Acromegaly patients have higher lung volume
Lung volume is significantly higher in acromegaly patients than in controls, a new cross-sectional study of a large cohort has shown. Subclinical airway obstruction appears to be also present in female patients.
The study included 109 acromegaly patients (mean age 54.6±13.5 years; 51.4 percent female). Exclusion criteria included previous chronic or severe acute pulmonary diseases and impaired cardiac functions. All participants provided blood samples and were subjected to lung function tests.
Insulin-like growth factor 1 and growth hormone levels were measured from the blood samples. Lung function variables included maximal expiratory flow-volume loops, vital capacity (VC), forced expiratory volume in one second (FEV1), peak expiratory flow (PEF), airway resistance and residual volume (RV).
Lung volume, as measured by maximal VC, was significantly higher in acromegaly patients vs controls (p<0.001). Intrathoracic gas volume (p<0.001), total lung capacity (p=0.006) and RV (p<0.001) were also significantly higher in acromegaly patients.
PEF (p=0.01) and maximum expiratory flow when 75 percent of the forced VC (FVC) has been exhaled (FEV75; p<0.001) were significantly reduced in acromegaly patients, indicating airway obstruction. In contrast, FEV1 was significantly higher (p<0.001).
Acromegaly patients had significant hypoxemia (pO2; p<0.001) compared with normative data. However, only 5.6 percent (n=6) of the study sample had clinically relevant hypoxemia, four of whom were obese.
Analysis according to gender showed that males had significantly higher PEF (p=0.013), FEF25 (p=0.003) and FEF50 (p=0.001) flow rates compared with females. Moreover, while total airway resistance (Rtot) was not significantly increased in either gender, males had significantly lower Rtot (p=0.005) than females.