Cigarette smoking rose slightly on a national basis for the first time in almost 15 years, dashing health officials' hopes that the U.S. smoking rate had moved permanently below 20 percent.

According to a 2008 national survey by the U.S. Centers for Disease Control and Prevention, 20.6 percent of U.S. adults said they smoked. That's up slightly from the year before, when just 19.8 percent said they were smokers. It also is the first increase in adult smoking since 1994, experts noted.

Also on Thursday, the CDC released state-by-state results on smoking from a different survey, conducted by telephone, of more than 400,000 adults, which found  that Indiana had the second highest smoking rate in the nation.

About 26.1 percent of Indiana adults are smokers, trailing only West Virginia, with a rate of 26.6 percent. Kentucky was next with a rate of 25.3 percent, followed by Missouri at 25 percent. Utah, at 9.2 percent, had the lowest smoking rate among states.

The national increase in the smoking rate was so small, it could be just a blip, so health officials and experts say smoking prevalence is flat, not rising. But they are unhappy.

"Clearly, we've hit a wall in reducing adult smoking," said Vince Willmore, spokesman for the Campaign for Tobacco-Free Kids, a Washington, D.C.- based research and advocacy organization.

There's a general perception that smoking is a fading public health danger. Feeding that perception are indoor smoking laws, cigarette taxes and Congress' recent decision to allow the Food and Drug Administration to regulate tobacco.

But health officials believe gains have been undermined by cuts in state tobacco control campaigns. Some advocates believe tobacco companies are overcoming increasing obstacles.

Cigarette marketing has persisted and is effectively reaching kids and minorities with messages about flavored or menthol products, said Dr. Clyde Yancy, president of the American Heart Association.

The tobacco industry also has been discounting cigarettes to offset tax increases and keep smokes affordable, Willmore said.

Between 1997 and 2004, the average retail price of a pack of cigarettes — adjusted for inflation — jumped 63 percent, and adult smoking declined about 15 percent. Between 2004 and 2008, the price rose just 2 percent, while adult smoking declined by just about 1 percent, he said, citing industry sales data.

"There's a clear correlation," Willmore said.

Cigarette smoking is the leading preventable cause of death and illness in the United States, and is a cause of cancers, heart disease and other fatal conditions.

The adult smoking rate has been dropping, in starts and stops, since the mid-1960s when roughly 2 out of 5 U.S. adults smoked. Now it's 1 in 5. However, federal health goals for the year 2010 had hoped to bring the rate down to close to 1 in 10.

Adult smoking hovered at about 21 percent from 2004 to 2006, then dropped a full percentage point in 2007, said Dr. Matthew McKenna, director of the CDC's Office on Smoking and Health.

The 2007 drop gave CDC officials hope that U.S. smoking was plummeting again. "Now that appears to be a statistical aberration," McKenna said.

The new survey's results come from in-person interviews of nearly 22,000 U.S. adults.

The study was released Thursday and published in the CDC publication, Morbidity and Mortality Weekly Report.

Many of the states that have the lowest smoking rates are those that have been the most aggressive about indoor smoking laws and about state taxes that drive up the cost of cigarettes, said Dr. Thomas Frieden, the CDC's director.

Health officials are optimistic that more and more smokers will be discouraged from lighting up by escalating cigarette taxes, including a 62-cent federal tax that took effect in April. That may cause smoking to go down when the 2009 smoking data comes in, some advocates said.

Perhaps the recession will have an impact, too.

"In general, when people have less money, they smoke less," Frieden said. "Time will tell."