Age dependency of central and peripheral systolic blood pressures: Cross-sectional and longitudinal observations in European populations

Figures & data

Figure 1. Flow chart of study participants.

Table I. Baseline characteristics of participants by study phase and sex.

	All participants		Participants with follow-up
Characteristic	Women	Men	Women	Men
Number	731	689	208	190
Noorderkempen	374 (51.2)	352 (51.1)	102 (49.0)	95 (50.0)
Pilsen	73 (10.0)	73 (10.6)	43 (20.7)	27 (14.2)
Padova	119 (16.3)	120 (17.4)	–	–
Kraków	165 (22.6)	144 (20.1)	63 (30.3)	68 (35.8)
Anthropometrics
Age, year	41.4 ± 15.0	42.0 ± 15.7	40.1 ± 14.3	39.2 ± 15.7
Height, cm	163.4 ± 6.5	176.0 ± 7.1^‡	164.4 ± 6.9	176.8 ± 7.2^‡
Weight, kg	66.0 ± 12.8	80.3 ± 12.9^‡	65.8 ± 12.6	71.2 ± 12.1^‡
Body mass index, kg/m^2	24.9 ± 4.6	25.9 ± 4.1^‡	24.3 ± 4.3	25.3 ± 3.5*
Risk factors
Current smoking, n (%)	138 (18.9)	205 (29.7)^‡	43 (20.7)	63 (33.2)†
Alcohol intake, n (%)	300 (41.0)	494 (71.7)^‡	59 (28.4)	105 (55.3)^‡
Total cholesterol, mmol/l	5.05 ± 1.05	5.04 ± 1.05	5.13 ± 1.10	5.13 ± 1.15
Blood glucose, mmol/l	4.90 ± 0.83	5.17 ± 1.20^‡	4.84 ± 0.38	5.20 ± 0.47*
Hypertension, n (%)	104 (14.2)	174 (25.3)^‡	21 (10.1)	35 (18.4)*
Diabetes, n (%)	17 (2.33)	34 (4.93)^†	0	0
Previous CVD, n (%)	44 (6.02)	58 (8.42)	10 (4.81)	18 (9.49)
Peripheral haemodynamics
Systolic pressure, mmHg	120.4 ± 16.1	127.6 ± 14.9^‡	117.9 ± 15.6	124.6 ± 12.6^‡
Diastolic pressure, mmHg	75.1 ± 10.2	78.9 ± 10.6^‡	73.8 ± 9.7	76.8 ± 10.3^‡
Pulse pressure, mmHg	45.3 ± 11.3	48.7 ± 11.7^‡	44.1 ± 10.5	47.7 ± 10.6^‡
Heart rate, beats/min	66.8 ± 10.2	63.5 ± 10.9^‡	67.3 ± 10.1	64.8 ± 11.9*
Central haemodynamics
Systolic pressure, mmHg	110.2 ± 18.0	113.7 ± 15.4^‡	107.9 ± 18.1	109.8 ± 13.3
Diastolic pressure, mmHg	76.1 ± 10.4	79.8 ± 10.7^‡	74.8 ± 9.8	77.8 ± 10.4^†
Pulse pressure, mmHg	34.0 ± 12.3	33.9 ± 10.2	33.1 ± 12.6	32.0 ± 8.9

Values are mean ± SD or numbers of subjects (%). –, missing information; CVD, cardiovascular disease. Hypertension was a blood pressure of at least 140 mmHg systolic or 90 mmHg diastolic. Significance of the sex difference *p < 0.05, †p < 0.01, ^‡p < 0.001.

Figure 2. Association with age of peripheral and central systolic blood pressures (A,B), peripheral and central non-augmented systolic blood pressures (A,B), pressure amplification (C,D), and peripheral and central systolic augmentation (E,F) in women (A,C,E) and men (B,D,F). Peripheral systolic blood pressure was the average of three blood pressure readings at the brachial artery. Central systolic blood pressure was the maximum pressure of the central waveform. Systolic augmentation was obtained by subtracting the first systolic peak from systolic blood pressure. Pressure amplification is peripheral minus central systolic blood pressure. Plotted values are means for each age group. Numbers indicate the subjects contributing to the group means. All p-values for trend with age were statistically significant p<0.0001). Significance of the difference with zero: *p<0.05, ^†p<0.001.

