Role of known risk factors in explaining the difference in the risk of coronary heart disease between eastern and southwestern Finland

Consideration of hereditary effects in the radiological protection system: evolution and current status

PURPOSE

The purpose of this paper is to provide an overview of the methodology used to estimate radiation genetic risks and quantify the risk of hereditary effects as outlined in the ICRP Publication 103. It aims to highlight the historical background and development of the doubling dose method for estimating radiation-related genetic risks and its continued use in radiological protection frameworks.

RESULTS

This article emphasizes the complexity associated with quantifying the risk of hereditary effects caused by radiation exposure and highlights the need for further clarification and explanation of the calculation method. As scientific knowledge in radiation sciences and human genetics continues to advance in relation to a number of factors including stability of disease frequency, selection pressures, and epigenetic changes, the characterization and quantification of genetic effects still remains a major issue for the radiological protection system of the International Commission on Radiological Protection.

CONCLUSION

Further research and advancements in this field are crucial for enhancing our understanding and addressing the complexities involved in assessing and managing the risks associated with hereditary effects of radiation.

Periodic trends in geographical variation of prostate cancer incidence and mortality in Finland between 1985 and 2019

BACKGROUND

Evaluation of regional variation of prostate cancer (PCa) incidence and PCa-specific mortality is essential in the assessment of equity in a national healthcare system. We evaluated PCa incidence and PCa-specific mortality between different municipalities and hospital districts in Finland over 1985-2019.

MATERIAL AND METHODS

Men diagnosed with PCa in Finland from 1985 through 2019 were retrieved from Finnish Cancer Registry. Age-standardized PCa incidence and mortality rates were estimated by municipality and hospital district as well as municipality urbanization, education, and income level using hierarchical Bayesian modeling. Standard deviations (SD) of the regional rates were compared between periods from 1985-1989 to 2015-2019.

RESULTS

We identified 123,185 men diagnosed with any stage PCa between 1985 and 2019. SD of PCa incidence rate (per 100,000 person-years) showed that the total variation of PCa incidence between different municipalities was substantial and varied over time: from 22.2 (95% CI, 17.1-27.8) in 1985-1989 to 56.5 (95% CI, 49.8-64.5) in 2000-2004. The SD of PCa mortality rate between all municipalities was from 9.0 (95% CI, 6.6-11.8) in 2005-2009 to 2.4 (95% CI, 0.9-4.8) in 2015-2019. There was a trend toward a lower PCa-specific mortality rate in municipalities with higher education level.

DISCUSSION

Regional variation in the incidence rate of PCa became more evident after initiation of PSA testing in Finland, which indicates that early diagnostic practice (PSA testing) of PCa has been different in different parts of the country. Variation in the national PCa mortality rate was indeed recognizable, however, this variation diminished at the same time as the mortality rate declined in Finland. It seems that after the initiation period of PSA testing, PSA has equalized PCa mortality outcomes in Finland.

Substantial Within-Country Variation in the Incidence of Subarachnoid Hemorrhage: A Nationwide Finnish Study

OBJECTIVE

To study whether the incidence of subarachnoid hemorrhage (SAH) varies between geographic regions of Finland.

METHODS

By utilizing the nationwide Causes of Death and Hospital Discharge Registers, we identified all first-ever, hospitalized, and sudden-death (dying before hospitalization) SAH events in Finland between 1998 and 2017. Based on the patients' home residence, we divided SAHs into 5 geographic regions: southern, central, western, eastern, and northern Finland. We calculated crude and European age-standardized (European Standard Population [ESP] 2013) SAH incidence rates for each region and used a Poisson regression model to calculate age-, sex-, and calendar year-adjusted incidence rate ratios (IRRs) and 95% confidence intervals for regional and time-dependent differences.

RESULTS

During the total 106,510,337 cumulative person-years, we identified 9,443 first-ever SAH cases, of which 24% resulted in death before hospitalization. As compared to western Finland, where the SAH incidence was the lowest (7.4 per 100,000 persons), the ESP-standardized SAH incidence was 1.4 times higher in eastern (10.2 per 100,000 persons; adjusted IRR, 1.37 [1.27-1.47]) and northern Finland (10.4 per 100,000 persons; adjusted IRR, 1.40 [1.30-1.51]). These differences were similar when men and women were analyzed independently. Although SAH incidence rates decreased in all 5 regions over 2 decades, the rate of decrease varied significantly by region.

CONCLUSION

SAH incidence appears to vary substantially by region in Finland. Our results suggest that regional SAH studies can identify high-risk subpopulations, but can also considerably over- or underestimate incidence on a nationwide level.

