Exercise performance and dynamic hyperinflation in lymphangioleiomyomatosis.
BACKGROUND
Lymphangioleiomyomatosis (LAM) is characterized by exercise performance impairment. Although airflow limitation is common, no previous studies have evaluated the prevalence and impact of dynamic hyperinflation (DH) in LAM.


OBJECTIVE
To investigate the dynamic responses during maximal exercise and the prevalence, predictors, and repercussions of DH in LAM.


METHODS
Forty-two patients with LAM performed symptom-limited incremental cycle exercise and pulmonary functions tests (PFTs) and were compared with 10 age-matched healthy women. Dyspnea intensity, inspiratory capacity, oxygen saturation, and cardiac, metabolic, and respiratory variables were assessed during exercise. Patients with LAM also performed a 6-minute walk test (6MWT).


RESULTS
Patients with LAM had higher baseline dyspnea, poorer quality of life, obstructive pattern, air trapping, and reduced diffusing capacity of carbon monoxide in PFTs. Although they had the same level of regular physical activity, their maximal exercise performance was reduced and was associated with ventilatory limitation, greater desaturation, and dyspnea. The prevalence of DH was high in LAM (55%), even in patients with mild spirometric abnormalities, and was correlated with airflow obstruction, air trapping, and diffusing capacity of carbon monoxide. Compared with the non-DH subgroup, the patients who developed DH had a ventilatory limitation contributing to exercise cessation on cycling and higher desaturation and dyspnea intensity during the 6MWT.


CONCLUSIONS
Ventilatory limitation and gas exchange impairment are important causes of exercise limitation in LAM. DH is frequent in LAM, even in patients with mild spirometric abnormalities. DH was associated with the severity of disease, higher dyspnea, and lower oxygen saturation. In the 6MWT, desaturation and dyspnea were greater in patients with DH.
Pulmonary Division, Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil. bruno.guedes2@terra.com.br
Bruno G
BG
Baldi
André L P
AL
Albuquerque
Suzana P
SP
Pimenta
João M
JM
Salge
Ronaldo A
RA
Kairalla
Carlos R R
CR
Carvalho
D000328:Adult; D004417:Dyspnea / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D005080:Exercise Test / Q000379:methods / Q000706:statistics & numerical data; D017079:Exercise Tolerance; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D007320:Inspiratory Capacity; D018192:Lymphangioleiomyomatosis / Q000150:complications* / Q000503:physiopathology*; D005082:Physical Exertion; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications* / Q000503:physiopathology*; D012129:Respiratory Function Tests / Q000379:methods / Q000706:statistics & numerical data