The association of human leukocyte antigen polymorphisms with disease severity and latency period in patients with silicosis

Table 1 Demographic data, exposure characteristics, and lung function tests for the severe and mild groups

	Severe group**	Mild group***	P	Mean
Subjects (n)	28	20	-	-
Age (years)	24.0 ± 9.5	23.4 ± 9.2	-	NS*
BMI	22.3 ± 2.7	22.5 ± 3.0	-	NS*
Total exposure duration (months)	35.7 ± 23.5	22.1 ± 21.1	0.004	Significant
Latency period (months)	58.1 ± 25.1	42.0 ± 30.6	0.044	Significant
Smoking (pack/years)	6.7 ± 2.3	5.9 ± 4.8	-	NS*
FEV₁ L	3.2 ± 0.8	3.8 ± 0.5	0.003	Significant
FEV₁% pred	80.0 ± 19.9	93.5 ± 21.1	0.003	Significant
FVC L	3.8 ± 0.9	4.6 ± 0.8	0.005	Significant
FVC% pred	81.6 ± 18.3	96.0 ± 24.9	0.004	Significant
FEV₁/FVC%	80.0 ± 9.0	84.7 ± 7.5	-	NS*

*NS, Not significant; **Severe, the cases with 1/1 or higher ILO profusion. ***Mild, the cases with1/0 or lower ILO profusion without any symptoms, but with proof of the disease on HRCT.