Relation between fat mass, fat free mass and ventilatory function in children and adolescents / 生理学报

ABSTRACT

The aim of the present study was to evaluate the relation between fat mass (FM), fat free mass (FFM) and ventilatory function in children and adolescents. 1 174 healthy children and adolescents (583 males and 591 females) aged 10-18 years were selected from Heilongjiang Province through random sampling by means of questionnaire and physical examination, and measured for height, weight, waist to hip ratio (WHR), FM, FFM and ventilatory function. The data were analyzed by means of independent-samples t test, Pearson correlation analysis and multi-factors regression analysis. Regardless of sex, an independent positive correlation was found (P<0.001) between age and FFM index (FFMI). FM index (FMI) correlated negatively with age in males (P<0.001), but positively with age in females (P<0.001). Regardless of sex, FFMI correlated positively with forced vital capacity (FVC), forced expiratory volume in one second (FEV1), peak expiratory flow (PEF), forced expiratory flow at 25% of forced vital capacity (FEF25%), FEF50%, and maximal mid-expiratory flow (MMEF) (P<0.05), while negatively with FEV1/FVC (P<0.01). FFMI was correlated positively with FEF75% in males (P<0.05), but not correlated in females. In males, FMI correlated negatively with FEV1, FEV1/FVC, PEF, FEF25%, FEF50%, FEF75% and MMEF (P<0.05), but not correlated with FVC. No correlation was found between the ventilatory function indices and FMI in females. Except FEV1/FVC and FEF75% in males, the effect of FFMI in predicting ventilatory function was higher than FMI regardless of sex. Moreover, the predicting effect of FFMI was higher in males than that in females. Growth spurt of lung function occurred in the ages of 12-15 years in males, while in the ages of 12, 13 and 18 years in females. During the period of growth spurt of lung function, regardless of sex, the effect of FFMI in predicting the lung function was higher than that of age. In conclusion, regardless of sex, FFMI correlates positively with ventilatory function, as a reflection of muscle mass. The effect of FFM in predicting ventilatory function is higher in males than that in females. FM correlates negatively with ventilatory function in males, but not in females. The rapid growth of height and FFM are possibly the main reasons for growth spurt of lung function.