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H A Valkenburg

Publications and source records attributed to H A Valkenburg.

At least 19 recordsLinked to original sources
PubMed1995

[Locomotor disability in the elderly; the ERGO Study (Erasmus Rotterdam Health and the Elderly). ERGO Study Group].

OBJECTIVE: Determination of the prevalence of locomotor disability and its association with signs and symptoms of the hips and knees in a Dutch general population aged 55 years and over. DESIGN: Cross-sectional population-based study. SETTING: Rotterdam-Ommoord, the Netherlands. METHOD: During home interviews of 1,901 men and 3,132 women aged 55 years and over living in the Ommoord district of Rotterdam, locomotor disability was assessed using the Health Assessment Questionnaire (HAQ). Morning stiffness and pain in the hips and knees during the past month were assessed. At the research centre weightbearing radiographs of the hips and knees were taken. Radiological osteoarthritis was defined as Kellgren score 2 or more. A complete physical examination of the hips and knees was performed. RESULTS: The prevalence of locomotor disability was 21.9% for independently living men and 36.0% for independently living women. In homes for the elderly these figures were 84.0% en 96.5%, respectively. There were significantly elevated age-adjusted odds ratios for locomotor disability for women, people in homes for the elderly, independently living men with only primary education, independently living participants with a below-median net annual income and widowed men in homes for the elderly. Taking the associations between the independent variables into account only morning stiffness, pain in the hips and knees and restricted flexion of the hips and knees were independently associated with locomotor disability in men. In women radiological osteoarthritis of the hips and knees, restricted endorotation of the hip, instability and valgus deformity of the knees were also associated with disability. CONCLUSION: The prevalence of locomotor disability in people aged 55 years and over in the general population was high and associated with female sex, low education, low income and living in a home for the elderly. Of the signs and symptoms of the hips and knees only pain in the hips and knees, morning stiffness and restricted flexion of the hip were independently associated with locomotor disability. Radiological osteoarthritis of the hip and knee did not contribute much to the explanation of locomotor disability.

Activities of Daily Living↗
PubMed1995

Association of locomotor complaints and disability in the Rotterdam study.

OBJECTIVE: To determine the association between joint complaints and locomotor disability. METHODS: During a home interview survey 1901 men and 3135 women aged 55 years and over (the Rotterdam Study) were asked about joint pain and morning stiffness in the past month, and locomotor disability was assessed by six questions from the Health Assessment Questionnaire (HAQ). RESULTS: The prevalence of locomotor disability was 24.5% for men and 40.5% for women. The prevalence of joint pain in men was 0.7% for pain in the hips, knees, and feet simultaneously, 3.7% for pain at two joint sites, 16.0% for pain at one joint site, and 20.4% for pain in the hips and/or knees and/or feet (any joint site); the corresponding estimates for women were 1.9%, 9.0%, 23.7%, and 34.5%, respectively. The prevalence of generalised morning stiffness was 4.9% for men and 10.4% for women. The age adjusted odds ratios for locomotor disability in men ranged from 2.4 of pain at one joint site to 8.8 of pain at all three joint sites; for women these odds ratios varied between 2.5 and 5.7, respectively. The age adjusted odds ratios of generalised morning stiffness were 8.0 for men and 7.3 for women. CONCLUSION: There is a strong and independent association between locomotor disability and age, joint pain, and generalised morning stiffness in people aged 55 years and over. The odds for locomotor disability increase onefold for every year increase in age, while the presence of generalised morning stiffness is of greater influence than the presence of joint pain.

Activities of Daily Living↗
PubMed1995

Classification criteria: methodological considerations and results from a 12 year following study in the general population.

In a 12 year followup study on knee osteoarthritis (OA) in the general population, several methodological aspects of the development and choice of classification criteria were studied. It cannot be assumed that the American College of Rheumatology (ACR) criteria sets developed in a clinical setting with comparable sensitivity and specificity will give comparable results in the general population. Moreover, validity needs to be studied in the general population to show whether there is consistency of research findings in the study of the prevalence and the relationship with putative risk factors. We found that the clinical criteria sets, with or without laboratory criteria in a traditional format, do not give results consistent with the other sets of ACR criteria. Kellgren and Lawrence's criteria were shown to predict the presence of future OA according to the other sets of ACR criteria.

Follow-Up Studies↗
PubMed1994

J-shaped relation between change in diastolic blood pressure and progression of aortic atherosclerosis.

