Inflammation as a link between depression and metabolic syndrome

Depression makes a major contribution to the overall global burden of disease, including the increased risk of a wide range of concomitant somatic pathology. А high percentage of mortality in psychiatric patients is attributed to physical diseases, mainly cardiovascular (CVD). Metabolic syndrome (MetS) is one of the risk factors for both the CVD and a frequent comorbid depression. The purpose of this review is to systematize data on the relationship between MetS and depression, in particular, on the shared pathogenetic mechanisms as systemic inflammation. The manuscript evaluates the issue of the use of hematological indices of systemic inflammation (HISIs) in the diagnosis of both MetS and affective pathology, and also provides data on new combined indicators, including the cellular link and lipidogram parameters. The latter include the ratios of lymphocytes and high-density lipoproteins (HDL) (Lymphocyte To High-Density Lipoprotein Ratio, LHR), neutrophils/HDL (Neutrophil To High-Density Lipoprotein Ratio, NHR), platelets/HDL (Platelet To High-Density Lipoprotein Ratio, PHR) and monocytes/HDL (Monocyte To High Density Lipoprotein Ratio, MHR). Understanding the relationship between hematological indices and metabolic syndrome in patients with depression can help identify individuals at high risk and identify timely preventive measures. Various clinical trials and studies indicate a link between hematological parameters and metabolic syndrome, but the question of choosing the most effective coefficients remains open. Further study of the problem can help identify potential risks of comorbid disorders and perform adequate preventive strategies.