Biomedical subjects

A Hofman

Publications and source records attributed to A Hofman.

At least 343 records · Page 19Linked to original sources

PubMed1994

Reliability of intraocular pressure measurement with the Goldmann applanation tonometer in epidemiological studies.

The reproducibility of intraocular pressure (IOP) measurement with the Goldmann applanation tonometer was investigated as part of a population-based epidemiological study. Sixty-two subjects were examined in a first measurement session. The IOP was measured three times consecutively in both eyes according to a fixed protocol. The mean standard deviation (SD) of these measurements was 0.8 mmHg. The mean intraobserver variation for the first measurement was 1.64 (SD 2.07) mmHg. For the median of the three measurements the intra-observer variation was 1.50 (SD 1.96) mmHg. The mean inter-observer values were 1.79 (SD 2.41) mmHg for the first measurement and 1.60 (SD 2.15) mmHg for the median measurement. The correlation coefficient between the median values of the three measurements of both observers was 0.81. No systematic differences were found between the two observers. Using the median value of three consecutive measurements reduced the inter-observer variation by 11% and the intra-observer variation by 9% compared with a single measurement.

Aged↗

PubMed1994

Assessment of cerebral perfusion with single-photon emission tomography in normal subjects and in patients with Alzheimer's disease: effects of region of interest selection.

The shape, size and location of regions of interest (ROIs) show considerable variability between single-photon emission tomography (SPET) studies in aging and Alzheimer's disease, but the possible influence on study results remains unknown. We compared three different ROIs in a SPET study with 60 controls and in 48 patients with probable Alzheimer's disease diagnosed according to the NINCDS-ADRDA criteria. Regional cerebral blood flow (rCBF) was assessed with SPET using technetium-99m d,l-hexamethylpropylene amine oxime (99mTc-HMPAO), normalized to the mean activity in a cerebellar reference slice. The three different ROIs were: a multi-slice and a single-slice ROI with reference to the normal brain anatomy (using an anatomical atlas), and a rectangular (2 x 4 pixels) ROI in the frontal, temporal, temporoparietal and occipital cortices. No differences were observed for the means of rCBF values between the single-slice and multi-slice ROI's with reference to the normal anatomy, but some variability was present for individual comparisons. In contrast, significantly higher mean rCBF values were obtained with the single-slice rectangular ROIs in all four regions for both patients and controls and considerable variability was shown for individual subjects. After analysis with multivariate logistic regression and receiver operator characteristic curves, the ability of SPET to discriminate between controls and Alzheimer patients was similar in the three methods for mild and moderate Alzheimer patients (Global Deterioration Scale = GDS of 3 and 4). However, with increasing dementia severity (GDS > 4) the rectangular ROIs showed lower ability to discriminate between groups compared to the single-slice and multi-slice anatomically defined ROIs.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1994

Value of antibodies to GAD65 combined with islet cell cytoplasmic antibodies for predicting IDDM in a childhood population.

The value of a test for islet cell cytoplasmic antibodies together with a test for GAD65 antibodies to predict the subsequent development of diabetes over a period of 11.5 years was assessed in an open childhood population comprising 2,805 individuals. A single serum sample was obtained from each individual between 1975 and 1977 and screened for islet cell cytoplasmic antibodies for which eight individuals were positive (0.29%). During the average follow-up period of 11.5 years, four of eight islet cell antibody positive and three islet cell antibody negative individuals developed clinical diabetes. Sera from all individuals, who were islet cell antibody positive and/or developed diabetes (total of 11) and from 100 randomly selected control subjects were analysed for GAD65 antibodies. Six of eight islet cell antibody positive individuals were GAD65 antibody positive including all four who subsequently developed IDDM. Furthermore, one of the three islet cell antibody negative individuals who developed IDDM was GAD65 antibody positive both in 1976 and in 1989. Thus, a positive test for GAD65 antibodies alone correctly predicted diabetes in five of seven children, who developed the disease. Only one of the children, who developed diabetes was positive for insulin autoantibodies and this individual was also positive for islet cell cytoplasmic antibodies and GAD65 antibodies. One of the 100 control subjects was positive for GAD65 antibodies (1%). The results suggest that a single GAD65 antibody test may have a higher sensitivity for predicting IDDM than a test for islet cell cytoplasmic antibodies, but that a combined positive test for both antibodies increases the specificity for predicting IDDM over a period of 11.5 years.

