Stroke is killing fewer people in the U.S., a new study finds.

The study, conducted by researchers at the Johns Hopkins Bloomberg School of Public Health researchers and colleagues, found that a 24 percent decline in first-time strokes in the past 20 years. The team also found a 20 percent reduction in post-stroke deaths.

Researchers said that the decline was seen in people above 65 years of age and not in the younger population. The spike in obesity rates in the past few years has led to a large number of young adults becoming obese, which has led to an increase in risk factors for stroke. Researchers said that the U.S. might see a rise in stroke cases as these people get older.

"We can congratulate ourselves that we are doing well, but stroke is still the No. 4 cause of death in the United States," said Josef Coresh, MD, PhD, a professor of epidemiology at the Johns Hopkins Bloomberg School of Public Health, according to a news release. "This research points out the areas that need improvement. It also reminds us that there are many forces threatening to push stroke rates back up and if we don't address them head-on, our gains may be lost."

In a year, as many as 130,000 Americans die due to stroke. According to Centers for Disease Control and Prevention, around 34 percent of all stroke-related hospitalizations in 2009 were seen in people younger than 65 years of age.

The study was based on data from Atherosclerosis Risk in Communities (ARIC) study, which has data of 15,792 residents of four U.S. communities. The participants were aged between 45-64 years when the study began in the 1980s.

For the present research, study authors followed 14,357 participants who weren't diagnosed with stroke in 1987. Researchers looked at the number of stroke-related hospital visits as well as deaths between 1987 and 2011.

During the 24-year study period, seven percent had their first stroke and 58 percent of them died. The rates of stroke fell by 24 percent and the rate of death by 20 percent over the study period, USA Today reported.

The results were similar across race and gender, which is a good news because previous research on the subject had shown that stroke and death risk among African-Americans weren't improving.

Preventing stroke in younger people could help save more lives, researchers say.

The study is published in the Journal of the American Medical Association (JAMA).