ABSTRACT
Background & objectives: The effects of vitamin K-dependent proteins in bone mineralization and vascular calcification and the implication of vitamin K epoxide reductase gene (VKORC1) 1173C>T polymorphism in warfarin sensitivity are well known. The main objective of the study was to investigate the relationship between VKORC1 1173C>T polymorphism, bone mineral density (BMD), and atherosclerosis (evaluated by intima-media thickness of the carotid artery and the presence of calcified plaques) in patients suspected to have osteoporosis or osteopenia and referred for BMD determination. Methods: VKORC1 1173C>T polymorphism was evaluated in 239 consecutive patients referred by their physicians for BMD measurement (dual energy X-ray absorptiometry at L2-L4 lumbar spine, femoral neck and total hip). Ultrasonography of the carotid arteries was performed, intima-media thickness (IMT) was measured and the presence of atherosclerotic calcified plaques was recorded. Results: In the patients with osteoporosis and osteopenia there was a higher frequency of TT genotype of VKORC1 1173C>T (P=0.04). The TT genotype was significantly more frequent in the osteoporotic group compared to the osteopenic group (P=0.01). The mean age and body mass index were lower in the patients with normal BMD and TT genotype (P=0.02, P=0.03). There was no correlation between the IMT and VKORC1 1173C>T genotype but the TT genotype had a significant association with the presence of calcified atherosclerotic plaques (P=0.05). This finding was not correlated with normal or pathologic BMD. Interpretation & conclusions: VKORC1 1173C>T polymorphism (TT genotype) was associated with osteoporosis and calcified plaques in the carotid artery in patients referred for BMD measurement. Different mechanisms are probably involved in these associations. TT genotype may serve as a potential genetic marker for the risk of OP and ATS.
ABSTRACT
CONTEXT AND OBJECTIVES: Controversy exists regarding the relationship between atherosclerosis and osteoporosis. The aim of this study was to determine the relationship between intima-media thickness (IMT) of the common carotid artery (CCA), presence of calcified atherosclerotic plaques and bone mineral density (BMD) evaluated by dual energy X-ray absorptiometry (DXA), in postmenopausal women. DESIGN AND SETTING: Cross-sectional study at Second Internal Medicine Clinic, Cluj-Napoca, Romania. METHODS: We studied the IMT (left and right CCA and mean IMT) and T-score (lumbar spine L2-L4, femoral neck and total hip) in 100 postmenopausal women (mean age 64.5 years). The presence of calcified atherosclerotic plaque and osteoporotic vertebral fractures was also noted. RESULTS: IMT in the left and right CCA and mean IMT were significantly associated with T-score measured for the lumbar spine L2-L4, femoral neck and total hip, with lower T-score, in the osteoporotic group than in the normal and osteopenic groups (P < 0.05). IMT had a significantly negative correlation with the lumbar spine T-score and femoral neck T-score; and mean IMT with lowest T-score. Mean IMT (P < 0.001), high blood pressure (P = 0.005) and osteoporotic vertebral fractures (P = 0.048) showed statistical significance regarding the likelihood of developing atherosclerotic plaque. CONCLUSIONS: In women referred for routine osteoporosis screening, the relationship between CCA, atherosclerosis and osteoporosis can be demonstrated using either cortical or trabecular BMD. Vertebral fractures may be considered to be a likelihood factor for atherosclerotic plaque development.
CONTEXTO Y OBJETIVOS: Hay controversias en cuanto a la relación entre la arterioesclerosis y la osteoporosis. El objetivo del estudio fue determinar la relación entre el espesor mío-intimal (EMI) de la arteria carótida común (ACC), la presencia de placas arterioescleróticas calcificadas, y la densidad mineral ósea (DMO) evaluada a través de absorciometría de rayos X de energía dual (DEXA) en mujeres posmenopáusicas. DISEÑO Y ENTORNO: Estudio transversal en la Segunda Clínica de Medicina Interna, Cluj-Napoca, Rumania. MÉTODOS: Hemos estudiado el EMI (ACC izquierda y derecha y EMI promedio) y el T-score (espina lumbar L2-L4, cuello femoral y cadera total) en 100 mujeres posmenopáusicas (edad promedia 64.5 años). Se ha observado también la presencia de las placas arterioescleróticas calcificadas y de la fractura vertebral osteoporótica. RESULTADOS: El EMI en ACC izquierda y derecha, como también el EMI promedio se ha asociado sobre todo con el T-score medido en la espina lumbar L2-L4, cuello femoral y cadera total o el valor más bajo del T-score, en el grupo osteoporótico, en comparación con el grupo normal y el osteopénico (P < 0.05). Se ha registrado una correlación significativamente negativa entre el EMI y el T-score de espina lumbar, el T-score del cuello femoral, y el EMI promedio con el T-score más bajo. El EMI promedio (P < 0.001), la alta presión (P = 0.005), y las fracturas vertebrales osteoporóticas (P = 0.048) demostraron tener una importancia estadística con respecto a la probabilidad de formación de placas arterioescleróticas. CONCLUSIONES: En el caso de las mujeres sometidas a screening rutinario para la osteoporosis, la relación entre ACC, arterioesclerosis y osteoporosis se puede demostrar utilizando sea la DMO cortical o trabecular. Las fracturas vertebrales se pueden considerar como un factor de probabilidad para el desarrollo de las placas arterioescleróticas.