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Elevated HbA1c = CVD

Oct 20, 2020
Editor: David L. Joffe, BSPharm, CDE, FACA

Author: Alayna Marteal Wyre, Pharm. D. Candidate, South College School of Pharmacy

The study aimed to investigate whether testing HbA1c will improve CVD risk assessment.   

Cardiovascular disease (CVD) risk factors are incredibly prevalent. Risk factors such as diabetes, obesity, hypertension, and physical inactivity are all associated with cardiovascular disease. Over time, obesity rates in the population have increased, hypertension rates in the community have risen, and type 2 diabetes rates have multiplied. It can be assumed that environmental, economic, and lifestyle factors play significant roles in participants who have higher risk factors for exposure to cardiovascular disease. Efficient ways to detect early adverse effects of cardiovascular disease have been developed to predict its existence in patients with and without pre-diabetes or diabetes. Detection tests were also proposed to determine life-threatening complications of cardiovascular diseases.   

Methods and tools created to detect early developments of cardiovascular risk factors range from high-sensitivity C-reactive protein, lipoprotein-associated phospholipase A2, ankle-brachial index, and multiple imaging studies like coronary computed tomography angiography (CCTA) with coronary artery calcium scoring. Testing methods knowingly have both beneficial and non-beneficial factors; however, no single specified screening test indicates the mortality outcome prediction of cardiovascular disease risk factors. There is a need for an accurate predictor and differentiator between both fatal and nonfatal cardiovascular disease incidents.  

Glycated hemoglobin is also known as HbA1c. HbA1c is relevant mostly due to its effective ability to improve glycemic control. Since 2010, it has also been deemed a necessary diabetic testing method to uncover the disease’s presence in patients. HbA1c level measurements are essential critical components in the diabetes discovery process. In-depth research attempts to connect HbA1c with heart disease. HbA1c may play a significant role in the positive progression of the diseases effects. Combinations of testing methods to combine the pair contain scoring systems,” thorough evaluations, and other methods following national heart associations guidelines.   

The purpose of this study is to examine the beneficial capabilities of HbA1c on heart disease, along with its risks. HbA1c is renowned for its detection of blood disease-related effects amongst patients with diabetes. Although HbA1c is a specified detection method for cardiovascular disease, limitations still exist in detection for patients without diabetes. Studies conducted included one involving 38 patients with diabetes and high risks for heart disease; while other studies included over 16,000 patients with diabetes and other diabetic-related diseases. Persons that did not have diabetes and had no history of cardiovascular disease were also included within these studies for comparison purposes. Cox models measured HbA1c levels containing traces of cardiovascular disease to obtain information regarding potential risks. Risks predictability relied on the C-index and net reclassification index (NRI). The examined studies about persons without diabetes displayed connections between increased amounts of HbA1c levels and extended death terms. However, some studies’ results are inconclusive in containing examples of the said connection between HbA1c levels and cardiovascular disease.  

Within this study, results from the implementation of the QRISK3 prediction model specified that non-life-threatening cardiovascular disease took place in over 12,000 during the period of 8.9 years. Results show that 3.3% (n = 11,665) pre-diabetic participants (42.0–47.9 mmol/mol [6.0–6.4%]) and 0.7% (n = 2,573) contained misdirected and undetected forms of diabetes (≥48.0 mmol/mol [≥6.5%]). Participants screened for undetected diabetes in comparison with those unaffected, (<42.0 mmol/mol [<6.0%]), are more susceptible to contracting the cardiovascular disease with a “hazard ratio (HR) of 1.83 (95% CI 1.69–1.97) and 2.26 (95% CI 1.96–2.60). Alterations done to separate risk factors have HR of 1.11 (95% CI 1.03–1.20) and 1.20 (1.04–1.38). Combining HbA1c with the QRISK3 CVD risk prediction model (C-index 0.7392) resulted in minor increases in discrimination (C-index increase of 0.0004 [95% CI 0.0001–0.0007]). The NRI did not positively progress, and results from several testing methods and models all yielded connections.   

The investigation into pre-diabetes, diabetes, cardiovascular disease risks, and HbA1c is often refuted by determining the level of importance of their perceived risks. Many of these potential risks are not considered high cause for concern due to their varying levels connected to cardiovascular disease. Also, HbA1c level screening may not completely predict cardiovascular risks. Despite contrasting factors, HbA1c shows a significant correlation to pre-diabetes, diabetes, and cardiovascular disease risk factors. Testing of HbA1c levels does accurately predict cardiovascular risks and successfully indicate cardiovascular disease. Further research and studies should focus on compiling accurate cardiovascular risk factors to detect and diagnose the cardiovascular disease accurately. Analysis should also pinpoint other screening methods of early detection of fatal and nonfatal cardiovascular disease risks.  

Practice Pearls: 

  • There has been no single specified screening test that indicates the mortality outcome prediction of cardiovascular disease risk factors.  
  • HbA1c may play a significant role in the positive progression of the CVD’s effects.  
  • Testing of HbA1c levels does accurately predict cardiovascular risks and successfully indicate cardiovascular disease.


Reference for “Elevated HbA1c = CVD”:

Diabetes CareGlycated Hemoglobin, Prediabetes, and the Links to Cardiovascular Disease:  


Alayna Marteal Wyre, Pharm. D. Candidate, South College School of Pharmacy