Adolescent↗

PubMed1994

Alcohol and mortality. Results from the EPOZ (Epidemiologic Study of Cardiovascular Risk Indicators) follow-up study.

To investigate the association of alcohol intake with mortality from all causes, cardiovascular disease (CVD), cancer and other causes (e.g., accidents, violence, suicide), we performed an analysis of data obtained in a prospective follow-up study conducted in the Netherlands since 1977. Causes of death were defined for a cohort of 1,620 persons (760 men and 860 women) examined in 1977. During the 10-year follow-up period, 123 (7.6%) of the participants died. Frequency of alcohol consumption was obtained separately for wine, beer and liquor by means of a questionnaire. Although no significant association could be established between alcohol consumption and all-cause mortality, all-cause mortality tended to be lower in alcohol consumers compared to abstainers. The age- and sex-adjusted risk estimates of death from CVD were 0.29 (0.11-0.74), 0.46 (0.21-0.96) and 0.32 (0.13-0.77) for subjects with occasional, frequent and daily alcohol use, respectively, compared with those who did not drink at baseline. The mortality risks of never-drinkers and ex-drinkers were similar. A J- or U-shaped relation between alcohol consumption and CVD mortality could not be confirmed in our data but the available information on the amount of alcohol consumed was limited. No significant influence on the risk estimates of death from cancer or other causes was found. However, mortality tended to be higher for those who consumed more alcohol. The protective effect of alcohol intake on CVD mortality found in our data persisted after excluding subjects with cardiovascular or other major diseases at baseline from the analysis.

Adult↗

PubMed1994

Reproducibility of carotid vessel wall thickness measurements. The Rotterdam Study.

We studied the reproducibility of measurement of ultrasonographically assessed common carotid intima-media thickness and assessed whether measurement error of intima-media thickness occurred randomly or was associated with potential determinants of atherosclerosis. Eighty participants of the Rotterdam Study underwent a second ultrasound scan of both carotid arteries within 3 months of the first scan. The replicate measurements involved the posterior intima-media thickness of the distal common carotid artery. Mean differences (SD) in intima-media thickness of the right common carotid artery between paired measurements of sonographers, readers and visits were -0.004 mm (0.10), 0.066 mm (0.07), and -0.013 mm (0.13), respectively. Similar results were obtained for the left common carotid artery. Measurement error of intima-media thickness, i.e. the absolute difference in measurements between two subsequent visits, increased significantly with increasing common carotid intima-media thickness. This association disappeared after logarithmical transformation of the intima-media thickness data. Age, sex, smoking, body mass index, serum lipids, fibrinogen, and systolic and diastolic blood pressure were not significantly associated with the measurement error of intima-media thickness. Our findings indicate that measurements of common carotid intima-media thickness are highly reproducible. Measurement error of intima-media thickness is small and appears to be proportional with the level of intima-media thickness and is not significantly associated with most risk factors for atherosclerotic vessel wall disease.

Aged↗

PubMed1994

The prevalence of primary open-angle glaucoma in a population-based study in The Netherlands. The Rotterdam Study.

