Plasminogen activator inhibitor-1 and HbA1c defined prediabetes: the Guangzhou Biobank Cohort Study-CVD

The role of fibrinolysis in the development of prediabetes-associated coronary heart disease: a focus on the plasminogen activator inhibitor -1 and its potential use as a predictive marker in diet-induced prediabetes

Introduction

Type 2 diabetes mellitus (T2DM) is associated with an increased risk of cardiovascular diseases (CVD). However, the onset of T2DM is preceded by prediabetes, which is associated with sedentary lifestyles and consumption of high-calorie diets. Studies have shown that impaired glucose homeostasis creates an environment for developing T2DM-related complications. Using a high-fat-high-carbohydrate diet-induced prediabetes animal model, this study sought to assess the risk factors of coronary heart disease (CHD) in diet-induced prediabetes and identify biomarkers that can be used for early detection of prediabetes-associated CHD.

Methods

Male Sprague Dawley rats were randomly grouped into two groups and were kept on different diets for 20 weeks (n = 6 in each group). One group was fed standard rat chow to serve as a non-prediabetes (NPD) control, while the other group consumed a high-fat-high-carbohydrate diet to induce prediabetes (PD). Post induction, the homeostasis model assessment- insulin resistance (HOMA-IR) and glycated haemoglobin (HbA1c) was used to test for insulin resistance. Body weight, mean arterial pressure (MAP), resting heart rate (HR), inflammatory cytokines (C-reactive protein (CRP), tumor necrosis factor (TNF-α), interleukin-6 (IL-6)), lipids (total cholesterol (TC), triglyceride (TG), lipoproteins (HDL, LDL, VLDL)), endothelial function (endothelial nitric oxide (eNOS), endothelin -1 (ET-1)), fibrinolysis (plasminogen activator inhibitor-1 (PAI-1)) were all measured to assess the risk of CHD. All data were expressed as means ± S.E.M. Statistical comparisons were performed with Graph Pad. Instat Software using Student's two-sided t-test. The Pearson correlation coefficient and linear regression were calculated to assess the association. The value of p < 0.05 was considered statistically significant.

Results

There was significant insulin resistance accompanied by significantly increased HbA1c and body weight in PD compared to NPD. Simultaneously, there was a significant increase in inflammatory cytokines in PD compared to NPD. This was accompanied by significantly increased TG and VLDL and endothelial dysfunction in PD. The association between HOMA-IR and PAI-1 was insignificantly positive in NPD, whereas a significantly strong positive association was observed in PD.

Conclusion

There is a positive correlation between insulin resistance and PAI-1 during prediabetes; therefore, suggesting that prediabetes increases the risk of developing vascular thrombosis. The current therefore study warrants further investigation on PAI-1 and other markers of fibrinolysis for the early detection of thrombosis and risk of CHD in prediabetes.

Plasminogen Activator Inhibitor-1 in poorly controlled vs well controlled Type-2 Diabetes Mellitus patients: A case-control study in a district hospital in Ghana

BACKGROUND

Hypofibrinolysis resulting from the up-regulation of plasminogen activator inhibitor-1 (PAI-1) usually occurs in patients with type 2 diabetes mellitus (T2DM), rendering them hypercoagulable. This study assessed the plasma antigen and activity levels of the PAI-1 enzyme in T2DM patients in a district hospital in Ghana.

METHODS

This was a hospital-based case-control study conducted from December 2018 to May 2019 at Nkenkaasu District Hospital. Sixty subjects with T2DM (30 T2DM subjects with good glycemic control and 30 with poor glycemic control), and 30 apparently healthy blood donors were recruited into the study. Blood specimens were collected for complete blood count, lipid profile, PAI-1 Ag and PAI-1 activity levels. A pre-tested questionnaire was used to obtain demographic and clinical information. The data was analyzed using SPSS version 22.0.

RESULTS

Elevated PAI-1 Ag and activity levels were observed in the T2DM subjects compared to the healthy controls, with the levels and activity significantly higher (PAI-1 Ag; p< 0.001, PAI-1 activity level; p = 0.004) in the T2DM subjects with poor glycemic control in comparison to those with good glycemic control. A significant positive correlation was observed between HbA1c and PAI-1 enzymes. PAI-1 Ag levels significantly increased along with increased total cholesterol (Β = 0.262, p = 0.033), triglyceride (Β = -0.273, p = 0.034) and HbA1c (Β = 0.419, p = 0.001). Similarly, PAI-1 activity level was associated with total cholesterol (Β = 0.325, p = 0.009), triglyceride (Β = -0.262, p = 0.042), HbA1c (Β = 0.389, p = 0.003) and VLDL-c (Β = -0.227, p = 0.029).

