TABLE 4.

Associations between concentrations of selected serum antioxidants (per 1-SD increase) and MetS components: multiple logistic regression models (NHANES 2001–2006)¹²

	MetS binary components
	All		Men		Women
OR	95% CI	OR	95% CI	OR	95% CI
NCEP ATP III components4
Abdominal obesity	n = 4218		n = 2053		n = 2165
Total retinol+retinyl esters, per 0.66 μmol/L	0.883	(0.79; 0.97)	0.823	(0.70; 0.95)	0.92	(0.79; 1.07)
Total carotenoids, per 0.73 μmol/L	0.583	(0.51; 0.65)	0.593	(0.50; 0.68)	0.603	(0.49; 0.74)
Vitamin E, per 14.6 μmol/L	1.03	(0.92; 1.15)	0.93	(0.78; 1.11)	1.09	(0.90; 1.31)
Hypertriglyceridemia	n = 4322		n = 2099		n = 2223
Total retinol+retinyl esters, per 0.66 μmol/L	1.813	(1.64; 2.01)	1.933	(1.61; 2.30)	1.763	(1.53; 2.01)
Total carotenoids, per 0.73 μmol/L	0.393	(0.34; 0.45)	0.383	(0.30; 0.47)	0.403	(0.32; 0.50)
Vitamin E, per 14.6 μmol/L	3.143	(2.51; 3.92)	3.813	(2.69; 5.39)	2.783	(2.13; 3.64)
Low HDL-C	n = 4322		n = 2099		n = 2223
Total retinol+retinyl esters, per 0.66 μmol/L	0.763	(0.65; 0.89)	0.673	(0.54; 0.84)	0.823	(0.68; 1.00)
Total carotenoids, per 0.73 μmol/L	0.653	(0.55; 0.77)	0.673	(0.50; 0.88)	0.653	(0.53; 0.81)
Vitamin E, per 14.6 μmol/L	1.01	(0.85; 1.22)	0.88	(0.58; 1.38)	1.12	(0.92; 1.38)
High blood pressure	n = 3071		n = 1510		n = 1561
Total retinol+retinyl esters, per 0.66 μmol/L	1.09	(0.99; 1.21)	0.99	(0.85; 1.10)	1.263	(1.06; 1.49)
Total carotenoids, per 0.73 μmol/L	0.783	(0.68; 0.90)	0.773	(0.61; 0.97)	0.733	(0.59; 0.91)
Vitamin E, per 14.6 μmol/L	0.89	(0.75; 1.04)	0.80	(0.62; 1.04)	1.00	(0.79; 1.26)
Hyperglycemia	n = 4315		n = 2094		n = 2221
Total retinol+retinyl esters, per 0.66 μmol/L	1.03	(0.92; 1.15)	1.01	(0.87; 1.19)	1.01	(0.85; 1.20)
Total carotenoids, per 0.73 μmol/L	0.803	(0.70; 0.92)	0.92	(0.80; 1.07)	0.733	(0.62; 0.87)
Vitamin E, per 14.6 μmol/L	0.95	(0.85; 1.05)	0.94	(0.78; 1.13)	0.93	(0.74; 1.16)
Other components4
Elevated HOMA-IR	n = 4305		n = 2089		n = 2216
Total retinol+retinyl esters, per 0.66 μmol/L	0.99	(0.89; 1.10)	0.92	(0.79; 1.15)	1.08	(0.91; 1.29)
Total carotenoids, per 0.73 μmol/L	0.623	(0.55; 0.70)	0.653	(0.55; 0.77)	0.613	(0.51; 0.73)
Vitamin E, per 14.6 μmol/L	0.89	(0.75; 1.04)	0.95	(0.79; 1.15)	0.753	(0.60; 0.95)
Elevated CRP	n = 4322		n = 2099		n = 2223
Total retinol+retinyl esters, per 0.66 μmol/L	0.513	(0.36; 0.72)	0.423	(0.22; 0.83)	0.593	(0.38; 0.93)
Total carotenoids, per 0.73 μmol/L	0.353	(0.22; 0.55)	0.323	(0.15; 0.68)	0.363	(0.21; 0.62)
Vitamin E, per 14.6 μmol/L	1.29	(0.93; 1.78)	1.46	(0.89; 2.40)	1.34	(0.87; 2.07)
Hyperuricemia	n = 3284		n = 1580		n = 1704
Total retinol+retinyl esters, per 0.66 μmol/L	1.403	(1.24; 1.60)	1.303	(1.07; 1.58)	1.513	(1.21; 1.87)
Total carotenoids, per 0.73 μmol/L	0.583	(0.46; 0.74)	0.663	(0.47; 0.91)	0.493	(0.36; 0.68)
Vitamin E, per 14.6 μmol/L	0.88	(0.73; 1.05)	0.81	(0.63; 1.02)	0.89	(0.69; 1.15)

¹Values are OR with 95% CI. Sampling design complexity is taken into account in all analyses. Vitamin C was not included in this analysis due to an appreciable drop in sample size (vitamin C available only for the 2003–2004 and 2005–2006 waves of NHANES). A sensitivity analysis was conducted to examine the association between quartiles of vitamin C and MetS (and its components). See Table 5 and Figure 1 results section.

²Models included the 3 main antioxidant status exposures and adjusted for socio-demographic factors: age, sex, race/ethnicity, marital status, educational level, PIR, and other potential confounders: lifestyle and health-related factors (smoking status, PA: Met⋅h⋅wk⁻¹, recoded as 0 to <5, 5–10, >10) and dietary intakes (total energy intake, alcohol, caffeine, β-carotene, vitamin C, vitamin E ,and dietary supplement use), serum levels of folate, tHcy, vitamin B-12, 25(OH)D, total cholesterol, and TG. Note that in models with hypertriglyceridemia as the outcome, only serum cholesterol was controlled for among serum lipids.

³ < 0.05 for null hypothesis that Log_e(OR) = 0 based on Wald test.

⁴See Methods for definition of each component.