PURPOSE: The objective of this study is to assess the prevalence of primary open-angle glaucoma (POAG) in a defined population in Rotterdam, The Netherlands. METHODS: The Rotterdam Study is a single-center prospective cohort study of a total population of more than 10,000 people, 55 years of age or older. For the current analysis, the first 3062 consecutive, unselected, noninstitutionalized participants were examined according to standard protocols, including perimetry. The diagnosis of POAG was based on the presence of a glaucomatous visual field defect combined with either a vertical cup: disc ratio of 0.5 or more or a cup:disc ratio asymmetry of 0.2 or more, or an intraocular pressure (IOP) more than 21 mmHg, with open and normal anterior chamber angles. RESULTS: The overall prevalence of POAG in the current study was 1.10% (95% confidence interval [CI]: 1.09, 1.11). Age-specific prevalence figures increased from 0.2% (95% CI: 0.16, 0.24) in the age group of 55 to 59 years to 3.3% (95% CI: 2.57, 4.04) in the age group of 85 to 89 years. Men had a more than three times higher risk of having POAG than women (odds ratio, 3.6). In 52.9% of the patients, POAG had not been diagnosed previously. Of these patients, 38.9% had IOPs of 21 mmHg or lower. In 8.8% of the eyes (2.9% of patients), visual acuity was 20/200 or less due to POAG. CONCLUSION: The overall prevalence of POAG in the current study was 1.1%. The prevalence of POAG was higher in men than in women. Of the untreated patients, 38.9% had IOPs of 21 mmHg or lower.

Age Factors↗

PubMed1994

The association between age and bone mineral density in men and women aged 55 years and over: the Rotterdam Study.

In this cross-sectional study, bone mineral density (BMD) measurements were performed in 1762 ambulatory subjects (678 men and 1084 women) aged 55 years and over from the Rotterdam Study, a population based study of diseases in the elderly. BMD measurements of the proximal femur and lumbar spine were performed using dual energy X-ray absorptiometry. No age-related decline in BMD could be observed in the lumbar spine. Yearly percentage BMD reduction in women and men was -0.6% and -0.3% in the femoral neck, -0.8% and -0.5% in the Ward's triangle, and -0.4% and -0.3% in the trochanter, respectively. Late menopause was associated with high BMD in Ward's triangle and lumbar spine. We conclude that: (1) accurate assessment of age-related bone reduction in the spine is impossible from cross-sectional studies since BMD measurements in the elderly may be influenced by spinal osteoarthritis; and (2) the rate of age-related bone reduction in the femoral neck appears to be approximately two times higher in women than in men.

Absorptiometry, Photon↗

PubMed1994

Apolipoprotein E4 allele in a population-based study of early-onset Alzheimer's disease.

Several studies have reported an association of the apolipoprotein E allele epsilon 4 (APOE*4) to familial and sporadic late-onset Alzheimer's disease (LOAD). Here we report on the relationship between APOE*4 and early-onset Alzheimer's disease (EOAD) in a Dutch population-based study. The frequency of the APOE*4 allele was 2.3 times higher among EOAD cases compared to controls. Among patients, the allele frequency was 1.6 times higher in those with a positive family history than in those without. A significant increase in risk of EOAD was found for subjects homozygous for APOE*4 regardless of family history of dementia, but an increase in EOAD risk for APOE*4 heterozygotes could only be shown in subjects with a positive family history. Our study demonstrates a significant association between APOE*4 and EOAD which is modified by family history of dementia.

Adult↗

PubMed1994

Reduction of blood pressure with oral magnesium supplementation in women with mild to moderate hypertension.

In a double-blind controlled trial, 91 middle-aged and elderly women with mild to moderate hypertension who were not on antihypertensive medication were randomly assigned to treatment with magnesium aspartate-HCl (20 mmol Mg/d) or placebo for 6 mo. Magnesium aspartate-HCl in the given dose was well-tolerated and was not associated with an increased frequency of diarrhea compared with placebo. At the end of the study, systolic blood pressure had fallen by 2.7 mm Hg (95% CI -1.2, 6.7; P = 0.18) and diastolic blood pressure by 3.4 mm Hg (1.3, 5.6; P = 0.003) more in the magnesium group than in the placebo group. Blood pressure response was not associated with baseline magnesium status, as measured by dietary magnesium intake and urinary magnesium excretion. Urinary magnesium excretion in the magnesium group increased by 50% during the intervention period. No changes were seen in other biochemical indexes, including serum concentrations of total and high-density-lipoprotein cholesterol. The findings suggest that oral supplementation with magnesium aspartate-HCl may lower blood pressure in subjects with mild to moderate hypertension.

