Shortened telomere length in bipolar disorder: a comparison of the early and late stages of disease

Objective: Bipolar disorder (BD) has been associated with increased rates of age-related diseases, such as type II diabetes, metabolic syndrome, osteoporosis, and cardiovascular disorders. Several biological findings have been associated with age-related disorders, including increased oxidative stress, inflammation, and telomere shortening. The objective of this study was to compare telomere length among participants with BD at early and late stages and age- and gender-matched healthy controls. Methods: Twenty-six euthymic subjects with BD and 34 healthy controls were recruited. Genomic DNA was extracted from peripheral blood and mean telomere length was measured using real-time quantitative polymerase chain reaction. Results: Telomere length was significantly shorter in both the early and late subgroups of BD subjects when compared to the respective controls (p = 0.002 and p = 0.005, respectively). The sample size prevented additional subgroup analyses, including potential effects of medication, smoking status, and lifestyle. Conclusion: This study is concordant with previous evidence of telomere shortening in BD, in both early and late stages of the disorder, and supports the notion of accelerated aging in BD.

Increased oxidative stress as a mechanism for decreased BDNF levels in acute manic episodes / Aumento do estresse oxidativo como um mecanismo para a diminuição dos níveis de BDNF em episódios maníacos agudos

OBJECTIVE AND METHOD: There is a growing amount of data indicating that alterations in brain-derived neurotrophic factor and increased oxidative stress may play a role in the pathophysiology of bipolar disorder. In light of recent evidence demonstrating that brain-derived neurotrophic factor levels are decreased in situations of increased oxidative stress, we have examined the correlation between serum thiobarbituric acid reactive substances, a measure of lipid peroxidation, and serum brain-derived neurotrophic factor levels in bipolar disorder patients during acute mania and in healthy controls. RESULTS: Serum thiobarbituric acid reactive substances and brain-derived neurotrophic factor levels were negatively correlated in bipolar disorder patients (r = -0.56; p = 0.001), whereas no significant correlation was observed in the control group.. CONCLUSION: These results suggest that alterations in oxidative status may be mechanistically associated with abnormal low levels of brain-derived neurotrophic factor observed in individuals with bipolar disorder.

OBJETIVO E MÉTODO: Existem crescentes evidências indicando que alterações no fator neurotrófico derivado do cérebro e aumento do estresse oxidativo podem estar envolvidos na fisiopatologia do transtorno bipolar. Considerando os achados recentes de que os níveis de fator neurotrófico derivado do cérebro estão diminuídos em situações de aumento de estresse oxidativo, nós testamos a correlação entre os níveis séricos de substâncias reativas do ácido tiobarbitúrico, um índice de peroxidação lipídica, e os níveis séricos de fator neurotrófico derivado do cérebro em pacientes portadores de transtorno bipolar durante mania aguda e em controles saudáveis. RESULTADOS: Os níveis séricos de substâncias reativas do ácido tiobarbitúrico e fator neurotrófico derivado do cérebro apresentaram uma correlação negativa em pacientes bipolares (r = -0,56; p = 0,001), enquanto não houve correlação significativa no grupo controle. CONCLUSÃO: Estes resultados sugerem que alterações de estresse oxidativo podem ser mecanisticamente associadas com níveis reduzidos de BDNF observados em indivíduos com transtorno bipolar.