Patients who stopped taking GLP-1 drugs for two years faced a 22 percent increase in cardiovascular events compared with those who continued treatment, according to a study of more than 600,000 veterans published this month by researchers at Washington University in St. Louis. The findings, reported by CNBC on March 18, transform the calculus of a drug class that 15 million Americans now use. [1] [2]

The study tracked patients with type 2 diabetes who were prescribed GLP-1 receptor agonists between 2010 and 2023. Those who stayed on the drugs continuously for three years saw an 18 percent reduction in major adverse cardiovascular events: heart attack, stroke, and death. Those who stopped saw the benefits erode on a gradient. Six months off raised risk by 4 percent. One year off raised it by 14 percent. Two years off raised it by 22 percent. The erosion was not merely a return to baseline. It exceeded it. [1] [3]

The implication is stark. GLP-1 drugs are not a course of treatment with a defined endpoint. They are, for cardiovascular purposes, a permanent intervention. Stopping them is not neutral. It is a medical event with measurable risk. The lead researcher, Dr. Ziyad Al-Aly, told Reuters that clinicians should "treat discontinuation as seriously as they would treat initiation." [3] [4]

For the estimated 3 to 5 million Americans who have started and stopped GLP-1 drugs due to cost, insurance changes, or shortage-related supply disruptions, the study introduces a new category of concern. The on-again, off-again pattern that characterized 2024 and early 2025 supply constraints may have produced cardiovascular harm that will take years to quantify. [2]

The pharmaceutical industry has not been slow to notice. Novo Nordisk's share price rose 2.4 percent on the day the study was published. A drug that patients cannot safely stop is a drug with a lifetime revenue curve. The market heard what the study said. [1]

-- NORA WHITFIELD, Chicago