Administration, Oral↗

PubMed1994

Anthropometric measures, fitness and habitual physical activity in offspring of hypertensive parents. Dutch Hypertension and Offspring Study.

As part of the Dutch Hypertension and Offspring Study, subjects with contrasting risk for hypertension according to their parental history of hypertension were compared with respect to anthropometric measures and measures of fitness and physical activity. Body height, weight, two skinfolds, and blood pressure at rest were measured. Fitness was evaluated by a maximal exercise test, and habitual physical activity was assessed using a questionnaire. No differences were observed in body mass index after adjustment for slight differences in age and proportion of men between the groups (difference between groups: 0.74 kg/m2, 95% CI: -0.30, 1.78). Offspring of hypertensive parents, however, had significantly more central fat (difference between groups: 2.32 mm, 95% CI: 0.18, 4.46). No differences in fitness or physical activity were present between the two groups. The results of this study indicate a potential role for central fat in the etiology of primary hypertension. Fitness or habitual physical activity are, however, not different between groups of subjects at different risk for future hypertension.

Adolescent↗

PubMed1994

Physical activity and cardiovascular risk factors in rural Shanghai, China.

BACKGROUND: Data on the association between physical activity and cardiovascular risk factors among populations with a relatively high level of physical activity such as the Chinese, are sparse. METHODS: In 1991, as part of the Sino-Shanghai Cardiovascular Disease Registry Project, a cross-sectional survey was performed in a random sample of 1206 residents, aged 35-64 years, living in rural Shanghai, China. Information on physical activity was obtained by questionnaire. The level of physical activity was categorized into low, moderate and high, based on the presence of a weekly frequency (< 1, 1-2, > or = 3) of periods of 20 minutes that cause shortness of breath, increase in pulse rate and perspiration. Body mass index (BMI), systolic (SBP) and diastolic blood pressure (DBP) level, serum lipids levels, smoking status and heart rate were assessed. RESULTS: Across groups with low, moderate and high levels of physical activity, significant inverse trends were found for hypertension, total cholesterol, BMI and heart rate in men, and for hypertension, SBP and DBP, BMI and heart rate in women. High density lipoprotein cholesterol and current smoking were not related to physical activity. When differences in BMI were allowed for, the association between physical activity and hypertension and serum cholesterol in men, and with hypertension, SBP and DBP in women, were attenuated. CONCLUSIONS: Our findings from a population-based survey in China suggest that a high level of physical activity is associated with favourable levels of some of the established cardiovascular risk factors in men and women.

Adult↗

PubMed1994

Determinants of trunk abnormalities in adolescence.

BACKGROUND: The relationship between gender, anthropometric factors, adolescent growth, maturation and incidence of trunk abnormalities was studied in 2819 children who were symmetric at baseline examination. METHOD: At age 11 years and at age 13 years, data on height, weight, onset of adolescent growth spurt, pubertal phase and menarche were collected and examination for trunk abnormalities was performed. Data analysis included calculation of 2-year cumulative incidence and relative risks (RR) of trunk abnormalities. RESULTS: Two-year cumulative incidence was 11%. The RR for boys was 0.78 (95% confidence interval (CI): 0.63-0.96) compared to girls. Height was the strongest predictor for the development of trunk abnormalities in both sexes. The RR increased after adjustment for weight, onset of growth spurt, pubertal phase, and menarche. The RR was higher for girls with onset of adolescent growth spurt compared to girls who had not yet started their adolescent growth spurt (RR = 1.45, 95% CI: 1.08-1.95). For girls who had reached menarche, the RR was 0.48 (95% CI: 0.24-0.96) compared to those who had not reached menarche. CONCLUSIONS: Our findings suggest that taller 11 year old girls with onset of adolescent growth spurt have increased risk of future trunk abnormalities, but that having reached menarche has a protective effect.

Adolescent↗

PubMed1994

Common carotid intima-media thickness and lower extremity arterial atherosclerosis. The Rotterdam Study.

