CPAP therapy for patients with sleep apnea and type 2 diabetes mellitus improves control of blood pressure

Effects of continuous positive airway pressure therapy on glucose metabolism in patients with obstructive sleep apnoea and type 2 diabetes: a systematic review and meta-analysis

Obstructive sleep apnoea is a highly prevalent chronic disorder and has been shown to be associated with disturbed glucose metabolism and type 2 diabetes. However, the evidence from individual clinical trials on the effect of continuous positive airway pressure (CPAP) treatment on glycaemic control in patients with co-existing obstructive sleep apnoea and type 2 diabetes remains controversial. A systematic review of randomised controlled trials assessing the effect of CPAP on glycaemic control in patients with obstructive sleep apnoea and type 2 diabetes was conducted using the databases MEDLINE, Embase, Cochrane and Scopus up to December 2022. Meta-analysis using a random-effect model was performed for outcomes that were reported in at least two randomised controlled trials. From 3031 records screened, 11 RCTs with a total of 964 patients were included for analysis. CPAP treatment led to a significant reduction in haemoglobin A1c (HbA1c) (mean difference -0.24%, 95% CI -0.43- -0.06%, p=0.001) compared to inactive control groups. Meta-regression showed a significant association between reduction in HbA1c and hours of nightly CPAP usage. CPAP therapy seems to significantly improve HbA1c and thus long-term glycaemic control in patients with type 2 diabetes and obstructive sleep apnoea. The amount of improvement is dependent on the hours of usage of CPAP and thus optimal adherence to CPAP should be a primary goal in these patients.

Effect of Continuous Positive Airway Pressure on Glucose and Lipid Profiles in Patients With Obstructive Sleep Apnoea: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND AND AIM

Continuous Positive Airway Pressure (CPAP) is the most effective therapy for symptomatic obstructive sleep apnoea (OSA). However, uncertainty remains about the effectiveness of CPAP in improving OSA-related metabolic dysregulation. This meta-analysis of randomized controlled trials (RCTs) aimed to investigate whether CPAP, compared to other control treatments, could improve glucose or lipid metabolism in OSA patients.

METHODS

Relevant articles were searched in three different databases (MEDLINE, EMBASE and Web of Science) from inception to 6th Feb 2022 through specific search terms and selection criteria.

RESULTS

From a total of 5553 articles, 31 RCTs were included. CPAP modestly improved insulin sensitivity as determined by mean fasting plasma insulin and Homeostasis Model Assessment of Insulin Resistance reduction of 1.33mU/L and 0.287, respectively. In subgroup analyses pre-diabetic/type 2 diabetic patients as well as those with sleepy OSA showed a greater response to CPAP. Regarding lipid metabolism, CPAP was associated with a mean total cholesterol reduction of 0.064mmol/L. In subgroup analyses, the benefit was higher in patients that showed more severe OSA and oxygen desaturations at the baseline sleep study as well as in younger and obese subjects. Neither glycated haemoglobin nor triglycerides, HDL- and LDL-cholesterol were reduced by CPAP.

CONCLUSION

CPAP treatment may improve insulin sensitivity and total cholesterol levels in OSA patients but with low effect size. Our results suggest that CPAP does not substantially improve metabolic derangements in an unselected OSA population, but the effect may be higher in specific subgroups of OSA patients.

Role of chemosensitivity: Possible pathophysiological mediator of obstructive sleep apnea and type 2 diabetes

Obstructive sleep apnea (OSA) and type 2 diabetes show some mutual promotion of disease development. Variation in chemosensitivity is a key contributor to the pathophysiological mechanisms causing OSA and type 2 diabetes. According to studies conducted thus far, people with OSA or type 2 diabetes may have higher chemoreflex levels, but it is challenging to identify the precise changes because of variations in participant characteristics, the severity of the disease at the time of recruitment, and the small sample sizes in each study. Lowering chemosensitivity may also be viewed as a new issue for individuals with OSA and type 2 diabetes who require personalized care. The purpose of this review was to give an overview of chemosensitivity changes in OSA and glucose metabolism, as well as prospective therapeutic treatments for patients with OSA and type 2 diabetes.

Influence of continuous positive airway pressure on lipid profiles of obstructive sleep apnea: A systematic review and meta-analysis

BACKGROUND

To investigate the influence of continuous positive airway pressure (CPAP) on lipid profiles of the patients with obstructive sleep apnea (OSA) in this meta-analysis.

