Study investigates relationship between low-carbohydrate diets and stroke risk
Globally, 85% of cardiovascular disease deaths are due to heart attacks and strokes. This is cited by Wang et al (2022) who state that there is limited evidence on the relationship between a low-carbohydrate diet (LCD) and stroke risk. In this prospective Chinese investigation using data from the Guangzhou Biobank Cohort Study, Wang et al (2022) considered the association between low-carbohydrate diet and stroke among a population with relatively high carbohydrate intake. Almost 20 000 participants aged over 50 years without stroke history were included, with low-carbohydrate diet score calculated according to the percentage of energy from carbohydrate, protein and fat. During an average follow-up of 13 years, 1661 stroke events and deaths occurred, including 1255 ischaemic strokes. The researchers found that a moderate level of animal-based low-carbohydrate diet, but not plant-based low-carbohydrate diet, was associated with a lower risk of stroke; and that it is the animal-based protein and fat comprising the low-carbohydrate diet, rather than low-carbohydrate diet alone, that may play a key role in stroke incidence.
The study concludes that in a population consuming a high level of carbohydrate and a low level of protein and fat, a moderate level of animal-based low-carbohydrate diet, but not plant-based low-carbohydrate diet, was associated with a lower risk of stroke.
Cuffless blood pressure devices require further testing
Although cuff-based blood pressure measurement is the commonest procedure undertaken in clinical practice, Schutte (2022) notes that unreliable readings can ensue from, for example, the so-called white-coat effect, when patients and health professionals often talk during measurement, and devices not being properly calibrated.
Possible cuffless innovations include mobile phone technology with oscillometric finger pressing, and wearable ultrasound patches. But whereas makers of conventional cuff-based devices must comply with a universal standard to validate the device for accuracy, cuffless technologies vary, relying on, for instance, pulse transit time, pulse wave analyses or ultrasound. Schutte (2022) states that a ‘key question is whether these devices can accurately track the dynamic changes in blood pressure over time.’ For example, a static comparison to cuff-based or intra-arterial blood pressure using the universal standard is not good enough to claim accuracy. Further, there is the issue of ‘drift’ in accuracy post-calibration: ‘For now, there is not a protocol to validate cuffless devices.’
A consensus statement from the European Society of Hypertension makes clear that at present cuffless devices cannot be clinically recommended while fundamental questions remain about their accuracy, performance and implementation. However, with many technology companies aiming to address such questions, ‘the push for validation protocols and testing will continue to increase, racing towards the finishing line to succeed.’
Repetitive head impacts effect cognitive function
Repetitive head impacts (RHIs) and concussion are common in football, with heading independently associated with adverse profiles of brain microstructure and cognitive performance. Although the risk of long-term adverse effects from RHIs remains uncertain, early identification of cognitive dysfunction could indicate future functional disturbances.
In this American study, Ye et al (2022) investigated the impact of a 12-month heading exposure on short-term learning by studying 105 active amateur footballers: 45 women (mean age 24.9 years) and 60 men (mean age 26.7 years). Heading exposure was assessed using ‘HeadCount’ – a validated structured questionnaire – and tests of daily working memory performance were undertaken with participants using home-based computer software.
Women headed the ball less often than men (median 661 vs 1089), but whereas women in this sample exhibited better cognitive performance than men, the adverse effect of RHI on learning was specific to women. The authors suggest ‘that greater susceptibility of women to adverse effects of RHI on brain structure and function may underlie the adverse association of RHI with learning we found to be specific to women in our sample’, noting that previous studies of traumatic brain injury find women at greater risk than men for poor outcome. They suggest further studies be undertaken ‘to understand the longer-term implications of this finding …’.
COVID-19 increased public knowledge of infection prevention and control
Handwashing is one of the most effective methods for infection prevention and control and featured in government guidelines to help reduce transmission during the COVID-19 pandemic. Since the knowledge of trained professionals may differ to that of the public, Read et al (2022) assessed public understanding of infection prevention and control in England.
A face-to-face pre-lockdown survey of 2202 adults was undertaken between 24 January 2020 and 24 February 2020, and computer-aided telephone interviews of 1676 adults were undertaken between 26 February 2021 and 2 March 2021 to comply with lockdown restrictions at that time.
Compared to 2020, significantly more respondents stated correctly that infections can spread by shaking hands (86% post vs 79% pre); that microbes can be transferred through touching surfaces (90% vs 80%); that hand gel effectively removes microbes if water and soap are unavailable (94% vs 92%); and that when one coughs in a room, other people nearby in a room may become infected (90% vs 80%).
The researchers suggest that ‘future public health hygiene campaigns should capitalise on this, and emphasise that continuing hygiene behaviours, and vaccination can help prevent acquisition and illnesses with other non-COVID-19 infections, thus, reducing the strain on the National Health Service.’