The Associations of Trajectory of Sleep Duration and Inflammation with Hypertension: A Longitudinal Study in China

Figures & data

Figure 1 Sampling flowchart and participants enrollment.

Table 1 Sample Characteristics in 2004 and 2009

	2004	2009	p
	Mean (SD)/n (%)	Mean (SD)/n (%)
Personal characteristics
Energy intake (kcal/d)	2257.67 (649.36)	2158.63 (639.79)	<0.001
BMI (kg/m^2)	22.44 (2.57)	22.81 (2.84)	<0.001
Gender
Male	1366 (43.0)	–
Female	1812 (57.0)	–
Age (years)	47.98 (11.64)	52.95 (11.64)	<0.001
30–45	1329 (41.8)	851 (26.8)	<0.001
45–60	1316 (41.4)	1469 (46.2)
60–75	482 (15.2)	712 (22.4)
≥75	51 (1.6)	146 (4.6)
Residence
Urban	939 (29.5)	–
Rural	2239 (70.5)	–
Education
Low	2538 (79.9)	–
Medium	533 (16.8)	–
High	105 (3.3)	–
Income
Low	1048 (33.1)	1036 (33.4)	0.439
Medium	1098 (34.7)	1034 (33.3)
High	1017 (32.2)	1036 (33.4)
Physical activities
MET/day	1.59 (7.92)	1.59 (6.59)	0.970
Low	1673 (52.6)	1674 (52.7)	<0.001
Medium	874 (27.5)	798 (25.1)
High	631 (19.9)	706 (22.2)
Sedentary time (hours/day)
Low	1057 (33.3)	995 (31.3)	0.216
Medium	1016 (31.8)	1017 (32.0)
High	1105 (34.9)	1166 (36.7)
Smoke
No	2163 (68.2)	2206 (69.5)	0.275
Yes	1009 (31.8)	970 (30.5)
Drank alcohol
No	2164 (68.2)	2178 (68.6)	0.789
Yes	1007 (31.8)	999 (31.4)
Sleep duration, CRP, and hypertension
Sleep duration (hours/day)	8.13 (1.16)	7.91 (1.22)	<0.001
≤7 hours	773 (24.3)	973 (30.6)	<0.001
8–9 hours	1977 (62.2)	1866 (58.7)
≥10 hours	428 (13.5)	339 (10.7)
CRP (mg/L)	–	1.0 (0.0, 2.0)
Elevated CRP
No	–	2588 (81.4)
Yes	–	590 (18.6)
SBP	115.34 (11.25)	122.23 (16.37)
DBP	74.72 (7.97)	79.75 (10.79)
Hypertension
No	–	2334 (73.4)
Yes	–	844 (26.6)

Abbreviations: SD, standard deviation; BMI, body mass index; CRP, C-reactive protein; SBP, systolic blood pressure; DBP, diastolic blood pressure; MET, metabolic equivalent.

Table 2 The Distribution of Elevated CRP and Hypertension According to Sleep Duration Categories

	N	Elevated CRP (n, %)	p	Hypertension (n, %)	p
Participants at 2004
≤7 hours	773 (24.3)	144 (18.6)	0.834	235 (30.4)	0.001
8–9 hours	1977 (62.2)	371 (18.8)		479 (24.2)
≥10 hours	428 (13.5)	75 (17.5)		130 (30.4)
Participants at 2009
≤7 hours	973 (30.6)	202 (20.8)	0.024	286 (29.4)	<0.001
8–9 hours	1866 (58.7)	317 (17.0)		445 (23.8)
≥10 hours	339 (10.7)	71 (20.9)		113 (33.3)
Sleep change from 2004 to 2009
≤7 hours /day→≤7 hours	289 (9.1)	70 (24.2)	0.054	91 (31.5)	<0.001
≥10 hours→≥10 hours	72 (2.3)	16 (22.2)		29 (40.3)
Changed pattern	1620 (50.9)	288 (17.8)		472 (29.1)
8–9 hours→8–9 hours	1197 (37.7)	216 (18.0)		252 (21.1)

