Características da densidade mineral óssea em mulheres na pós-menopausa

• Autor(a) principal: Silva, Cristiane Fialho Ferreira da
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/3497
• topic: Mulheres - Doenças - Diagnóstico; Pós-menopausa; Densidade mineral óssea; Women - Diseases - Diagnosis; Postmenopausal; Bone mineral density; CNPQ::CIENCIAS DA SAUDE::EDUCACAO FISICA

Bone mineral density (BMD) is an important characteristic and it is associated with bone resistance against fracture risk. It is known that with aging and other associated factors there is accelerated loss that occurs with predisposition to fractures even with small efforts. Since postmenopausal women are the ones that present more risks, there are many studies that attempt to describe the factors that affect prevention, better early diagnosis of osteoporosis and their monitoring. Thus, physical activity has been described as a way to optimize BMD, preventing its deterioration and blood tests as bone biomarkers appear as a screening form of individuals in risk. However, there are many controversies regarding the influence in physical activity on BMD and the use of these bone biomarkers in the evaluation of BMD. The overall objective of this dissertation was to investigate the factors that influence BMD and the correlation of bone densitometry with parameters of physical activity and plasma levels of carboxy-terminal type I collagen (CTX) fraction in postmenopausal women. The specific objectives were to determine the main factors that are related to BMD measured by xivdensitometry by dual-energy absorption of x - ray (DXA), to assess the correlation of physical activity level, history of exercise and muscle strength with BMD, in addition to observing correlation of BMD measured with DXA with the values of bone biomarker CTX. In the first study, the presence of risk factors for decreased BMD in postmenopausal women were assessed, correlating them with BMD of the lumbar spine and right femur measured by DXA. 62 healthy women in postmenopausal period were evaluated, with average age of 56.82 ± 4.02 years old, as for the presence of risk factors for osteoporosis and physical activity level by the International Physical Activity Questionnaire (IPAQ), long form. Densitometry of the lumbar spine and proximal femur was performed, forming two groups: normal BMD and decreased BMD. It was found in this study that the Body Mass Index (BMI), age, weight, family history of osteoporosis, race, and time of menopause were the main determinant factors of BMD in postmenopausal women. The second study aimed to investigate the relation of strength tests, history of physical activity and habitual physical activity tests, assessed by pedometer with BMD at some bone sites in postmenopausal women. BMD was measured by DXA at bone sites in the lumbar spine (L1-L4), femur and forearm on the same sample of the first study. It was applied the Physical Activity History Questionnaire - Bone Loading History Questionnaire (BLHQ) modified and performed daily step count (pedometer). Muscle strength was measured by hands dynamometry tests, 30 seconds of bilateral biceps and sitting and standing in 30 seconds test. We conducted a 3-day food registering for measurement of daily intake of calcium and vitamin D. Several significant positive correlations between densitometry and muscle strength were observed, but at low magnitude (r < 0.50). And the most important finding of the study was the 5.5 times higher risk of women who did not practice physical activity from adolescence to adulthood of presenting decrease of BMD. The third study aimed to evaluate the correlation between DXA and CTX values, and also with the usual level of physical activity, physical activity history and strength tests in postmenopausal women. The same sample of women was assessed as for the level of habitual physical activity (pedometer), IPAQ - long form - and Physical Activity History Questionnaire, in addition to muscle strength tests. Densitometry of total xvbody, of lumbar spine, femur and forearms bilaterally, measurement of bone blood marker CTX, ionic calcium, phosphorus and PTH were performed. Among the two groups: control with normal BMD and group with decreased BMD there was no statistically significant differences for strength, level of habitual physical activity, history of physical activity and muscle strength tests in relation to CTX tests, but there was dependence of CTX compared to the values of total and the lumbar spine DXA, occurring low BMD when CTX was between moderate and high. This may indicate that this biomarker might be used as a screening form of individuals with risk for low BMD and increased fracture risk, and it may be an alternative routine blood test before the DXA exam.