The J-Curve Association Between Blood Pressure and Mortality in Stroke Survivors

Figures & data

Figure 1 Study flow chart.

Table 1 Characteristics of the Study Population by Systolic Blood Pressure Categories

Variable	Total (n=1696)	SBP ≤100 mmHg (n=59)	SBP >100 to≤120mmHg (n=361)	SBP >120 to ≤140mmHg (n=608)	SBP >140 to ≤160mmHg (n=400)	SBP >160 mmHg (n=268)	P value
Age, years	68.3 (13.6)	61.7 (16.0)	62.3 (16.1)	68.4 (13.2)	71.9 (10.6)	72.2 (10.6)	<0.001
Male, %	843 (49.7%)	32 (54.2%)	177 (49.0%)	319 (52.5%)	198 (49.5%)	117 (43.7%)	0.176
Race/ethnicity, %							0.537
Non-Hispanic White	936 (55.2%)	31 (52.5%)	197 (54.6%)	355 (58.4%)	212 (53.0%)	141 (52.6%)
Non-Hispanic Black	440 (25.9%)	20 (33.9%)	92 (25.5%)	144 (23.7%)	108 (27.0%)	76 (28.4%)
Other race	320 (18.9%)	8 (13.6%)	72 (19.9%)	109 (17.9%)	80 (20.0%)	51 (19.0%)
Diabetes mellitus, %	492 (29.0%)	13 (22.0%)	96 (26.6%)	187 (30.8%)	112 (28.0%)	84 (31.3%)	0.376
Hypertension, %	1238 (73.0%)	36 (61.0%)	225 (62.3%)	428 (70.4%)	322 (80.5%)	227 (84.7%)	<0.001
Anti-hypertensive treatment, %	1127 (66.5%)	35 (59.3%)	207 (57.3%)	392 (64.5%)	287 (71.8%)	206 (76.9%)	<0.001
Congestive heart failure, %	312 (18.4%)	19 (32.2%)	53 (14.7%)	111 (18.3%)	72 (18.0%)	57 (21.3%)	0.015
Smoker, %	1015 (59.8%)	37 (62.7%)	226 (62.6%)	365 (60.0%)	232 (58.0%)	155 (57.8%)	0.668
Alcohol user, %	1201 (70.8%)	43 (72.9%)	272 (75.3%)	417 (68.6%)	289 (72.2%)	180 (67.2%)	0.121
Pulse, beats/min	75.4 (15.8)	72.8 (12.3)	72.5 (12.3)	72.7 (12.2)	71.1 (13.5)	72.5 (12.6)	0.162
Body mass index, kg/m^2	28.8 (6.54)	28.8 (7.05)	29.0 (6.64)	29.0 (6.83)	28.6 (6.45)	28.2 (5.68)	<0.001
Waist circumference, cm	102 (15.0)	103 (19.1)	102 (15.4)	103 (15.3)	101 (14.1)	100 (14.0)	<0.001
Stroke length, year	7.76 (8.25)	5.90 (6.74)	7.52 (7.69)	7.97 (8.87)	8.58 (8.66)	6.81 (7.00)	0.088

Notes: Data are presented as mean (SD), or n (%).

Abbreviation: SBP, systolic blood pressure.

Table 2 Characteristics of the Study Population by Diastolic Blood Pressure Categories

Variable	Total (n=1696)	DBP ≤60 mmHg (n=374)	DBP >60 to ≤70mmHg (n=439)	DBP >70 to ≤80mmHg (n=477)	DBP >80 to ≤90mmHg (n=277)	DBP >90 mmHg (n=129)	P value
Age, years	68.3 (13.6)	72.9 (10.9)	69.7 (13.7)	66.7 (14.6)	65.2 (13.5)	63.1 (12.8)	<0.001
Male, %	843 (49.7%)	182 (48.7%)	206 (46.9%)	234 (49.1%)	147 (53.1%)	74 (57.4%)	0.208
Race/ethnicity, %							<0.001
Non-Hispanic White	936 (55.2%)	229 (61.2%)	257 (58.5%)	267 (56.0%)	139 (50.2%)	44 (34.1%)
Non-Hispanic Black	440 (25.9%)	81 (21.7%)	93 (21.2%)	124 (26.0%)	84 (30.3%)	58 (45.0%)
Other race	320 (18.9%)	64 (17.1%)	89 (20.3%)	86 (18.0%)	54 (19.5%)	27 (20.9%)
Diabetes mellitus, %	492 (29.0%)	138 (36.9%)	136 (31.0%)	116 (24.3%)	74 (26.7%)	28 (21.7%)	<0.001
Hypertension, %	1238 (73.0%)	281 (75.1%)	305 (69.5%)	323 (67.7%)	217 (78.3%)	112 (86.8%)	<0.001
Anti-hypertensive treatment, %	1127 (66.5%)	271 (72.5%)	281 (64.0%)	288 (60.4%)	191 (69.0%)	96 (74.4%)	<0.001
Congestive heart failure, %	312 (18.4%)	73 (19.5%)	101 (23.0%)	75 (15.7%)	40 (14.4%)	23 (17.8%)	0.020
Smoker, %	1015 (59.8%)	222 (59.4%)	261 (59.5%)	281 (58.9%)	169 (61.0%)	82 (63.6%)	0.888
Alcohol user, %	1201 (70.8%)	252 (67.4%)	307 (69.9%)	338 (70.9%)	202 (72.9%)	102 (79.1%)	0.128
Pulse, beats/min	72.5 (12.6)	70.1 (12.3)	71.6 (11.8)	72.5 (12.2)	75.1 (14.4)	76.7 (12.1)	<0.001
Body mass index, kg/m^2	28.8 (6.54)	28.6 (6.32)	28.2 (6.44)	29.0 (6.60)	29.3 (6.86)	29.1 (6.50)	0.201
Waist circumference, cm	102 (15.0)	102 (14.6)	100 (14.8)	102 (15.2)	102 (15.9)	102 (14.8)	0.284
Stroke length, year	7.76 (8.25)	8.16 (8.52)	7.64 (8.49)	7.64 (8.00)	7.96 (8.37)	7.05 (7.34)	0.773

