without OSA (P < 0.05), whereas the anti-Mullerian hormone was lower than that in patients without OSA. In terms of glucose and lipid metabolism, the glycosylated hemoglobin (HbA1c), fasting plasma glucose, and fasting insulin levels were significantly higher in patients with PCOS and comorbid OSA than in those without OSA (all P < 0.05). Patients with OSA also had higher triglyceride, low-density lipoprotein cholesterol, and high-sensitivity C-reactive protein levels and lower high-density lipoprotein cholesterol levels (P < 0.05). Logistic regression analysis revealed that higher BMI, elevated serum testosterone, and decreased high-density lipoprotein cholesterol (HDL-C) are correlated with occurrence of OSA (P < 0.05).

CONCLUSION

OSA in patients with PCOS was associated with multiple alterations in indexes of reproductive endocrine and metabolic disorders.

Targeted Metabolomics Analysis on Obstructive Sleep Apnea Patients after Multilevel Sleep Surgery

BACKGROUND

Obstructive sleep apnea (OSA) is caused by partial or complete obstruction of the upper airways. Corrective surgeries aim at removing obstructions in the nasopharynx, oropharynx, and hypopharynx. OSA is associated with an increased risk of various metabolic diseases. Our objective was to evaluate the effect of surgery on the plasma metabolome.

METHODS

This study included 39 OSA patients who underwent Multilevel Sleep Surgery (MLS). Clinical and anthropometric measures were taken at baseline and five months after surgery.

RESULTS

The mean Apnea-Hypopnea Index (AHI) significantly dropped from 22.0 ± 18.5 events/hour to 8.97 ± 9.57 events/hour (p-Value < 0.001). Epworth's sleepiness Score (ESS) dropped from 12.8 ± 6.23 to 2.95 ± 2.40 (p-Value < 0.001), indicating the success of the surgery in treating OSA. Plasma levels of metabolites, phosphocholines (PC) PC.41.5, PC.42.3, ceremide (Cer) Cer.44.0, and triglyceride (TG) TG.53.6, TG.55.6 and TG.56.8 were decreased (p-Value < 0.05), whereas lysophosphatidylcholines (LPC) 20.0 and PC.39.3 were increased (p-Value < 0.05) after surgery.

CONCLUSION

This study highlights the success of MLS in treating OSA. Treatment of OSA resulted in an improvement of the metabolic status that was characterized by decreased TG, PCs, and Cer metabolites after surgery, indicating that the success of the surgery positively impacted the metabolic status of these patients.

Obstructive sleep apnea and insulin resistance in children with obesity

STUDY OBJECTIVES

Because existing data investigating obstructive sleep apnea (OSA) and insulin resistance (IR) are inconsistent, we examine OSA and IR in a pediatric obesity clinic.

METHODS

Children (2-18 years) in the obesity clinic (2013-2017) undergoing polysomnography (PSG), anthropometric measurements, and fasting laboratory tests were included. Linear regression assessed OSA defined by the obstructive apnea-hypopnea index (oAHI) with the homeostatic model assessment of insulin resistance (HOMA-IR). Secondary aims assessed oxygen desaturation index (ODI) and age interactions with HOMA-IR. Logistic regression models and receiver operating characteristic analysis were performed to investigate optimal oAHI and ODI cutoffs relative to HOMA-IR ≥ 3.

RESULTS

Eighty children were included (mean age, 11.4 ± 4.0 years; 56% female; 46% Caucasian; median body mass index [BMI], 34.6 kg/m² [interquartile ratio, 29.9-40.1], median BMI z-score, 2.5 [interquartile ratio, 2.3-2.8); 46% with oAHI ≥ 5 events/h. HOMA-IR was higher in the OSA group (oAHI ≥ 5 events/h): 5 vs 3.8 (P = .034). After adjustment for sex, race, and BMI z-score, oAHI ≥ 5 events/h retained significance with HOMA-IR (P = .041). HOMA-IR increased in older children (age ≥ 12 years) when adjusting for waist circumference z-score and waist-height ratio (statistical interaction, P = .020 and .034, respectively). Receiver operating characteristic showed optimal cut points of oAHI and ODI for predicting significant IR 4.9 (area under the curve, 0.70; 95% confidence interval, 0.57-0.83; sensitivity, 0.76; specificity, 0.66) and 4.6 (area under the curve, 0.68; 95% confidence interval, 0.55-0.80; sensitivity, 0.70; specificity, 0.67), respectively.

CONCLUSIONS

In a clinic-based pediatric cohort with obesity, OSA is associated with increased IR even after adjusting for confounders including obesity defined by the BMI z-score. Age ≥ 12 years was associated with AHI relative to IR after adjustment for waist circumference z-score and waist-height ratio. Significant IR could be discriminated by oAHI ≥ 4.9 with moderate sensitivity/specificity. Future studies are needed to verify these findings.