Comparison of the rates of stroke and acute coronary events in northern France

Background Although stroke and acute coronary events share several risk factors, few studies have compared population-level epidemiological surveillance indicators of the two diseases in the same age range and in the same geographical area. Design The objective of the present study was to compare the rate of acute coronary events with that of stroke among inhabitants aged from 35-74 years in Northern France (Lille). Methods All incident and recurrent acute coronary events and stroke events occurring in men and women over 2008-2014 were recorded using two population-based registries with several overlapping sources of case ascertainment for hospitalised/non-hospitalised and fatal/non-fatal events. Log-linear Poisson regression models were used to compare the event and mortality rates. Results The results showed that the incident rates of acute coronary event and stroke were similar except under 60 years. In this group (35-59 years), the incident rate of acute coronary events was 1.6-fold higher than that of stroke. In contrast, the attack (incident and recurrent) rates were higher for acute coronary events than for stroke (1.5-fold; p < 0.0001) - especially in men (1.8-fold; p < 0.0001). The mortality rate was 2.2-fold higher for acute coronary events than for stroke, independent of sex and age group ( p < 0.0001), as was the case-fatality rate (1.5-fold, p < 0.0001). Conclusion In Lille, the overall acute coronary event rate was higher than the stroke rate - especially among men, due to a higher risk of incident acute coronary event under the age of 65 and a higher risk of recurrent acute coronary event in the 65-74 year-old age range. Further efforts should be devoted to primary and secondary prevention strategies after acute coronary events.

40-Year CHD Mortality Trends and the Role of Risk Factors in Mortality Decline: The North Karelia Project Experience

In the 1960s and early 1970s, coronary heart disease (CHD) mortality in Finland was the highest in the world, and within Finland, mortality was particularly high in the eastern part of the country. The North Karelia Project, the first large community-based cardiovascular diseases prevention program was established in 1972 to reduce the extremely high CHD mortality through behavioral change and reduction of the main cardiovascular disease risk factors among the whole population of North Karelia, the easternmost province of Finland. During the 40-year period from 1972 to 2012, smoking prevalence, serum total cholesterol, and systolic blood pressure declined markedly, except a small increase in serum cholesterol levels between 2007 and 2012. From the early 1970s to 2012, CHD mortality decreased by 82% (from 643 to 118 per 100,000) among working-age (35 to 64 years) men. Among working-age women, the decline was 84% (from 114 to 17 per 100,000). During the first 10 years, changes in these 3 target risk factors explained nearly all of the observed mortality reduction. Since the mid-1980s, the observed reduction in mortality has been larger than the predicted reduction. In the early 1970s, premature CHD mortality (35 to 74 years) was about 37% higher among Eastern Finnish men and 23% higher among Eastern Finnish women, compared with men and women in Southwestern Finland. During the last 40 years, premature CHD mortality declined markedly in both areas, but the decline was larger in Eastern Finland and the mortality gap between the two areas nearly disappeared.

Mortality in middle-aged men with obstructive sleep apnea in Finland

INTRODUCTION

Obstructive sleep apnea (OSA) has been associated with an elevated rate of cardiovascular mortality. However, this issue has not been investigated in patients with elevated proneness to cardiovascular diseases. Our hypothesis was that OSA would have an especially adverse effect on the risk of cardiovascular mortality in Finnish individuals exhibiting elevated proneness for coronary heart diseases.

METHODS

Ambulatory polygraphic recordings from 405 men having suspected OSA were retrospectively analyzed. The patients were categorized regarding sleep disordered breathing into a normal group (apnea hypopnea index (AHI) < 5, n = 104), mild OSA group (5 ≤ AHI < 15, n = 100), and moderate to severe OSA group (AHI ≥ 15, n = 201). In addition, basic anthropometric and health data were collected. In patients who died during the follow-up period (at least 12 years and 10 months), the primary and secondary causes of death were recorded.

RESULTS

After adjustment for age, BMI, and smoking, the patients with moderate to severe OSA suffered significantly (p < 0.05) higher mortality (hazard ratio 3.13) than their counterparts with normal recordings. The overall mortality in the moderate to severe OSA group was 26.4 %, while in the normal group it was 9.7 %. Hazard ratio for cardiovascular mortality was 4.04 in the moderate to severe OSA and 1.87 in the mild OSA group.

CONCLUSIONS

OSA seems to have an especially adverse effect on the cardiovascular mortality of patients with an elevated genetic susceptibility to coronary heart diseases. When considering that all our patients had possibility of continuous positive airway pressure treatment and our reference group consisted of patients suffering from daytime somnolence, the hazard ratio of 4.04 for cardiovascular mortality in patients with moderate to severe disease is disturbingly high.

Birthplace in area with high coronary heart disease mortality predicts the severity of coronary atherosclerosis among middle-aged Finnish men who had migrated to capital area: the Helsinki sudden death study

BACKGROUND

Reasons why eastern-born male Finns have higher coronary heart disease (CHD) mortality than do western-born men are still unsettled. Recently, eastern birthplace was found to be an independent predictor of pre-hospital sudden cardiac death (SCD) in the new low-mortality area of residence.

AIM

To investigate the association of birthplace with high CHD mortality attributes to more severe coronary atherosclerosis among men migrated to the low-mortality capital area.

METHOD

Coronary atherosclerosis was measured in 373 western-born and 314 eastern-born out-of-hospital male deaths aged 33-70 years in Helsinki (The Helsinki Sudden Death Study), covering 24.6% of male deaths within this age-group. CHD risk factors were obtained from an interview of a next of kin.

