Table 2.

Baseline characteristics of the study subjects according to OA status.

	No OA (n = 10,401)	OA (n = 1055)	P value
Age (years)	44.94 ± 16.99	64.45 ± 13.63	< 0.001
Gender (%)			< 0.001
Male	51.96	34.41
Female	48.04	65.59
Race (%)			< 0.001
Non-Hispanic White	46.37	72.23
Non-Hispanic Black	19.86	12.04
Mexican American	25.33	10.52
Other Hispanic	4.64	1.90
Other ethnicity	3.79	3.32
Education (%)			0.003
Lower than high school	29.37	24.36
High school	23.03	24.74
More than high school	47.59	50.90
Physical activity (%)			< 0.001
Sedentary	21.85	28.63
Low	28.22	26.54
Moderate	18.54	18.48
High	31.39	26.35
Total protein (g/dL)	7.37 ± 0.48	7.20 ± 0.49	< 0.001
Total cholesterol (mg/dl)	200.50 ± 42.40	208.92 ± 41.51	< 0.001
HDL cholesterol (mg/dl)	51.93 ± 15.41	55.14 ± 17.07	< 0.001
Triglycerides (mg/dl)	141.95 ± 129.97	155.89 ± 109.26	< 0.001
Hemoglobin (g/dL)	14.46 ± 1.51	14.04 ± 1.39	< 0.001
Serum albumin (g/dL)	4.32 ± 0.33	4.21 ± 0.32	< 0.001
Calf circumference (cm)	38.18 ± 4.05	38.46 ± 4.26	0.058
Smoking status (%)			< 0.001
Non-smoker	53.10	46.35
Smoker	46.90	53.65

Mean ± SD for continuous variables and P value was calculated by Kruskal–Wallis test. % for Categorical variables and P value was calculated by weighted chi-square test.

OA osteoarthritis.