Impaired endothelium-mediated cerebrovascular reactivity promotes anxiety and respiration disorders in mice

Carbon dioxide (CO₂), the major product of metabolism, has a strong impact on cerebral blood vessels, a phenomenon known as cerebrovascular reactivity. Several vascular risk factors such as hypertension or diabetes dampen this response, making cerebrovascular reactivity a useful diagnostic marker for incipient vascular pathology, but its functional relevance, if any, is still unclear. Here, we found that GPR4, an endothelial H⁺ receptor, and endothelial Gα_q/11 proteins mediate the CO₂/H⁺ effect on cerebrovascular reactivity in mice. CO₂/H⁺ leads to constriction of vessels in the brainstem area that controls respiration. The consequential washout of CO₂, if cerebrovascular reactivity is impaired, reduces respiration. In contrast, CO₂ dilates vessels in other brain areas such as the amygdala. Hence, an impaired cerebrovascular reactivity amplifies the CO₂ effect on anxiety. Even at atmospheric CO₂ concentrations, impaired cerebrovascular reactivity caused longer apneic episodes and more anxiety, indicating that cerebrovascular reactivity is essential for normal brain function. The site-specific reactivity of vessels to CO₂ is reflected by regional differences in their gene expression and the release of vasoactive factors from endothelial cells. Our data suggest the central nervous system (CNS) endothelium as a target to treat respiratory and affective disorders associated with vascular diseases.

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.

Effect of dapagliflozin on obstructive sleep apnea in patients with type 2 diabetes: a preliminary study

Objective

The aim of this case-control study was to assess the efficacy of dapagliflozin combined with metformin for type-2 diabetes mellitus (T2DM) with obstructive sleep apnea hypopnea syndrome (OSAHS).

Methods

A total of 36 patients with newly-diagnosed T2DM and OSAHS were randomized divided into two groups. Eighteen OSAHS patients with T2DM, who were treated with dapagliflozin and metformin, were assigned as the dapagliflozin group. These patients were given dapagliflozin and metformin for 24 weeks between February 2017 and February 2018. Another 18 OSAHS patients with T2DM, who were treated with glimepiride and metformin for 24 weeks, were assigned as the control group. Fasting plasma glucose (FPG) level, postprandial blood glucose (PPG), hemoglobin A1C (HbA1c), fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR), blood lipids, body mass index (BMI), blood pressure, apnea-hypopnea index (AHI), minimum oxygen saturation (LSpO₂), and Epworth Somnolence Scale (ESS) score were measured before and at 24 weeks after the initiation of treatment.

Results

In the dapagliflozin group, triglyceride (TG), systolic pressure (SBP) and diastolic pressure (DBP) significantly decreased following treatment, while high-density lipoprotein cholesterol (HDL-C) significantly increased (P < 0.05). Furthermore, a reduction in AHI, an increase in LSpO₂ and a decrease in ESS score were observed in the dapagliflozin group (P < 0.05), but not in the control group. Moreover, blood glucose, HbA1c, HOMA-IR, and BMI significantly decreased in these two groups, and the decrease was more significant in the dapagliflozin group.

Conclusion

These present results indicate that dapagliflozin can significantly reduce glucose, BMI, blood pressure and AHI, and improve hypoxemia during sleep and excessive daytime sleepiness, which thereby has potential as an effective treatment approach for OSAHS.

The Veterans Affairs Continuous Positive Airway Pressure Use and Diabetic Retinopathy Study

SIGNIFICANCE

Obstructive sleep apnea has been linked to the development and progression of diabetic retinopathy. In this study, diabetic patients compliant with continuous positive airway pressure therapy (CPAP) for sleep apnea were less likely to have retinopathy, emphasizing the benefits and potential therapeutic role of CPAP in individuals with both conditions.

PURPOSE

The aim of this study was to compare the prevalence of diabetic retinopathy in type 2 diabetic patients with obstructive sleep apnea who were compliant with CPAP therapy with those who were not compliant with CPAP therapy.

METHODS

A retrospective cross-sectional review of type 2 diabetic patients using CPAP for obstructive sleep apnea was conducted. The prevalence of retinopathy was identified, and groups with and without retinopathy were compared using univariate analyses and multivariate logistic regression.

RESULTS

The prevalence of retinopathy was 19.6% (n = 321). Retinopathy was significantly less prevalent in those compliant with CPAP (odds ratio, 0.54; 95% confidence interval, 0.31 to 0.94; P = .04). The relationship remained statistically significant when adjusting for other factors known to impact the course of diabetic eye disease.

CONCLUSIONS

Increased CPAP compliance may mitigate the risk of developing diabetic retinopathy in type 2 diabetic patients with obstructive sleep apnea.

