Pulmonary Vascular Physiology and Exercise Tolerance in Adults with Sickle Cell Disease During Steady State in Ibadan, Oyo State

Pulmonary vascular changes in sickle cell disease contribute to reduced exercise tolerance, yet haemodynamic and cardiopulmonary exercise testing data from Nigerian sickle cell populations are conspicuously absent from current literature. This study examined pulmonary vascular physiological indices and exercise tolerance in adults with sickle cell disease in steady state at a specialist clinic in Ibadan, Oyo State, South West Nigeria. A cross-sectional comparative design enrolled 60 adults with confirmed sickle cell disease and 30 age-matched healthy haemoglobin AA controls. Echocardiographic assessment estimated pulmonary artery systolic pressure. Cardiopulmonary exercise testing measured peak oxygen consumption, ventilatory threshold, and minute ventilation to carbon dioxide output ratio. Six-minute walk distance was also recorded. Multiple regression, ANOVA, and chi-square were applied. Results showed significantly elevated estimated pulmonary artery systolic pressure in sickle cell disease patients, with 28.3 percent meeting echocardiographic criteria for pulmonary hypertension. Peak oxygen consumption and six-minute walk distance were significantly lower in patients than controls. Pulmonary artery pressure was the strongest independent predictor of exercise capacity. Haemoglobin level also contributed independently. This study provides the first cardiopulmonary exercise characterisation of sickle cell disease in a Nigerian outpatient population, filling a critical evidence gap. Pulmonary hypertension screening and graded exercise rehabilitation are recommended. Keywords: sickle cell disease, pulmonary hypertension, exercise tolerance, cardiopulmonary, Ibadan.