Niger. J. Physiol. Sci. 36 (December 2021): 159 – 164 www.njps.physiologicalsociety.com https://doi.org/10.54548/njps.v36i2.3 Full-Length Research Article Glycated Haemoglobin, Fasting Plasma Glucose, Plasminogen Activator Inhibitor Type-1, and Soluble Thrombomodulin Levels in Patients with Type 2 Diabetes Mellitus Edem M.S. 1 , *Akwiwu E.C. 2 , Akpotuzor J.O. 2 , Asemota E.A. 2 , Isong I.K. 2 1 Department of Haematology, University of Calabar Teaching Hospital, Calabar, Nigeria 2 Department of Medical Laboratory Science, College of Medical Sciences, University of Calabar, Calabar, Nigeria Summary: Diabetes mellitus has become increasingly prevalent over the years. The chronic hyperglycaemia of diabetes is associated with long-term damage, dysfunctions, and failure of different organs suggesting that the most effective tool to prevent complications is the effective control of hyperglycaemia itself. The study is set to determine the effect of glycemic control on plasminogen activator inhibitor type 1 (PAI-1), soluble thrombomodulin (STM) alongside fasting plasma glucose (FPG) and glycated hemoglobin (HbA1c) among type 2 diabetic subjects. One hundred diabetic subjects accessing care at the University of Calabar Teaching Hospital Calabar and 100 non –diabetics that served as controls were enrolled. Blood samples from participants were analyzed for FPG, HbA1c, PAI-1 and STM by standard methods. The result shows 74% of the diabetic to be females. Half of the diabetics were managed on only oral anti-diabetic drugs while the remaining half were either on insulin injection or a combination of oral and insulin injection. Poor glycemic control was observed in 56% of the studied subjects. The mean age of 54.69 ± 9.94 years for the diabetics was comparable to the age-matched controls (p=.097). Diabetics showed significantly higher FPG, HbA1c, PAI-1and STM (P=0.001) compared to control values. Correlations between STM, PAI 1 and glycated hemoglobin (figures 2 p=0.001, p =0.001) and STM, PAI-1 and FPG revealed significantly robust association (p=0.001, p=0.001). The study concludes that there is poor glycemic control among the treated diabetic subjects with PAI-1 and STM showing a very strong positive correlation with HbA1c than FPG. Keywords: Diabetes, Hyperglycemia, glycemic control, endothelial function ©Physiological Society of Nigeria *Address for correspondence: ecakwiwu@gmail.com; Tel: +234 8036777296 Manuscript received- December 2020; Accepted- August 2021 INTRODUCTION Diabetes mellitus has been reported to be increasingly prevalent over the years (IDF, 2017). while vascular complications have been identified among the important morbidity and mortality factors (WHO, 2019). Persistently increased value of hyperglycaemia in diabetes is associated with long-term damage, dysfunction, and failure of different organs suggesting that the most effective tool to prevent complications from organ impairment in diabetes is the regulation of glycaemia itself. Owing in part to the inconvenience of measuring fasting plasma glucose levels or performing an oral glucose tolerance test, coupled with the day-to-day variability seen in glucose assessment, an alternative glucose measurement for the management of diabetes was introduced known as the glycated haemoglobin (HbA1c). Initially identified as "unusual" haemoglobin in patients with diabetes, glycated haemoglobin is now regarded as an objective measure of glycaemic control. Reports have shown that glycated haemoglobin correlates with coagulation derangements (WHO, 2011; ADA, 2018: Akwiwu et al., 2020). Furthermore, recent endothelial studies done in diabetes suggest endothelial dysfunction, which is the hallmark of vascular diseases (Bretón‐Romero et al., 2018; Berra-Romani et al., 2020). The vascular endothelium, once thought to be simply a passive lining for blood vessels, is now recognized as a key determinant of vascular health. It has also become evident that endothelium is not an inert, single-cell lining covering the internal surface of blood vessels, but plays a crucial role in regulating vascular tone and structure (Iantorno et al., 2014; Brakemier et al., 2016). Other functions include the lining of the internal lumen of all the vasculature serving as an interface between circulating blood and vascular smooth muscle cells thus aiding as a physical barrier between the blood and tissues. Moreover, the endothelial cells facilitate a complex array of purposes in intimate interactions with the vascular smooth muscle cells, as well as cells within the blood compartment (Favero et al.,2014; Carrizzo et al.,2018). Therefore, injury or activation of the endothelium changes its regulatory functions and results in abnormal endothelial cell function. (Dogné et al., 2018; Schiattarella et al.,2018). Assessment of endothelial functions can be measured by the evaluation of endothelial cell markers. These Cell surface markers are proteins expressed on the surface of cells that often serve as indicators of specific cell types. Because endothelial activation often precedes overt endothelial dysfunction, biomarkers of the activated endothelium in serum or plasma may be detectable before