The prevalence of obstructive sleep apnoea in women with polycystic ovary syndrome: a systematic review and meta-analysis

BACKGROUND

Obesity is a common risk factor for polycystic ovary syndrome (PCOS) and obstructive sleep apnoea (OSA). Both PCOS and OSA are associated with increased risk of type 2 diabetes and cardiovascular disease. Hence, it is important to determine the burden of OSA in women with PCOS.

METHODS

We searched electronic databases (MEDLINE, Embase, CINAHL, PsycINFO, Scopus, Web of Science, OpenGrey, CENTRAL), conference abstracts, and reference lists of relevant articles, up to January 2019. No restriction for language or publication status. Studies that examined the presence of OSA in women with PCOS using polysomnography and/or level III devices were eligible for inclusion.

RESULTS

Seventeen studies involving 648 participants were included. Our meta-analysis showed that 35.0% (95% CI 22.2-48.9%) of women with PCOS had OSA. This prevalence was not affected by variation in PCOS definition between studies. Approximately one-tenth of the variation in OSA prevalence was related to differences in study population (higher in adults than adolescents and mixed populations), and around one-tenth was related to sample size (higher in smaller studies). OSA prevalence was markedly higher in obese versus lean women with PCOS, and in women with PCOS compared to controls (odds ratio = 3.83, 95% CI 1.43-10.24, eight studies, 957 participants (349 PCOS and 608 controls)). However, most of the studies were at high risk of selection bias, did not account for important confounders, included predominantly women with class II obesity, and were conducted in one country (USA).

CONCLUSIONS

Future studies need to examine the true prevalence of OSA in a more representative sample of women with PCOS. Nevertheless, our results suggest that the prevalence of OSA in women with PCOS and obesity is high and clinicians should have a high index of suspicion of OSA in these women.

Risk of Incident Obstructive Sleep Apnea Among Patients With Type 2 Diabetes

OBJECTIVE

This study compared the incidence of obstructive sleep apnea (OSA) in patients with and without type 2 diabetes and investigated risk factors for OSA in patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

A retrospective cohort study was performed to compare OSA incidence between adult patients with and without type 2 diabetes matched for age, sex, and BMI. Patients with a prevalent OSA diagnosis were excluded. The study cohort was derived from The Health Improvement Network (THIN), a U.K. primary care database, from 1 January 2005 to 31 December 2017.

RESULTS

There were 3,110 (0.88%) and 5,968 (0.46%) incident OSA cases identified in the 360,250 exposed and 1,296,489 unexposed patient cohorts, respectively. Adjusted incidence rate ratio (aIRR) of OSA in patients with type 2 diabetes compared with those without was 1.48 (95% CI 1.42-1.55; P < 0.001). In a multivariate regression analysis of patients with type 2 diabetes, significant predictors of OSA were diabetes-related foot disease (1.23 [1.06-1.42]; P = 0.005), being prescribed insulin in the last 60 days (1.58 [1.42-1.75]; P < 0.001), male sex (2.27 [2.09-2.46]; P < 0.001), being overweight (2.02 [1.54-2.64]; P < 0.001) or obese (8.29 [6.42-10.69]; P < 0.001), heart failure (1.41 [1.18-1.70]; P < 0.001), ischemic heart disease (1.22 [1.11-1.34]; P < 0.001), atrial fibrillation (1.23 [1.04-1.46]; P = 0.015), hypertension (1.32 [1.23-1.43]; P < 0.001), and depression (1.75 [1.61-1.91]; P < 0.001).

CONCLUSIONS

When considered alongside previous evidence, this study indicates that the association between type 2 diabetes and OSA is bidirectional. In addition to known predictors of OSA, diabetes-related foot disease and insulin treatment were identified as risk factors in patients with type 2 diabetes.

The association between obstructive sleep apnea and metabolic abnormalities in women with polycystic ovary syndrome: a systematic review and meta-analysis

Study Objectives

In this systematic review and meta-analysis, we aimed to examine the relationship between obstructive sleep apnea (OSA) and metabolic abnormalities in women with polycystic ovary syndrome (PCOS).

Methods

Electronic databases (Medline, Embase, Cinahl, PsycInfo, Scopus, Web of Science, Opengrey, and CENTRAL), conference abstracts, and reference lists of relevant articles were searched. No restriction was applied for language or publication status.

Results

Six studies involving 252 participants were included. Women with PCOS and OSA had significantly higher body mass index (mean difference [MD]: 6.01 kg/m2, 95% confidence intervals [CI]: 4.69-7.33), waist circumference (MD: 10.93 cm, 95% CI: 8.03-13.83), insulin resistance, systolic and diastolic blood pressure, and worse lipids' profile and impaired glucose regulation compared with women with PCOS without OSA. Most studies did not adjust for weight in their between-groups analysis. Total and free testosterone levels were not significantly different between the two groups. The majority of studies were found to be at high risk of selection bias, did not account for important confounders, were conducted in one country (United States), and used different methodologies to assess testosterone levels (preventing a meta-analysis for this specific outcome).

