A study of correlation of plasma fibrinogen levels with glycemic status in type 2 Diabetes Mellitus patients

Complications; Glycated hemoglobin; Plasma fibrinogen; Type 2 diabetes mellitus; Background: Plasma fibrinogen is an indicator of inflammation and endothelial dysfunction has been described as an independent risk factor for cardiovascular morbidity in type 2 Diabetes mellitus patients. Poor glycemic control has been reported to be associated with hyperfibrinogenemia and its complications. This study was aimed to find a correlation of mean fibrinogen level with glycemic control in complicated and uncomplicated cases of Type 2 Diabetes mellitus.


INTRODUCTION
Diabetes mellitus (DM) is a chronic metabolic disorder characterized by hyperglycemia and disturbances in carbohydrates, fats, and protein metabolism. 1 Type 2 DM which is characterized by peripheral insulin resistance accounts for more than 90% of the global diabetic population. 1 The global prevalence of DM in 2019 is estimated to be 9.3%, increasing to 10.2% by 2030. 2 DM is a hypercoagulable state with 75% of deaths due to cardiovascular diseases as a result of thrombotic complications. 3 Fibrinogen is an important constituent of the coagulation cascade and an important determinant of blood viscosity, platelet aggregation, and thrombus formation. Increased plasma levels of fibrinogen have been reported in patients of Type 2 DM. 4 . Plasma fibrinogen itself is determined by several modifiable and non-modifiable determinants like age, sex, smoking, hypertension, HbA1c, etc. So increased attention is needed to understand the disordered hemostatic mechanism in diabetes. 5 Hence this study is aimed to evaluate the correlation of age, duration of type 2 DM with plasma fibrinogen levels, and glycated hemoglobin levels in patients with type 2 DM for early detection, monitoring, and appropriate management to reduce morbidity and mortality associated with type 2 DM.

MATERIALS AND METHODS
This is a cross-sectional study conducted at the Department of Pathology of tertiary care rural hospital from 2016 to 2018. This study was approved by the Institutional Ethical Committee and written informed consent was taken from all the patients. One hundred eight patients of DM, aged ≥30 years of either sex were included, of which 39 cases were without any complications and 69 cases had different microvascular and macrovascular complications. Clinical details of these patients along with socio-demographic data were recorded from the hospital information system. Hundred of non-diabetic age and sex-matched controls who did not have any chronic liver diseases, chronic kidney diseases, and any known coagulation disorder were selected. Appropriate control selection for the study was based on history, previous investigations were done in this hospital/outside, and also information from the medical record department.
Inclusion criteria were diagnosed cases of type 2 DM with or without related complications. The patients with a history of hypercoagulability, thromboembolism, inherited coagulation disorders, cancer, pregnancy, recent surgery, etc, and patients who were receiving standard anticoagulant treatment were excluded from the study. Venous blood samples of all the participants (patients and controls) were collected in Ethylenediaminetetraacetic acid and citrate bulb and were subjected for platelet count, fibrinogen level, and HbA1c. Fibrinogen level was estimated using the Clauss technique, with 'FIBROQUANT' test kit marketed by Tulip diagnostic on Behnk coagulometer. 6 HbA1c assay was done by particle enhanced immunoturbidimetric Methodology. 7 Patient data were collected using a structural interview questionnaire and analyzed by the statistical package for social sciences (SPSS) program version 17. The Student's t-test was used to know the significant difference among the continuous variables between the 2 groups (DM type 2 patients in group 1 and controls in group 2). Pearson correlation (r) was done to assess the degree of association between variables in different groups. A p-value of <0.05 was considered statistically significant.

RESULTS
The study included 108 diagnosed patients of Type 2 DM of which 64 (59.3%) were males and 44 (40.7%) were females with a M: F ratio of 1.4:1. Analysis of clinical data and biochemical parameters using the t-test showed a significant correlation between variables such as age, duration of diabetes with HbA1c, and fibrinogen levels in patients with type 2 DM with and without complications.
Of the total 108 patients, 39 cases were Type 2 DM without complication and 69 cases were with different DM complications. The mean age of patients for uncomplicated Type 2 DM was 53.58±11.1years, for complicated DM was 57.85±11.33 years, and for the control group mean age was 54.33±12.13 years. Maximum patients of Type 2 DM with complications were found in the age group of 61-70 years (33.33%) followed by 51-60 years (30.43%).
Based on HbA1c values patients were categorized into three groups 5.5-6.8% (good control), 6.9-7.6% (fair control) and >7.6 % (poor control). ( Plasma fibrinogen levels and glycemic status in type 2 Diabetes mellitus  On comparing the duration of diabetes with fibrinogen levels in patients with 10 to 15 years duration, the mean fibrinogen level was found to be a maximum of 502±142.68 mg/dl as compared with other groups. By using the Pearson coefficient test, a positive correlation was found between the duration of diabetes and mean fibrinogen levels (r=0.295, p=0.002). (Table 3)

