Risk factors for ischaemic heart disease in a Cretan rural population: a twelve year follow-up study

Abstract

Background: Crete has been of great epidemiological interest ever since the publication of the Seven Countries Study. In 1988 a well-defined area of rural Crete was studied, with only scarce signs of coronary heart disease (CHD) despite the unfavorable risk profile. The same population was re-examined twelve years later aiming to describe the trends of CHD risk factors over time and discuss some key points on the natural course of coronary heart disease in a rural population of Crete.

Methods and results: We re-examined 200 subjects (80.7% of those still living in the area, 62.4 +/- 17.0 years old). The prevalence of risk factors for CHD was high with 65.9% of men and 65.1% of women being hypertensive, 14.3% of men and 16.5% of women being diabetic, 44% of men being active smokers and more than 40% of both sexes having hyperlipidaemia. Accordingly, 77.5% of the population had a calculated Framingham Risk Score (FRS) > or = 15%, significantly higher compared to baseline (p < 0.001). The overall occurrence rate for CHD events was calculated at 7.1 per 1000 person-years (95% confidence interval: 6.8-7.3).

Conclusion: The study confirms the unfavorable risk factor profile of a well defined rural population in Crete. Its actual effect on the observed incidence of coronary events in Cretans remains yet to be defined.

Figure 1

Study population. Study population presented schematically. The signs ♂ and ♀ represent men and women respectively.

Figure 2

FRS in 1988 and 2001. Framingham Risk Score (FRS) scatter plots in comparable age groups at baseline (1988, Phase I) and follow up (2001, Phase II).

Figure 3

Survival curves according to the FRS group. Coronary Heart Disease survival free curves for each one of the FRS groups. Test of equality of survival distributions for different FRS groups: Log Rank (Mantel-Cox) χ² = 13.828, df = 2, p < 0.001.