Evaluation of bone disease in patients with cystic fibrosis and end-stage lung disease.

OBJECTIVE: Bone disease is a common comorbidity in patients with cystic fibrosis (CF). We sought to determine risk factors and identify potential biochemical markers for CF-related bone disease (CFBD) in a unique cohort of CF patients with end-stage lung disease undergoing lung transplantation (LTx) evaluation. METHODS: All of the CF patients who were evaluated for LTx at our center between November of 1992 and December of 2010 were included in the study. Clinical data and biochemical markers of bone turnover, as well as bone mineral density (BMD) at the lumbar spine and femoral neck, were evaluated. Spearman's rho and multivariate logistic regression analysis were used. RESULTS: A total of 102 adult CF patients were evaluated. The mean age was 28.1 years (95% CI: 26.7-29.5), and the mean body mass index was 17.5 kg/m2 (95% CI: 17.2-18.2). Mean T-scores were -2.3 and -1.9 at the lumbar spine and femoral neck, respectively, being lower in males than in females (-2.7 vs. -2.0 at the lumbar spine and -2.2 vs. -1.7 at the femoral neck). Overall, 52% had a T-score of < -2.5 at either skeletal site. The homozygous Phe508del genotype was found in 57% of patients without osteoporosis and in 60% of those with low BMD. Mean T-scores were not particularly low in patients with severe CFTR mutations. Although the BMI correlated with T-scores at the femoral neck and lumbar spine, serum 25-hydroxyvitamin D and parathyroid hormone levels did not. CONCLUSIONS: CFBD is common in CF patients with end-stage lung disease, particularly in males and patients with a low BMI. It appears that CF mutation status does not correlate with CFBD. In addition, it appears that low BMD does not correlate with other risk factors or biochemical parameters. The prevalence of CFBD appears to have recently decreased, most likely reflecting increased efforts at earlier diagnosis and treatment.

Evaluation of bone disease in patients with cystic fibrosis and end-stage lung disease / Avaliação de doença óssea em pacientes com fibrose cística e doença pulmonar terminal

ABSTRACT Objective: Bone disease is a common comorbidity in patients with cystic fibrosis (CF). We sought to determine risk factors and identify potential biochemical markers for CF-related bone disease (CFBD) in a unique cohort of CF patients with end-stage lung disease undergoing lung transplantation (LTx) evaluation. Methods: All of the CF patients who were evaluated for LTx at our center between November of 1992 and December of 2010 were included in the study. Clinical data and biochemical markers of bone turnover, as well as bone mineral density (BMD) at the lumbar spine and femoral neck, were evaluated. Spearman's rho and multivariate logistic regression analysis were used. Results: A total of 102 adult CF patients were evaluated. The mean age was 28.1 years (95% CI: 26.7-29.5), and the mean body mass index was 17.5 kg/m2 (95% CI: 17.2-18.2). Mean T-scores were −2.3 and −1.9 at the lumbar spine and femoral neck, respectively, being lower in males than in females (−2.7 vs. −2.0 at the lumbar spine and −2.2 vs. −1.7 at the femoral neck). Overall, 52% had a T-score of < −2.5 at either skeletal site. The homozygous Phe508del genotype was found in 57% of patients without osteoporosis and in 60% of those with low BMD. Mean T-scores were not particularly low in patients with severe CFTR mutations. Although the BMI correlated with T-scores at the femoral neck and lumbar spine, serum 25-hydroxyvitamin D and parathyroid hormone levels did not. Conclusions: CFBD is common in CF patients with end-stage lung disease, particularly in males and patients with a low BMI. It appears that CF mutation status does not correlate with CFBD. In addition, it appears that low BMD does not correlate with other risk factors or biochemical parameters. The prevalence of CFBD appears to have recently decreased, most likely reflecting increased efforts at earlier diagnosis and treatment.

RESUMO Objetivo: A doença óssea é uma comorbidade comum em pacientes com fibrose cística (FC). Nosso objetivo foi determinar os fatores de risco e identificar possíveis marcadores bioquímicos de doença óssea relacionada à FC (DOFC) em uma coorte única de pacientes com FC e doença pulmonar terminal submetidos a avaliação para transplante de pulmão (TxP). Métodos: Todos os pacientes com FC avaliados para TxP em nosso centro entre novembro de 1992 e dezembro de 2010 foram incluídos no estudo. Foram avaliados dados clínicos e marcadores bioquímicos de remodelação óssea, bem como a densidade mineral óssea (DMO) na coluna lombar e colo do fêmur. Foram usados rô de Spearman e análise de regressão logística multivariada. Resultados: Foram avaliados 102 pacientes adultos com FC. A média de idade foi de 28,1 anos (IC95%: 26,7-29,5), e a média do índice de massa corporal foi de 17,5 kg/m2 (IC95%: 17,2-18,2). A média do escore T foi de −2,3 e −1,9 na coluna lombar e colo do fêmur, respectivamente, sendo menor nos homens que nas mulheres (−2,7 vs. −2,0 na coluna lombar e −2,2 vs. −1,7 no colo do fêmur). No geral, 52% apresentaram escore T < −2,5 em um dos dois sítios esqueléticos. O genótipo homozigoto para Phe508del foi encontrado em 57% dos pacientes sem osteoporose e em 60% daqueles com DMO baixa. A média do escore T não foi particularmente baixa em pacientes com mutações graves do gene CFTR. Embora o IMC tenha se correlacionado com o escore T no colo do fêmur e coluna lombar, os níveis séricos de 25-hidroxivitamina D e paratormônio não o fizeram. Conclusões: A DOFC é comum em pacientes com FC e doença pulmonar terminal, particularmente em homens e pacientes com IMC baixo. O estado de mutação da FC aparentemente não se correlaciona com a DOFC. Além disso, aparentemente não há correlação entre DMO baixa e outros fatores de risco ou parâmetros bioquímicos. A prevalência de DOFC parece ter diminuído recentemente, o que provavelmente é reflexo do aumento dos esforços para antecipar o diagnóstico e tratamento.