Hans A. Valkenburg

Epidemiology of osteoarthritis: Zoetermeer survey. Comparison of radiological osteoarthritis in a Dutch population with that in 10 other populations.

The prevalence of mild and severe radiological osteoarthritis was investigated in a random sample of 6585 inhabitants of a Dutch village. Radiographs were graded 0-4 according to the criteria described by Kellgren and Lawrence. The prevalence of radiological osteoarthritis increased strongly with age and was highest for cervical spine (peak: men 84.8%, women 84.3%), lumbar spine (peak: 71.9%, women 67.3%), and distal interphalangeal joints of the hands (peak: men 64.4%, women 76%). Prevalence did not exceed 10% in sacroiliac joints, lateral carpometacarpal joints, and tarsometatarsal joints. Severe radiological osteoarthritis (grade 3 or grade 4) was uncommon under age 45; in elderly persons the prevalence of severe radiological osteoarthritis did not exceed 20% except for the cervical and lumbar spine, distal interphalangeal joints of the hands and, in women only, metacarpophalangeal joints, first carpometacarpal joints, first metatarsophalangeal joints, and knees. Overall, differences between men and women were small except for hips and knees; however, severe radiological osteoarthritis was found in a higher proportion in most of the joints in women. Our data were compared with data from similar population surveys. The slope between joint involvement and age was strikingly constant for most of the joints. Differences between populations were mainly differences in level. These differences of prevalence of radiological osteoarthritis may be attributed to interobserver differences--that is, different criteria used to establish radiological osteoarthritis, in addition to genetic or environmental factors, or both.

A 12 year follow up study in the general population on prognostic factors of cartilage loss in osteoarthritis of the knee.

The natural history and prognostic factors of cartilage loss in osteoarthritis of the knee were studied in subjects from a general population survey on rheumatic diseases in 1975-8. Baseline data were collected by questionnaire, physical examination, and weightbearing anteroposterior knee radiographs. Follow up of the subjects aged 46-68 years with radiological osteoarthritis grade 2-4 (Kellgren) took place in 1988-9. Cartilage loss was assessed by two observers who scored the change in joint space width between two radiographs. Thirty four per cent had cartilage loss. Prognostic factors and adjusted odds ratios (ORs) (95% confidence intervals) were: body mass index OR = 11.1 (3.3 to 37.3) fourth v first quartile; body weight OR = 7.9 (2.6 to 24.0) third v first tertile; age OR = 3.8 (1.1 to 13.4) > 60 v < or = 49 years; Heberdens nodes OR = 6.0 (1.5 to 23.1); clinical diagnosis of generalised osteoarthritis OR = 3.3 (1.3 to 8.3); and previous bow legs or knock knees OR = 5.1 (1.1 to 23.1). The relation of age with cartilage loss was also confounded by the presence of Heberdens nodes or a diagnosis of generalised osteoarthritis. There was no statistically significant relation for gender, meniscectomy, injury, uric acid concentration, chondrocalcinosis, smoking, and occupation related factors, except possibly standing.

Long-term Effects of Neonatal Sodium Restriction on Blood Pressure

In 1980, a randomized trial was conducted among 476 Dutch newborn infants to study the effect of a low or normal sodium diet on blood pressure during the first 6 months of life. At the end of the trial, systolic blood pressure in the low sodium group (n = 231) was 2.1 mm Hg lower than in the control group (n = 245). To investigate whether contrasting levels of sodium intake in infancy are associated with blood pressure differences in adolescence, we measured blood pressure in 167 children from the original cohort (35%) after 15 years of follow-up. We assessed the differences in systolic and diastolic blood pressure levels between the diet groups using a multivariate regression model with adjustment for potential confounders. The adjusted systolic blood pressure at follow-up was 3.6 mm Hg lower (95% confidence interval, -6.6 to -0.5) and the diastolic pressure was 2.2 mm Hg lower (95% confidence interval, -4.5 to 0.2) in children who had been assigned to the low sodium group (n = 71) compared with the control group (n = 96). These findings suggest that sodium intake in infancy may be important in relation to blood pressure later in life.

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.