CONCLUSION

PAI-1 antigen/activity is enhanced in poorly controlled Ghanaian T2DM subjects. The hypercoagulable state of the affected individuals put them at higher risk of developing cardiovascular diseases. Good glycemic control to regulate plasma PAI-1 levels is essential during T2DM lifelong management. Markers of fibrinolysis should be assessed in these individuals and appropriate anticoagulants given to prevent thrombosis and adverse cardiovascular diseases.

The evaluation of the role of BMI and insulin resistance on inflammatory markers, PAI-1 levels and arterial stiffness in newly diagnosed type 2 diabetes mellitus patients

BACKGROUND

Increased cardiovascular risk, represented by endothelial inflammation, probably starts with the very first course of type-2 diabetes (T2DM). Almost 85.2% of all T2DM patients are overweight or obese. Thrombosis accounts 80% of all deaths in patients with diabetes. The thrombotic-fibrinolytic equilibrium shifts in favor of thrombosis by plasminogen activator inhibitor-1 (PAI-1). PAI-1 secretion is induced primarily by CRP. PAI-1 overexpression predisposes unstable plaque development. The contribution of obesity and diabetes to this process is not clearly understood. In this study, we aimed to investigate comparison of inflammatory markers, PAI-1 levels and arterial stiffness according to BMI and impaired glucose metabolism in patient with newly diagnosed T2DM.

METHODS

Newly diagnosed 60 T2DM patients were enrolled. Demographics and measurements were noted. Liver (AST, ALT), kidney (urea, creatinine, albumin/creatinine ratio), metabolic (fasting blood glucose, post-prandial blood glucose, insulin, c-peptide, HbA1c, total cholesterol, low-density lipoprotein [LDL], high-density lipoprotein [HDL], triglyceride) parameters, inflammatory markers [hsCRP, fibrinogen]), PAI-1 levels and pulse wave velocity was measured from all participants. The results were compared.

RESULTS

Inflammatory markers and PAI-1 levels were significantly elevated in obese group compared to overweight participants. The correlation analysis showed that waist and hip circumferences, high-sensitive CRP, fibrinogen and PAI-1 levels were positively correlated with BMI but not with HbA1c levels.

CONCLUSIONS

The results of our study showed that lipid levels, glycemic and blood pressure values of the obese and overweight patients were similar. BMI affects inflammatory markers and PAI-1 levels independent of glucose regulation and insulin resistance in newly diagnosed T2DM. According to the current study BMI is found to be more prominent in terms of inflammatory markers and PAI-1 levels compared to insulin resistance and impaired glucose metabolism in newly diagnosed T2DM.

Exposure to Low Doses of Dechlorane Plus Promotes Adipose Tissue Dysfunction and Glucose Intolerance in Male Mice

The prevalence of type 2 diabetes (T2D) continues to increase worldwide. It is well established that genetic susceptibility, obesity, overnutrition and a sedentary life style are risk factors for the development of T2D. However, more recently, studies have also proposed links between exposure to endocrine-disrupting chemicals (EDCs) and altered glucose metabolism. Human exposure to environmental pollutants that are suspected to have endocrine disruptor activity is ubiquitous. One such chemical is Dechlorane Plus (DP), a flame retardant, that is now detected in humans and the environment. Here we show that exposure of mice to low, environmentally relevant doses of DP promoted glucose intolerance in mice fed a high-fat diet independent of weight gain. Furthermore, DP had pronounced effects on the adipose tissue, where it induced the development of hypertrophied white adipose tissue (WAT), and increased serum levels of resistin, leptin, and plasminogen activator inhibitor-1. In addition, DP exposure induced "whitening" of brown adipose tissue (BAT), and reduced BAT uncoupling protein 1 expression. Importantly, some of these effects occurred even when the mice were fed a regular, low-fat, diet. Finally, WAT adipogenic markers were reduced with DP treatment in the WAT. We also show that DP directly inhibited insulin signaling in murine adipocytes and human primary subcutaneous adipocytes in vitro. Taken together, our results show that the exposure to low and environmentally relevant levels of DP may contribute to the development of T2D.

Estimated Association Between Cytokines and the Progression to Diabetes: 10-year Follow-Up From a Community-Based Cohort

CONTEXT

The long-term association between multiple cytokines and progression to diabetes is still uncertain.

OBJECTIVE

To identify which cytokines could predict progression to prediabetes and type 2 diabetes over 10 years.

METHODS

The study included 912 participants aged 40 to 69 years at baseline from the Ansung cohort, part of the Korea Genome Epidemiology Study. At baseline, a 75-g oral glucose tolerance test and 8 cytokines were measured: plasminogen activator inhibitor 1 (PAI-1), resistin, interleukin 6, leptin, monocyte chemoattractant protein 1, tumor necrosis factor alpha, retinol binding protein 4 (RBP4), and adiponectin. People with normal glucose tolerance (NGT, n = 241) and prediabetes (n = 330) were followed-up biennially for 10 years. Multinomial logistic regression analysis was used to evaluate the predictability of cytokines on the new-onset prediabetes and type 2 diabetes.