RESULTS

In multivariate analysis there was a strong birthplace-by-age interaction with atherosclerosis (P = 0.0005). Eastern-born men <54 years had larger areas of fatty streaks (P = 0.0195), fibrotic plaque (P = 0.0133), calcification (P = 0.0009), total plaque area (P = 0.0011), and greater stenosis (P = 0.0004) in the left coronary compared to western-born men, independent of CHD risk factors. Amongst older men (>or=54 years) such an association no longer appeared.

CONCLUSION

Higher CHD mortality among eastern-born men may be due to more severe coronary atherosclerosis independently of CHD risk factors, reflecting Finns' two-phase settlement history.

High differentiation among eight villages in a secluded area of Sardinia revealed by genome-wide high density SNPs analysis

To better design association studies for complex traits in isolated populations it's important to understand how history and isolation moulded the genetic features of different communities. Population isolates should not “a priori” be considered homogeneous, even if the communities are not distant and part of a small region. We studied a particular area of Sardinia called Ogliastra, characterized by the presence of several distinct villages that display different history, immigration events and population size. Cultural and geographic isolation characterized the history of these communities. We determined LD parameters in 8 villages and defined population structure through high density SNPs (about 360 K) on 360 unrelated people (45 selected samples from each village). These isolates showed differences in LD values and LD map length. Five of these villages show high LD values probably due to their reduced population size and extreme isolation. High genetic differentiation among villages was detected. Moreover population structure analysis revealed a high correlation between genetic and geographic distances. Our study indicates that history, geography and biodemography have influenced the genetic features of Ogliastra communities producing differences in LD and population structure. All these data demonstrate that we can consider each village an isolate with specific characteristics. We suggest that, in order to optimize the study design of complex traits, a thorough characterization of genetic features is useful to identify the presence of sub-populations and stratification within genetic isolates.

Birthplace predicts risk for prehospital sudden cardiac death in middle-aged men who migrated to metropolitan area: The Helsinki Sudden Death Study

BACKGROUND

Eastern-born male Finns, irrespective of their place of residence, have high mortality from coronary heart disease (CHD), and half of such deaths are sudden.

AIM

To study whether eastern birthplace alone or combined with life-style factors predicts risk for prehospital sudden cardiac death (SCD) in the new (west) low-mortality area of residence.

METHOD

Prospective case-control autopsy study of all (700) out-of-hospital deaths of men aged 35-69 years in metropolitan Helsinki during 1981-82 and 1991-92. Data on CHD risk factors were obtained for 405, of whom 149 died of SCD (cases) and 256 of other causes (controls).

RESULTS

A birthplace-by-age interaction with SCD (P=0.024) and with myocardial infarction (P=0.005) appeared. Men < or =54 years born in the east were more often victims of SCD (odds ratio 2.99, 95% confidence interval 1.38-6.49, P=0.006) than were men born in the west, independently of CHD risk factors. SCD was predicted also by alcohol consumption, age, smoking, and hypertension. Amongst older (>54 years) men no association with birthplace was any longer evident, but alcohol and socio-economic status predicted SCD.

CONCLUSIONS

Birthplace-based risk for SCD suggests the contribution of early life environment or genetic east-west differences, reflecting Finns' two-phase settlement history.

The diabetes-cardiovascular risk paradox: results from a Finnish population-based prospective study

AIMS

To assess changes in coronary heart disease (CHD) event rates and CHD mortality rates among diabetic and non-diabetic individuals between two large study cohorts with baseline assessments 10 years apart and followed up for 10 years.

METHODS AND RESULTS

Four population surveys were carried out in 1972, 1977, 1982, and 1987 in a randomly selected independent population in Finland. For the analyses, we combined the 1972 and 1977 cohorts (cohort 1) and similarly also the 1982 and 1987 cohorts (cohort 2). A total of 16 779 men and 18 235 women were followed up for 10 years. Whereas the risk of first cardiovascular disease event in women did not change between the two cohorts, the risk in diabetic men aged 25-49 years and men of all age groups with incidence diabetes during the follow-up decreased compared with the earlier cohort. The relative risk of CHD mortality in men with baseline diabetes or incident diabetes compared with non-diabetic individuals increased (from 1.67 to 1.75 and 1.00 to 1.92, respectively). CHD event rates and CHD mortality rates decreased among non-diabetic individuals between the two study cohorts.

CONCLUSION

Special attention should be given to prevent the onset of diabetes in the population and to intensify the management of patients with diabetes.

Smoking in context - a multilevel approach to smoking among females in Helsinki

Background

Smoking is associated with disadvantage. As people with lower social status reside in less privileged areas, the extent of contextual influences for smoking remains unclear. The aims were to examine the spatial patterning of daily smoking within the city of Helsinki, to analyse whether contextual variation can be observed and which spatial factors associate with current daily smoking in the employed female population.

Methods

Data from a cross-sectional questionnaire were collected for municipal employees of Helsinki (aged 40–60 years). The response rate was 69%. As almost 4/5 of the employees are females, the analyses were restricted to women (n = 5028). Measures included smoking status, individual level socio-demographic characteristics (age, occupational social class, education, family type) and statistical data describing areas in terms of social structure (unemployment rate, proportion of manual workers) and social cohesion (proportions of single parents and single households). Logistic multilevel analysis was used to analyse data.

