Secular changes in blood pressure in childhood, adolescence and young adulthood: systematic review of trends from 1948 to 1998

One plausible reason for the decline in cardiovascular disease (CVD), and in particular stroke, in the last century is population reductions in blood pressure. Blood pressure tracks from childhood into adulthood, and early-life blood pressure is associated with increased cardiovascular risk but few studies have reported on blood pressure trends among young individuals who are free of CVD and not taking antihypertensive medication. Knowledge of such trends may improve understanding of the causes of hypertension and enhance prevention. We report that declines in blood pressure have been taking place in high-income countries in 5 to 34-year-olds of both sexes and from a range of ethnic groups for at least the last 50 years, indicating that exposures acting in early life are important determinants of blood pressure. Possible explanations for these favourable trends include improvements in early-life diet and there is also intriguing evidence suggesting that blood pressure may be programmed by sodium intake in infancy. Occurring throughout the blood pressure distribution, these trends may have made important contributions to declining CVD rates. There may therefore be scope for intervening in early life to prevent high blood pressure in adulthood, and the downward trends reported in several recent studies suggest that the prevalence of adult hypertension and cardiovascular risk will continue to decline. However, persisting high rates of CVD in the developed world, the impending CVD epidemic in developing countries, along with increasing childhood obesity, and the possibility that favourable blood pressure trends may be plateauing point to the need for enhanced measures to control blood pressure, and for further research to improve understanding of its determinants.

Treatment of oral cancer: the need for defined protocols and specialist centres. variations in the treatment of oral cancer

The authors of this study aimed to identify treatment philosophies for oral cancer within the west of Scotland and to investigate any survival differences associated with the various treatment options by means of a retrospective review of case notes and cancer registry data. All patients with squamous cancer of the tongue or floor of the mouth were identified from the West of Scotland Cancer Registry for the period 1984-1990. A total of 206 patients were available for study. Five different treatment protocols were identified: 5% of patients underwent biopsy only, 16% biopsy plus radiotherapy, 11% excisional biopsy, 25% radical surgery, and 42% radical surgery plus radiotherapy. Tumour staging by the TNM classification was an important factor that determined outcome. When adjusting for T stage and nodal involvement, there was a significant effect of treatment protocol on both the disease-free period (P < 0.001) and on survival (P < 0.001). The treatment options were used differently by individual clinicians and were related to stage of the disease. One hundred and forty-four (70%) of the patients were treated by a single combined head and neck unit based within the plastic surgery unit at Canniesburn Hospital. The remaining 62 were treated in 13 different units throughout the west of Scotland. For those not treated in the combined head and neck unit, the increased hazard for recurrence was 1.43 (95% confidence interval (CI) 1.01-2.02), and the increased hazard ratio for death was 1.48 (95% CI 1.06-2.06) when adjusting for tumour stage, and nodal involvement. Treatment philosophies for oral cancer have a significant effect on outcome. There is a need to develop clearly defined protocols based on staging and site of disease. We believe that treatment should be carried out within a multidisciplinary setting in a combined head and neck cancer unit.

Association of early life factors and acute lymphoblastic leukaemia in childhood: historical cohort study

In a historical cohort study of all singleton live births in Northern Ireland from 1971-86 (n=434,933) associations between early life factors and childhood acute lymphoblastic leukaemia were investigated. Multivariable analyses showed a positive association between high paternal age (> or =35 years) and acute lymphoblastic leukaemia (relative risk=1.49; 95% confidence interval (CI)=0.96--2.31) but no association with maternal age. High birth weight (> or =3500 g) was positively associated with acute lymphoblastic leukaemia (relative risk=1.66; 95% CI=1.18--2.33). Children of mothers with a previous miscarriage or increased gestation (> or =40 weeks) had reduced risks of ALL (respective relative risks=0.49; 95% CI=0.29--0.80, and 0.67; 95% CI=0.48--0.94). Children born into more crowded households (> or =1 person per room) had substantially lower risks than children born into less crowded homes with also some evidence of a lower risk for children born into homes with three adults (relative risks=0.56; 95% CI=0.35-0.91 and 0.58; 95% CI=0.21-1.61 respectively). These findings indicate that several early life factors, including living conditions in childhood and maternal miscarriage history, influence risk of acute lymphoblastic leukaemia in childhood.

Sexual intercourse and risk of ischaemic stroke and coronary heart disease: the Caerphilly study

OBJECTIVE

To examine the relation between frequency of sexual intercourse and risk of ischaemic stroke and coronary heart disease.

