RESUMEN
Vertebral deformities are prevalent in chronic obstructive pulmonary disease (COPD) patients and may cause excessive loss of height. As height is used for calculating reference values for pulmonary function tests, larger than normal height reduction could cause overestimation of lung function. In this cross-sectional study of 465 COPD patients and 462 controls, we explored how often lung function is misinterpreted due to height reduction in COPD patients, and whether the number or severity of vertebral deformities correlate with height reduction. Measured height was compared to recalled tallest height (RTH) and height calculated from arm span (ASH) to assess height reduction. Vertebral deformities were assessed from radiographs and pulmonary function was assessed using standard formulae. Height reduction was frequent in both the study and control groups, and increased with the number and severity of vertebral deformities. When using current measured height, lung function was overestimated in a significant proportion of COPD patients at relatively modest height reductions. The effects were smallest for forced expiratory volume in 1 s and forced vital capacity, and most pronounced for total lung capacity and residual volume. Therefore, we propose that in COPD patients with excessive height reduction, one might use RTH or ASH in calculating predicted values. Furthermore, such patients should be evaluated for co-existing vertebral deformities and osteoporosis.
Asunto(s)
Osteoporosis/complicaciones , Enfermedad Pulmonar Obstructiva Crónica/terapia , Anciano , Anciano de 80 o más Años , Estatura , Estudios Transversales , Femenino , Humanos , Pulmón/fisiopatología , Masculino , Persona de Mediana Edad , Noruega , Enfermedad Pulmonar Obstructiva Crónica/complicaciones , Enfermedad Pulmonar Obstructiva Crónica/patología , Valores de Referencia , Pruebas de Función Respiratoria , Fenómenos Fisiológicos RespiratoriosRESUMEN
Bone mineral density decreases with advancing chronic obstructive pulmonary disease (COPD) severity, but it is not known whether this is reflected in higher fracture rates. The present authors wanted to compare the prevalence of vertebral deformities in COPD patients with those in a population-based reference group to determine whether the number of deformities was related to the severity of COPD and how far the use of oral corticosteroids (OCS) influenced the prevalence of deformities. In the present cross-sectional study of 465 COPD patients and 462 controls, vertebral deformities were found in 31% of the COPD patients and 18% of the controls. In subjects who had never or sporadically used OCS, deformities were found in 29% of the COPD patients and 17% of the controls. In females, the average number of vertebral deformities was almost two-fold when COPD severity increased from Global Initiative of Chronic Obstructive Lung Disease stage II to III. In males, the use of OCS had a small but significant influence. Prevalence of vertebral deformities was significantly higher in chronic obstructive pulmonary disease patients than in the controls. In females, the average number of deformities was related to chronic obstructive pulmonary disease severity even after adjustment for other known risk factors. The difference between patients and controls remained significant even in those who never or sporadically used oral corticosteroids.
Asunto(s)
Enfermedad Pulmonar Obstructiva Crónica/complicaciones , Columna Vertebral/anomalías , Administración Oral , Corticoesteroides/administración & dosificación , Anciano , Anciano de 80 o más Años , Densidad Ósea , Estudios de Casos y Controles , Distribución de Chi-Cuadrado , Femenino , Humanos , Masculino , Persona de Mediana Edad , Distribución de Poisson , Prevalencia , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Radiografía , Pruebas de Función Respiratoria , Factores de Riesgo , Índice de Severidad de la Enfermedad , Columna Vertebral/diagnóstico por imagen , Columna Vertebral/fisiopatologíaRESUMEN
Chronic obstructive pulmonary disease (COPD) appears to be associated with low bone mineral density (BMD). BMD loss can be accelerated by a number of factors associated with COPD, but it is not known whether COPD itself has a direct effect. Our aim was to investigate in a cross-sectional study whether COPD patients have lower BMD than healthy individuals, and whether the severity of the disease affects BMD. Eighty-eight COPD patients attending a rehabilitation program were classified into stages II, III and IV using GOLD criteria. BMD was measured by dual X-ray absorptiometry in lumbar spine (L2-4), femoral neck (FN) and total body (TB). Values were converted to Z-scores (adjusted for age and sex). Associations between Z-scores and steroid use, body mass index, pack-years and six-min walking distance were analyzed. The Z-scores (mean and (CI)) for all patients were for L2-4: -0.6 (-0.9, -0.3), FN: -0.8 (-1.0, -0.5) and TB: -0.5 (-0.8, -0.2). All scores were significantly different from those of a control population (p<0.001). For all three variables (ZL2-4, ZFN, ZTB) there were significant differences between the stages. The difference for ZL2-4 was still significant after adjustment for risk factors. We conclude that BMD is low in COPD patients and decreases with increasing severity of the disease. Low BMD may to some extent be a disease-specific effect.