The J-shaped relation between diastolic blood pressure and mortality from coronary heart disease continues to provoke controversy. We examined the association between diastolic blood pressure and progression of aortic atherosclerosis in a population-based cohort of 855 women, aged 45-64 years at baseline. The women were examined radiographically for calcified deposits in the abdominal aorta, which have been shown to reflect intimal atherosclerosis. After 9 years of follow-up, slight progression of atherosclerosis was noted in 19% of women and substantial progression in 16%. The age-adjusted relative risk of substantial atherosclerotic progression in women with a decrease in diastolic pressure of 10 mm Hg or more was 2.5 (95% CI 1.3-5.6), compared with the reference group of women who had a smaller decrease or no change. The excess risk in this group was confined to women whose increase in pulse pressure was above the median (3.9 [1.5-9.9] vs 1.1 [0.3-4.2] in women with an increase in pulse pressure below the median). The relative risks for women with rises in diastolic pressure of 1-9 mm Hg and 10 mm Hg or more were 2.2 (1.1-4.3) and 3.5 (1.6-8.0), respectively. These findings suggest that a decline in diastolic blood pressure indicates vessel wall stiffening associated with atherosclerotic progression. They support the hypothesis that in low-risk subjects progression of atherosclerosis may be accompanied by a decrease in diastolic blood pressure rather than the opposing idea that low diastolic blood pressure precipitates the occurrence of atherosclerotic events.

Age Factors↗
PubMed1994

Adverse reactions attributed to sumatriptan. A postmarketing study in general practice.

There are several reports on cardiac adverse reactions attributed to the antimigraine drug sumatriptan in the recent literature. In order to assess the frequency and the character of adverse reactions to sumatriptan, a postmarketing cohort study was performed one year after registration of the drug in The Netherlands. With assistance of 86% of the drug dispensing general practitioners in The Netherlands, 1727 patients who had received sumatriptan were traced in July, 1992. Via their general practitioners, a questionnaire about use of sumatriptan, adverse reactions and other medication was sent to the patients in December 1992. During the study period, seven patients were lost to follow-up. Of the 1720 remaining patients, 1202 (70%) responded to the questionnaire, of whom 1187 had actually used sumatriptan. The most frequently reported suspected adverse reactions were paraesthesiae (139 patients, 95% CI 9.9%-13.5%) and dizziness (96 patients, 95% CI 6.5%-9.7%). Chest pain after use of sumatriptan was reported by 94 patients (7.9%, 95% CI 6.4%-9.4%), and according to the close temporal relationship with the intake of sumatriptan and a positive rechallenge, a causal relationship was probable in most of those patients. The frequency of chest pain attributed to sumatriptan was higher in females (9.0% vs 4.6%; relative risk 1.9, 95% CI 1.1-3.4). Age and hypertension were not associated with chest pain attributed to sumatriptan. Dyspnoea attributed to sumatriptan was reported by 26 patients (2.2%), and was associated with obstructive lung disease (relative risk 5.4 95% CI 1.7-16.9).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
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

The incidence of hip fractures in independent and institutionalized elderly people.

The incidence density of hip fractures in the population of Amsterdam, aged 70 years and over, was studied according to the type of residence. In 1989, 655 patients were admitted to nine hospitals within Amsterdam for a hip fracture. Postal codes were used to classify the residence of the population and the hip fracture cases as independent, home for the elderly or nursing home. Stepwise logistic regression was used for data analysis. The risk of hip fracture increased with age and was 1.7 times higher for women than for men. In the age group 70-74 years the relative risk (RR) was 7.6 for those in homes for the elderly and 5.8 for those in nursing homes, when compared with the independent elderly. This RR was approximately 1 for those in homes for the elderly aged 85 years and over. However, in nursing homes the RR was still 2.8 in the age group 95+. We concluded that, despite protective measures against falls, the institutionalized elderly are at greater risk of hip fracture than the independent elderly of the same age and sex. This higher risk is especially apparent in the 'younger' age groups.

Age Factors↗
PubMed1994

Impaired glucose tolerance and diabetes mellitus in a rural population in south India.

In the present study the prevalence of impaired glucose tolerance and non-insulin dependent diabetes mellitus in a rural population in South India was assessed and its associations with body mass index and a family history of diabetes mellitus. Data were obtained from inhabitants of two villages located in the North Arcot District of Tamil Nadu. After an overnight fast, 467 randomly selected subjects, aged 40 years or over, were given 75 g glucose orally. After two hours the capillary glucose level was determined. The prevalence of impaired glucose tolerance (2 h value > or = 7.8 mmol/l and < 11.1 mmol/l) was 6.6% (31 subjects). Non-insulin dependent diabetes mellitus (2 h value > or = 11.1 mmol/l) was found in 23 subjects (4.9%). Of these, 53% were previously unknown. Age and sex adjusted mean body mass index was significantly higher among subjects with impaired glucose tolerance compared to subjects without glucose intolerance, with a mean difference of 1.4 kg/m2 (95% confidence interval (CI) 0.2, 2.6). A positive family history of diabetes was non-significantly higher in subjects with impaired glucose tolerance. Subjects with non-insulin-dependent diabetes mellitus had a higher mean body mass index compared to subjects with normal glucose levels with a mean difference of 1.9 kg/m2 (95% CI 0.5, 3.3). A positive family history of diabetes was more common among diabetics with a difference of 20% (95% CI 10, 30). Our findings suggest that in a considerable proportion (11.5%) of the rural South Indian population aged 40 years or over glucose intolerance is present.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Swimming pool chlorination: a health hazard?

