Prognostic significance of dipping in older hypertensive patients

Figures & data

Table I. Comparison of groups according to diurnal sign, continuous variables.

	Dippers	Non-dippers	Reverse-dippers	p
Mean SBP (mmHg)	137 ± 15	136 ± 18	139 ± 17	0.602
Mean DBP (mmHg)	77 ± 8	78 ± 11	79 ± 10	0.582
Age (years)	79 ± 3,1	79 ± 2,7	79 ± 3,0	0.938
Mean surviving time (days)	1610 ± 446	1434 ± 607	1413 ± 483	0.088
Serum creatinin (μmol/l)	87.9 ± 16.8	91.8 ± 18.4	95,4 ± 25.4	0.317
Glycemia (mmol/l)	6.98 ± 2.10	7.40 ± 3.95	7,20 ± 3.87	0.471
BMI (kg/m^2)	24.67 ± 3.72	26.32 ± 4.42	26,28 ± 4.08	0.798

p, statistical significance by analysis of variance (ANOVA) test; SBP, systolic blood pressure; DBP, diastolic blood pressure; BMI, body mass index.

Table II. Comparison of groups according to diurnal sign, continuous variables.

	Normal diurnal sign (dippers)	Impaired diurnal sign (non- and reverse-dippers)	p
Mean SBP (mmHg)	137 ± 15	138 ± 17	0.197
Mean DBP (mmHg)	77 ± 8	79 ± 11	0.053
Age (years)	79 ± 3.2	79 ± 2.9	0.314
Mean surviving time (days)	1609 ± 446	1424 ± 546	0.003

p, statistical significance by t-test; SBP, systolic blood pressure; DBP, diastolic blood pressure.

Figure 1. Mortality according to diurnal sign. p ˂ 0.05 (Pearson chi-square).

Table III. Comparison of groups according to diurnal sign, discrete variables.

	Dippers (n = 40)	Non-dippers (n = 65)	Reverse-dippers (n = 65)	p
Male – % within the group	8 (20%)	14 (21.5%)	12 (18.5%)	0.908
Female – % within the group	32 (80%)	51 (78.5%)	53 (81.5%)
Number of deaths – % within the group	10 (25%)	23 (35.4%)	36 (55.4%)	0.005
Survived – % within the group	30 (75%)	42 (64.6%)	29 (44.6%)
BP well-controlled (≤ 130/80 mmHg) – % within the group	12 (30%)	25 (38.5%)	17 (26.2%)	0.309
BP in hypertension range – % within the group	28 (70%)	40 (61.5%)	48 (73.8%)

p, statistical significance by the Pearson chi-square test; BP, blood pressure.

Table IV. Comparison of groups according to diurnal sign, discrete variables.

	Normal diurnal sign (dippers) (n = 40)	Impaired diurnal sign (non- and reverse-dippers) (n = 130)	p
Male – % within the group	8 (20%)	26 (20%)	0.985
Female – % within the group	32 (80%)	104 (80%)
Death – % within the group	10 (25%)	59 (45.4%)	0.022
Survived – % within the group	30 (75%)	71 (54.6%)
BP good control – % within the group	12 (30%)	42 (32.3%)	0.784
BP in hypertension range – % within the group	28 (70%)	88 (67.7%)
Myocardial infarction history – % within the group	11 (27.5%)	43 (33.1%)	0.205
Heart failure – % within the group	18 (45%)	67 (51.5%)	0.363
Renal insufficiency – % within the group	7 (17.5%)	45 (34.6%)	0.04
Diabetes mellitus – % within the group	9 (22.5%)	53 (40.8%)	0.037
Atrial fibrillation or flutter – % within the group	12 (30.0%)	52 (40.0%)	0.287

p, statistical significance by the Pearson chi-square test.

Figure 2. Diurnal sign of groups divided according to mortality (p < 0.05).

Figure 3. Diurnal index of groups divided according to mortality (p < 0.05).

Table V. Comparison of groups according to mortality, continuous variables.