High-resolution B-mode ultrasonography of the carotid arteries is used to investigate the signs of early atherosclerotic vessel wall disease. To assess whether carotid artery findings reflect atherosclerosis elsewhere, we studied the association between common carotid intima-media thickness and lower extremity arterial atherosclerosis among the first 1000 participants of the Rotterdam Study. The Rotterdam Study is a single-center population-based prospective follow-up study of 7983 subjects, > or = 55 years old. Baseline measurements include ultrasound imaging of intima-media thickness of the distal common carotid artery and determination of the ankle-to-arm systolic blood pressure index. Lower extremity arterial disease was defined as an ankle-arm index < 0.90 in at least one leg. An increase of 0.1 mm in common carotid artery intima-media thickness was associated with an age- and sex-adjusted reduction of the ankle-arm index of 0.026 (95% confidence interval [CI]: 0.018 to 0.034). The age- and sex-adjusted odds ratio of lower extremity arterial disease for subjects with an intima-media thickness > or = 0.89 mm (upper quintile) to that of subjects with an intima-media thickness < 0.89 mm was 3.4 (95% CI: 2.2 to 5.2). Analysis among subjects free from symptomatic cardiovascular disease yielded a reduction in ankle-arm index per 0.1 mm increase in intima-media thickness of 0.018 (95% CI: 0.008 to 0.28) and an odds ratio for lower extremity arterial disease of 3.0 (95% CI: 1.7 to 5.1). Adjustments for differences in serum lipids, hypertension, and current smoking status only slightly attenuated the results.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1994

Cognitive correlates of ventricular enlargement and cerebral white matter lesions on magnetic resonance imaging. The Rotterdam Study.

BACKGROUND AND PURPOSE: Ventricular enlargement and white matter lesions are frequent findings on cerebral magnetic resonance imaging scans of elderly subjects. In demented subjects they seem related to the severity of the dementia, but in nondemented subjects their clinical significance is less clear. We investigated the relation of size of the lateral ventricles and white matter lesions with cognitive function in a population-based random sample of nondemented elderly persons. METHODS: The study population consisted of 90 subjects, aged 65 to 84 years, who were randomly selected from the cohort of the Rotterdam Study, and who were not demented. The presence of white matter lesions and the ventricle-to-brain ratio were assessed on magnetic resonance scans. Participants were tested with a neuropsychological battery that covered a broad range of cognitive functions. RESULTS: Ventricular enlargement and white matter lesions were both and independently associated with poorer performance on all tests. After adjustment for age and sex, ventricular enlargement was significantly associated with worse scores on tests assessing global cognitive function (Mini-Mental State Examination, P = .02; Groninger Intelligence Test, P = .01), memory (Word List Learning delayed recall, P = .03), and executive control functions (Stroop part II, P = .02; Trial Making Test B, P < .01); for white matter lesions the differences were significant for tests measuring executive control functions and mental speed (Trail Making Test A and B, P = .01 and P < .01, respectively; verbal fluency, P = .01), and memory (Word List Learning delayed recall, P = .04). CONCLUSIONS: This study suggests that white matter lesions are primarily related to impairment of subcorticofrontal functions, whereas enlargement of the lateral ventricles is associated with disturbances of cortical functions as well.

Age Factors↗

PubMed1994

Stroke incidence and mortality in rural and urban Shanghai from 1984 through 1991. Findings from a community-based registry.