DESIGN

Cohort study with 20 year follow up.

SETTING

The town of Caerphilly, South Wales and five adjacent villages.

SUBJECTS

914 men aged 45-59 years at time of recruitment in 1979 to 1983.

MAIN OUTCOME MEASURES

Ischaemic stroke and coronary heart disease, all first events and fatal events.

RESULTS

Of the 914 men studied, 197 (21.5%) reported sexual intercourse less often than once a month, 231 (25.3%) reported sexual intercourse twice or more a week, and the remaining 486 (53.2%) men fell into the intermediate category. Frequency of sexual intercourse was not associated with all first ischaemic stroke events: age adjusted odds ratios (95% CI) for intermediate and low frequency of sexual intercourse of 0.61 (0.32 to 1.16) and 0.71 (0.34 to 1.49) respectively compared with the reference category of high frequency. A graded relation with fatal coronary heart disease events was observed in events recorded up to 10 years. The age adjusted relative risk (95% CI) of fatal coronary heart disease contrasting low frequency of sexual intercourse (that is, less than monthly) with the highest group (at least twice a week) was 2.80 (1.13 to 6.96, test for trend, p=0.04) which was not attenuated by adjustment for a wide range of potential confounders. Longer follow up to 20 years showed attenuation of this risk with odds of 1.69 (95% CI 0.90 to 3.20), contrasting low frequency of sexual intercourse with the highest group.

CONCLUSIONS

The differential relation between frequency of sexual intercourse, stroke and coronary heart disease suggests that confounding is an unlikely explanation for the observed association with fatal coronary heart disease events. Middle aged men should be heartened to know that frequent sexual intercourse is not likely to result in a substantial increase in risk of strokes, and that some protection from fatal coronary events may be an added bonus.

Platelet tests in the prediction of myocardial infarction and ischaemic stroke: evidence from the Caerphilly Prospective Study

A platelet test that is predictive of myocardial infarction (MI) and/or stroke would enable the targeting of anti-platelet drugs towards high-risk patients. The predictive power of several platelet tests for MI and for stroke was examined in 2000 older men in the Caerphilly Cohort Study of Heart Disease, Stroke and Cognitive Decline. The tests were: aggregation to adenosine diphosphate (ADP) in platelet-rich plasma (PRP); aggregation to ADP in whole blood measured using an impedance method and a test of platelet aggregation induced in whole blood by high-shear flow. Around 200 MIs and 100 ischaemic strokes occurred during a 10-year follow-up. Neither primary nor secondary aggregation in PRP was predictive of MI. However, the fifth of men in whom the primary response to ADP was least, showed the highest risk of a subsequent stroke [relative odds (RO) 1.64; 95% confidence interval (CI) 1.12-2.43]. Aggregation in whole blood was not predictive of MI but, again, the fifth of men with the least platelet response showed the highest stroke incidence (RO 1.79; 95% CI 1.06-3.00). Retention of platelets in the high-shear test was not predictive of either event.

Changes in blood pressure among students attending Glasgow University between 1948 and 1968: analyses of cross sectional surveys

OBJECTIVES

To examine the changes in blood pressure over time in a cohort of young adults attending university between 1948 and 1968.

DESIGN

Cross sectional study.

SETTING

Glasgow University.

PARTICIPANTS

12 414 students aged 16-25 years-9248 men (mean age 19.9 years) and 3164 women (19.2 years)-who participated in health screening on entering university between 1948 and 1968.

MAIN OUTCOME MEASURES

Systolic and diastolic blood pressure.

RESULTS

In male students mean systolic blood pressure adjusted for age decreased from 134.5 (95% confidence interval 133.8 to 135.2) mm Hg in those born before 1929 to 125.7 (125.0 to 126.3) mm Hg in those born after 1945, and diastolic blood pressure dropped from 80.3 (79.8 to 80.8) mm Hg to 74.7 (74.2 to 75.1) mm Hg. For female students the corresponding declines were from 129.0 (127.5 to 130.5) mm Hg to 120.6 (119.8 to 121.4) mm Hg and from 79.7 (78.7 to 80.6) mm Hg to 77.0 (76.5 to 77.5) mm Hg. Adjustment for potential confounding factors made little difference to these findings. The proportion of students with hypertension declined substantially in both sexes.