A pilot study addressed potential effects of long-term exposure to chlorination products in swimming pools. The indicator compound chloroform was detectable in blood from competitive swimmers in an indoor pool (mean = 0.89 +/- 0.34 microgram/l; n = 10), but not in outdoor pool swimmers. No hepatotoxic effect was indicated by serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT) or gamma-glutamyl transpeptidase (gamma-GT) enzyme levels. beta-2-microglobulin, an indicator of renal damage, was significantly elevated in urine samples of the slightly, but significantly, younger indoor swimmers. The precise ratio between these 2 possible causes, age and chloroform exposure, as well as the mechanism of the former, remain to be elucidated.

Alanine Transaminase↗
PubMed1994

Patient and strain characteristics in relation to the outcome of meningococcal disease: a multivariate analysis.

To investigate the joint association of patient and strain characteristics with the outcome of meningococcal disease (MD), data were collected on 563 consecutive cases of MD reported between 1989 and 1990 in The Netherlands. The meningococcal isolates were characterized with regard to their surface characteristics. Sequelae occurred in 8.5% of the patients, and were only associated with the presence of bacteraemia. The case-fatality rate was 7.7%. Infants aged < or = 5 months and patients in the age-groups of 10-19 years and > or = 50 years had an increased risk for a fatal outcome compared with children from 6 months to 9 years old (Odds Ratios [ORs]: 5.1, 3.4 and 9.8, respectively). The OR for females versus males was 2.3. The ORs for patients with bacteraemia, or a combination of bacteraemia and meningitis, compared with meningitic patients, were 2.3 and 3.1. Meningococcal strain characteristics did not influence the case-fatality rate substantially. In conclusion, host factors were found to be determinants for a fatal outcome of MD in The Netherlands from 1989 to 1990.

Adolescent↗
PubMed1994

Phenotypic and genotypic changes in a new clone complex of Neisseria meningitidis causing disease in The Netherlands, 1958-1990.

To characterize the phenotypic and genotypic changes that occurred in a new clone lineage of Neisseria meningitidis (lineage III) in the Netherlands, the electrophoretic type (ET) was determined for 79 serogroup B isolates of serotype 4 or subtype P1.4 (or both) obtained between 1958 and 1990 from patients with systemic meningococcal disease. Thirty-five previously described isolates were also included. After its appearance in 1980, lineage III started homogeneously with regard to both genotype (ET-24) and phenotype (B:4:P1.4). After 1984, other clones appeared in the lineage, and the various clones acquired other serotypes (serotypes 14 and 15) and subtypes (P1.2, P1.7, and P1.12), indicating frequent exchange of genetic material between clones. These results indicate that basing a serogroup B vaccine on outer membrane components from a single strain is not a valid strategy for the prevention of meningococcal disease.

Cloning, Molecular↗
PubMed1994

Lipo-oligosaccharide immunotyping of Neisseria meningitidis by a whole-cell ELISA with monoclonal antibodies.

To assess the applicability of a whole-cell ELISA (WCE) with monoclonal antibodies (MAbs) for lipo-oligosaccharide (LOS) immunotyping of Neisseria meningitidis, 675 meningococcal isolates obtained in 1989 and 1990 in the Netherlands and 57 isolates collected in 1974, of which the immunotype had been determined previously by microprecipitation, were analysed. Despite the lack of specific MAbs for L2 and L4, an algorithm was developed for the assignment of immunotypes on the basis of the reaction patterns of the reference strains and these isolates to a combination of 14 MAbs. The immunotypes found by WCE were in accordance with those obtained by microprecipitation and the results from WCE were reproducible. The distribution of immunotypes among isolates of the various serogroups in the Netherlands in 1989-1990 is presented. Based on the reaction patterns of the isolates, two main categories of related immunotypes could be distinguished among isolates of serogroups B and C: L2/L4 and L3/L1/L8. Some isolates of the latter category were of one immunotype, but many isolates expressed one or two additional immunotypes, either strongly or weakly, indicating that the differences in this category are quantitative rather than qualitative. The results of this study have demonstrated that the WCE method for LOS immunotyping is easily applicable and provides better definition of test strains for in-vitro bactericidal assays and research into pathogenesis.

