Can a decline in the population means of cardiovascular risk factors reduce the number of people at risk?

Abstract

OBJECTIVE To prove the possibility of shifting distribution of cardiovascular risk factors for a whole population over time and thereby to influence the prevalence of the corresponding disease states, according to the theory stated by Geoffrey Rose in 1985. DESIGN Examination of standardised data from the German Cardiovascular Prevention Study (GCP), a seven year long, population-based, multicentre intervention trial, concerned with decreasing risk factors for cardiovascular disease. SETTING AND SUBJECTS three cross sectional surveys of a population 25 to 69 years old in six study regions, and three nationwide cross sectional surveys in the former West Germany in 1984, 1988 and 1991. MAIN OUTCOME MEASURES The relation between the population mean for systolic and diastolic blood pressure, total serum cholesterol, body mass index, and alcohol intake, and the prevalence of the corresponding disease states, as are systolic (⩾140 and ⩾160 mm Hg) and diastolic hypertension (⩾90 and ⩾95 mm Hg), hypercholesterolaemia (⩾250 and ⩾300 mg/dl), overweight (body mass index ⩾30 kg/m²), and heavy drinking (weekly alcohol intake ⩾300 g/week). Results are expressed as linear regression equations and Pearson correlation coefficients. RESULTS The correlation between the mean population values and prevalence of disease was close for blood pressures and body mass index. The Pearson coefficients, corrected for the influence of values increased above borderlines, were 0.86 and 0.81 respectively for systolic blood pressure, 0.88 and 0.91 for diastolic blood pressure, 0.28 and 0.52 for cholesterol, and 0.86 for the body mass index. The coefficient for alcohol intake was 0.55. CONCLUSIONS It seems possible to shift the risk distribution of a population for some physiological parameters over time with the effect of changing the disease prevalence. This strategy can be used successfully for specific preventive measures, as was strongly advocated by Geoffrey Rose.