METHODS

Relevant studies reporting the correlation between CPAP and lipid profiles of OSA patients were searched in Pubmed, Cochrane Library and Embase before January 1, 2021. Data of eligible studies were extracted and analyzed using the fixed-effect or random-effect model. Standard mean difference (SMD) and 95% confidence interval (95% CI) were calculated to assess such influence. Subgroup analysis based on CPAP duration was further performed. STATA 12.0 was used in this meta-analysis.

RESULTS

A total of 12 independent randomized controlled studies involved 1129 OSA patients were recruited in this meta-analysis. The analyzed lipid profiles included total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL) and high density lipoprotein (HDL). CPAP was not correlated to TC (SMD = -0.07, 95% CI = -0.33 to 0.19), TG (SMD = -0.01, 95% CI = -0.19 to 0.17), LDL (SMD = -0.01, 95% CI = -0.23 to 0.21) and HDL (SMD = 0.10, 95% CI = -0.03 to 0.22) in OSA patients. Moreover, CPAP duration (=12 weeks; >12 weeks; <12 weeks) also did not influence lipid profiles of OSA patients as well.

CONCLUSIONS

Regardless of the treatment in CPAP duration, it doses does not influence lipid profiles of OSA patients, including TC, TG, LDL and HDL. The results are inconsistent with previous findings, which should be further validated in the multi-center, long-term randomized controlled trials.

American Association of Clinical Endocrinology Clinical Practice Guideline: Developing a Diabetes Mellitus Comprehensive Care Plan-2022 Update

OBJECTIVE

The objective of this clinical practice guideline is to provide updated and new evidence-based recommendations for the comprehensive care of persons with diabetes mellitus to clinicians, diabetes-care teams, other health care professionals and stakeholders, and individuals with diabetes and their caregivers.

METHODS

The American Association of Clinical Endocrinology selected a task force of medical experts and staff who updated and assessed clinical questions and recommendations from the prior 2015 version of this guideline and conducted literature searches for relevant scientific papers published from January 1, 2015, through May 15, 2022. Selected studies from results of literature searches composed the evidence base to update 2015 recommendations as well as to develop new recommendations based on review of clinical evidence, current practice, expertise, and consensus, according to established American Association of Clinical Endocrinology protocol for guideline development.

RESULTS

This guideline includes 170 updated and new evidence-based clinical practice recommendations for the comprehensive care of persons with diabetes. Recommendations are divided into four sections: (1) screening, diagnosis, glycemic targets, and glycemic monitoring; (2) comorbidities and complications, including obesity and management with lifestyle, nutrition, and bariatric surgery, hypertension, dyslipidemia, retinopathy, neuropathy, diabetic kidney disease, and cardiovascular disease; (3) management of prediabetes, type 2 diabetes with antihyperglycemic pharmacotherapy and glycemic targets, type 1 diabetes with insulin therapy, hypoglycemia, hospitalized persons, and women with diabetes in pregnancy; (4) education and new topics regarding diabetes and infertility, nutritional supplements, secondary diabetes, social determinants of health, and virtual care, as well as updated recommendations on cancer risk, nonpharmacologic components of pediatric care plans, depression, education and team approach, occupational risk, role of sleep medicine, and vaccinations in persons with diabetes.

CONCLUSIONS

This updated clinical practice guideline provides evidence-based recommendations to assist with person-centered, team-based clinical decision-making to improve the care of persons with diabetes mellitus.

Effect of different treatments for obstructive sleep apnoea on blood pressure

OBJECTIVE

Obstructive sleep apnoea (OSA) is a common cause of secondary hypertension. This network meta-analysis (NMA) assessed the effect of different OSA treatments on lowering blood pressure.

METHODS

PubMed, EMBASE, Web of Science, and Cochrane Library databases were searched for relevant randomized controlled trials. The search strategies included the concepts of OSA, blood pressure, hypertension, and blood pressure-reducing treatments without language or data restriction (from inception to 1 June 2021). The outcomes included office SBP, office DBP, daytime SBP (dSBP) and DBP (dDBP), and night-time SBP (nSBP) and DBP (nDBP). A Bayesian network meta-analysis was performed, and mean differences with 95% credibility intervals were calculated.

