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Biomedical subjects

I J Perry

Publications and source records attributed to I J Perry.

At least 55 records · Page 3Linked to original sources
PubMed1996

Serum insulin and incident coronary heart disease in middle-aged British men.

Earlier studies have not resolved the question of whether elevated circulating insulin levels are independently related to the development of coronary heart disease. Previous studies have not used a specific insulin assay and in all but a minority of studies that have addressed this issue it has not been possible to adjust for possible confounding due to high density lipoprotein (HDL) cholesterol. The authors examined the relation between serum insulin concentration and major coronary disease events (fatal and non-fatal myocardial infarction) in the British Regional Heart Study. The data are based on 5,550 men (aged 40-59 years) in 18 towns whose baseline, non-fasting serum samples were analyzed for insulin using a specific enzyme-linked immunoadsorbent assay (ELISA) method. Known diabetics were excluded. At 11.5 years of follow-up, 521 major coronary disease events had occurred, 261 fatal and 260 non-fatal. A nonlinear relation between serum insulin and coronary disease events was observed with an almost twofold increased relative risk in the 10th decile of the serum insulin distribution (> or = 33.8 mU/liter) relative to the 1st to the 9th deciles combined (age-adjusted relative risk (RR) = 1.9, 95% confidence interval (CI) 1.6-2.4). There was some attenuation of this association on cumulative adjustment for a wide range of biologic and life-style coronary disease risk factors, including HDL cholesterol, though it remained significant in the fully adjusted proportional hazards model (RR = 1.6, 95% CI 1.1-2.3). Similar associations between insulin and coronary disease events were seen in men with and without evidence of coronary disease at screening and in men with baseline serum glucose below the 80th percentile. These data are consistent with the hypothesis that a high level of serum insulin (hyperinsulinemia) is atherogenic, with a threshold effect. However, the markedly nonlinear form of the association and the attenuation in multivariate analysis strongly suggest that elevated insulin levels may only be a marker for common etiologic factors in the development of both coronary disease and non-insulin-dependent diabetes mellitus.

Adult↗
PubMed1996

Prospective relations between Helicobacter pylori infection, coronary heart disease, and stroke in middle aged men.

OBJECTIVE: To determine whether Helicobacter pylori, a chronic bacterial infection often acquired in childhood, is associated with increased risk of coronary heart disease and stroke later in life. DESIGN: Nested case-control study. SETTING: Prospective study of cardiovascular disease in men aged 40-59 years at entry (1978-1980) in 24 British towns. SUBJECTS: 135 cases of myocardial infarction and 137 cases of stroke occurring before December 1991; 136 controls were identified, frequency matched to cases by town and age group. METHODS: Serum samples stored at entry were analysed by an enzyme linked immunosorbent assay for the presence of H pylori specific IgG antibodies. RESULTS: 95 of the myocardial infarction cases (70%) and 93 (68%) of the stroke cases were seropositive for H pylori compared with 78 (57%) of the controls (odds ratio for myocardial infarction 1.77, 95% confidence interval (CI) 1.06 to 2.95, P = 0.03; odds ratio for stroke 1.57, 95% CI 0.95 to 2.60, P = 0.07). Helicobacter pylori infection was associated with manual social class, residence in Northern England or Scotland, cigarette smoking, higher systolic pressure and blood glucose, and a lower height-standardised forced expiratory volume in one second. Adjustment for these factors attenuated the relation between H pylori and myocardial infarction (odds ratio = 1.31, 95% CI 0.70 to 2.43, P = 0.40) and effectively abolished the relation with stroke (odds ratio = 0.96, 0.46 to 2.02, P = 0.92). The relation between helicobacter infection and fatal myocardial infarction was slightly stronger (odds ratio 2.41, 95% CI 1.13 to 5.12) but was also markedly attenuated after adjustment (1.56, 95% CI 0.68 to 3.61). CONCLUSION: In this prospective study the association between Helicobacter pylori infection and increased risk of myocardial infarction and stroke was substantially confounded by the relation between this infection, adult social class, and major cardiovascular risk factors.

Adult↗
PubMed1996

Hematocrit and risk of NIDDM.