Conclusions

OSA is associated with obesity and worse metabolic profiles in women with PCOS. However, whether the effects of OSA are independent of obesity remain unclear. As OSA is a treatable condition, research focused on the independent effects of OSA on key clinical outcomes in women with PCOS, including fertility, psychological health, type 2 diabetes, and cardiovascular risk, is lacking and needed. PROSPERO registration number: CRD42016048587.

The Interlinked Rising Epidemic of Insufficient Sleep and Diabetes Mellitus

For healthy existence, humans need to spend one-third of their time sleeping. Any qualitative or quantitative disturbances in sleep would result in an increased prevalence of obesity, metabolic disorders, diabetes, cardiovascular diseases, and hypertension. The paper aims to highlight the growing global problem of insufficient sleep and its significant impact on the rising incidence of diabetes mellitus. An extensive literature search was done in all major databases for "insufficient sleep" and "Diabetes Mellitus" for this review. Shorter (<6 h) and longer (>9 h) durations of sleep have been adversely related to insulin resistance. Though the relation between insufficient sleep and diabetes mellitus is more or less understood, little is known about how oversleeping or hypersomnia (10⁻12 h) increases the risk of diabetes. The relationship between sleep disturbances and diabetes is dual-sided, as chronic sleep disturbances would elevate the risk of developing insulin resistance, while diabetes would worsen the quality of sleep. Both the qualitative and quantitative disturbances in sleep significantly increase the risk of developing diabetes, which is supported by numerous community-based and hospital-based epidemiological studies discussed in this review. Obstructive sleep apnea is one of the most common sleep disorders and is characterized by chronic intermittent hypoxia and increased sympathetic activity, thus leading to a higher prevalence of diabetes. Sleep therapy may serve as a low-cost method for fighting against the rising epidemic of diabetes.

Sleep-Disordered Breathing Is Associated with Metabolic Syndrome in Outpatients with Diabetes Mellitus Type 2

BACKGROUND

Metabolic syndrome (MS) and sleep-disordered breathing (SDB) are highly prevalent in patients with diabetes mellitus type 2 (DM2). The present study examined whether there is an independent association between SDB and MS in a sample of outpatients with DM2.

METHODS

MS was determined in 679 patients of the DIACORE-SDB substudy, a study of outpatients with DM2. According to the National Cholesterol Education Program (NCEP) criteria, MS is defined by at least three of the following five criteria: waist circumference of >102 cm (men)/>88 cm (women), blood pressure of ≥130/85 mmHg, a fasting triglyceride level of >150 mg/dl, high-density lipoprotein (HDL) of <40 mg/dl (men)/<50 mg/dl (women), and a fasting glucose level of ≥110 mg/dl. The apnea-hypopnea index (AHI) was assessed with a 2-channel ambulatory monitoring device and used to define the severity of SDB (AHI < 15.0: no/mild SDB; AHI 15.0-29.9: moderate SDB; AHI ≥ 30.0: severe SDB).

RESULTS

228 (34%) of the 679 participants (mean age 66 years, mean body mass index (BMI) 31.2 kg/m², and mean AHI 14/hour) had SDB. MS was significantly more frequent in patients with more severe SDB (no/mild SDB vs. moderate SDB vs. severe SDB: 72% vs. 79% vs. 85%, respectively, p = 0.038). Logistic regression analysis adjusted for sex, age, obesity (BMI ≥ 30 kg/m²), and the HOMA index showed a significant association between the AHI and the presence of MS (OR (95%CI) = 1.039 (1.011; 1.068); p = 0.007). Further, male sex, obesity, and the HOMA index were significantly associated with MS.

CONCLUSION

SDB is significantly and independently associated with MS in outpatients with DM2.

Association of usual sleep quality and glycemic control in type 2 diabetes in Japanese: A cross sectional study. Sleep and Food Registry in Kanagawa (SOREKA)

Objectives

Excessively short and long sleep durations are associated with type 2 diabetes, but there is limited information about the association between sleep quality and diabetes. Accordingly, the present study was performed to investigate this relationship.

Materials and methods

The subjects were 3249 patients with type 2 diabetes aged 20 years or older. Sleep quality was assessed by using the Pittsburgh Sleep Quality Index (PSQI). A higher global PSQI score indicates worse sleep quality, and a global PSQI score >5 differentiates poor sleepers from good sleepers.

