WEDNESDAY, Jan. 9, 2019 (HealthDay News) -- Obesity is associated with lower gray matter brain volumes, according to a study published online Jan. 9 in Neurology.
Mark Hammer, Ph.D., from Loughborough University, and G. David Batty, D.Sc., from University College London, both in the United Kingdom, used cross-sectional data for 9,652 adults from the U.K. Biobank study to examine the correlation of body mass index (BMI) and waist-to-hip ratio (WHR) with brain volume.
The researchers found that higher levels of all obesity measures were related to lower gray matter volume (β coefficients for BMI per one standard deviation, WHR, and fat mass, −4,113, −4,272, and −4,590, respectively) after adjustment for a range of covariates. Compared with lean adults, the combination of overall obesity (BMI ≥30 kg/m²) and central obesity (WHR >0.85 and >0.90 for women and men, respectively) was associated with the lowest gray matter volume. Obesity was also associated with various regional brain volumes including caudate, putamen, pallidum, and nucleus accumbens in hypothesis-free testing with a Bonferroni correction. There was no correlation noted between obesity and white matter.
"It is unclear whether structural brain abnormalities drive obesity or whether obesity induces changes in gray matter volume that play a mechanistic role in future risk of neurodegeneration," the authors write.