CONCLUSIONS

Substantial declines in systolic and diastolic blood pressure over time were occurring up to 50 years ago in young adults who were not taking antihypertensive medication. Since blood pressure tracks into adult life, the results of the cross sectional comparisons suggest that factors acting in early life may be important in determining population risk of cardiovascular disease. Changes in such factors may have made important contributions to the decline in rates of cardiovascular diseases, particularly stroke, seen in developed countries during the past century.

Age at menarche: secular trends and association with adult anthropometric measures

BACKGROUND

Age at menarche has been used as a marker of environmental conditions during childhood. Previous work has shown trends of decreasing age at menarche throughout the 19th century, but reported trends in the 20th century have been less consistent. The nature of the relationship between age at menarche and adult life anthropometric measures may be important in understanding the importance of this measure on disease in later life.

AIM

To establish whether mean age at menarche changed during the first half of the 20th century, and to determine the nature of associations between age at menarche and anthropometric measures in young adulthood.

SUBJECTS AND METHODS

3433 female students, who were born between 1919 and 1952 and who attended health checks at the student health service of the University of Glasgow between 1948 and 1968.

RESULTS

Mean age at menarche decreased from 13.2 years in the earliest born to 12.5 years in the latest born students. These results were not explained by changes in socio-demographic factors. Menarcheal age was positively associated with height and negatively associated with weight and BMI, results independent of socio-demographic and behavioural factors.

CONCLUSIONS

The falling age at menarche described here may be related to nutritional influences in the first half of the 20th century. The influence of menarche on BMI in early adulthood may have important health consequences.

The incidence and aetiology of stroke in the Caerphilly and Speedwell Collaborative Studies I: methods and incidence of events

Stroke mortality and morbidity remain high despite downward trends in incidence and case fatality. Population-based longitudinal studies which include collection of risk factor data are required for a better understanding of stroke aetiology. From a representative cohort of men from South Wales and South-west England, followed up for a median of 17 y, details of possible cerebrovascular events were collected from questionnaires, hospital admission data, general practitioner records, death certificates, radiology records and post-mortem reports. Radiology records, and strokes and transient ischaemic attacks were independently validated. There were 433 strokes and 163 transient ischaemic attacks identified during follow-up. Of these, 333 were the first ever in a lifetime strokes of which 139 were definite ischaemic, 20 were haemorrhagic and 168 were probable ischaemic strokes. The crude incidence rate for stroke was 445 (95% confidence interval 398-493) per 100 000 person years. The age-standardised rates for 10 y age-bands were: 45-54 y 91 (10-172); 55-64 y 351 (269-432) and 65-74 y 855 (669-1040). The 30 d case-fatality rate was 21.0% (70/333) for all strokes and 19.2% (60/312) for ischaemic strokes. For transient ischaemic attacks the age-standardised incidence rates for the same 10 y age bands were 92 (4-179), 111 (64-157), and 273 (167-80), respectively. These rates for stroke transient ischaemic attack are likely to be accurate given the high ascertainment of events in this representative population of middle-aged men. Such studies, reporting reliable measures of cerebrovascular events, are important for measuring burden of disease, and for analysis of risk factor associations to help improve understanding of stroke aetiology and inform preventive efforts.

The incidence and aetiology of stroke in the Caerphilly and Speedwell Collaborative Studies II: risk factors for ischaemic stroke

Reduction of stroke burden requires preventive interventions targeted at important risk factors. This report presents the analysis of risk factors for ischaemic stroke from a representative cohort of middle aged men from South Wales and south-west England. Data on risk factors were collected through validated questionnaires and physical and clinical measurements. Details of possible cerebrovascular events were retrieved, classified into ischaemic, haemorrhagic and uncertain subtypes, and validated. The ratio of definite ischaemic to definite haemorrhagic strokes was calculated. This showed that the vast majority of strokes of unknown subtype were likely to ischaemic. After exclusion of known haemorrhagic strokes and subarrachnoid haemorrhages the remaining strokes were labelled ischaemic. Hazard ratios for possible risk factors were calculated for all ischaemic, and for fatal and non-fatal strokes. There were 293 ischaemic strokes. Statistically significant age-adjusted hazard ratios were: 1.50 (95% confidence interval 1.16-1.95) for being in a manual social class, 1.82 (1.24-2.67) if smoking >15 cigarettes/d at enrollment, 1.19 (1.13-1.24) and 1.23 (1.14-1.34) per 10 mmHg increase in systolic and diastolic blood pressure, respectively, 0.67 (0.46-0.96) for the top quintile high density lipoprotein-cholesterol:cholesterol ratio compared to the bottom quintile, 2.04 (1.40-2.99) for presence of angina, 3.90 (2.01-7.58) for presence of atrial fibrillation, and 3.35 (1.90-5.80) for presence of diabetes. Risk factors were more strongly associated with fatal than non-fatal strokes. Multivariate analyses revealed that, while there was some attenuation of the effect of social class, angina and elevated BP, the risks from atrial fibrillation and diabetes were increased.