There is limited evidence that raised hematocrit levels may be associated with insulin resistance, which links cardiovascular disease with NIDDM. The association between hematocrit level at screening and the subsequent development of physician-diagnosed NIDDM during 12.8 years of follow-up was examined in a prospective study of 7,735 middle-aged men drawn at random from general practice in 24 British towns. With the exclusion of men with missing hematocrit data and men with diabetes at screening, data were available for 7,193 men, in whom there were 187 new cases of NIDDM during follow-up. The risk of NIDDM increased significantly with increasing hematocrit levels. There was more than a fourfold increase in relative risk (RR) of diabetes among men with a hematocrit of > or = 48% relative to those with a hematocrit <42%, adjusted for age and BMI (RR 4.5; 95% CI 2.5-6.3). On further adjustment for predictors of NIDDM with which hematocrit is correlated, there remained a strong linear association with the risk of diabetes. There was a nearly fourfold increased risk of NIDDM in the highest relative to the lowest hematocrit group in the fully adjusted proportional hazard model (RR 3.6; 95% CI 1.7-7.6). The strong positive association between hematocrit level and risk of diabetes was seen even after exclusion of men with preexisting ischemic heart disease. The findings suggest that a raised hematocrit level, which is a major determinant of whole blood viscosity, should be added to the cluster of risk factors that link NIDDM with atheromatous, vascular disease.

Adult↗
PubMed1995

Prospective study of serum total homocysteine concentration and risk of stroke in middle-aged British men.

Moderate hyperhomocysteinaemia is common in the general population and has been linked with cardiovascular disease. However, there are no data from prospective, population-based studies. We examined the association between serum total homocysteine (tHcy) concentration and stroke in a nested case-control study within the British Regional Heart Study cohort. Between 1978 and 1980 serum was saved from 5661 men, aged 40-59 years, randomly selected from the population of one general practice in each of 18 towns in the UK. During follow-up to December, 1991, there were 141 incident cases of stroke among men with no history of stroke at screening. Serum tHcy was measured in 107 cases and 118 control men (matched for age-group and town, without a history of stroke at screening, who did not develop a stroke or myocardial infarction during follow-up). tHcy concentrations were significantly higher in cases than controls (geometric mean 13.7 [95% CI 12.7-14.8] vs 11.9 [11.3-12.6] mumol/L; p = 0.004). There was a graded increase in the relative risk of stroke in the second, third, and fourth quarters of the tHcy distribution (odds ratios 1.3, 1.9, 2.8; trend p = 0.005) relative to the first. Adjustment for age-group, town, social class, body-mass index, hypertensive status, cigarette smoking, forced expiratory volume, packed-cell volume, alcohol intake, diabetes, high-density-lipoprotein cholesterol, and serum creatinine did not attenuate the association. These findings suggest that tHcy is a strong and independent risk factor for stroke.

Adult↗
PubMed1995

Prospective study of risk factors for development of non-insulin dependent diabetes in middle aged British men.

OBJECTIVE: To determine the risk factors for noninsulin dependent diabetes in a cohort representative of middle aged British men. DESIGN: Prospective study. SUBJECTS AND SETTINGS: 7735 men aged 40-59, drawn from one group practice in each of 24 towns in Britain. Known and probable cases of diabetes at screening (n = 158) were excluded. MAIN OUTCOME MEASURES: Non-insulin dependent diabetes (doctor diagnosed) over a mean follow up period of 12.8 years. RESULTS: There were 194 new cases of non-insulin dependent diabetes. Body mass index was the dominant risk factor for diabetes, with an age adjusted relative risk (upper fifth to lower fifth) of 11.6; 95% confidence interval 5.4 to 16.8. Men engaged in moderate levels of physical activity had a substantially reduced risk of diabetes, relative to the physically inactive men, after adjustment for age and body mass index (0.4; 0.2 to 0.7), an association which persisted in full multivariate analysis. A nonlinear relation between alcohol intake and diabetes was observed, with the lowest risk among moderate drinkers (16-42 units/week) relative to the baseline group of occasional drinkers (0.6; 0.4 to 1.0). Additional significant predictors of diabetes in multivariate analysis included serum triglyceride concentration, high density lipoprotein cholesterol concentration (inverse association), heart rate, uric acid concentration, and prevalent coronary heart disease. CONCLUSION: These findings emphasise the interrelations between risk factors for non-insulin dependent diabetes and coronary heart disease and the potential value of an integrated approach to the prevention of these conditions based on the prevention of obesity and the promotion of physical activity.