Results

After adjusting for the individual-level composition, smoking was significantly more prevalent according to all social structural and social cohesion indicators apart from the proportion of manual workers. For example, high unemployment in the area of domicile increased the risk of smoking by almost a half. The largest observed area difference in smoking – 8 percentage points – was found according to the proportion of single households.

Conclusion

The large variation in smoking rates between areas appears mainly to result from variation in the characteristics of residents within areas. Yet, living in an area with a high level of unemployment appears to be an additional risk for smoking that cannot be fully accounted for by individual level characteristics even in a cohort of female municipal employees.

Association of Chlamydia pneumoniae infection with HLA-B*35 in patients with coronary artery disease

The immune system may interplay between Chlamydia pneumoniae infection and coronary artery disease (CAD). Major histocompatibility complex genes regulate innate and adaptive immunity. Patients with CAD (n = 100) and controls (n = 74) were enrolled. Human leukocyte antigens (HLA-A, HLA-B, and HLA-DRB1), four lymphotoxin alpha single-nucleotide polymorphisms, and complement C4A and C4B allotypes were typed, and their haplotypes were inferred. The presence of serum C. pneumoniae immunoglobulin A (IgA) (titer, > or =40) or IgG (titer, > or =128) antibodies or immune complex (IC)-bound IgG antibodies (titer, > or =2) was considered to be a serological marker suggesting chronic C. pneumoniae infection. C. pneumoniae IgA antibodies were found more frequently in patients than in controls (P = 0.04). Among the patients, multiple logistic regression analysis showed the HLA-B*35 allele to be the strongest-risk gene for C. pneumoniae infection (odds ratio, 7.88; 95% confidence interval, 2.44 to 25.43; P = 0.0006). Markers of C. pneumoniae infection were found more frequently in patients with the HLA-A*03-B*35 haplotype than in those without the haplotype (P = 0.007 for IgA; P = 0.008 for IgG; P = 0.002 for IC). Smokers with HLA-B*35 or HLA-A*03-B*35 had markers of C. pneumoniae infection that appeared more often than in smokers without these genes (P = 0.003 and P = 0.001, respectively). No associations were found in controls. In conclusion, HLA-B*35 may be the link between chronic C. pneumoniae infection and CAD.

Regional differences among the Finns: A Y-chromosomal perspective

Twenty-two Y-chromosomal markers, consisting of fourteen biallelic markers (YAP/DYS287, M170, M253, P37, M223, 12f2, M9, P43, Tat, 92R7, P36, SRY-1532, M17, P25) and eight STRs (DYS19, DYS385a/b, DYS388, DYS389I/II, DYS390, DYS391, DYS392, DYS393), were analyzed in 536 unrelated Finnish males from eastern and western subpopulations of Finland. The aim of the study was to analyze regional differences in genetic variation within the country, and to analyze the population history of the Finns. Our results gave further support to the existence of a sharp genetic border between eastern and western Finns so far observed exclusively in Y-chromosomal variation. Both biallelic haplogroup and STR haplotype networks showed bifurcated structures, and similar clustering was evident in haplogroup and haplotype frequencies and genetic distances. These results suggest that the western and eastern parts of the country have been subject to partly different population histories, which is also supported by earlier archaeological, historical and genetic data. It seems probable that early migrations from Finno-Ugric sources affected the whole country, whereas subsequent migrations from Scandinavia had an impact mainly on the western parts of the country. The contacts between Finland and neighboring Finno-Ugric, Scandinavian and Baltic regions are evident. However, there is no support for recent migrations from Siberia and Central Europe. Our results emphasize the importance of incorporating Y-chromosomal data to reveal the population substructure which is often left undetected in mitochondrial DNA variation. Early assumptions of the homogeneity of the isolated Finnish population have now proven to be false, which may also have implications for future association studies.

Calcium:magnesium ratio in local groundwater and incidence of acute myocardial infarction among males in rural Finland

Several epidemiologic studies have shown an association between calcium and magnesium and coronary heart disease mortality and morbidity. In this small-area study, we examined the relationship between acute myocardial infarction (AMI) risk and content of Ca, Mg, and chromium in local groundwater in Finnish rural areas using Bayesian modeling and geospatial data aggregated into 10 km times symbol 10 km grid cells. Data on 14,495 men 35-74 years of age with their first AMI in the years 1983, 1988, or 1993 were pooled. Geochemical data consisted of 4,300 measurements of each element in local groundwater. The median concentrations of Mg, Ca, and Cr and the Ca:Mg ratio in well water were 2.61 mg/L, 12.23 mg/L, 0.27 microg/L, and 5.39, respectively. Each 1 mg/L increment in Mg level decreased the AMI risk by 4.9%, whereas a one unit increment in the Ca:Mg ratio increased the risk by 3.1%. Ca and Cr did not show any statistically significant effect on the incidence and spatial variation of AMI. Results of this study with specific Bayesian statistical analysis support earlier findings of a protective role of Mg and low Ca:Mg ratio against coronary heart disease but do not support the earlier hypothesis of a protective role of Ca.

