RESUMO
Liver cirrhosis leads to bone loss. To date, information on bone quality (three-dimensional microarchitecture) and, thus, bone strength is scarce. We observed decreased bone quality at both assessed sites, independent of disease severity. Therefore, all patients should undergo early-stage screening for osteoporosis. INTRODUCTION: Recent studies found low bone mineral density in cirrhosis, but data on bone microstructure are scarce. This study assessed weight-bearing and non-weight-bearing bones in patients with cirrhosis and healthy controls. The primary objective was to evaluate trabecular and cortical microarchitecture. METHODS: This was a single-center study in patients with recently diagnosed hepatic cirrhosis. Thirty-two patients and 32 controls participated in this study. After determining the type of cirrhosis, the parameters of bone microarchitecture were assessed by high-resolution peripheral quantitative computed tomography. RESULTS: Both cortical and trabecular microarchitectures showed significant alterations. At the radius, trabecular bone volume fraction was 17% lower (corrected p = 0.028), and, at the tibia, differences were slightly more pronounced. Trabecular bone volume fraction was 19% lower (p = 0.024), cortical bone mineral density 7% (p = 0.007), and cortical thickness 28% (p = 0.001), while cortical porosity was 32% higher (p = 0.023), compared to controls. Areal bone mineral density was lower (lumbar spine - 13%, total hip - 11%, total body - 9%, radius - 17%, and calcaneus - 26%). There was no correlation between disease severity and microarchitecture. Areal bone mineral density (aBMD) measured by dual-energy X-ray absorptiometry (DXA) correlated well with parameters of cortical and trabecular microarchitecture. CONCLUSIONS: Hepatic cirrhosis deteriorates both trabecular and cortical microarchitecture, regardless of disease severity. Areal bone mineral density is diminished at all sites as a sign of generalized affection. In patients with hepatic cirrhosis, regardless of its origin or disease severity, aBMD measurements are an appropriate tool for osteologic screening.
Assuntos
Remodelação Óssea/fisiologia , Cirrose Hepática/patologia , Cirrose Hepática/fisiopatologia , Rádio (Anatomia)/patologia , Tíbia/patologia , Idoso , Biomarcadores/sangue , Densidade Óssea , Osso Esponjoso/diagnóstico por imagem , Osso Esponjoso/patologia , Estudos de Casos e Controles , Osso Cortical/diagnóstico por imagem , Osso Cortical/patologia , Feminino , Humanos , Cirrose Hepática/diagnóstico por imagem , Cirrose Hepática Alcoólica/diagnóstico por imagem , Cirrose Hepática Alcoólica/patologia , Cirrose Hepática Alcoólica/fisiopatologia , Masculino , Pessoa de Meia-Idade , Porosidade , Rádio (Anatomia)/diagnóstico por imagem , Tíbia/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Suporte de Carga/fisiologiaRESUMO
This study investigated the implication of a preceding high-trauma fracture on subsequent high- and low-trauma fractures at different skeletal sites in postmenopausal women and similarly aged men at an age range of 54 to 70 years. A preceding high-trauma fracture increases the risk of future low-trauma non-vertebral fractures including hip. INTRODUCTION: Little is known about the impact of the skeletal fracture site in conjunction with the severity of a past fracture (high- or low-trauma preceding fracture) and its effect on future fracture risk. METHODS: Patients with de novo high- and low-trauma fractures admitted to seven large trauma centers across Austria between 2000 and 2012 were stratified into sex and different age groups. Kaplan-Meier estimates, Cox proportional hazards regression models (HR), and likelihood calculations estimated effects of age, sex, and the anatomic region on the probability of a subsequent fracture in the same patient. RESULTS: Included in the study were 433,499 female and male patients at an age range of 0 to 100 years with 575,772 de novo high- and low-trauma fractures. In the age range of 54-70 years, subsequent fractures were observed in 16% of females and 12.1% of males. A preceding high-trauma fracture was associated with 12.9% of subsequent fractures, thereof 6.5% of high- and 6.4% of low-trauma in origin, usually at the hip, humerus, or pelvis. The highest effect sizes were observed for femur, humerus, and thorax fractures with hazard ratios (HR) of 1.26, 1.18, and 1.14. After splitting into high-trauma preceding and subsequent low-trauma fractures, the femoral neck (HR = 1.59), the female sex (HR = 2.02), and age (HR = 1.03) were discriminators for increased future fracture risk. CONCLUSIONS: Preceding high-trauma fractures increase the risk of future low-trauma non-vertebral fractures including hip. For each patient with a fracture, regardless of the severity of the trauma, osteoporosis should be taken into clinical consideration.
Assuntos
Fraturas Ósseas/epidemiologia , Adolescente , Adulto , Distribuição por Idade , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Áustria/epidemiologia , Criança , Pré-Escolar , Feminino , Fraturas do Colo Femoral/epidemiologia , Fraturas Ósseas/etiologia , Fraturas do Quadril/epidemiologia , Fraturas do Quadril/etiologia , Humanos , Lactente , Recém-Nascido , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Fraturas por Osteoporose/epidemiologia , Fraturas por Osteoporose/etiologia , Modelos de Riscos Proporcionais , Medição de Risco/métodos , Fatores de Risco , Distribuição por Sexo , Fatores Sexuais , Adulto JovemRESUMO
Car headlamp manufacturers have to optimise the headlamp spectrum to produce maximum visibility and minimal glare. There are very few investigations on the best spectrum for mesopic visibility and even less data on the spectrum of discomfort glare. We have performed pilot measurements to determine the spectral discomfort glare sensitivity under situations similar to night-driving conditions and conclude that it is not a simple additivity of the V(lambda) and the V' (lambda) functions.
Assuntos
Condução de Veículo , Ofuscação , Adulto , Condução de Veículo/psicologia , Sensibilidades de Contraste/fisiologia , Adaptação à Escuridão/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estimulação Luminosa/métodos , Projetos Piloto , Células Fotorreceptoras Retinianas Cones/fisiologia , Células Fotorreceptoras Retinianas Bastonetes/fisiologia , Autoavaliação (Psicologia)RESUMO
Problems related to the measurement of spectral sensitivity distribution are discussed. Special systems, an electromechanical one with servo-control and an all-electronic one using an instantaneous value measuring ratiometer, have been built and their performance tested. A number of problems generally encountered in such measurements can be eliminated by using the ratiometric system.