RESUMO
BACKGROUND: To evaluate the effect of 1 year systemic arterial hypertension on 3-year allograft survival in children with kidney transplantation. METHODS: A retrospective study was carried out of pediatric patients submitted to kidney transplantation at the Universidade Federal de São Paulo (UNIFESP) between January, 1998 and January, 2003. Patients were classified as normotensive or hypertensive according to presence of hypertension within the first year after transplantation. Survival analyses were performed with the Kaplan-Meier survival method, and survival curves were compared with the log-rank test. A p value of < 0.05 was considered statistically significant. RESULTS: Prior to transplantation there were 86 patients (64%) and after 1 year, 70 children (52%) were classified as hypertensive, respectively. Overall, the 3-year graft survival was of 92.5%. Survival of the normotensive group was 95.3% and 90.0% for the hypertensive group; the difference was not statistically significant. CONCLUSION: Although the difference between the two groups was not statistically significant the higher survival of the normotensive group seems to be clinically significant and allows hypothesizing that arterial hypertension could be a risk factor for pediatric graft survival. However, due to limitations of the study it is impossible to affirm that hypertension is an independent risk factor for lower graft survival.
Assuntos
Sobrevivência de Enxerto , Hipertensão/complicações , Transplante de Rim , Adolescente , Brasil/epidemiologia , Criança , Pré-Escolar , Métodos Epidemiológicos , Humanos , Hipertensão/diagnóstico , Hipertensão/epidemiologia , Hipertensão/etiologia , Fatores de Risco , Fatores de Tempo , Transplante HomólogoRESUMO
OBJETIVO: Avaliar a influência da hipertensão arterial sistêmica com um ano de transplante renal na sobrevida do enxerto renal três anos após o transplante em crianças. MÉTODOS: Estudo observacional e retrospectivo na série de pacientes transplantados renais pediátricos da Universidade Federal de São Paulo (UNIFESP) no período de janeiro/1998 a janeiro/2003. Ao final do primeiro ano pós-transplante, os pacientes foram classificados em dois grupos: normotensos e hipertensos. A análise estatística de sobrevida foi através do método de Kaplan-Meier. A comparação entre grupos foi realizada utilizando-se o teste do "log-rank". Para os testes adotamos o limite de 5 por cento (α < 0,05) para rejeição da hipótese de nulidade. RESULTADOS: Antes do transplante 86 pacientes (64 por cento) e após um ano 70 indivíduos (52 por cento) foram classificados como hipertensos, respectivamente. A sobrevida do enxerto renal após três anos de transplante foi de 92,5 por cento para a amostra completa do estudo. O grupo de normotensos apresentou sobrevida de 95,3 por cento e os hipertensos 90 por cento; a diferença não foi estatisticamente significante. CONCLUSÃO: Apesar do resultado estatístico não ser significante, a diferença observada entre os dois grupos após três anos de transplante, de 5 por cento maior sobrevida nos indivíduos que eram normotensos um ano após o transplante, nos parece clinicamente significativa e nos permite levantar a hipótese de que a hipertensão arterial pode ser um fator de risco para a sobrevida do enxerto pediátrico. Entretanto, não nos seria possível afirmar que a hipertensão é fator de risco independente para menor sobrevida do enxerto devido às limitações do estudo.
BACKGROUND: To evaluate the effect of 1 year systemic arterial hypertension on 3-year allograft survival in children with kidney transplantation. METHODS: A retrospective study was carried out of pediatric patients submitted to kidney transplantation at the Universidade Federal de São Paulo (UNIFESP) between January, 1998 and January, 2003. Patients were classified as normotensive or hypertensive according to presence of hypertension within the first year after transplantation. Survival analyses were performed with the Kaplan-Meier survival method, and survival curves were compared with the log-rank test. A p value of < 0.05 was considered statistically significant. RESULTS: Prior to transplantation there were 86 patients (64 percent) and after 1 year, 70 children (52 percent) were classified as hypertensive, respectively. Overall, the 3-year graft survival was of 92.5 percent. Survival of the normotensive group was 95.3 percent and 90.0 percent for the hypertensive group; the difference was not statistically significant. CONCLUSION: Although the difference between the two groups was not statistically significant the higher survival of the normotensive group seems to be clinically significant and allows hypothesizing that arterial hypertension could be a risk factor for pediatric graft survival. However, due to limitations of the study it is impossible to affirm that hypertension is an independent risk factor for lower graft survival.
Assuntos
Adolescente , Criança , Pré-Escolar , Humanos , Sobrevivência de Enxerto , Hipertensão/complicações , Transplante de Rim , Brasil/epidemiologia , Métodos Epidemiológicos , Hipertensão/diagnóstico , Hipertensão/epidemiologia , Hipertensão/etiologia , Fatores de Risco , Fatores de Tempo , Transplante HomólogoRESUMO
Systemic arterial hypertension is a common complication among transplanted patients. The objective of this study was to investigate the risk factors for arterial hypertension after kidney transplantation in children. A retrospective study was carried out of 70 kidney transplants performed on patients under 18 years of age at the Hospital do Rim and Hipertensão, from January 1998 to June 2001. At the end of 6 months post transplant, the patients were classified into either normotensive ( n=31) or hypertensive ( n=39) groups. The following potential risk factors for arterial hypertension were studied: (1) hypertension before transplantation; (2) the glomerular filtration rate (GFR) at 1, 3, and 6 months post transplant; (3) acute rejection episodes; (4) cumulative dose of corticosteroids; (5) the presence of native kidneys; (6) symptomatic renal artery stenosis; (7) cold ischemia time greater than 24 h; (8) age and sex of the donor; (9) age of the recipient; (10) transplant type (living related or cadaveric donor); (11) the body mass index of recipients at the end of the follow-up period; and (12) delayed graft function. The two groups were comparable in terms of the etiology of renal insufficiency, age, gender, and immunosuppressive drugs. Among the risk factors studied, the sole factor showing a statistically significant association with arterial hypertension was the GFR at 3 and 6 months after transplantation. In the group of normotensive patients, GFRs were 92+/-29 and 83+/-20 ml/min per 1.73 m(2) at 3 and 6 months, respectively, whereas in the hypertensive patients, GFRs were 74+/-23 and 70+/-21 ml/min per 1.73 m(2) respectively. Hence, only the lower GFR can be considered a risk factor for hypertension in children within our sample. However, arterial hypertension might be a risk factor for the early onset of chronic allograft nephropathy; in this case, hypertension should be considered the cause of lower glomerular filtration. Our data do not permit us to distinguish between these two hypotheses. The known risk factors for hypertension following renal transplantation in adults were not confirmed in the present study. It remains unclear to us as to whether this means the etiology of hypertension differs in children, or if this is the result of a bias in patient selection.