TABLE 4.
PATTERNS OF PULMONARY FUNCTION AT ENROLLMENT
| All Patients
|
|
Sporadic LAM
|
|
TSC-LAM
|
|
||
|---|---|---|---|---|---|---|---|
| Characteristic | n | % | n | % | n | % | p Value* |
| Normal spirometry | 74 | 33.9 | 57 | 30.7 | 17 | 53.1 | 0.013 |
| Obstruction | 125 | 57.3 | 113 | 60.8 | 12 | 37.5 | 0.014 |
| Mild (FEV1 > 70%pred) | 27 | 12.4 | 24 | 12.9 | 3 | 9.4 | 0.77 |
| Moderate (FEV1 ≥ 50 and ≥ 70%pred) | 43 | 19.7 | 41 | 22.0 | 2 | 6.3 | 0.052 |
| Severe (FEV1 < 50%pred) | 55 | 25.2 | 48 | 25.8 | 7 | 21.9 | 0.64 |
| Bronchodilator response | 37 | 17.1 | 31 | 16.8 | 6 | 18.8 | 0.80 |
| Hyperinflation | 12 | 6.3 | 11 | 6.9 | 1 | 3.3 | 0.69 |
| Restriction | 21 | 11.4 | 17 | 10.9 | 4 | 14.3 | 0.60 |
| Low diffusing capacity | 124 | 56.9 | 111 | 60.3 | 13 | 38.2 | 0.017 |
For definition of abbreviations, see Table 1.
Percentages are calculated on the basis of the number of subjects with information available, which included 218 spirometries, 217 bronchodilator responses, 190 lung volumes, and 218 diffusing capacities. Normal spirometry is defined by both FVC and FEV1/FVC ratio greater than or equal to the lower limit of normal (statistically determined lower limit of normal; mean predicted value – [1.645 × SE], i.e., the lower bound of a 90% confidence interval on the prediction regression equation). Obstruction is defined as an FEV1/FVC ratio that is less than the lower limit of normal. Bronchodilator response is defined as an increase in FEV1 of at least 12% and 200 ml. Hyperinflation is defined as a TLC value that is greater than the upper limit of normal (statistically determined upper limit of normal; mean predicted value + [1.645 × SE]). Restriction is defined as a TLC value that is less than the lower limit of normal. Low diffusing capacity is defined as a measurement below the predicted normal range (nonsmoker reference equations of Miller and coworkers [23]).
p values are for comparison between the two subgroups.