Recent studies indicate that ambient temperature may modulate obstructive sleep apnoea (OSA) severity. However, study results are contradictory warranting more investigation in this field. We analysed 19,293 patients of the European Sleep Apnoea Database (ESADA) cohort with restriction to the three predominant climate zones according to the Köppen-Geiger climate classification: Cfb (warm temperature, fully humid, warm summer), Csa (warm temperature, summer dry, hot summer), and Dfb (snow, fully humid, warm summer). Average outside temperature values were obtained and several hierarchical regression analyses were performed to investigate the impact of temperature on the apnea-hypopnea index (AHI), oxygen desaturation index (ODI), time of oxygen saturation <90% (T90) and minimum oxygen saturation (MinSpO2 ) after controlling for confounders including age, body mass index, gender, and air conditioning (A/C) use. AHI and ODI increased with higher temperatures with a standardised coefficient beta (β) of 0.28 for AHI and 0.25 for ODI, while MinSpO2 decreased with a β of -0.13 (all results p < .001). When adjusting for climate zones, the temperature effect was only significant in Cfb (AHI: β = 0.11) and Dfb (AHI: β = 0.08) (Model 1: p < .001). The presence of A/C (3.9% and 69.3% in Cfab and Csa, respectively) demonstrated only a minor increase in the prediction of the variation (Cfb: AHI, R2 +0.003; and Csa: AHI, R2 +0.007; both p < .001). Our present study indicates a limited but consistent influence of environmental temperature on OSA severity and this effect is modulated by climate zones.
BACKGROUND AND OBJECTIVE: Obstructive sleep apnoea (OSA) and hyperlipidaemia are independent risk factors for cardiovascular disease. This study investigates the association between OSA and prevalence of hyperlipidaemia in patients of the European Sleep Apnea Database (ESADA) cohort. METHODS: The cross-sectional analysis included 11 892 patients (age 51.9 ± 12.5 years, 70% male, body mass index (BMI) 31.3 ± 6.6 kg/m2 , mean oxygen desaturation index (ODI) 23.7 ± 25.5 events/h) investigated for OSA. The independent odds ratio (OR) for hyperlipidaemia in relation to measures of OSA (ODI, apnoea-hypopnoea index, mean and lowest oxygen saturation) was determined by means of general linear model analysis with adjustment for important confounders such as age, BMI, comorbidities and study site. RESULTS: Hyperlipidaemia prevalence increased from 15.1% in subjects without OSA to 26.1% in those with severe OSA, P < 0.001. Corresponding numbers in patients with diabetes were 8.5% and 41.5%, P < 0.001. Compared with ODI quartile I, patients in ODI quartiles II-IV had an adjusted OR (95% CI) of 1.33 (1.15-1.55), 1.37 (1.17-1.61) and 1.33 (1.12-1.58) (P < 0.001), respectively, for hyperlipidaemia. Obesity was defined as a significant risk factor for hyperlipidaemia. Subgroups of OSA patients with cardio-metabolic comorbidities demonstrated higher prevalence of HL. In addition, differences in hyperlipidaemia prevalence were reported in European geographical regions with the highest prevalence in Central Europe. CONCLUSION: Obstructive sleep apnoea, in particular intermittent hypoxia, was independently associated with the prevalence of hyperlipidaemia diagnosis.
- MeSH
- Hyperlipidemias epidemiology MeSH
- Cardiovascular Diseases epidemiology MeSH
- Middle Aged MeSH
- Humans MeSH
- Obesity epidemiology MeSH
- Sleep Apnea, Obstructive epidemiology MeSH
- Polysomnography MeSH
- Prevalence MeSH
- Cross-Sectional Studies MeSH
- Risk Factors MeSH
- Check Tag
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Europe MeSH
