Table 2.

The association between breathing difficulty and varicose veins.

Variables	OR	95% CI	P-value
Breathing difficulty
No (ref)	–
Moderate	1.357	1.228–1.499	<0.0001
Severe	1.623	1.403–1.877	<0.0001
P for trend	P-value <0.0001
Gender
Women (ref)	–
Men	0.307	0.272–0.347	<0.0001
Vegetarian diet
No (ref)	–
Yes	1.003	0.874–1.151	0.9709
Age
Age < 50 (ref)	–
50 ≤ Age ≤ 70	1.061	0.961–1.171	0.2396
Cigarette smoking
No (ref)	–
Yes	0.791	0.677–0.926	0.0034
Alcohol intake
No (ref)	–
Yes	0.974	0.794–1.196	0.8041
Exercise
No (ref)	–
Yes	0.928	0.845–1.019	0.1182
BMI categories
Normal weight (ref)	–
Underweight	0.697	0.534–0.910	0.0080
Overweight	0.992	0.892–1.103	0.8822
Obesity	0.883	0.777–1.004	0.0575
Educational level
Under elementary school (ref)	–
Junior and senior school	1.280	1.026–1.597	0.0290
University and above	1.340	1.069–1.679	0.0110
Job type
Non-prolonged standing (ref)	–
Prolonged standing	1.279	1.167–1.402	<0.0001
Hypertension
No (ref)	–
Yes	0.859	0.754–0.978	0.0219
Diabetes
No (ref)	–
Yes	0.802	0.669–0.960	0.0160