Height and cancer mortality: results from the Glasgow University student cohort

The aim of the study was to examine the association between height and cancer mortality in a socially homogeneous group of subjects. The study was based on a cohort of students, 8397 men and 2329 women, aged 16-30 y, who attended the University of Glasgow between 1948 and 1968. Mean follow-up time was 40 y. Height was measured at a medical examination performed at the student health service. The outcome measures used in the study were all-cause mortality and mortality from: all cancers, smoking and non-smoking related cancers and cancers related to sex hormones. No substantial or statistically significant associations were seen between height and all-cause or all-cancer mortality in either sex. Neither were any significant associations found between height and any of the sub-types of cancer studied (ie those related to smoking, those not related to smoking, and those related to sex hormones). Previous observations which have shown positive associations between height and cancer mortality have generally been based on populations with diverse social origins, among whom the variation in height will reflect variation in health and nutrition in childhood. The relatively low level of such variation in the present study may account for the negative findings. Public Health (2000) 114, 451-455

Inequalities in health: approaches by health authorities in an English health region

BACKGROUND

In 1995 the Department of Health published Variations in health: what can the Department of Health do? This recommended that health authorities should have a comprehensive plan for identifying and tackling variations in health. We investigated how health authorities in the South and West Region were taking forward this work.

METHODS

Semi-structured interviews and reviews of documentation were conducted in all health authorities in the South and West Region of England.

RESULTS

All health authorities viewed tackling inequalities in health as important; however, explicit strategies did not exist and Health of the Nation targets were a vehicle for determining priorities of inequalities. Explicit corporate commitment was often weak. Analyses were being conducted to determine the magnitude of local health inequalities and to assist in designing appropriate interventions. The importance of alliance working was highlighted; much work was being done although success was variable.

CONCLUSIONS

Efforts are being made throughout the South and West region to tackle inequalities in health. Although strategic vision at the corporate level was often lacking, there was evidence of commitment to taking the inequalities agenda forward within public health directorates. Strengthening of primary care and alliance working roles is essential. Recent national strategy documents, forthcoming legislation, and a review of health inequalities recognize the health effects of inequalities and require health authorities to collaborate with local partners to tackle these, and will offer opportunities to improve corporate commitment and alliance working. Uptake and success of these opportunities will have a major influence on progress in tackling health inequalities.

Blood pressure in young adulthood and mortality from cardiovascular disease

Blood pressure measured in young adult men is positively associated in later life with increased cardiovascular disease mortality. The implication of this finding is that risk of cardiovascular disease starts in early life.

Determinants of adolescent blood pressure: findings from the Glasgow University student cohort

OBJECTIVE

To establish whether the blood pressure (BP) of young adults is related to their physical or behavioural attributes.

DESIGN

Cross-sectional study.

SUBJECTS

A total of 11,284 males and 3491 females who attended the University of Glasgow between 1948 and 1968.

OUTCOME MEASURES

Systolic and diastolic BP.

RESULTS

Body mass index (BMI) and weight were positively associated with BP in males and females. Height had a small positive association with male systolic BP and female diastolic BP. Haemoglobin levels were associated with raised BP in females. Albuminuria was associated with raised BP in males but not females. Smoking and alcohol consumption were associated with small negative effects on BP, although the measurement of alcohol consumption in the study was crude, and these results may not be free of confounding. Insufficient outdoor exercise was associated with higher BP in females but not males. No social class gradients in BP levels were seen, although having a higher number of siblings was associated with slightly lower BP in males.

CONCLUSION

The results from the current study indicate that modifiable risk factors, such as weight and exercise affect the BP of young adults. The impact of these factors, coupled with the known tracking of BP from adolescence to adulthood, emphasise the importance of healthy behaviour patterns in young people.

Self reported health of people in an area contaminated by chromium waste: interview study

OBJECTIVES

To compare the self reported health of a group of individuals living in an area contaminated by chromium (chromium group) with a group living in an uncontaminated area (control group), and to assess the effects of perception of risk from exposure to chromium on health.

