The association between obstructive sleep apnea and metabolic syndrome: a systematic review and meta-analysis

Abstract

BackgroundObstructive sleep apnea (OSA) is characterized by repeated episodes of obstruction of the upper airway. Numerous studies have indicated a relationship between OSA and metabolic syndrome (MS), but the results remain debatable. We aimed to perform a systematic review and meta-analysis to evaluate the association between OSA and MS.MethodsWe searched electronic databases (PubMed, EMBASE, and ISO Web of Knowledge) up to September 2014 with English-language restriction. Cross-sectional, case–control, and cohort studies in which the presence of OSA was assessed by objective measurements, the exposure of interest was OSA, and the outcome of interest was the presence (or incidence) of MS were included. The adjusted odds ratios (ORs) (or relative risk) and 95 % confidence intervals (CIs) were extracted and pooled. Sensitivity analyses were conducted, and heterogeneity and publication bias were assessed.ResultsOverall, 15 cross-sectional (2456 patients with OSA and 1705 subjects without OSA), five case–control (1156 OSA patients and 404 controls), and no cohort studies were included. The pooled ORs of MS in individuals with OSA for cross-sectional and case–control studies were 2.87 (95 % CI: 2.41–3.42) and 2.56 (95 % CI: 1.98–3.31), respectively. There was clinically unimportant (I2 = 20 %) and moderate (I2 = 35 %) between-study heterogeneity of the analysis. The pooled crude ORs of MS in individuals with mild and moderate-to-severe OSA was 2.39 (95 % CI: 1.65–3.46) and 3.45 (95 % CI: 2.33–5.12), respectively, and there was substantial heterogeneity in the meta-analyses (I2 = 53 % and I2 = 63 %, respectively). However, no evidence of publication bias was detected.ConclusionsOSA is shown to be associated with MS, although causality between these two factors has not been demonstrated yet. Future cohort and randomized controlled studies are needed.Electronic supplementary materialThe online version of this article (doi:10.1186/s12890-015-0102-3) contains supplementary material, which is available to authorized users.

Morning Diastolic Blood Pressure May Be Independently Associated With Severity of Obstructive Sleep Apnea in Non-Hypertensive Patients: A Cross-Sectional Study

“…5 Both OSA and HT are comorbidities of obesity and are related to metabolic syndrome. 6,7 In some patients, HT may be solely secondary to OSA. It is presumed that the arterial blood pressure (BP) is elevated by intermittent hypoxemia during the night, which activates the sympathetic system via peripheral and central chemoreceptors.…”

Sleep and Polysomnographic Alterations in Patients with Syndrome Z

“…In a recent meta-analysis, OSAHS was showed to be associated with MS, although causality between these alterations has not been demonstrated [21]. Why patients with syndrome Z can present more alterations than patients with OSHAS only?…”

A Lifestyle Modification Program Associated With Weight Loss Reduces the Severity of OSA

“…Studies have shown that OSA is associated with an increased risk of hypertension, congestive heart failure, type II diabetes, stroke, and premature death. [1][2][3][4] This is an area of growing public health concern as the most current data show that the prevalence of moderate to severe OSA ranges from 10% to 17% in men and from 3% to 9% in women, a notable increase of >25% over the last 2 decades. 5 Obesity is a known causal factor for OSA, and studies estimate that over 50% of the moderate to severe OSA cases occur in patients with an elevated body mass index (BMI).…”

“…2,3 The outcome of patients with small subsegmental pulmonary emboli in whom anticoagulation is withheld has not been established clearly by randomized trials or retrospective analyses. 4 Many technical factors can influence the quality of the CTA, including respiratory motion, the timing of contrast injection, and image artifact. The interpretation of these suboptimal studies may result in false-positive or false-negative results, with significant variability in the interobserver agreement among different radiologists.…”