RESULTS

We reviewed 49 randomized controlled trials involving 4893 patients and the following interventions: continuous positive-airway pressure (CPAP), mandibular advancement devices, nocturnal supplemental oxygen, surgery, β-blocker, angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin receptor blockers (ARBs), renal sympathetic denervation (RDN), mineralocorticoid receptor antagonists (MRAs), calcium channel blockers. MRAs were significantly associated with blood pressure reduction followed by ACEI/ARB. RDN could reduce office SBP, office DBP, 24-h SBP, 24-h DBP, dSBP, and dDBP. CPAP also demonstrated modest blood pressure lowering.

CONCLUSION

MRAs and ACEIs/ARBs can reduce blood pressure effectively in patients with OSA. RDN is a novel hypertension treatment that lowered blood pressure in such patients. CPAP was associated with mild but stable blood pressure reduction, and it might be helpful as an adjunctive therapy in OSA patients with hypertension.

REVIEW REGISTRATION

This systematic review and meta-analysis was registered in PROSPERO: CRD42021240891.

Diabetes mellitus and cardiovascular risk: an update of the recommendations of the Diabetes and Cardiovascular Disease Working Group of the Spanish Society of Diabetes (SED, 2021)

This document is an update to the clinical practice recommendations for the management of cardiovascular risk factors (CVRF) in diabetes mellitus. The consensus has been developed by a multidisciplinary team made up of members of the Cardiovascular Risk Group of the Spanish Diabetes Society (SED). The work is a necessary update as, since the last review three years ago, there have been many clinical trials that have studied the cardiovascular outcomes of numerous drugs in the diabetic population. We believe that this guideline update may be of interest to all clinicians treating patients with diabetes.

Obstructive sleep apnoea and 12-month weight loss in adults with class 3 obesity attending a multidisciplinary weight management program

BACKGROUND

Although there is a strong association between obesity and obstructive sleep apnoea (OSA), the effects of OSA and CPAP therapy on weight loss are less well known. The aim of this study in adults with class 3 obesity attending a multidisciplinary weight management program was to assess the relationship between OSA and CPAP usage, and 12-month weight change.

METHODS

A retrospective cohort study of all patients commencing an intensive multidisciplinary publicly funded weight management program in Sydney, Australia, between March 2018 and March 2019. OSA was diagnosed using laboratory overnight sleep studies. Demographic and clinical data, and use of CPAP therapy was collected at baseline and 12 months. CPAP use was confirmed if used ≥4 h on average per night on download.

RESULTS

Of the 178 patients who joined the program, 111 (62.4 %) completed 12 months in the program. At baseline, 63.1 % (n=70) of patients had OSA, of whom 54.3 % (n=38) were using CPAP. The non-OSA group had more females compared to the OSA with CPAP group and OSA without CPAP group (90.2 % vs. 57.9 % and 62.5 %, respectively; p=0.003), but there were no significant baseline differences in BMI (50.4±9.3 vs. 52.1±8.7 and 50.3±9.5 kg/m², respectively; p=0.636). There was significant weight loss across all three groups at 12 months. However, there were no statistically significant differences across groups in the percentage of body weight loss (OSA with CPAP: 6.3±5.6 %, OSA without CPAP: 6.8±6.9 %, non-OSA: 7.2±6.5 %; p=0.844), or the proportion of patients who achieved ≥5 % body weight loss (OSA with CPAP: 57.9 %, OSA without CPAP: 59.4 %, non-OSA: 65.9 %; p=0.743). In patients with T2DM, there was a significant reduction in HbA1c from baseline to 12 months (7.8±1.7 % to 7.3±1.4 %, p=0.03), with no difference between groups (p=0.997).

CONCLUSIONS

This multidisciplinary weight management program resulted in significant weight loss at 12 months, regardless of OSA diagnosis or CPAP use in adults with class 3 obesity. Larger studies are needed to further investigate the effects of severity of OSA status and CPAP use in weight management programs. Until completed, this study suggests that the focus should remain on implementing lifestyle changes and weight management regardless of OSA status.

Association of continuous positive airway pressure adherence with complications in patients with type 2 diabetes and obstructive sleep apnea

STUDY OBJECTIVES

To explore the association of continuous positive airway pressure (CPAP) adherence with clinical outcomes in patients with type 2 diabetes and obstructive sleep apnea in a real-world setting.

METHODS

This was a retrospective study of patients with type 2 diabetes diagnosed with obstructive sleep apnea between 2010 and 2017. CPAP adherence (usage for ≥ 4 h/night for ≥ 70% of nights) was determined from the first CPAP report following the polysomnography. Data including estimated glomerular filtration rate, hemoglobin A1c, systolic and diastolic blood pressure, lipid panel, and incident cardiovascular/peripheral vascular/cerebrovascular events were extracted from medical records. Mixed-effects linear regression modeling of longitudinal repeated measures within patients was utilized for continuous outcomes, and logistic regression modeling was used for binary outcomes. Models were controlled for age, sex, body mass index, medications, and baseline levels of outcomes.