Adult↗
PubMed1995

Predictors of ratio of placental weight to fetal weight in multiethnic community.

OBJECTIVE: To determine whether placental ratio is influenced by maternal ethnic origin, obesity, hypertension, and haematological indices of iron deficiency anaemia. DESIGN: Observational study. SETTING: District general hospital in Birmingham. SUBJECTS: 692 healthy nulliparous pregnant women, of whom 367 were European, 213 Asian, 99 Afro-Caribbean, and 13 of other or undocumented ethnic origin. MAIN OUTCOME MEASURES: Placental ratio and maternal body mass index, blood pressure, and haematological indices. RESULTS: Though birth weight and placental weight were lower in Asian women than in other groups, mean placental ratio was similar in Asian (19.5% (SD 3.3%)), European (20.0% (4.0%)), and Afro-Caribbean women (20.4% (5.3%)). Gestational age at birth was the main predictor of placental ratio in the univariate analysis (r = -0.34, P < 0.001) and multivariate analysis. The only other significant predictor of placental ratio in multivariate analysis was maternal body mass index, which was positively associated with placental ratio (r = 0.1, P = 0.01). Mean (SD) placental ratio was not significantly higher in women who developed gestational hypertension (20.4% (4.5%)) and pre-eclampsia (23.3% (7.3%)) than in normal women (19.8% (3.8%)). No evidence of a relation between placental ratio and first antenatal visit haemoglobin concentration or mean cell volume was detected, and placental ratio was not associated with change in mean cell volume during pregnancy or with third trimester serum ferritin concentration. CONCLUSIONS: These data do not support the proposed association between poor maternal nutrition and increased placental ratio. The association between high placental ratio and adult hypertension may be confounded by genetic and environmental factors associated with maternal obesity (and possibly maternal hypertension).

Adult↗
PubMed1994

Environmental factors in the development of essential hypertension.

Hypertension is predominantly a disorder of populations in which the fundamental problem is the tendency for blood pressure to rise with age. This phenomenon, which varies markedly across populations, is determined largely by environmental factors. We argue that the most important factors in the development of hypertension at the population level are calorie excess (as manifest by obesity), high salt intake, low potassium intake, physical inactivity, heavy alcohol consumption and psychosocial stress. Potential interactions between these factors (and the genetic endowment) are emphasized. We consider data from studies of blood pressure in children and adolescents and from intervention studies. The hypothesis that essential hypertension is initiated in fetal life is reviewed briefly. It is clear that the current high risk approach to prevention should be supplemented by a population based approach. There is controversy however regarding the value of certain interventions, such as salt restriction, at the population level. Ultimately community intervention trials will be required to resolve these issues.

Alcohol Drinking↗
PubMed1994

Haematocrit, hypertension and risk of stroke.

OBJECTIVES: To assess the relationship between haematocrit and risk of stroke. DESIGN: Prospective study of a cohort of men followed up for 9.5 years. SETTING: General practices in 24 towns in England, Scotland and Wales (British Regional Heart Study). SUBJECTS: A total of 7735 men aged 40-59 years at screening, selected at random from one general practice in each of 24 towns. MAIN OUTCOME MEASURES: Fatal and non-fatal strokes. RESULTS: During a follow-up period of 9.5 years for all men there were 123 stroke events (33 fatal) in the 7346 men in whom the haematocrit level had been determined. In the cohort as a whole, risk of stroke was significantly raised at haematocrit levels > or = 51% (relative risk [RR] = 2.5; 95% confidence intervals [CI] 1.2-5.0) after adjustment for age, social class, smoking, body mass index, physical activity, presence of diabetes and pre-existing ischaemic heart disease. Further adjustment for systolic blood pressure did not attenuate this association (RR = 2.4; 95% CI 1.2-4.9). A raised haematocrit was associated with an increase of stroke only in men with hypertension (systolic blood pressure > or = 160 mmHg or diastolic blood pressure > or = 90 mmHg or on regular antihypertensive treatment). No increased risk of stroke was seen at the higher haematocrit level (> or = 51%) in normotensive men. At haematocrit levels below 51%, hypertension was associated with a three-fold increase in risk of stroke compared with normotension (RR = 3.4, 95% CI 2.3, 5.1). At haematocrit levels > or = 51%, hypertension was associated with a nine-fold increase in risk of stroke compared with normotension (RR = 9.3; 95% CI 4.2, 21.0). Exclusion of men receiving regular antihypertensive therapy did not alter the strong associations seen. CONCLUSION: The data suggest that an elevated haematocrit is an independent risk factor for stroke and that it interacts synergistically with elevated blood pressure.

