Table 3

Determinants of HRV, n = 397

Variable	SDNN (ms)^*		RMSSD (ms)^*		PNN50 (%)^*		LF:HF Ratio^†
Variable	Estimate	P value	Estimate	P value	Estimate	P value	Estimate	P value
Intercept	5.56	<0.0001	5.82	<0.0001	546.2	<0.0001	−1.90	0.0001
Time-weighted HbA_1c	−0.08	<0.0001	−0.12	<0.0001	−19.4	<0.0001	0.06	0.0166
Age (years)	−0.03	0.0131	−0.04	0.0100	−7.1	0.0024	0.03	0.0920
Smoking in the past month	0.02	0.7675	−0.06	0.5028	−6.0	0.6671	0.29	0.0162
Male	0.07	0.1878	0.02	0.8384	−2.3	0.8450	0.21	0.0420
Race-ethnicity
Non-Hispanic black	0.14	0.0578	0.37	0.0005	55.1	0.0007	−0.45	0.0012
Hispanic	−0.02	0.7243	0.05	0.5839	10.2	0.5016	−0.11	0.3907
Other	0.12	0.3013	0.19	0.2491	28.4	0.2661	−0.04	0.8568
BMI (kg/m²)	−0.01	0.0006	−0.01	0.0026	−1.95	0.0048	0.02	0.0013
Model R²	0.14	<0.0001	0.16	<0.0001	0.17	<0.0001	0.11	<0.0001

The full model includes a measure of glycemic control (time-weighted HbA_1c), sex (referent group = Female), race-ethnicity (referent group = non-Hispanic white), smoking in the past month (referent group = No), and age and BMI at the time of the HRV assessment. Parameter estimates for each covariate included in the model and the full model R² are given.
↵* Lower = worse.
↵† Higher = worse.