Does self-perceived income priority matter? The association between income inequality and allostatic load in China

Figures & data

Table 1. Prevalence of high-risk individual biomarkers for allostatic load in 2009 China Health and Nutrition Survey (N = 7673).

Biomarkers	% High risk	High-risk range
Cardiovascular System
Systolic blood pressure	13.5	> =140 mmHg
Diastolic blood pressure	21.78	> =90 mmHg
Metabolic system
BMI	29.15	> = 25
Waist-to-hip ratio	47.95	Male > 0.9; female > 0.85;
High-density lipoprotein (HDL)	25.24	Male < 40 mg/dl; female < 50 mg/dl
Low-density lipoprotein (LDL)	29.66	> 130 mg/dl
Total cholesterol	33.78	> = 200 mg/dl
Triglycerides	28.42	> = 160 mg/dl
HbA1c	3.65	> = 7%
Fasting glucose	6.14	> = 126 mg/dl
Inflammation System
High-sensitivity C-reactive protein (CRP)	23.19	> = 0.3 mg/dl
Albumin	0.34	<3.8 g/dl
Urinary system
Creatinine clearance	12.49	ages 18–19 < 0.5 or > 1.0 mg/dl; ages 20 + male < 0.66 or > 1.25; ages 20 + female < 0.52 or > 1.04 mg/dl
Uric acid	9.12	ages 18+ male < 3.5 or > 8.5 mg/dl; ages 18–34 female < 2.5 or > 6.2 mg/dl; ages 35–44 female < 2.5 or > 7.0 mg/dl; ages 45 + female < 2.5 or > 7.5 mg/dl;
Mean allostatic score (SD)	2.84 (2.20)

Table 2. Descriptive analyses of sample characteristics (age > = 18 years, 2009 and 2006).

	2009		2006
	Mean or %	SD	Mean or %	SD
Age	49.64	14.67	49.56	13.72
Gender
Male	46.77	–	45.73	–
Female	53.23	–	54.27	–
Marital status
Married	85.53	–	89.02	–
Divorced/separated/widowed	8.26	–	7.16	–
Single	6.21	–	3.82	–
Residence
Urban	32.27	–	31.41	–
Rural	67.73	–	68.59	–
Education
No schooling	21.87	–	25.5	–
Elementary	19.79	–	19.83	–
Middle school	34.1	–	31.25	–
High school or equivalent	19.1	–	19.63	–
College or above	5.14	–	3.79	–
Household income per capita
Quartile 1 (lowest)	21.18	–	20.06	–
Quartile 2	23.71	–	24.64	–
Quartile 3	26.23	–	26.28	–
Quartile 4 (highest)	28.88	–	29.03	–
Self-perceived income priority
Not very important)	58.18	–	50.66	–
Very important)	41.82	–	49.34	–
Community median income (RMB)	9041.1	4997	5917.13	3738.45
Community Gini coefficient	0.41	0.12	0.4	0.11

Table 3. Multilevel linear regression model of allostatic load.

	2009			2006 (lagged effect)
	Coefficient	SE	p	Coefficient	SE	p
Community level
Gini X 10	0.081	0.034	.016	0.106	0.04	.008
Median income per capita (K)	0.026	0.009	.006	0.012	0.014	.398
Individual level
Age	0.045	0.002	<.001	0.045	0.003	<.001
Male (ref = female)	−0.082	0.049	.097	−0.212	0.058	<.001
Marital status (ref = single)
Married	0.11	0.11	.317	−0.045	0.157	.773
Divorced/separated/widowed	0.087	0.146	.55	−0.121	0.198	.543
Urban (ref = rural)	−0.015	0.087	.865	0.1	0.101	.321
Education (ref = no schooling)
Elementary	0.038	0.078	.63	−0.088	0.088	.318
Middle school	−0.02	0.078	.794	−0.06	0.089	.5
High school or equivalent	−0.056	0.091	.541	0.061	0.103	.552
College or above	−0.173	0.138	.211	−0.189	0.175	.279
Household income per capita (ref = quartile 1)
Quartile 2	−0.088	0.732	.226	−0.043	0.085	.615
Quartile 3	−0.018	0.074	.805	0.027	0.087	.757
Quartile 4 (highest)	0.139	0.08	.083	0.376	0.096	<.001

Table 4. Multilevel linear regression model of allostatic load (subsample analysis).