Associations of radiological osteoarthritis of the hip and knee with locomotor disability in the Rotterdam Study

OBJECTIVE To assess the contribution of radiological osteoarthritis of the hips and knees to disabilities in the activities of daily living related to lower limb function. METHODS During a home interview 1156 men and 1739 women, randomly chosen from the source population of all independently living residents aged 55 years and over living in a district of Rotterdam (the Rotterdam Study) were asked about locomotor disability by six questions of the Health Assessment Questionnaire (HAQ) and about pain in the hips and knees in the past month. Radiographs of hips and knees were scored according to the Kellgren grading system for osteoarthritis. RESULTS The prevalence of locomotor disability, defined as at least some difficulty with three or more out of six lower limb functions, was 20.2% for men and 31.9% for women; hip pain was present in 8.3% of the men and 16.6% of the women; knee pain in 12.6% of the men and 22.3% of the women. The prevalence of radiological osteoarthritis grade 2+ of the hip was 14.1% for men and 15.9% for women, and of the knee 16.3% and 29.1% respectively. The odds ratio (OR) (95% confidence intervals) of hip radiological osteoarthritis for locomotor disability adjusted for age and all other variables was for men: 1.4 (0.9, 2.1) and for women: 2.2 (1.6, 2.9). The ORs of knee radiological osteoarthritis adjusted for age and all other variables were 1.1 (0.9, 2.1) and 1.4 (1.1, 1.8) respectively. Severe radiological osteoarthritis (grade 3+) was stronger associated. The ORs of pain in the hips or knees and morning stiffness were much higher (between 2.7 and 5.5 for men and between 2.1 and 5.1 for women). CONCLUSIONS Radiological osteoarthritis of the hip and knee are only weak independent predictors of locomotor disability in women, and not at all independently associated with locomotor disability in men. Age, pain of the hips and knees, and morning stiffness seem to be the most important independent determinants of locomotor disability.

Heritabilities of radiologic osteoarthritis in peripheral joints and of disc degeneration of the spine

OBJECTIVE To estimate the genetic influence on the occurrence of radiologic osteoarthritis (ROA) in the knees, hips, and hands and disc degeneration of the spine in the general population. METHODS A random sample of 1,583 individuals was drawn to estimate the prevalence of ROA and disc degeneration in the general population. Of 118 probands with multiple affected joint sites who were derived from this sample, we were able to recruit 257 siblings. The variance of ROA and disc degeneration within sibling pairs was compared with the variance between sibling pairs. Heritability estimates for ROA in the knees, hips, and hands and for disc degeneration of the spine were calculated. OA was defined according to radiologic criteria, using the Kellgren/Lawrence grading system. RESULTS We observed that hand ROA and disc degeneration of the spine were statistically significantly more frequent in siblings than in the random sample, whereas the prevalence of knee and of hip ROA was similar and lower, respectively. Heritability estimates for hand ROA and disc degeneration were statistically significant, P = 0.56 (95% confidence interval [95% CI] 0.34-0.76) and P = 0.75 (95% CI 0.30-1.00), respectively. For knee and hip ROA, no evidence of a genetic effect in the general population was found. Finally, the heritability estimate for a score that summed the number of joints affected in the knees, hips, hands, and spine was 0.78 (95% CI 0.52-0.98). All heritability estimates were adjusted for age, sex, body mass index, and bone mineral density. CONCLUSION The present study shows that in the general population, there is a strong genetic effect for hand ROA and disc degeneration of the spine. The findings on the total number of joints affected at multiple sites suggest genetic susceptibility to generalized OA.

Cigarette smoking and the development and progression of aortic atherosclerosis. A 9-year population-based follow-up study in women.

BackgroundCigarette smoking has been recognized as an important risk factor for cardiovascular disease in men and women. Whether the increased risk results from an atherogenic effect of smoking is still debated. We examined the relation between cigarette smoking and atherosclerotic changes in the abdominal aorta. Methods and ResultsThe association between cigarette smoking and atherosclerotic changes in the abdominal aorta was examined in a population-based cohort of 758 women, initially aged 45 to 64 years. All women were examined radiographically for calcified deposits in the abdominal aorta, which have been shown to represent intimal atherosclerosis. After 9 years of follow-up, atherosclerotic changes, indicating development or progression of plaques, could be demonstrated in 37% of women. A direct association was found between atherosclerotic change and number of cigarettes smoked per day. Compared with women who had never smoked, the relative risks of those who smoked 1 to 9, 10 to 19, and 20 or more cigarettes per day were 1.4 (95% confidence interval, 1.0 to 2.0), 2.0 (1.6 to 2.5), and 2.3 (1.8 to 3.0), respectively, after adjustment for age and other cardiovascular risk factors. Associations of atherosclerotic change with inhaling habit and duration of smoking were borderline significant after number of cigarettes smoked per day was taken into account. Among former smokers, the risk decreased with increasing duration of stopping but a significant excess risk was still observed after 5 to 10 years since quitting (relative risk, 1.6; 95% confidence interval, 1.1 to 2.2). ConclusionsThese follow-up data support the evidence for an effect of cigarette smoking on atherosclerosis. The findings suggest that the rate of atherosclerotic change may be reduced by cessation of smoking, but a residual effect appears to be present for at least 10 years.

