The Effect of OSA Therapy on Glucose Metabolism: It's All about CPAP Adherence!

The effects of continuous positive airway pressure and mandibular advancement therapy on metabolic outcomes of patients with mild obstructive sleep apnea: a randomized controlled study

BACKGROUND

Moderate and severe obstructive sleep apnea (OSA) have been independently associated with dyslipidemia. The results of metabolic improvement with continuous positive airway pressure (CPAP) have been controversial. Less evidence exists regarding this issue in mild OSA. A current treatment for mild OSA is mandibular advancement device (MAD) therapy, but its effectiveness on the metabolic profile needs to be compared with CPAP. The purpose of this study was to compare MAD vs CPAP vs no treatment on the metabolic profile during 6 and 12 months of follow-up in patients with mild OSA.

METHODS

The inclusion criteria were patients with mild OSA, both genders, ages 18 to 65 years, and body mass index (BMI) of < 35 Kg/m². Patients were randomized in 3 groups (CPAP, MAD, and control). The evaluations included physical examination, metabolic profile, and full polysomnography at baseline, 6 months, and 12 months of follow-up.

RESULTS

Seventy-nine patients with mild OSA were randomized in three treatment groups, with mean age (± SD) of 47 ± 9 years, 54% men, and AHI 9.5 ± 2.9 events/h. MAD and CPAP reduced AHI at 6 and 12 months compared to the control group. MAD adherence was higher than CPAP at 6 and 12 months. Despite lower adherence compared to MAD, CPAP was more effective in reducing total cholesterol over 12 months (baseline 189.3 ± 60.2 mg/dl to 173.4 ± 74.3 mg/dl) and low-density lipoprotein cholesterol (LDL-c, baseline 112.8 ± 54.9 mg/dl to 94.5 ± 67.4 mg/dl).

CONCLUSIONS

After 1 year of treatment, CPAP was superior to MAD in reducing total cholesterol and LDL-c in patients with mild OSA.

Use of the WatchPAT to detect occult residual sleep-disordered breathing in patients on CPAP for obstructive sleep apnea

STUDY OBJECTIVES

To determine the accuracy of the apnea-hypopnea index (AHI) as measured by continuous positive airway pressure (CPAP) machines by simultaneously employing a home sleep apnea testing device (WatchPAT 200, Itamar Medical, Israel [WPAT]) in patients suspected of having residual sleep-disordered breathing (SDB).

METHODS

Patients with new, recurrent, or worsening signs, symptoms, or comorbidities associated with obstructive sleep apnea underwent home sleep apnea testing using WPAT while simultaneously using CPAP at their usual prescribed settings. CPAP AHI and WPAT AHI, respiratory disturbance index, and oximetry readings were then compared.

RESULTS

We identified an elevated AHI with WPAT testing in nearly half of patients with clinically suspected residual SDB and a normal CPAP AHI. WPAT detected additional respiratory events as well, including rapid eye movement-related apneas, respiratory effort-related arousals, and hypoxemia.

CONCLUSIONS

WPAT AHI was significantly higher than simultaneous CPAP AHI in nearly half of those patients with clinically suspected residual SDB being treated with CPAP. Additional respiratory disturbances, including rapid eye movement-related respiratory events, respiratory effort-related arousals, and hypoxemia, were elucidated only with the use of the WPAT. Residual SDB may have potential clinical consequences, including reduced CPAP adherence, ongoing hypersomnolence, and other health-related sequelae. Simultaneous WPAT testing of patients with a normal CPAP AHI may represent a valuable tool to detect clinically suspected residual SDB or to ensure adequate treatment in high-risk patients with obstructive sleep apnea in general.

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.

A Population-Based Study of the Bidirectional Association Between Obstructive Sleep Apnea and Type 2 Diabetes in Three Prospective U.S. Cohorts

OBJECTIVE

Multiple lines of evidence support a complex relationship between obstructive sleep apnea (OSA) and diabetes. However, no population-based study has evaluated the potential bidirectional association between these two highly prevalent disorders.

RESEARCH DESIGN AND METHODS

We followed 146,519 participants from the Nurses' Health Study (NHS; 2002-2012), Nurses' Health Study II (NHSII; 1995-2013), and Health Professionals Follow-up Study (HPFS; 1996-2012) who were free of diabetes, cardiovascular disease, and cancer at baseline. Cox proportional hazards models were used to estimate hazard ratios (HRs) for developing diabetes according to OSA status. In parallel, we used similar approaches to estimate risk of developing OSA according to diabetes status among 151,194 participants free of OSA, cardiovascular disease, and cancer at baseline. In all three cohorts, diagnoses of diabetes and OSA were identified by validated self-reports.

RESULTS

Similar results were observed across the three cohorts. In the pooled analysis, 9,029 incident diabetes cases were identified during follow-up. After accounting for potential confounders, the HR (95% CI) for diabetes was 2.06 (1.86, 2.28) comparing those with versus without OSA. The association was attenuated but remained statistically significant after further adjusting for waist circumference and BMI (HR 1.37 [95% CI 1.24, 1.53]), with the highest diabetes risk observed for OSA concomitant with sleepiness (1.78 [1.13, 2.82]). In the second analysis, we documented 9,364 incident OSA cases during follow-up. Compared with those without diabetes, the multivariable HR (95% CI) for OSA was 1.53 (1.32, 1.77) in individuals with diabetes. Adjustment for BMI and waist circumference attenuated the association (1.08 [1.00, 1.16]); however, an increased risk was observed among those with diabetes who used insulin compared with those without diabetes (1.43 [1.11, 1.83]), particularly among women (1.60 [1.34, 1.89]).

CONCLUSIONS

OSA is independently associated with an increased risk of diabetes, whereas insulin-treated diabetes is independently associated with a higher risk of OSA, particularly in women. Clinical awareness of this bidirectional association may improve prevention and treatment of both diseases. Future research aimed at elucidating the mechanisms that underlie each association may identify novel intervention targets.

Poor Sleep and Obesity: Concurrent Epidemics in Adolescent Youth

Poor sleep and obesity are both extraordinarily common in the US adolescent population and often occur simultaneously. This review explores the links between obesity and sleep, outlining what is known about the relationships between sleep characteristics, obesity, and cardiometabolic risk factors in youth. Sleep duration is less than optimal in teens, and decreases as age increases. This is detrimental to overall well-being and is associated with obesity in children, adolescents, and young adults. Accordingly, inadequate sleep duration is associated with poor diet quality, decreased insulin sensitivity, hyperglycemia, and prevalent cardiometabolic risk factors. Evidence suggests that poor sleep quality and altered circadian timing characterized by a preferred later sleep onset, known as "adolescent chronotype," contributes to shortened sleep duration. Obstructive sleep apnea (OSA) occurs more frequently among youth with obesity, and is associated with autonomic nervous system activity promoting higher blood pressure, increased markers of cardiovascular disease risk, and insulin resistance. While there is a clear association between OSA and type 2 diabetes in adults, whether or not this association is prevalent in youth is unclear at this time. Interventions to improve both sleep duration and quality, and obesity in adolescents are scarce and more evidence is needed to determine if such interventions can improve obesity-related health outcomes.

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.