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Biomedical subjects

A Hofman

Publications and source records attributed to A Hofman.

At least 397 records · Page 22Linked to original sources

Aortic calcified plaques and cardiovascular disease (the Framingham Study).

The relation between the presence of calcified plaques in the thoracic aorta, as detected on chest x-rays, and the development of cardiovascular disease is examined during 12 years of follow-up of the Framingham cohort (n = 5,209). The prevalence of aortic calcified plaques approximately doubled with each decade of age, with only a trivial male predominance. Its presence was associated with a twofold increase in risk of cardiovascular death in men and women younger than age 65, even after other risk factors were taken into account. Similar increases in risk were found for coronary artery disease, stroke and intermittent claudication among middle-aged women. In middle-aged men these risks were less marked. The predictive value of aortic calcified plaques generally diminished with age. Risk of sudden coronary death in men with calcified plaques in the thoracic aorta ranged from a sevenfold increase at age 35 to no excess risk at age 70 years. These results support the view that atherosclerosis is a generalized process. The finding of aortic calcified plaques in a relatively young subject on a routine chest x-ray should be regarded as a sign for potential development of clinically manifest atherosclerotic disease in the cardiac, cerebral and peripheral arterial circulation.

Adult↗

Sodium and potassium intake and blood pressure change in childhood.

OBJECTIVE: To assess the association between sodium and potassium intake and the rise in blood pressure in childhood. DESIGN: Longitudinal study of a cohort of children with annual measurements during an average follow up period of seven years. SETTING: Epidemiological survey of the population of a suburban town in western Netherlands. SUBJECTS: Cohort of 233 children aged 5-17 drawn at random from participants in the population survey. MAIN OUTCOME MEASURES: At least six annual timed overnight urine samples were obtained. The mean 24 hour sodium and potassium excretion during the follow up period was estimated for each participant and the sodium to potassium ratio calculated. Individual slopes of blood pressure over time were calculated by linear regression analysis. RESULTS: No significant association was observed between sodium excretion and the change in blood pressure over time. The mean systolic blood pressure slopes, however, were lower when potassium intake was higher (coefficient of linear regression -0.045 mm Hg/year/mmol; 95% confidence interval -0.069 to -0.020), and the change in systolic pressure was greater when the urinary sodium to potassium ratio was higher (0.356 mm Hg/year/unit; 95% confidence interval 0.069 to 0.642). In relation to potassium this was interpreted as a rise in blood pressure that was on average 1.0 mm Hg (95% confidence interval -1.65 to -0.35) lower in children in the upper part of the distribution of intake compared with those in the lower part. The mean yearly rise in systolic blood pressure for the group as a whole was 1.95 mm Hg. Urinary electrolyte excretion was not associated with diastolic blood pressure. CONCLUSION: Dietary potassium and the dietary sodium to potassium ratio are related to the rise in blood pressure in childhood and may be important in the early pathogenesis of primary hypertension.

Adolescent↗

Serum levels of interleukin-6 are not elevated in patients with Alzheimer's disease.

Serum levels of interleukin-6 (IL-6) were determined in 97 patients with clinically diagnosed Alzheimer's disease and 79 age- and sex-matched control subject. Median serum levels of IL-6 did not differ significantly between Alzheimer patients (8.6 U/ml) and controls (8.2 U/ml). Median levels of serum IL-6 were similar for sporadic and familial patients. The concentration of IL-6 was not associated with the severity of the dementia or the duration of the disease since first symptoms. According to these observations there is no evidence for a significant elevation in serum IL-6 in Alzheimer's disease.

Aged↗

Do oral contraceptives increase blood pressure and serum total cholesterol in young women?

