Central blood pressure is an independent predictor of future hypertension in young to middle-aged stage 1 hypertensives

Figures & data

Table I. Baseline characteristics in the whole group and in the participants divided according to whether they developed hypertension needing treatment (end-point) or remained untreated.

Variable	All subjects, n = 305	Untreated, n = 149	End-point, n = 156	p-value^a
Age, years	37.3 ± 10.3	34.8 ± 9.9	39.7 ± 10.1	< 0.001
Sex, % males	73.8	72.5	75.0	n.s
BMI, kg/m^2	24.7 ± 3.3	24.6 ± 3.4	24.7 ± 3.3	n.s.
Parental HT, n (%)	183 (61.4)	82 (56.9)	101 (65.6)	n.s.
Cigarette smokers, n (%)	61 (20.0)	25 (16.8)	36 (23.1)	n.s.
Alcohol drinkers, n (%)	123 (40.3)	51 (37.6)	67 (42.9)	n.s.
Coffee drinkers, n (%)	215 (71.9)	103 (71.5)	112 (72.2)	n.s.
Physically active, n (%)	144 (47.2)	76 (51.0)	68 (43.6)	0.04
Serum glucose, g/dl	91.0 ± 11.1	89.2 ± 10.1	92.8 ± 11.8	n.s.
Serum creatinine, mg/l	0.91 ± 0.17	0.92 ± 0.17	0.91 ± 0.17	n.s.
Uric acid, mg/dl	4.86 ± 1.3	4.71 ± 1.32	5.0 ± 1.30	n.s.
Albumin excretion rate, mg/24h	11.3 ± 24.5	9.38 ± 10.4	13.1 ± 32.4	n.s.^b
Total cholesterol, mg/dl	189.8 ± 38.9	184.2 ± 40.0	195.3 ± 37.2	n.s.
HDL-cholesterol, mg/dl	53.4 ± 14.1	55.1 ± 14.9	51.8 ± 13.2	n.s.
Triglycerides, mg/dl	111.2 ± 78.4	95.9 ± 59.1	126.1 ± 91.2	0.014^b
LVMI g/m^2	87.2 ± 15.4	87.0 ± 15.3	87.4 ± 15.6	n.s.

Data are mean values ± standard deviation; all p-values are adjusted for age and sex except age and sex. ^ap-value for untreated vs end-point subjects,; ^blog-transformed data. BMI, body mass index; HT, hypertension; HDL, high-density lipoprotein; LVMI, left ventricular mass index. n.s., not statistically significant (p > 0.05).

Table II. Baseline blood pressure values in the whole group and in the participants divided according to whether they developed hypertension needing treatment (end-point) or remained untreated.

Variable	All subjects, n = 305	Untreated, n = 149	End-point, n = 156	p-value^a
Brachial SBP, mmHg	144.3 ± 11.1	143.4 ± 12.0	145.1 ± 10.2	n.s.
Brachial DBP, mmHg	91.7 ± 6.3	90.2 ± 6.8	93.1 ± 5.5	0.036
Brachial HR, beats/min	74.1 ± 9.9	74.1 ± 9.9	74.2 ± 10.0	n.s.
Brachial mean BP, mmHg	109.2 ± 6.1	108.0 ± 7.0	110.4 ± 4.9	0.025
24-h SBP, mmHg	130.6 ± 10.4	128.8 ± 10.6	132.2 ± 10.0	< 0.001
24-h DBP, mmHg	79.5 ± 7.9	77.2 ± 8.0	81.7 ± 7.1	< 0.001
24-h MBP, mmHg	96.5 ± 7.1	94.4 ± 7.0	98.5 ± 6.6	< 0.001
24-h HR, beats/min	72.7 ± 8.1	71.8 ± 7.5	73.5 ± 8.5	0.051
Central SBP, mmHg	124.4 ± 13.5	121.5 ± 13.3	127.2 ± 13.2	0.007
Central DBP, mmHg	85.7 ± 7.6	83.8 ± 8.0	87.5 ± 6.8	0.001
Central MBP, mmHg	103.0 ± 9.1	100.8 ± 9.1	105.0 ± 8.6	0.002
Brachial PP, mmHg	52.6 ± 11.8	53.3 ± 11.8	52.0 ± 11.8	n.s.
24-h PP, mmHg	51.0 ± 11.0	51.6 ± 11.8	50.5 ± 10.3	n.s.
Central PP, mmHg	38.8 ± 11.0	37.6 ± 10.6	40.0 ± 11.3	n.s.

Data are mean values ± standard deviation. All p-values are adjusted for age and sex. ^ap-value for untreated vs end-point subjects. SBP, systolic blood pressure; DBP, diastolic blood pressure; MBP, mean blood pressure; HR, heart rate; PP, pulse pressure; n.s., not statistically significant (p > 0.05).

Table III. Correlation between brachial office, average 24-h and central systolic, diastolic and mean BP values.

	SBP		DBP		MBP
	Office BP	24-h BP	Office BP	24-h BP	Office BP	24-h BP
24-h BP	r = 0.37, p < 0.001		r = 0.42, p < 0.001		r = 0.29, p < 0.001
Central BP	r = 0.23, p = 0.003	r = 0.033, p = n.s.	r = 0.28, p < 0.001	r = 0.15, p = n.s.	r = 0.28, p < 0.001	r = 0.11, p = n.s.

SBP indicates systolic blood pressure; DBP, diastolic blood pressure; MBP, mean blood pressure; BP, blood pressure; n.s., not statistically significant (p > 0.05).

Table IV. Odds ratios and 95% confidence interval for development of hypertension needing antihypertensive treatment from multivariable adjusted logistic regressions.

Model		OR (95%CI)	p-value
Model 1	Brachial MBP	1.09 (1.04–1.15)	< 0.001
Model 2	24-h MBP	1.08 (1.03–1.12)	< 0.001
Model 3	Central MBP	1.06 (1.02–1.09)	< 0.001
Model 4	Central PP	1.02 (0.99–1.05)	n.s.
	Central MBP	1.06 (1.02–1.10)	0.002
Model 5	Brachial MBP	1.05 (0.99–1.11)	0.062
	24-h MBP	1.06 (1.01–1.11)	0.009
	Central MBP	1.05 (1.01–1.08)	0.006

Odds ratios represent risk of hypertension needing treatment according to brachial office, 24-h and central mean blood pressure values. OR, odds ratio; CI, confidence interval. All data are adjusted for age, sex, body mass index, parental hypertension, physical activity, smoking, coffee, alcohol consumption, follow-up time, 24-h heart rate. MBP, mean blood pressure; PP, pulse pressure; n.s., not statistically significant (p > 0.05).

Figure 1. Odds ratios of developing hypertension needing treatment in 305 stage 1 hypertensive subjects, divided into tertiles of brachial office, 24-h and central mean blood pressure. Office mean blood pressure: T1, 1st tertile (85.22–106.83 mmHg); T2, 2nd tertile (106.84–111.78 mmHg); T3, 3rd tertile (111.89–125.22 mmHg). Twenty-four-hour mean blood pressure: T1, 1st tertile (73.19–93.86 mmHg); T2, 2nd tertile (93.93–99.26 mmHg); T3, 3rd tertile (99.27–119.57 mmHg). Central mean blood pressure: T1, 1st tertile (77.00–99.20 mmHg); T2, 2nd tertile (99.30–105.56 mmHg); T3, 3rd tertile (105.57–133.00 mmHg). ‡p = 0.03 vs 1st tertile, §p = 0.004 vs 1st tertile †p < 0.01vs 1st tertile, *p < 0.001 vs 1st tertile.