Men who have multiple cardiovascular risk factors in middle age may have a reduced life expectancy of 10-15 years from age 50, according to the Whitehall study. Smoking, high blood pressure and raised cholesterol together reduced life span by 10 years. When other risk factors were also considered life expectancy was reduced by a further 5 years.

The Whitehall study was conceived in the late 1960s when cardiovascular mortality was uncomfortably high. A cohort of 18,863 male civil servants, aged 40-69, were enrolled and examined between 1967 and 1970 then followed for 38 years. The study’s primary objective was to determine the effect of risk factors on cardiovascular mortality. Further aims were to compare trends in vascular and non-vascular mortality in the study cohort with those in the general UK population; to estimate life expectancy from age 50 in relation to single baseline measurements of the three main vascular risk factors - smoking, BP, and cholesterol - both alone and in combination; and to estimate life expectancy in relation to a more accurate risk profile, including smoking, BP, cholesterol, diabetes, BMI and employment grade.

During the course of the study 13,501 participants died (72%). A total of 4,811 men were reexamined in 1997. The results showed that at entry to the study 42% of the participants were smokers, 39% were hypertensive defined as systolic BP ≥140 mm Hg and 51% had raised cholesterol defined as ≥5.0mmol/l.

Men with all three risk factors at entry into the study had their life expectancy reduced by 10 years from age 50 compared with those men with no risk factors. If the more detailed risk assessment based on smoking, diabetes, employment grade, continuous levels of BP, cholesterol, and BMI was used then men in the highest risk quintile had their life expectancy reduced by 15 years compared with those in the lowest quintile.

The authors commented that although almost two-thirds of the participants stopped smoking and many showed improvements in the other risk factors over time the presence of the three main risk factors, smoking, hypertension and raised cholesterol, at baseline was associated with a marked reduction in life expectancy from age 50, a three-fold higher rate of vascular mortality and a two-fold higher rate of non-vascular mortality.

The study cohort fared slightly better than the general population in terms of life expectancy. This is best expressed in terms of employment status and in the study cohort life expectancy varied from 74.8 to 80.2 years between the lower and upper employment grades compared with UK men in the registrar general’s classification (72.7 in grade V to 80 in grade I).

The study had several strengths including the prospective design, large sample size and long follow-up. There were also a large number of deaths during the course of the study and the mortality follow-up was as near to complete as could be hoped for. However, it was not without weaknesses. First, it was a single sex study and total cholesterol was used rather than a complete lipid profile with lipoprotein breakdown. Second, the effect of risk factors on mortality may have been underestimated by the increased use of pharmacotherapy during follow-up. The 1997 data confirmed this with 29% of participants taking aspirin and 28% antihypertensives. Only 2% were taking statins but this was in a different evidence and guideline climate.

The other potential confounding factor is the so called ‘healthy worker’ effect of studying an employed cohort working in the civil service. This could account for longer life expectancies than in the general population but as the authors point out would not affect the comparisons of risk factors within the study cohort.

The findings lend support to the current public health policies which aim to produce small changes in major risk factors at a population level to achieve significant improvements in cardiovascular mortality and life expectancy. Furthermore, the findings support the aggressive medical treatment of patients with high CVD risk.