Study of the Chemical Composition of Meibum in Patients with Type 2 Diabetes Mellitus

Relevance Hyperglycemia causes oxidative stress and metabolic disorders that can change the anatomical and functional state of the meibomian glands. This, in turn, affects the qualitative and quantitative composition of their secretion. Clinical studies demonstrate that the meibomian glands (MG) can be affected by various systemic diseases, including type 2 diabetes [1–4]. A study of retinal proteins in patients with proliferative diabetic retinopathy (PDR) and epiretinal membranes using mass spectrometry revealed 102 proteins in the PDR group and 31 in the membrane group. Increased expression of zinc-α2-glycoprotein and various apolipoproteins, as well as a decrease in the level of pigment epithelial factor, were detected. Mass spectrometry allows for accurate analysis of the composition of complex fluids, such as tears and meibum, through ionization of molecules. According to I. Butovich, this method in combination with liquid chromatography is the most informative for the analysis of the lipid spectrum of meibum. In tears, 17 classes of lipids have been identified, where non-polar ones make up about 82%. The study of the protein component of meibum is important, since it affects the properties of the tear film, especially in diabetics. Conclusion Various clinical studies show damage to the mammary glands in various systemic diseases, including type 2 diabetes. It has been shown that the severity of pathological changes in the meibomian glands may be associated with the duration of diabetes mellitus and changes in the chemical composition of the meibum. Key words: meibomian glands; dysfunction of the meibomian glands; type 2 diabetes mellitus; biomarker; meibum