Adult↗
PubMed1994

The definition of pre-eclampsia.

BACKGROUND: Redman and Jefferies have proposed a revised definition of pre-eclampsia which is based on absolute blood pressure levels and an increment from the baseline in the first half of pregnancy. There is no requirement for proteinuria. This definition should facilitate the distinction between nonproteinuric pre-eclampsia and other causes of nonproteinuric gestational hypertension, such as chronic essential hypertension. OBJECTIVES: 1. To determine whether the blood pressure criteria of Redman and Jefferies can select women with characteristics of pre-eclampsia from the group of women with gestational hypertension by the current criteria of the International Society for the Study of Hypertension in Pregnancy (ISSHP). 2. To determine the level of agreement between the classification system proposed by Redman and Jefferies and that of the ISSHP. DESIGN: A prospective study. SETTING: Obstetric unit, Dudley Road Hospital, Birmingham, UK. SUBJECTS: Six hundred and ninety-two healthy nulliparous women and 11 women with chronic hypertension antedating pregnancy. MAIN OUTCOME MEASURES: 1. Differences in maternal characteristics and obstetric outcome among women with gestational (nonproteinuric) hypertension by the ISSHP criteria, meeting (and failing to meet) the Redman and Jefferies' blood pressure criteria. 2. The proportion of women classified as normal, proteinuric pre-eclampsia, and chronic hypertension on the basis of both Redman and Jefferies' criteria and the current ISSHP criteria. RESULTS: There were 55 women with gestational hypertension alone by the ISSHP criteria, of whom 33 met Redman and Jefferies' blood pressure criteria for pre-eclampsia. This group of 33 women had characteristics of nonproteinuric pre-eclampsia, compared with the remaining 22 women in the ISSHP gestational hypertension category who had characteristics of chronic hypertension. The group of 33 were significantly younger and less obese, had significantly lower blood pressure at their first antenatal visit and their obstetric outcome was poorer. The Redman and Jefferies' blood pressure criteria identified as normal 99.5% (95% CI, 98.6% to 99.9%) of women who were also characterised as normal on the basis of the ISSHP criteria (622/625). There were 12 women with proteinuric pre-eclampsia by the ISSHP criteria of whom 11 (92%; 95% CI, 62% to 99.8%) met Redman and Jefferies' blood pressure criteria for pre-eclampsia. None of the 11 women with chronic hypertension antedating pregnancy met these criteria. CONCLUSIONS: In this population the blood pressure criteria for pre-eclampsia proposed by Redman and Jefferies select women with features of pre-eclampsia (i.e., proteinuria and relatively poor outcome) and, in particular, they enable a distinction to be made between nonproteinuric pre-eclampsia and other causes of gestational hypertension.

Adult↗
PubMed1994

Asymptomatic hyperglycaemia and major ischaemic heart disease events in Britain.

OBJECTIVE: To examine the association between non-fasting serum glucose concentrations and major ischaemic heart disease (IHD) events (fatal and non-fatal myocardial infarction). DESIGN: A prospective study. SUBJECTS: A population based sample of 7735 middle aged British men. Known diabetics, men with a glucose concentration > or = 11.1 mmol/l at screening, and hypertensive patients taking regular medication were excluded from the analysis. With exclusions (n = 509) and missing glucose values (n = 49), there were 7177 men available for analysis. MAIN OUTCOME MEASURES: Major IHD events (fatal and non-fatal myocardial infarction) during 9.5 years follow up on all men. RESULTS: There were 505 major IHD events, 222 fatal and 283 non-fatal, in the 7177 men studied. There was a non-linear relation between the glucose concentration and the risk (per 1000 men per year) of all major IHD events and fatal IHD events, with the excess risk in the upper quintile of the glucose distribution (> or = 6.1 mmol/l). The unadjusted relative risks (RR) in the upper glucose concentration quintile compared with the first to the fourth quintiles combined were 1.4 (95% CI 1.1, 1.7) for all events and 1.3 (95% CI 1.0, 1.7) for fatal events. Adjustment for age, smoking, occupational status, body mass index, physical activity, systolic blood pressure, total and high density lipoprotein cholesterol, and triglyceride concentrations had a minimal effect on these relative risk estimates. This non-linear relationship between the serum glucose concentration and the risk of a major IHD event was observed in men with no evidence of IHD at screening (n = 5518) but not in men with IHD (n = 1659). In the former group, the RR (adjusted for major coronary risk factors) for all major IHD events in the upper quintile relative to the lower quintiles combined was 1.5 (95% CI 1.2, 2.0) and for fatal IHD events was 1.8 (95% CI 1.1, 2.6). CONCLUSION: These data suggest that asymptomatic hyperglycaemia is an independent risk factor for major IHD events.

