Prediction formulae for lung function parameters in females of south eastern Nigeria

This study was carried out to obtain normal lung function values for women in south eastern Nigeria with a view to establishing prediction equations for forced vital capacity (FVC), forced expiratory volume at the first second (FEV(1)) and peak expiratory flow rate (PEFR). Lung function values were measured in 600 apparently healthy Nigerian women aged between 18 and 57 years. FVC and FEV1 were significantly related to height [P < 0.001] and [P < 0.01] respectively) and body weight [P < 0.01], PEFR was also related to age [P < 0.01] and height [P < 0.001]. Prediction equations for the various lung function indices were as follows: FVC = 0.145 + (1.390Ht) - (0.0076age) + (0.0089wt); FEV1 = 0.240 + (1.045Ht) - (0.0055age) + (0.0064wt); PEFR = -38.80 + (210.83Ht) + (1.650age) + (0.252wt). Ht is height in meters, wt. is body weight in kilograms and age is age in years. The ventilatory function indices were directly proportional to weight, height and to age. All the observed or measured lung function indices were not significantly different from their predicted values using the above prediction equations. Therefore, we conclude that lung function indices are influenced by the anthropometric parameters viz: age, body weight and height, and the prediction equations stated for FVC, FEV1 and PEFR for Nigerian women between the ages 18 and 57 years are reliable.