Regional variations in mortality from ischaemic heart and cerebrovascular disease in Britain

Maternal nutrient restriction alters renal development and blood pressure regulation of the offspring

Studies have shown that the risk of hypertension in adulthood can be affected by the in utero environment. It is established that hypertension is linked to compromised kidney function and that factors affecting organogenesis can increase the risk of later disease. Prostaglandins (PG) and growth factors are known to play an important role in regulating kidney function and renal organogenesis. The extent, however, to which global energy restriction (where all nutrients are reduced) of the mother can programme later blood pressure control or renal PG and growth factor status is unknown. A study is described that aimed to examine the long-term effects of maternal nutrient restriction (NR) and elucidate their relationship with compromised kidney development. First, it was necessary to establish animal models. A sheep model of 50% NR during specific stages of gestation was used to investigate fetal renal development, whilst a rat model of 50% NR throughout pregnancy was used to investigate postnatal kidney development and adult functioning. Molecular analysis has shown that expression of the growth hormone–insulin-like growth factor (GH–IGF) axis is affected by NR in the fetal sheep kidneys, and that changes are dependent on the timing of NR and whether the fetus is a singleton or a twin. Analysis of the kidneys from the rat model has shown nutritional differences in the expression of PG receptors and the enzymes responsible for PG synthesis and degradation that persist into adulthood. In conclusion, NR does affect the GH–IGF and PG axes, and these changes may be important in the nutritional programming of renal functioning and adult blood pressure control.

Metropolitan and non-metropolitan trends in coronary heart disease mortality within Appalachia, 1980-1997

OBJECTIVES

In this article, we report on metropolitan and non-metropolitan trends in coronary heart disease (CHD) mortality within the Appalachian Region for the period 1980 to 1997. We hypothesized that trends in CHD mortality would be less favorable in non-metropolitan populations with diminished access to social, economic, and medical care resources at the community level.

METHODS

Our study population consisted of adults aged 35 years and older who resided within the 399 counties of the Appalachian Region between 1980 and 1997. We examined mortality trends for sixteen geo-demographic groups, defined by gender, age, race, and metropolitan status of county of residence. For each geo-demographic group, we calculated annual age-adjusted CHD mortality rates. Line graphs of these temporal trends were created, and log-linear regression models provided estimates of the average annual percent change in CHD mortality from 1980 to 1997. Data on social, economic, and medical care resources for metropolitan vs. non-metropolitan counties were also analyzed.

RESULTS

Rates of CHD mortality were consistently higher in non-metropolitan areas compared with metropolitan areas for blacks of all ages and for younger whites. CHD mortality declined among almost all geo-demographic groups, but rates of decline were slower among non-metropolitan vs. metropolitan residents, blacks vs. whites, women vs. men, and older vs. younger adults. Non-metropolitan areas had fewer socioeconomic and medical care resources than metropolitan areas in 1990.

CONCLUSIONS

Appalachia, particularly non-metropolitan Appalachia, needs policies and programs that will enhance both primary and secondary prevention of CHD, and help diminish racial inequalities in CHD mortality trends.

Disparities in premature coronary heart disease mortality by region and urbanicity among black and white adults ages 35-64, 1985-1995

OBJECTIVES

Regional and urban-rural disparities in premature coronary heart disease (CHD) mortality were evident in the US as early as 1950. Recent favorable trends at the national level may obscure less favorable outcomes for certain regions and localities. The authors examined trends in premature CHD mortality for 1985-1995 for black and white adults ages 35-64 years for four categories of urbanicity in two regions of the US (South and non-South).

METHODS

All counties in the US (excluding Alaskan counties) were grouped by urbanicity and region. Annual age-adjusted CHD mortality rates were calculated for adults ages 35-64 by racial category (African American or white) and gender for each geographic area for the years 1985- 1995. Loglinear regression models were used to estimate average annual percent declines in mortality for each of 28 geo-demographic groups. Data were also collected on selected socioeconomic resources by urbanicity for the non-South (excluding Alaska) and South.

RESULTS

For both white and black adults ages 35-64, the highest rates of premature CHD mortality and slowest mortality declines were observed in the rural South. For white men and women, marked disparities in premature CHD mortality across categories of urbanicity were noted in the South but not outside the South. Unexpectedly high rates of premature CHD mortality were observed for African Americans in major metropolitan areas outside the South despite favorable levels of socioeconomic resources.

