The obesity rate
in America is rapidly rising especially with more fast food chains and less
home grown fruits and vegetables. With this rise in obesity comes a rise in
several different diseases such as diabetes and asthma prevalent in children. Asthma
is one of the most common diseases in children and even more common in children
that are overweight or obese. There are many reasons for this being the case. With
obese children, there is a skewed immune response in a specific cell called the
T-helper type 1. This is found in the pulmonary tract and can be traced to
pulmonary deficits. High-density lipoprotein (HDL) is not found as much as it
should be with greater levels of low-density lipoprotein (LDL). Insulin
resistance also increases because of increasing obesity which in turn mediates
the association of the Th1 polarization and the pulmonary function. This
hinders breathing and being able to fully digest foods because of the lack of
insulin being secreted.
The studies have shown that there is
a definite obesity-related asthma phenotype and we have been able to identify
the complex relationship between metabolic dysregulation, systemic inflammation,
and pulmonary function deficits in children that are obese with asthma.
https://www.ncbi.nlm.nih.gov/pubmed/29161075
https://www.ncbi.nlm.nih.gov/pubmed/29161075
When I saw that you were discussing asthma in children and the link to obesity, I immediately remembered a recent study I read that suggested moderate-to-severe asthma is more common in women than men and in boys than in girls as a result of testosterone concentrations. More specifically, men have fewer airway inflammations as a result of allergic reactions. I have a lot of allergies, often to the most basic ingredients like rice, wheat, soy, eggs, tomatoes, etc. so my weight has fluctuated greatly over the years. I would often have asthma attacks after accidentally eating something or petting a dog. But I haven't had an asthma attack since I was in middle school. My allergist said that sometimes we grow out of our asthma as we age. I just accepted it and moved on.
ReplyDeleteILC2 is a rare group of cells circulating in the blood that release cytokines which stimulate CD4+ TH2 cells. TH2 cells secrete IL-4 and IL-5 which stimulate IgE and eosinophil extravasation. IgE is the primary molecule in allergies and is generally adapted to fight parasitic infections. The paper I read found that women had greater levels of circulating ILC2 - nearly double that of men - leading to more and stronger episodes of asthma. It seems that a downstream molecule derived from testosterone called 5α-dihydrotestosterone. This endocrine hormone decreases the concentrations of ILC2 in the lungs, without decreasing peripheral blood concentrations. As males produce more testosterone, they have significantly reduced ILC2 levels.
I mention this because I could not find anything that mentioned the interaction between childhood obesity and testosterone levels and ILC2 activation. I wonder if there is a long-term therapeutic remedy for asthma in the form of a 5α-dihydrotestosterone medication, but there must be off-target effects that should be explored first. Regardless, I thought this would be interesting to explore.
http://www.cell.com/cell-reports/fulltext/S2211-1247(17)31590-5