Sunday, March 14, 2010

Grow Taller with Wheezing?

Here's a fascinating theory that I uncovered about a novel height increase method:

Inhaled Glucocorticoids and Adult Height

"in principle, children could become shorter adults because of [glucocorticoid] therapy or they could become taller because of continued wheezing. Height depends on shape as well as bone length. At rest, breathing is normally relaxed, with little movement of the thorax, back, and neck. Expiratory obstruction leads to more forceful breathing, with rising of the thorax and straightening of the vertebral column during inspiration [inhalation]. Thus wheezing could lead to a raised thorax and straightened back. If, at the time of vertebral maturation, this increase in length became embodied, a difference in height between children with wheezing and treated children with asthma might persist unchanged until adulthood, as Kelly et al. found. If so, the average arm or leg length in adults should be the same in both groups, and it would be interesting to know whether this is so. In addition, in the adults, it would be of value to know the degree of lordosis according to treatment group."

Rebuttal:

"We thank Hughes-Davies for his intriguing hypothesis that ongoing airway obstruction might result in greater apparent growth in the children who received placebo and nedocromil as compared with the children who received inhaled glucocorticoids in our study. We are unaware of data supporting his hypothesis. However, there is evidence that uncontrolled asthma can result in growth reduction; these data counter the possibility that height is increased in uncontrolled asthma. The one study assessing the effect of asthma on posture, including straightness of backs in children, showed no effect, and we used standard techniques for measuring height, including instructions on posture and body alignment. We also observed that a longer duration of asthma before randomization was an independent risk factor for decreased, not increased, adult height. Since arm span and knee height were not obtained in our population, we cannot determine whether they were disproportionately affected as compared with height. The small effect of inhaled glucocorticoids on adult height must be balanced against their well-established benefits in controlling persistent asthma"

Effect of Inhaled Glucocorticoids in Childhood on Adult Height

"the use of inhaled glucocorticoids has been shown to reduce growth velocity, resulting in a linear growth reduction of 0.5 to 3.0 cm (approximately 1 cm on average) during the first few years of therapy."

"In one small longitudinal study [for inhaled glucocorticoids to treat asthma], there was no significant difference between actual adult height and predicted adult height in 142 participants who had received budesonide in variable daily doses (mean, 427 μg) during childhood for a mean of 9.2 years."  The lack of impact on adult height may be due to catch up growth.

"we compared the efficacy and safety of 200 μg of budesonide administered by means of a dry-powder inhaler twice daily (400 μg per day), 8 mg of nedocromil administered by means of a metered-dose inhaler twice daily (16 mg per day), and placebo."

"The adjusted mean adult height was 1.2 cm lower in the budesonide group than in the placebo group (171.1 cm vs. 172.3 cm); the mean adult height in the nedocromil group (172.1 cm) was similar to that in the placebo group"

" the height deficit observed at 1 to 2 years after treatment initiation persisted into adulthood, although the deficit was neither progressive nor cumulative."

Asthma has been shown to independently inhibit linear growth.

The study that analyzed Asthma and posture:

 Analysis of body posture in children with mild to moderate asthma

" The mechanical alterations related to the excessive use of accessory respiratory muscles and the mouth breathing observed in children with asthma may lead to the development of alterations in head posture, shoulders, thoracic region and, consequently, in alterations of body posture. The purpose of this study was to assess body posture changes of children with asthma compared to a non-asthmatic control group matched for gender, age, weight, and height. Thirty children with asthma and 30 non-asthmatic children aged 7 to 12 years were enrolled in this study. Digital photographic records were obtained for analysis of the body posture of the children by computed photogrammetry. No significant differences between groups for the angles analyzed, except for the knee flexor angle. Children with asthma did not present postural alterations compared to non-asthmatic controls since the only angle for which there was a significant difference between groups showed weak reproducibility. Children with asthma [do not] present alterations in body posture. "

"Children with asthma also might present decreased thoracic mobility, shortening of the pectoral muscles, elevated and adducted shoulders, winged scapulae, increased kyphosis, shortening of the neck musculature, and shortening of the hip and knee flexor musculature."

"body posture changes in children with asthma could be caused mainly by hyperinflation leading to flattening of the diaphragm muscle and to the consequent use of accessory cervical muscles"

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