Systemic inflammation and menstrual cycle length in a prospective cohort study

Area of Science:

• Reproductive Endocrinology
• Inflammation Biology

Background:

• Local inflammation is crucial for normal ovulation.
• Chronic systemic inflammation, seen in obesity and PCOS, disrupts follicular dynamics.

Purpose of the Study:

• To investigate the association between systemic inflammation, measured by C-reactive protein (CRP), and menstrual cycle length.
• To analyze the relationship between CRP levels and both follicular and luteal phase lengths.

Main Methods:

• Secondary analysis of data from the prospective Time to Conceive cohort study.
• Multivariable linear mixed and marginal models were used, adjusting for various demographic and lifestyle factors.
• Serum CRP levels were measured on cycle days 2-4 in women aged 30-44 attempting conception.

Main Results:

• No linear association was found between CRP levels and overall menstrual cycle length.
• Elevated CRP (>10 mg/L) was associated with significantly increased odds of long menstrual cycles (≥35 days).
• High CRP levels correlated with longer follicular phases and increased odds of long follicular phases.

Conclusions:

• A potential pathophysiological link exists between systemic inflammation and menstrual cycle alterations.
• Further studies are required to elucidate whether inflammation causes cycle changes or if long cycles indicate elevated inflammation.