RESULTS

At 10 years, 38 (15.8%) and 82 (34.0%) of those with NGT had converted to prediabetes and type 2 diabetes, respectively. Of those with prediabetes, 228 (69.1%) had converted to type 2 diabetes. In people with NGT or prediabetes at baseline, the highest tertile of RBP4 was associated with a 5.48-fold and 2.43-fold higher risk of progression to type 2 diabetes, respectively. The odds for converting from NGT to prediabetes in the highest tertile of PAI-1 and the lowest tertile of adiponectin were 3.23 and 3.37, respectively. In people with prediabetes at baseline, those in the highest tertile of resistin were 2.94 time more likely to develop type 2 diabetes (all P < 0.05).

CONCLUSIONS

In this 10-year prospective study, NGT with higher serum RBP4 and PAI-1, and with lower adiponectin were associated with new-onset prediabetes and type 2 diabetes.

Performance of plasminogen activator inhibitor-1 as a biomarker in patients undergoing coronary angiography: Analytical and biological considerations

INTRODUCTION AND OBJECTIVE

Target lesion failure continues to limit the efficacy of percutaneous coronary intervention despite advancements in stent design and medical therapy. Identification of biomarkers to risk stratify patients after percutaneous coronary intervention has the potential to focus therapies on cohorts with increased benefits. Plasminogen activator inhibitor-1 has been identified as a candidate biomarker. Herein, we evaluate biological variables which impact plasminogen activator inhibitor-1 levels and analytical characteristics which impact its utility as a biomarker in humans.

METHODS

Plasma plasminogen activator inhibitor-1 was measured in 689 patients undergoing coronary angiography. Plasminogen activator inhibitor-1 levels were measured. Clinical and procedural characteristics were collected in a prospective registry.

RESULTS

Plasma plasminogen activator inhibitor-1 analytical (CV_a = 4.1%), intra-individual (CV_i = 44.0%) and inter-individual (CV_g = 118.6%) variations with reference change value of 122.3% were calculated. Plasminogen activator inhibitor-1 levels were elevated in patients with cardiovascular risk factors, including type 2 diabetes, pre-diabetes, smokers, obesity, hypertension, and daytime variation in procedure and blood draw.

CONCLUSION

Variation in plasma plasminogen activator inhibitor-1 levels is influenced by multiple biological and procedural characteristics. The performance of plasma plasminogen activator inhibitor-1 is consistent with biomarkers in clinical use (N-terminal pro-B-type natriuretic peptide and C-reactive protein) and its applicability is promising.

The effectiveness of age on HbA1c as a criterion for the diagnosis of diabetes in Chinese different age subjects

OBJECTIVE

To analyse the effectiveness of age on HbA1c as a criterion for the diagnosis of diabetes in Chinese different age subjects.

METHODS

This retrospective study enrolled a total of 1147 outpatients with untreated newly diagnosed diabetes (aged 18-80 years, 42·55% women) from the Fujian Province, China, and 427 age and gender-matched (control) subjects without diabetes. Receiver operating characteristic curve (ROC) was plotted to determine the performance of HbA1c against results of oral glucose tolerance test (OGTT) performed at the same time according to specific age groups. The ORs and 95%CIs between diabetes and other metabolic disorders were analysed.

RESULTS

(i) HbA1c provided an age-specific diagnosis for diabetes: there was a high diagnostic titter of HbA1c in the 18- to 39-year age group; conversely, there was a low diagnostic titter of HbA1c in the ≥70-year-old age groups. (ii) After adjusted for age, individuals with diabetes by OGTT criteria but not by WHO HbA1c criteria had an increased chance of having abnormal weight, hypertriglyceridaemia, HDL hypocholesterolaemia and insulin resistance. (iii) The diagnostic cut-off points of HbA1c for diabetes in different age groups (18-39, 40-49, 50-59, 60-69 and ≥70 years) were 6·1, 6·3, 6·4, 6·5 and 6·4, respectively. The age-specific HbA1c criteria exhibited the higher positive rate, sensitivity and lower false-negative rate when compared with WHO HbA1c criteria.

CONCLUSIONS

This provided evidence indicating that there may be drawbacks in the use of HbA1c in the diagnosis of diabetes. Thus, we proposed that the impact of introducing HbA1c for diabetes diagnosis should be considered in terms of age. Cohort studies are needed to further confirm the suitability of age-specific HbA1c criteria for the diagnosis of diabetes.