TOPLINE:
METHODOLOGY:
- Obesity is a well-known risk factor for poorer cognition and dementia, but the distribution of body fat may influence the risk and underlying mechanisms in the fat-brain-cognition pathway.
- The study examined associations of several abdominal fat depots with cognitive functioning and AD-related brain volumes.
- The study sample included 204 men and women from the Israel Registry for Alzheimer’s Prevention (mean age, 59 years; 60% women) who had a high AD risk due to parental family history.
- Abdominal MRI scans assessed fat stored as subcutaneous adipose tissue (SAT) beneath the skin, visceral adipose tissue (VAT) around abdominal organs, and ectopic, a harmful condition in which lipids accumulate in lean tissues such as the liver and pancreas.
- A structural volumetric brain MRI scan was undertaken by 142 participants to assess specific regions implicated in chosen previous research.
TAKEAWAY:
- High body mass index was associated with high pancreatic fat percentage in both men and women (P < .001) and with high SAT percentage in women (P = .01) but not with VAT percentage in either sex.
- After adjustment for cardiovascular risk factors, a higher pancreatic fat percentage was linked to lower global cognition (beta, −0.33; P = .02) and executive function (beta, −0.32; P = .02) in men, and with lower hippocampal volume in women (beta, −0.25; P = .03).
- In men only, a higher SAT percentage was associated with a lower middle frontal gyrus volume (beta, −0.27; P = .03), while a higher VAT percentage was linked to higher middle frontal gyrus (beta, 0.29; P = .03) and superior frontal gyrus volumes (beta, 0.31; P = .02).
- Hepatic fat was not associated with brain volumes or cognition in either men or women.
IN PRACTICE:
“These results suggest that already in midlife, abdominal fat accumulation may have deleterious effects on brain health, especially in men,” the authors wrote.
SOURCE:
This study was led by Sapir G. Shekhtman, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel, and published online in Obesity (Silver Spring).
LIMITATIONS:
No causal inferences could be drawn from this study due to its cross-sectional nature. It did not represent the population of middle-aged adults as a whole, but rather those at high risk of developing AD. Factors contributing to fat accumulation, such as menopausal status or treatment, inflammation, insulin resistance, daily exercise, and dietary factors, were not included in this study.
DISCLOSURES:
This work was supported by grants from the National Institutes of Health. The authors declared no conflicts of interest.
A version of this article appeared on Medscape.com.