Endocrine Abstracts

Introduction: Acromegaly is a slowly progressing systemic disease that leads to numerous changes in metabolism and organ function. A large cross-sectional study showed signs of subclinical airway obstruction in female patients. We performed a longitudinal study of lung function testing to compare parameters of airway obstruction in male and female patients with acromegaly over time.

Methods: 40 patients with acromegaly (24 male, 16 female) underwent repeat lung function testing with a mean interval of 10.1 ± 4.3 years. Lung function parameters were converted to percentages of predicted values obtained from normative data to correct differences of absolute values for age, sex, height and weight. We investigated the impact of disease activity on changes of airway obstruction by categorizing patients as biochemically controlled if at the date of repeat testing random growth hormone levels were below ng/ml and IGF-I levels within the age and sex reference range of the assay used. We calculated group comparisons using an independent samples t-test with a significance threshold of 0.05 and interpreting p values below 0.1 as trend.

Results: While FEV₁, FEF₇₅, FEF₅₀, and FEF₂₅ did not differ significantly between male and female patients over time, we found a significant increase of total specific resistance in women (sR_tot; P = 0.014; men – 5.0%, women +30.2%). Furthermore, in women there is a trend for increased total airway resistance (R_tot; P = 0.078; men –3.6%, women +17.2%) as well as decreased peak expiratory flow (PEF; P = 0.096; men + 5.5%, women –10.4%). Changes in airway obstruction were unrelated to biochemical control of acromegaly.

Conclusion: Female patients with acromegaly seem to develop airway obstruction over time, regardless of disease activity. The mechanism of this change remains to be elucidated.