Subpopulation difference scanning: a strategy for exclusion mapping of susceptibility genes

BACKGROUND

Association mapping is a common strategy for finding disease-related genes in complex disorders. Different association study designs exist, such as case-control studies or admixture mapping.

METHODS

We propose a strategy, subpopulation difference scanning (SDS), to exclude large fractions of the genome as locations of genes for complex disorders. This strategy is applicable to genes explaining disease incidence differences within founder populations, for example, in cardiovascular diseases in Finland.

RESULTS

The strategy consists of genotyping a set of markers from unrelated individuals sampled from subpopulations with differing disease incidence but otherwise as similar as possible. When comparing allele or haplotype frequencies between the subpopulations, the genomic areas with little difference can be excluded as possible locations for genes causing the difference in incidence, and other areas therefore targeted with case-control studies. As tests of this strategy, we use real and simulated data to show that under realistic assumptions of population history and disease risk parameters, the strategy saves efforts of sampling and genotyping and most efficiently detects genes of low risk--that is, those most difficult to find with other strategies.

CONCLUSION

In contrast to admixture mapping that uses the mixing of two different populations, the SDS strategy takes advantage of drift within highly related subpopulations.

Concepts of risk in dental public health

The purpose of this paper is to review the concepts of risk as we use them today in dental public health practice, and to suggest that we should broaden our view of risk. Use of terms like risk factor in the literature can be quite vague, and it is recommended that a clear definition of that and related terms be adhered to. A broader view of risk in dental research would take in the concepts of social determinants of health and population health. While some progress has been made in our understanding of these issues, better knowledge would give the public health administrator more readily available information to use in program planning. The skewed distribution of caries in the high-income countries has led to the emergence of targeted prevention programs toward those considered to be at high risk. In public health programs, targeting at the individual level is not practical: the risk assessment methods are not yet sufficiently precise, and even when individuals are identified there are practical problems with schools and with the children themselves. (For private practice, however, high-risk child patients can be identified as those with at least one approximal lesion in permanent teeth.) For public health purposes, an argument is made for geographic targeting, i.e. identification of areas of social deprivation where whole schools or school districts can be targeted. Geographic targeting is something between individual targeting and whole-population approaches. Ideally, geographic targeting would supplement population measures like water fluoridation and dental health education. Examples of geographic targeting from Ohio and New York are presented as illustrations.

Childhood growth and future development of psychotic disorder among Helsinki high-risk children

BACKGROUND

The Helsinki High-Risk (HR) Study is a follow-up study of offspring (born between 1960 and 1964) of all females treated for schizophrenia spectrum disorders in mental hospitals in Helsinki before 1975, and controls.

AIM

To compare childhood growth among HR and control children, and to determine if any patterns in childhood growth predict later development of psychotic disorders within the HR group.

METHODS

We accessed growth information from childhood health cards, which we obtained for 114 HR and 53 control offspring. The growth of HR children was compared with that of control children. Within the HR group, we investigated whether any association existed between childhood growth patterns and morbidity from psychotic disorders using logistic regression models.

RESULTS

The HR girls were shorter than controls at birth (p=0.030), but this disparity vanished by age 7. In contrast, HR boys were only slightly shorter at birth than controls, but the height difference increased with age, being statistically significant at 10 years (p=0.020). Among HR children, the combination of being in the lowest tertile for ponderal index at birth but in the highest tertile for BMI at 7 years predicted later development of schizophrenia (OR 22.8, 95% CI 2.0, >100, p=0.040).

CONCLUSIONS

Catch-up growth increases the risk of schizophrenia among offspring of mothers with psychotic disorder. Whether this is an independent risk factor or merely a reflection of some other risk factors needs further research.

Liver echogenicity: relation to systemic blood pressure and other components of the metabolic syndrome

We studied the impact of liver echogenicity among other potential predictors of systemic blood pressure (BP) and the metabolic syndrome. 38 persons (32 males, six females, aged 29 to 66) had their liver echogenicities scored, BPs measured and standard serum laboratory tests studied. There was a significant correlation between both systolic (r=0.438, p=0.006) and diastolic (r=0.498, p=0.001) BP and liver echogenicity. Liver echogenicity was the strongest predictor for systolic BP and the second strongest (after body mass index, BMI) for diastolic BP. Body height may modify the relation between liver echogenicity and systolic BP. Liver echogenicity also correlated significantly with BMI (r=0.527, p=0.001), serum triglycerides (r=0.472, p=0.003) and, to a lesser degree, with serum total cholesterol (r=0.305, p=0.066). Incidentally found increased liver echogenicity should alert the US performer and the clinician reading the report on the possibility of elevated BP or other features of the metabolic syndrome.

