Table 3– The association of metabolic parameters with obstructive sleep apnoea severity evaluated as apnoea/hypopnoea index (AHI) and time for arterial oxygen saturation measured by pulse oximetry (Sp,O2) <90% total sleep time (TST) in the entire group
Dependent variableAdjusted β coefficient# (95% CI)p-valueAdjusted β coefficient (95% CI)p-value
Independent variable AHI
 WC cm0.073 (0.021–0.124)0.006
 SBP mmHg0.158 (0.071–0.244)<0.0010.149 (0.060–0.238)0.001
 DBP mmHg0.117 (0.037–0.196)0.0040.102 (0.021–0.183)0.014
 TG mmol·L−10.007 (0.003–0.011)0.0010.005 (0.001–0.010)0.009
 cHDL mmol·L−1-0.002 (-0.004–0.000)0.048-0.002 (-0.004–0.000)0.050
 FBG mmol·L−10.008 (-0.002–0.017)0.1190.007 (-0.003–0.017)0.162
 HbA1c %0.010 (0.005–0.016)<0.0010.010 (0.004–0.016)0.001
Independent variable time Sp,O2 <90% TST
 WC cm0.082 (0.012–0.152)0.023
 SBP mmHg0.117 (-0.003–0.238)0.0570.103 (-0.020–0.226)0.099
 DBP mmHg-0.008 (-0.119–0.102)0.882-0.032 (10.143–0.079)0.569
 TG mmol·L−10.006 (0.001–0.012)0.0290.005 (-0.001–0.010)0.092
 cHDL mmol·L−1-0.002 (-0.005–0.001)0.117-0.002 (-0.005–0.001)0.124
 FBG mmol·L−10.181 (-0.053–0.416)0.1290.168 (-0.071–0.407)0.168
 HbA1c %0.011 (0.004–0.019)0.0050.011 (0.003–0.019)0.008
  • Data were analysed using linear regression as the dependent variable of each metabolic parameter and AHI or time Sp,O2 <90% TST as the independent variable. WC: waist circumference; SBP: systolic blood pressure; DBP: diastolic blood pressure; TG: triglycerides; cHDL: high-density lipoprotein cholesterol; FBG: fasting blood glucose; HbA1c: glycosylated haemoglobin. #: data adjusted by age, sex, body mass index (BMI) and smoking; : data adjusted by age, sex, BMI, WC and smoking.