Sex differences in inflammatory markers in bipolar disorder.

Area of Science:

• Neuroscience
• Immunology
• Psychiatry

Background:

• Chronic inflammation in the periphery and brain is linked to mood disorders.
• Elevated inflammatory markers may serve as a biomarker for bipolar disorder (BD).
• Sex differences in inflammatory markers are observed in the general population, often related to infections or surgeries.

Purpose of the Study:

• To investigate sex differences in serum levels of IL-6, TNF-α, CCL-11, and CRP in individuals with BD and healthy controls (HC).
• To compare these sex differences between the BD and HC groups.

Main Methods:

• Serum samples from 156 participants (49 women/45 men HC; 38 women/24 men BD) were analyzed over three baseline visits.
• Inflammatory markers (IL-6, TNF-α, CCL-11, CRP) were measured using electrochemiluminescence assays.
• General linear models examined effects of sex, diagnosis, and their interaction, controlling for smoking, BMI, and age.

Main Results:

• Individuals with BD had higher IL-6 levels than HC participants.
• TNF-α levels showed significant effects of sex and diagnosis, with higher levels in men with BD and lower levels in HC women.
• CCL-11 was higher in men than women overall.
• CRP levels were elevated in men with BD compared to HC men.

Conclusions:

• Men exhibited higher serum TNF-α than women, a difference more pronounced in the BD group.
• CRP was elevated in BD men compared to HC men.
• Future anti-inflammatory treatments for BD should account for potential sex-specific differences.