The effects of the use of oral contraceptives on serum lipids and blood pressure were studied among young women who participated in a longitudinal survey of risk factors for coronary heart disease (CHD) in the Netherlands. Fifty-three participants, ages 14 to 24 years, initiated oral contraceptive use during follow-up to the primary study on CHD. They continued oral contraceptive use for at least 2 subsequent years. From 53 age-matched control subjects, who did not use oral contraceptives, data were obtained for the same follow-up period. Women using oral contraceptives showed a significantly greater rise in serum total cholesterol levels than did the reference subjects (14 mg/100 ml/2 year vs 4 mg/100 ml/2 year; 95% confidence interval of the difference was 0.1 to 19.6). The increase in systolic blood pressure (4.7 mm Hg/2 year vs 2.1 mm Hg/2 year; 95% confidence interval of the difference was -1.8 to 6.9) did not differ between the groups. These findings suggest that oral contraceptive use may be associated with an enhanced rise in total cholesterol during adolescence.

Adolescent↗

Iron status in the acute phase and six weeks after myocardial infarction.

In a case-control study of 84 myocardial infarction patients and 84 population controls we investigated the association between iron status parameters and myocardial infarction during the acute phase and after six weeks. Immediately after the infarction mean ferritin levels were significantly higher, whereas iron levels and iron saturation of transferrin were significantly lower in cases than in controls. Six weeks after the infarction, serum iron levels were still significantly lower in cases than in controls. Neither serum ferritin levels nor serum iron levels did show a clear association with the size of the ischemic tissue damage as estimated by creatine phosphokinase levels. Our results indicate that serum ferritin and iron levels are influenced by the traumatic effects of the myocardial infarction. Possibly, these transient changes are an acute effect, as seen in infections. An increased uptake of iron in the reticulo-endothelial system for synthesis of ferritin, may account for the lowered serum iron level and the iron saturation of transferrin.

Aged↗

Metacarpal bone loss in middle-aged women: "horse racing" in a 9-year population based follow-up study.

Differences in the rate of metacarpal bone loss were evaluated in a 9 year population based follow-up study among 799 women initially aged 45-64 years, using initial and follow-up radiographs of the hands. Metacarpal bone loss started around the age of 50 years and was present in more than 95% of the women. The average annual rate of loss was approximately 1% of the initial value. The prevalence of osteopenia increased from 5% for women aged 45-49 years, up to 68% for women aged 70-76. The rate of bone loss was not similar for each individual. Regression analyses of rate of change-in-RCA on initial level of RCA indicated the presence of a consistent subgroup of fast bone losers. However, osteopenia at follow-up was more accurately predicted from initial bone density than from differences in the rate of loss.

Bone Density↗

Selenium status and cardiovascular risk factors in healthy Dutch subjects.

To provide further insight into the possible role of selenium in cardiovascular disease, we examined the relationship between cardiovascular risk factors, some nutritional parameters, and short- and long-term selenium status. A total of 82 healthy Dutch volunteers, 59 men and 23 women, aged 40-75 years, were studied. Means and standard deviations of selenium parameters were: plasma selenium 106.4 +/- 23.7 micrograms/L, erythrocyte selenium 0.59 +/- 0.19 microgram/g Hb, toenail selenium 0.78 +/- 0.17 ppm, and erythrocyte glutathione peroxidase activity 28.0 +/- 8.1 U/g Hb. No association was found between selenium status and gender, age, serum total-, LDL-, and HDL-cholesterol, systolic and diastolic blood pressure, alcohol intake, and body mass index. A significantly lower plasma selenium level was observed among smokers compared to nonsmokers (101.0 micrograms/L, SE = 3.9 vs 112.0 micrograms/L, SE = 3.6, p = 0.04). A significant negative association was found between erythrocyte selenium and serum levels of vitamin A and ferritin. No relevant relationship was observed between selenium status and serum fatty acid composition, vitamin E, vitamin B6, and iron. Apart from an association between smoking and short-term selenium status, we found no indications that a possible effect of selenium on cardiovascular disease may operate through the known risk factors.

