Cardiovascular and Renal Effects of Diabetes Medications

Introduction to Diabetes Medications

• The American College of Physicians recommends GLP-1 receptor agonists as they reduce all-cause mortality and major adverse cardiovascular events compared with usual care (high certainty of evidence) 1
• The American College of Physicians, American Heart Association, and American Diabetes Association recommend strategies to reduce the risk of cardiovascular complications in patients with type 2 diabetes, including lifestyle modifications and pharmacological interventions, with high confidence of evidence 2, 3, 1

Mechanism of Action and Types of Medications

• SGLT-2 inhibitors work by preventing glucose reabsorption in the kidneys, leading to increased urinary glucose excretion 1, 4
• GLP-1 receptor agonists have a mechanism of action that mimics the natural hormone glucagon-like peptide-1 (GLP-1) and are effective in lowering fasting plasma glucose and HbA1c, with a low risk of hypoglycemia when used as monotherapy 5, 6
• The following medications have different mechanisms of action and durations of action:

Cardiovascular Benefits

• Cardioprotective effects with reduction in major adverse cardiovascular events (MACE) are associated with GLP-1 receptor agonists 1
• The LEADER trial showed a 13% relative risk reduction in cardiovascular death, non-fatal myocardial infarction, or stroke with liraglutide, indicating a reduction in major adverse cardiovascular events in patients with established cardiovascular disease 6
• Tirzepatide demonstrates greater HbA1c reductions and weight loss compared to semaglutide, with a weight loss of 20.9% at 15mg dose over 72 weeks, and is associated with lower risk of major adverse cardiovascular events compared to semaglutide 7, 1
• The European Society of Cardiology recommends tirzepatide as a safe and effective treatment option for patients with obesity, hypertension, hyperlipidemia, and prediabetes, offering substantial benefits for weight reduction and metabolic parameters 8

Weight Loss and Metabolic Benefits

• GLP-1 receptor agonists, including semaglutide, tirzepatide, exenatide, lixisenatide, and albiglutide, are effective in promoting significant weight loss, with tirzepatide achieving up to 20.9% weight loss at higher doses 5, 6, 7
• The SURMOUNT-1 trial demonstrated dose-dependent weight loss of up to 20.9% over 72 weeks with tirzepatide, substantially greater than other weight loss medications 8
• The American Diabetes Association recommends tirzepatide for superior efficacy in both HbA1c reduction and weight loss, particularly for patients requiring maximal glycemic control and weight loss 7

Hypertension Management

• The American College of Cardiology recommends considering angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers as preferred agents for hypertension management in patients with obesity 9
• The American College of Cardiology suggests avoiding β-blockers when possible as first-line treatment for hypertension in patients with obesity, as they may decrease metabolic rate, but recommends selective β-blockers with vasodilating properties (carvedilol, nebivolol) if β-blockers are required 9

Adverse Effects and Contraindications

• Common adverse effects of GLP-1 receptor agonists include gastrointestinal issues, gallbladder disorders, cardiac arrhythmia/tachycardia, and risk of thyroid C-cell tumors 6
• Long-acting GLP-1 receptor agonists have lower rates of nausea but increased incidence of injection site reactions 5
• Consider withholding GLP-1 receptor agonists for at least three half-lives before elective surgical procedures due to delayed gastric emptying and potential risk of aspiration, with contraindications including personal or family history of medullary thyroid carcinoma, Multiple Endocrine Neoplasia syndrome type 2, and known hypersensitivity to the medication or its components 6

Natural Supplements and Alternative Therapies

• Berberine is the most evidence-supported natural supplement that promotes GLP-1 secretion, although its effects are less potent than pharmaceutical GLP-1 receptor agonists 6
• Other natural products have shown potential to modulate GLP-1 expression and secretion, but the evidence is less robust compared to berberine 6