RESULTS

Of the 1,295 patients, 260 (20.7%) were CPAP adherent, 318 (24.5%) were CPAP nonadherent, and 717 (55.3%) had insufficient data. The follow-up period was, on average, 2.5 (1.7) years. Compared to those who were CPAP nonadherent, those who were adherent had a significantly lower systolic blood pressure (β = -1.95 mm Hg, P = .001) and diastolic blood pressure (β = -2.33 mm Hg, P < .0001). Among the patients who were CPAP adherent, a 17% greater CPAP adherence was associated with a 2 mm Hg lower systolic blood pressure. Lipids, hemoglobin A1c, estimated glomerular filtration rate, and incident cardiovascular/peripheral vascular/cerebrovascular events were not different between the 2 groups.

CONCLUSIONS

Achieving CPAP adherence in patients with type 2 diabetes and obstructive sleep apnea was associated with significantly lower blood pressure. Greater CPAP use within patients who were adherent was associated with lower systolic blood pressure.

CITATION

Sheth U, Monson RS, Prasad B, et al. Association of continuous positive airway pressure adherence with complications in patients with type 2 diabetes and obstructive sleep apnea. J Clin Sleep Med. 2021;17(8):1563-1569.

Obstructive Sleep Apnea, Glucose Tolerance, and β-Cell Function in Adults With Prediabetes or Untreated Type 2 Diabetes in the Restoring Insulin Secretion (RISE) Study

OBJECTIVE

Obstructive sleep apnea (OSA) is associated with insulin resistance and has been described as a risk factor for type 2 diabetes. Whether OSA adversely impacts pancreatic islet β-cell function remains unclear. We aimed to investigate the association of OSA and short sleep duration with β-cell function in overweight/obese adults with prediabetes or recently diagnosed, treatment-naive type 2 diabetes.

RESEARCH DESIGN AND METHODS

Two hundred twenty-one adults (57.5% men, age 54.5 ± 8.7 years, BMI 35.1 ± 5.5 kg/m²) completed 1 week of wrist actigraphy and 1 night of polysomnography before undergoing a 3-h oral glucose tolerance test (OGTT) and a two-step hyperglycemic clamp. Associations of measures of OSA and actigraphy-derived sleep duration with HbA_1c, OGTT-derived outcomes, and clamp-derived outcomes were evaluated with adjusted regression models.

RESULTS

Mean ± SD objective sleep duration by actigraphy was 6.6 ± 1.0 h/night. OSA, defined as an apnea-hypopnea index (AHI) of five or more events per hour, was present in 89% of the participants (20% mild, 28% moderate, 41% severe). Higher AHI was associated with higher HbA_1c (P = 0.007). However, OSA severity, measured either by AHI as a continuous variable or by categories of OSA severity, and sleep duration (continuous or <6 vs. ≥6 h) were not associated with fasting glucose, 2-h glucose, insulin sensitivity, or β-cell responses.

CONCLUSIONS

In this baseline cross-sectional analysis of the RISE clinical trial of adults with prediabetes or recently diagnosed, untreated type 2 diabetes, the prevalence of OSA was high. Although some measures of OSA severity were associated with HbA_1c, OSA severity and sleep duration were not associated with measures of insulin sensitivity or β-cell responses.

Benefits of continuous positive airway pressure on glycaemic control and insulin resistance in patients with type 2 diabetes and obstructive sleep apnoea: A meta-analysis

AIM

To conduct a meta-analysis to determine the effects of continuous positive airway pressure (CPAP) treatment on glycaemic control and insulin resistance in patients with type 2 diabetes and obstructive sleep apnoea (OSA).

METHODS

A systematic search was made of the MEDLINE, SCOPUS, ISI Web of Science, Cochrane databases, and clinicaltrials.gov, without language restrictions. Randomized controlled trials on treatment of type 2 diabetes and OSA with CPAP, compared with sham CPAP or no CPAP, were reviewed. Studies were pooled to obtain standardized mean differences (SMDs), with 95% confidence intervals (CIs).

