Vitamin d deficiency and metabolic syndrome: The joint effect on cardiovascular and all-cause mortality in the United States adults

Table 1 Characteristics of participants at baseline

	Serum 25(OH)D concentrations									P value
	< 20 ng/mL			20 to 29 ng/mL			≥ 30 ng/mL
	No.	mean, %	(SE)	No.	mean, %	(SE)	No.	mean, %	(SE)
MetS, %										< 0.001
No	2640	64.7		2230	70.8		1276	79.3
Yes	1394	35.3		1089	29.2		465	20.7
Age, yr	4034	45.8	(0.6)	3319	44.7	(0.6)	1741	40.3	(0.6)	< 0.001
Waist circumference, cm	4034	94.2	(0.4)	3319	92.2	(0.3)	1741	88.3	(0.4)	< 0.001
Body mass index, kg/m2	4033	27.8	(0.2)	3318	26.5	(0.1)	1739	25.0	(0.1)	< 0.001
Systolic BP, mmHg	4034	123.4	(0.6)	3319	122.0	(0.6)	1741	119.0	(0.6)	<0.001
Diastolic BP, mmHg	4034	74.7	(0.3)	3317	74.1	(0.3)	1741	72.9	(0.4)	< 0.001
Triglycerides, mg/dL	4034	138.9	(4.1)	3319	136.4	(2.6)	1741	126.5	(3.8)	< 0.001
HDL-C, mg/dL	4034	51.0	(0.5)	3319	49.3	(0.4)	1741	51.5	(0.6)	< 0.001
Glucose, mg/dL	4034	100.7	(0.7)	3319	98.4	(0.5)	1741	94.7	(0.4)	< 0.001
Categorical variable, %
Sex, male, %	1561	38.3		178	51.9		975	55.4		< 0.001
Race/ethnicity, %										< 0.001
NHW	894	55.1		1557	79.7		1213	92.0
NHB	1788	25.8		575	6.0		139	1.9
Others	1352	19.1		1187	14.3		389	6.1
Region										< 0.001
Northeast	490	15.8		429	20.6		303	26.7
Midwest	651	18.9		709	24.5		434	28.1
South	1933	40.3		1299	33.2		685	29.1
West	960	25.0		882	21.6		319	16.1
Education level										0.001
< High school	930	13.1		818	11.8		355	8.2
High school	1971	49.2		1532	45.8		788	46.1
> High school	1113	37.7		949	42.4		592	45.6
Smoking										0.07
Never	2562	62.1		2230	63.9		1130	62.5
Former	193	5.5		191	6.0		105	4.0
Current	1279	32.4		898	30.2		506	33.5
Alcohol consumption, yes	1704	44.8		1592	55.9		910	63.7		< 0.001
Exercise, yes										0.13
More activity	559	14.1		475	16.3		287	18.4
About the same	2433	58.3		1998	56.2		1005	52.7
Less activity	1040	27.6		841	27.5		445	28.9
Health conditions
Hypertension, yes	1489	36.5		1129	29.6		565	25.5		< 0.001
Diabetes mellitus	465	9.3		312	6.7		105	3.3		< 0.001
CVD	278	6.3		252	5.3		124	3.4		0.001

Weighted mean and percentage are estimated because NHANES III applied a complex, multistage, probability sampling design. SE: Standard error; MetS: Metabolic syndrome; BP: Blood pressure; HDL-C: High-density lipoprotein cholesterol; NHW: Non-Hispanic White; NHB: Non-Hispanic Black; Others: Including all the other race/ethnicity groups; CVD: Cardiovascular disease included those with coronary heart disease, heart failure, or stroke.