DISCUSSION
DM is a major health problem whose burden is evident in developing countries like India as well. 8 It is among the top 10 causes of death and was estimated to have caused four million deaths in adults in 2017 worldwide. 9 In 2019 a total of 7.7 million people (20- Also, the mean fibrinogen value was high 450.43±108.51 mg/dl in complicated cases as compared to 372.30 ±123.78 mg/dl in uncomplicated type 2 DM. 14,15 Thus, we concluded that levels of plasma fibrinogen are associated with the severity of type 2 DM.

Hyperfibrinogenemia in DM cases may be related to lowgrade inflammation and elevated cytokines particularly
Ghongade PV et al interleukin-6 which stimulate hepatocytes to produce fibrinogen, representing an important link between inflammation and hypercoagulation. 16 Peripheral insulin resistance and hyperglycemia also have a direct impact on fibrinogen levels, whose concentrations are correlated with insulin and pro-insulin levels in healthy subjects also. 16 In DM hyperfibrinogenemia is a result of a procoagulant state due to an increase in numbers of coagulation factors such as von-Willebrand factor, fibrinogen, plasminogen activator inhibitor 1, factor VII and thrombin antithrombin complexes particularly in association with microvascular and macrovascular complication and glycemic control. 17 However, the mechanism by which fibrinogen increases the risk of cardiovascular complications is not fully understood. The proposed mechanisms by which hyperfibrinogenemia promote atherosclerosis and thrombus formation are increased plasma viscosity, inflammation and endothelial injury, induction of RBC and platelet aggregation, the formation of fibrinogen degradation products (FDPs) which bind low-density lipoprotein and sequester more fibrinogen and FDPs and fibrinogen stimulate smooth cell proliferation and migration. 12,17 Besides, hyperfibrinogenemia was found to be associated with age, smoking, hypertension, glycemic control, and duration of type 2 DM. 18 The glycemic control affects fibrinogen levels, as relative deficiency of insulin in DM, results in differential protein synthesis i.e., a 29% decrease in albumin synthesis and a 50% increase in fibrinogen synthesis. Also, glycosylate fibrinogen is less susceptible to plasmin degradation. 19 We also studied the correlation of duration of type 2 DM in years and fibrinogen level. Among the patient with DM with 10 to 15 years duration, the mean fibrinogen level was found to maximum 502±142.68 mg/dl as compared to patients with lesser duration of DM (p=0.002). Similar observations were made by Gupta RK et al. 14 However Kafue DR et al 15 did not find any significant association between the duration of diabetes in years and fibrinogen level.
In present study diabetic patients were categorized into three groups depending upon the HbA1c values i.e., 5.5-6.8% (good control), 6.9-7.6% (fair control), and >7.6% (poor control Poor glycaemic control may lead to hypercoagulability because glucose causes a direct effect on the endothelium. Long-term hyperglycemia damages the endothelium by increasing glycosylation of proteins and lipids to form advanced glycation end products.23 Glycemic control in Indian diabetic patients is poor which has resulted in high morbidity and mortality associated with diabetic complications. However, in our study mean HbA1c value in total DM cases was 8.02±1.88 % which was lower than that in a study by Mohan V et al22 (9.2% in 20,554 patients of Type 2 DM). This difference is due to the small number of patients in our study. A significant positive correlation exists between age, duration of DM in years, plasma fibrinogen levels, and HbA1c.

CONCLUSIONS
Plasma fibrinogen levels are elevated in type 2 DM and this elevation was associated with poor glycemic control as evidenced by increased HbA1c levels. The other parameters which correlated with plasma fibrinogen levels were age and duration of DM in years. The patients in the 60-70 years of age group and having a history of DM for 10-15 years had higher fibrinogen levels compared to younger patients. Thus, lowering plasma fibrinogen levels could be an important approach to the prevention of cardiovascular complications in DM.