Results

The mean global PSQI score was 5.94 ± 3.33, and 47.6% of the patients had a score of 6 or higher. Regarding the components of the PSQI, the score was highest for sleep duration, followed by subjective sleep quality and then sleep latency in decreasing order. When the patients were assigned to HbA1c quartiles (≤ 6.5%, 6.6–7.0%, 7.1–7.8%, and ≥ 7.9%), the top quartile had a significantly higher global PSQI score than the other quartiles. The top HbA1c quartile had a sleep duration of only 6.23 ± 1.42 hours, which was significantly shorter than in the other quartiles. Also, sleep latency was 25.3 ± 31.8 minutes in the top quartile, which was significantly longer (by approximately 20 minutes) than in the other quartiles. When analysis was performed with adjustment for age, gender, BMI, smoking, and other confounders, the global PSQI score was still significantly higher and sleep duration was shorter in the top HbA1c quartile (HbA1c ≥ 7.9%).

Conclusions

Japanese patients with type 2 diabetes were found to have poor subjective sleep quality independently of potential confounders, especially those with inadequate glycemic control. Impairment of sleep quality was associated with both increased sleep latency and a shorter duration of sleep.

Interactions between and Shared Molecular Mechanisms of Diabetic Peripheral Neuropathy and Obstructive Sleep Apnea in Type 2 Diabetes Patients

Type 2 diabetes (T2D) accounts for about 90% of all diabetes patients and incurs a heavy global public health burden. Up to 50% of T2D patients will eventually develop neuropathy as T2D progresses. Diabetic peripheral neuropathy (DPN) is a common diabetic complication and one of the main causes of increased morbidity and mortality of T2D patients. Obstructive sleep apnea (OSA) affects over 15% of the general population and is associated with a higher prevalence of T2D. Growing evidence also indicates that OSA is highly prevalent in T2D patients probably due to diabetic peripheral neuropathy. However, the interrelations among diabetic peripheral neuropathy, OSA, and T2D hitherto have not been clearly elucidated. Numerous molecular mechanisms have been documented that underlie diabetic peripheral neuropathy and OSA, including oxidative stress, inflammation, endothelin-1, vascular endothelial growth factor (VEGF), accumulation of advanced glycation end products, protein kinase C (PKC) signaling, poly ADP ribose polymerase (PARP), nitrosative stress, plasminogen activator inhibitor-1, and vitamin D deficiency. In this review, we seek to illuminate the relationships among T2D, diabetic peripheral neuropathy, and OSA and how they interact with one another. In addition, we summarize and explain the shared molecular mechanisms involved in diabetic peripheral neuropathy and OSA for further mechanistic investigations and novel therapeutic strategies for attenuating and preventing the development and progression of diabetic peripheral neuropathy and OSA in T2D.

Obstructive sleep apnoea and polycystic ovary syndrome: A comprehensive review of clinical interactions and underlying pathophysiology

Polycystic ovary syndrome (PCOS) is the most prevalent endocrine disorder in women of reproductive age. PCOS is associated with multiple comorbidities including, obesity, insulin resistance and type 2 diabetes, as well as mood disorders and impaired quality of life (QoL). Obstructive sleep apnoea (OSA) is also a common medical condition that is often undiagnosed, particularly in women. OSA is associated with a similar spectrum of comorbidities to that observed in PCOS, including manifestations of the metabolic syndrome and impaired QoL, whilst obesity frequently constitutes a common denominator in the pathophysiology of both OSA and PCOS. Hence, it is not surprising that OSA and PCOS may coexist in women of reproductive age, and the current clinical guidelines on the management of PCOS recommend screening for OSA symptoms in overweight/obese women with PCOS. In this review, we examine the relationship between OSA and PCOS and explore the potential underlying mechanisms that link these two conditions.

Obstructive sleep apnoea in diabetes: Does it matter?

Obstructive sleep apnoea (OSA) is very common in patients with Type 2 diabetes (T2D), which is not surprising considering that obesity is a common risk factor for both conditions. In general population studies, OSA has been shown to be associated with several comorbidities including increased risk of road traffic accidents, T2D, hypertension and lack of nocturnal dipping of blood pressure, hyperlipidaemia, increased inflammation, increased risk of cardiovascular disease and mortality, increased risk of atrial fibrillation, worse quality of life, and erectile dysfunction. However, the impact of OSA on diabetes-related vascular and metabolic outcomes remains unclear. Furthermore, the impact of continuous positive airway pressure (CPAP) treatment in patients with T2D is also unclear. This unclarity regarding the impact of OSA and CPAP in patients with T2D has possibly contributed to the lack of screening for OSA in patients with T2D in the UK despite the high prevalence of OSA in patients with T2D. In this commentary, I provide an overview about OSA with a particular focus on its role and impact in patients with T2D.

