In Brief

January / February 2018   Comments

Bones, hormones and metabolism

Our skeletons are much more than the structure supporting our muscles and other tissues. They produce hormones, too. One of these is osteocalcin, which affects how we metabolize sugar and fat. When osteocalcin is released into the blood, one of its functions is to increase insulin production, which in turn reduces blood glucose levels. It can also protect us from obesity by increasing energy expenditure.

Bone cells initially produce osteocalcin in an inactive form. In a paper in the Journal of Clinical Investigation, a team led by a researcher at the Montreal Clinical Research Institute reported that an enzyme called furin, which acts like molecular scissors, is required to convert osteocalcin into its active form before it is released into the blood. They found that when the bone cells of mice lacked this enzyme, inactive osteocalcin built up. It was still released into the blood, but it led to an increase in blood glucose levels and a reduction in energy expenditure and insulin production. This discovery about the functioning of osteocalcin may someday open the door to new ways of preventing type 2 diabetes and obesity.


Tool to plot decline in cognitive performance

A simple new tool that tracks cognitive performance in adults aims to help health-care providers identify people who may be on the way to developing Alzheimer’s disease or another form of dementia. The tool, called the QuoCo (cognitive quotient), was published in CMAJ. Similar to the growth charts used in pediatrics, the QuoCo allows health-care professionals to plot the cognitive performance of any patient on the basis of age, education and score on the Mini-Mental State Examination and to track cognitive change over time. The goal would be to intervene and potentially treat an older adult who falls off the curve.

Dementia is a growing problem worldwide. Although there are no cures, potential treatments are being tested, and addressing some risk factors, such as diet and exercise, can help delay onset. The authors, from several institutions in Quebec, hope that the QuoCo will be used by health-care professionals to monitor cognitive decline in patients before irreversible damage occurs.


The deadly impact of pollution

Pollution is the largest environmental cause of disease and premature death in the world today. The Lancet commission on pollution and health has released a report addressing the full health and economic costs of air, water and soil pollution. The commission, consisting of an extensive team of international contributors, reported that pollution causes 16 per cent of all deaths globally, three times more than AIDS, tuberculosis and malaria combined. In some countries, it accounts for one in four deaths.

Pollution disproportionately kills the poor and vulnerable: 92 per cent of pollution-related deaths occur in low- and middle-income countries. Children face the highest risks because small exposures to chemicals in uteroand in early childhood can result in lifelong disease, disability, reduced learning and earning potential, and premature death.

The aim of the report, published in The Lancet, is to inform key decision-makers about the burden that pollution places on health and economic development and about available cost-effective pollution control strategies. As one of the Canadian contributors to the report commented, “Pollution, which is at the root of many diseases and disorders that plague humankind, is entirely preventable.”


Lasting effect of child abuse on the brain

For the first time, researchers have been able to see changes in neural structures in specific areas of the brains of people who experienced severe abuse as children. Earlier studies had looked at the brains of living people with magnetic resonance imaging; McGill University researchers used post-mortem samples to gain a clearer picture of the microscopic brain changes involved. They compared samples from three groups of adults: 27 people with depression who died by suicide and had a history of severe childhood abuse, 25 people with depression who died by suicide but had no history of being abused as children and 26 people who had no psychiatric illnesses or history of child abuse.

As reported in The American Journal of Psychiatry, the researchers found changes that indicated disruption in a range of neural functions in the anterior cingulate cortex, a part of the brain that plays an important role in regulating emotions and mood. The researchers believe these changes may contribute to the emergence of depressive disorders and suicidal behaviour. They plan to further explore how the brain changes they observed affect the regulation of emotions and attachment.


A baby’s gut: The secret to asthma prevention?

Pregnant moms with asthma know they may pass the condition on to their child, but a new study shows that it may be possible to prevent this. A Canadian team led by University of Alberta researchers studied 1,021 mother-infant pairs participating in the Canadian Healthy Infant Longitudinal Development Study. They compared the abundance of microbes in the feces of the babies at 3-4 months. The mothers either had or hadn’t had asthma treatment during pregnancy. It was found that Caucasian baby boys born to women with asthma, who were already known to be at the highest risk of developing asthma in early childhood, had fewer lactobacilli.

The findings of this study, published in the European Respiratory Journal, offer definitive support for the theory that escalating rates of childhood asthma worldwide over the past three decades are not caused by genetic changes. The researchers hope their work could eventually lead to a prevention approach involving modifying the set of microbes in the guts of infants at risk of developing the disease.

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