Young adults with cystic fibrosis are shorter than healthy peers because their parents are also short

An overview of international literature from cystic fibrosis registries. Part 4: update 2011

A total of 53 national cystic fibrosis (CF) patient registry studies published between July 2008 and November 2011 have been reviewed, focusing on the following topics: CF epidemiology, nutrition, microbiology, clinical complications, factors influencing diagnosis and lung disease, effects of socioeconomic status, therapeutic strategy evaluation, clinical trial methodology. The studies describe the clinical characteristics of CF patients, the incidence and prevalence of disease and role of gender gap, as well as the influence of socioeconomic status and environmental factors on clinical outcomes, covering a variety of countries and ethnic groups. Original observations describe patients as they get older, with special reference to the adult presentation of CF and long-term survival. Methodological aspects are discussed, covering the design of clinical trials, survival analysis, auxometry, measures of quality of life, follow up of lung disease, predictability of disease progression and life expectancy. Microbiology studies have investigated the role of selected pathogens, such as Burkholderia species and MRSA. Pulmonary exacerbations are discussed both as a factor influencing morbidity and an endpoint in clinical trials. Finally, some studies give insights on complications, such as CF-related diabetes and hemoptysis, and emerging problems, such as chronic nephropathy.

Incorporating genetic potential when evaluating stature in children with cystic fibrosis

OBJECTIVE

The 2002 Cystic Fibrosis Foundation (CFF) practice guidelines recommend adjusting for genetic potential when evaluating height status in children with CF. However, there is paucity of data to support this recommendation. We compared three methods of classifying short stature: unadjusted height percentile <10th, Himes adjusted height percentile <10th, and unadjusted height below the CFF target height lower bound.

PATIENTS AND METHODS

Data from 3306 children with parental heights documented in the 1986-2005 CFF Patient Registry were analyzed.

RESULTS

Mean height percentile of CF children (33rd) was lower than their parents' (mothers' 53rd, fathers' 57th), and 80% of CF children were below the average of their parental height percentiles. In children with short parents, Himes adjusted height percentile was significantly higher than unadjusted height percentile (27th vs. 8th), whereas the opposite was found in children with tall parents (Himes adjusted at 18th vs. unadjusted at 49th). Consequently, the prevalence of short stature decreased from 52% to 22% in children with short parents and increased from 8% to 34% in children with tall parents after Himes adjustment. In children with discrepant classification on short stature before and after Himes adjustment, percent predicted forced expiratory volume in one second was negatively associated with unadjusted height percentile but positively associated with Himes adjusted height percentile. In children with short parents, the CFF method underestimated the prevalence of short stature (9%) compared to the Himes method (22%).

CONCLUSION

Without adjustment of genetic potential, the prevalence of short stature is underestimated and the association between height and lung function is biased.