Table 2 Measures of pulmonary function in AS patients and controls

FVC (liters) mean (SD)

4.0 (1.2)

4.1 (1.0)

0.3 (0.14,0.45)

< 0.001^a

FVC%

97.2 (18.1)

104.9 (15.2)

< 0.001^b

FEV₁ (liters) mean (SD)

3.1 (0.9)

3.2 (0.9)

0.3 (0.18,0.43)

< 0.001^a

FEV₁%

89.8 (16.0)

98.5 (14.5)

< 0.001^b

PEF (liters/minute) mean (SD

464.7 (121.4)

469.1 (120.1)

20.5 (1,41.1)

0.05^a

PEF%

95.2 (17.6)

99.4 (16.6)

0.05^b

FEV₁/FVC%

76.5 (7.5)

77 (6.4)

0.38^b

Respiratory pattern

Normal n (%)

105 (71.4)

110 (90.9)

< 0.001^c

Restrictive pattern n (%)

27 (18.4)

0

< 0.001^c

Obstructive pattern n (%)

15 (10.2)

11 (9.1)

0.76^c