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Eight hypoxic male patients with stable chronic obstructive airways disease were submitted for combined anterior pituitary function testing. All subjects showed normal growth hormone and essentially normal cortisol responses to adequate hypoglycaemia, two subjects showed delayed responses of thyroid stimulating hormone to administered thyrotrophin releasing hormone and all had basal prolactin levels within normal limits. Basal levels of luteinising hormone were significantly lower than in the group of age-matched controls (p < 002) but there was a normal increment after the injection of gonadotrophin releasing hormone. Basal levels of follicle stimulating hormone were significantly lower than in the controls (p < 001), and there was also a reduced response from the pituitary after injection of gonadotrophin releasing hormone (p < 0-01). Resting levels of the thyroid hormones thyroxine and tri-iodothyronine were normal while the expected subnormal testosterone level was observed (p < 0 05). These results show that hypoxia can produce abnormalities of hypothalamic-pituitary function and that these are primarily located in the hypothalamicpituitary-testicular axis.While studying metabolic aspects of chronic obstructive airways disease (COAD), we have recently found reduced serum testosterone values in affected men,' and have been able to demonstrate an association between severity of hypoxia and degree of testosterone suppression.2 Theoretical consequences of endocrine abnormalities have been discussed in these communications with particular reference to the difference in body habitus between overweight chronic bronchitic "blue bloaters" and thin emphysematous "pink puffers." Though such hormonal changes had not previously been described in patients with COAD, reduced urinary 17-ketosteroid production had already been noted at high altitude3 and in emphysema.4 We have postulated that hypoxia produces low androgen output by suppressing hypothalamic-pituitary function. However, decreased response of testosterone secretion after testicular stimulation by injection of human chorionic gonadotrophin (HCG)

1. We have measured serum testosterone and arterial blood gas values in men with chronic obstructive airways disease. 2. Depression of serum testosterone concentrations was found. 3. The degree of testosterone depression was related to the severity of arterial hypoxia.

Fibre-optic bronchoscopy is widely used to diagnose bronchial carcinoma. There is considerable variation in techniques for patient sedation, methods of obtaining samples and histopathological yield. We wished to examine variations in practice in different centres throughout Scotland and derive realistic audit standards for best clinical practice from these results. Diagnostic bronchoscopies from five centres were included. Patient details, grade of individual performing the test, endobronchial abnormalities, specimens taken and the histocytological yield were recorded. A patient satisfaction questionnaire was completed. One thousand eight hundred and two bronchoscopies were performed to look for bronchial carcinoma. Sedation and anaesthesia techniques varied considerably between centres. There were marked differences in patient satisfaction between centres. Nearly twice as many females as males would prefer not to have bronchoscopy repeated. Six hundred and fifty-eight carcinomas were confirmed by histocytology. Yield was unaffected by the grade of doctor performing bronchoscopy. Improving yield may be achieved by increasing the number of sampling techniques employed and changing the order in which specimens are taken (biopsies first and washings last). Eighty-seven percent of endoscopically visible tumours were confirmed histocytologically. There was a considerable variation in histological spectra between centres that may relate to differences in pathological interpretation rather than actual differences in case mix. Suggested audit standards are discussed. This study demonstrates the variety of techniques and also the levels of histocytological yield and patient satisfaction that can be achieved. Provisional standards of practice for this procedure have been agreed with a view to auditing performance against these. It is hoped that centres will adopt the methods that are shown to achieve the highest standards.

Eight men with hypoxia associated with idiopathic pulmonary fibrosis were studied. Serum testosterone concentrations were low in two subjects and fell to subnormal levels in two others as the clinical condition and arterial oxygen tension deteriorated. There was a significant correlation between serum testosterone concentrations and arterial oxygen tensions (p < 0.05). Three patients showed evidence of suppression of luteinising hormone secretion at the pituitary level. Only occasional abnormalities of thyroid and prolactin concentrations were noted. Most of the men suffered from organic sexual impotence, which is considered to be due at least in part to endocrine disturbance. These findings are similar to observations in patients with hypoxic chronic obstructive airways disease and support the hypothesis that hypoxia of lung disease suppresses the hypothalamo-pituitary-testicular axis. While studying metabolic aspects of chronic obstructive lung disease we found reduced serum testos-terone values in affected men' and were able to show an association between severity of hypoxia and degree of testosterone suppression.2 In subsequent studies we showed suppression of the hypothalamus or pituitary or both and not of the testes themselves to be responsible3 and other aspects of endocrine function to be comparatively normal. Such changes were reversible, improving with a rise in arterial oxygen tension in patients recovering from acute exacerbations with cor pulmonale.4 These hormone abnormalities had not previously been described in such patients, although low levels of urinary 17 ketosteroids had been noted at high altitude, indicating reduced testosterone production in the hypoxia of altitude,5 and also in emphysema.6 We have shown that organic sexual impotence can be a consequence of such low anabolic steroid production.' As there have been no reported studies of the hypothalamo-pituitary-testicular axis or sexual function in other clinical conditions characterised by hypoxia we set out to study a group of men with hypoxia secondary to pulmonary fibrosis. Methods Approval for the project was granted by the hospital ethical committee and informed written consent was obtained from all patients. Eight men attending a chest clinic who were considered to have radio-graphic evidence of pulmonary fibrosis were invited to participate. All had fine late inspiratory crackles and in no case was an aetiological factor incriminated. Severity of breathlessness was gauged with the help of the Medical Research Council questionnaire on respiratory symptoms8 and the six married patients under the age of 70 were asked questions relating to their sexual function. Lung function studies included measurement of FEV, and forced vital capacity (FVC), residual volume and total lung capacity (TLC) (helium dilution method), and single breath transfer factor (TLco). The results obtained were compared with predicted normal values.9 '0 Arterial blood samples for gas analysis were taken from the radial artery after the patient had been lying dow...