German Origin Clusters for High Cardiovascular Risk in an Italian Enclave
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German Origin Clusters for High Cardiovascular Risk in an Italian Enclave Edoardo CASIGLIA,1 MD, Giancarlo BASSO,2 MD, Francesco GUGLIELMI,1,2 MD, Bortolo MARTINI,2 MD, Alberto MAZZA,1 MD, Valérie TIKHONOFF,1 MD, Roberta SCARPA,1 MD, Mario SAUGO,3 MD, Sandro CAFFI,3 MD, and Achille C. PESSINA,1 MD SUMMARY Mortality and morbidity appear to be higher in a Cimbrian population representing an enclave of people who migrated from medieval Germany to the secluded Leogra valley in Italy. A population-based study was organized, recruiting 881 elderly subjects of Cimbrian origin and comparing them with a standard control population (SCP, n = 3282) having comparable general characteristics and lifestyle. Serum lipids and glucose, blood pressure, heart rate, respiratory function, ECG abnormalities, and historical events were used as risk indicators. Age-adjusted systolic and pulse pressure were higher in the Cimbrians than in the SCP, while diastolic blood pressure was comparable. The prevalences of arterial hyper- tension, isolated systolic hypertension, and pulse hypertension were significantly more represented among Cimbrians than SCP. The prevalences of diabetes, hypercholester- olemia, and hypertriglyceridemia were higher among the former than the latter. The ratio between apolipoproteins B and A1 was also higher, while the HDL fraction was signifi- cantly lower in Cimbrians than in the SCP. In Cimbrians, the relative risk (RR) for ischemic heart disease was 1.92 (1.57-2.34) in women, 2.30 (1.54-3.43) in men and 1.03 (1.00-1.06) in women for stroke, 2.43 (1.54-3.83) in men and 1.45 (1.01-1.12) in women for atrial fibrillation, 3.85 (2.83-5.24) in men and 1.39 (1.20-1.60) in women for respira- tory disease, 1.97 (1.32-2.94) in men and 6.81 (4.38-10.60) in women for intermittent claudication, and 3.31 (2.44-4.50) in men and 2.30 (1.76-3.01) in women for left ventric- ular hypertrophy. The subjects living in the secluded Leogra valley are at higher cardiovascular risk than the standard controls. Whether this depends on genetic factors, lifestyle, or both will need to be clarified by further analysis. (Int Heart J 2005; 46: 489-500) Key words: Cardiovascular risk, Special populations, Genetics, Epidemiology From the 1Department of Clinical and Experimental Medicine, University of Padova, Padova, 2Cardiac Unit, General Hos- pital of Schio-Thiene, Schio, and 3Direction and Epidemiological Department of the Local Health Unit No. 4, Thiene, Italy. Address for correspondence: Edoardo Casiglia, MD, Department of Clinical and Experimental Medicine, University of Padova, Via Giustiniani, 2 35128 Padova, Italy. Received for publication August 12, 2004. Revised and accepted December 17, 2004. 489 Int Heart J 490 CASIGLIA, ET AL May 2005 NO experimental model of ageing is available in humans and epidemiological observation of the general population is the best approximation. Migration and segregation are quasi-experimental models at a population level.1-3) Our group previously had the opportunity to verify this model at a population level by study- ing African and South American people living in different contexts.1,2,4,5) In 1999, a special Italian population came to our attention. This population - called Cimbrian - has 4 interesting characteristics: it is of middle-European ori- gin although the people have been living in Italy for many centuries, it is located in a secluded valley, it underwent emigration but low or absent immigration, and it shows higher mortality and morbidity due to complications of arteriosclerosis in comparison to neighbouring areas.6) In a preliminary analysis of mortality based on records from the government, hospitals, and physicians, the standard- ised mortality ratio for coronary heart disease (CAD) was 1.36 (95% confidence 6) intervals [95%CI] 1.13-1.62) in males, and 1.29 (95%CI 1.06-1.57) in females. From 983 to 1287 AD, people from Germany crossed the Alps and settled in different uninhabited areas of the North Italian mountains between Vicenza, Verona, and Trento. They were called Cimbrian (from tzimbarn, woodcutter),7) maintained German traditions and a medieval German-like language (the Toish or Tausch), and preferred not to integrate or assimilate with the natives. Linguis- tic analysis demonstrates that the first came from Bavaria and particularly from an area under the jurisdiction of the Benediktbeuern abbey. Groups of German tzimberer then migrated to Asiago, Posina, Folgaria, Lavarone, Luserna, Valli del Leno, and Vallarsa, and in 1287 to the Lessinia area. Those now living in the val- ley or by the Leogra River, coming in 1200 AD from Posina, remained secluded, intermarried, and are still recognizable for their German or German-like family names and traditions. In Europe, they are the most South-settled Germanic- speaking people. While important