New York: Weight loss surgery can boost the level of "good" cholesterol as well as decrease the risk of heart diseases in severely obese teenage boys, says a new research. The findings showed that the levels of high-density lipoprotein (HDL) -- the good cholesterol -- increased 23 percent in the year following the weight loss surgery. Also, an increase in 12 percent was seen in the ability of HDL to remove cholesterol from artery walls to be sent to the liver and ultimately get flushed out from the body. "We already knew that weight loss surgery improves weight and cholesterol numbers. This new research shows that there are actually changes in the way HDL functions in adolescents, which may lead to a reduction in long-term cardiovascular risk," said lead author Amy S. Shah, pediatric endocrinologist and assistant professor at the Cincinnati Children's Hospital in Ohio, the US. Further, there was a decrease of 30 percent in HDL oxidation potential -- a measure of how easily HDL generates oxidants or free radicals, which can trigger unwanted inflammation. In addition, HDL became more anti-inflammatory, with a 25 percent decrease on the HDL inflammatory index. In the study, ten severely obese teenage boys, underwent vertical sleeve gastrectomy -- a type of weight loss surgery that reduces the size of the stomach. An year after surgery the teenagers showed a reduction of 111 pounds on average, and decrease in their body mass index by 32 percent. "Despite remaining obese, these young men showed improved metabolic health measured by HDL function after surgery," Shah noted. "We plan to expand our work to study girls, to look at time points sooner than one year to see how early after surgery HDL function improves, and will compare these results to other types of weight loss surgery," Shah suggested. The findings of the preliminary research was presented at the ongoing American Heart Association's Arteriosclerosis, Thrombosis and Vascular Biology | Peripheral Vascular Disease 2016 Scientific Sessions in the US.