ABSTRACT
RATIONALE: Chronic intermittent hypoxia occurring in obstructive sleep apnea (OSA) is independently associated with nonalcoholic fatty liver disease (NAFLD). Chronic obstructive pulmonary disease (COPD) has also been suggested to be linked with liver disease. OBJECTIVE: In this individual participant data meta-analysis, we investigated the association between liver damage and OSA and COPD severity. METHODS AND MEASUREMENTS: Patients suspected of OSA underwent polysomnography (PSG) or home sleep apnea testing (HSAT). Non-invasive tests were used to evaluate liver steatosis (Hepatic Steatosis Index) and fibrosis (Fibrotest or FibroMeter). An individual participant data meta-analysis approach was used to determine if the severity of OSA/COPD affects the type and severity of liver disease. Results were confirmed by multivariate and causal mediation analysis. Sub-group analyses were performed to investigate specific populations. MAIN RESULTS: Among 2120 patients, 1584 had steatosis (75%). In multivariable analysis, risk factors for steatosis were an apnea-hypopnea index (AHI) > 5/h, body mass index (BMI) > 26 kg/m2, age, type 2 diabetes (all p-values <0.01) and male gender (p = 0.02). Concerning fibrosis, among 2218 patients 397 had fibrosis (18%). Risk factors associated with fibrosis were BMI>26 kg/m2, age, male gender, and type 2 diabetes (all p-values <0.01). AHI severity was not associated with fibrosis. A combination of AHI >30/h and COPD stage 1 was associated with an increased risk of steatosis. CONCLUSION: This meta-analysis confirms the strong association between steatosis and the severity of OSA. The relation between OSA and fibrosis is mainly due to BMI as shown by causal mediation analysis.
Subject(s)
Diabetes Mellitus, Type 2 , Non-alcoholic Fatty Liver Disease , Pulmonary Disease, Chronic Obstructive , Sleep Apnea, Obstructive , Humans , Male , Non-alcoholic Fatty Liver Disease/complications , Non-alcoholic Fatty Liver Disease/epidemiology , Polysomnography , Pulmonary Disease, Chronic Obstructive/complications , Pulmonary Disease, Chronic Obstructive/epidemiology , Sleep Apnea, Obstructive/complications , Sleep Apnea, Obstructive/epidemiologyABSTRACT
Obstructive sleep apnea (OSA) may contribute to the development of nonalcoholic fatty liver disease. We performed a multisite cross-sectional study to evaluate the association between the severity of OSA and blood markers of liver steatosis (using the hepatic steatosis index), cytolysis (based on alanine aminotransferase activity), and significant liver fibrosis (based on the FibroMeter [Echosens] nonalcoholic fatty liver disease score) in 1285 patients with suspected OSA in France. After adjusting for confounders including central obesity, the risk of liver steatosis increased with the severity of OSA (P for trend < .0001) and sleep-related hypoxemia (P for trend < .0003 for mean oxygen saturation). Decreasing mean oxygen saturation during sleep also was associated independently with a higher risk of liver cytolysis (P for trend < .0048). Severe OSA conferred an approximate 2.5-fold increase in risk for significant liver fibrosis compared with patients without OSA, but the association between OSA severity and liver fibrosis was not maintained after adjusting for confounders.
Subject(s)
Biomarkers/blood , Fatty Liver/etiology , Fatty Liver/pathology , Sleep Apnea, Obstructive/complications , Sleep Apnea, Obstructive/pathology , Adult , Aged , Alanine Transaminase/blood , Cross-Sectional Studies , Female , France , Humans , Liver Cirrhosis/etiology , Liver Cirrhosis/pathology , Male , Middle Aged , Risk AssessmentABSTRACT
Obstructive sleep apnea (OSA) and short sleep duration are individually associated with an increased risk for hypertension (HTN). The aim of this multicenter cross-sectional study was to test the hypothesis of a cumulative association of OSA severity and short sleep duration with the risk for prevalent HTN. Among 1,499 patients undergoing polysomnography for suspected OSA, 410 (27.3%) previously diagnosed as hypertensive and taking antihypertensive medication were considered as having HTN. Patients with total sleep time (TST) <6 h were considered to be short sleepers. Logistic regression procedures were performed to determine the independent association of HTN with OSA and sleep duration. Considering normal sleepers (TST ≥6 h) without OSA as the reference group, the odds ratio (OR) (95% confidence intervals) for having HTN was 2.51 (1.35-4.68) in normal sleepers with OSA and 4.37 (2.18-8.78) in short sleepers with OSA after adjustment for age, gender, obesity, diabetes, depression, current smoking, use of thyroid hormones, daytime sleepiness, poor sleep complaint, time in bed, sleep architecture and fragmentation, and study site. The risk for HTN appeared to present a cumulative association with OSA severity and short sleep duration (p<0.0001 for linear trend). The higher risk for HTN was observed in short sleepers with severe OSA (AHI ≥30) (OR, 4.29 [2.03-9.07]). In patients investigated for suspected OSA, sleep-disordered breathing severity and short sleep duration have a cumulative association with the risk for prevalent HTN. Further studies are required to determine whether interventions to optimize sleep may contribute to lower BP in patients with OSA.
