Influence of socioeconomic status on lung function and prediction equations in Indian children.

The present study was carried out to assess the influence of socioeconomic status on lung functions and to suggest prediction equations for Indian children. For this purpose, 2,616 normal, healthy schoolchildren aged between 5-15 years were recruited. Boys were classified into three groups, i.e., high-income (HIG), middle-income (MIG), and low-income (LIG), while girls were classified into HIG and LIG groups, based on socioeconomic status (SES). Height, weight, chest circumference, body surface area (BSA), fat-free mass (FFM), and body fat were assessed. Forced expiratory volume in 1 sec (FEV1), forced vital capacity (FVC), FEV1/FVC ratio, and peak expiratory flow rate (PEFR) were measured. The results, before and after adjustment of physical characteristics, showed that anthropometry, body composition, and lung functions were significantly higher in HIG compared to MIG and LIG children, while in girls, no differences were observed in physical characteristics after adjustments. Multiple linear regression equations were developed to predict FEV1, FVC, and PEFR, using independent variables like age, height, fat-free mass, and SES. It is opined that these equations could be used as Indian reference equations for healthy children based on the SES. Copyright 2005 Wiley-Liss, Inc.