Medical Bulletin 29/January/2026 - Video

Here are the top medical news for today:

Exercise Key to Regaining Fitness After GLP-1-Assisted Weight Reduction: Study

A new study published in Sports Medicine shows that exercise—not weight-loss drugs alone—is the key to improving physical fitness after weight loss in people with obesity.

Obesity affects over 650 million adults worldwide and is often linked to poor mobility, low stamina, and difficulty performing everyday tasks like climbing stairs. While weight-loss diets and medications such as GLP-1 receptor agonists (including liraglutide) can help people lose weight, researchers wanted to know whether weight loss by itself actually improves physical fitness.

In this study, adults with obesity first followed a very low-calorie diet and lost at least 5% of their body weight. They were then followed for one year and divided into four groups: no treatment, exercise only, liraglutide only, or a combination of exercise and liraglutide.

The results were clear. Participants who exercised—either alone or with liraglutide—showed the biggest improvements in fitness and mobility. They climbed stairs faster, had better heart and lung fitness, and maintained muscle strength. In contrast, those who took liraglutide without exercise did not see meaningful improvements in physical performance, even though they maintained weight loss.

Importantly, the study found that more exercise led to better results. Even small increases in weekly physical activity improved stamina and mobility.

Muscle strength was preserved across all groups, but muscle quality declined in participants who neither exercised nor took medication.

Overall, the findings highlight that exercise plays a central role in long-term health after weight loss. While GLP-1 drugs help with weight control, combining them with structured exercise delivers the greatest benefits for physical fitness, independence, and quality of life.

REFERENCE: Jensen, S.B.K., Fiorenza, M., Juhl, C.R. et al. Physical Fitness with Exercise and GLP-1 Receptor Agonist Treatment Alone or Combined After Diet-Induced Weight Loss: A Secondary Analysis of a Randomized Controlled Trial in Adults with Obesity. Sports Med (2026). DOI: 10.1007/s40279-025-02386-0, https://link.springer.com/article/10.1007/s40279-025-02386-0

Menopause Linked to Reduced Brain Volume and Higher Anxiety Symptoms, Study Finds

A new study from the University of Cambridge has found that menopause is linked to changes in the brain, along with higher levels of anxiety, depression, and sleep problems. The research, published in Psychological Medicine, also suggests that hormone replacement therapy (HRT) does not prevent most of these brain changes, although it may help slow down reaction-time decline.

Menopause usually occurs between the ages of 45 and 55, when hormone levels drop and periods stop. Many women experience hot flushes, low mood, poor sleep, and mental health challenges during this time. To better understand how menopause affects the brain, researchers analysed data from nearly 125,000 women in the UK Biobank.

Women were grouped as pre-menopausal, post-menopausal without HRT, or post-menopausal with HRT. Some participants completed memory and reaction-time tests, and around 11,000 also had brain scans.

The study found that post-menopausal women were more likely to report anxiety, depression, insomnia, and fatigue. Those on HRT reported feeling the most tired, even though they slept about the same amount as other women. Importantly, higher anxiety and depression in the HRT group were already present before menopause.

Brain scans showed reduced grey matter in key areas involved in memory, emotions, and decision-making, including regions linked to Alzheimer’s disease. These changes were seen in post-menopausal women regardless of HRT use.

While HRT did not protect brain structure or mood, it helped slow the decline in reaction speed. The researchers stress the importance of supporting women’s mental health during menopause and maintaining a healthy lifestyle through exercise and balanced nutrition.

REFERENCE: Zühlsdorff, K., et al. (2026) Emotional and cognitive effects of menopause and hormone replacement therapy. Psychological Medicine. DOI: 10.1017/S0033291725102845. https://www.cambridge.org/core/journals/psychological-medicine/article/emotional-and-cognitive-effects-of-menopause-and-hormone-replacement-therapy/E9D94A6EB0B8A3C03113A93D34A99FD0

Starting Age of Smoking Matters as Much as Quantity, Study Finds

A large new study from South Korea shows that starting smoking at a young age significantly raises the risk of heart attacks, strokes, and early death, even when accounting for total lifetime cigarette exposure. People who began smoking before age 20 had the highest risks, suggesting that adolescence may be a particularly vulnerable period for long-term cardiovascular harm.

The study analyzed over 9 million adults aged 20 and older who participated in a national health screening in 2009. None had a history of heart attack, stroke, or severe kidney disease at the start. Participants reported their smoking habits, including age at initiation, current status, and cumulative exposure measured in pack-years. Researchers also considered other factors like blood pressure, cholesterol, diabetes, physical activity, alcohol use, and socioeconomic status.

Over roughly nine years of follow-up, smokers consistently showed higher risks than non-smokers. Early starters with heavy smoking histories (20+ pack-years) had more than double the risk of heart attack (HR 2.43), higher risk of stroke (HR 1.78), combined stroke or heart attack (HR 2.00), and increased all-cause mortality (HR 1.82). Even smokers with similar pack-years who started later had lower risks, highlighting that early smoking amplifies the harm of cigarettes.

The study also found a clear dose-response relationship: the earlier someone starts, the higher their cardiovascular risk, independent of total smoking exposure. These trends held across men and women, people with different metabolic health, and various smoking intensity levels.

Although the research relied on self-reported data and primarily involved Asian men, its huge sample size and long follow-up make the findings compelling.

From a public health perspective, the study emphasizes that preventing young people from starting smoking—especially before age 20—could dramatically reduce heart disease, stroke, and premature death. This adds to existing evidence that adolescence is a critical window for preventing long-term health damage from smoking.

REFERENCE: Koh, J.H., Han, K., Kim, M., Cho, J.M., Jung, S., Lee, S., Kim, Y., Cho, S., Huh, H., Kim, S.G., Kang, E., Joo, K.W., Kim, D.K., Park, S. (2026). Early age at smoking initiation is associated with elevated cardiovascular disease and mortality risk in a nationwide population-based cohort. Scientific Reports, 16, 3063, https://www.nature.com/articles/s41598-025-88253-4