News briefs

Using genetic profiles to predict obesity risk at birth

US researchers have devised a scoring system based on genetic markers that predicts an individual's inborn risk for obesity. Based upon data from the largest genome‐wide study of obesity, they applied new algorithms to integrate information from more than 2 million genetic variants affecting body mass index (BMI). The resulting score accurately predicted BMI and obesity in more than 300 000 individuals from birth to middle age. The study, published in Cell, also revealed that some people are much more susceptible to obesity than others: those scoring in the top 10% were more than 13 kg heavier on average than those in the lowest 10%, and were 25 times as likely to develop severe obesity. The impact of the score was discernable from about the age of 3 years. While the score is not a perfect predictor — some people with a genetic predisposition never become obese — the researchers contend that genetic profiles can help identify high risk individuals and help doctors recommend approaches to avoiding health risks associated with a high BMI. The microarray genetic test, costing $US50 per person tested, detects variations and mutations among millions of genetic markers. The authors believe their scoring approach will eventually be useful for predicting genetic risks for a range of health conditions, such as heart disease, breast cancer, and atrial fibrillation. Interventions might include prescribing preventive cholesterol‐lowering medication, lifestyle counselling, or using wearable technology to detect irregular heartbeat.

https://www.cell.com/cell/fulltext/S0092-8674(19)30290-9

Oxytocin could help treat alcohol use disorder

The neuropeptide oxytocin blocks increased drinking in alcohol‐dependent rats, according to a US study published in PLOS Biology. Targeting the oxytocin system, the authors noted, may provide novel pharmaceutical interventions for treating alcohol use disorder. Oxytocin can reduce consumption, withdrawal symptoms, and drug‐seeking behaviour associated with several drugs of misuse, and showed promise as a pharmacological approach to treating drug addiction. In order to understand how oxytocin achieves these effects, the investigators tested the hypothesis that oxytocin would reverse the maladaptive brain changes that develop in alcohol dependence and thereby reduce alcohol drinking in an established rat model of alcohol dependence. The authors investigated the effects of oxytocin on dependence‐induced alcohol consumption and on signaling by the inhibitory neurotransmitter γ‐aminobutyric acid (GABA) in the central nucleus of the amygdala (CeA), a key brain region in the network affected by alcohol dependence. Their results indicated that oxytocin administered systemically, intranasally, or directly into the brain reduced drinking in alcohol‐dependent but not in non‐alcohol‐dependent rats, and also blocked GABA signaling in the CeA, suggesting that oxytocin blocks increased drinking by altering CeA GABA transmission. These results provide evidence that anomalies in the oxytocin system may underlie alcohol use disorder and that targeting this system, possibly by intranasal administration of oxytocin, could be a useful therapy for people who misuse alcohol.

https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.2006421