RESULTS

Seven trials (enrolling 691 participants) met the inclusion criteria. CPAP showed significant effects on glycated haemoglobin (HbA1c; SMD -0.32, 95% CI -0.60 to -0.03; P = 0.029), fasting glucose (SMD -0.39, 95% CI -0.76 to -0.02; P = 0.040), homeostatic model assessment of insulin resistance (HOMA-IR; SMD -1.05, 95% CI -1.91 to -0.19; P = 0.016), systolic blood pressure (SMD -1.18, 95% CI -2.29 to -0.07 mm Hg; P = 0.037), and diastolic blood pressure (SMD -1.29, 95% CI -2.48 to -0.09; P = 0.035).

CONCLUSIONS

Continuous positive airway pressure treatment significantly improved glycaemic control and insulin resistance, as shown by the decreased HbA1c levels, fasting glucose levels and HOMA-IR values in patients with type 2 diabetes and OSA.

Comparing the effects of supplemental oxygen therapy and continuous positive airway pressure on patients with obstructive sleep apnea: a meta-analysis of randomized controlled trials

BACKGROUND AND OBJECTIVE

Obstructive sleep apnea (OSA) is associated with hypertension, psychological impairment, neurocognitive dysfunction, and poor quality of sleep. Continuous positive airway pressure (CPAP) has been confirmed to effectively improve OSA, while the effects of supplemental oxygen therapy on OSA have still remained controversial. This meta-analysis aimed to compare the effects of supplemental oxygen therapy and CPAP on patients with OSA.

METHODS

PubMed, Cochrane library, EMBASE, and Web of Science databases were systematically searched from inception until April 2020. Randomized controlled trials (RCTs) that compared the effects of supplemental oxygen therapy and CPAP on patients with OSA were selected without language restriction.

RESULTS

In this meta-analysis, 8 RCTs that involved 887 patients were found eligible for further analyses. Pooled data showed that there was no significant difference in improving nocturnal oxygen saturation (SpO₂) level (95% confidence interval (CI) = - 1.17 to 1.53) or symptoms of depression (95%CI = - 0.69 to 1.19) between supplemental oxygen therapy and CPAP. Supplemental oxygen therapy was found less effective in reducing apnea-hypopnea index (AHI), time of SpO₂ < 90%, blood pressure, and improving quality of sleep compared with CPAP. A subgroup analysis based on flow rate of oxygen indicated that the effects of supplemental oxygen therapy on blood pressure significantly differed. Furthermore, an improvement in overall time of SpO₂ < 90% was correlated to duration of supplemental oxygen therapy.

CONCLUSIONS

CPAP is clinically effective for the treatment of patients with OSA. However, supplemental oxygen therapy can be cautiously used for improving nocturnal hypoxia and symptoms of depression when CPAP is not acceptable or not tolerated. Supplemental oxygen therapy is a promising option to alleviate partial disorders of OSA. Further studies need to focus on flow rate of oxygen and duration of supplemental oxygen therapy.

Obstructive sleep apnoea and cardiovascular disease: a literature review

As obesity becomes more common worldwide, the prevalence of obstructive sleep apnoea (OSA) continues to rise. Obstructive sleep apnoea is a well-known disorder that causes chronic intermittent hypoxia (CIH), which is considered a risk factor for atherosclerosis directly and indirectly. Ischaemic heart disease remains the leading cause of death. Most risk factors for atherosclerosis are well understood. However, other factors such as CIH are less well understood. Several studies have investigated the pathophysiology of CIH, attempting to uncover its link to atherosclerosis and to determine whether OSA treatment can be a therapeutic modality to modify the risk for atherosclerosis. In this article, we will review the pathophysiology of OSA as an independent risk factor for cardiovascular disease and discuss the most common markers that have been studied. We will also examine the potential impact of OSA management as a risk factor modifier on the reversibility of atherosclerosis.

Rationale and design of the Hyperglycemic Profiles in Obstructive Sleep Apnea (HYPNOS) trial

