Burden of Metabolic Syndrome Among a Low-Income Population in China: A Population-Based Cross-Sectional Study

Figures & data

Figure 1 Flowchart of object selection. Of the 4222 residents who met the inclusion criteria, 3182 eligible individuals enrolled in this study, with the response rate of 75.4%. Finally, 3175 participants were included in this study after excluding seven residents with missing data.

Table 1 Characteristics of Study Participants by Sex

Category	Men	Women	Total
Total	1425 (44.8)	1752 (55.2)	3175 (100)
Age, means (SD), years	65.14 (7.91)	63.32 (7.88)	64.13 (7.94)
Age group, n (%):
45~54 years	161 (11.3)	298 (17.0)	459 (14.5)
55~64 years	567 (39.8)	739 (42.2)	1306 (41.1)
≥65 years	695 (48.8)	715 (40.8)	1410 (44.4)
Education level, n (%):
Illiterate	75 (5.3)	484 (27.6)	559 (17.6)
<high school	1185 (83.3)	1148 (65.5)	2333 (73.5)
≥High school	163 (11.5)	120 (6.8)	283 (8.9)
Incomes, n (%)
<2000 yuan	936 (65.8)	1141 (65.1)	2077 (65.4)
2000–6000 yuan	445 (31.3)	558 (31.8)	1003 (31.6)
>6000 yuan	42 (3.0)	53 (3.0)	95 (3.0)
Smoking status, n (%):
Never smoking	381 (26.8)	1676 (95.7)	2057 (64.8)
Now or ever smoking	1042 (73.2)	76 (4.3)	1118 (35.2)
Alcohol consumption, n (%):
Never drinking	665 (46.7)	1717 (98.0)	2382 (75.0)
Now or ever drinking	758 (53.3)	35 (2.0)	739 (25.0)
Physical activity, n (%)	867 (60.9)	1083 (61.8)	1950 (61.4)
Self-reported snoring, n (%)	754 (53.0)	882 (50.3)	1636 (51.5)
CVD, n (%)	256 (18.0)	256 (14.6)	512 (16.1)
BMI, means (SD), kg/m^2	25.46 (3.44)	26.28 (3.82)	25.91 (3.68)
BMI, n (%):
Normal or under weight	494 (34.7)	478 (27.4)	972 (30.6)
Overweight	617 (43.4)	764 (43.7)	1381 (43.5)
Obesity	311 (21.9)	505 (28.9)	816 (25.7)
WC, means (SD), cm	88.24 (9.68)	86.40 (9.56)	87.22 (9.66)
WHR, means (SD)	0.92 (0.06)	0.90 (0.07)	0.91 (0.00)
SBP, means (SD), mmHg	151.87 (20.20)	149.99 (19.66)	150.83 (19.92)
DBP, means (SD), mmHg	87.60 (11.02)	83.25 (10.35)	85.20 (10.87)
SUA, means (SD), µmol/L	329.90 (86.48)	274.66 (77.99)	298.07 (85.92)
Hyperuricemia, n (%)	204 (14.3)	252 (14.4)	456 (14.4)
FBG, means (SD), mmol/L	5.91 (1.54)	6.01 (1.64)	5.98 (1.60)
TC, means (SD), mmol/L	4.92 (0.87)	5.29 (0.93)	5.13 (0.92)
TG, means (SD), mmol/L	1.48 (1.28)	1.73 (1.28)	1.62 (1.29)
HDL-C, means (SD), mmol/L	1.38 (0.47)	1.40 (0.43)	1.39 (0.45)
LDL-C, means (SD), mmol/L	2.95 (0.82)	3.22 (0.92)	3.09 (0.89)

Abbreviations: SD, standard deviation; SBP, systolic blood pressure; DBP, diastolic blood pressure; BP, blood pressure; BMI, body mass index; WC, Waist circumference; FBG, fasting blood glucose; TC, total cholesterol; TG, triglycerides; HDL-C, high density lipoprotein cholesterol; LDL-C, low density lipoprotein cholesterol; WHR, waist-to-hip-ratio; SUA, serum uric acid.

Table 2 Characteristics of Metabolic Syndrome and Its Components

Category	Men	Women	P value	Total
MetS, n (%)	582 (40.9)	1093 (62.4)	<0.001	1675 (52.8)
Num. of MetS components, n (%)			<0.001
1	352 (25.8)	218 (12.7)		570 (18.0)
2	428 (31.4)	408 (23.7)		836 (26.3)
3	317 (23.3)	463 (26.9)		780 (24.6)
4	179 (13.1)	377 (21.9)		556 (17.5)
5	86 (6.3)	253 (14.7)		3339 (10.7)
MetS components, n (%)
Abdominal obesity	651 (45.7)	1316 (75.1)	<0.001	1967 (62.0)
Raised BP	1286 (90.4)	1549 (88.4)	0.076	2835 (89.3)
Raised FPG	675 (47.4)	840 (47.9)	0.775	1515 (47.7)
Reduced HDL-C	291 (20.4)	778 (44.4)	<0.001	1069 (33.7)
Elevated TG	402 (28.3)	713 (40.9)	<0.001	1115 (35.1)

