The worsening trend in heart disease despite improving treatments is because of lifestyle factors such as smoking and lack of exercise, experts say.

Between 1993 and 2003 the largest relative increase in obesity has been

in adults under 45, while cholesterol levels have changed little or even increased among the younger age groups.

At the same time the decline in smoking, which is a key risk factor for heart disease, may be levelling off among young adults. A quarter of adults still smoke.

Any change in the trend is likely to be seen soonest in younger people. The younger age group suffers relatively few heart attacks or deaths, so has yet to have any impact on overall figures, which continue to decline. But as this group gets older, the risk is that heart disease deaths will increase again.

Simon Capewell, Professor of Clinical Epidemiology at the University of Liverpool and an expert on heart disease statistics, said: “We think this recent flattening of heart disease death rates is a real phenomenon. It has also been reported by us in the US, and by colleagues in Australia.

“We also think that increases in obesity and diabetes may contribute, but do not provide the whole answer,” Professor Capewell said.

One of the most alarming findings was published last year in the Journal of the American College of Cardiology by Professor Capewell and an American colleague, Earl Ford, of the US Public Health Service.

This showed that in the United States, deaths from heart disease among women aged 35 to 54 fell by 5.4 per cent a year in the 1980s, and by 1.2 per cent a year in the 1990s, but increased by 1.5 per cent a year between 1997 and 2002.

Dr Ford said: “Young adults should take stock of their lifestyles. If you’re smoking, you should quit. If you’re doing less than 30 minutes of physical activity a day, it’s time to find ways to be more active.”

Professor Philip Greenland, of Northwestern University in Chicago, wrote in the journal: “This should be regarded as a wake-up call. The take-home message is that heart disease has not gone away, continues to be a problem and could become a greater problem.”

Better treatments accounted for about 40 per cent of the decline in the rate of heart disease, while lifestyle changes, such as lower smoking levels, accounted for another 50 per cent. Some 10 per cent is unaccounted for.

When the Department of Health set its targets to cut heart deaths in people under 75 by 40 per cent, it knew of the trends and that the target was achievable.

But the new evidence of growing problems in the middle-aged suggests that it may get a lot harder.

Arresting problem

— Coronary heart disease caused 101,000 deaths in the UK in 2005: 56,000 men and 45,000 women. It is the most common cause of death below the age of 75

— Death rates for men aged 35-44 have fallen dramatically to less than 40 per cent of the 1968 rate. The same is true among women. But the decline is now stalling

— The actual number of deaths in this age group is very small, but the implications for their future health are large

Source: Times database

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