Tag: 27/1/21

Categories : Cardiovascular Disease ExerciseTags :

Large Study Casts Doubt on “Fat but Fit”

On By ModernMedia

New Spanish research casts doubt on the “fat but fit” paradox, where it is thought that physical fitness is enough to eliminate cardiovascular disease (CVD) risk.

Overweight and obesity is a worldwide problem that is greatly contributing to the burden of noncommunicable diseases, including CVD. A high body mass index (BMI) is strongly associated with CVD risk factors, such as hypercholesterolaemia, hypertension and diabetes. The cardiovascular complications arising from overweight and obesity are driven by processes such as inflammation, insulin resistance, endothelial dysfunction, coronary calcification. Some evidence suggested that physical activity was cardioprotective, partly or completely eliminating the CVD risk from disease – the “fat but fit” paradox.

A recent meta-analysis showed that cardiovascular fitness was a better predictor of cardiovascular disease over overweight/obesity, suggesting that perhaps public health programmes should emphasise fitness over control of body weight. To this end, the researchers sought to confirm if the “fat but fit” paradox was real.

The researchers gathered data from workers’ health insurance, with participants aged 18-64 grouped into normal weight, overweight and obesity by BMI, and into regularly active ( >150 min moderate physical activity or equivalent per week), insufficiently active (less than regularly active) and inactive (no physical activity at all). They were further separated by age, sex, smoking status and residential address.

Approximately 42%, 41%, and 18% of participants had normal weight, overweight, or obesity, respectively; 63.5%, 12.3%, and 24.2% were inactive, insufficiently active, and regularly active; and 30%, 15%, and 3% had hypercholesterolaemia, hypertension, and diabetes.

However, the protective effect of physical activity was far less than the excess risk from overweight/obesity. So much so that even regularly active obese participants had two to five-fold risk increases over their inactive but normal weight peers in the risk factors.

The protective effect of physical activity in overweight/obesity remains controversial. Shortcomings of the study were that they did not control for diet, and only accounted for self-reported leisure time activities. However, the large study size, with over 500 000 participants, should put paid to the theory that a physically active lifestyle can completely eliminate the deleterious effects of overweight/obesity.

The researchers concluded that, “weight loss per se should remain a primary target for health policies aimed at reducing CVD risk in people with overweight/obesity.”

Journal article source: European Journal of Protective Cardiology

Journal information: Pedro L Valenzuela, et al., Joint association of physical activity and body mass index with cardiovascular risk: a nationwide population-based cross-sectional study, European Journal of Preventive Cardiology, 2021;, zwaa151, https://doi.org/10.1093/eurjpc/zwaa151

Categories : Mental HealthTags :

LSD Shown to Heighten Sociability in Mice

On By ModernMedia

Scientists at McGill University have discovered that mice micro-dosed with LSD have an increased level of sociability, pointing to a mechanism by which the drug can influence behaviour at these low concentrations.

Lysergic acid diethylamide (LSD) was discovered by accident while developing stimulants, and was first used to study psychotic states. There was initially great interest in and use of LSD for psychiatric treatment, but the harmful and lasting side-effects resulted in it steadily being outlawed. However, recent anecdotal evidence of individuals self-administering micro-doses of LSD to improve cognitive functioning have helped spur renewed interest in the famous drug.To investigate the ways LSD might be working on the brain, the McGill University researchers dosed mice with low levels of LSD over seven days, and observed a measurable increase in sociability.

This is useful as a main outcome of the study is a mechanism that describes the increased feelings of empathy and awareness that users of LSD describe.

Co-lead author Prof Nahum Sonenberg at McGill University, world renowned expert in the molecular biology of diseases, explained: “The fact that LSD binds the 5-HT2A receptor was previously known. The novelty of this research is to have identified that the prosocial effects of LSD activate the 5-HT2 receptors, which in-turn activate the excitatory synapses of the AMPA receptor as well as the protein complex mTORC1, which has been demonstrated to be dysregulated in diseases with social deficits such as autism spectrum disorder.

“Their next research goal is treating mutant mice with behavioural deficits mimicking human psychological pathologies, and to find out if micro-dosed LSD or some derivative could be a safe and effective therapeutic option.

“Social interaction is a fundamental characteristic of human behaviour,” noted co-lead author Dr Gabriella Gobbi, Professor in the Department of Psychiatry at McGill and psychiatrist at the McGill University Health Centre. “These hallucinogenic compounds, which, at low doses, are able to increase sociability may help to better understand the pharmacology and neurobiology of social behavior and, ultimately, to develop and discover novel and safer drugs for mental disorders.”

