Fatty liver disease reversed by pill in mice
In the search for a pill to combat obesity and its associated co-morbidities, researchers have found a bile acid that is capable of preventing and treating fatty liver disease in mice. In a recent study obese and diabetic mice were fed glycine-beta muricholic acid (Gly-MCA) pills. Even with a high fat diet these mice were less fat and had less insulin resistance than the control group who weren’t given Gly-MCA.
Gly-MCA is a bile acid that can inhibit the farnesoid X receptor (FXR) which maintains metabolism by sensing and regulating bile acids, fats and glucose in the body. The receptor itself plays a complex role in the pathogenesis of metabolic dysfunction in the body and that may be why Gly-MCA had such a large effect on the obesity of the mice. Usually, bacteria break down the bile acids that inhibit FXR, however these researchers found a bacteria resistant acid, Gly-MCA, that also inhibits FXR, allowing them to conduct the study. The drug itself can be consumed in pill form for humans and provides a possible avenue for the treatment of obesity, as well as fatty liver disease. However until now there has been little research into its usage, particularly with regard to toxicity. In the mice, there were no signs of systemic, hepatic or intestinal toxicity, but more work remains to be done in order to fully explore the effects of this drug in animal models and humans.
Read MoreMaternal obesity is detrimental to foetal growth
Maternal obesity results in placental overgrowth and foetal hypoxia (oxygen deficiency). These are the main findings of a a study, conducted in the University of California. Over the past decade, multiple studies have shown that maternal obesity increases morbidity and mortality for both mothers and children. Some of these studies have also suggested a link between placental pathology and maternal obesity.
This study explored the association between obesity and foetal sex on inflammation within the placental tissue on 423 normal/obese pregnant women. Obesity is associated with inflammation in a range of tissues and in this study they found that maternal obesity inflames the placenta and causes it to overgrow, whilst also potentially starving the foetus of oxygen. There was also a large amount of chronic villitis, which is an inflammatory condition that is known to cause foetal growth restriction and recurrent pregnancy loss. This finding was independent of diabetes and hypertension but differences in the condition of the placenta were seen depending on the sex of the children, with female foetuses of obese mothers having higher rates of chronic villitis. However they were unable to fully explain this disparity or correlate it with pregnancy outcomes. The study highlights the fact that mothers should aim to control their weight before becoming pregnant, as obesity can have unseen effects on their child, that may affect its future health. The study also calls for more research into the long-term effects of these findings, as this could yield valuable information about the health of individuals later in life
Read MoreIs there a need to redefine BMI cut offs for overweight and obesity?
In the 1980s, calculation of the body mass index, BMI, became an international standard for obesity measurement. It is an attempt to determine whether a person is underweight, healthy weight, overweight, or obese by quantifying the amount of tissue mass that a person has against their height. The WHO considers a BMI of 30 or more to be obese, but different countries have adopted various cut offs for each group. BMI is not without controversy, and a new study considers that for BMI thresholds to reflect similar levels of adiposity across all ages and genders, the cut offs used to identify these need to change. The study assessed whether current BMI cut offs used in the UK represent similar levels of adiposity in individuals according to age and gender. The researchers measured BMI and skin fold thicknesses of 4,316 people across England. They then used a statistical analysis called ANCOVA to observe any differences. They found that there were significant differences between different age groups and gender, for example young people had a greater BMI than older people, but had the same adiposity.
As BMI is the most frequently used proxy of obesity in large studies, it was suggested by the study authors that it should reflect changes in body composition that occur with age. The researchers also suggest that the trend observed is regularly seen by health practitioners, but they still use the current cut offs, as no new and viable ones have been proposed. They therefore provide alternative guidelines for different age groups, as outlined in Table 1, explaining this in terms of the amount of muscle (which weighs slightly more than fat) that a young male is likely to have, when compared to an older male counterpart. It will be interesting to see whether changes are made to the current BMI cut offs as a result of this study.
Read MoreBone structure at risk in obese children
Children under the age of 18 with increased fat mass have compromised bone growth. A recent literature review has found that fat deposited within muscle may have an effect on how bones grow. Joseph Kindler, the study’s lead author, gathered existing research into the effects of muscle and fat mass on bone geometry (the spatial distribution of bone and how dense bone materials are in the body). It is already known that fatter children tend to have more muscle mass, as the body needs to move larger amounts of weight, so needs to be stronger. This study found that increased muscle mass in children will subsequently increase bone growth.
However, the study also discovered that the fat found in obesity is deposited within muscles. The effect of this fat is still being investigated; however it is clear that there is a connection with bone growth, which is possibly negative. A reduction in strength, such as the one seen, could lead to an increased risk of fractures in these children and adolescents. Overall the paper stresses that whilst an increased muscle mass is most likely beneficial for bone geometry, an increased muscle mass accompanied with an increased fat mass may actually be harmful; more research needs to be conducted into this area in order to fully understand the complex mechanisms of bone growth and fat influence.
Read MoreChanges in gut microbiome burn fewer calories
Many anti-psychotic drugs induce weight gain. A new study conducted at the University of Iowa has concluded this may be due to alteration of the gut microbiome, changes in which have been associated with obesity. The researchers analysed the effects of the drug risperidone, an anti-psychotic drug that is commonly prescribed to adults and children as treatment for disorders including autism, bipolar, and schizophrenia. The researchers were building on previous knowledge that showed that risperidone increases weight in humans, however they did not know what the mechanism was, until now.
Using mouse models, they were able to measure changes in the gut microbiome that caused a reduction in resting metabolic rate. This shift eventually led to obesity in the risperidone mice, whereas the control mice had normal weight gain with age. The measurements were taken using a total calorimetry machine, which accurately measures energy intake, oxygen consumption, carbon dioxide output and heat production, that allowed the researchers to accurately determine the total energy changes of the mice and their metabolic rates. They were also able to repeat the results by faecal transplants from the risperidone mice to the control mice, proving that the weight changes were due to a microbiome change in the drug-using mice. The study as a whole suggests that manipulation of gut bacteria, and specifically the resting metabolic rate, may prove beneficial for patients undergoing risperidone treatment, but also for those suffering from obesity in general.
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