Notes: Data are presented as mean (SD), or n (%).

Abbreviation: DBP, diastolic blood pressure.

Table 3 Univariate COX Regression Analysis of Predictors for Mortality

	HR (95% CI)	P value
Age, years	1.07 (1.06, 1.08)	<0.001
Male	1.39 (1.22, 1.58)	<0.001
Race/ethnicity
Non-Hispanic White	1.00 (ref.)
Non-Hispanic Black	0.71 (0.60, 0.83)	<0.001
Other race	0.54 (0.44, 0.65)	<0.001
Diabetes mellitus	1.30 (1.12, 1.50)	<0.001
Hypertension	1.12 (0.97, 1.30)	0.132
Anti-hypertensive treatment	1.15(1.00,1.32)	0.043
Congestive heart failure	1.46 (1.25, 1.71)	<0.001
Alcohol user	0.99 (0.85, 1.15)	0.862
Smoker	1.15 (1.00, 1.31)	0.046
Pulse, beats/min	1.00 (1.00, 1.00)	0.092
Body mass index, kg/m^2	0.97 (0.96, 0.98)	<0.001
Waist circumference, cm	1.00 (0.99, 1.00)	0.039
Systolic blood pressure, mm Hg	1.01 (1.01, 1.01)	<0.001
Diastolic blood pressure, mm Hg	0.99 (0.92, 0.99)	<0.001
Stroke length, year	1.00(1.00,1.01)	0.397

Abbreviations: HR, hazard ratios; CI, confidence intervals.

Table 4 Adjusted Hazard Ratios (95% Confidence Intervals) for All-Cause Mortality

	All Cause Mortality		Cardiovascular and Cerebrovascular Mortality
	Model 1	Model 2	Model 1	Model 2
	HR (95% CI)	HR (95% CI)	HR (95% CI)	HR (95% CI)
SBP (mmHg)
SBP ≤100mmHg	1.70(1.12–2.59)*	1.71(1.11–2.64)*	0.86(0.35–2.11)	1.16(0.46–2.93)
SBP >100 to ≤120 mmHg	0.92(0.74–1.14)	0.96(0.77–1.19)	0.57(0.38–0.86)**	0.71 (0.47–1.08)
SBP >120 to ≤140 mmHg	1.00(ref.)	1.00(ref.)	1.00(ref.)	1.00(ref.)
SBP >140 to ≤160 mmHg	0.99(0.84–1.18)	1.00(0.84–1.19)	0.88(0.66–1.16)	0.86 (0.64–1.14)
SBP >160mmHg	1.16(0.97–1.39)	1.20(0.99–1.46)	1.14(0.86–1.53)	1.10 (0.80–1.50)
DBP (mmHg)
DBP ≤60mmHg	1.36(1.12–1.65)**	1.42(1.15–1.75)**	0.98 (0.69–1.39)	1.30 (0.89–1.89)
DBP >60 to ≤70mmHg	1.08(0.90–1.30)	1.05(0.87–1.27)	1.05 (0.78–1.43)	1.06 (0.77–1.44)
DBP >70 to ≤80mmHg	1.00(ref.)	1.00(ref.)	1.00(ref.)	1.00(ref.)
DBP >80 to ≤90mmHg	1.19(0.98–1.46)	1.17(0.95–1.43)	1.49 (1.09–2.04)	1.46 (1.05–2.02)*
DBP >90mmHg	1.14(0.88–1.48)	1.06(0.81–1.40)	1.22 (0.79–1.87)	1.08 (0.68–1.70)

Notes: Model 1 was adjusted for nonmodifiable risk factors (age and sex). Model 2 was adjusted for combination of nonmodifiable and modifiable risk factors (age, sex, race/ethnicity, diabetes mellitus, congestive heart failure, smoker, systolic pressure or diastolic pressure, body mass index, waist and anti-hypertensive treatment). **P<0.01, *P<0.05.

