Table 1 Descriptive statistics stratified by sex.

From: Heritability and genetic and environmental correlations of heart rate variability and baroreceptor reflex sensitivity with ambulatory and beat-to-beat blood pressure

Characteristics

Men

Women

p-value

N

Statistica

N

Statistica

Anthropometric measurement

Age (years)

554

26.5 (20.0–42.0)

677

30.0 (22.0–45.0)

NS

Height (cm)

554

166.0 (161–170.1)

677

152.0 (149.0–155.5)

<0.01

Weight (kg)

554

67.0 (58.0–77.0)

677

56.0 (49.5–67.0)

<0.01

Body mass index (kg/m2)

554

24.6 (20.9–28.2)

677

24.7 (21.2–28.6)

NS

Ambulatory and office beat-to-beat BP

Daytime SBP (mmHg)

534

127.0 (121.0–135.0)

644

119.0 (111.0–128.0)

<0.01

Daytime DBP (mmHg)

534

82.0 (76.8–89.0)

644

80.0 (74.0–88.0)

<0.01

Sleep SBP (mmHg)

513

109.0 (102.0–118.5)

625

104.0 (95.0–114.5)

<0.01

Sleep DBP (mmHg)

513

68.0 (61.0–75.0)

625

66.0 (59.0–73.0)

<0.05

Total 24-hour SBP (mmHg)

523

124.0 (117.0–131.0)

632

116.0 (108.0–125.0)

<0.01

Total 24-hour DBP (mmHg)

523

79.0 (74.0–86.0)

632

77.0 (71.3–84.0)

<0.01

Office beat-to-beat SBP (mmHg)

507

116.4 (108.2–124.9)

616

105.1 (98.2–113.0)

<0.01

Office beat-to-beat DBP (mmHg)

507

74.0 (68.0–82.1)

616

66.6 (60.4–73.0)

<0.01

Heart rate (variability) and Baroreceptor reflex sensitivity

SDNN (ms)

523

64.4 (47.8–81.4)

624

51.0 (37.6–65.5)

<0.01

RMSSD (ms)

523

39.5 (28.4–56.1)

624

33.9 (22.8–49.6)

<0.01

lnHF (ms2)

498

10.8 (1.4)

610

10.4 (1.5)

<0.01

lnLF (ms2)

500

4.2 (1.2)

610

3.4 (1.3)

<0.01

lnVLF (ms2)

500

3.4 (1.1)

610

2.8 (1.2)

<0.01

lnTP (ms2)

500

5.1 (1.1)

610

4.5 (1.2)

<0.01

HR (beats/min)

526

66.9 (61.5–74.1)

629

72.6 (66.0–79.2)

<0.01

lnBRS (ms/mmHg)

471

2.7 (0.6)

555

2.6 (0.7)

<0.01

  1. SDNN: standard deviation of normal-to-normal intervals; BP: blood pressure; SBP: systolic blood pressure; DBP: diastolic blood pressure; RMSSD: root mean square of successive differences; HF: high frequency; LF: low frequency; VLF: very low frequency; TP: total power; HR: heart rate; BRS: baroreceptor sensitivity; SDNN, RMSSD and HR were transformed by natural logarithm prior to testing for sex differences. NS: not significant.
  2. The daytime and sleep periods were determined for each subject according to their actual waking and sleeping time as recorded in their diaries.
  3. a:Data expressed as mean (sd) for normally distributed variable or median [IQR] in case of skewed distribution.