The Associations Between Serum Vitamins and Carotenoids with Chronic Obstructive Pulmonary Disease: Results from the NHANES

Figures & data

Figure 1 Flowchart of the sample selection from NHANES 2017–2018.

Table 1 Baseline Characteristics of Study Population According to COPD Weighted

Variables	Overall	Non-COPD	COPD	P value
	n=3487	n=3232 (92.69%)	n=255 (7.31%)
Age group (years) %				<0.0001
40—49	20.85	26.48	5.90
50—59	24.35	29.74	23.46
60—69	28.76	23.11	39.73
≥70	26.04	20.67	30.91
Gender (%)				0.3704
Male	48.84	47.45	44.44
Female	51.16	52.55	55.56
Race/Ethnicity (%)				0.0002
Mexican American	12.53	7.51	1.45
Other Hispanic	9.46	6.12	2.96
Non-Hispanic White	36.40	66.24	77.73
Non-Hispanic Black	23.03	10.21	6.94
Other Race - Including Multi-Racial	18.58	9.91	10.92
Education (%)				<0.0001
Less than 9th grade	10.18	4.43	3.61
9–11th grade	11.27	7.13	13.12
High school graduate/GED or equivalent	23.69	25.49	43.33
Some college or AA degree	30.97	30.53	29.27
College graduate or above	23.89	32.43	10.68
Diabetes (%)				<0.0001
Yes	21.77	15.81	33.28
No	78.23	84.19	66.72
Smoked at least 100 cigarettes in life (%)				<0.0001
Yes	45.05	41.57	87.83
No	54.95	58.43	12.17
Ever had a drink or any kind of alcohol (%)				0.0384
Yes	83.91	92.77	96.41
No	16.09	7.23	3.59
Income to poverty ratio	2.63 ±1.61	3.31 ± 1.58	2.45 ± 1.69	<0.0001
BMI	30.09±7.07	30.16 ± 6.78	30.18 ± 8.22	0.9781
Moderate physical activity (%)				0.0308
Yes	61.83	44.82	52.05
No	38.17	55.18	47.95
Vitamin C (mg/dL)	0.91±0.53	0.94 ± 0.52	0.74 ± 0.56	<0.0001
Alpha-tocopherol (ug/dL)	1319.71±476.57	1356.53 ± 476.72	1186.92 ± 355.91	<0.0001
Alpha-carotene (ug/dL)	5.55±9.25	5.40 ± 7.51	2.93 ± 3.39	0.0001
Trans-beta-carotene (ug/dL)	22.46±26.77	21.59 ± 24.48	13.45 ± 12.02	<0.0001
Cis-beta-carotene (ug/dL)	1.26±1.42	1.17 ± 1.25	0.81 ± 0.56	<0.0001
25OHD2+25OHD3 (nmol/L)	74.55±33.82	79.86 ± 32.08	80.23 ± 40.09	0.8663

Table 2 The Relationship Between Adjusted Serum Vitamins, Carotenoids and COPD

	Crude Model (Model 1)	Minimally Adjusted Model (Model 2)	Fully Adjusted Model (Model 3)
Vitamin C (mg/dL)
Categories
Tertile1 (0.0212–0.668)	Reference	Reference	Reference
Tertile2 (0.669–1.09)	0.46 (0.34, 0.63)	0.51 (0.37, 0.69)	0.78 (0.54, 1.14)
Tertile3 (1.1–6.32)	0.38 (0.28, 0.53)	0.30 (0.22, 0.43)	0.51 (0.35, 0.77)
P for trend	<0.0001	<0.0001	0.0012
Alpha-tocopherol (ug/dL)
Categories
Tertile1 (325–1080)	Reference	Reference	Reference
Tertile2 (1090–1390)	0.58 (0.43, 0.78)	0.56 (0.41, 0.77)	0.61 (0.42, 0.88)
Tertile3 (1400–5120)	0.38 (0.27, 0.53)	0.30 (0.21, 0.42)	0.36 (0.24, 0.55)
P for trend	<0.0001	<0.0001	<0.0001
Alpha-carotene (ug/dL)
Categories
Tertile1 (0.5–2.01)	Reference	Reference	Reference
Tertile2 (2.02–4.92)	0.45 (0.33, 0.61)	0.45 (0.32, 0.61)	0.55 (0.38, 0.80)
Tertile3 (34.93–195)	0.18 (0.12, 0.27)	0.21 (0.13, 0.32)	0.54 (0.33, 0.88)
P for trend	<0.0001	<0.0001	0.0129
Trans-beta-carotene (ug/dL)
Categories
Tertile1 (0.6–9.54)	Reference	Reference	Reference
Tertile2 (9.55–21.4)	0.41 (0.30, 0.56)	0.39 (0.28, 0.54)	0.49 (0.33, 0.72)
Tertile3 (21.5–415)	0.29 (0.20, 0.41)	0.28 (0.20, 0.41)	0.56 (0.36, 0.86)
P for trend	<0.0001	<0.0001	0.0135
Cis-beta-carotene (ug/dL)
Categories
Tertile1 (0.495–0.79)	Reference	Reference	Reference
Tertile2 (0.80–1.4)	0.47 (0.33, 0.66)	0.40 (0.28, 0.58)	0.56 (0.37, 0.85)
Tertile3 (1.4–23.1)	0.29 (0.19, 0.45)	0.25 (0.16, 0.39)	0.51 (0.31, 0.86)
P for trend	<0.0001	<0.0001	0.0049
25OHD2+25OHD3 (nmol/L)
Categories
Tertile1 (11.4–58.7)	Reference	Reference	Reference
Tertile2 (58.8–84.2)	0.91 (0.65, 1.26)	0.73 (0.51,1.02)	0.77 (0.52, 1.16)
Tertile3 (84.3–422)	1.25 (0.92, 1.70)	0.71 (0.51, 0.99)	0.89 (0.60, 1.32)
P for trend	0.1217	0.0591	0.6673