Abbreviations: SBP, systolic blood pressure; DBP, diastolic blood pressure; HR, hazard ratios; CI, confidence intervals.

Figure 2 Kaplan–Meier survival curves illustrating the rate of all-cause mortality according to SBP categories (A) and DBP categories (B).

Figure 3 Restricted cubic spline plots of the association between blood pressure and risk of death. (A) SBP: all cause mortality; (B) DBP: all cause mortality; (C) SBP: cardiovascular and cerebrovascular mortality; (D) DBP: cardiovascular and cerebrovascular mortality.

Table 5 Stratified Associations Between Systolic Blood Pressure and Mortality by Age, Sex and BMI

	SBP≤100 mmHg	SBP>100 to ≤120 mmHg	SBP>120 to ≤140 mmHg	SBP>140 to ≤160 mmHg	SBP>160 mmHg	P value
	HR(95% CI)	HR(95% CI)	HR	HR(95% CI)	HR(95% CI)	Trend	Interaction
Age
≤65, N=602	0.66(0.27–1.62)	0.73(0.47–1.15)	1.00(ref.)	1.56(1.02–2.40)	2.54(1.62–3.98)***	<0.001	<0.001
>65, N=1094	2.44(1.48–4.00)**	0.92(0.72–1.19)	1.00(ref.)	1.01 (0.84–1.22)	1.21(0.98–1.50)	0.303
Sex
Male, N=843	1.34(0.79–2.30)	1.05(0.79–1.40)	1.00(ref.)	0.99(0.79–1.40)	1.21(0.91–1.60)	0.658	0.441
Female, N=853	3.86(1.81–8.22)***	0.85(0.60–1.20)	1.00(ref.)	1.01(0.78–1.30)	1.17(0.89–1.54)	0.298
BMI
≥30, N=588	1.22(0.54–2.78)	1.13(0.75–1.70)	1.00(ref.)	1.01(0.71–1.42)	1.54(1.04–2.29)*	0.242	0.923
<30, N=1108	1.93(1.15–3.24)*	0.92(0.71–1.20)	1.00(ref.)	1.04(0.85–1.26)	1.14(0.91–1.43)	0.407

Notes: Analyses was adjusted for age, sex, race/ethnicity, diabetes mellitus, congestive heart failure, smoker, antihypertensive treatment, systolic pressure or diastolic pressure, body mass index and waist when they were not the strata variables. ***P< 0.001, **P<0.01, *P<0.05.

Abbreviations: SBP, systolic blood pressure; BMI, Body mass index; HR, hazard ratios; CI, confidence intervals.

Table 6 Stratified Associations Between Diastolic Blood Pressure and Mortality by Age, Sex and BMI

	DBP≤60 mmHg	DBP>60 to ≤70 mmHg	DBP>70 to ≤80mmHg	DBP>80 to ≤90 mmHg	DBP>90 mmHg	P value
	HR(95% CI)	HR(95% CI)	HR	HR(95% CI)	HR(95% CI)	Trend	Interaction
Age
≤65, N=602	1.72(0.96–3.09)	0.85(0.53–1.38)	1.00(ref.)	0.77(0.51–1.16)	0.56(0.34–0.94)*	0.006	0.165
>65, N=1094	1.61(1.29–2.01)***	1.20(0.98–1.48)	1.00(ref.)	1.14(0.90–1.45)	1.02(0.72–1.43)	<0.001
Sex
Male, N=843	1.43(1.07–1.89)*	1.06(0.82–1.37)	1.00(ref.)	1.27(0.96–1.68)	1.01(0.69–1.48)	0.225	0.884
Female, N=853	1.43(1.05–1.95)*	1.09(0.83–1.95)	1.00(ref.)	1.10(0.81–1.50)	1.13(0.75–1.71)	0.203
BMI
≥30, N=588	1.58(1.03–2.41)*	1.36(0.92–2.01)	1.00(ref.)	1.21(0.82–1.79)	1.04(0.59–1.80)	0.145	0.534
<30, N=1108	1.41(1.11–1.79)*	0.97(0.78–1.20)	1.00(ref.)	1.10(0.86–1.41)	1.00(0.72–1.40)	0.118

Notes: Analyses was adjusted for age, sex, race/ethnicity, diabetes mellitus, congestive heart failure, smoker, systolic pressure or diastolic pressure, body mass index and waist when they were not the strata variables. ***P< 0.001, **P<0.01, *P<0.05.

Abbreviations: DBP, diastolic blood pressure; BMI, Body mass index; HR, hazard ratios; CI, confidence intervals.

Figure 4 Restricted cubic spline plots of the association between blood pressure and all-cause mortality in different age groups. (A) SBP: age > 65 years; (B) DBP: age > 65 years; (C) SBP: age ≤ 65 years; (D) DBP: age ≤ 65 years.