Source: Medical Xpress

Journal information: Danilo De Gregorio et al, Lysergic acid diethylamide (LSD) promotes social behavior through mTORC1 in the excitatory neurotransmission, Proceedings of the National Academy of Sciences (2021). DOI: 10.1073/pnas.2020705118

Categories : Allergies PaediatricsTags :

Black American Children Have Higher Rates of Shellfish and Fish Allergies

On By ModernMedia

A study from Rush University Medical Center in the US has shown that black children in that country are more likely to have allergies to fish and shellfish than white children.

Some 8% of children in the US suffer from food allergies, which can result in signs and symptoms such as hives, breathing and digestive problems or anaphylaxis, sometimes severe enough to be life-threatening.

Lead author Dr Mahboobeh Mahdavinia at Rush University Medical Center, explained: “Food allergy is a common condition in the U.S., and we know from our previous research that there are important differences between African-American and white children with food allergy, but there is so much we need to know to be able to help our patients from minority groups.”

The study found that the black children were more likely to have an allergy to shellfish and fin fish, and also higher odds of having a wheat allergy, compared to the white children. The researchers believe the reason for this is environmental and socioeconomic: in the US, black children are more likely to be exposed to cockroaches than white children due to the increased probability of living in more socioeconomically deprived areas.

Tropomyosin, a protein found in two common household allergens, dust mite and cockroaches, share 80% of amino acid sequencing with shellfish. Some 72-98% of individuals allergic to prawns have an immunoglobin E response to tropomyosin. It has also been found in fin fish. Although the exact mechanism by which the allergy is established is not known, it provides evidence as to the importance of reducing the exposure of black children to cockroaches.

The study also showed that shellfish allergy was associated with increased asthma risk in black children. “This information can help us care for not only a child’s food allergy, but all of their allergic diseases, including asthma, allergic rhinitis and atopic dermatitis,” said co-author Susan Fox, PA-C, MMS, an allergy and immunology physician assistant at Rush University Medical Center.

The increased risk of asthma combined with food allergies can prove a lethal combination for children. “A major concern is that there is a higher prevalence of asthma in African-American children with food allergies when compared with white children with food allergies. Approximately 70% of fatal food anaphylaxis is accompanied by asthma. African-American children are at a two- to threefold risk of fatal anaphylaxis compared to white children,” Dr Mahdavinia said. “By knowing this information, it can identify [our] most at risk patients.

“We need to conduct further research to identify food allergies and food sensitivities among all races and ethnicities so we can develop culturally-sensitive and effective educational programs to improve food allergy outcomes for all children,” Dr Mahdavinia concluded.

Source: News-Medical.Net

Categories : Ageing Cardiovascular DiseaseTags :

New Study Has Good and Bad News on TIAs

On By ModernMedia

There is both good and news on transient ischaemic attacks (TIAs) from a more than six-decade long study: TIAs are indeed harbingers of strokes, but also the incidence of post-TIA strokes has been falling over the decades.

A TIA is defined as a passing episode of neurologic dysfunction due to the focal brain, spinal cord, or retinal ischaemia, without acute infarction or tissue injury. The results were derived from the Framingham Heart Study had 14 059 participants and ran for over six decades, allowing for a more-complete picture of strokes that happen after a TIA. Of the participants, 435 had a TIA; these were compared against a second group of 2175 participants who did not have a TIA.

Even after accounting for other risk factors such as hypertension or diabetes, people who had experienced a TIA had a 4.5 to five times greater chance of a stroke. Study lead author Vasileios-Arsenios Lioutas, MD, said that the results show a need for intensive follow-up of TIA : “According to our findings, people continue to have a high risk of stroke for a sustained time after they’ve had a TIA. Therefore, one shouldn’t think that the high-risk period is just in the first 90 days after the attack and then one can relax. It seems these patients should be followed closely over time, keeping in mind that they are at risk for stroke and paying close attention to controlling their cardiovascular risk factors.”

The 66 years of study data was broken into three epochs. One- and five-year risks of post-TIA stroke in the 2000-2017 epoch were 7.6% and 16.1%, compared to 23.9% and 35.5% during the earliest epoch, from 1948 to 1985.

Sudha Seshadri, MD, professor of neurology at The University of Texas Health Science Center at San Antonio, said: “We examined 66 years of follow-up from Framingham participants, which allowed us to study trends over time. We can see that starting in the very early years of the Framingham study, the 1950s, moving on to the most recent times, the risk of subsequent stroke went down a lot.”

Source: News-Medical.Net

Journal information: Lioutas, V-A., et al. (2021) Incidence of Transient Ischemic Attack and Association With Long-term Risk of Stroke. JAMA.doi.org/10.1001/jama.2020.25071.