Aged↗

The association between change in cognitive function and longevity in Dutch elderly.

The association between rate of change in cognitive function and longevity was investigated with data from the Dutch Longitudinal Study Among the Elderly. A group of 211 Dutch persons aged 65-84 years at baseline (1955-1957) was reexamined twice during an 8-year follow-up period, after which mortality was ascertained through 1983. Cognitive function was assessed based on an adaptation of the Wechsler Memory Scale. Rate of change in cognitive function during the 8 years of follow-up was determined by regression on time for each individual. Cognitive function declined significantly over the 8-year period (mean yearly change, -0.28 units; 95% confidence interval -0.34 to -0.22). The rate of decline in cognitive function was strongly associated with subsequent survival time in the ages 70 years and over, with those with a large decline having a short survival time. No association could be demonstrated in the age group 65-69 years. Adjustment for potential confounders did not affect the magnitude of the association. These findings suggest that the rate of decline of cognitive function is an independent predictor of longevity in older persons.

Aged↗

Haemophilia protects against ischaemic heart disease: a study of risk factors.

We previously reported that mortality due to ischaemic heart disease was lower in haemophilia patients than in the general male population. To support the hypothesis that this could be attributed to a protective effect of the clotting defect in haemophilia and not to differences in cardiovascular risk factors, we performed a second study. We examined 95 haemophilia patients for the presence of major risk factors for ischaemic heart disease and compared their risk factor profile with the data of epidemiologic surveys of the general Dutch population. Haemophilia patients had on average higher blood pressures than the comparison population, were more often hypertensive and used antihypertensive drugs twice as often. The mean serum cholesterol level of the patients was markedly lower than in the comparison population (4.8 versus 5.6 mmol/l, 95% confidence interval of the difference: 0.5-1.1 mmol/l). The risk factors were weighted into one theoretical risk ratio for ischaemic heart disease by application of logistic regression coefficients. The theoretical risk ratio based on the risk factor profile was 0.78. This risk ratio can only explain a moderate reduction in the incidence of ischaemic heart disease, much smaller than the mortality ratio of 0.20 we reported previously. Therefore these data support the hypothesis of a direct protective effect of haemophilia on the development of ischaemic heart disease.

Adolescent↗

Is parental age related to the risk of Alzheimer's disease?

Advanced maternal and paternal age were investigated as putative risk factors for AD in 198 clinically diagnosed Alzheimer patients and in 198 randomly selected healthy controls. No significant differences in average age of fathers and of mothers at birth of the subject were observed. The risk of AD was not significantly different across categories of maternal and paternal age. The association with parental age was not different for sporadic and familial AD. These findings do not support the view of a maternal or paternal age effect on AD.

Alzheimer Disease↗

Ten-year follow-up study of islet-cell antibodies and childhood diabetes mellitus.

To find out whether subclinical autoimmunity precedes onset of nonfamilial insulin-dependent diabetes mellitus (IDDM), 4806 schoolchildren aged 5-19 years from a township in Holland were followed-up for at least ten years after blood was sampled for measurement of islet-cell antibodies (ICA). ICA positivity conferred a relative risk of IDDM of 533 (95% CI 145-1955). In the 10 years of follow-up 4 of the 8 ICA-positive subjects became insulin dependent, whereas the probability of being free of IDDM was 99.9% for those who were ICA-negative at the start of the study. The findings suggest that, although chronic autoimmunity involving the pancreatic beta-cells may precede non-familial IDDM by many years, a positive ICA test on a single occasion predicts the development of IDDM in only 4 out of 8 subjects over a period of 10 years.

Adolescent↗

Increased risk of atherosclerosis in women after the menopause.

