An Update on Obstructive Sleep Apnea and the Metabolic Syndrome
An Update on Obstructive Sleep Apnea and the Metabolic Syndrome
Purpose of Review: Patients with obstructive sleep apnea are often overweight or obese, and they frequently exhibit metabolic aberrations, collectively known as the metabolic syndrome, an established cardiovascular risk factor. We review recent data on the relationship between obstructive sleep apnea and metabolic syndrome or its components, including abdominal obesity, insulin resistance, hypertension, and dyslipidemia.
Recent Findings: There is accumulating evidence for an independent association between obstructive sleep apnea and metabolic syndrome or its components. Recent epidemiologic and clinical data suggest a causal role of severe obstructive sleep apnea in development of hypertension, but findings for insulin resistance and dyslipidemia are controversial. Visceral obesity remains a confounding issue in analyses. Animal models and translational studies indicate that obstructive sleep apnea may promote metabolic dysfunction through cycles of intermittent hypoxia; proposed underlying pathophysiologic mechanisms include oxidative stress, sympathetic activation, and inflammation.
Summary: There is suggestive evidence, but independent associations between obstructive sleep apnea and metabolic syndrome or its components are not fully established because of the confounding effect of obesity. Large randomized interventional trials are needed to identify any cause-effect relationship. Long-term follow-up studies would help to clarify the role of treatment of sleep apnea in reducing cardio-metabolic morbidity.
Obstructive sleep apnea (OSA) is a prevalent condition worldwide, affecting at least 1-5% of middle-aged individuals in various ethnic populations, and obesity has been demonstrated to be a major risk factor. There is growing concern regarding the potential adverse health outcomes attributable to OSA, in particular its impact on cardiovascular disease. It is now recognized that there is a marked association between OSA and the metabolic syndrome, a cluster of obesity-related cardio-metabolic factors that are known to increase cardiovascular risk. Mechanistically, there is accumulating evidence demonstrating that OSA results in many systemic effects that may contribute, independent of obesity, to the generation of various metabolic aberrations or cardiovascular pathology. This review presents recently reported data on the link between OSA and metabolic syndrome, with a focus on the evidence for an independent causal role of OSA in exacerbating cardio-metabolic risk factors.
Abstract and Introduction
Abstract
Purpose of Review: Patients with obstructive sleep apnea are often overweight or obese, and they frequently exhibit metabolic aberrations, collectively known as the metabolic syndrome, an established cardiovascular risk factor. We review recent data on the relationship between obstructive sleep apnea and metabolic syndrome or its components, including abdominal obesity, insulin resistance, hypertension, and dyslipidemia.
Recent Findings: There is accumulating evidence for an independent association between obstructive sleep apnea and metabolic syndrome or its components. Recent epidemiologic and clinical data suggest a causal role of severe obstructive sleep apnea in development of hypertension, but findings for insulin resistance and dyslipidemia are controversial. Visceral obesity remains a confounding issue in analyses. Animal models and translational studies indicate that obstructive sleep apnea may promote metabolic dysfunction through cycles of intermittent hypoxia; proposed underlying pathophysiologic mechanisms include oxidative stress, sympathetic activation, and inflammation.
Summary: There is suggestive evidence, but independent associations between obstructive sleep apnea and metabolic syndrome or its components are not fully established because of the confounding effect of obesity. Large randomized interventional trials are needed to identify any cause-effect relationship. Long-term follow-up studies would help to clarify the role of treatment of sleep apnea in reducing cardio-metabolic morbidity.
Introduction
Obstructive sleep apnea (OSA) is a prevalent condition worldwide, affecting at least 1-5% of middle-aged individuals in various ethnic populations, and obesity has been demonstrated to be a major risk factor. There is growing concern regarding the potential adverse health outcomes attributable to OSA, in particular its impact on cardiovascular disease. It is now recognized that there is a marked association between OSA and the metabolic syndrome, a cluster of obesity-related cardio-metabolic factors that are known to increase cardiovascular risk. Mechanistically, there is accumulating evidence demonstrating that OSA results in many systemic effects that may contribute, independent of obesity, to the generation of various metabolic aberrations or cardiovascular pathology. This review presents recently reported data on the link between OSA and metabolic syndrome, with a focus on the evidence for an independent causal role of OSA in exacerbating cardio-metabolic risk factors.