Lipid oxidation in young patients with newly diagnosed bipolar disorder and their relatives

BACKGROUND: Oxidative stress may be involved in the pathophysiology of bipolar disorder (BD). Malondialdehyde (MDA), a product of fatty acid peroxidation has been proposed as a trait marker of BD associated with familial risk. However, little is known about MDA levels in young patients newly diagnosed with BD and their unaffected first-degree relatives (UR).

METHODS: In this substudy of the ongoing longitudinal "Bipolar Illness Onset study", we included baseline data and first, we compared fasting blood MDA levels in 130 young patients aged 15-25 years newly diagnosed with BD, 57 UR, and 88 healthy control individuals (HC). Second, we investigated associations between levels of MDA and illness variables in patients with BD. Third, we investigated associations between MDA levels and nucleoside damage by oxidation measured in urine. Fasting MDA levels from blood samples were measured using high-performance liquid chromatography (HPLC).

RESULTS: In linear mixed effect models, adjusted for age and sex, MDA levels did not differ between patients with BD, UR, and HC, respectively. In patients with BD, we found no associations between levels of MDA and duration of illness, number of affective phases, illness onset or oxidatively damaged RNA and DNA.

CONCLUSION: Against expectations, MDA levels did not differ between young patients with BD, UR, and HC, thus, our findings did not support MDA being a state or a trait marker of BD associated with familial risk.