	Survived (n = 101)	Death (n = 69)	p
Age (years)	79.0 ± 2.98	79.9 ± 2.76	0.040
Mean SBP (mmHg)	135.7 ± 17.56	140.9 ± 14.90	0.042
Mean DBP (mmHg)	77.3 ± 10.2	79.6 ± 9.6	0.138
Mean day SBP (mmHg)	138.2 ± 18.2	141.5 ± 15.2	0.210
Mean day DBP (mmHg)	79.9 ± 10.9	80.6 ± 9.9	0.651
Mean night SBP (mmHg)	130.2 ± 20.0	140.2 ± 18.7	0.001
Mean night DBP (mmHg)	71.9 ± 11.6	77.5 ± 12.7	0.003
Diurnal index for SBP	− 5.44% ± 10.2%	− 0.72% ± 9.69%	0.003
Diurnal index for DBP	− 9.7110% ± 10.713%	− 3.6538% ± 12.472%	0.001
Surviving period (days)	1825 ± 0	891 ± 496	0.001
Serum creatinine (μmol/l)	85.32 ± 16.52	98.7 ± 19.84	0.001
Glycemia (mmol/l)	6.94 ± 2.07	7.36 ± 2.82	0.214
BMI (kg/m^2)	25.65 ± 3.88	25.67 ± 3.82	0.973

p, statistical significance according to t-test; SBP, systolic blood pressure; DBP, diastolic blood pressure; BMI, body mass index.

Table VI. Comparison of groups according to mortality, discrete variables.

	Survived (n = 101)	Death (n = 69)	p
Male (n = 34) – % in male group – % in survived/death group	18 (52.9%) (17.8%)	16 (47.1%) (23.2%)	0.437
Female (n = 136) – % in female group – % in survived/death group	83 (61.0%) (82.2%)	53 (39.0%) (76.8%)
Normal diurnal sign (dippers) (n = 40) – % in dippers group	30 (75,0%)	10 (25.0%)	0.022
Impaired diurnal sign (n = 130) – % in this group	71 (54.6%)	59 (45.4%)
Dippers (n = 40) – % in this group	30 (75.0%)	10 (25.0%)	0.005
Non-dippers (n = 65) – % in this group	42 (64.6%)	23 (35.4%)
Reverse-dippers (n = 65) – % in this group	29 (44.6%)	36 (55.4%)
Mean BP in hypertension range – % in this group	64 (55.2%)	52 (44.8%)	0.131
Smokers – % in this group	8 (7.76%)	6 (8.89%)	0.491
History of myocardial infarction – % in this group	22 (21.3%)	32 (47.7%)	0.029
Heart failure – % in this group	41 (39.8%)	44 (63.8%)	0.026
Chronic renal insufficiency – % in this group	28 (27.2%)	24 (35.8%)	0.084
Diabetes mellitus – % in this group	34 (33.0%)	28 (41.7)	0.416
Atrial fibrillation or flutter – % in this group	39 (37.8%)	25 (37.3%)	0.872

p, statistical significance according to the Pearson chi-square test.

Table VII. Cox regression analysis of risk factors for mortality (only significant values mentioned).

Parameter	B±SE	Exp (B) (95% CI)	p
Age (years)	0.106 ± 0.041	1.112 (1.025–1.205)	0.01
Mean SBP (mmHg)	0.018 ± 0.008	1.018 (1.001–1.094)	0.049
Mean DBP (mmHg)	0.028 ± 0.013	1.028 (1.002–1.055)	0.038
Diurnal sign (%)	0.031 ± 0.010	1.031 (1.012–1.051)	0.001
Myocardial infarction history	0.589 ± 0.250	1.802 (1.104–2.941)	0.019
Heart failure	0.578 ± 0.254	1.783 (1.084–2.935)	0.023
BMI (kg/m^2)	0.107 ± 0.037	1.113 (1.034–1.197)	0.004
s-Creatinine (μmol/l)	0.044 ± 0.008	1.048 (1.028–1.063)	< 0.001

CI, confidence interval; SBP, systolic blood pressure; DBP, diastolic blood pressure; BMI, body mass index.

Figure 4. Kaplan–Meier curves comparing survival rate in: (a) dippers, non-dippers and reverse-dippers; p = 0.014 (Mantel–Cox test); (b) non-dippers with reverse-dipper combined together; p = 0.027 (Mantel–Cox test); (c) according to serum creatinine groups (above and below 88 μmol/l), p < 0.001 (Mantel–Cox test); (d) according to systolic blood pressure (above and below 138 mmHg), p = 0.012 (Mantel–Cox test).