Waist circumference, BMI, and lung function in 8-year-old children: the PIAMA birth cohort study.

BACKGROUND

Body mass index (BMI) and waist circumference (WC) may be associated with lung function in children, as observed in adults.

METHODS

Height, weight, waist circumference, and lung function (FVC and FEV1 ) were measured during a medical examination in 1,058 eight-year-old children participating in the Prevention and Incidence of Asthma and Mite Allergy (PIAMA) birth cohort study.

RESULTS

After adjusting for height, age and other potential confounders large WC or high BMI (>90th percentile) were not associated with forced expiratory volume in 1 sec (FEV1) or forced vital capacity (FVC). In girls only, large WC was, independently of BMI, associated with 3.5% (95% confidence interval (CI): -6.4, -0.6) lower FEV1 /FVC ratio in the model including WC and BMI. Girls with low BMI (<10th percentile) had 4.6% lower FEV1 (95% CI: -8.4, -0.6) and 5.1% lower FVC (95% CI: -8.8, -1.2) than girls with normal BMI. In boys, we did not observe associations between low or high BMI and lung function independent of WC, or between small or large WC and lung function after adjustment for BMI.

CONCLUSION

At 8 years of age, a high BMI or large WC are not yet associated with FEV1 and FVC, indicating that this association may change over the course of life from childhood to adulthood.