Medical Bulletin 21/ May/ 2024

Researchers estimate that about 1% of the global population has pulmonary hypertension — a disease caused by high blood pressure in the blood vessels that deliver oxygen to the lungs.

Now, according to research presented at the ATS 2024 International Conference, the use of hormone replacement therapy (HRT) may be associated with improved pulmonary hypertension in women.

Hormone replacement therapy (HRT) may offer potential benefits for women with pulmonary hypertension. Estrogen, a key hormone in HRT, has been found to have vasodilatory effects, meaning it can help relax and widen blood vessels, improving blood flow and reducing the strain on the heart. Additionally, HRT may help address symptoms of menopause that can exacerbate the condition, such as fatigue and reduced exercise capacity.

In this study, researchers recruited 742 female participants and classified those with pulmonary hypertension into the five groups established by the World Symposium on Pulmonary Hypertension:

Group 1: Pulmonary arterial hypertension

Group 2: Pulmonary hypertension caused by left heart disease

Group 3: Pulmonary hypertension caused by lung disease

Group 4: Pulmonary hypertension from chronic blood clots in the lungs

Group 5: Pulmonary hypertension from unknown causes

The impact of both exogenous and endogenous hormone exposure on pulmonary hypertension across these groups were examined.

Upon analysis, researchers discovered that average pulmonary arterial pressure decreased with a greater lifetime duration of menstruation across all pulmonary hypertension groups. They also found that hormone replacement therapy (HRT) was associated with lower mean pulmonary artery pressure, higher right ventricular fractional shortening, and improved right ventricular ejection fraction.

Specifically, those in pulmonary hypertension Group 1 showed lower mean pulmonary artery pressure, reduced pulmonary vascular resistance, and higher right ventricular ejection fraction when exposed to HRT.

“Our preliminary data indicates that hormone replacement therapy (HRT) improves mean pulmonary arterial pressure, pulmonary vascular resistance, right ventricular ejection fraction, and right ventricular fractional shortening in women with pulmonary hypertension. No differences were observed in healthy controls or with increased lifetime duration of menses. These findings support the hypothesis that hormones may be protective, especially notable in Group 1 pulmonary hypertension. Further studies are needed to explore this,” said Audriana Hurbon, assistant clinical professor in the Department of Medicine at The University of Arizona College of Medicine Tucson and corresponding author of the study.

Reference: A. Hurbon, G.J. Beck, S.C. Erzurum, R.P. Frantz, G. Grunig, P.M. Hassoun, A. Hemnes, N. Hill, E. Horn, C. Jellis, B. Larive, J. Leopold, M. Park, E.B. Rosenzweig, F.P. Rischard, and PVDOMICS Study Group. The Impact of Reproductive History on Pulmonary Hypertension: Insights From the Pvdomics Study (abstract). Am J Respir Crit Care Med 2024;209:A2748.

In a recent study published in the Journal of Clinical Endocrinology & Metabolism, researchers evaluated body fat percentage thresholds to define overweight and obesity, examining their correlation with metabolic syndrome.

Typically, BMI is used to define obesity and overweight, but it is an imprecise measure of body fat percentage (%BF). Modern technologies have improved body fat percentage estimation, but outcome-based body fat percentage thresholds are needed to guide patient health effectively.

Previous correlations of body fat percentage with health risks using BMI have been imprecise due to factors like sex, age, and fitness. Obesity-related diseases are linked to excess adiposity, yet current weight recommendations often rely on generalized mortality statistics. New methods like multifrequency bioelectrical impedance (MF-BIA) offer more accurate body fat percentage estimation and could improve management of obesity-related diseases compared to BMI.

In the study, correlational analyses were conducted using data from the National Health and Nutrition Examination Survey (NHANES) to evaluate body fat percentage thresholds for defining overweight and obesity. The sample consisted of 16,918 individuals aged 18 to 85, with data collected between 1999 and 2018, excluding periods without dual-energy x-ray absorptiometry (DXA) measurements. Data included demographics, laboratory measures, body measures, and whole-body DXA assessments.

The results showed that among overweight individuals (BMI >25 kg/m²), 5% had metabolic syndrome, while among obese individuals (BMI ≥30 kg/m²), this proportion increased to 35%. New body fat percentage thresholds were established: 25% for overweight and 30% for obesity in males, and 36% for overweight and 42% for obesity in females. Using these thresholds, a significant portion of both men and women were classified as overweight or obese.

The study emphasized the poor predictive value of BMI due to variability in body fat percentage at any given BMI, highlighting the limitations of BMI in assessing adiposity and associated health risks, particularly across genders.

The findings suggested that body fat percentage thresholds are superior to BMI in predicting obesity-related health issues. It recommends using direct adiposity measurements in clinical practice, proposing thresholds of 25% BF for identifying overweight in men and 36% BF in women.

Reference: Defining overweight and obesity by percent body fat instead of body mass index. Potter, A.D., Chin, G.C., Looney, D.P., Friedl, K.E. The Journal of Clinical Endocrinology & Metabolism (2024). DOI: 10.1210/clinem/dgae341, https://academic.oup.com/jcem/advance-article/doi/10.1210/clinem/dgae341/7673666

A national poll conducted by the University of Michigan Health C.S. Mott Children’s Hospital National Poll on Children’s Health explored the prevalence of caffeine consumption among adolescents.

According to the findings, based on responses from 1,095 parents of teens, one in four parents reported that their teenage children consume caffeine daily or almost every day. Notably, soda emerged as the top caffeinated product of choice among teens, followed by tea and coffee, while energy drinks were consumed less frequently.

Caffeine, a stimulant that affects the brain and nervous system, can pose various health risks, particularly in young individuals whose brains are still developing. Excessive caffeine intake among teens has been linked to adverse effects on mood, sleep, and academic performance, alongside other potential side effects. Furthermore, prolonged consumption may lead to dependency, akin to other drugs.

The FDA suggests that healthy adults can have up to 400 milligrams of caffeine daily without risks. The American Academy of Pediatrics advises against caffeine for kids, while other experts recommend a limit of 100 milligrams daily for teens.

The study revealed insights into the driving factors behind teen caffeine consumption. While some teens opt for caffeinated products due to peer influence or to stay awake during school hours, a significant portion indulges in them for the taste rather than the stimulant effect. However, many parents may not be fully aware of their children's caffeine intake, as evidenced by the findings.

The study also highlighted that the most common setting for teen caffeine consumption is at home, followed by dining out, providing an opportunity for parental intervention. With adequate awareness and monitoring, parents can help their teens reduce their caffeine intake and mitigate associated health risks. Notably, experts recommend familiarizing oneself with recommended caffeine limits, monitoring caffeine levels in teens' favourite beverages, and watching for signs of overconsumption.

“Our report suggests parents may not always be aware of how much they should be limiting caffeine consumption for teens. Parents should check labels on drinks and snacks to see how much caffeine they have. If teens have trouble sleeping or seem jittery, they might be having too much caffeine. It's recommended for parents to talk to their teens about caffeine intake and make them understand the potentially harmful effect they have on health,” said Susan Woolford, poll co-director and Mott paediatrician.

Reference: Woolford SJ, Schultz SL, Gebremariam A, Ewing L, Freed GL, Clark SJ. Parents asleep on teen caffeine consumption? C.S. Mott Children's Hospital National Poll on Children's Health, University of Michigan. Vol 45, Issue 3, May 2024. Available at: https://mottpoll.org/reports/parents-asleep-teen-caffeine-consumption.