Notes: In sensitivity analysis, Serum level was converted from a continuous variable to a categorical variable (tertiles). Model 1: No adjustment for covariates. Model 2: Adjusted for gender, age, and race. Model 3: Adjusted for gender, age, race, education level, body mass index, income status, smoking status, drinking status, diabetes status and moderate physical activity.

Figure 2 Smooth curve Fitting Detected A nonlinear negative relationship between serum vitamins, carotenoids, and COPD was detected by the generalized additive model. (A) The relationship between Vitamin C and COPD. (B) The relationship between Alpha-tocopherol and COPD. (C)The relationship between Alpha-carotene and COPD. (D) The relationship between Trans-beta-carotene and COPD. (E) The relationship between Cis-beta-carotene and COPD.

Table 3 Subgroup Analysis for the Association Between Serum Vitamins, Carotenoids, and COPD

COPD		OR (95% CI)	P for Interaction
A. Vitamin C (mg/dL)
Gender			0.3328
Male	n=1703	0.85 (0.56, 1.27)
Female	n=1784	0.63 (0.41, 0.97)
Age group (years)			0.4837
40—49	n=727	1.38 (0.31, 6.09)
50—59	n=849	0.47 (0.21, 1.02)
60—69	n=1003	0.64 (0.36, 1.11)
≥70	n=908	0.82 (0.53, 1.28)
Diabetes			0.5038
Yes	n=759	0.62 (0.37, 1.05)
No	n=2728	0.77 (0.54, 1.09)
Smoked at least 100 cigarettes in life			0.6698
Yes	n=1571	0.75 (0.54, 1.03)
No	n=1916	0.62 (0.29, 1.33)
Ever had a drink or any kind of alcohol			0.5453
Yes	n=2926	0.74 (0.54, 1.01)
No	n=561	0.50 (0.15, 1.73)
Moderate physical activity			0.8678
Yes	n=1331	0.70 (0.45, 1.08)
No	n=2156	0.73 (0.49, 1.08)
B. Alpha-tocopherol (ug/dL)
Gender			0.0165
Male	n=1703	1.00 (1.00, 1.00)
Female	n=1784	1.00 (1.00, 1.00)
Age group (years)			0.0152
40—49	n=727	1.00 (0.99, 1.00)
50—59	n=849	1.00 (1.00, 1.00)
60—69	n=1003	1.00 (1.00, 1.00)
≥70	n=908	1.00 (1.00, 1.00)
Diabetes			0.8106
Yes	n=759	1.00 (1.00, 1.00)
No	n=2728	1.00 (1.00, 1.00)
Smoked at least 100 cigarettes in life			0.4515
Yes	n=1571	1.00 (1.00, 1.00)
No	n=1916	1.00 (1.00, 1.00)
Ever had a drink or any kind of alcohol			0.2928
Yes	n=2926	1.00 (1.00, 1.00)
No	n=561	1.00 (1.00, 1.00)
Moderate physical activity			0.3058
Yes	n=1331	1.00 (1.00, 1.00)
No	n=2156	1.00 (1.00, 1.00)
C. Alpha-carotene (ug/dL)
Gender			0.2561
Male	n=1703	0.90 (0.82, 0.99)
Female	n=1784	0.96 (0.90, 1.03)
Age group (years)			0.2042
40—49	n=727	0.98 (0.85, 1.14)
50—59	n=849	0.79 (0.63, 1.00)
60—69	n=1003	0.90 (0.80, 1.01)
