Obesity Causes Brain Damage in Adolescents According to MRI Studies.
Source: Thailand Medical News Nov 26, 2019 4 years, 11 months, 2 weeks, 3 days, 23 hours, 19 minutes ago
Radiological researchers using MRI have found signs of damage that may be related to inflammation in the
brains of
obese adolescents, according to a study being presented next week at the annual meeting of the Radiological Society of North America (RSNA).
The issue of
obesity in young people has become a significant public health problem. In the U.S., the percentage of children and
adolescents affected by
obesity has more than tripled since the 1970s, according to the Centers for Disease Control and Prevention. Data from the World Health Organization indicates that the number of overweight or
obese infants and young children ages five years or younger increased from 32 million globally in 1990 to 41 million in 2016.
Although
obesity is primarily associated with weight gain, recent evidence suggests that the disease triggers inflammation in the nervous system that could
damage important regions of the
brain. Developments in
MRI like diffusion tensor imaging (DTI), a technique that tracks the diffusion of water along the brain’s signal-carrying white matter tracts, have enabled researchers to study this
damage directly.
In the new study, researchers compared DTI results in 59
obese adolescents and 61 healthy
adolescents, ages 12 to 16 years. From DTI, the researchers derived a measure called fractional anisotropy (FA), which correlates with the condition of the
brain’s white matter. A reduction in FA is indicative of increasing damage in the white matter.
The findings showed a reduction of FA values in the
obese adolescents in regions located in the corpus callosum, a bundle of nerve fibers that connects the left and right hemispheres of the brain. Decrease of FA was also found in the middle orbitofrontal gyrus, a brain region related to emotional control and the reward circuit. None of the
brain regions in obese patients had increased FA.
Study co-author Dr Pamela Bertolazzi, a biomedical scientist and Ph.D. student from the University of São Paulo in Brazil told
Thailand Medical News via a phone interview, “
Brain changes found in obese adolescents related to important regions responsible for control of appetite, emotions and cognitive functions.”
This manner of damage correlated with some inflammatory markers like leptin, a hormone made by fat cells that helps regulate energy levels and fat stores. In some
obese people, the
brain does not respond to leptin, causing them to keep eating despite adequate or excessive fat stores. This condition, known as leptin resistance, makes the fat cells produce even more leptin.
The destructive condition of the white matter was also associated with levels of insulin, a hormone produced in the pancreas that helps regulate blood sugar levels.
Obese people often suffer from in
sulin resistance, a state in which the body is resistant to the effects of the hormone.
Dr. Bertolazzi added, “Our maps showed a positive correlation between
brain changes and hormones such as leptin and insulin. Furthermore, we found a positive association with inflammatory markers, which leads us to believe in a process of neuroinflammation besides insulin and leptin resistance.”
Additional studies are needed to determine if this inflammation in young people with obesity is a consequence of the structural changes in the
brain.
She added, “In the future, we would like to repeat
brain MRI in these
adolescents after multi-professional treatment for weight loss to assess if the
brain changes are reversible or not.”
The study other co-authors are Ricardo Uchida, D.Sc., Fabio L. Duran, D.Sc., Thaysa Neves, M.Sc., Elie Calfat, M.Sc., Naomi Costa, Estefania S. Fernandez, JoAnna D. Lima, Daniel A. Vasques, M.Sc., Cristiane Kochi, D.Sc., Marília Seelaender, D.Sc., Victor H. Otani, D.Sc., and Thais Z. Otani, D.
The details of the study will be published later at : https://www.rsna.org