CONCLUSIONS

Disparities in premature CHD mortality by region and urbanicity appear to have widened between 1985 and 1995. Residents of the rural South had the highest rates of premature CHD mortality, and rural communities in the South face significant barriers to effective heart disease prevention and control.

Trends in mortality from stroke in Scotland, 1950-1986

The Scottish Registrar General's Annual Reports have been used to study trends in mortality from stroke in Scotland during 1950-1986 in those aged 45 to 74. In 1950 the age-adjusted mortality rate was 347.4 per 100,000 population for men and 360.8 for women, falling to 199.6 for men and 155.8 for women in 1986. This downward trend has increased from 1976 for males. The average annual decline in age-adjusted mortality from stroke over the 37-year period was 4.0 per 100,000 in males and 5.5 in females. This reduction in death rates was proportionally higher for women compared with men in all age groups over 55 years. As with cardiovascular deaths, mortality from stroke was lower in the east than in the central region and west of Scotland. The reduction in mortality resulted in a substantial 'saving' of lives, estimated at 12,500 between 1980 and 1984.

Are geographical differences in cardiovascular mortality due to morbidity differences or to methodological differences? The project "myocardial infarction in Mid-Sweden"

Geographical variations in cardiovascular mortality have been reported from Mid-Sweden. IHD mortality for men aged 45-64 was 60% higher in the western part than in the east. Mortality from stroke for men aged 45-74 was 73% higher on the west. Similar differences were found for women. One possible explanation could be that there are no incidence differences but that the mortality differences are due to different survival rates or to differences certifying the cause of death. These two possible explanations were tested in this study. Data for all patients hospitalised during the 10-year period 1972-1981 for myocardial infarction or stroke in a high mortality area, the County of Värmland in the west, and a low mortality area, the County of Uppsala in the east, were collected. In addition, a substudy was performed where the basis for the death certificate diagnosis was studied. The western area generally had a higher case fatality rate than the eastern. However, a larger proportion of the deaths the eastern area, occurred outside hospital, so that the net effect would be that the differences found were not large enough to explain the mortality differences. The autopsy rate in the western part was lower than in the east but since a larger proportion of the deaths occurred in hospital the rank order for IHD and stroke mortality between east and west was the same whether all IHD or stroke deaths were counted or only those considered the most well documented.

Unemployment, socioenvironmental factors, and coronary heart disease in Scotland

Scotland, which has one of the highest death rates in the world from coronary heart disease, also has considerable regional variation in mortality from this cause. The relation between standardised mortality ratios for coronary deaths (1979-83) for 56 local government districts and a range of socioeconomic factors from the 1981 Census as well as climatic factors and water hardness were investigated. Strong associations were seen with several measures of social disadvantage, the strongest being with percentage of male unemployment. A fitted multiple regression model with mortality from coronary heart disease in men found independent effects of two social variables (percentage male unemployment and percentage social class III-V) and one climatic factor (rainfall). The model explained much (73%) of the geographical variation in mortality from coronary heart disease, but part of the geographical pattern, in particular some of the east-west gradient in mortality, remained unexplained by it. Explanations for the geographical variation and the association with economic factors are currently being sought in terms of individual risk factors in a large screening study, the Scottish Heart Health Study.

Prevalence of ischaemic heart disease in middle aged British men

The prevalence of ischaemic heart disease was determined by an administered questionnaire and electrocardiography in 7735 men aged 40-59 years drawn at random from general practices in 24 British towns. Overall, one quarter of these men had some evidence of ischaemic heart disease on questionnaire or electrocardiogram or both. On questionnaire, 14% of men had possible myocardial infarction or angina, with considerable overlap of the two syndromes. The prevalence of possible myocardial infarction combined with angina and of definite angina only showed a fourfold increase over the age range studied. Electrocardiographic evidence of ischaemic heart disease (definite or possible) was present in 15% of men, there being myocardial infarction in 4.2% and myocardial ischaemia in 10.3%. Electrocardiographic evidence of myocardial infarction increased fourfold over the age range studied. There was considerable overlap of questionnaire and electrocardiographic evidence of ischaemic heart disease. Nevertheless, more than half of those with possible myocardial infarction combined with angina had no resting electrocardiographic evidence of ischaemic heart disease, and half of those with definite myocardial infarction on electrocardiogram had no history of chest pain at any time. This national population based study strongly suggests that the prevalence of ischaemic heart disease in middle aged British men is greater than has been indicated by previous studies based on occupational groups.

