Objective: To study the effect of obesity on pulmonary function in newly diagnosed asthmatic children of different age groups.
Methods: Two hundred and ninety-four children with newly diagnosed asthma were classified into preschool-age (<6 years) and school-age (6 to 12.5 years) groups. They were then classified into obese, overweight, and normal-weight subgroups based on their body mass index (BMI). All the children underwent pulmonary function tests, including large airway function tests [forced vital capacity (FVC%) and forced expiratory volume in one second (FEV1%)] and small airway function tests [maximal expiratory flow at 25% of vital capacity (MEF25%), maximal expiratory flow at 50% of vital capacity (MEF50%), and maximal expiratory flow at 75% of vital capacity (MEF75%)].
Results: The school-age group showed lower FEV1%, MEF25%, and MEF50% than the preschool-age group (P<0.05) after adjustment for sex and BMI. The normal-weight children in the school-age group had lower FEV1%, MEF25%, and MEF50% compared with their counterparts in the preschool-age group (P<0.05). The overweight children in the school-age group showed lower FVC% and MEF50% than those in the preschool-age group. However, all the pulmonary function parameters showed no significant differences between the obese children in the preschool-age and school-age groups. In the preschool-age group, FVC%, FEV1%, and MEF75% of the obese children were lower than those of the normal-weight children. In the school-age group, only FVC% and FEV1% showed differences between the obese and normal-weight children (P<0.05).
Conclusions: The effect of obesity on the pulmonary function varies with age in children with asthma, and the effect is more obvious in those of preschool age.
目的: 研究肥胖对不同年龄段初诊哮喘患儿肺功能的影响。
方法: 294名初诊哮喘患儿按年龄分为学龄前期组（ < 6岁）及学龄期组（6~12.5岁），并根据不同体重指数（BMI）分为体重正常哮喘组、超重哮喘组及肥胖哮喘组，检测患儿肺功能，包括大气道通气功能指标[用力肺活量（FVC）、第1秒用力呼气量（FEV1）]和小气道通气功能指标[用力呼气25%、50%及75%流量的实测值占预计值的百分比，即MEF25%、MEF50%、MEF75%]。
结果: 在校正了性别及BMI分组因素后，学龄期组FEV1%、MEF25%、MEF50%低于学龄前期组（P < 0.05）。两年龄组正常体重患儿间比较，学龄期组基础肺功能FEV1%、MEF25%、MEF50%低于学龄前期组（P < 0.05）；两年龄组超重患儿间比较，学龄期组FVC%及MEF50%低于学龄前期组；两年龄组肥胖患儿间比较，肺功能各指标差异均无统计学意义。学龄前期肥胖组FVC%、FEV1%及MEF75%均低于体重正常组，而学龄期肥胖组仅FVC%和FEV1%与体重正常组间差异有统计学意义（P < 0.05）。
结论: 肥胖对哮喘患儿基础肺功能的影响存在年龄差异，于学龄前期更明显。