ATLANTA - U.S. life expectancy has hit another all-time high - 77.6 years - and deaths from heart disease, cancer and stroke continue to drop, the government reported Thursday.

Still, the march of medical progress has taken a worrisome turn: Half of Americans in the 55-to-64 age group - including the oldest of the baby boomers - have high blood pressure, and two in five are obese. That means they are in worse shape in some respects than Americans born a decade earlier were when they were that age.

The health of this large group of the near-elderly is of major concern to American taxpayers, because they are now becoming eligible for Medicare and Social Security.

Life expectancy in the U.S. has been rising almost without interruption since 1900, thanks to extraordinary advances in medicine and sanitation, and declines in some types of unhealthy behavior, such as smoking.