DESIGN

Cross sectional study using the SF-36 validated quality of life questionnaire. Further questions were added to examine the relations between perceptions about living on or near land contaminated with chromium and the effects on self reported health.

SETTING

An area contaminated with chromium (Cambuslang, Carmyle, and Rutherglen) and a control area (Barrmulloch and Pollok).

PARTICIPANTS

Residents of an area containing chromium landfill and residents of an uncontaminated control area.

MAIN OUTCOME MEASURES

Scores on SF-36.

RESULTS

Little difference was found in health scores between the two groups, and only for general health was there a significantly higher score in the chromium group. Health scores for the chromium group were significantly worse across all dimensions for those who believed that chromium adversely affected health. Most of the chromium group (68%) would prefer money to be spent on improving amenities rather than on chromium remediation.

CONCLUSIONS

Similar self reported health among residents of the chromium and control groups indicates that there is no evidence of harm to health from exposure to chromium in this setting. Noticeably lower scores in participants who believed chromium to be harmful to health point to the potential importance of perception and possible anxiety. Given the overall greater desire for better amenities rather than remedial action, policy makers and planners should discuss with residents how best to spend resources before instigating expensive cleaning up programmes.

Similarities in the epidemiology of neural tube defects and coronary heart disease: is homocysteine the missing link?

It is hypothesised that a single aetiological pathway could explain both the strong ecological association between the birth prevalence of neural tube defects (NTD) and coronary heart disease (CHD) mortality and the potential efficacy of dietary measures, especially increased folic acid intake, in their prevention. The epidemiological similarities between NTD and CHD are strong and consistent suggesting that the relation is real rather than artefactual. It is suggested that this epidemiological association reflects a shared aetiology arising from the role of disturbed homocysteine metabolism in the pathogenesis of both conditions. Current public health measures designed to increase the intake of periconceptional folic acid in women, reinforced by a broadening of this policy to target both sexes throughout life, will (if successful) result in a reduction in both the birth prevalence of NTD and the incidence of CHD, although not necessarily contemporaneously. If disordered homocysteine metabolism is the cause of both NTD and CHD, this has implications for future research and preventive strategies for these serious and often lethal diseases.

Life course exposure and later disease: a follow-up study based on medical examinations carried out in Glasgow University (1948-68)

Evidence for the relationship between exposures in fetal life, infancy, childhood and early adulthood, and risk of chronic disease in later middle-age continues to accumulate. Further understanding of the associations between exposures acting over the life course and current morbidity and mortality in middle-age and later must depend upon the follow-up of previously established cohorts. This paper describes the design of, and background to, a follow-up of individuals who participated in a survey of student health in the University of Glasgow between 1948 and 1968. 15 332 students, almost a quarter of whom were female, had detailed medical information collected from a doctor-administered questionnaire and physical examination. Participation was voluntary; approximately 50% of the student population took part and these students were rep-resentative of the entire student population. Data collected include: socio-demographic, behavioural, developmental, anthropometric, and clinical details, as well as details of medical history and family health and structure. Data are over 95% complete for most variables. Over 40% of students were examined on two or more occasions with 1026 students (6.8%) having four or more examinations. Over 90% of students were from social classes I-III. Eighty-two per cent (12 533/15 322) of the students have been traced and flagged through the National Health Service Central Register and attempts are on-going to increase this figure. Those study members who have been traced are representative of the original cohort. To date 1111 (7.2%) of those traced have died. These data constitute a unique record of the health and physical development of a large cohort of students from Glasgow. Follow-up to investigate the relationship between indices of health and development, (height, weight, blood pressure), health behaviours and social circumstances in childhood and young adulthood, and mortality and morbidity in later adulthood is under way.

Identification of alpha 1-acid glycoprotein (orosomucoid) in human synovial fluid by capillary electrophoresis

Capillary electrophoresis of human synovial fluid in a phosphate borate run buffer containing sodium dodecyl sulphate separates a hydrophilic glycoprotein, hyaluronan and a number of low-molecular-mass components. The hydrophilic glycoprotein is identified as alpha 1-acid glycoprotein (AGP), orosomucoid, by co-injection methods with human AGP and by reaction with neuraminidase which released N-acetylneuraminic acid. Finally, a sample of the glycoprotein was isolated by micropreparative capillary electrophoresis, examined by sodium dodecyl sulphate-polyacrylamide gel electrophoresis methods and shown to give a positive reaction with AGP antibodies. The peak due to AGP in the capillary electrophoresis is broad and gives evidence for the presence of glycoforms.