Obstructive sleep apnoea is independently associated with the metabolic syndrome but not insulin resistance state

Abstract

Obstructive sleep apnoea (OSA) is a cardio-metabolic disorder. Whether metabolic syndrome (MS), insulin resistance (IR) and albuminuria are independently associated with OSA is unclear, but defining the interactions between OSA and various cardiovascular (CV) risk factors independent of obesity facilitates the development of therapeutic strategies to mitigate their increased CV risks. We prospectively recruited 38 subjects with OSA and 41 controls. Anthropometric measurements, glucose, lipids, insulin and blood pressure (BP) were measured after an overnight fast. IR state was defined as homeostasis model assessment (HOMA) value >3.99 and MS diagnosed according to the International Diabetes Federation (IDF) criteria. Subjects with OSA were more obese, more insulin resistant, more hyperglycaemic, had higher Epworth score (measure of day time somnolence) and systolic blood pressure levels. The prevalence of MS was higher in OSA compared with non-OSA subjects (74% vs 24%, p < 0.001). The prevalence of microalbuminuria in both groups was negligible. Logistic regression adjusted for age, BMI and smoking showed that the patient with OSA was 5.9 (95% CI 2.0-17.6) times more likely to have MS than non-OSA patient. Triglyceride (p = 0.031), glucose (0.023) and Epworth score (0.003) values were independently associated with OSA after adjusting for BMI and other covariates whilst IR status was found not to be significant. Using the ROC curve analysis, we found that a waist circumference of >103 cm would predict MS in patients with OSA at 75-78% sensitivity and 61-64% specificity. The agreement between MS and IR state in this cohort is poor. Thus, OSA is associated with MS independent of obesity predominantly due to increased triglyceride, glucose and Epworth score values but not IR or microalbuminuria status. This observation suggests an alternative pathogenic factor mediating the increased cardiovascular risk in patients with OSA and MS, other than that due to IR. The independent link between Epworth score and MS in patients with OSA implicates the role of daytime sleepiness and chronic hypoxia as a potential mediator. Given the discordant between MS and IR state, measurement of waist is useful for predicting mainly MS but not insulin resistance status in patients with OSA. Appropriate pharmacological intervention targeting these independent factors is important in reducing the increased CV risks among patients with OSA.

Associations of exercise, sedentary time and insomnia with metabolic syndrome in Taiwanese older adults: A 1-year follow-up study

“…These factors are associated with adverse metabolic outcomes, which might partly explain higher rates of new development of MetS in older women than in old men in this study. Previous studies about the relationship between sleep and MetS have mostly focused on sleep duration and obstructive sleep apnea (9,(11)(12)(13)(14)(49)(50)(51). Less attention has been paid to the associations of insomnia with MetS.…”

Effects of Nasal Continuous Positive Airway Pressure Treatment on Oxidative Stress and Adiponectin Levels in Obese Patients with Obstructive Sleep Apnea

“…Similar results were found by Ip et al [27] and Punjabi et al [39], who identified the insulin resistance present in OSA as a factor independent from obesity. Gruber et al (2006) [40] reported that OSA is independently related with the metabolic syndrome, but not with insulin resistance, suggesting that in apneic patients factors other than insulin resistance would be the major ones responsible for the pathophysiology of the metabolic syndrome.…”

Insulin Resistance in Obstructive Sleep Apnoea Syndrome

“…Bazı çalışmalarda bu ilişki gösterilmiştir (8)(9)(10)(11)(12)(13). Bazı çalış-malarda ise; İR hastalığın kendisinden çok, bu hastalıkta görü-len obeziteye bağlanmaktadır (14)(15)(16)(17). Bu çalışmada OUAS'de obeziteden ve santral obeziteden bağımsız İD varlığı saptandı.…”