	2009			2006 (lagged effect)
	Community median income (low)	Community median income (medium)	Community median income (high)	Community median income (low)	Community median income (medium)	Community median income (high)
	Coefficient (SE)	Coefficient (SE)	Coefficient (SE)	Coefficient (SE)	Coefficient (SE)	Coefficient (SE)
Community level
Gini X 10	0.174 (0.060)**	0.064 (0.056)	0.006 (0.054)	0.127 (0.064)*	0.064 (0.066)	0.118 (0.072)
Median income per capita (K)	−0.041 (0.074)	0.094 (0.061)	−0.018 (0.014)	0.125 (0.113)	0.339 (0.104)**	0–0.032 (0.205)
Individual level
Age	0.041 (0.004)***	0.046 (0.004)***	0.049 (0.004)***	0.045 (0.005)***	0.044 (0.005)***	0.049 (0.005)***
Male (ref = female)	−0.288 (0.916)**	−0.277 (0.084)**	0.215 (0.081)**	−0.399 (0.109)***	−0.411 (0.097)***	0.123 (0.098)
Marital status (ref = single)
Married	0.024 (0.194)	0.215 (0.192)	0.097 (0.185)	−0.041 (0.294)	−0.040 (0.259)	−0.140 (0.267)
Divorced/separated/widowed	0.089 (0.732)	0.028 (0.253)	0.194 (0.243)	−0.089 (0.360)	−0.098 (0.335)	−0.222 (0.335)
Urban (ref = rural)	−0.015 (0.207)	−0.147 (0.141)	0.028 (0.117)	−0.024 (0.231)	0.081 (0.157)	0.188 (0.147)
Education (ref = no schooling)
Elementary	0.200 (0.131)	0.035 (0.128)	−0.107 (0.147)	0.098 (0.147)	−0.183 (0.142)	−0.180 (0.172)
Middle school	0.032 (0.133)	0.079 (0.129)	−0.172 (0.141)	0.060 (0.152)	−0.113 (0.145)	−0.138 (0.169)
High school or equivalent	−0.009 (0.178)	0.097 (0.157)	−0.192 (0.151)	0.305 (0.207)	−0.003 (0.169)	0–0.031 (0.178)
College or above	−0.168 (0.411)	0.322 (0.335)	−0.349 (0.190)	0.219 (0.661)	−0.125 (0.350)	−0.345 (0.243)
Household income per capita (ref = quartile 1)
Quartile 2	−0.007 (0.105)	−0.143 (0.123)	−0.239 (0.181)	−0.192 (0.121)	0.162 (0.136)	−0.060 (0.228)
Quartile 3	0.196 (0.124)	0.024 (0.120)	−0.415 (0.165)*	−0.076 (0.143)	0.027 (0.137)	0.219 (0.211)
Quartile 4 (highest)	−0.111 (0.166)	0.123 (0.139)	−0.075 (0.161)	−0.013 (0.227)	0.403 (0.152)**	0.554 (0.207)**

***p < .001; **p < .01; *p < .05.

Table 5. Multilevel linear regression model of allostatic load (cross-level interaction with self-perceived income priority).

	Total sample	Community median income (low)	Community median income (medium)	Community median income (high)
	Coefficient (SE)	Coefficient (SE)	Coefficient (SE)	Coefficient (SE)
	2009
Cross-level interaction
Gini X income priority (ref = Gini X not very important)
Gini X very important	0.049 (0.040)	0.138 (0.065)*	−0.033 (0.076)	0.088 (0.073)
Gini X 10	0.058 (0.128)	0.101 (0.070)	0.054 (0.064)	−0.012 (0.057)
Income priority (ref = not very important)
Very important	−0.126 (0.171)	−0.716 (0.355)*	0.277 (0.330)	−0.143 (0.273)
	2006 (lagged effect)
Cross-level interaction
Gini X income priority (ref = Gini X not very important)
Gini X very important	0.028 (0.051)	0.073 (0.089)	−0.055 (0.087)	0.092 (0.100)
Gini X 10	0.094 (0.047)*	0.093 (0.078)	0.104 (0.078)	0.073 (0.082)
Income priority (ref = not very important)
Very important	−0.083 (0.213)	−0.314 (0.395)	0.230 (0.383)	−0.220 (0.370)

All models were adjusted for age, sex, marital status, residence, education, and household income quartiles. *p < .05.

Table

	Self-perceived income priority
	2009			2006
Household income per capita	Not very important	Very important	Chi-square (p)	Not very important	Very important	Chi-square (p)
Quartile 1 (lowest)	903 (56.97)	682 (43.03)	1.931 (.587)	464 (44.96)	568 (55.04)	29.154 (.000)
Quartile 2	1021 (57.62)	751 (42.38)	–	641 (49.81)	646 (50.19)	–
Quartile 3	1162 (58.98)	808 (41.02)	–	679 (49.45)	694 (50.55)	–
Quartile 4 (highest)	1270 (58.69)	894 (41.31)	–	841 (55.58)	672 (44.42)	–

Table

	Self-perceived income priority
	2009			2006
Income inequality quartiles	Not very important	Very important	Chi-square (p)	not very important	very important	Chi-square (p)
Quartile 1 (lowest)	1157 (57.79)	845 (41.21)	3.331 (.343)	745 (53.83)	639 (46.17)	9.586 (.022)
Quartile 2	1058 (57.34)	787 (42.66)	–	655 (48.38)	699 (51.62)	–
Quartile 3	1153 (59.90)	772 (40.10)	–	640 (50.20)	635 (49.80)	–
Quartile 4 (highest)	988 (57.48)	731 (42.52)	–	585 (49.08)	607 (50.92)	–