Research Topic: The Cardio-Protective Benefits of Glucose-Lowering Agents

Glucose-Lowering Agents

As dietitians, it is important that we are aware of what medication our clients are on and how the medication functions in order to advocate for reviews of treatment as required. This is particularly important due to the progressive nature of chronic health diseases and the presence of associated co-morbidities. For this research topic, we are going to discuss the cardio-protective benefits of glucose-lowering agents. Let’s start off with an overview of what they actually are, read on to find out!

Overview Of Glucose-Lowering Agents

Glucose lowering agents are medications which as their name suggests, that aid in lowering blood glucose levels by targeting various organs and the response to glucose. These medications are first lines of treatment therapy for diabetes and would be administered if disease progression is well established or recommendations for promoting a healthy diet, regular exercise and weight management are not sufficient to solely manage the disease.

Examples of Glucose-Lowering Agents

  • Metformin
    • This promotes the uptake of glucose and suppresses hepatic glucose production. This therapy is often the first line of treatment for diabetes.
  • Glucagon-like peptide-1 (GLP-1)
    • Functions by improving pancreatic islet glucose sensing by delaying gastric emptying and subsequently improving satiety.
  • Sodium-glucose co-transporter-2 inhibitors (SGLT-2i)
    • Functions by blocking renal reabsorption of glucose and sodium.
  • Dipeptidyl peptidase 4 inhibitors (DPP-4i)
    • Works by improving pancreatic islet glucose sensing and increasing glucose uptake.
  • Sulfonylureas (SU)
    • Stimulates the pancreatic beta cells to increase insulin secretion.
  • Thiazolidinediones (TZD)
    • These are not commonly used however they enhance glucose uptake to skeletal muscle, suppress hepatic glucose production and decrease lipolysis in adipose tissue.

Glucose-Lowering Agents With Cardio-Protective Benefits

There are two main medication groups from the above list which have been linked to lowering the risk of cardiovascular disease (CVD), these are SGLT-2i and GLP-1.

As SGLT-2i (Empagliflozin & Canagliflozin) are known to not only inhibit the renal reabsorption of glucose but also sodium, this may be a factor in why this medication is associated with a 38% reduction in fatalities from CVD in those with and without a history of heart failure. Of additional significance is the positive impact it has on slowing the decline in estimated Glomerular Filtration Rate (eGFR) in renal disease, in clients with eGFR greater than 45.

GLP-1 use accounts for a similar reduction in CVD risk as SGLT-2i however, is an injectable medication which is subcutaneously administered and has long-lasting effects. This medication helps stimulate weight loss and is associated with low risk of hypoglycaemia. As such, prior to injectable insulin being introduced as a form of therapy, it may be worthwhile encouraging this as an earlier injectable treatment option. GLP-1 injections vary in use from daily to weekly use, with only certain types currently reimbursed in Australia under the Pharmaceutical Benefits Scheme. These include weekly injectables of Dulaglutide & Exenatide. Dietitians should be aware and outline to their clients that this medication is commonly associated with nausea within the first few weeks of use, which subsides as the duration of the treatment continues.

Cardiovascular Disease Risk With Diabetes

We know that diabetes is an independent risk factor for heart disease. It is associated with an increased risk of morbidity and mortality, with CVD recognised as the primary cause of death amongst those living with diabetes. The Framingham Heart Study found a 2-4-fold increase in the risk of myocardial infarction, congestive heart failure, peripheral arterial disease and stroke, with stronger links of CVD found for women compared to their male counterparts.

In light of these statistics, we as dietitians should be advocating for early administration of preventative measures and considering the role that medication may play. Advocating for a team-based approach to the management of these clients as well as a focus on lowering vascular risk as well as good glycaemic control should be considered at the forefront of our education as dietitians to promote better long-term health outcomes.

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