The Hyperglycemic Profiles in Obstructive Sleep Apnea (HYPNOS) randomized clinical trial was conducted in adults with type 2 diabetes and moderate-to-severe obstructive sleep apnea (OSA) to determine whether treatment with positive airway pressure (PAP) therapy is associated with improvements in glycemic measures. Participants were randomly assigned to PAP therapy with lifestyle counseling or lifestyle counseling alone. While observational and experimental evidence indicate that intermittent hypoxemia and recurrent arousals in OSA may alter glucose metabolism and worsen glycemic measures, the effect of treating OSA with PAP therapy on these measures in type 2 diabetes is uncertain. Adequately powered randomized clinical trials have yet to be performed to demonstrate whether PAP therapy for OSA in patients with type 2 diabetes can improve glycemic measures. The HYPNOS trial was designed to determine whether PAP therapy for OSA in patients with type 2 diabetes over 3 months leads to improvements in glycemic measures including glycemic variability (standard deviation) based on Dexcom G4 Platinum continuous glucose monitoring. Secondary objectives were to assess the effects of PAP therapy for OSA on measures of: (1) glycemic variability based on Abbott Freestyle Pro Libre continuous glucose monitoring; (2) point-of-care hemoglobin A1c (HbA1c); (3) degree of post-prandial hyperglycemia as determined by 7-point self-monitoring of blood glucose; (4) clinic and ambulatory blood pressure; and (5) endothelial function. The HYPNOS trial was designed to address gaps in our understanding of the effects of PAP therapy on glucose metabolism in adults with type 2 diabetes and moderate-to-severe OSA. Trial Registration: ClinicalTrials.gov Identifier NCT02454153.

Continuous Positive Airway Pressure Treatment, Glycemia, and Diabetes Risk in Obstructive Sleep Apnea and Comorbid Cardiovascular Disease

OBJECTIVE

Despite evidence of a relationship among obstructive sleep apnea (OSA), metabolic dysregulation, and diabetes, it is uncertain whether OSA treatment can improve metabolic parameters. We sought to determine effects of long-term continuous positive airway pressure (CPAP) treatment on glycemic control and diabetes risk in patients with cardiovascular disease (CVD) and OSA.

RESEARCH DESIGN AND METHODS

Blood, medical history, and personal data were collected in a substudy of 888 participants in the Sleep Apnea cardioVascular Endpoints (SAVE) trial in which patients with OSA and stable CVD were randomized to receive CPAP plus usual care, or usual care alone. Serum glucose and glycated hemoglobin A_1c (HbA_1c) were measured at baseline, 6 months, and 2 and 4 years and incident diabetes diagnoses recorded.

RESULTS

Median follow-up was 4.3 years. In those with preexisting diabetes (n = 274), there was no significant difference between the CPAP and usual care groups in serum glucose, HbA_1c, or antidiabetic medications during follow-up. There were also no significant between-group differences in participants with prediabetes (n = 452) or new diagnoses of diabetes. Interaction testing suggested that women with diabetes did poorly in the usual care group, while their counterparts on CPAP therapy remained stable.

CONCLUSIONS

Among patients with established CVD and OSA, we found no evidence that CPAP therapy over several years affects glycemic control in those with diabetes or prediabetes or diabetes risk over standard-of-care treatment. The potential differential effect according to sex deserves further investigation.

Obstructive sleep apnoea treatment and blood pressure: which phenotypes predict a response? A systematic review and meta-analysis

The treatment for obstructive sleep apnoea (OSA) with continuous positive airway pressure (CPAP) or mandibular advancement devices (MADs) is associated with blood pressure (BP) reduction; however, the overall effect is modest. The aim of this systematic review and meta-analysis of randomised controlled trials (RCTs) comparing the effect of such treatments on BP was to identify subgroups of patients who respond best to treatment.The article search was performed in three different databases with specific search terms and selection criteria. From 2289 articles, we included 68 RCTs that compared CPAP or MADs with either passive or active treatment. When all the studies were pooled together, CPAP and MADs were associated with a mean BP reduction of -2.09 (95% CI -2.78- -1.40) mmHg for systolic BP and -1.92 (95% CI -2.40- -1.43) mmHg for diastolic BP and -1.27 (95% CI -2.34- -0.20) mmHg for systolic BP and -1.11 (95% CI -1.82- -0.41) mmHg for diastolic BP, respectively. The subgroups of patients who showed a greater response were those aged <60 years (systolic BP -2.93 mmHg), with uncontrolled BP at baseline (systolic BP -4.14 mmHg) and with severe oxygen desaturations (minimum arterial oxygen saturation measured by pulse oximetry <77%) at baseline (24-h systolic BP -7.57 mmHg).Although this meta-analysis shows that the expected reduction of BP by CPAP/MADs is modest, it identifies specific characteristics that may predict a pronounced benefit from CPAP in terms of BP control. These findings should be interpreted with caution; however, they are particularly important in identifying potential phenotypes associated with BP reduction in patients treated for OSA.