Early Life Factors and Blood Pressure at Age 31 Years in the 1966 Northern Finland Birth Cohort

Data on the birth weight-blood pressure relationship are inconsistent. Although an inverse association has been suggested in several large studies, interpretation is complicated by publication and other biases. Few data are available on the relationship between other early growth measures and blood pressure. We examined the shape and size of association between determinants of fetal growth, size at birth, growth in infancy, and adult systolic and diastolic blood pressure at 31 years in the prospective northern Finnish 1966 birth cohort of 5960 participants. Birth weight, birth length, gestational age, ponderal index, and birth weight relative to gestational age showed a significant inverse association with blood pressure at age 31. Rapid growth in infancy ("change-up") was positively associated with blood pressure. Adjusted regression coefficients for birth weight indicated systolic/diastolic blood pressure lower by -1.7 (95% confidence interval [CI], -2.5, -1.0)/-0.7 (95% CI, -1.4, -0.02) mm Hg for 1 kg higher birth weight. The significant inverse association between birth weight and systolic blood pressure persisted without adjustment for adult body mass index for males. Among females, gestational age showed a stronger association with blood pressure than birth weight: gestational age higher by 7 weeks (equivalent to an average of 1 kg higher birth weight) among singletons associated with -2.9 (95% CI, -4.7, -1.1) mm Hg lower systolic blood pressure. Our results support the concept that birth weight, other birth measures, and infant growth are important determinants of blood pressure and hence cardiovascular disease risk in later life.

Impact of age on cardiovascular risk: implications for cardiovascular disease management

Cardiovascular disease (CVD) represents a major global healthcare problem. The prevalence of this condition increases with age. As many countries around the world are experiencing an increase in the proportion of elderly people in the population, this raises serious issues for cardiac and cerebrovascular disease prevention and management. A wealth of data has established smoking, dyslipidemia, hypertension and type 2 diabetes as major risk factors for cardiac and cerebrovascular events. This article reviews the evidence that links these metabolic risk factors with an increased risk of complications, and assesses the data concerning how risk changes with age. This review also focuses on how these conditions can be optimally managed and whether treatment outcomes are affected by age. The current status of research is assessed and issues which remain to be resolved are highlighted.

Geochemistry of ground water and the incidence of acute myocardial infarction in Finland

STUDY OBJECTIVE

To examine the association of spatial variation in acute myocardial infarction (AMI) incidence and its putative environmental determinants in ground water such as total water hardness, the concentration of calcium, magnesium, fluoride, iron, copper, zinc, nitrate, and aluminium.

DESIGN

Small area study using Bayesian modelling and the geo-referenced data aggregated into 10 km x 10 km cells.

SETTING

The population data were obtained from Statistics Finland, AMI case data from the National Death Register and the Hospital Discharge Register, and the geochemical data from hydrogeochemical database of Geological Survey of Finland.

PARTICIPANTS

A total of 18 946 men aged 35-74 years with the first AMI attack in the years 1983, 1988, and 1993.

MAIN RESULTS

One unit (in German degree degrees dH) increment in water hardness decreased the risk of AMI by 1%. Geochemical elements in ground water included in this study did not show a statistically significant effect on the incidence and spatial variation of AMI, even though suggestive findings were detected for fluoride (protective), iron and copper (increasing).

CONCLUSIONS

The results of this study with more specific Bayesian statistical analysis confirm findings from earlier observations of the inverse relation between water hardness and coronary heart disease. The role of environmental geochemistry in the geographical variation of the AMI incidence should be studied further in more detail incorporating the individual intake of both food borne and water borne nutrients. Geochemical-spatial analysis provides a basis for the selection of areas suitable for such research.

The 21-year follow-up of the Cardiovascular Risk in Young Finns Study: risk factor levels, secular trends and east-west difference

OBJECTIVES

The Cardiovascular Risk in Young Finns Study is an on-going multicentre study of atherosclerosis precursors in Finnish children and young adults. We have collected risk factor data in the 21-year follow-up performed in 2001. The aims of this analysis were to examine the levels, secular trends and east-west difference in risk factors amongst young adults.

DESIGN

Population based follow-up study.

SUBJECTS

A total of 2283 participants aged 24-39 years in 2001 (63.5% of the original cohort).

MAIN OUTCOME MEASURES

Levels of serum lipids, apolipoproteins, blood pressure and smoking.

RESULTS

The mean serum total cholesterol, low density lipoprotein cholesterol, high density lipoprotein (HDL) cholesterol and triglyceride concentrations in 24-39-year-old adults were 5.16, 3.27, 1.29 and 1.34 mmol L(-1), respectively. Total cholesterol (5.21 vs. 5.12 mmol L(-1), P = 0.046), HDL cholesterol (1.31 vs. 1.28 mmol L(-1), P = 0.027), systolic blood pressure (118 vs. 115 mmHg, P < 0.0001) and diastolic blood pressure (72 vs. 70 mmHg, P < 0.0001) were higher in subjects originating from eastern Finland compared with those from western Finland. Significant secular trends between 1986 and 2001 in 24-year-old subjects (n = 783) included an increase in serum triglycerides and body mass index (BMI), a decrease in blood pressure and HDL cholesterol and a modest 5% decrease in total cholesterol levels.

CONCLUSIONS

During the past 15 years, BMI and triglyceride levels have increased in young adults in Finland. At the same time, the reduction in cholesterol concentration has been slow. Consistent with persistent regional differences in cardiovascular morbidity within Finland, our data demonstrate significant differences in the levels of cardiovascular risk factors between subjects originating from eastern and western Finland.

