Obstructive sleep apnea (OSA) was identified as an independent predictor of potentially dangerous lipid levels in a large cross-sectional analysis involving adults in Europe without a diagnosis of hyperlipidemia.
The analysis showed a strong association between higher total cholesterol, lower high density lipoprotein-cholesterol (HDL-C), higher low density lipoprotein cholesterol (LDL-C), elevated triglycerides, and several measures of OSA severity in the study of patients enrolled in the European Sleep Apnea Database.
The analysis is among the largest to suggest a link between OSA severity and lipid status, Ludger Grote, MD, PhD, of Gothenburg University in Sweden, and colleagues, wrote online in
"Our data clearly suggest that sleep apnea may have a negative impact on lipid levels, which may in part explain the association between sleep apnea and increased risk for cardiovascular disease," Grote noted in a press statement.
The cross-sectional analysis included 8,592 patients without physician-diagnosed hyperlipidemia who were not taking lipid-lowering drugs. All were enrolled in the European Sleep Apnea Database cohort, which includes data from 30 sleep centers across 20 countries in Europe and Israel.
The mean age of the patients included in the analysis was 50.1 (±12.7 years), 69% were male, body mass index (BMI) was 30.8±6.6, and mean apnea-hypopnea index (AHI) was 25.7±25.9 event/hour. The researchers controlled for both abdominal obesity and BMI.
The independent relationship between measures of OSA -- AHI, oxygen desaturation index (ODI), mean and lowest oxygen saturation -- and lipid profile -- total cholesterol (TC), HDL-C, LDL-C, and fasting triglycerides (TG) -- was determined using general linear model analysis.
Among the main study findings:
- There was a dose-response relationship between total cholesterol and oxygen desaturation index -- mean±SE (mg/dL): 180.33±2.46, 184.59±2.42, 185.44±2.42, and 185.73±2.44; P<0.001 across ODI quartiles I-IV
- Fasting triglyceride and LDL concentrations were better predicted by AHI than by ODI
- HDL-C was significantly reduced in the highest AHI quartile versus the lowest -- mean±SE (mg/dL): 48.8±1.49 versus 46.50±1.48; P=0.002
- Morbid obesity was associated with lower TC and higher HDL-C values, and geographical location was a factor in lipid status, with the highest total cholesterol concentrations recorded in northern Europe
"In this cross-sectional analysis of data collected from a prospective observational cohort, addressing the largest patient sample on this topic to date, obstructive sleep apnea was identified as an independent predictor of potentially harmful lipid levels," the researchers said.
They cited the multinational, multicenter design and large sample size of OSA patients as study strengths, with the cross-sectional design cited as the main study limitation.
"As a clinical implication of our findings, clinicians should be aware of the association between OSA and dyslipidemia," the team wrote. "Indeed comorbid dyslipidemia, a well recognized cardiovascular risk factor, is highly likely to affect the overall cardiovascular consequences and prognosis in OSA. Therefore, sleep physicians may systematically assess the coexistence of sleep apnea and traditional [cardiovascular] risk factors including smoking, hypertension, and dyslipidemia. Finally, the impact of OSA treatment on lipid status still needs to be further evaluated."
Disclosures
Funding for the research was provided by the European Respiratory Society, the European Union, the ResMed Foundation, and the Philips Respironics Foundation.
Primary Source
Respirology
Gunduz C, et al "Obstructive sleep apnea independently predicts lipid levels: Data from the European Sleep Apnea Database" Respirology 2018; DOI: 10.1111/resp.13372.