Circulating exosomes in obstructive sleep apnea as phenotypic biomarkers and mechanistic messengers of end-organ morbidity

Obstructive sleep apnea (OSA), the most severe form of sleep disordered breathing, is characterized by intermittent hypoxia during sleep (IH), sleep fragmentation, and episodic hypercapnia. OSA is associated with increased risk for morbidity and mortality affecting cardiovascular, metabolic, and neurocognitive systems, and more recently with non-alcoholic fatty liver disease (NAFLD) and cancer-related deaths. Substantial variability in OSA outcomes suggests that genetically-determined and environmental and lifestyle factors affect the phenotypic susceptibility to OSA. Furthermore, OSA and obesity often co-exist and manifest activation of shared molecular end-organ injury mechanisms that if properly identified may represent potential therapeutic targets. A challenge in the development of non-invasive diagnostic assays in body fluids is the ability to identify clinically relevant biomarkers. Circulating extracellular vesicles (EVs) include a heterogeneous population of vesicular structures including exosomes, prostasomes, microvesicles (MVs), ectosomes and oncosomes, and are classified based on their size, shape and membrane surface composition. Of these, exosomes (30-100nm) are very small membrane vesicles derived from multi-vesicular bodies or from the plasma membrane and play important roles in mediating cell-cell communication via cargo that includes lipids, proteins, mRNAs, miRNAs and DNA. We have recently identified a unique cluster of exosomal miRNAs in both humans and rodents exposed to intermittent hypoxia as well as in patients with OSA with divergent morbid phenotypes. Here we summarize such recent findings, and will focus on exosomal miRNAs in both adult and children which mediate intercellular communication relevant to OSA and endothelial dysfunction, and their potential value as diagnostic and prognostic biomarkers.

Obstructive sleep apnoea and the need for its introduction into dental curricula

Obstructive sleep apnoea (OSA) is a major health problem which causes blood oxygen desaturation that may initiate a cascade of events via inflammatory cytokines and adrenocorticotrophic hormone that may have impact upon quality of life and lead to potential life-threatening events. Even though OSA affects an increasing number of individuals, the role of dental practitioners in recognition, screening and management has not developed accordingly. The goal of this article was to provide updated information to dental practitioners on pathophysiology, consequences and treatment options of OSA with a focused discussion on oral appliance (OA) therapy, as this topic is not routinely included in current dental curricula of many dental schools. Additionally, we present a template dental curriculum for predoctoral and/or postdoctoral students in education regarding sleep disordered breathing.

Prevalence and Associations of Obstructive Sleep Apnea in South Asians and White Europeans with Type 2 Diabetes: A Cross-Sectional Study

STUDY OBJECTIVES

To assess and compare obstructive sleep apnea (OSA) prevalence in South Asians and White Europeans with type 2 diabetes mellitus (T2DM). Secondary aims included exploring possible causes for observed ethnic differences.

METHODS

A cross-sectional study of patients with T2DM recruited from secondary care diabetes clinics. OSA was defined as an apnea-hypopnea index (AHI) ≥ 5 events/h using home-based, multi-channel respiratory monitoring.

RESULTS

Two hundred thirty-four patients (105 South Asian and 129 White Europeans) were studied. The prevalence of mild, moderate, and severe OSA in South Asians was 36.2% (n = 38/105), 9.5% (n = 10/105), and 5.7% (n = 6/105) respectively. After adjustment, OSA was associated with a higher body mass index in South Asians. OSA was significantly less common in South Asians compared to White Europeans (51.4% [54/105] versus 75.2% [97/129], P < .001). OSA was also less severe in South Asians compared to White Europeans (median [interquartile range]: AHI 5.1 [1.4-11.5] versus 8.5 [5.0-20.7] events/h, P < .001; time spent with oxygen saturations < 90% 0.5 [0.0-2.9]% versus 4.0 [0.7-14.4]%, P < .001). Logistic regression showed that only obesity measures explained the ethnic differences in OSA.

CONCLUSIONS

South Asians with T2DM are at considerable risk of OSA. OSA in South Asians was associated with obesity. However, OSA prevalence was lower in South Asians than in White Europeans. Obesity measures accounted for the observed ethnic differences. Examining factors contributing to ethnic differences will be important to inform screening and treatment strategies.

Morning cortisol levels and glucose metabolism parameters in moderate and severe obstructive sleep apnea patients

Obstructive sleep apnea (OSA) has been associated with dysregulation of the hypothalamic-pituitary-adrenal axis and alterations in glucose metabolism with increased risk for type 2 diabetes. The aim of the current study was to compare morning plasma cortisol levels and glucose metabolism parameters between moderate (apnea-hypopnea index (AHI): 15-30 events/h) and severe OSA patients (AHI >30 events/h), with respective controls. A total of 56 male OSA patients, 24 moderate (AHI = 21.1 ± 5.3) and 32 severe (AHI = 49.7 ± 18.1), underwent a full-night polysomnography, oral glucose tolerance test (OGTT), and measurement of morning plasma cortisol levels. These groups were compared to 20 matched subjects in a control group. Morning plasma cortisol levels were statistically lower in severe OSA group than in moderate OSA and control groups (303.7 ± 93.5 vs. 423.9 ± 145.1 vs. 417.5 ± 99.8 pmol/L, P < 0.001). Significant negative correlations were found between morning plasma cortisol levels and AHI (r = -0.444, P = 0.002), as well as oxygen desaturation index (r = -0.381, P = 0.011). Fasting plasma glucose (5.0 ± 0.5 vs. 5.4 ± 0.7 vs. 4.9 ± 0.6 mmol/L, P = 0.009) was higher in the severe OSA group compared to moderate OSA and controls. Homeostasis model assessment insulin resistance (HOMA-IR) was higher in the severe OSA group compared to moderate OSA and controls (4.6 ± 3.7 vs. 2.7 ± 2.0 and 2.2 ± 1.8, respectively, P = 0.006). In conclusion, our study showed that morning plasma cortisol levels measured at 8 a.m. were significantly lower in severe OSA patients than those in moderate OSA group and controls. Morning plasma cortisol levels showed a negative correlation with AHI and oxygen desaturation index. Additionally, this study confirmed the evidence of glucose metabolism impairment in moderate and severe OSA patients, with more pronounced effect in the severe OSA patients group.