Is the association between short stature and myocardial infarction explained by childhood exposures--a population-based case referent study (SHEEP)

AIMS

This study was undertaken to examine the association between short stature and acute non-fatal myocardial infarction and to analyse causal mechanisms related to height with a focus on childhood risk factors.

METHOD

The SHEEP (Stockholm Heart Epidemiology Program) is a population-based case-referent study. The outcome was incident first events of myocardial infarction. The study base included all Swedish citizens aged 45 to 70, who lived in Stockholm County during 1992-94. This analysis is based on 967 male cases, 412 female cases and 1696 referents. Exposure information was obtained through questionnaires, interviews, health examinations, and obstetric records.

RESULTS

Adult height was inversely related to myocardial infarction. The odds ratio for men in the shortest quartile (< 173 cm) compared with the tallest was 1.78 (95% CI: 1.39, 2.28). For women the corresponding odds ratio in the shortest quartile (<159 cm) was 1.86 (95% CI: 1.28, 2.71). Height was also inversely associated with fetal growth and indicators of material resources during childhood. Within each social class of origin short stature was associated with number of siblings, lack of higher education, and absence of upward social mobility. Adjustment for childhood risk factors decreased the excess relative risk of short stature with around 25%. Adult social, behavioural, and biological risk factors could not explain the association. The findings were similar for men and women.

CONCLUSION

Height is associated with many risk factors of myocardial infarction, which increase the risk of disease through many different causal pathways. Childhood exposures have no dominant role in explaining the association between short stature and myocardial infarction.

The association between body height and coronary heart disease among Finnish twins and singletons

OBJECTIVE

An inverse association between body height and the incidence of coronary heart disease (CHD) has been observed. However, the mechanisms behind this association are still largely unknown. We will examine the role of genetic and familial factors behind the association in a large twin data set.

DESIGN AND SETTING

The data were derived from the Finnish Twin cohort including 2438 singletons, 4073 monozygotic (MZ) twins, and 9202 dizygotic (DZ) twins aged 25-69 years at baseline in 1976. Incident CHD cases were derived from hospital discharge data and cause of death data between 1977 and 1995. Cox regression analysis and conditional logistic regression analysis were used.

RESULTS

In population-level analyses no differences in the general risk of CHD between zygosity groups were found. The association between body height and CHD was similar between sexes and zygosity groups. When men and women in all zygosity groups were studied together an increased risk of CHD was found only among the shortest quartile (hazard ratio [HR] = 1.34, 95% CI: 1.14-1.57). Among the twin pairs discordant for CHD a suggestive increased risk for the shorter twin was seen among DZ twins (odds ratio [OR] = 1.19, 95% CI: 0.95-1.48) when men and women were studied together.

CONCLUSION

An inverse association between body height and CHD was broadly similar between sexes and twin zygosity groups and was associated with short stature. Among discordant twin pairs we found a weak association among DZ twins but not MZ twins. This may suggest the role of genetic liability behind the association between body height and CHD.

Geographical variation in the incidence of acute myocardial infarction in eastern Finland--a Bayesian perspective

BACKGROUND

Large geographical variation in the incidence and mortality of cardiovascular disease (CHD) has been repeatedly reported in Finland with persistent difference between east and west. We undertook this study to estimate the geographical distribution of Acute Myocardial Infarction (AMI) incidence in the high-risk province of North Karelia and in the province of Kuopio.

METHODS

Data on men aged 25-64 years with first event of acute myocardial infarction (AMI) were obtained from the FINMONICA AMI register, which recorded detailed information of AMI events during the period 1983 to 1992. The geographical pattern of AMI incidence was studied in two five-year periods 1983 to 1987 and 1988 to 1992 separately in 10 km x 10 km grid cells employing the Geographical Information System (GIS) and a Bayesian hierarchical approach.

RESULTS

In both periods Bayesian modeling revealed a geographical pattern of AMI incidence and high risk (probability that incidence exceeds the observed mean incidence) in the remote rural areas.

CONCLUSIONS

Detection of high-risk areas in both provinces showed that underlying environmental and/or genetic risk factors of AMI are not evenly distributed within the province but enriched in certain geographical non-administratively defined locations in eastern Finland.

Body height is associated with decreased long-term stroke but not coronary heart disease mortality?

BACKGROUND AND PURPOSE

There is disagreement whether shorter persons suffer increased rates of coronary heart disease (CHD) or stroke. Potential mechanisms for such associations are not well understood. We used findings from a cohort study, in which 10 000 Israeli men were followed up, to examine the associations between stature and fatal CHD as well as fatal stroke.

METHODS

The cohort was composed of 10 059 men aged > or = 40 years who were tenured civil servants or municipal employees. They were followed up for mortality over 23 years (1963 to 1986), for a total of 203 452 person-years of follow-up. We divided men by their height, as measured in the baseline (1963) examinations, into quartiles (< or = 162 cm, 163 to 167 cm, 168 to 171 cm, and > or = 172 cm).

