A neat study from the August 2021 issue of Investigative Ophthalmology and Visual Science. High-Fat Diet Induces Inflammation of Meibomian Gland by Jinghua Bu et al studied mice that were fed a high-fat diet and how it affected the ocular surface. The giant grain of salt regarding this article is this.
mice showed extreme hyperlipidemia of greater than 700 mg/dL of cholesterol in serum,9 which is not common in patients with hyperlipidemia (generally over 200 mg/dL in serum)
As is often the case, these results are presented with animals 3+ times the levels of even what is considered high cholesterol in human patients. The other aspect to this is I couldn’t find what made up the high fat diet for the mice. If it was high in omega-6 fatty acids, the inflammatory issues those cause would be confounding to the whole idea here.
The science behind it, however, is compelling.
Slit-lamp microscope imaging showed milky secretions on the eyelid margins of mice after 4 weeks of the HFD, as well as in the conjunctival sac after 8 weeks of the HFD. The secretions became more prominent after 12 and 16 weeks
The high fat diet seemed to inhibit PPAR-γ gene expression which increased the inflammatory response. Rosiglitazone (aka Avandia) upregulates PPAR-γ gene expression. The mice treated with rosiglitazone had fewer inflammatory markers.
Rosiglitazone could also induce IL-10 expression in colitis and Parkinson’s disease models. Based on our current study, PPAR-γ is likely to continue to upregulate the expression of anti-inflammatory cytokines (such as IL-10) and decelerate the process of MGD.
I wouldn’t start treating MGD patients with Avandia. However, it shows one more part of the eye that can be affected in someone with metabolic syndrome.