Table 3 The Association of Sleep Duration with Hypertension

	n (%)	Crude Model	Adjusted Model 1	Adjusted Model 2
		RR (95% CI)	RR (95% CI)	RR (95% CI)
2004
≤7 hours	773 (24.3)	1.239 (1.083, 1.418)	1.178 (1.032, 1.344)	1.192 (1.045, 1.359)
8–9 hours	1977 (62.2)	Reference	Reference	Reference
≥10 hours	428 (13.5)	1.279 (1.086, 1.506)	1.179 (1.005, 1.383)	1.169 (0.996, 1.371)
2009
≤7 hours	973 (30.6)	1.252 (1.102, 1.424)	1.197 (1.057, 1.356)	1.199 (1.059, 1.359)
8–9 hours	1866 (58.7)	Reference	Reference	Reference
≥10 hours	339 (10.7)	1.417 (1.192, 1.685)	1.220 (1.031, 1.443)	1.205 (1.019, 1.424)
Sleep change from 2004 to 2009
≤7 hours /day→≤7 hours	289 (9.1)	1.477 (1.201, 1.817)	1.383 (1.128, 1.696)	1.375 (1.121, 1.686)
≥10 hours→≥10 hours	72 (2.3)	1.949 (1.442, 2.634)	1.580 (1.185, 2.108)	1.557 (1.171, 2.069)
Changed pattern	1620 (50.9)	1.405 (1.228, 1.609)	1.332 (1.164, 1.524)	1.299 (1.135, 1.487)
8–9 hours→8–9 hours	1197 (37.7)	Reference	Reference	Reference

Notes: Adjusted Model 1 adjusted age, gender. Adjusted Model 2 additionally adjusted education, family income per capita, physical activities, sedentary time per day, smoke, drank alcohol, BMI.

Table 4 The Association of Sleep Duration with Elevated CRP

	Crude Model	Adjusted Model 1	Adjusted Model 2
	RR (95% CI)	RR (95% CI)	RR (95% CI)
2004
≤7 hours	0.998 (0.837, 1.190)	0.969 (0.812, 1.156)	0.959 (0.806, 1.141)
8–9 hours	Reference	Reference	Reference
≥10 hours	0.937 (0.746, 1.177)	0.908 (0.722, 1.142)	0.881 (0.702, 1.105)
2009
≤7 hours	1.223 (1.042, 1.436)	1.182 (1.007, 1.388)	1.169 (0.996, 1.372)
8–9 hours	Reference	Reference	Reference
≥10 hours	1.220 (0.956, 1.543)	1.130 (0.892, 1.431)	1.110 (0.878, 1.402)
Sleep change from 2004 to 2009
≤7 hours /day→≤7 hours	1.348 (1.060, 1.714)	1.283 (1.006, 1.635)	1.285 (1.008, 1.638)
≥10 hours→≥10 hours	1.255 (0.802, 1.965)	1.166 (0.742, 1.832)	1.201 (0.765, 1.886)
Changed pattern	1.001 (0.851, 1.177)	0.977 (0.830, 1.150)	0.965 (0.821, 1.134)
8–9 hours→8–9 hours	Reference	Reference	Reference

Notes: Adjusted Model 1 adjusted age, gender. Adjusted Model 2 additionally adjusted education, family income per capita, physical activities, sedentary time per day, smoke, drank alcohol, BMI.

Table 5 The Association of hs-CRP with Hypertension

	Crude Model	Adjusted Model 1	Adjusted Model 2
hs-CRP (mg/L)	RR (95% CI)	RR (95% CI)	RR (95% CI)
≤2	Reference	Reference	Reference
>2	1.380 (1.211, 1.572)	1.235 (1.088, 1.402)	1.204 (1.059, 1.368)

Notes: Adjusted Model 1 adjusted age, gender. Adjusted Model 2 additionally adjusted education, family income per capita, physical activities, sedentary time per day, smoke, drank alcohol, BMI.