Background: Inhaled corticosteroids have the potential
to produce upper-airway side effects such as hoarseness. As new
compounds and delivery devices are developed and compared, it is
difficult to quantify their adverse upper-airway effects.
Objective: We undertook the following study to test the
ability of an acoustic analysis technique to quantify changes in vocal
function in steroid-naive patients with asthma who receive inhaled
beclomethasone dipropionate (BDP), 1,000 μg/d for 4 months.
Methods: Patients self-administered one of four regimens of
inhaled BDP. Group 1 patients received one 250-μg puff qid via
metered-dose inhaler (MDI); group 2 patients received one 250-μg puff
qid via MDI with a holding chamber; group 3 patients received
two 250-μg puffs bid via MDI; and group 4 patients received two
250-μg puffs bid via MDI with a holding chamber. A smaller cohort of
nonsmoking asthmatic patients was managed without steroid intervention
for 4 months. At baseline and again at 8 weeks and 16 weeks after the
initiation of BDP treatment, patients underwent spirometry and
methacholine challenge. At baseline and again at 2, 4, 8, 12, and 16
weeks, patients underwent voice recording for analysis of voice
parameters. The recorded vowels were low-pass filtered (10 KHz),
digitized (22 KHz), and analyzed by software to obtain two acoustic
measures: (1) jitter, the cycle-to-cycle variation in the time period
of the voice signal; and (2) shimmer, the cycle-to-cycle variation in
voice signal amplitude.
Results: We recruited 77
patients for randomization to inhaled steroid therapy and 10 patients
who continued to receive only occasional inhaled bronchodilator
therapy. In all active treatment groups, FEV1, FVC, and
provocative concentration of methacholine causing a 20% fall in
FEV1 improved significantly after BDP treatment. Mean
jitter scores, a measurement of variation in voice pitch, were not
significantly influenced by BDP treatment. However, mean shimmer
scores, a reflection of perturbation in vocal amplitude, fell
significantly (p < 0.05) in the active treatment groups. These
reductions in shimmer scores were not significantly different in the
active treatment groups. Shimmer scores in the bronchodilator-treated
group were unchanged during the 16 weeks of follow-up.
Conclusions: Our data show that a simple and noninvasive
acoustic analysis of voice is sensitive to subclinical changes
associated with inhaled corticosteroid therapy. We have shown that
1,000 μg/d of inhaled BDP actually improves specific acoustic
measures of voice in patients with inadequately controlled asthma.
These improvements were uninfluenced by dosing schedule and whether a
spacing chamber was used.