Table 3.

Association between Heart Rate Variability (HRV) Parameters from the Deep Breathing Test and mean Carotid Artery Intimal-Media Thickness (CIMT).

HRV parameters	CIMT (mm)
	Unadjusted model			Adjusted model*
	Odds Ratio	95% CI	P-value	Odds Ratio	95% CI	P-value
SDNN (ms)	−0.003	−0.004 to −0.002	<0.001	−0.002	−0.003 to −0.001	0.005
CV	−0.025	−0.035 to −0.016	<0.001	−0.016	−0.026 to −0.006	0.002
RMSSD (ms)	−0.003	−0.005 to −0.001	<0.001	−0.002	−0.003 to −0.000	0.03
PNN50	−0.004	−0.006 to −0.001	0.002	−0.002	−0.004 to −0.000	0.1
SD1	−0.004	−0.006 to −0.002	<0.001	−0.002	−0.005 to −0.000	0.03
SD2	−0.002	−0.003 to −0.001	<0.001	−0.001	−0.002 to 0.000	0.004

^*All models adjusted for atherosclerotic cardiovascular disease (ASCVD) risk score (to include age, gender, race, HDL and total cholesterol, diabetes, systolic blood pressure, hypertension treatment and smoking), body mass index (BMI), waist-hip-ratio (WHR), left ventricular ejection fraction (LVEF); SDNN, standard deviation of all normal RR intervals; CV, coefficient of variation of RR intervals; RMSSD, root-mean square of differences between adjacent normal RR intervals; PNN50, the proportion of NN50 divided by total number of RRs, where NN50 represents the number of pairs of successive RRs that differ by more than 50 ms.; SD1, dispersion of points perpendicular to the axis of line-of-identity; SD2, dispersion of points along the line of identity; SD1/SD2, ratio of SD1 to SD2.