Middle aged men who smoke, have high blood pressure and high cholesterol can expect to live 10 to 15 years less than their healthy counterparts, according to a large UK study that followed nearly 19,000 men for 38 years.

These are the conclusions of a study published 17 September in the British Medical Journal, BMJ. The British Heart Foundation (BHF) sponsored the study, which was led by the University of Oxford.

The findings come from the “Whitehall” study which has been following 19,000 men aged 40 to 69 employed in the civil service in London since they enrolled in 1967-70 when they underwent initial medical exams. The BHF funded the follow up exams and health records.

The researchers found that the presence of three heart disease risk factors in men aged 50 could result in a reduced life expectancy of 10 to 15 years. The three key heart disease risk factors are: smoking, high blood pressure and high cholesterol.

Medical Director of the BHF, Professor Peter Weissberg told the press that this important study “puts a figure” on how much shorter your life is likely to be if you smoke, have high blood pressure and high cholesterol in middle age.

For the prospective cohort study, the researchers examined data on 18,863 men who were examined at entry in 1967-70 and followed for 38 years. During that time 13,501 died and 4,811 had follow up exams in 1997.

The main outcome measure they assessed was life expectancy in relation to smoking, low or high blood pressure (greater or equal to 140 mm Hg) and low or high cholesterol (greater or equal to 5 mmol/l), and a combined risk score from these and other factors.

The results showed that:

  • On enrollment 42 per cent of the men were current smokers, 39 per cent had high blood pressure and 51 per cent had high cholesterol.

  • At the follow up exams, about two-thirds of the men who were current smokers at entry had quit just afterwards.

  • This coincided with a corresponding two-thirds drop in the mean differences in levels of those with high and low levels of blood pressure and cholesterol.

  • Compared with having none of the risk factors when they started the study, having all three risk factors at the start of the study was linked to a life span that was shorter by 10 years from age 50 (ie men with all three risk factors at baseline lived another 23.7 as opposed to 33.3 years for those with none).

  • Compared with participants in the lowest 5 per cent of a risk score that took into account smoking, diabetes, employment grade, and continuous levels of blood pressure, cholesterol concentration and BMI (body mass index), those in the highest 5 per cent had a life span that was 15 years shorter from age 50 (ie the highest risk group lived 20.2 more years compared to 35.4 more years in the lowest risk group).

The researchers concluded that:

“Despite substantial changes in these risk factors over time, baseline differences in risk factors were associated with 10 to 15 year shorter life expectancy from age 50.”

Although the study involved only male volunteers, the BHF said there is no reason why the findings should not apply to women.

Weissberg pointed out that the good news from this study is we can make changes to help us live a longer and healthier life, even after 50.

“We know that stopping smoking and reducing blood pressure and cholesterol, by lifestyle changes and/or tablets, can prevent the onset of heart disease — and these findings suggest it could make a decade of difference to our lives,” he added.

The BHF urges all men and women over 40 to go to their GP and have a health check to establish any areas of concern and start addressing them.

According to a BBC report, first author Dr Robert Clarke of of the Clinical Trial Service Unit at Oxford University said:

“We’ve shown that men at age 50 who smoke, have high blood pressure and high cholesterol levels can expect to survive to 74 years of age, while those who have none of these risk factors can expect to live until 83.”

Clarke said the study showed that “modest differences in heart risk factors can accurately predict significant differences in life expectancy”, adding that:

“If you stop smoking or take measures to deal with high blood pressure or body weight, it will translate into increased life expectancy. ”

“Life expectancy in relation to cardiovascular risk factors: 38 year follow-up of 19 000 men in the Whitehall study.”
Robert Clarke, Jonathan Emberson, Astrid Fletcher, Elizabeth Breeze, Michael Marmot, Martin J Shipley.
BMJ 2009;339:b3513
Published 17 September 2009
doi:10.1136/bmj.b3513

Additional sources: British Heart Foundation, BBC.

Written by: Catharine Paddock, PhD