ABSTRACT
AIM: The study is designed to probe for the relationship between waist to hip ratio(WHR)and static lung volumes of adults. METHODS: In July-October 2008, 1 307 healthy adults(372 males and 935 females)were selected in Heilongjiang province by means of questionnaire and physical examination. The height, weight, WHR, fat mass, percentage body fat and lung function were measured, and then grouped according to the standard of classification of WHR(central obesity male WHR ≥ 0.86, female ≥ 0.82)for analysis of the relationship between WHR and static lung volume. RESULTS: WHR was found, regardless of sex, to tend to go up with the increase in age and BMI(P<0.01), and both the fat mass and percentage body fat of the central obesity group were higher than those in the group with normal WHR(P<0.01). An independent negative correlation was found(P<0.05), also regardless of sex, between the WHR with expiratory reserve volume(ERV)in all these adults. ERV in central obesity group was lower than that in the group with normal WHR(P<0.05). Compared to the normal group, ERV in the central obesity group decreased by 11% for males and 8% for females(P<0.05). However, with regard to the relationship between WHR and VT, IC, MV, and VC, gender differences were found. For the males, a significant independent positive correlation was observed between WHR and IC(P<0.05), with IC of the central obesity group 6% higher than that in the group with normal WHR(P<0.05). For the females, significant independent positive correlation was found between WHR and MV(P<0.05), with the VT and MV of the central obesity group 7% and 6% higher(P<0.05), respectively, than that in the group with normal WHR. CONCLUSION: WHR is in an independent negative correlation with ERV. The elevation of WHR may play a role in the impairment of respiratory function. Its occurrence is accompanied by a rise of IC for the male and a rise of MV for the female. These changes in the two genders could be associated with the decrease in arterial oxygen tension caused by the decrease of ERV.
ABSTRACT
A study was conducted to clarify the influence of water immersion at different levels on pulmonary response. The subjects, ten healthy men (mean age, 26.2±7.9 years), subjected to measurement of static lung volumes and maximum expiratory flow-volume curves while sitting immersed in water at the level of both the neck and diaphragm. TLC, VC, ERV and FRC for water immersion at the diaphragm level were significantly decreased in comparison with those measured in air. These lung volumes were further decreased upon water immersion to neck level. However, RV did not change significantly upon immersion at either water level. Significant decreases of FEV<SUB>1⋅0</SUB>, FEV<SUB>1⋅0</SUB>%, V<SUB>50</SUB> and V<SUB>25</SUB> were observed upon water immersion at the diaphragm level as compared with those obtained in air. Water immersion to neck level produced further decreases in pulmonary functional parameters. Although peak flow and V<SUB>75</SUB> did not change significantly upon water immersion at either level, V<SUB>50</SUB> and V<SUB>25</SUB> were decreased markedly in comparison with the values obtained in air. A tendency for a marked decrease in pulmonary function parameters was observed upon water immersion to neck level. The changes observed upon water immersion to diaphragm level may have resulted from compression of small airways induced by both an increase of blood volume in the thorax and hydrostatic pressure against the abdomen. The changes induced by water immersion to neck level may have been exacerbated by the two mechanisms described above, in addition to hydrostatic pressure on the chest wall. The present results suggest that the significant reduction of pulmonary functional parameters caused by water immersion may be due to compression of small airways induced by an increase of blood volume in the thorax and hydrostatic pressure on the chest wall and abdomen.