Table 4.
Regression Analyses – correlates of cardiovascular disease risk measures
| R2 change | R2 change p-value | Variable Std β-coeff. | β-coeff. p-value | Overall model adjusted R2 | Overall model p-value | |
|---|---|---|---|---|---|---|
| Maximal carotid IMT | ||||||
| BMI entered | 0.191 | 0.026 | 0.593 | 0.004 | 0.157 | 0.026 |
| After BMI, LN_AHI (forced entry) adds: | 0.056 | 0.203 | −0.171 | 0.365 | 0.182 | 0.038 |
| After BMI&LN_AHI, HDL (step-wise) adds | 0.166 | 0.021 | 0.424 | 0.021 | 0.333 | 0.007 |
| Carotid artery diameter | ||||||
| BMI entered | 0.02 | 0.463 | −0.069 | 0.666 | −0.016 | 0.463 |
| After BMI, LN_AHI (forced entry): NO VARIABLES ENTERED MODEL * | 0.021 | 0.457 | 0.023 | 0.8898 | −0.033 | 0.579 |
| After BMI&LN_AHI, mean ETCO2 (stepwise) adds: | 0.364 | 0.001 | −0.562 | 0.001 | 0.334 | 0.004 |
| After BMI, LN_AHI& mean ETCO2, male sex adds: | 0.127 | 0.018 | 0.385 | 0.018 | 0.454 | 0.001 |
| CFPWV | ||||||
| BMI entered | 0.29 | 0.003 | 0.64 | 0.001 | 0.26 | 0.03 |
| After BMI, LN_AHI (entered) adds: | 0.003 | 0.76 | −0.14 | 0.41 | 0.24 | 0.012 |
| After BMI&LN_AHI, Age (step-wise) adds: | 0.17 | 0.01 | 0.42 | 0.01 | 0.39 | 0.001 |
| Augmentation index AP/PP (AIx) | ||||||
| BMI entered | 0.125 | 0.056 | −0.117 | 0.602 | 0.093 | 0.056 |
| After BMI, LN_AHI (entered) adds: | 0.005 | 0.698 | −0.038 | 0.844 | 0.065 | 0.153 |
| After BMI&LN_AHI, LN_HOMA-IR (stepwise) adds: | 0.136 | 0.037 | −0.442 | 0.037 | 0.181 | 0.043 |
Additional variables incorporated into serial secondary regression models which were not significant predictors:
• CIMTmax: After BMI, LN_AHI and HDL, serial secondary models included the following non-significantly-contributing variables in turn: SBP Z-score, age, TGs, waist circumference, LN_ HOMA-IR, sagittal abdominal diameter.
• CCA diameter: After BMI, LN_AHI, mean ETCO2: age, TGs, SBP-z-score, neck circumference, waist circumference, LN_HOMA-IR.
• CFPWV: After BMI, LN_AHI, and age: HR (awake), lowest asleep HR, SBP Z-score, MAP, sex, waist circumference, LN_HOMA-IR.
• AIx: After BMI, LN_AHI, and LN_ HOMA-IR: age, HR, MAP, SBP Z-score, pulse pressure, waist circumference.
No variables entered – neither BMI nor LN_AHI were significant predictors of CCA diameter
Legend: CFPWV= carotid-femoral pulse-wave velocity; CCA=common carotid artery cIMTmax = maximal carotid intima-media thickness; AIx=augmentation index (AP/PP); BMI=body mass index; AHI=apnea hypopnea index; LN=natural log; ETCO2=end-tidal CO2; HDL=high-density lipoprotein; SBP=systolic blood pressure; HOMA-IR=homeostasis model assessment of insulin resistance; HR=heart rate; MAP=mean arterial pressure; TGs=triglycerides