An increase in the incidence of cardiovascular disease has generally been observed in postmenopausal women, but there have been few studies of the association between menopausal state and atherosclerosis. In this study 294 premenopausal and 319 postmenopausal women aged 45 to 55 were examined radiographically for calcified deposits in the abdominal aorta, which have been shown to represent intimal atherosclerosis. Aortic atherosclerosis was present in eight (3%) of the premenopausal women and in 38 (12%) of the postmenopausal women. After adjustments for age and other indicators of cardiovascular risk women with a natural menopause had a 3.4 times greater risk of atherosclerosis than premenopausal women (95% confidence interval 1.2 to 9.7; p less than 0.05); women who had had a bilateral oophorectomy had a 5.5 times greater risk (1.9 to 15.8; p less than 0.005). No excess risk of atherosclerosis was observed among women who had had a hysterectomy without removal of both ovaries. These results suggest that when oestrogen production stops, either naturally or after surgery, the risk of atherosclerosis is increased.

Age Factors↗

Low vitamin B6 status in patients with acute myocardial infarction.

The vitamin B6 status of 84 patients with acute myocardial infarction was compared with that of 84 control subjects. Pyridoxal and pyridoxal 5'-phosphate (PLP) in plasma and erythrocytes, as well as the basal and total potential activity of the PLP-dependent enzyme aspartate aminotransferase in erythrocytes, were measured for a comprehensive assessment of vitamin B6 status. The mean levels of all vitamin B6 indexes (except pyridoxal) were lower in the patients than in the control subjects. The differences were statistically significant, except for erythrocyte PLP and total potential enzyme activity. The adjusted relative odds of a myocardial infarction for subjects in the lowest quartile of plasma PLP was about 5 times higher when compared with those in the highest quartile (relative odds = 5.2, 95% confidence interval = 1.4 to 18.9). Similar findings were found with the other vitamin B6 indexes. No significant association between infarct size, as estimated by creatine kinase level, and the vitamin B6 indexes was observed.

Aspartate Aminotransferases↗

Decreased selenium levels in acute myocardial infarction.

To study the association between selenium status and the risk of myocardial infarction, we compared plasma, erythrocyte, and toenail selenium levels and the activity of erythrocyte glutathione peroxidase among 84 patients with acute myocardial infarction and 84 population controls. Mean concentrations of all selenium measurements were lower in cases than controls. The differences were statistically significant, except for the plasma selenium level. A positive trend in the risk of acute myocardial infarction from high to low toenail selenium levels was observed, which persisted after adjustment for other risk factors for myocardial infarction. In contrast, erythrocyte glutathione peroxidase activity was significantly higher in cases than controls (31.3 +/- 8.4 U/g of hemoglobin and 28.0 +/- 8.1 U/g of hemoglobin, respectively). Because the toenail selenium level reflects blood levels up to one year before sampling, these findings suggest that a low selenium status was present before the infarction and, thus, may be of etiologic relevance. The higher glutathione peroxidase activity in the cases may be interpreted as a defense against increased oxidant stress either preceding or following the acute event.

Aged↗

The association between physical fitness and cardiovascular disease risk factors in children in a five-year follow-up study.

The relation between physical fitness and cardiovascular disease (CVD) risk factors was studied in 633 children selected from all fourth grades in 37 elementary schools in New York. They were participating in the control group of an intervention study to reduce CVD risk factors in children. Blood pressure, total and high-density lipoprotein (HDL) cholesterol and physical fitness were measured at baseline and at four subsequent examinations during five years of follow-up. Systolic blood pressure (SBP) at baseline was highest in children with poor physical fitness. The five-year change in physical fitness was inversely associated with the change in SBP, ie, children with the strongest decline in physical fitness showed the largest rise in SBP. HDL cholesterol at baseline was lowest in boys with poor physical fitness. The five-year change in physical fitness was positively related to the change in HDL cholesterol levels in boys; ie, boys with the largest decline in physical fitness had the largest decrease in HDL cholesterol level. These observations indicate that unfavourable long-term changes in physical condition in childhood may be related to unfavourable changes in blood pressure and serum lipids.

Blood Pressure↗