Algorithms↗
PubMed1993

[Secondary cases of meningococcal disease in The Netherlands, 1989-1990; a reappraisal of chemoprophylaxis].

OBJECTIVE: To assess the secondary attack rate (SAR) of meningococcal disease among the household contacts of primary patients and to describe the use of chemoprophylaxis in the Netherlands. DESIGN: Descriptive, nation-wide survey. METHODS: Information was collected of patients with meningococcal disease, reported between April 1st, 1989 and April 30th, 1990, and their household contacts. A household contact suffering from meningococcal disease between 24 hours and 1 month after hospital admission of the primary patient, was considered to be a secondary case. Chemoprophylaxis was considered appropriate if rifampicin or minocycline had been prescribed to all household contacts within a maximum of one day after admission of the primary patient. RESULTS: There were 5 secondary cases (SAR: 0.3%). Chemoprophylaxis was prescribed to 627 of 1130 household contacts (55%). Of those the prophylaxis was considered appropriate in 46%. 2 secondary cases were not given any prophylaxis, 2 received penicillin and 1 rifampicin. Of the primary patients, 6% were given prophylaxis during their hospital stay. All meningococci, isolated from pairs of secondary and primary patients, were rifampicin sensitive. CONCLUSIONS: The SAR of meningococcal disease in the Netherlands is similar to that in other countries. Although prescription of chemoprophylaxis is not recommended by the government, it is prescribed to 55% of the household contacts, and in almost half of these instances it was considered to be appropriate. Chemoprophylaxis is rarely prescribed to primary patients. Recommendations concerning chemoprophylaxis in the Netherlands are in need of reappraisal. Based on the results from this study and the literature, the prescription of chemoprophylaxis to all household contacts of a patient with meningococcal disease, and to the index patient, is recommended.

Adult↗
PubMed1993

Determinants of bone mineral density and risk factors for osteoporosis in healthy elderly women.

Bone mineral density (BMD) and risk factors for osteoporosis were assessed in 348 apparently healthy women over 70 years of age (mean 82.3 years). BMD was measured at both hips and the dominant distal radius. With stepwise multiple regression the best determinants of BMD, selected from anthropometric measurements, age, and years since menopause, were body weight and years since menopause (R2 between 0.07 and 0.20, p < 0.001). Risk and protective factors for osteoporosis were analyzed as indicator variables by multiple regression and corrected for confounding by age, years since menopause, and body weight. Significantly lower BMD at the hip was found in participants with impaired mobility (-5%) and users of loop diuretics (-5%). Use of thiazide(like) diuretics did not influence BMD significantly at any site. Users of oral corticosteroids had a significantly lower BMD at the hip and the distal radius (range -9.1 to -24.3%). Participants with a history of Colles' fracture (n = 56) had a significantly lower BMD at the other radius (-12.9%). The mean calcium intake from dairy products was high (mean 921 mg/day), only 11% having an intake below 500 mg. A relation of calcium intake with BMD could not be detected at any measurement site. We conclude that BMD cannot be adequately predicted in elderly women. Risk factors for low BMD in the elderly are low body weight, high number of years since menopause, impaired mobility, and use of loop diuretics and oral corticosteroids. Calcium intake was not a risk factor in this study, but the number of individuals on a low calcium intake was small.

Aged↗
PubMed1993

Cardiovascular risk and all-cause mortality; a 12 year follow-up study in The Netherlands.

To assess the contribution of cardiovascular risk indicators to all-cause mortality, we used data from a follow-up study conducted in the Netherlands since 1975. Of 6,057 participants aged 20 years or over at the start of the study, 9.5% died during the 9 to 12 year follow-up period. Risk indicators independently related to all-cause mortality were age and diabetes mellitus in both sexes; pulse rate, smoking habits, antihypertensive drug use and a history of myocardial infarction most clearly in men; and body mass index and systolic blood pressure in women. A larger body mass index was associated with a gradual decrease in mortality probability. The risk of death for women in the highest quartile of body mass index (> 26.4 kg/m2) relative to those in the lowest quartile (< 21.9 kg/m2) was 0.56 (95% confidence limits 0.36 and 0.87). Serum cholesterol level showed no association with overall mortality. Risk functions were calculated to predict an individual's probability of dying within 11.5 years as a function of the level of cardiovascular risk indicators. Our findings suggest that the major cardiovascular risk indicators, apart from affecting cardiovascular morbidity and mortality, also influence all-cause mortality. Consequently, favourable changes in these characteristics might lead to an increase in life expectancy. The maximum individual benefit to be expected from these changes may be estimated using the risk functions derived from our data.

Adult↗