Effect of CPAP on insulin resistance and HbA1c in men with obstructive sleep apnoea and type 2 diabetes. Thorax

Churchill College, Cambridge, England, United Kingdom
Thorax (Impact Factor: 8.29). 11/2007; 62(11):969-74. DOI: 10.1136/thx.2006.074351
Source: PubMed


The effects of continuous positive airway pressure (CPAP) for obstructive sleep apnoea (OSA) on insulin resistance are not clear. Trials have found conflicting results and no appropriate control groups have been used.
Forty-two men with known type 2 diabetes and newly diagnosed OSA (>10 dips/h in oxygen saturation of >4%) were randomised to receive therapeutic (n = 20) or placebo CPAP (n = 22) for 3 months. Baseline tests were performed and repeated after 3 months. The study was double blind.
Results are expressed as mean (SD). CPAP improved the Epworth sleepiness score significantly more in the therapeutic group than in the placebo group (-6.6 (4.5) vs -2.6 (4.9), p = 0.01). The maintenance of wakefulness test improved significantly in the therapeutic group but not in the placebo group (+10.6 (13.9) vs -4.7 (11.8) min, p = 0.001). Glycaemic control and insulin resistance did not significantly change in either the therapeutic or placebo groups: HbA1c (-0.02 (1.5) vs +0.1 (0.7), p = 0.7, 95% CI -0.6% to +0.9%), euglycaemic clamp (M/I: +1.7 (14.1) vs -5.7 (14.8), p = 0.2, 95% CI -1.8 to +0.3 l/kg/min(1000)), HOMA-%S (-1.5 (2.3) vs -1.1 (1.8), p = 0.2, 95% CI -0.3% to +0.08%) and adiponectin (-1.1 (1.2) vs -1.1 (1.3), p = 0.2, 95% CI -0.7 to +0.6 microg/ml). Body mass index, bioimpedance and anthropometric measurements were unchanged. Hours of CPAP use per night were 3.6 (2.8) in the treatment group and 3.3 (3.0) in the placebo group (p = 0.8). There was no correlation between CPAP use and the measures of glycaemic control or insulin resistance.
Therapeutic CPAP does not significantly improve measures of glycaemic control or insulin resistance in men with type 2 diabetes and OSA.

