Fornari et al. BMC Public Health 2010, 10:574 http://www.biomedcentral.com/1471-2458/10/574 Marital status has been found to be associated with general mortality in many studies conducted in the United States [12], European countries [13,14] and Japan [15]. In particular, elevated mortality risk was associated with single status for both genders, whereas the link between mortality and divorce or widowhood was found only in men [14,15]. Indeed, unmarried men and women tended to engage in more unhealthy beha- viours (smoking, physical inactivity and low interest in health screening) and to experience more psychological distress [16]. On the contrary, the social ties and family support, provided by marriage, seemed to reduce the risk of mortality from major disease of all causes [12]. From the second half of the 1970 s, in Italy as in most Western European countries, CVD mortality decreased across the whole country, mainly in the Northern regions, where rates were originally higher [17,18]. During the Nineties almost two thirds of the decrease in coronary mortality were due to the reduction in 28-day case-fatality [19]. The incidence of coronary disease decreased too, but less than mortality. Case-fatality decreased both for total events (largely explained by the reduction of out-of-hospital deaths) and for hospitalised cases (in the same period, medical management of cardi- ovascular events underwent an impressive improvement) [20]. Only a few studies documented the incidence and case-fatality of cerebrovascular disease in Italy [21,22]. Rates seemed to decline but comparison in time was difficult due to the lack of standard criteria of classifica- tion and the discontinuity of data collection. Major cardi- ovascular risk factors (total cholesterol, blood pressure and cigarette smoking) showed a progressive decrease, even in the absence of systematic and active preventive interventions [23]. The aims of this study were to explore the relation- ship between education, marital status and major cardi- ovascular risk factors and to evaluate the role of such indices of social status in predicting circulatory events and deaths in Italian cohorts. The studied population is characterized by a relatively low incidence of the disease, usually attributed to the Mediterranean diet [24-26] and, so far, differently from Northern Europe, not clearly or weakly influenced by social conditions. Methods Population Twelve population-based cohorts from the North and the Centre-South of Italy involved in the Progetto CUORE were investigated [27]. Within the frame of the WHO MONICA Project, six samples were selected from 25-64 year-old residents of two Northern Italian areas: in Brianza (Lombardy) the cohorts were enrolled in 1986, 1990, 1993 and in Friuli in 1986, 1989, 1994 [28]. The PAMELA Study was a random sample of Page 2 of 9 25-74 year-old residents of the town of Monza (Lom- bardy) investigated in 1990-93 by the MONICA Brianza team [29]. The Friuli Emostatico study was a random sample of the 45-64 year-old residents of the town of Udine in Friuli, enrolled in 1995-96 and inves- tigated by the MONICA Friuli team. The MATISS study selected three independent cohorts from the general population in the age group of 20-69 years of the Latina Province, an area located in the south of Rome, in 1984, 1987 and 1993 respectively [30]. Finally, the Progetto ATENA cohort was selected from the 30-69 year-old female population of Naples in 1993-1997 [31]. These cohorts were originally included in the Progetto CUORE to assess cardiovascular risk factor prevalence and CVD morbidity and mortality time trends from the first half of the 1980s to the first half of the 1990s. The present analysis is restricted to 13127 women and 7520 men in the age group of 35-69 years and free of previous cardiovascular events at baseline [27]. The follow-up of major cardiovascular events continued until December 2002, for an average period of 11 years: the percentage of losses to follow- up is less than 5% in all cohorts. The CUORE Project received approval from the Ethics Committee of the Istituto Superiore di Sanità in 2006, 2008 and 2009. At the baseline visit all the participants gave the con- sent for the follow-up of mortality and cardiovascular morbidity in the respect of the Italian privacy low. Cardiovascular risk factors and social status Cardiovascular risk factors were measured at baseline adhering to the procedures and quality standards of the WHO-MONICA project [28]. Briefly, blood pressure was measured twice on the right arm with a standard mercury sphygmomanometer on sitting subjects, at rest for at least 10 minutes. Systolic and diastolic blood pres- sures were recorded as the first and fifth phase of Kor- otkoff sounds. The average of the two measurements, taken five minutes apart, was used as the study variable. Venous blood specimens were taken after overnight fast- ing. Serum total and HDL-cholesterol were assayed by the enzymatic method in the collaborating laboratories. Triglycerides were determined using the GPO_PAP enzymatic colorimetric method or the Trinder method. Weight and height were measured in participants without shoes and with light clothing and they were used to compute the body mass index (BMI). A stan- dard questionnaire was administered to collect informa- tion on cigarette smoking, diabetes, medications and history of CVD. Smoking status was classified as a dummy variable which identify smokers (current smo- kers or subjects who stopped smoking less than 12 months ago) and non-smokers (never smoked or past smokers who stopped smoking at least 12 months ago