Obstructive sleep apnea and dyslipidemia: from animal models to clinical evidence

Lipid metabolism deregulation constitutes the pathogenic basis for the development of atherosclerosis and justifies a high incidence of cardiovascular-related morbidity and mortality. Some data suggest that dyslipidemia may be associated with sleep-disordered breathing, mainly obstructive sleep apnea (OSA), due to alterations in fundamental biochemical processes, such as intermittent hypoxia (IH). The aim of this systematic review was to identify and critically evaluate the current evidence supporting the existence of a possible relationship between OSA and alterations in lipid metabolism. Much evidence shows that, during the fasting state, OSA and IH increase lipid delivery from the adipose tissue to the liver through an up-regulation of the sterol regulatory element-binding protein-1 and stearoyl-CoA desaturase-1, increasing the synthesis of cholesterol esters and triglycerides. In the postprandial state, lipoprotein clearance is delayed due to lower lipoprotein lipase activity, probably secondary to IH-up-regulation of angiopoietin-like protein 4 and decreased activity of the peroxisome proliferator-activated receptor alpha. Moreover, oxidative stress can generate dysfunctional oxidized lipids and reduce the capacity of high-density lipoproteins (HDL) to prevent low-density lipoprotein (LDL) oxidation. In the clinical field, several observational studies and a meta-regression analysis support the existence of a link between OSA and dyslipidemia. Although there is evidence of improved lipid profile after apnea-hypopnea suppression with continuous positive airway pressure (CPAP), the majority of the data come from observational studies. In contrast, randomized controlled trials evaluating the effects of CPAP on lipid metabolism present inconclusive results and two meta-analyses provide contradictory evidence.

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.

Factors influencing breath analysis results in patients with diabetes mellitus

Breath analysis is used to detect the composition of exhaled gas. As a quick and non-invasive detection method, breath analysis provides deep insights into the progression of various kinds of diseases, especially those with metabolism disorders. Abundant information on volatile compounds in diabetic patients has been studied in numerous articles in the literature. However, exhaled gas in diabetic patients can be altered by various complications. So far, little attention has been paid to this alteration. In our paper, we found that under air pollution conditions, diabetic patients exhale more nitric oxide. Diabetic patients with heart failure exhale more acetone than those without heart failure. After ¹³C-labeled glucose intake, patients infected with Helicobacter pylori exhaled more ¹³C and less ¹⁸O than those without infection. Exhalation with chronic kidney disease changes volatile organic compounds on a large scale. Diabetic patients with ketoacidosis exhale more acetone than those without ketoacidosis. Some specific volatile organic compounds also emanate from diabetic feet. By monitoring breath frequency, diabetic patients with obstructive sleep apnea syndrome exhibit a unique breath pattern and rhythm as compared with other diabetic patients, and sleep apnea is prevalent among diabetic patients. In addition to clinical findings, we analyzed the underlying mechanisms at the levels of molecules, cells and whole bodies, and provided suggestions for further studies.

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.

Association between nondipping pattern and EndoPAT signal in patients with mild obstructive sleep apnea

OBJECTIVE

To compare vascular endothelial function between dipping (D) and nondipping (ND) patterns in patients with and without mild obstructive sleep apnea (OSA) using EndoPAT, a test of reactive hyperemia used to assess peripheral vascular endothelial function.

METHODS

The sample consisted of individuals of both genders between 18 and 65 years of age with a body mass index (BMI) of ≤35 kg/m² and apnea/hypopnea index (AHI) of ≤15. The nondipping pattern was considered present when the dip of nocturnal blood pressure (NBP) was <10%. All of the sample underwent clinical and physical evaluation, full polysomnography, 24-hour ambulatory blood pressure monitoring, and EndoPAT evaluation. A generalized linear model was used for statistical analysis.

RESULTS

The sample comprised 120 individuals, 35 in the control group and 85 in the mild OSA group. Four groups were formed: Control-ND, Control-D, Mild OSA-ND, and Mild OSA-D according to nocturnal ABPM patterns. The frequency of nondipping was (34.1%) in the Mild OSA group and (17.1%) in the Control group (p = 0.07). The Mild OSA-ND group had a higher augmentation index (AIx) than the Mild OSA-D group. Regression analysis showed that male gender, higher age, and nondipping status were associated with these results, whereas oxygen desaturation index (ODI) and AHI did not. With respect to the reactive hyperemia index (RHI), the Mild OSA-D group had lower values compared to the Control-ND group, but an association with OSA was not confirmed in the regression model.

