Relationship between estimated body fat and some respiratory function indices

To find the relationship between estimated body fat and respiratory function indices.

Cross sectional study of volunteers in the physiotherapy department.

Physiotherapy patients with no respiratory or neuromascular diseases.

Quetelet index (as measure of body fat), vital capacity and breath holding time.

Their ages ranged from 20 year to 60 years with a mean 24.20 +/- 6.59 years and 29.72 +/- 14.18 years in males and females respectively. Subjects whose quetelet index was about 30 kg/m2 and above were classified as obese. None of the male subjects fell into the obese category, while six of the 50 female subjects fell into the obese category. Significant differences were observed in the mean of the Quetelet index, percent predicted vital capacity and the breath holding time between the normal female and the obese female subjects. A high but inverse relationship was found between estimated body fat and each percent predicted vital capacity and breath holding time in subjects whose Quetelet index was above 30 kg/m2. There was also a high and positive correlation between percent predicted vital capacity and breath holding time in subjects with Quetelet index above 30 kg/m2.

These findings were attributed to the restrictive effect of excess adipose tissue located around the thorax and the abdomen. It was concluded that adequate caution should be taken during exercise therapy for patients with a Quetelet index value above 30 kg/m2 to enable them exercise safely and with respiratory efficiency.