"New" Weight Loss Drugs - Our Thoughts

An estimated 70% of adults in the US struggle with excess weight and its links to associated health risks. There is a very long list of diets, and pills, and treatments, and strategies, etc., that have been around for over 50 years with varying degrees of success. So, it’s certainly understandable why the December issue of “Science” magazine called these newer blockbuster, GLP-1 weight loss drugs: “The Breakthrough of the Year”! (https://www.science.org/content/article/breakthrough-of-the-year-2023 utm_campaign=SciMag&utm_source=Twitter&utm_medium=ownedSocial#section_breakthrough)

These drugs were originally developed for diabetes and lowering blood sugar, but in recent years have mushroomed in popularity for weight management and obesity. Recent clinical trials have also found that they reduce symptoms of heart failure and the risk of heart attacks, all with minimal side effects.

While there’s a wealth of good news and positive outcomes, there are also some uncertainties to consider. One indication is that to maintain weight loss, the drugs may need to be taken indefinitely. In one study (Welding et. al. 2022. Weight regain and cardiometabolic effect after withdrawal for semaglutide. The STEP 1 trial Diabetes Obes Metab 2022; 24:1533-1564), after 68 weeks of treatment and a 17.3% weight loss, participants stopped taking the medicine and regained more than half their weight lost by week 120 with the cardiometabolic improvement decreasing. Thus, ongoing treatment may to be necessary. The ”Science” article also noted that “complications including nausea and other gastrointestinal problems lead some to abandon treatment”.

We at the Institute are always concerned with the ‘total’ body composition, so we believe an important consideration in these weight loss studies is to better understand and document the loss of muscle and bone, as well as body fat. Many individuals cannot afford to lose their lean tissue at greater than double the usual loss with weight reduction.

The challenge now for weight loss using GLP-1 agonist is quantifying the loss of both muscle and bone mass as well as fat (Moyad, 2023, Embracing the pros and cons of the new weight loss medications (Semaglutide, Tirzepatide, etc.), Urology Reports, 24:515-515).