Medical Bulletin 02/ August/ 2024

Here are the top medical news for the day:

The study finds that the probiotic LGG reduces the risk of necrotizing enterocolitis in preterm infants.

In a recent study published in the European Journal of Clinical Nutrition, a group of researchers assessed the strain-specific effects of LGG in preterm infants through a systematic review and meta-analysis of randomised controlled trials (RCTs) and non-RCTs.

Probiotics, which are live microorganisms offering health benefits, have been shown to reduce the risk of NEC (a serious intestinal condition in preterm infants) at Stage II or higher, as well as lower the rates of all-cause mortality, late-onset sepsis (LOS), and time to reach full feeds (TFF) among preterm infants with very low birth weight (VLBW). However, challenges remain in determining the optimal strain, duration, dosage, and safety of probiotic use.

This study followed the Cochrane methodology and the PRISMA 2020 guidelines for systematic reviews. It included both RCTs and non-RCTs published up to December 2023, focusing on preterm infants born before 37 weeks of gestation or weighing less than 2,500 grams. The intervention was central administration of LGG ATCC 53103 alone or with other probiotics, starting within the first ten days of life for at least seven days, compared to a placebo or control.

This study search yielded 1,435 potentially relevant citations. After removing 995 duplicates and excluding 331 studies that did not meet the inclusion criteria, 24 RCTs and eight non-RCTs were included in the analysis. Among the RCTs, 11 investigated single-strain LGG, while the remaining 13 examined multi-strain probiotics.

The systematic review of RCTs found that single-strain LGG significantly reduces the incidence of NEC in preterm infants but does not affect other outcomes. In contrast, multi-strain probiotics containing LGG were associated with benefits in reducing NEC, mortality, late-onset sepsis (LOS), and hospital stay duration.

References: Ananthan, A., Balasubramanian, H., Rath, C. et al. (2024) Lactobacillus rhamnosus GG as a probiotic for preterm infants: a strain specific systematic review and meta-analysis. Eur J Clin Nutr. doi: https://doi.org/10.1038/s41430-024-01474-0. https://www.nature.com/articles/s41430-024-01474-0

Study finds that tellurium contamination in foods may elevate the risk of high blood pressure.

The likelihood of developing high blood pressure (hypertension) increases with higher levels of tellurium, a contaminant transferred from mining and manufacturing activities to foods a recent study published in the journal Environment International has stated, Improved monitoring of tellurium levels in specific foods could help decrease high blood pressure in the general population.

The study was led by Nagoya University in Japan. According to Takumi Kagawa, one of the researchers involved in the study, the findings are significant as they indicate that tellurium exposure may contribute to elevated blood pressure, a significant public health concern.

In Japan, cereals and legumes, such as rice and natto (fermented soybeans), are popular dietary staples. These foods are rich in essential nutrients, including high-quality carbohydrates, vitamins, and minerals, which are beneficial for health.

However, they can also contain tellurium, a rare metalloid. The presence of tellurium in the soil often results from dust, ash, and slag released by mining and manufacturing activities. In some cases, tellurium can be absorbed from the soil into crop plants like cereals, carrots, and garlic, leading to exposure through food consumption.

The study conducted by Professor Masashi Kato, Takumi Kagawa, and their colleagues involved 2,592 Japanese adults. It found that higher levels of tellurium in urine were linked to increased blood pressure and a higher incidence of hypertension. These findings were consistent in both mice and humans.

It is found that despite raising tellurium levels in the urine, cereal/legume intake did not directly increase the risk of hypertension. Cereals/legumes may contain many diverse nutrients that can mitigate the risk of hypertension despite high levels of tellurium. However, considering that increased tellurium exposure is a latent risk factor for hypertension and foods contribute to this association, careful and continuous monitoring of tellurium levels in individual foods may be crucial.

Misawa, T., et al. (2024). Elevated level of urinary tellurium is a potential risk for increase of blood pressure in humans and mice. Environment International. doi.org/10.1016/j.envint.2024.108735.

AI Bowel Cancer Test Determines Need for Chemotherapy in Patients: Study

A study published in the Journal of Clinical Oncology reveals that a new artificial intelligence (AI) test can assess the risk of bowel cancer recurrence and potentially help patients avoid chemotherapy. Led by researchers at the University of Leeds, the test uses an AI algorithm to accurately evaluate the presence of CD3 immune cells in early-stage bowel cancer tumours. Bowel cancer, also known as colorectal cancer, affects the large bowel, including the colon and rectum, and was diagnosed in 1.9 million cases globally in 2020.

In the study, the CD3 Score test reliably showed which stage II cancers were most likely to recur within five years of surgery – and this could be used by clinicians to decide which patients may need further treatment such as chemotherapy.

Current methods for deciding which patients with early-stage bowel cancer need chemotherapy and which do not are unreliable. Many people receive chemotherapy when they don’t need it, and unfortunately some of the people who are not offered chemotherapy go on to experience cancer recurrence.

Previous studies have shown that bowel and rectal tumours with higher numbers of CD3 immune cells are less likely to recur after being removed by surgery. This is because CD3 cells can attack the cancer, helping the body tackle the disease.

They examined tissue from 868 bowel tumours at stage II and III to establish the numbers of CD3 cells within the tumours. The AI algorithm developed by the team calculated a ‘CD3 Score’ based on the number of CD3 cells in different areas of the tumour. High risk scores had lower numbers of immune cells, while low risk scores showed increased numbers of immune cells.

It is concluded that recurrence rates were reduced in both groups when patients underwent chemotherapy, but the study also showed that patients with lower numbers of immune cells were the most likely to benefit from chemotherapy.

References: Böckelman C, Engelmann BE, Kaprio T, et al: Risk of recurrence in patients with colon cancer stage II and III: A systematic review and meta-analysis of recent literature. Acta Oncol 54:5-16, 2015

Studies find a connection between cardiovascular risk factors and migraine

Having high blood pressure, specifically high diastolic blood pressure, was linked to a slightly higher odds of ever having migraine in female participants, according to a new study published in the Journal Neurology. the medical journal of the American Academy of Neurology. Diastolic pressure is when the heart is resting between beats. However, the study did not find an increased risk between other cardiovascular risk factors and migraine.

Previous research shows that migraine is linked to a higher risk of cardiovascular events such as stroke, heart disease and heart attack, but less is known about how risk factors for cardiovascular events relate to having migraine. This study looked at well-known risk factors for cardiovascular disease, such as diabetes, smoking, obesity and high cholesterol and found an increased odds of having migraine only in female participants with higher diastolic blood pressure.

The study involved 7,266 people, male and female, with a median age of 67 years, of whom 15% had previous or current migraine. All participants had physical exams and provided blood samples. They were also asked questions about migraine, including if they had ever experienced a headache with severe pain that affected their daily activities.

After adjusting for multiple cardiovascular risk factors such as physical activity, as well as education level, researchers found female participants with higher diastolic blood pressure had 16% increased odds of having migraine per standard deviation increase in diastolic blood pressure. An increase per standard deviation is a measure to compare the diastolic blood pressure with other cardiovascular risk factors. No associations were found for systolic blood pressure.

There were no associations for female participants with high cholesterol or obesity, and current smoking was associated with 28% lower odds of having migraine and diabetes with 26% lower odds of having migraine.

This study suggested that overall, migraine is not directly related to traditional risk factors for cardiovascular disease because there are people who are middle-age and older, future studies are needed in younger groups of people who are followed for longer periods of time.

References: World Health Organization. Headache disorders: https://www.who.int/news-room/fact-sheets/detail/headache-disorders.