emigration interested North Italy in past centu- ries, practically no immigration was recorded in the Leogra valley, so the present inhabitants must be considered to be of German strain.7) This study was performed in order to evaluate whether the prevalence of cardiovascular risk factors actually is higher in elderly subjects from the above- mentioned Cimbrian population than in elderly subjects living in the neighbour- ing areas, which may explain their less favourable outcome, by comparing these Cimbrians with a control standard population. The decision to focus on the elderly was based on the consideration that the epidemiology of cardiovascular risk in the elderly is far from being defined. Although a limited number of elderly subjects have been included as fringe groups in general epidemiological investigations, only a few studies have had an elderly population as the main target group. The only Italian study with these characteristics is the CArdiovascular STudy in the ELderly (CASTEL),8-10) per- Vo l 4 6 No 3 CIMBRIANS OF GERMAN ORIGIN IN ITALY 491 formed by our group on a representative cohort of 3,282 subjects of the Italian general population. METHODS Cimbrian study population: The LEOGRA study8) was conceived as a longitudi- nal study aimed at evaluating in the long term the incidence and relative weight of the cardiovascular risk factors in the elderly, as well as the feasibility of an interventional program of cardiovascular prevention. The study cohort consisted of 881 subjects (350 men and 531 women), aged 65 years or over, representative of all the elderly living in the Leogra valley (namely in Valli del Pasubio and Tor- rebelvicino). The data obtained from the initial cross-sectional survey are described herein. Data from longitudinal analysis, including the incidence of new cases of hypertension, morbidity, and mortality, will be available in the next few years. For the purpose of the present analysis, 881 elderly subjects aged 65 years or over living in the Leogra valley, identified as “Cimbrian” according to criteria based on history and on family names,7) were invited by letter to visit to a local general hospital. Although the area selected for the study offered a great number of pre-existing medical facilities (some even being considered the most advanced in Italy in this respect), a special epidemiological unit was organized within a hospital, with a staff from the University of Padua dedicated to the study. Before the clinical examination, all subjects underwent blood tests and a very detailed questionnaire concerning personal data, lifestyle, smoking and drinking habits, nutrition, physical activity, quality of life, and personal and familial medical history.11-13) Anthropometrics were taken in light underwear without shoes. Body mass index (BMI) was calculated from the Quatelet algorithm. Blood pressure (dias- tolic Korotkoff phase 5) was taken in triplicate both in lying and standing posi- tions by trained doctors using a mercury sphygmomanometer at 10-min intervals, taking special care to avoid any terminal digit preference. The average of the last two clinostatic measurements was taken as BP, to minimise white-coat effects, if any. Heart rate was also taken at the same time. Standard 12-lead electrocardio- grams were performed in the morning and blindly codified according to the Min- nesota code14) by an expert who did not know the aim and design of the study. All subjects underwent spyrometry by means of a Pony Spyrometer class I type B (Cosmed, Rome, Italy). Vital capacity (VC in l) and forced expiratory volume in 1 second (FEV1 in l) were measured. Theoretical VC and FEV1 were then calcu- lated for each subject, and individual pulmonary function was defined for each individual as a percent of the theoretical values. Int Heart J 492 CASIGLIA, ET AL May 2005 Standard control population: Elderly subjects included in the CASTEL, who did not differ from the study population with respect to lifestyle, diet, and habits (Table I), were used as the standard control population (SCP). The protocol of the CASTEL, described elsewhere,9,10,15-18) was identical to that used for studying the Cimbrian elderly population. All elderly subjects aged 65 years or over in the Ital- ian towns of Castelfranco, Veneto, and Chioggia were invited by letter to visit to a clinic organised at the local general hospital; 3,282 (73%) accepted the study protocol and were enrolled. After signing an informed consent form, each subject underwent the same procedures as in the LEOGRA protocol. Statistical analysis: SAS software (version 8.1, SAS Institute, Cary, NC) was used for statistical analysis. According to power analysis based on the results of the CASTEL study, the number of Cimbrian subjects was adequate for statistical analysis. Values of continuous variables are expressed as the mean and standard devi- ation and the 95%CI is indicated when appropriate. Analysis of variance using the Table I.