Tag: 17/2/23

Fat Metabolism from Exercise Depends on Time of Day

Tired woman after exercise
Photo by Ketut Subiyanto on Pexels

Exercise at the right time of the day may increase fat metabolism, at least according to the results of a mouse study. Published in the journal PNAS, research shows that mice that did exercise in an early active phase, which corresponds to morning exercise in humans, increased their metabolism more than mice that did exercise at a time usually spent resting.

Physical activity at different times of the day can affect the body in different ways since the biological processes depend on the circadian rhythms of the cells. To ascertain the effect of exercise timing on the burning of fat, researchers at Karolinska Institutet and the University of Copenhagen studied the adipose tissue of mice after a session of high-intensity exercise performed at two points of the daily cycle, an early active phase and early rest phase (corresponding to a late morning and late evening session, respectively, in humans). The researchers studied various markers for fat metabolism and analysed which genes were active in adipose tissue after exercise.

Independent of food intake

The researchers found that physical activity at an early active phase increased the expression of genes involved in the breakdown of adipose tissue, heat production and mitochondria in the adipose tissue, indicating a higher metabolic rate. These effects were observed only in mice that exercised in the early active phase and were independent of food intake.

“Our results suggest that late morning exercise could be more effective than late evening exercise in terms of boosting the metabolism and the burning of fat, and if this is the case, they could prove of value to people who are overweight,” says Professor Juleen R. Zierath at Karolinska Institutet.

Improving the health benefits of exercise

Mice and humans share many basic physiological functions, and mice are a well-established model for human physiology and metabolism. However, there are also important differences, such as the fact that mice are nocturnal.

“The right timing seems to be important to the body’s energy balance and to improving the health benefits of exercise, but more studies are needed to draw any reliable conclusions about the relevance of our findings to humans,” says Professor Zierath.

Source: Karolinska Institutet

Certain Jobs may Increase Risk of Pregnancy Loss

Pregnant with ultrasound image
Source: Pixabay

In an analysis of 2010–2019 information on more than 1.8 million employed and non-employed pregnant women in South Korea, certain occupations were linked with higher risks of miscarriage and stillbirth.

Published in the Journal of Occupational Health, risks were calculated for three adverse outcomes: early abortive outcomes (miscarriage, ectopic pregnancy, and molar pregnancy), stillbirth, and no live birth (pregnancy with no record of live birth thereafter, which include early abortive outcomes and stillbirth).

Overall, 18.0%, 0.7%, and 39.8% of pregnancies ended in early abortive outcomes, still-births, and no live births, respectively. The risk of early abortive outcomes and stillbirths was higher in non-employed women than in employed women, while no live births were more frequent in employed women.

Women in the health and social work industry had the highest risk of no live births. Higher risks of no live births were also observed in the manufacturing, wholesale/retail trade, education, and public/social/personal service occupations. Manufacturing jobs and health/social work were associated with higher risks of early abortive outcomes compared with financial and insurance jobs.

“The good news is that the Ministry of Employment and Labor of South Korea is now revising the Industrial Accident Compensation Insurance Act to cover all the abortive outcomes in pregnant women workers. Our study contributed to the amendment of this Act, as we presented the impact of the occupational environment on adverse pregnancy outcomes,” said corresponding author Jung-won Yoon, MD, of the National Medical Center in Seoul.

Source: Wiley

Defensiveness Keeping People from Taking at-home Colorectal Cancer Stool Tests

Photo by Priscilla du Preez on Unsplash

Despite colorectal cancer being highly treatable, especially when detected early, many people do not undergo recommended screening, even with the availability of at-home stool faecal immunochemical test (FIT) kits. New research published in CANCER reveals that people who react defensively to the invitation to get screened are less likely to take part.

For the study, Nicholas Clarke, PhD, of Dublin City University in Ireland, surveyed individuals in Dublin who had been invited to participate in a FIT screening program in 2008–2012. Questionnaires were mailed in September 2015 to all individuals who were invited to participate (over two screening rounds) but had declined and a random sample of individuals who had participated. Following two reminders, questionnaires were completed by 1988 people who participated in screening and 311 who did not.

Those who did not do FIT-based screening were more likely to provide responses indicating greater defensiveness. This was apparent for all questions related to the different domains of what is called defensive information processing (DIP). The four domains of DIP include:

  • attention avoidance (reducing risk awareness by avoidance),
  • blunting (active mental disengagement through avoidance and accepted denial),
  • suppression (acknowledging others’ risk but avoiding personal inferences through self-exemption beliefs), and
  • counter-argumentation (arguing against the evidence).

