Medical Bulletin 07/ March/ 2024

According to new research published in Circulation: Arrhythmia and Electrophysiology, a peer-reviewed journal of the American Heart Association, adults who reported drinking 2L or more of sugar- or artificially sweetened drinks per week had a higher risk of an irregular heart rhythm known as atrial fibrillation compared with adults who drank fewer such beverages.

Consuming sweetened drinks has been linked to Type 2 diabetes and obesity. They have also been increasingly associated with the development of atrial fibrillation, a heart rhythm disorder characterized by irregular and rapid heartbeats. The artificial sweeteners found in these drinks may disrupt normal physiological processes in the body, leading to adverse cardiovascular effects.

“Our study's findings cannot definitively conclude that one beverage poses more health risk than another due to the complexity of our diets and because some people may drink more than one type of beverage,” said lead study author Ningjian Wang, M.D., Ph.D., a researcher at the Shanghai Ninth People's Hospital and Shanghai Jiao Tong University School of Medicine in Shanghai, China. “However, based on these findings, we recommend that people reduce or even avoid artificially sweetened and sugar-sweetened beverages whenever possible. Do not take it for granted that drinking low-sugar and low-calorie artificially sweetened beverages is healthy, it may pose potential health risks.”

Researchers reviewed data from dietary questionnaires and genetic data for more than 200,000 adults not having atrial fibrillation between 2006 and 2010. During the nearly 10-year follow-up period, there were 9,362 cases of atrial fibrillation among the study participants.

The analysis revealed that consuming more than 2L per week of artificially sweetened beverages was associated with a 20% increased risk of atrial fibrillation while drinking the same amount of sugar-sweetened beverages was linked to a 10% increased risk. However, consuming 1L or less of pure fruit juice per week was associated with an 8% lower risk. Factors such as gender, age, body mass index, diabetes prevalence, and smoking status influenced the association between beverage consumption and atrial fibrillation risk.

“Although the mechanisms linking sweetened beverages and atrial fibrillation risk are still unclear, there are several possible explanations, including insulin resistance and the body’s response to different sweeteners,” Wang said. “Artificial sweeteners in food and beverages mainly include sucralose, aspartame, saccharin and acesulfame.”

“These novel findings on the relationships among atrial fibrillation risk and sugar- and artificially sweetened beverages and pure juice may prompt the development of new prevention strategies by considering decreasing sweetened drinks to help improve heart health,” concluded Wang.

Reference: Ying Sun, Bowei Yu, Yuefeng Yu, Bin Wang, Xiao Tan, Yingli Lu, Yu Wang, Kun Zhang and Ningjian Wang; Journal: Circulation Arrhythmia and Electrophysiology; DOI: 10.1161/CIRCEP.123.012145

Smoking in pregnancy likely to increase newborn behavioural issues, predicts AI

In a recent study published in The Journal Cells, Researchers from Shinshu University School of Medicine, Japan trained a deep learning system to analyse mouse behavioural experiments automatically, with the aim to investigate nicotine's effects on neurodevelopmental disorders.

For about 50 years, smoking has been recognized as a risk factor for cancer, stroke, and diabetes. Research has highlighted its harmful effects during pregnancy, including high infant mortality, preterm birth, and low birth weight. Prenatal nicotine exposure is also linked to neurodevelopmental disorders like ADHD and ASD.

Now, scientists have devised a deep learning framework to analyse mouse behaviour in nicotine exposure experiments, aiming for more accurate results. They found that prenatal nicotine exposure heightened the risk of autism spectrum and attention-deficit/hyperactivity disorders in newborns, contributing valuable insights into the link between smoking during pregnancy and neurodevelopmental disorders.

“AI tools can label the body parts of animals in a marker-less video footage and precisely estimate their poses using supervised machine learning,” explains Prof. Katsuhiko Tabuchi. “Since animal behaviours are defined as a specific arrangement of body parts over a short period of time, deep-learning toolkits like SimBA can use the pose estimations obtained with DeepLabCut to classify different types of animal behaviours.”

Researchers conducted experiments using prenatal nicotine-exposed (PNE) and control mice to identify ADHD- and ASD-like behaviours. Cliff avoidance reaction tests showed PNE mice exhibited higher impulsivity, similar to ADHD traits in humans. Using a Y-shaped maze, researchers assessed working memory in mice by counting spontaneous arm switches. PNE mice showed decreased alterations, indicating altered working memory, a trait seen in ADHD. Open-field and social-interaction experiments revealed social deficits and increased anxiety in PNE mice, features of ASD traits.

“We validated the accuracy of our behavioural analysis framework by drawing a careful comparison between the results generated by the model and behaviour assessments made by multiple human annotators, which is considered the gold standard.” highlighted Prof. Tabuchi.

Reference: Mengyun Zhou, ORCID,Wen Qiu, Nobuhiko Ohashi, Lihao Sun,Marie-Louis Wronski,Emi Kouyama-Suzuki,Yoshinori Shirai,Toru Yanagawa,Takuma Mori,Katsuhiko Tabuchi; Journal: Cell; DOI:10.3390/cells13030275

Daily steps of 9000-10,000 may reduce death and cardiovascular risks in sedentary people

According to a study published online in the Journal British Journal of Sports Medicine, every additional step up to around 10,000 steps per day reduces the risk of death and cardiovascular disease (CVD), regardless of how much remaining time is spent sedentary.

Previous studies have suggested that higher daily step counts correlate with reduced death and cardiovascular disease (CVD) rates, while prolonged sedentary behaviour is linked to increased CVD and death risks.

Led by the University of Sydney/Charles Perkins Centre, the study examined data from 72,174 individuals in the UK Biobank study. Participants wore wrist accelerometers for seven days to measure physical activity. The median daily step count for participants was 6222 steps/day, and 2200 steps/day was taken as the reference point for assessing the impact on death and CVD events of increasing step count.

Individuals sedentary for 10.5 hours/day or more were categorized as having high sedentary time, while those with less than 10.5 hours/day sedentary were considered low sedentary time. Accounting for other factors, the optimal step count to counteract high sedentary time was 9000 to 10000 steps/day. Notably, half of the benefits were observed at 4000 to 4500 steps/day in both cases.

The findings revealed that taking 9000 to 10000 steps per day could counteract high sedentary time. This reduced mortality risk by 39% and incident CVD risk by 21% over an average follow-up of 6.9 years.

“Any amount of daily steps above the referent 2200 steps/day was associated with lower mortality and incident CVD risk, for low and high sedentary time. Accruing between 9000 and 10,000 steps/day optimally lowered the risk of mortality and incident CVD among highly sedentary participants. The minimal threshold associated with substantially lower mortality and CVD risk was between 4000 and 4500 steps/day.” said the authors.

“Our prospective results provide relevant findings that can be used to augment public health messaging and inform the first generation of device-based physical activity and sedentary behaviour guidelines, which will likely include specific recommendations on daily stepping.”

Reference: Matthew N Ahmadi, F M Rezende, Ferrari, Borja Del Pozo Cruz, Min Lee, Emmanuel Stamatakis; Journal: British Journal of Sports Medicine; DOI: 10.1136/bjsports-2023-107221