Re-survey of the Whitehall study of London civil servants: changes in riskfactors for cardiovascular disease during 29 years of follow-up

Background Substantial uncertainty persists about the relevance of blood pr essure and cholesterol to the risk of cardiovascular disease in the elderly . Objective To investigate the determinants of cardiovascular risk in old age , and the relevance of such risk factors when recorded in middle and old ag e. Methods A re-survey in 1997 of 8537 survivors of a cohort of men who were o riginally examined in 1967-1970 when aged 40-69 years. Results Completed questionnaires were received from 7050 (82%) of the survi vors, and blood pressure and blood samples from 5427 (64%), The response ra te declined with increasing age, was inversely related to markers of socioe conomic status in 1967-70 and in 1997, and was lower in those who had been current smokers or had a higher blood pressure level in 1967-70, After excl uding those with reported cardiovascular disease (25% of respondents), the mean levels of total cholesterol and apolipoprotein B were lower in older a ge groups, whereas apolipoprotein A, levels did not vary much with age. Amo ng those with risk factors recorded both in 1967-70 and 1997, the prevalenc e of smoking had declined by two-thirds (32% in 1970 and 12% in 1997), the prevalence of diabetes had increased (0.3% versus 4.5%), and the mean systo lic blood pressure had increased by 16 mmHg (130 versus 146 mmHg), but the diastolic blood pressure had not changed materially (80 versus 81 mmHg), an d the measured levels of total cholesterol had increased by 0.5 mmol/l (alt hough that change may be artefactual), Conclusion Follow-up of vital status in this cohort should permit an assess ment of the relevance of risk factors recorded in middle and old age to car diovascular disease in old age. (C) 2000 Lippincott Williams & Wilkins.