Another way to measure obesity

Traditionally, Body Mass Index (BMI) has been used to measure obesity. Now, scientists propose a novel method that includes waist circumference (WC) in addition to BMI, providing better information about the risk of premature death for an individual. Known as A Body Shape Index (ABSI), the metric was tested on national health and nutrition data from 14,000 adults in the United States. This new parameter is based on WC adjusted for height and weight and was found to show a better correlation with death rate than does the BMI.

Death rates increased approximately exponentially with above average baseline ABSI, whereas elevated death rates were found for both high and low values of BMI and WC. The association of death rate with ABSI held even when adjusted for other known risk factors including smoking, diabetes, blood pressure, and serum cholesterol. ABSI correlation with mortality hazard held across the range of age, sex, and BMI, and for both white and black ethnicities (but not for Mexican ethnicity), and was not weakened by excluding deaths from the first 3 yr of follow-up.

Source: PloS ONE

Weight-loss drug obtains FDA approval

After 13 suspenseful years, the US Food and Drug Administration (FDA) has approved a pill that could help to fight the US obesity epidemic.

According to the FDA, Belviq (lorcaserin) can help people to lose about 3–4% of their body weight when combined with a healthy diet and exercise. The drug has been approved for use by obese people with a body mass index (BMI) greater than 30, and for a subset of overweight people (with a BMI of more than 27) who have health conditions such as high blood pressure, elevated cholesterol and type 2 diabetes.

The FDA had already rejected Arena’s first application for approval of Belviq in September 2010 because the compound seemed to produce tumours in rats and because the company could not statistically rule out an increase in the risk of heart-valve problems. Similar to fenfluramine, Belviq suppresses food cravings by mimicking the effects of serotonin in the brain, making people eat less and feel full. However, Belviq seems to activate only the serotonin 2C receptor in the brain, not the serotonin 2B receptor that is present in heart muscle.

The FDA’s turnaround this week came after Arena performed echocardiograms in nearly 8,000 people to measure heart-valve function, which revealed that there was no increase in heart-valve abnormalities among those taking the drug. The firm has agreed to run six post-marketing studies, including a long-term cardiovascular trial, and patients with congestive heart failure are advised not to take the drug.

Source: Nature (doi:10.1038/nature.2012.10923) http://www.nature.com/news/weight-loss-drug-wins-us-approval-1.10923