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Available from: John R Stradling, Jan 13, 2014
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    • "Two studies were excluded, because one of them had no information regarding HbA1c or insulin sensitivity and the subjects in the other did not have type 2 diabetes. Hence, a total of six studies met the inclusion criteria [12, 14, 15, 18, 19, 24]. The characteristics of the six studies included in the meta-analysis are summarised in Table I. "
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    ABSTRACT: Introduction Obstructive sleep apnoea (OSA) is a prevalent disorder characterised by repetitive upper-airway obstruction during sleep, and it is associated with type 2 diabetes. Continuous positive airway pressure (CPAP) is the primary treatment for OSA. Prior studies investigating whether CPAP can improve insulin resistance or glucose control in OSA patients have resulted in conflicting findings. This meta-analysis investigated whether CPAP treatment could improve glucose metabolism and insulin resistance in patients with OSA and type 2 diabetes. Material and methods We performed a systematic literature search using Medline, Cochrane, EMBASE, and Google Scholar databases for randomised controlled prospective studies that investigated the effect of CPAP on glycaemic control or insulin sensitivity in subjects with type 2 diabetes. Results The combined standard (STD) paired difference in mean change in the levels of glycated haemoglobin (HbA1c) was –0.073% (standard error (SE): 0.126), indicating that CPAP treatment did not alter HbA1c levels. The combined STD paired difference in mean change of insulin sensitivity was observed as 0.552 µmol/kg • min (SE = 0.196) and indicated insulin sensitivity significantly increased with CPAP treatment (p = 0.005). Conclusions We found that the CPAP treatment did not alter HbA1c levels but did significantly improve insulin resistance, indicating treating OSA can positively impact the symptoms of type 2 diabetes.
    Full-text · Article · Aug 2014 · Archives of Medical Science
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    • "Finally, there are two randomized placebo-controlled studies that had a sham CPAP (placebo CPAP at a sub-therapeutic level) arm to assess the effects of CPAP on glucose homeostasis. In one of these, West and colleagues [45] reported no improvement in HbA1c and insulin sensitivity in 42 men with type 2 diabetes and with baseline 4% oxygen-desaturation index (ODI) >10 epiepisodes/h , which however as a single variable without any other respiratory and other outcome measures does not prove the presence of moderate or severe OSA. In the other one, Hoyos and colleagues [46] conducted a 12-week CPAP vs. sham CPAP trial in 65 non-diabetes men (17 had an impaired glucose tolerance) with OSA (mean apnoea-hypopnea index AHI 39.9 episodes/h), and found no change in insulin sensitivity. "
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    ABSTRACT: An increasing body of evidence suggests that obstructive sleep apnoea (OSA) is independently associated with an increased risk of cardiovascular disease, glucose intolerance, and deteriorations in glycaemic control. Despite the knowledge of a multifactorial pathogenesis of long-term diabetes complications, there is a paucity of information on impact of comorbidities associated with chronic intermittent hypoxemia on development and progression of chronic diabetes complications. This review explores the clinical and scientific overlap of OSA and type 2 diabetes mellitus (T2DM) and its possible impact on the development and progression of diabetes macrovascular and microvascular complications. Multiple prospective observational cohort studies have demonstrated that OSA significantly increases the risk of cardiovascular disease independent of potential confounding risk factors. The current evidence further suggests that OSA with concurrent T2DM is associated with an increased risk of oxidative stress-induced damage of vulnerable endothelial and mesangial cells and peripheral nerves. Further studies are needed to validate the impact of OSA treatment on diabetes micro- and macrovascular complications. Since it is presently still unknown whether OSA treatment may provide a diabetes-modifying intervention that could delay or halt the progression of chronic diabetes complications, the emphasis is on early diagnosis and satisfactory treatment of both OSA and T2DM.
    Full-text · Article · May 2014 · Diabetes Research and Clinical Practice
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    • "Furthermore, the effect of CPAP treatment on glucose levels is variable, and improving insulin resistance in non-obese patients in a short term has also been documented [36]. Although positive effect has been shown in observational studies, randomized controlled studies [37] have shown no changes in insulin resistance after treatment with CPAP. Although diabetes is correlated with visceral and abdominal obesity, glucose abnormalities have also been documented in non-obese patients with OSA [20,38]. "
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    ABSTRACT: Obstructive sleep apnea (OSA) is a clinical picture characterized by repeated episodes of obstruction of the upper airway. OSA is associated with cardiovascular risk factors, some of which are components of metabolic syndrome (MS). First, determine the prevalence of MS in patients with OSA visited in sleep clinic. Second, evaluate whether there is an independent association between MS components and the severity of OSA. Patients with clinical suspicion of OSA were evaluated by polysomnography. Three groups were defined according to apnea hypoapnea index (AHI): no OSA (AHI <5), mild-moderate (AHI≥ 5 ≤30), and severe (AHI> 30). All patients were determined in fasting blood glucose, total cholesterol, HDL cholesterol, triglycerides and insulin. MS was defined according to criteria of National Cholesterol Education Program (NCEP). A total of 141 patients (mean age 54 ± 11 years) were evaluated. According to AIH, 25 subjects had no OSA and 116 had OSA (41mild-moderate and 75 severe). MS prevalence ranged from 43-81% in OSA group. Also, a significant increase in waist circumference, triglycerides, glucose, blood pressure levels, and a decrease in HDL cholesterol levels was observed in more severe OSA patients. All polysomnographic parameters correlated significantly with metabolic abnormalities. After a multiple regression analysis, abdominal obesity (p <0.02), glucose (p <0.01) and HDL cholesterol (p <0.001) were independently associated with OSA. Our findings show high prevalence of MS in OSA, especially in severe group. A significant association between OSA and some of the components of MS was found in Spanish population.
    Full-text · Article · Oct 2013 · The Open Respiratory Medicine Journal
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