Geographical patterns of heart disease in the Northeastern United States

A 49-county region surrounding the urban corridor from New York through New Jersey to Philadelphia was the focus of an investigation of the spatial patterns of mortality from four types of heart disease: major cardiovascular, acute ischemic, chronic ischemic and cerebrovascular. The data used were age-adjusted mortality rates for white males and white females for the period 1968-1972. Central to the research was interest in the existence of county clusters with similar rates, high and low risk areas and possible associations of mortality rates with environmental and socioeconomic conditions. The tasks completed in this first phase of a projected multi-phase project led to the identification of four country clusters within the region. High major cardiovascular rates appear to make the Southern New Jersey cluster a high risk zone. In contrast, a Central Corridor cluster has relatively low rates for all the diseases. No clear pattern was in evidence for the Northwestern Periphery cluster. Finally, a stark contrast between acute and chronic ischemic rates appeared in the Urban Spur. The next step in this research will be to search for either consistency or deviation from these patterns in the 1973-1976 period. A risk factor data set will be created to analyze the patterns in greater detail.

Platelet functions in relation to diet and serum lipids in British farmers

Coagulation and platelet aggregation induced by thrombin, ADP, adrenaline, and collagen were studied in three contrasted groups, each of 20 to 22 middle-aged male farmers. Serum lipids were similar in the three groups. In the west of Scotland group, however, platelet reactivity was significantly greater than in the east of Scotland. This was associated with a dietary intake, evaluated by three different techniques, higher in saturated fat but also lower in polyunsaturated fat and alcohol. Platelet function in the southern England group also correlated with dietary fats and in addition inversely with calcium intake. On an individual basis in the 63 farmers, all the platelet function tests were significantly correlated with the intake of saturated fat regulated by that of calcium and alcohol. The dietary effects on platelets appear to be mediated by the fatty acid composition of plasma lipids and of platelet phospholipids. In that fraction, the fatty acids 20:3 omega 9, 22:3 omega 9 and 20:4 were the most closely related to the platelet function tests. the trienoic acid 20:3 omega 9, identified with essential fatty acid deficiency, was also correlated with the intake of saturated fat and calcium. In this study, platelet functions were more dependent upon the dietary factors associated with coronary heart disease such as saturated fats, calcium, and alcohol than upon serum lipids.

British Regional Heart Study: cardiovascular risk factors in middle-aged men in 24 towns

The British Regional Heart Study seeks to define risk factors for cardiovascular disease, to examine their interrelationships, and to explain the geographic variations in cardiovascular disease in Britain. A clinical survey of men aged 40-59 in 24 British towns was carried out and preliminary data from the survey analysed. On a town basis cardiovascular mortality was associated with mean systolic blood pressure and the prevalence of heavy cigarette smoking and heavy alcohol consumption. No such association was seen for body mass index or mean serum total cholesterol or high-density-lipoprotein cholesterol concentration. Cigarette smoking and alcohol intake and, to a less degree, systolic blood pressure were related to the social class (percentage of manual workers) of a town, and these factors may determine to some extent the increased risk of cardiovascular disease in manual workers. Blood pressure in individual subjects was affected predominantly by age, body mass index, and alcohol intake. Body mass index appeared to affect blood pressure to a greater extent than alcohol intake and did so with a consistent and positive linear trend. Nevertheless, the differences between towns in mean blood pressure readings appeared to be more closely associated with variations in the prevalence of heavy drinking than with variations in body mass index. Alcohol intake and body mass index explained only a part of the striking differences between towns in mean blood pressure readings, and some important "town"factors remained unexplained.

Smoking and health: the association between smoking behaviour, total mortality, and cardiorespiratory disease in west central Scotland

The relationship of smoking to total mortality and to the prevalence of cardiorespiratory symptoms has been studied in three prospective surveys in west central Scotland in which 18 786 people attended a multiphasic screening examination. The prevalence of respiratory symptoms, and to a lesser extent cardiovascular symptoms, increased with the number of cigarettes smoked, with inhalation, and with a younger age of starting to smoke. A lower prevalence of respiratory symptoms in both sexes was observed in smokers of filter cigarettes than in smokers of plain cigarettes, and in those who smoked cigarettes with lower tar levels, irrespective of whether these were filtered or plain. In general, the relationships found between smoking and mortality were similar to those reported by other workers. Current cigarette smokers had a death rate from all causes which was twice that of those who had never smoked. No difference was found between the mortality rates of smokers of plain and filter cigarettes.