Table 1.

Baseline Characteristics of participants by RA among U.S. adults, NHANES 2003–2018

Characteristic	Non-RA	RA	P value
N	17330	1008
Age(years)	41.59 ± 14.92	54.66 ± 13.65	< 0.001
Gender
Male	9314 (53.74%)	466 (46.28%)	0.002
Female	8016 (46.26%)	542 (53.72%)
Race/ethnicity, n (%)
Non-Hispanic White	12044 (69.50%)	687 (68.19%)	< 0.001
Non-Hispanic Black	1747 (10.08%)	157 (15.61%)
Mexican American	1512 (8.72%)	67 (6.61%)
Other race/multiracial	2027 (11.70%)	97 (9.59%)
Education level, n (%)
Less than high school	2010 (11.60%)	165 (16.39%)	< 0.001
High school	3750 (21.64%)	253 (25.07%)
More than high school	11,570 (66.76%)	590 (58.54%)
Diabetes, n (%)
Yes	1455 (8.39%)	182 (18.07%)	< 0.001
No	15,875 (91.61%)	826 (81.93%)
Family PIR	3.21 ± 1.62	2.73 ± 1.64	< 0.001
BMI	28.22 ± 6.43	30.31 ± 7.41	< 0.001
Energy (kcal/day)	2234.06 ± 886.38	2037.12 ± 847.83	< 0.001
Alcoholic ≥ 4 drinks/day (%)
Yes	13,165 (75.97%)	824 (81.70%)	0.002
No	4165 (24.03%)	184 (18.30%)
Smoked >  = 100 cigarettes in life (%)
Yes	7882 (45.49%)	632 (62.30%)	< 0.001
No	9447 (54.51%)	376 (37.70%)
Carbohydrate (g/day)	261.43 ± 114.06	236.72 ± 102.84	< 0.001
Fat (g/day)	85.55 ± 40.59	79.04 ± 38.27	< 0.001
Protein (g/day)	86.97 ± 37.33	78.48 ± 37.18	< 0.001
Total Mg (mg/day)	312.28 ± 137.54	285.79 ± 133.58	< 0.001
Total Cu (mg/day)	1.33 ± 0.82	1.22 ± 0.63	< 0.001
Total K (mg/day)	2757.02 ± 1136.06	2643.17 ± 1150.81	< 0.001

Continuous variables were presented as mean ± SD; Categorical variables were presented as n (%)

NHANES National Health and Nutrition Examination Survey, RA rheumatoid arthritis, BMI body mass index, PIR the ratio of family income to poverty, SD standard deviation, n numbers of subjects, % weighted percentage, Mg magnesium, Cu copper, K potassium