Figure 3. Blood pressures at baseline and follow-up by sex and quarters of the age distribution. Plotted values are peripheral and central systolic blood pressures (A,B), pressure amplification (C,D), and peripheral and central systolic augmentation (E,F) in 208 women (A,C,E) and 190 men (B,D,F). All p-values for trend with age were statistically significant (p<0.01). Significance of the difference between baseline and follow-up: *p><0.05, ^†p><0.01, ^‡p< 0.001.

Table II. Cross-sectional association of blood pressure with age and longitudinal change in blood pressure with ageing in women and men.

	Cross-sectional associations with age (mmHg/year)
Variables by sex Timing	Baseline	Baseline	Follow-up	Longitudinal change (mmHg/year) Follow-up minus baseline
Women	All	Subgroup	Subgroup	Subgroup
Number	731	208	208	208
Peripheral systolic pressure	0.48 ± 0.03	0.48 ± 0.06	0.58 ± 0.07	0.91 ± 0.19
Central systolic pressure	0.73 ± 0.03	0.72 ± 0.06	0.79 ± 0.06	1.06 ± 0.22
Pressure amplification	−0.24 ± 0.01	−0.23 ± 0.02	−0.22 ± 0.02	−0.27 ± 0.07
Peripheral systolic augmentation	0.0500 ± 0.0059	0.0455 ± 0.0084	0.0955 ± 0.0154*	0.1010 ± 0.0267
Central systolic augmentation	0.395 ± 0.013	0.399 ± 0.023	0.472 ± 0.026*	0.551 ± 0.073
Men
Number	689	190	190	190
Peripheral systolic pressure	0.27 ± 0.03	0.14 ± 0.05	0.21 ± 0.06	1.24 ± 0.21
Central systolic pressure	0.51 ± 0.03	0.40 ± 0.05	0.49 ± 0.06	1.47 ± 0.20
Pressure amplification	−0.24 ± 0.01	−0.26 ± 0.02	−0.29 ± 0.02	−0.23 ± 0.09
Peripheral systolic augmentation	0.0187 ± 0.0039	0.0006 ± 0.0002	0.0167 ± 0.0046*	0.0220 ± 0.0104
Central systolic augmentation	0.301 ± 0.012	0.278 ± 0.019	0.330 ± 0.023*	0.513 ± 0.074

Regression coefficients (β ± SE) describe the cross-sectional associations of blood pressure with age. Subgroup refers to the subjects with repeat haemodynamic measurements at a median interval of 4.79 years. For the longitudinal assessment, values are average changes per year (follow-up minus baseline). Peripheral systolic blood pressure was the average of three blood pressure readings at the brachial artery. Central systolic blood pressure was the maximum pressure of the central waveform. Systolic augmentation was obtained by subtracting the first systolic peak from systolic blood pressure. Pressure amplification is peripheral minus central systolic blood pressure. All slopes on age were statistically significant (p< 0.01). In subjects with repeat examinations, an asterisk indicates a significant difference (p ≤ 0.039) between baseline and follow-up in the cross-sectionally assessed slopes on age. All changes from baseline to follow-up were significant (p< 0.05) except for peripheral systolic augmentation in men (p = 0.09).

Table III. Longitudinal changes in blood pressure by quarters of the distribution of peripheral systolic blood pressure at baseline in women and men.

