Forced vital capacity (FVC), forced expiratory volume in one second (FEV1), peak expiratory flow rate (PEFR), single-breath diffusion capacity measurements (effective alveolar volume (VA), carbon monoxide transfer factor (DLCO) and transfer coefficient (KCO)) were determined in 452 healthy Singaporean adults (277 males and 175 females) aged 20-70 years. The ratio of Chinese, Malay and Indian subjects was 5:2:3 in both sexes. Age, height and weight in the males were all significantly correlated with FEV1, FVC, DLCO, VA and PEFR. However, for females, only age and height were significantly correlated with the studied lung function parameters. Significant ethnic differences were observed for most of the pulmonary functions (except KCO and PEFR) among the Chinese, Malays and Indians for both males and females. The predicted FEV1 and FVC values (specific age and height) for both sexes were highest among the Chinese followed by the Malays than Indians, in that order. Regression equations, with age and height as independent variables, were derived for males and females in each ethnic group to predict normal pulmonary function for the Singapore Chinese, Malay and Indian populations. The predicted values of various pulmonary function measurements obtained from these regression equations for subjects of specified age (30 years) and height (165 cm for men, 155 cm for women) were compared with those reported in other studies. Differences were observed among the different races.
The aim of this study was to: (1) determine the prevalence and patterns of lung dysfunction among transfusion dependent thalassemics; (2) determine the associated factors that might contribute to this problem. This was a cross-sectional study involving 66 patients with transfusion dependent thalassemia aged 10 years and above. All patients underwent physical examination, standardized pulmonary function tests including spirometry, lung volume, and the carbon monoxide diffusion capacity. A restrictive pattern of lung dysfunction was observed in 22 patients (33.3%) and none showed the presence of obstructive ventilatory impairment. A reduction in the carbon monoxide diffusion capacity (DLCO) was seen 87.9% of the patients, including 7.6% who had evidence of hypoxemia. Ten patients showed a reduction in the FEF25-75% although they did not fulfil the criteria for small airway disease. No correlation was found between lung dysfunction and serum ferritin levels in the patients. Restrictive lung dysfunction and diffusion impairment were the predominant abnormalities found in our cohort of patients.
Study site: Thalassemia clinic, Pusat Perubatan Universiti Kebangsaan Malaysia (PPUKM), Kuala Lumpur, Malaysia