CONCLUSION

Nondipping status was associated with a worse augmentation index in both groups independently of AHI or oxygen desaturation index. Male gender, higher age, and nondipping status were associated with augmentation index. ClinicalTrials.gov Identifier: NCT01461486.

CPAP in patients with obstructive sleep apnea and type 2 diabetes mellitus: Systematic review and meta-analysis

INTRODUCTION

Obstructive sleep apnea hypopnea syndrome (OSAHS) is a prevalent condition across the world; it co-exists with others metabolic diseases, such as central obesity, dyslipidemia, and arterial hypertension. These associations increase the cardiovascular risk and mortality. Observational studies have reported a strength association between OSA and type 2 Diabetes Mellitus (T2DM) and continuous positive airway pressure (CPAP) is recommended for moderate to severe OSAHS.

OBJECTIVE

To summarize the evidence of CPAP in T2DM patients with OSAHS.

METHODS

A compressive search in Medline, Cochrane, Ovids, Epistemonikos, and DARE was performed. Two reviewers evaluated included studies, extracted data, carried out quality assessment and summarized the result. Pooled data was evaluated by meta-analysis and summaries of results and evidence grading were performed through the GRADE method.

RESULTS

Six randomized controlled trials (RCTs), including a total of 581 participants. Treatment with CPAP showed no effectiveness regarding changing glycated hemoglobin (HbA1c) levels at 12 or 24 weeks after treatment; (Mean difference= -0.10; Confidence interval -0.25 to 0.04) (GRADE: MODERATE). Subgroup analysis by adherence to CPAP (> 4 hours or < 4 hours) confirmed these results. Other indirect outcomes, such as change in fasting glucose levels, were similar in CPAP population and placebo.

DISCUSSION

This systematic review and meta-analysis evaluates the evidence regarding the efficacy of CPAP in patients with T2DM and OSAHS. In conclusion, CPAP does not improve glycemic control measure as HbA1c.

The Relationship between Diabetes-Related Complications and Obstructive Sleep Apnea in Type 2 Diabetes

This study explored the relationship between obstructive sleep apnea (OSA) and the presence of any diabetes-related complications in type 2 diabetes and whether this was mediated by hypertension. Secondly, the relationship between OSA severity and estimated glomerular filtration rate (eGFR) was investigated. A total of 131 patients participated. OSA was diagnosed using a home monitor, and severity was measured by apnea-hypopnea index (AHI) and oxygen desaturation index (ODI). OSA was found in 75.6% of the participants, 40.5% with moderate-to-severe degree. Any diabetes-related complications (retinopathy, neuropathy, nephropathy, or coronary artery disease) were present in 55.5%, and 70.2% of the participants had hypertension. Mediation analysis indicated that, compared to those with mild or no OSA, those with moderate-to-severe OSA were 3.05 times more likely to have any diabetes-related complications and that this relationship was mediated by the presence of hypertension. After adjusting for confounders, ODI (B = -0.036, p = 0.041), but not AHI, was significantly associated with lower eGFR. In conclusion, moderate-to-severe OSA was related to the presence of any diabetes-related complications in type 2 diabetes, and the relationship was mediated by hypertension. The severity of intermittent hypoxia was associated with lower eGFR. Whether OSA treatment will delay or reduce diabetes-related complications should be investigated.

Obstructive Sleep Apnea and Diabetes: A State of the Art Review

OSA is a chronic treatable sleep disorder and a frequent comorbidity in patients with type 2 diabetes. Cardinal features of OSA, including intermittent hypoxemia and sleep fragmentation, have been linked to abnormal glucose metabolism in laboratory-based experiments. OSA has also been linked to the development of incident type 2 diabetes. The relationship between OSA and type 2 diabetes may be bidirectional in nature given that diabetic neuropathy can affect central control of respiration and upper airway neural reflexes, promoting sleep-disordered breathing. Despite the strong association between OSA and type 2 diabetes, the effect of treatment with CPAP on markers of glucose metabolism has been conflicting. Variability with CPAP adherence may be one of the key factors behind these conflicting results. Finally, accumulating data suggest an association between OSA and type 1 diabetes as well as gestational diabetes. This review explores the role of OSA in the pathogenesis of type 2 diabetes, glucose metabolism dysregulation, and the impact of OSA treatment on glucose metabolism. The association between OSA and diabetic complications as well as gestational diabetes is also reviewed.