≥70	n=908	0.97 (0.92, 1.02)
Diabetes			0.9842
Yes	n=759	0.93 (0.83, 1.05)
No	n=2728	0.94 (0.88, 1.00)
Smoked at least 100 cigarettes in life			0.5476
Yes	n=1571	0.93 (0.87, 1.00)
No	n=1916	0.97 (0.88, 1.06)
Ever had a drink or any kind of alcohol			0.6450
Yes	n=2926	0.94 (0.88, 1.00)
No	n=561	0.97 (0.88, 1.07)
Moderate physical activity			0.6216
Yes	n=1331	0.92 (0.84, 1.01)
No	n=2156	0.95 (0.88, 1.01)
D. Trans-beta-carotene (ug/dL)
Gender			0.8235
Male	n=1703	0.98 (0.96, 1.00)
Female	n=1784	0.98 (0.97, 1.00)
Age group (years)			0.6008
40—49	n=727	0.96 (0.87, 1.06)
50—59	n=849	0.96 (0.92, 1.00)
60—69	n=1003	0.98 (0.96, 1.01)
≥70	n=908	0.98 (0.97, 1.00)
Diabetes			0.1061
Yes	n=759	1.00 (0.97, 1.02)
No	n=2728	0.97 (0.96, 0.99)
Smoked at least 100 cigarettes in life			0.8973
Yes	n=1571	0.98 (0.97, 1.00)
No	n=1916	0.98 (0.96, 1.01)
Ever had a drink or any kind of alcohol			0.2536
Yes	n=2926	0.98 (0.97, 1.00)
No	n=561	0.96 (0.92, 1.01)
Moderate physical activity			0.1640
Yes	n=1331	0.99 (0.97, 1.01)
No	n=2156	0.97 (0.95, 0.99)
E. Cis-beta-carotene (ug/dL)
Gender			0.1575
Male	n=1703	0.52 (0.32, 0.87)
Female	n=1784	0.80 (0.58, 1.10)
Age group (years)			0.1335
40—49	n=727	0.01 (0.00,16.61)
50—59	n=849	0.39 (0.15, 1.02)
60—69	n=1003	0.74 (0.41, 1.31)
≥70	n=908	0.78 (0.56, 1.08)
Diabetes			0.3118
Yes	n=759	0.80 (0.48, 1.34)
No	n=2728	0.58 (0.40, 0.83)
Smoked at least 100 cigarettes in life			0.8715
Yes	n=1571	0.68 (0.49, 0.95)
No	n=1916	0.72 (0.41, 1.25)
Ever had a drink or any kind of alcohol			0.3219
Yes	n=2926	0.72 (0.53, 0.98)
No	n=561	0.47 (0.19, 1.17)
Moderate physical activity			0.4853
Yes	n=1331	0.74 (0.51, 1.09)
No	n=2156	0.61 (0.41, 0.92)
F. 25OHD2+25OHD3(nmol/L)
Gender			0.3189
Male	n=1703	1.00 (0.99, 1.01)
Female	n=1784	1.00 (1.00, 1.01)
Age group (years)			0.9886
40—49	n=727	1.00 (0.97, 1.03)
50—59	n=849	1.00 (0.99, 1.01)
60—69	n=1003	1.00 (0.99, 1.01)
≥70	n=908	1.00 (0.99, 1.01)
Diabetes			0.2614
Yes	n=759	1.00 (0.99, 1.00)
No	n=2728	1.00 (1.00, 1.01)
Smoked at least 100 cigarettes in life			0.3150
Yes	n=1571	1.00 (0.99, 1.00)
No	n=1916	1.01 (1.00, 1.02)
Ever had a drink or any kind of alcohol			0.0857
Yes	n=2926	1.01 (1.00, 1.02)
No	n=561	0.98 (0.95, 1.01)
Moderate physical activity			0.1480
Yes	n=1331	1.00 (0.99, 1.00)
No	n=2156	1.00 (1.00, 1.01)

Data Sharing Statement

The study utilized publicly available datasets. These statistics can be accessed at www.cdc.gov/nchs/nhanes/.