BACKGROUND: Mortality from stroke has declined in many countries. This decline may result from a fall in incidence of stroke or a decrease in case fatality from stroke. The present study was conducted to investigate the temporal trends of incidence rate, mortality rate, and case fatality of stroke in an urban and rural Chinese population. METHODS: A community-based registry study was established in 1983 in defined rural and urban areas of Shanghai with a population aged 35 to 74 years of approximately 86,000 subjects, adhering to the methods and definitions of the World Health Organization MONICA protocol. All stroke events occurring in the population aged 35 to 74 years in these areas were registered by a special three-level case-registration system. RESULTS: From 1984 through 1991, 1391 stroke cases were identified. No significant change in the incidence rate of stroke was observed from 1984 through 1991 in men and women living in rural and urban areas. Age-standardized mortality rates (per 100,000 person years) of stroke declined significantly during this period, except for rural women. The annual changes and 95% confidence intervals of age-standardized mortality rates were: for rural men -4.6% (-5.4, -3.9), for rural women -0.6% (-1.6, 0.5), for urban men -2.5% (-3.5, -1.6), and for urban women -4.7% (-5.2, -4.2). A significant decrease in case fatality from stroke from 1984 through 1991 was found among men living in rural areas (from 62.4% to 46.0%) and among women living in urban areas (from 48.4% to 33.3%). Overall case fatality, however, showed a nonsignificant decline over time. CONCLUSIONS: We observed a decline in stroke mortality rate in a rural and urban Chinese population. No significant changes in stroke incidence were found in this study, whereas case fatality appeared to have decreased, in particular among men living in rural areas and women living in urban areas.

Adult↗

PubMed1994

The diagnostic value of SPECT with Tc 99m HMPAO in Alzheimer's disease: a population-based study.

We studied the diagnostic accuracy of single-photon emission computed tomography (SPECT) with technetium 99m-labeled hexamethylpropylene amine oxime (Tc 99m HMPAO) in 48 patients with probable Alzheimer's disease (AD) according to NINCDS-ADRDA criteria and in 60 controls recruited from a population-based study. With logistic regression, we identified decreased temporal regional cerebral blood flow as the best discriminating variable between patients and controls. Receiver-operator characteristic curves showed that the discriminative ability of SPECT improved with increasing dementia severity. With specificity set at 90%, sensitivity figures were 42% in mild, 56% in moderate, and 79% in severe AD. The diagnostic gain as a function of the prior probability of the disease being present was computed for those with mild AD. When the prior probability varied at around 50%, the diagnostic gain for mild AD patients was substantial (a maximum of 34%) for a positive test result but poor for a negative test result. The results suggest that the practical usefulness of SPECT as a diagnostic adjunct in patients suspected of having mild AD is confined to situations in which, on clinical grounds, there is considerable diagnostic doubt.

Aged↗

PubMed1994

[Local immunomodulation in atopic and nonatopic children with nonspecific respiratory tract diseases].

The authors report their own results of local immunomodulation with IRS 19 in 57 atopic and nonatopic children having nonspecific chronical diseases of the respiratory tract. The results were obtained on the basis of complex diagnostical procedures before and after local immunomodulation. These results are demonstrated by tables, figures and graphs. By comparing the results obtained with local immunomodulation, it was found that prophylactic and therapeutic efficiency of IRS 19 is better in nonatopic children than in atopic ones. The detailed analyses showed that the local immunomodulation caused not only an increased concentration of the immunoglobulins IgG, IgM, IgA but also of the IgE.

Adjuvants, Immunologic↗

PubMed1994

A population-based study of familial Alzheimer disease: linkage to chromosomes 14, 19, and 21.

Linkage of Alzheimer disease (AD) to DNA markers on chromosomes 14, 19, and 21 was studied in 10 families in which the disease was apparently inherited as an autosomal dominant trait. Families were derived from a Dutch population-based epidemiologic study of early-onset AD. Although in all probands the onset of AD was at or before age 65 years, the mean age at onset was after age 65 years in four families (referred to as "LOAD"). Among the six families with early-onset AD (referred to as "EOAD," i.e., mean age of onset of AD of relatives was at or before age 65 years), conclusive linkage to 14q24.3 was found in one family with a very early onset (around 47 years), while linkage to the same region was excluded in two other families. For the LOAD families, predominantly negative lod scores were obtained, and the overall lod score excluded linkage to chromosome 14. The results with markers on chromosome 19 and chromosome 21 were not conclusive for EOAD and LOAD. The findings of our study confirm genetic heterogeneity within familial EOAD.

Aged↗