Table 3 The Univariate Analysis of Influence Factors for Metabolic Syndrome

Categories	Non-MetS	MetS	P value
Sex:			<0.001
Men	841 (59.1)	582 (40.9)
Women	659 (37.6)	1093 (62.4)
Age, means (SD), years	64.4 (8.23)	63.89 (7.61)	0.029
Age group:			0.149
45~54 years	224 (48.8)	235 (51.2)
55~64 years	590 (45.2)	716 (54.8)
≥65 years	686 (58.7)	724 (51.3)
Education level, n (%):			0.001
Illiterate	226 (40.4)	333 (59.6)
<high school	1142 (48.9)	1191 (51.1)
≥High school	132 (46.6)	151 (53.4)
Incomes, n (%)			0.033
<2000 yuan	1016 (48.9)	1061 (51.1)
2000–6000 yuan	441 (44.0)	562 (56.0)
>6000 yuan	43 (45.3)	52 (54.7)
Now or ever smoking	636 (56.9)	482 (43.1)	<0.001
Now or ever drinking	471 (59.4)	322 (40.6)	<0.001
Physical activity, n (%)	911 (46.7)	1039 (53.3)	0.454
Self-reported snoring, n (%)	673 (41.1)	963 (58.9)	<0.001
BMI, means (SD), kg/m^2	24.14 (3.18)	27.50 (3.35)	<0.001
BMI, n (%):			<0.001
Normal or under weight	751 (77.3)	221 (22.7)
Overweight	595 (43.1)	786 (56.9)
Obesity	149 (18.3)	667 (81.7)
WHR, means (SD)	0.89 (0.06)	0.93 (0.06)	0.014
SUA, means (SD), µmol/L	287.37 (81.01)	307.66 (89.02)	0.002
Hyperuricemia, n (%)	144 (31.6)	312 (68.4)	<0.001
LDL-C, means (SD), mmol/L	3.03 (0.80)	3.16 (0.95)	<0.001

Table 4 Risk Factors of Metabolic Syndrome in Multivariate Analysis

Risk Factors	Reference	Crude OR (95% CI)	P	Adjusted OR (95% CI)*	P
Sex:	Men	1.00		1.00
Women		2.543 (2.204, 2.933)	<0.001	4.791 (3.597, 6.271)	<0.001
Age	–	0.987 (0.971, 1.004)	0.129	1.084 (0.989, 1.189)	0.084
Education level:	Illiterate	1.00		1.00
<high school		1.547 (1.262, 1.897)	<0.001	1.004 (0.788, 1.280)	0.972
≥High school		1.118 (0.960, 1.302)	0.151	1.189 (0.823, 1.717)	0.356
Incomes:	<2000 yuan	1.00		1.00
2000–6000 yuan		1.050 (0.665, 1.659)	0.833	0.981 (0.596, 1.615)	0.940
>6000 yuan		0.862 (0.551, 1.347)	0.514	0.876 (0.536, 1.434)	0.599
Smoking status:	Never smoking	1.00		1.00
Now or ever smoking		2.047 (1.744, 2.403)	<0.001	1.363 (1.035, 1.794)	0.028
Alcohol consumption:	Never drinking	1.00		1.00
Now or ever drinking		1.699 (1.409, 2.049)	<0.001	0.863 (0.667, 1.118)	0.250
BMI	–	1.349 (1.313, 1.386)	<0.001	2.565 (2.285, 2.879)	<0.001
WHR	–	1.140 (1.127, 1.152)	<0.001	1.929 (1.740, 2.138)	<0.001
Self-reported snoring	-	1.112 (0.855, 1.446)	0.427	1.221 (1.027, 1.451)	0.024
SUA	-	1.003 (1.002, 1.004)	<0.001	1.291 (1.178. 1.415)	<0.001
LDL-C	-	1.364 (1.257, 1.480)	<0.001	0.985 (0.903, 1.074)	0.731

Notes: *Adjustment for age, sex, education, income, smoking status, alcohol consumption, BMI, WHR, SUA, LDL-C and snore in multivariate analysis.

Table 5 The Sensitivity Analyses of the Association of Metabolic Syndrome with Relative Risk Factors

Risk Factors	Reference	Crude OR (95% CI)	P	Adjusted OR (95% CI)	P
Sex:	Men	1.00		1.00
Women		1.712 (1.363, 2.151)	<0.001	4.651 (3.410, 6.345)	<0.001
Age	–	0.988 (0.971, 1.001)	0.152	1.013 (0.999, 1.026)	0.062
Education level:	Illiterate	1.00		1.00
<High school		0.857 (0.658, 1.115)	0.250	0.909 (0.691, 1.194)	0.492
≥High school		0.958 (0.678, 1.338)	0.780	1.080 (0.803, 1.452)	0.613
Incomes:	<2000 yuan	1.00		1.00
2000–6000 yuan		1.257 (0.746, 2.117)	0.390	0.971 (0.572, 1.649)	0.914
>6000 yuan		0.890 (0.533, 1.487)	0.890	0.906 (0.535, 1.532)	0.712
Smoking status:	Never smoking	1.00		1.00
Now or ever smoking		1.450 (0.970, 2.166)	0.070	1.378 (1.013, 1.875)	0.041
Alcohol consumption:	Never drinking			1.00
Now or ever drinking		1.030 (0.508, 2.087)	0.935	0.808 (0.607, 1.076)	0.144
BMI	–	1.347 (1.289, 1.407)	<0.001	2.493 (2.201, 2.823)	<0.001
WHR	–	1.117 (1.101, 1.134)	<0.001	1.862 (1.665, 2.082)	<0.001
Self-reported snoring	-	1.631 (1.337, 1.991)	<0.001	1.239 (1.027, 1.451)	0.025
SUA	-	1.004 (1.002, 1.005)	<0.001	1.319 (1.192. 1.458)	<0.001
LDL-C	-	1.057 (0.891, 1.254)	0.521	1.004 (0.912, 1.105)	0.942

Notes: Adjustments for age, sex, education, income, smoking status, alcohol consumption, BMI, WHR, SUA, LDL-C and snore in multivariate analysis.