Relationship Between High Glycated Hemoglobin and Severity of Coronary Artery Disease in Type II Diabetic Patients Hospitalized With Acute Coronary Syndrome

An exploratory human study investigating the influence of type 2 diabetes on macrophage phenotype after myocardial infarction

Background

Myocardial infarction (MI) is the primary cause of death in subjects with type 2 diabetes (T2D) and their in-hospital mortality after MI is still elevated compared with those without T2D. Therefore, it is of crucial importance to identify possible mechanisms of worse clinical outcomes and mortality in T2D subjects. Monocyte/macrophage-mediated immune response plays an important role in heart remodelling to limit functional deterioration after MI. Indeed, first pro-inflammatory macrophages digest damaged tissue, then anti-inflammatory macrophages become prevalent and promote tissue repair. Here, we hypothesize that the worse clinical outcomes in patients with T2D could be the consequence of a defective or a delayed polarization of macrophages toward an anti-inflammatory phenotype.

Methods and results

In an exploratory human study, circulating monocytes from male patients with or without T2D at different time-points after MI were in vitro differentiated toward pro- or anti-inflammatory macrophages. The results of this pilot study suggest that the phenotype of circulating monocytes, as well as the pro- and anti-inflammatory macrophage polarization, or the kinetics of the pro- and anti-inflammatory polarization, is not influenced by T2D.

Conclusion

Further studies will be necessary to understand the real contribution of macrophages after MI in humans.

Protective effects of paraoxonase-1, vitamin E and selenium, and oxidative stress index on the susceptibility of low density lipoprotein to oxidation in diabetic patients with/without coronary artery disease

BACKGROUND

The oxidative modification of low density lipoprotein (LDL) is closely associated with an increased risk for coronary artery disease (CAD) in diabetic patients. The purpose of this study is to investigate the relation between serum vitamin E and selenium, paraoxonase-1 (PON1) activity, total antioxidant capacity (TAC), total oxidant status (TOS), malondialdehyde (MDA), and oxidative stress index (OSI) values with the susceptibility of LDL to oxidative modification and the possibility of CAD in diabetic patients.

METHOD

This study was designed as a case control survey of 82 diabetes patients divided into two groups including T2DM alone (as group I) and both T2DM and CAD (as group II). Fasting blood samples were taken to the assay of fasting blood glucose (FBG), HbA1c, total cholesterol (TC), TAC, TOS, MDA, OSI, vitamin E, selenium, oxidized low density lipoprotein (Ox-LDL), and activity of PON1.

RESULTS

Ox-LDL, MDA, TOS, and OSI values in groups II were significantly higher compared with group I (all with P value = 0.000). TAC, vitamin E, selenium, and PON1 activity values were significantly lower in group II compared with groups I (P value = 0.000; P value = 0.000; P value = 0.007; P value = 0.003, respectively). There were significant relationships between the amounts of TAC, TOS, OSI, and vitamin E with the amounts of PON1 activity and Ox-LDL (p < 0.05). But Ox-LDL and PON1 activity correlated weakly with together (p = 0.094).

CONCLUSION

Results of this study support the belief that oxidative stress might be an important etiologic factor which makes some diabetics more susceptible to CAD. Increased oxidative stress may be a potential therapeutic target in the prevention and management of CAD in diabetic patients.

Raised Glycated Hemoglobin (HbA1c) Level as a Risk Factor for Myocardial Infarction in Diabetic Patients: A Hospital-Based, Cross-Sectional Study in Peshawar

Background

Diabetes is a rapidly rising chronic illness in developing countries. The main objective of this research is to compare the frequency of myocardial infarction (MI) in controlled and uncontrolled diabetics in Pakistan, especially in the underprivileged district of Peshawar, and to determine raised blood glucose as a risk factor for MI.

Methodology

This cross-sectional study involving 237 diabetic patients aged 30-80 years was conducted in three major tertiary care hospitals in Peshawar, Pakistan. The inclusion criteria were diabetic patients with glycated hemoglobin (HbA1C) levels of less than 7% considered to be “controlled diabetics” and above 7% considered to be “uncontrolled diabetics.” Data were collected using structured questionnaires, past medical records, and patient history and were analyzed using SPSS software (IBM Corp., Armonk, NY, USA). The study was concluded in March 2022.

Results

The highest number of MIs occurred in diabetics with HbA1c levels of 8-9% (47.9% of all MIs). There was a significant association between increasing HbA1c levels and the incidence of MI (p = 0.002). The adjusted prevalence odds ratio for MI in uncontrolled diabetics was 6.105 (95% confidence interval = 2.42-15.43), that is, six times increased incidence of MI in patients with HbA1c of more than 7%. Furthermore, with a 1% increase in HbA1c, there was a 10% increase in the proportion of MIs.

Conclusions

From this study, it is clear that HbA1c levels of 8-9% were most significantly associated with the risk of MI in uncontrolled diabetics, and with rising levels of HbA1c, the risk of MI increased significantly. Thus, this study highlights the importance of HbA1c control in diabetic patients to prevent a heart attack.