“People who react defensively to the invitation to colorectal cancer screening are less likely to take part, and this seems to be due to such misconceptions that having a healthy lifestyle or having regular bowel movements means that they do not need to be screened. Similarly, some people believe testing can be delayed while they wait for a ‘better’ test (even though the current test works very well) or wait until their other health concerns are under control,” explained Dr Clarke. “Some people also react defensively because they believe cancer is always fatal, which is not true. All of these factors can result in people making a decision not to take the home-based screening test.”

Dr Clarke noted that the study’s findings indicate that even well-designed health communication campaigns and proactive screening programs may be hindered by individuals’ defensive beliefs. “The measures used in this study could be used to help identify people who may need extra support to take part in colorectal cancer screening programs worldwide,” he said. “The results suggest that screening programs need strategies to decrease procrastination and address misconceptions about colorectal cancer and screening.”

He also stressed the importance of trying to make colorectal cancer screening something that everyone routinely does when they reach middle age.

An accompanying editorial by Beverly Beth Green MD, MPH advocates for additional research to test different strategies, such as financial incentives, for decreasing DIP in participants.

Source: Wiley

Great SCOT! Repurposing Old Antipsychotics as Diabetes Treatments

Photo by Myriam Zilles on Unsplash

Researchers have found that a class of older antipsychotic drugs could be a promising new therapeutic option for people with type 2 diabetes, helping fill a need among patients who aren’t able to take other currently available treatments. The drugs interact with the metabolic enzyme succinyl CoA:3-ketoacid CoA transferase (SCOT), preventing the muscles from using ketones for fuel.

“There is a growing need to find new therapies for type 2 diabetes,” says John Ussher, professor in the Faculty of Pharmacy & Pharmaceutical Sciences and lead author of the recent study published in the journal Diabetes.

Metformin is one of the most common therapeutics for type 2 diabetes, but about 15% of patients aren’t able to take it. Iinsulin secretagogues, another commonly used drug class, isn’t as effective for later-stage patients.

“For the patients who can’t take metformin, patients with late-stage diabetes where their beta cells aren’t working as well, when you’re trying to find new therapies or new combination therapies as the disease progresses, it becomes more important to find new drug classes that target new mechanisms so then you have more options to try and lower blood sugar in those individuals,” Ussher explains.

The mechanism Ussher and his team turned their attention to is SCOT, which is an enzyme involved in the body’s process of making energy from ketones. Using computer modelling to find drugs that could potentially interact with SCOT, they landed on an older generation of antipsychotic drugs, a drug class called diphenylbutylpiperidines, or DPBP for short.

Ussher and his team had previously found that a specific drug within this class called pimozide could be repurposed to help treat diabetes, but they’ve since expanded their focus to see whether more of the DPBP class could also be useful for treating the disease.

“We’ve tested three drugs now, and they all interact with this enzyme,” says Ussher. “They all improve blood sugar control by preventing the muscle from burning ketones as a fuel source.”

“We believe this SCOT inhibition is the reason these antipsychotics might actually have a second life for repurposing as an anti-diabetic agent,” he adds.

Developing a drug is a complicated, time-consuming and expensive process. It involves clinical trials to test the safety and efficacy of the drug, and can easily cost hundreds of millions of dollars. Not to mention, it can take years to go from development in the laboratory to use in the clinic or hospital. Repurposing an existing drug may help fast-track the process, Ussher notes.

“With something that’s an older drug which we used historically in humans that we no longer use, we know what the adverse effects are, we know in general that it’s safe,” he says.

Though clinical trials are still needed, repurposing a drug allows researchers to focus specifically on the efficacy and safety of the new intended use, offering a quicker and cheaper path to a new therapy.

“As you already have safety data, it somewhat accelerates the process,” says Ussher. “And from an economic standpoint, often because a lot of these drugs being pursued for repurposing are older, they’re off patent and cheaper.”

Repurposing is effective because it capitalises on a main characteristic of most drugs, ie not being restricted to just one target in the body. As Ussher explains, most drugs actually have numerous targets they can influence.

“That’s where repurposing comes in,” he says. “Can we identify the other targets that a drug may interact with, and by identifying those other targets, can this drug serve a purpose for a different disease?”

This is what Ussher’s lab did in recognising the DPBP drug class could target SCOT activity as well as the dopamine receptors it targets in its original intended use to treat psychosis.

Knowledge of these original targets can also provide valuable context when refining and improving the repurposed drug. Since DPBP drugs were originally antipsychotics, many of their potential side-effects such as drowsiness, dizziness or fatigue arise from their effects on their original target: the dopamine receptors in the brain. Ussher’s lab is planning to try creating a modified version of the drug class that doesn’t reach the brain and has fewer potential adverse effects.

“For us, the excitement is that it looks like the entire family of these compounds interacts with this protein [SCOT] and can improve blood sugar control in type 2 diabetes.”

Source: University of Alberta