Even America’s millionaires are thinking about inflation’s impact on savings.

Researchers at the Phoenix Companies Inc., Hartford, have published figures supporting that conclusion in a summary of results from a survey of about 1,900 U.S. adults who have a net worth of $1 million or more, excluding the value of their primary residences.

Only 54% of the 2008 survey participants said they feel wealthier in 2008, down from 81% in 2007.

The percentage of participants who said they are “very optimistic” about their financial future fell to 25%, from 34%.

In addition, 58% of the 2008 survey participants said that the U.S. economy is in a downturn and that the worst is yet to come.

The Phoenix researchers found that 40% of the high-net-worth individuals surveyed worry that their assets will be exhausted too quickly or that they will not be able to live comfortably on their retirement income, compared with 36% who expressed such concerns in 2007.

The percentage of participants who fear that inflation will erode the value of their retirement income has increased to 50%, from 42%, while the percentage who fear poor investment performance will reduce the value of their assets increased to 39%, from 33%.

Despite the participants’ concerns, 50% rarely seek professional advice when making major financial decisions, up from 45% in 2007, and 41% of the 2007 participants said they do not have a primary financial advisor.