Medical Bulletin 10/ July/ 2024

Here are the top medical news for the day:

Comparing Semaglutide vs Tirzepatide for Weight Loss in Adults with Obesity: JAMA Study

In a study published in the journal JAMA Internal Medicine, researchers analysed how weight loss differs between patients receiving tirzepatide compared with semaglutide among a clinical population of adults with overweight or obesity.

Overweight and obesity are common conditions linked to higher risks of various health issues and early death. Traditional weight loss medications have been few, poorly tolerated, and only mildly effective. However, newer drugs like semaglutide, a GLP-1 receptor agonist, and tirzepatide, a dual GLP-1/GIP agonist, have shown significant weight loss benefits in clinical trials for people with obesity, with or without type 2 diabetes (T2D). While tirzepatide has been found to cause more weight loss than semaglutide in T2D patients, direct comparisons of their effectiveness in people with overweight or obesity are still lacking.

In this cohort study, researchers used electronic health records (EHR) to assess weight outcomes for adults with overweight or obesity who received semaglutide or tirzepatide between May 2022 and September 2023. They included adults with no prior use of GLP-1 receptor agonists, who had regular care in the year before starting the medication, and an available baseline weight. Participants had a BMI of 27 or higher or a diagnosis code for overweight or obesity.

Patients were classified as having type 2 diabetes (T2D) if they had a T2D diagnosis, were prescribed insulin or DPP-4 inhibitors, or had an HbA1c level of 7.5% or higher within the past two years. The study also reviewed patient demographics, clinical comorbidities, use of other antidiabetic medications, anti-obesity medications, and history of bariatric surgery.

The results showed that patients on tirzepatide had significantly more weight loss. At 3 and 12 months, those on tirzepatide experienced greater weight reduction. Among the matched group, 81.8% on tirzepatide vs. 66.5% on semaglutide achieved at least 5% weight loss, 62.1% vs. 37.1% achieved at least 10% weight loss, and 42.3% vs. 18.1% achieved at least 15% weight loss within a year. The hazard ratios for tirzepatide compared to semaglutide were 1.76 for 5% weight loss, 2.54 for 10% weight loss, and 3.24 for 15% weight loss.

The findings revealed that individuals with overweight or obesity treated with tirzepatide were significantly more likely to achieve clinically meaningful weight loss and larger reductions in body weight compared with those treated with semaglutide. Consistent treatment effect estimates were observed in subgroups with and without T2D. Future work is needed to compare the effect of tirzepatide and semaglutide on other key end points.

Reference: Rodriguez PJ, Goodwin Cartwright BM, Gratzl S, et al. Semaglutide vs Tirzepatide for Weight Loss in Adults With Overweight or Obesity. JAMA Intern Med. Published online July 08, 2024. doi:10.1001/jamainternmed.2024.2525

Study links Healthy Lifestyle Habits to Reduced Mortality in Hypertensive Individuals

In a recent study published in the journal BMC Public Health, researchers investigated the association between cardiovascular health (CVH) and mortality in people with hypertension.

Globally, approximately 1.13 billion people suffer from hypertension, making it a leading cause of cardiovascular events and mortality. This condition significantly contributes to both morbidity and mortality worldwide.

Despite considerable advancements in the development of pharmacological treatments, effectively managing hypertension demands a comprehensive strategy. This includes not only medication but also a strong emphasis on non-pharmacological interventions. These non-drug approaches play a crucial role in hypertension management and encompass lifestyle modifications such as maintaining a healthy diet, engaging in regular physical activity, reducing alcohol consumption, and managing stress.

In this study, researchers examined the relationship between a set of eight lifestyle and environmental factors (referred to as LE8) and both cardiovascular and overall mortality in people with high blood pressure. They used data from the National Health and Nutrition Examination Survey (NHANES).

Each of the eight LE8 components was given a score from 0 to 100, and an average score was calculated for each person. Blood pressure was measured, and the average systolic (SBP) and diastolic blood pressure (DBP) were determined from three consecutive readings. Hypertension was defined as either taking blood pressure medication, self-reported high blood pressure, an average SBP of 140 mmHg or higher, or a DBP of 90 mmHg or higher.

The results revealed that participants with high cardiovascular health (CVH) scores (LE8 score of 80-100) had a lower risk of death from any cause compared to those with low (score ≤ 49) or moderate (score 50-79) CVH scores.

Those with low CVH scores had the highest risk of death. After adjusting for various factors, it was found that higher LE8 scores were linked to lower mortality risks. Specifically, each 10-point increase in the LE8 score reduced the risk of death from any cause by 8% and the risk of death from CVD by 18%.

The study showed a clear relationship between higher CVH scores and lower mortality rates, consistent across different age groups, races, body mass index (BMI) categories, sexes, and histories of diabetes or CVDs.

Reference: He L, Zhang M, Zhao Y, Li W, Zhang Y. Association between new Life’s Essential 8 and the risk of all-cause and cardiovascular mortality in patients with hypertension: a cohort study. BMC Public Health, 2024, DOI: 10.1186/s12889-024-19189-z, https://bmcpublichealth.biomedcentral.com/articles/10.1186/s12889-024-19189-z

Gut Microbe Blastocystis Associated with Reduced Body Fat, Study Finds

In a comprehensive analysis involving over 50,000 individuals worldwide, researchers discovered that carriers of Blastocystis—a single-celled organism often found in the digestive system and previously labelled as either a parasite or harmless—are associated with indicators of good cardiovascular health and reduced body fat.

This research, conducted by an international team led by investigators at Massachusetts General Hospital (MGH), a founding member of the Mass General Brigham healthcare system, has been published in the journal Cell.

In the study, researchers conducted a large-scale analysis on nearly 57,000 individuals from 32 countries, focusing on the presence of Blastocystis and its impact on cardiometabolic health. They found that Blastocystis was associated with the intake of certain food items and overall dietary patterns favouring more healthful plant-based and minimally processed foods. Interestingly, Blastocystis was rarely found in newborns, indicating it is likely acquired later in life.

Higher levels of Blastocystis were linked to better short-term markers of cardiometabolic health. For instance, individuals with higher Blastocystis levels exhibited more favourable blood sugar and lipid profiles, suggesting a potentially positive impact on cardiometabolic health beyond the benefits of a healthy diet alone. Conversely, lower levels of Blastocystis were associated with long-term outcomes such as obesity.

Additionally, in a six-month personalized diet intervention study, improvements in diet quality were linked with subsequent increases in Blastocystis prevalence and abundance. This suggested that dietary changes can influence the presence of Blastocystis, potentially contributing to better cardiometabolic health.

"Overall, our findings suggest a potentially beneficial modulating role for Blastocystis, which may help explain individualized responses to diet and differences in digestive health depending on the presence and level of Blastocystis. Also, our results indicate that Blastocystis may not be a parasite with detrimental host effects but, rather, a favourable constituent of the human gut microbiome,” said Long H. Nguyen, MD, MS, co-lead author of the study.

Reference: Piperni, E., et al. (2024) Intestinal Blastocystis is linked to healthier diets and more favorable cardiometabolic outcomes in 56,989 individuals from 32 countries. Cell. doi.org/10.1016/j.cell.2024.06.018.