Table 4.

—Clinical and Biochemical Characteristics of Study Cohort by AAT Deficiency Category

	AAT Phenotype Combination
Characteristic	Moderate Deficiency	Mild Deficiency	Normal
Total Number	4	7	79
AAT characteristics
AAT phenotype combinations	PiMZ, PiSZ	PiMS, PiSS	PiMM
Serum AAT level, μmol/L	14.9 ± 3.2a	18.4 ± 2.6	23.9 ± 3.0
Demographic characteristics
Male sex	100	100	98
White race	100	71	86
Age, y	46.1 ± 6.1	38.7 ± 4.4	40.2 ± 7.3
Ex-smokers	25	14	25
EMS work assignment on September 11, 2001	0	29	10
High WTC exposure intensityb	75	71	65
FDNY tenure length on September 11, 2001, y	20.0 ± 6.4c	11.5 ± 4.9	10.9 ± 8.4

Data are presented as mean ± SD or %, unless otherwise indicated. Pi = protease inhibitor. See Table 1 and 2 legends for expansion of abbreviations.

^aP < .001, Kruskal-Wallis test.

^bArrived at WTC site morning of September 11, 2001.

^cP < .05, comparing workers with and without mildly AAT deficiency to workers with moderately AAT deficiency, t test.