RESULTS

During the follow-up period, 1098 men died of CHD, and 364 men died of stroke. Height and weight had been measured for 10 034 men, including all but 1 of the deceased. In contrast to the finding of little variation of CHD death rates between different quartiles of body height, a clear significant pattern of declining stroke mortality (slightly reduced by age adjustment) was observed with increasing body height, with rates of 46, 36, 33, and 29 per 1000 men with increasing height quartiles, respectively (P=0.002 for linear trend). The estimated age-adjusted hazard risk of stroke mortality associated with a 5-cm decrement in height was 1.13 (95% CI 1.04 to 1.22). The respective risk associated with being at the shortest quartile versus the tallest one was 1.54 (95% CI 1.13 to 2.10). Adjustment for socioeconomic status, a predictor of stroke in this cohort, for antihypertensive therapy and for established predictors of stroke (blood pressure, smoking, and diabetes) did not alter these findings.

CONCLUSIONS

Height, a potential strong indicator of nutritional status, may be inversely associated with the long-term incidence of fatal stroke in a way that remains to be elucidated.

Human population genetics: lessons from Finland

A population of about 5 million at the northern corner of Europe is unlikely to arouse the attention of the human genetics community, unless it offers something useful for others to learn. A combination of coincidences has finally made this population one that, out of proportion for its size, has by example shaped research in human disease genetics. This chapter summarizes advances made in medical genetics that are based on research facilitated by Finland's population structure. The annotation of the human genome for its polymorphism and involvement in disease is not over; it is, therefore, of interest to assess whether genetic studies in populations such as the Finnish might help in the remaining tasks.

Regional differences in the incidence of rheumatoid arthritis in Finland in 1995

OBJECTIVE

To investigate regional differences in the incidence of rheumatoid arthritis (RA).

METHODS

Those subjects entitled to receive drug reimbursement for chronic inflammatory joint diseases in 11/21 central hospital districts (population base about 1.8 million adults) in Finland during 1995 were studied. The incidence rates from these central hospital districts were compared.

RESULTS

A total of 1213 subjects were entitled to drug reimbursement for chronic inflammatory joint disease which had started at the age of 16 or over. Of these, 598 subjects satisfied the American Rheumatism Association 1987 criteria for RA. The age adjusted incidence of RA was 31.7/100 000 (95% CI 29.2 to 34.4) and varied significantly (p<0.001) among the central hospital districts, ranging from 16.3 to 44.8/100 000.

CONCLUSION

There are regional differences in the incidence of RA. The reasons for these are probably environmental rather than genetic.

Two loci on chromosomes 2 and X for premature coronary heart disease identified in early- and late-settlement populations of Finland

Coronary heart disease (CHD) is a complex disorder constituting a major health problem in Western societies. To assess the genetic background of CHD, we performed a genomewide linkage scan in two study samples from the genetically isolated population of Finland. An initial study sample consisted of family material from the northeastern part of Finland, settled by a small number of founders approximately 300 years ago. A second study sample originated from the southwestern region of Finland, settled approximately 2,000 years ago. Families were ascertained through probands exhibiting premature CHD, defined as >50% stenosis of at least two coronary arteries at a young age, as verified by coronary angiography. Both study samples and the pooled data set provided evidence for linkage in two chromosomal regions. A region on chromosome 2q21.1-22 yielded two-point LOD scores of 3.2, 1.9, and 3.7, in the affected sib-pair (ASP) analyses of the northeastern, southwestern, and pooled study samples. The corresponding multipoint maximum-likelihood scores (MLSs) for these three study samples were 2.4, 1.3, and 3.0. In addition, a region on chromosome Xq23-26 resulted in two-point LOD scores of 1.9, 3.5, and 2.9 and in multipoint MLSs of 3.4, 3.1, and 2.5, respectively. In conclusion, this study identifies two loci likely to contribute to premature CHD: one on chromosome 2q21.1-22 and another on chromosome Xq23-26.

Acute myocardial infarction and Helicobacter pylori seropositivity

Infectious agents including Helicobacter pylori, have been linked to coronary heart diseases on epidemiological and pathogenetic grounds. Classical risk factors fail to explain all the epidemiological variations of the disease. Our aim was to investigate the association of acute myocardial infarction with Helicobacter pylori infection in a case-control study by comparing a group of male patients with a control group of blood donors matched for sex and age. We investigated the classical cardiovascular risk factors in all patients. We studied 44 consecutive male patients, aged 40-65 years, admitted for acute myocardial infarction to the Coronary Care Unit at Novi Ligure Hospital in northern Italy. Helicobacter pylori infection was assessed by measurement of antibodies (IgG) against Helicobacter pylori in blood. Volunteer blood donors attending Molinette Hospital Blood Bank in Turin, northern Italy served as controls. Among the patients we investigated the presence of hypertension, cholesterol and glucose levels in serum, fibrinogen in plasma, smoking habits, and social class. Helicobacter pylori infection was present in 34 of 44 (77%) patients and in 183 of 310 (59%) controls (P<0.05); the odds ratio was 2.36 (95% confidence interval 1.08-5.31). Classical cardiovascular risk factors did not differ among patients with and without Helicobacter pylori infection. In conclusion, patients with acute myocardial infarction had a significantly higher prevalence of Helicobacter pylori infection than the control population. The classical risk factors for cardiovascular diseases were equally distributed among patients irrespective of their Helicobacter pylori status.