The relationship between obstructive sleep apnea and intra-epidermal nerve fiber density, PARP activation and foot ulceration in patients with type 2 diabetes

BACKGROUND

Obstructive sleep apnea (OSA) is associated with increased nitrosative stress, endothelial dysfunction, and peripheral neuropathy in patients with type 2 diabetes. We hypothesized that OSA is associated with Poly ADP ribose polymerase (PARP) activation, lower intra-epidermal nerve fiber density (IENFD), and diabetic foot ulceration (DFU).

METHODS

A cross-sectional study of adults with type 2 diabetes recruited from a secondary care hospital in the UK. OSA was assessed by multi-channel home-based cardio-respiratory device (Alice PDX, Philips Respironics). DPN was assessed using the Michigan Neuropathy Screening Instrument (MNSI). IENFD and % PAR stained nuclei were assessed using immunohistochemistry staining on skin biopsies. DFU was assessed based on MNSI.

RESULTS

Skin biopsies and DFU data were available from 52 and 234 patients respectively. OSA was associated with lower IENFD (12.75±1.93 vs. 10.55±1.62 vs. 9.42±1.16 fibers/mm of epidermis for no OSA, mild OSA and moderate to severe OSA respectively, p<0.001). Following adjustment, mild (B=-2.19, p=0.002) and moderate to severe OSA (B=-3.45, p<0.001) were independently associated with IENFD. The apnea hypopnea index (AHI) was associated with IENFD following adjustment (B=-2.45, p<0.001). AHI was associated with percentage of PAR stained nuclei following adjustment (B=13.67, p=0.025). DFU prevalence was greater in patients with OSA (7.1% vs. 28.1% vs. 26.2% for patients with no OSA, mild OSA and moderate to severe OSA respectively, p=0.001). Following adjustment, OSA was associated with DFU (OR 3.34, 95% CI 1.19-9.38, p=0.022).

CONCLUSIONS

OSA is associated with lower IENFD, PARP activation and DFU in patients with type 2 diabetes. Our findings suggest that OSA is associated with small fiber neuropathy. PARP activation is a potential mechanisms linking OSA to DPN and endothelial dysfunction in patients with type 2 diabetes. Whether OSA treatment will have a favorable impact on these parameters and DFU requires interventional studies.

Moderate-to-severe obstructive sleep apnea is associated with cerebral small vessel disease

BACKGROUND

Cerebral small vessel disease (SVD) is associated with increased risk of cerebral infarction and hemorrhage. Obstructive sleep apnea (OSA) is known to increase the risk of cerebrovascular disease. This study aimed to investigate the association between cerebral SVD and severity of OSA.

METHODS

A total of 170 patients were included from the patient registry at the present Sleep Center; these patients underwent both magnetic resonance imaging (MRI) of the brain and polysomnography (PSG) for suspected OSA. The presence and burden of white matter hyperintensities (WMHs), asymptomatic lacunar infarctions (ALIs), cerebral microbleeds (CMBs), and perivascular spaces (PVSs) were determined by MRI, and their relationships with the apnea-hypopnea index (AHI), as determined by PSG, were investigated.

RESULTS

Among the 170 patients, 25 (14.7%) had high-grade WMHs, 21 (12.4%) had ALIs, 21 (12.4%) had CMBs, and 34 (20.0%) had high-grade PVSs. In the multivariable analysis, after adjusting for factors including age, sex, and other variables for which p <0.1 in univariable analysis (hypertension, diabetes mellitus, previous stroke, minimal SaO₂ and arousal index), moderate-to-severe OSA was associated with high-grade WMHs (odds ratio [OR] 4.72; 95% confidence interval [CI] 1.14-19.47), CMBs (OR 3.47; 95% CI 0.89-15.18), or high-grade PVSs (OR 3.64; 95% CI 1.02-13.01), but not with ALIs. The total SVD score was independently associated with increased AHI (p = 0.017), particularly in patients with moderate-to-severe OSA (β [standard error] = 0.448 (0.204), p = 0.030].

