Bone Mineral Density and Fat-Soluble Vitamin Status in Adults with Cystic Fibrosis Undergoing Lung Transplantation: A Pilot Study.

PURPOSE: Patients with cystic fibrosis (CF) often experience low bone mineral density (BMD) pre- and post-lung transplantation (LTX). The study purpose was to describe BMD and micronutrient status in adults with CF pre- and post-LTX. METHODS: Twelve patients with CF (29 ± 8 years) were recruited from the CF clinic at the University of Alberta Lung Transplant Program. BMD and vitamins A, D, E, K status, and parathyroid hormone were measured pre- and post-LTX. RESULTS: No significant differences pre- and post-LTX were observed at the different bone sites measured (lumber-spine, femoral-neck (FN), hip, and femoral-trochlea) (P > 0.05). BMD T-scores (<-2) was present in lumbar-spine, FN, hip, and femoral-trochlea in 33%, 17%, 17%, and 25% of individuals pre-LTX and 58%, 33%, 58%, and 33% of individuals post-LTX, respectively. More than 50% of patients had suboptimal vitamin K levels (PIVKA-II values >3 ng/mL) pre- and post-LTX. CONCLUSION: Adults with CF pre- and post-LTX had reduced BMD and suboptimal vitamin K status.

Newborn screening for cystic fibrosis in Alberta: Two years of experience.

On April 1, 2007, Alberta became the first province in Canada to introduce cystic fibrosis (CF) to its newborn screening program. The Alberta protocol involves a two-tier algorithm involving an immunoreactive trypsinogen measurement followed by molecular analysis using a CF panel for 39 mutations. Positive screens are followed up with sweat chloride testing and an assessment by a CF specialist. Of the 99,408 newborns screened in Alberta during the first two years of the program, 221 had a positive CF newborn screen. The program subsequently identified and initiated treatment in 31 newborns with CF. A relatively high frequency of the R117H mutation and the M1101K mutation was noted. The M1101K mutation is common in the Hutterite population. The presence of the R117H mutation has created both counselling and management dilemmas. The ability to offer CF transmembrane regulator full sequencing may help resolve diagnostic dilemmas. Counselling and management challenges are created when mutations are mild or of unknown clinical significance.

Effects of positive end-expiratory pressure on oscillated volume during high frequency chest compression in children with cystic fibrosis.

OBJECTIVE: To investigate the effects of positive end-expiratory pressure (PEEP) on end-expiratory lung volume (EELV) and mean oscillated volume (V(osc)) during high frequency chest compression (HFCC). DESIGN: A clinic-based prospective intervention study. SETTING: Pulmonary function laboratory, University of Alberta, Edmonton, Alberta. POPULATION: Nine children with cystic fibrosis with little or no obstructive airway disease who were selected from the outpatient Cystic Fibrosis and Pediatric Pulmonary Clinics at the University of Alberta Hospital, Edmonton, Alberta. METHODS: Each child received HFCC alone (at 10 Hz with chest wall pressure of 8 cm H2O) and HFCC plus PEEP. A closed circuit spirometry system was used to measure HFCC- and PEEP-induced changes in EELV, expressed as per cent baseline functional residual capacity (FRC) measured using helium dilution. An isothermic chamber permitted measurement of V(osc). RESULTS: HFCC caused a significant 9% decrease in EELV. Adding 2.0 +/- 0.3 cm H2O of PEEP increased EELV back to at least the FRC level. With HFCC alone, Vosc was significantly lower during spontaneous expiration than during spontaneous inspiration, but adding PEEP to HFCC increased V(osc), especially during spontaneous expiration. CONCLUSIONS: Adding PEEP during HFCC prevents the decrease in EELV and increases V(osc). Therefore, PEEP may improve HFCC-induced mucus clearance in children with cystic fibrosis.

Low bone mineral density in cystic fibrosis patients.

The goals of this practice-based, observational study were to describe the prevalence of low bone mineral density in patients at the Edmonton Cystic Fibrosis Centre, and to determine if body mass index and previous systemic corticosteroid use of over one month's duration were predictors of low bone mineral density. One hundred and thirteen pediatric and adult patients were studied. Bone mineral density of the lumbar spine region was measured using dual-energy X-ray absorptiometry. A total of 42.5% of patients had a bone mineral density Z-score of less than -1 standard deviation. Low bone mineral density was apparent at nine to 12 years of age, and was most evident in the 20- to 34-year-old group. All but one patient under age 20 with a Z-score of less than -2.5 also had a body mass index below the fifth percentile. A low Z-score was also associated with previous systemic corticosteroid use of over one month's duration (relative risk 1.81, p=0.003). We conclude that low bone mineral density is common in cystic fibrosis patients. Low body mass index percentiles may be used to identify children and adolescents at risk of low bone mineral density. These patients may benefit from aggressive nutrition therapy. Systemic corticosteroid use should be assessed carefully, as it is a risk factor for low bone mineral density.