Leukocyte blood composition and inflammation index of the NLR (ratio of neutrophils to lymphocytes) in patients with newly diagnosed type 2 diabetes with different body mass index against the background of post-Covid

Abstract

Abstract. The coronavirus disease pandemic had a global impact on the health of people throughout the world, including the endocrine system, causing a significant disruption effect through unprecedented increase in mortality and morbidity. Among endocrine diseases, one of the most widespread is diabetes mellitus (DM). The global dramatic increase in the incidence of diabetes in the world today has become a
non-infectious pandemic. The data obtained so far confirm that at the debut of T2D in post-Covid, there are significant disorders of innate and adaptive immunity, which dictates the need for urgent study and in-depth fundamental understanding of the general pathophysiology and clinical, and immunological patterns of post-Covid pathogenesis in patients with T2D debuts with different body mass index (BMI), which potentially determines the choice of a therapeutic strategy in this category of patients. Despite the large number of publications devoted to the combination of СОVID-19 and T2D, these studies were mostly performed in T2D patients with different disease duration. At the same time, published data on the leukocyte composition, the inflammation index NLR (the ratio of the absolute number of neutrophils to the absolute number of lymphocytes) in the PC in patients with the debut of T2D in the post-Covid period are extremely limited and contradictory. There is almost no information on the relationship between systemic inflammation markers and BMI indicators in patients with newly diagnosed T2D in the post-Covid period. Thus, the main aim of the work was to study the total number of leukocytes, the leukocyte composition of PC and the index of inflammation of the NLR in patients with newly diagnosed T2D with different BMI against the background of the fall ill with covid. Results. The study involved 98 patients with T2D debut within 3 months after the previous coronavirus disease, with different BMI, and 94 patients with T2D debut with different BMI with the manifestation of the disease in the pre-pandemic period. The comparison groups consisted of 93 normoglycemic people after the previous coronavirus disease with different BMI and 88 normoglycemic people with different BMI without a history of covid. It was found that patients with the debut of T2D with different BMI in post-covid compared to patients with newly diagnosed T2D with different BMI in pre-covid period are characterized by significant leukocytosis (an increase in the total number of leukocytes by almost 1.5 times, p<0.001), neutrophilosis (an increase in absolute number of neutrophils by almost 2 times, p<0.001), monocytosis (an increase in the absolute number of monocytes by almost 2 times, p<0.001), lymphocytopenia (a decrease in the relative number of lymphocytes by almost 2 times, p<0.001) and an increase in the inflammation index of the NLR by more than 2 times (p<0.001), which indicates a cumulative increase in the level of systemic inflammation in patients with T2D debut after coronavirus disease. In order to more accurately determine the effect of BMI values in patients with T2D debut with different BMI in the post-covid period on the degree of changes in the leukocyte composition of the blood, the groups of patients with the debut of T2D in the pre- and post-Covid periods were divided into four subgroups depending on the BMI values: 1) with a normal BMI (<25.5 kg/m2); 2) BMI from 25.5 to 29.9 kg/m2; 3) BMI from 30 to 34.5 kg/m2; 4) BMI >35.0 kg/m2. It was established that progressive, depending on the BMI values, leukocytosis, neutrophilosis, monocytosis, lymphocytopenia and increase in the NLR index were characteristic of the entire cohort of patients with the debut of T2D in post-covid compared to patients with the newly diagnosed T2D in pre-covid, in whom leukocytosis, neutrophilosis, monocytosis and an increase in the NLR index were observed only in patients with newly diagnosed T2D with a BMI > 30.0 kg/m2, and relative lymphocytopenia (p<0.001) was characteristic only in patients with T2D in the pre-Covid period with a BMI >35.0 kg/m2. Similar changes in leukocyte composition, which were found in patients with T2D debut with different BMI in post-covid, but less significant, were also observed in normoglycemic people with different BMI in post-covid and were completely absent in normoglycemic people with different BMI in pre-covid, which indicates the key importance of altered post-coronavirus state of immunity in the pathogenesis of T2D debut in patients with different BMI after coronavirus disease. Conclusions. Changes in the leukocyte composition, namely the level of leukocytosis, neutrophilosis, monocytosis, lymphocytopenia and the values of the NLR index in patients with T2D debut depend not only on BMI values, but are also due to the systemic inflammatory state of the post-covide background, which strengthens the basis for T2D debut. The changes in the leukocyte composition that we identified in patients with T2D debut with different BMI in the post-covid period explain the two-way relationship between T2D and the coronavirus disease and determine the strategic choice of further pathogenetic therapy for this category of patients.