Incidência de fraturas vertebrais e status de vitamina D em mulheres brasileiras na pós-menopausa com baixa massa óssea
Arquivos
Data
2017-02-22
Autores
Arantes, Henrique Pierotti 
Orientadores
Castro, Marise Lazaretti
Tipo
Tese de doutorado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Objetivos: Determinar a incidência de fraturas vertebrais em pacientes na pós-menopausa e os fatores de risco associados e conhecer a concentração sérica de vitamina D em mulheres de Recife, Salvador, Rio de Janeiro, São Paulo, Curitiba e Porto Alegre, e sua correlação com a latitude. Métodos: Braço brasileiro do estudo Arzoxifene Generations Trial, composto por mulheres na pós-menopausa (60 a 85 anos) com baixa massa óssea. Na primeira parte do estudo foi realizada análise de novas fraturas vertebrais no grupo placebo (n = 974), com seguimento de até cinco anos. As pacientes foram divididas em 2 estratos A e B. O estrato A era composto por pacientes com osteoporose densitométrica ou osteopenia e fratura vertebral presente no basal. Já o estrato B era composto somente por pacientes com osteopenia, sem fratura vertebral no basal O desfecho primário avaliado foi incidência de fraturas vertebrais, detectadas por Raios-X. Para fratura vertebral estimada foram utilizados taxa de incidência e modelo de regressão de Poisson. A segunda parte do estudo incluiu 1.933 pacientes com dosagem de 25 hidroxivitamina D (25OHD) no basal. Média e desvio padrão foram calculados para cada cidade e a técnica de Pearson para avaliar regressão linear entre 25OHD e latitude. Resultados: Taxa de incidência calculada de fraturas vertebrais foi de 7,7 (IC 95% de 5,4 a 10,9) por 1.000 pessoas-ano, com aumento em função da idade. Variáveis correlacionadas com novas fraturas foram idade (p=0,034), T-score da coluna lombar (p=0,001) e estrato A (grupo com osteoporose ou osteopenia com fratura vertebral prevalente), p=0,001 e fraturas prévias não vertebrais após a menopausa (p=0,019). Para cada diminuição de um desvio padrão no T-score,houve aumento de 46% no risco de fraturas (RR=1,46 (IC95% 1,22 a 1,62). A insuficiência da vitamina D (<50 nmol/L ou <20 ng/mL) foi comum (17%) e aumentou em função da latitude, atingindo 24,5% em Porto Alegre. Houve alta correlação entre a média da concentração de 25OHD em cada cidade e latitude (r=−0,88, p=0,02). Para cada grau de latitude em direção ao Sul, houve queda de 0,28 ng/mL na concentração sérica média de 25OHD. Conclusões: A taxa de incidência de fraturas vertebrais foi de 7,7 por 1.000 pessoas-ano, sendo que o T-score da coluna lombar foi o mais importante preditor. Alta prevalência de insuficiência de vitamina D em mulheres brasileiras na pós-menopausa com baixa massa óssea e esse percentual aumentou em função da latitude.
Objectives: The aim was to determine vertebral fracture incidence and risk factors in a Brazilian female population and investigate vitamin D status in cities located at different latitudes in Brazil, a large continental country, and the correlation with latitude. Methods: The source was the Brazilian database from the Generations Trial comprised by postmenopausal women (60 to 85 years old) with low bone mass. The sites included Recife, Salvador, Rio de Janeiro, São Paulo, Curitiba, and Porto Alegre. Vertebral fracture analysis from the Brazilian placebo group of the Arzoxifene Generations Trial (n=974) followed for up to 5 years. The primary endpoint was new vertebral fractures, detected by X-Ray. Crude and adjusted incidence rates of vertebral fractures were estimated and the Poisson regression model was used. The second part of this study included 1,933 osteopenic or osteoporotic postmenopausal women with 25OHD measurements. Mean and standard deviation and Pearson correlation were calculated. Results: Incidence rate was 7.7 (95% CI of 5.4 to 10.9) per 1,000 person-years (PY), increasing according to age. Variables correlated with new vertebral fracture were age (p=0.034), lumbar spine T-score, stratum A (p=0.001 for both), and previous nonvertebral fracture after menopause (p=0.019). Fracture risk increased by 46% for each unit reduction in LS T-score (RR=1.46, CI 95% 1.22 to 1.62, p=0.001). Vitamin D insufficiency (<50 or <20 ng/mL) was common (17 %) and increased according to latitude, reaching 24.5 % in Porto Alegre. The correlation between mean 25OHD levels in each site and latitude was very high (r=−0.88, p=0.02).Conclusions: Incidence rate of vertebral fracture of 7.7 per 1,000 PY, being LS T-score the most important predictor. There was a high percentage of postmenopausal women with low bone mass with vitamin D insufficiency in Brazil, even in cities near the equator, and this percentage progressively increases with more southern latitudes.
Objectives: The aim was to determine vertebral fracture incidence and risk factors in a Brazilian female population and investigate vitamin D status in cities located at different latitudes in Brazil, a large continental country, and the correlation with latitude. Methods: The source was the Brazilian database from the Generations Trial comprised by postmenopausal women (60 to 85 years old) with low bone mass. The sites included Recife, Salvador, Rio de Janeiro, São Paulo, Curitiba, and Porto Alegre. Vertebral fracture analysis from the Brazilian placebo group of the Arzoxifene Generations Trial (n=974) followed for up to 5 years. The primary endpoint was new vertebral fractures, detected by X-Ray. Crude and adjusted incidence rates of vertebral fractures were estimated and the Poisson regression model was used. The second part of this study included 1,933 osteopenic or osteoporotic postmenopausal women with 25OHD measurements. Mean and standard deviation and Pearson correlation were calculated. Results: Incidence rate was 7.7 (95% CI of 5.4 to 10.9) per 1,000 person-years (PY), increasing according to age. Variables correlated with new vertebral fracture were age (p=0.034), lumbar spine T-score, stratum A (p=0.001 for both), and previous nonvertebral fracture after menopause (p=0.019). Fracture risk increased by 46% for each unit reduction in LS T-score (RR=1.46, CI 95% 1.22 to 1.62, p=0.001). Vitamin D insufficiency (<50 or <20 ng/mL) was common (17 %) and increased according to latitude, reaching 24.5 % in Porto Alegre. The correlation between mean 25OHD levels in each site and latitude was very high (r=−0.88, p=0.02).Conclusions: Incidence rate of vertebral fracture of 7.7 per 1,000 PY, being LS T-score the most important predictor. There was a high percentage of postmenopausal women with low bone mass with vitamin D insufficiency in Brazil, even in cities near the equator, and this percentage progressively increases with more southern latitudes.