CONCLUSION

Moderate-to-severe OSA is positively associated with multiple indicators of cerebral SVD, including WMHs, CMBs, and PVSs.

Sleep apnea syndrome in endocrine clinics

Obstructive sleep apnea syndrome (OSAS) is a chronic condition with a high prevalence (up to 7 % of the general population) characterized by frequent episodes of upper airway collapse while sleeping. Left untreated, OSAS can cause severe complications, including systemic hypertension, cardiovascular disease, stroke, and abnormal glucose metabolism. This review aims to summarize the close links between OSAS, endocrinology, and metabolism. In patients with metabolic syndrome, OSAS is an independent risk factor for the onset of type 2 diabetes and a worsening glycemic control. The accumulation of adipose tissue in the neck and limited chest wall dynamics, hypoxia, and local micro-inflammation link visceral obesity closely with OSAS. There is now an abundance of convincing data indicating that promoting lifestyle changes, improving sleep hygiene, and adjusting diet can ameliorate both metabolic syndrome and OSAS, especially in obese patients. The incidence of OSAS in acromegaly is high, though GH treatments seem to be unrelated to the onset of apnea in GH-deficient individuals. Prospective studies have suggested an association between hypertension and OSAS because intermittent nocturnal hypoxia prompts an increase in sympathetic tone, endothelial dysfunction, and vascular inflammation: aldosterone excess may have a pathophysiological role, and some authors have reported that treating OSAS leads to a modest, but significant, reduction in blood pressure.

Obstructive Sleep Apnoea and Vascular Disease in Patients with Type 2 Diabetes

Obstructive sleep apnoea (OSA) is common and is associated with many vascular risk factors, such as hypertension, insulin resistance, albuminuria, dyslipidaemia, increased inflammation and endothelial dysfunction. Epidemiological studies have shown that OSA is associated with increased cardiovascular disease (CVD) and that continuous positive airway pressure (CPAP) might reduce CVD events in patients with OSA. In addition, OSA has also been shown to be associated with albuminuria, chronic kidney disease, a wide range of ocular diseases and peripheral neuropathy. Considering that CVD and microvascular complications are major contributors to the morbidity, mortality and the economic burden of diabetes and that OSA is common in patients with type 2 diabetes (T2D), it is important to understand the role of OSA in the development and/or progression of vascular disease in patients with T2D and to explore the impact of CPAP on diabetes-related vascular outcomes. The purpose of this article is to review the evidence for the relationship and impact of OSA on vascular disease and vascular risk factors particularly in patients with T2D.

Novel therapeutics for type 2 diabetes: insulin resistance

Insulin resistance (IR) plays an important role in the pathogenesis of type 2 diabetes (T2D) and cardiovascular disease. Hence improving IR is a major target of treatment in patients with T2D. Obesity and lack of exercise are major causes of IR. However, recent evidence implicates sleep disorders and disorders of the circadian rhythm in the pathogenesis of IR. Weight loss and lifestyle changes are the cornerstone and most effective treatments of IR, but adherence and patient's acceptability are poor. Bariatric surgery results in significant and sustainable long-term weight loss associated with beneficial impact on IR and glucose metabolism, making this an attractive treatment option for patients with T2D. Currently available pharmacological options targeting IR (such as metformin and thiazolidinediones) do not maintain glycaemic measures within targets long term and can be associated with significant side effects. Over the last two decades, many pharmacological agents targeting different aspects of the insulin signalling pathway were developed to improve IR, but only a minority reached clinical trials. Such treatments need to be specific and reversible as many of the components of the insulin signalling pathway are involved in other cellular functions such as apoptosis. Recent evidence highlighted the role of circadian rhythm and sleep-related disorders in the pathogenesis of IR. In this article, we review the latest developments in the pharmacological and non-pharmacological interventions targeting IR including bariatric surgery. We will also review the role of circadian rhythm and sleep-related disorders in the development and treatment of IR.

Diabetes, sleep apnea, obesity and cardiovascular disease: Why not address them together?

Obesity, sleep apnea, diabetes and cardiovascular diseases are some of the most common diseases encountered by the worldwide population, with high social and economic burdens. Significant emphasis has been placed on obtaining blood pressure, body mass index, and placing importance on screening for signs and symptoms pointing towards cardiovascular disease. Symptoms related to sleep, or screening for sleep apnea has been overlooked by cardiac, diabetic, pulmonary and general medicine clinics despite recommendations for screening by several societies. In recent years, there is mounting data where obesity and obstructive sleep apnea sit at the epicenter and its control can lead to improvement and prevention of diabetes and cardiovascular complications. This editorial raises questions as to why obstructive sleep apnea screening should be included as yet another vital sign during patient initial inpatient or outpatient visit.