Revista Brasileira de Ginecologia e Obstetrícia (Jun 2010)
Marcadores séricos de estresse oxidativo em mulheres inférteis com endometriose Serum markers of oxidative stress in infertile women with endometriosis
Abstract
OBJETIVO: comparar marcadores séricos de estresse oxidativo entre pacientes inférteis com e sem endometriose e avaliar a associação destes marcadores com o estadiamento da doença. MÉTODOS: estudo prospectivo envolvendo a inclusão consecutiva de 112 pacientes inférteis, não-obesas, com idade inferior a 39 anos, divididas em dois grupos: Endometriose (n=48, sendo 26 com endometriose mínima e leve - Estádio I/II e 22 com endometriose moderada e grave - Estádio III/IV) e Controle (n=64, com fator tubário e/ou masculino de infertilidade). Durante a fase folicular precoce do ciclo menstrual, foram coletadas amostras sanguíneas para análise dos níveis séricos de malondialdeído, glutationa e níveis totais de hidroperóxidos, por espectrofotometria e vitamina E, por cromatografia líquida de alto desempenho. Os resultados obtidos foram comparados da seguinte forma: os grupos endometriose versus controle; endometriose estádio I/II e controle, endometriose estádio III/IV e controle e entre os dois subgrupos de endometriose. Em todas as análises, foi considerado o nível de significância de 5% (pPURPOSE: to compare serum markers of oxidative stress between infertile patients with and without endometriosis and to assess the association of these markers with disease staging. METHODS: this was a prospective study conducted on 112 consecutive infertile, non-obese patients younger than 39 years, divided into two groups: Endometriosis (n=48, 26 with minimal and mild endometriosis - Stage I/II, and 22 with moderate and severe endometriosis - Stage III/IV) and Control (n=64, with tubal and/or male factor infertility). Blood samples were collected during the early follicular phase of the menstrual cycle for the analysis of serum malondialdehyde, glutathione and total hydroxyperoxide levels by spectrophotometry and of vitamin E by high performance liquid chromatography. The results were compared between the endometriosis and control groups, stage I/II endometriosis and control, stage III/IV endometriosis and control, and between the two endometriosis subgroups. The level of significance was set at 5% (p<0.05) in all analyses. RESULTS: vitamin E and glutathione levels were lower in the serum of infertile women with moderate/severe endometriosis (21.7±6.0 mMol/L and 159.6±77.2 nMol/g protein, respectively) compared to women with minimal and mild endometriosis (28.3±14.4 mMol/L and 199.6±56.1 nMol/g protein, respectively). Total hydroxyperoxide levels were significantly higher in the endometriosis group (8.9±1.8 µMol/g protein) than in the Control Group (8.0±2 µMol/g protein) and among patients with stage III/IV disease (9.7±2.3 µMol/g protein) compared to patients with stage I/II disease (8.2±1.0 µMol/g protein). No significant differences in serum malondialdehyde levels were observed between groups. CONCLUSIONS: we demonstrated a positive association between infertility related to endometriosis, advanced disease stage and increased serum hydroxyperoxide levels, suggesting an increased production of reactive species in women with endometriosis. These data, taken together with the reduction of serum vitamin E and glutathione levels, suggest the occurrence of systemic oxidative stress in women with infertility associated with endometriosis. The reproductive and metabolic implications of oxidative stress should be assessed in future studies.
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