Thursday Shorts: GLP-1, smartwatches, discrimination, fluoride and breast cancer screening
April 17, 2025
A. Oral GLP-1 lowers cardiac risk
Researchers reported in this week’s New England Journal that oral semaglutide (Rybelsus) was almost as effective as injectable semaglutide (Ozempic) at lowering the risk of cardiac events in people with diabetes and known heart or kidney disease. This was a large, high-quality randomized trial with 9,650 participants. The researchers found over a five-year follow up period those on oral semaglutide had 14% fewer cardiovascular events than those who were treated with placebo. Injectable semaglutide was associated with a 26% decrease in major cardiovascular events in those with diabetes. Only slightly more on the oral semaglutide (5%) reported gastrointestinal side effects compared to those on placebo (4.4%).
Oral GLP-1 medications might gain wider patient acceptance than injections. However, the oral medication is currently priced similarly to the injectable medicine, so a transition to oral medication would not lower employer pharmacy claims costs. Existing studies are conflicting as to whether adherence to a weekly shot is better than adherence to a daily pill.
B. Smartwatch heart monitoring can predict cardiac risk
Researchers correlated data from 7,000 users of the Fitbit device with electronic medical records and found that those who had more heart rate elevation with exercise were more likely to have risk factors for cardiovascular disease. The study was too short to detect increased incidence of heart attacks or strokes. Those in the top quartile of heart rate elevation were twice as likely to have diabetes, 1.7 times as likely to have heart failure, 1.6 times more likely to have high blood pressure, and 1.4 times more likely to have plaque in their coronary arteries.
I have some personal experience with the clinical value of wearables. I used my Apple Watch in 2019 to document my especially slow heart rate, which helped convince emergency department clinicians to monitor me long enough that I was diagnosed with sick sinus syndrome (and got a pacemaker). Wearables can help assess risk and will eventually be used for much more than counting steps.
C. Discrimination associated with anxiety and depression
Source: Wang, et al JAMA Network Open March 28, 2025
Researchers used data from a nationally representative sample of almost 30,000 survey respondents to correlate results of a validated survey of discrimination with reported anxiety and depression. No surprise, they found that those who reported more discrimination were more likely to also test positive on screening tests for anxiety and depression. All the more reason to eliminate discrimination.
D. Discontinuing fluoride in water makes regular dental care even more important
Utah recently passed a law prohibiting fluoridation of public water supplies last month, and Health and Human Services Secretary Robert F. Kennedy Jr. has suggested that he wants other states to take similar action. Very high doses of fluoride have been associated with cognitive decline, but doses used in public water supply have proven quite safe, and fluoridation is associated with substantial reductions in dental cavities.
Fluoridation is regarded as an important public health triumph, and the rate of childhood cavities has increased when cities have stopped fluoride treatment in the past. Here’s a link to a scientific review of this issue from Katelyn Jetelina, the writer of Your Local Epidemiologist. Brushing teeth with toothpaste containing fluoride and having regular dental cleanings can protect teeth from cavities. Dental sealants have also dramatically reduced childhood cavities, although children of lower income families are 20% less likely to get sealants and twice as likely to have untreated dental cavities. An increase in dental disease could be a special challenge in rural areas that have poor access to dental care.
E. Wellness visits boost mammography rates
Source: Dixit, et al Annals of Internal Medicine April, 2025
Researchers used the National Health Interview survey data (2021) to assess the likelihood that American women had a mammogram in the last year or two years. They found a high correlation with women who had a preventive visit, and White women had lower mammography rates than Black women. Those with higher education were also more likely to have had recent mammograms. This segmentation could help companies plan cancer screening programs. Current US Preventive Services Task Force guidelines recommend mammography every other year from ages 40 to 75. Breast and colorectal cancer screening rates declined during the pandemic but have rebounded since.