Do clinical findings associate with radiographic osteoarthritis of the knee

From a population survey of 2865 subjects, test characteristics of a number of clinical findings relating to knee osteoarthritis were calculated against the standard of radiographic diagnosis. The clinical findings included from the history were age, gender, current pain in the knee, swollen knee, pain in both hands, morning stiffness, osteoarthritis in any joint, pain or stiffness, or both, in knees or hips when rising from seated position, and pain in knees or hips while climbing stairs; and from the physical examination: Quetelets index, Heberdens nodes, bony enlargement, palpable effusion, soft tissue swelling, limitation of knee function, pain with knee flexion, bony tenderness and, finally, the latex fixation test. Of 18 clinical variables, all but Heberdens nodes, palpable knee effusion, pain in both hands, and latex fixation test showed a significant association after adjustment for age. Neither one single variable nor a combination could predict radiographic osteoarthritis of the knee with reasonable accuracy and thus be applicable in clinical practice. The x ray film, therefore, keeps its place in the diagnosis of knee osteoarthritis in general practice as well as in epidemiological research.

Determinants of locomotor disability in people aged 55 years and over: The Rotterdam study

Locomotor disability, as defined by difficulties in activities of daily living related to lower limb function, can be the consequence of diseases and impairments of the cardiovascular, pulmonary, nervous, sensory and musculoskeletal system. We estimated the associations between specific diseases and impairments and locomotor disability, and the proportion of disability attributable to each condition, controlling for age and comorbidity. The Rotterdam Study is a prospective follow-up study among people aged 55 years and over in the general population. Locomotor disability in 1219 men and 1856 women was assessed with the Stanford Health Assessment Questionnaire. Diseases and impairments were radiological osteoarthritis, pain of the hips and knees, morning stiffness, fractures, hypertension, vascular disease, ischemic heart disease, stroke, heart failure, chronic obstructive pulmonary disease (COPD), depression, Parkinsons disease, osteoporosis, diabetes mellitus, overweight, and low vision. Adjusted odds ratios, etiologic and attributable fractions were calculated for locomotor disability. The occurrence of locomotor disability can partly be ascribed to joint pain, COPD, morning stiffness, diabetes and heart failure in both men and women. In addition in women osteoarthritis, osteoporosis, low vision, fractures, stroke and Parkinsons disease are significant etiologic fractions. In men with morning stiffness, joint pain, heart failure, diabetes mellitus, and COPD a significant proportion of their disability is attributable to this impairment. In women this was the case for Parkinsons disease, morning stiffness, low vision, heart failure, joint pain, diabetes, radiological osteoarthritis, stroke, COPD, osteoporosis, and fractures of the lower limbs, in that order. We conclude that locomotor complaints, heart failure, COPD and diabetes mellitus contribute considerably to locomotor disability in non-institutionalized elderly people.

Epidemiology of rheumatic diseases in rural and urban populations in Indonesia: a World Health Organisation International League Against Rheumatism COPCORD study, stage I, phase 2.

To determine the incidence of musculoskeletal pain, disabilities, and help seeking behaviour, a questionnaire was administered to a rural population of 2184 men and 2499 women and an urban population of 481 men and 590 women aged over 15 years by house to house interviews with completion rates of 95.2% (rural) and 97.1% (urban). The incidences of pain in the joints, back, or neck were 23.6% (rural) and 31.3% (urban). The incidence of disability due to an inability to walk, lift, carry, and dress was 2.8% (rural) and 0.9% (urban). The percentage of the population with pain who had to stop work owing to disability was 75% (rural) and 78% (urban). Official health care facilities were used by 62% (rural) and 71% (urban) of the population. Traditional health care was used by 87% (rural) and 89% (urban). The high percentage of subjects unable to work was due to a predominance of manual labour occupations (rural, 90%, urban, 80%). The age and sex specific incidence of rheumatic diseases in these populations were similar to other developing and developed countries. The primary rheumatology service was inadequate due to the low priority given by the health service to non-communicable diseases and inadequate rheumatology teaching of the primary health care doctors during undergraduate training. Musculoskeletal pain is a major public health problem in Indonesia and is still not fully appreciated.