Low stature but high spirometric values

EDITORIAL

Low stature but high spirometric values

Noé Zamel

Medicine Professor, Toronto University, Toronto, Canada

Spirometry and flow-volume curve are the most widely used respiratory tests in clinical practice. Although the flow-volume curve is more discriminating, spirometry is still the most widely used test for both diagnosis and treatment follow-up, as well as in epidemiological studies.

Spirometry reference values are related to gender, age, height, and race. Caucasian subjects have approximately 10% higher values than subjects from other ethnic origins, including Afro-Americans and Asians. The reference values determined for a generation are not necessarily valid for other generations. Thus, spirometry reference values have a life span of 20 years.

Subjects used to determine spirometry reference values are non-smokers and have good general and, specially, respiratory health. In growing children, spirometry reference values increase with age and height. In adults, these parameters become lower with increasing age. There is a transitory phase between childhood and adulthood for which there are very few reference values, and therefore, reference values for adolescents are generally extrapolated, based on children’s or adults’ values, which may result in estimation errors for the predicted reference values for this age range, specially between 16 to 18 years.

The study by Dorneles et al, published at this issue of Jornal de Pneumologia⁽¹⁾, is about reference values for low stature children and adolescents who don’t have any respiratory problems. The authors conclude that historical reference values are approximately 10% lower than the observed spirometric parameters for this population. North-American subjects’ values were used for comparison ⁽²⁾, which is not considered an issue, since they are not significantly different from Brazilian subject’s values ⁽³⁾. Dorneles et al suggest that the estimated stature for percentile 50, for a given bone age, should be used on pulmonary function assessment.

References

1. Dorneles NA, Rosário Filho NA, Riedi CA, Boguszewski MC, Barros JA. Valores espirométricos de crianças e adolescentes com baixa estatura. J Pneumol 2003;

2. Polgar C, Promadhat V. Standard values. In: Pulmonary function testing in children: techniques and standards.1^st ed. Philadelphia: WB Saunders, 1971;87-122.

3. Rodrigues JC, Cardieri JMA, Bussamra MHCF, Nakaie CMA, Almeida MB, Silva Filho LVF, et al. Provas de função pulmonar em crianças e adolescentes. J Pneumol 2002;28(Supl 3):207-21.

Publication Dates

• Publication in this collection
  02 Dec 2003
• Date of issue
  Aug 2003