Glycemic control and its impact on oxidative stress biomarkers in type 2 diabetic patients treated with metformin: a cross-sectional analysis / Controle glicêmico e seu impacto em biomarcadores de estresse oxidativo em pacientes diabéticos tipo 2 tratados com metformina: uma análise transversal

AIMS: Evidence shows that diabetic patients may be predisposed to oxidative stress owing to increased glyco-oxidation and lipid peroxidation processes in consequence of chronic hyperglycemia. However, there is dearth of information whether glycemic control positively affects the antioxidant defense system in type 2 diabetes mellitus (T2DM). We investigated the potential association between glycemic control and oxidative stress biomarkers in controlled and uncontrolled diabetic states. METHODS: After obtaining ethical clearance, we included patients receiving metformin with glycated hemoglobin A1c ˂7.0% (glycemic control); newly diagnosed T2DM patients without glycemic control with hemoglobin A1c ˃7.0%; and apparently healthy normoglycemic individuals. The following biomarkers were determined: fasting glycemia level, malondialdehyde, glutathione peroxidase activity, catalase activity, total antioxidant capacity and total cholesterol level. The comparisons between the groups were made by ANOVA. RESULTS: The participants were 260 in number: 80 with controlled diabetes, 80 uncontrolled and 100 controls. All participants were between 40 and 71 years old. Fasting glycemia level and hemoglobin A1c showed significant reductions (p<0.05) in controlled T2DM against the uncontrolled T2DM group, all the same both were significantly higher (p<0.05) against the controls. Likewise, malondialdehyde levels showed significant elevations (p<0.05) correspondingly in both uncontrolled and controlled T2DM against the controls, accompanied with significant reductions (p<0.05) in the antioxidative enzyme activities (glutathione peroxidase activity and catalase activity) and total antioxidant capacity levels against the controls. In addition, total cholesterol was significantly reduced (p<0.05) in controlled T2DM against both uncontrolled T2DM and controls, respectively. There were significant correlations between hemoglobin A1c and oxidative stress biomarkers (p<0.05). CONCLUSION: There was no remarkable difference in oxidative stress states between glycemic controlled and uncontrolled T2DM, despite differences in their fasting glycemia and glycated hemoglobin levels. Our data, therefore, suggest that chronic hyperglycemia and possibly anti-diabetic medication may both equally associate with oxidative stress.

OBJETIVOS: Evidências mostram que pacientes diabéticos podem estar predispostos ao estresse oxidativo devido ao aumento dos processos de oxidação da glicose e peroxidação lipídica em consequência da hiperglicemia crônica. No entanto, há escassez de informações se o controle glicêmico afeta positivamente o sistema de defesa antioxidante no diabetes mellitus tipo 2. Esse estudo investiga a possível associação entre controle glicêmico e biomarcadores de estresse oxidativo em estados glicêmicos controlados e não controlados. MÉTODOS: Após a liberação da comissão de ética, o estudo incluiu pacientes em uso de medicação hipoglicemiante (metformina) com hemoglobina glicosilada A1c ˂7,0% (diabetes controlado), pacientes recém-diagnosticados com diabetes mellitus tipo 2 sem controle glicêmico e com hemoglobina A1c ˃7,0% e indivíduos normoglicêmicos aparentemente saudáveis. Foram determinados os seguintes biomarcadores: glicemia de jejum, malonaldeído, atividade da glutationa peroxidase, atividade de catalase, capacidade antioxidante total e nível de colesterol total. A comparação entre os grupos foi feita pela ANOVA. RESULTADOS: Foram incluídos 260 participantes: 80 com diabetes controlada, 80 não controlada e 100 controles. Todos os participantes tinham entre 40 e 71 anos. A glicemia de jejum e a hemoglobina glicosilada foram significativamente menores (p<0,05) nos diabéticos controlados comparado aos não controlados, e todos os diabéticos apresentaram valores significativamente maiores (p<0,05) que os controles. Da mesma forma, os níveis de malonaldeído foram significativamente maiores (p<0,05) nos diabéticos (controlados e não controlados), assim como valores das atividades antioxidantes (glutationa peroxidase e catalase) e nos níveis de capacidade antioxidante foram significativamente menores (p<0,05) frente aos controles. Além disso, o colesterol total foi significativamente menor (p<0,05) nos diabéticos controlados quando comparados aos não controlados e controles, respectivamente. Houve correlações significativas entre a hemoglobina glicosilada e do estresse oxidativo (p<0,05). CONCLUSÃO: Não houve diferença significativa nos estados de estresse oxidativo entre os diabéticos controlados e não controlados, apesar das diferenças nos níveis de glicose plasmática e hemoglobina glicosilada. Nossos dados, portanto, sugerem que a hiperglicemia crônica e, possivelmente, a medicação antidiabética pode associar-se igualmente ao estresse oxidativo.

Molecular detection of pneumocystis jirovecii in patients with respiratory tract infections.

BACKGROUND: Pneumocystis jirovecii, formerly known as P. carinii, is an opportunistic fungus causing Pneumocystis carinii pneumonia especially in immunocompromised patients. AIM: The aim of this study was to detect P. jirovecii in sputum samples from patients suspected of having respiratory tract infections. MATERIALS AND METHODS: In this study, 230 acid fast bacilli negative sputum samples from 230 patients presenting with respiratory tract infections submitted to three teaching hospitals' medical microbiology laboratories in Osun and Oyo States, Nigeria for routine investigation were examined for P. jirovecii by microscopical and polymerase chain reaction methods. RESULTS: P. jirovecii cysts were observed in 15 (6.5%) samples and polymerase chain reaction was positive for 29 (12.6%) samples out of 230 samples examined. It was observed that the detection of P. jirovecii was associated with age (P < 0.05) while there were no associations between diagnosis, sex, and prevalence of P. jirovecii (P > 0.05). Polymerase chain reaction was showed to be a better method for the detection of P. jirovecii based on the 51.7% sensitivity and 100% specificity of the microscopy. CONCLUSION: The study concluded that P. jirovecii is prevalent in patients with respiratory tract infections in hospitals from the southwestern part of Nigeria and should be included in diagnosis of these infections in this part of the world.