Cerebrovascular disorders and glucolipotoxicity

Introduction. Rapid progression of atherosclerosis and, consequently, an increase in the risk of stroke and myocardial infarction are associated with the presence of diabetes mellitus (DM). There is a search for new biomarkers of these pathological conditions, including their preclinical forms, primarily associated with insulin resistance (IR), which underlies these metabolic disorders. Development of the glucose and lipid toxicity is considered as one of the decisive factors in the development of IR and atherosclerotic cardiovascular disease in the presence of disturbances in carbohydrate and lipid metabolism. The negative consequences of isolated glucose- and/or lipid toxicity are less than the presence of both conditions simultaneously, known as glucolipotoxicity. The triglyceride glucose (TyG) index, initially developed to assess such combined changes, is of great interest to researchers as a marker or predictor of diseases associated with IR.

Aim: to investigate the effect of glucolipotoxicity in patients with ischaemic stroke and to determine the diagnostic value of the TyG index.

Materials and methods. The study included 251 people: group 1 (n = 145) — patients with acute ischaemic stroke, and group 2 (n = 120) — patients with carotid atherosclerosis and chronic cardiovascular disease but without stroke or acute coronary disease in the medical history. The control group (n = 86) consisted of people without atherosclerosis or cardiovascular disease. All patients underwent comprehensive clinical, laboratory and imaging tests, including biochemical tests measuring the TyG index.

Results. Insulin resistance was found in all patient subgroups after acute stroke (irrespective of the ischaemic stroke subtype), and it was greater in patients with Type 2 DM (T2DM). The median TyG index value in patients with stroke and T2DM was 5 [4.8; 5.2], compared with 4.7 [4.6; 4.9] in patients with stroke but without T2DM. The TyG index was elevated in all patients with carotid atherosclerosis (median 4.9 [4.7; 5.2]), TyG index was statistically lower in people without atherosclerosis (median 4.6 [4.45; 4.7], p = 0.000).

When the TyG index values were evaluated using ROC curves as a predictor of significant carotid artery stenosis (lumen narrowing of 60% or greater), the area under the curve was 0.821 and the TyG threshold value was 5.3 for patients with T2DM, while these values were 0.9153 and 4.71 for people without T2DM, respectively.

Conclusion. The new method of glucolipotoxicity evaluation by calculating the TyG index has an important diagnostic and predictive role in identifying carotid atherosclerosis, IR, and metabolic syndrome in patients with cerebrovascular disease. This may allow us to stratify the patient categories that require vascular wall investigations, as well as to monitor treatment adequacy.