Adult↗
PubMed1993

Ethnic differences in infant-rearing practices and their possible relationship to the incidence of sudden infant death syndrome (SIDS).

The aetiology of sudden infant death syndrome (SIDS) is still uncertain, although associations with overheating and the prone sleeping position have been reported. In the UK, the incidence of SIDS is considerably lower in infants of Asian origin, but as yet no explanation for this has been suggested. We have studied a group of 202 white and 172 Asian multiparous mothers attending an antenatal clinic to compare the sleeping position and home environment of infants in each ethnic group. We found that significantly more white infants (31%) than Asians (11%) were placed in the prone position at night and that 94% of Asian infants slept in their parents' bedroom, compared with 61% of whites. These observations demonstrate marked differences in the infant rearing practices favoured by Asians and whites and lend support to the concept that the prone position and separate bedrooms may be contributors to the development of sudden infant death.

Child Rearing↗
PubMed1993

Sporting activity and hyperglycemia in middle-aged men.

OBJECTIVE: To assess the relationship between self-reported frequency of participation in sporting activity and the prevalence of hyperglycemia (nonfasting glucose level > or = 7.8 mM) in middle-aged men. RESEARCH DESIGN AND METHODS: We used a cross-sectional study of 7617 British middle-aged men, drawn from 24 general practices in England, Wales, and Scotland, who were participants in the British Regional Heart Study. The response rate was 78%. Patients with diabetes (physician-diagnosed) were excluded from our analysis. Frequency of participation in sporting activity was determined by the respondents and reported as none (61%), occasionally (12%), or frequently (27%). RESULTS: The age-adjusted prevalence odds ratio for hyperglycemia was 0.86 (95% confidence interval, 0.6-1.2) in those reporting occasional, and 0.62 (95% confidence interval, 0.4-0.85) in those reporting frequent sporting activity, compared with those reporting none. This effect of frequent sporting activity on the prevalence of hyperglycemia was independent of body mass index, occupational status, smoking status, systolic blood pressure, use of antihypertensive therapy, and time of sampling. CONCLUSIONS: Frequent sporting activity in middle-aged men is associated with a reduced prevalence of hyperglycemia and may reduce the risk of NIDDM.

Adult↗
PubMed1992

Salt intake and stroke: a possible direct effect.

We have performed an ecological analysis of the relationship between regional mortality from cerebrovascular disease in western Europe and regional data on urinary sodium excretion, systolic blood pressure and relevant confounding variables. We have used published WHO cerebrovascular disease mortality rates and data provided by the INTERSALT study. Inter-relationships between these variables were investigated by linear regression analysis, with the regression coefficients, weighted for population size. On univariate analysis a significant linear relationship was observed between regional stroke mortality and median 24 hour urinary sodium excretion (coef. = 0.01, t = 3.28, P = 0.008), body mass index (coef. = 0.24, t = 3.21, P = 0.009) and alcohol intake (mls/week, coef. = 1.54, t = 3.99, P = 0.003). The relationship between stroke mortality and systolic blood pressure, though positive, was weaker than that between stroke mortality and sodium excretion and was not significant in this data. The stroke mortality sodium excretion relationship was independent of BMI on multivariate analysis. These data are consistent with the hypothesis that a high intake of salt may increase the risk of stroke, independent of effects on blood pressure.

Alcohol Drinking↗