	Quarters of the distribution of peripheral systolic blood pressure at baseline
Characteristic	Low	Medium-low	Medium-high	High	p-value
Women
Range of SBP at baseline, mmHg	<108	108–116	117–126	>127
Number of subjects	50	52	54	52
Peripheral SBP
Baseline, mmHg	101.3 ± 4.1	111.1 ± 2.2	118.8 ± 2.3	138.0 ± 12.9	< 0.0001
Follow-up, mmHg	109.7 ± 10.5	117.4 ± 10.1	121.5 ± 11.3	137.5 ± 17.4	< 0.0001
Absolute change, mmHg/year	1.73 ± 2.36^‡	1.33 ± 2.08^‡	0.82 ± 2.45*	−0.13 ± 3.51	0.0028
Central SBP
Baseline, mmHg	90.2 ± 17.4	100.8 ± 5.4	108.2 ± 7.2	128.2 ± 13.7	< 0.0001
Follow-up, mmHg	100.5 ± 10.1	108.1 ± 11.5	113.2 ± 12.6	129.3 ± 18.6	< 0.0001
Absolute change, mmHg/year	1.59 ± 3.92^†	1.50 ± 2.19^‡	1.08 ± 2.59^†	0.18 ± 3.50	0.076
Pressure amplification, mmHg/year	−0.34 ± 1.16*	−0.17 ± 1.04	−0.26 ± 0.76*	−0.31 ± 0.81^†	0.50
Men
Range of SBP at baseline, mmHg	<117	117–124	125–132	>133
Number of subjects	45	49	48	48
Peripheral SBP
Baseline, mmHg	110.6 ± 5.4	119.7 ± 1.5	127.2 ± 2.28	141.1 ± 9.6	< 0.0001
Follow-up, mmHg	122.8 ± 13.6	125.8 ± 9.2	130.7 ± 12.1	143.7 ± 15.2	< 0.0001
Absolute change, mmHg/year	2.46 ± 3.12^‡	1.29 ± 1.97^‡	0.70 ± 2.65	0.49 ± 3.40	0.0043
Central SBP
Baseline, mmHg	97.5 ± 6.5	105.5 ± 5.6	112.2 ± 7.5	124.4 ± 13.7	< 0.0001
Follow-up, mmHg	109.9 ± 12.8	112.8 ± 10.8	117.0 ± 13.0	128.6 ± 17.4	< 0.0001
Absolute change, mmHg/year	2.48 ± 2.74^‡	1.56 ± 1.85^‡	0.98 ± 2.56*	0.85 ± 3.54	0.017
Pressure amplification, mmHg/year	−0.02 ± 1.46	−0.26 ± 0.98	−0.28 ± 1.35	−0.36 ± 1.16*	0.041

Values are arithmetic means ± SD. SBP, systolic blood pressure. All changes from baseline to follow-up were significant (p < 0.05). Change in blood pressure was computed by subtracting baseline from follow-up measurements, p-values are for trend across quarters. Significance of the within-group changes: *p<0.05, ^†p><0.01, ^‡p< 0.001.

Table IV. Correlates of peripheral and central systolic blood pressures in women and men.

	Women (n = 731)			Men (n = 689)
	Peripheral	Central	P	Peripheral	Central	P
R^2	0.28	0.40		0.14	0.29
Intercept	69.4	57.1		95.9	72.5
Age (years)
β ± SE	0.421 ± 0.038^§	0.651 ± 0.039^§	<0.0001	0.236 ± 0.037^§	0.464 ± 0.035^§	<0.0001
Partial r^2	0.198	0.359		0.076	0.261
Body mass index, kg/m^2
β ± SE	0.830 ± 0.120^§	0.815 ± 0.122^§	0.546	0.486 ± 0.146^‡	0.499 ± 0.137^§	0.474
Partial r^2	0.062	0.043		0.014	0.017
Heart rate, beats/min
β ± SE	0.202 ± 0.05^†	0.094 ± 0.053*	0.172	0.287 ± 0.049^‡	0.136 ± 0.046^‡	0.109
Partial r^2	0.016	0.003		0.052	0.009
Smoking (0,1)
β ± SE	−2.811 ± 1.308^†	−2.311 ± 1.334*	0.182	ns	ns	−
Partial r^2	0.005	0.002

Values are partial regression coefficients (β ± SE) or partial coefficients of determination (r²). Significance of the partial regression coefficient: ns P>0.10; *p<0.10; ^†p<0.05, ^‡p<0.01, ^§p<0.001. The covariables considered in the stepwise regression procedure were: age, body mass index, heart rate and current smoking and drinking, p-values are for the comparison of the partial regression coefficients describing the associations with peripheral vs central blood pressure. -, not applicable.