Sex differences between mid-life glycaemic traits and brain volume at age 70: a population-based study

Area of Science:

• Neuroscience
• Endocrinology
• Gerontology

Background:

• Midlife hyperglycemia is a growing concern.
• Previous studies linked higher HbA1c to reduced whole brain volume (WBV) in older women, but not men.
• The impact of various glycemic markers on brain structure requires further investigation.

Purpose of the Study:

• To investigate the association between midlife glycemic health markers and brain structure in later life.
• To determine if associations differ by sex.
• To explore relationships between fasting glucose, insulin resistance (HOMA2-IR), beta-cell function (HOMA-%B), and brain volumes (white and grey matter).

Main Methods:

• Utilized data from 453 participants (51% male) of the 1946 British Birth Cohort.
• Collected glycemic measures (fasting glucose, HOMA2-IR, HOMA-%B) at ages 60-64.
• Acquired brain MRI measures (WBV, white matter, grey matter) at approximately age 70.

Main Results:

• In women, higher midlife fasting glucose and insulin resistance were weakly associated with lower whole brain volume in later life.
• No significant associations were found between any glycemic marker and brain structure in men.
• Beta-cell function (HOMA-%B) showed no association with brain outcomes in either sex.

Conclusions:

• Women's brain health may be more susceptible to the effects of midlife hyperglycemia.
• These findings highlight potential sex differences in the neurobiological impact of glycemic dysregulation.
• Further research is warranted to understand the mechanisms underlying these sex-specific associations.