A. A. Kalla

Osteoporosis in developing countries

Osteoporosis poses a huge challenge in developing countries due to demographic transition and aging of the population coupled with limited availability of resources. The exact disease burden is difficult to quantify because of the paucity of data. Ethnicity affects bone density as well as fracture risk. Population-specific normative data for bone density are lacking in large parts of the world. Vitamin D deficiency is common even in sunny countries. The WHO has developed an algorithm for estimation of 10-year fracture risk which may be used even in the absence of bone mineral density.

Rheumatoid arthritis in the developing world

The general impression is that rheumatoid arthritis (RA) has a lower prevalence and a milder course in developing countries. Epidemiological studies from different regions show that varying prevalence is possibly related to urbanization. The data suggest that where severe disability does occur, it presents a significant health challenge because of scarce medical and social resources. Disease-modifying anti-rheumatic drugs (DMARDs) remain the mainstay of therapy to alter the natural history of the disease. New therapies are unlikely to be of general benefit in the developing world because of financial constraints and increased risk of infections, particularly tuberculosis, associated with the use of tumour necrosis factor-alpha blockers. Instead, future research in poorer communities should be directed at assessing the burden of disease, the role of early aggressive therapy with DMARDs in combination with glucocorticoids for the majority of patients with RA, and finally, sourcing targeted biological therapies through clinical trials and grants for compassionate use in patients with refractory disease.

Clinical assessment of disease activity in rheumatoid arthritis: evaluation of a functional test

A cross sectional analysis of the correlation between clinical, laboratory, and radiological markers of disease activity in 98 patients with classical rheumatoid arthritis (RA) is reported. The median age was 38 years, the median age at onset of disease 29 years, and the median duration of disease seven years. The Keitel function test (KFT) showed good correlation with the Ritchie articular index (RAI) (p less than 0.0001; r = 0.5) and the disability questionnaire (DQ) (p less than 0.0001; r = 0.6). The RAI and DQ correlated weakly with laboratory variables, while the KFT showed significant correlation with the erythrocyte sedimentation rate (ESR), C reactive protein (CRP), and plasma viscosity (PV) (p less than 0.001; r = 0.4; 0.3; 0.4). Only the KFT showed significant correlations with bone mass measurements (p less than 0.01; r = -0.3; -0.4), and the Larsen index at the right wrist (p less than 0.0001; r = 0.4). Consensus analysis suggested that the KFT is a useful single clinical test of disease activity in RA. The hand functional index (HFI), a component of the KFT, showed significant correlation with the total KFT (r = 0.9). Prospective drug trials are needed to establish the value of the HFI in the monitoring of patients with RA.

Early treatment of avascular necrosis in systemic lupus erythematosus.

Avascular necrosis (AVN) of the hips is associated with significant disability, and the majority of established cases require major surgery. In a retrospective analysis of 185 patients with systemic lupus erythematosus (SLE) 13 (7%) were found to have AVN. Of these, six had Raynauds phenomenon, all had been on corticosteroids, and one had digital vasculitis. The mean duration of corticosteroid therapy was two years (range four months to five years). Five patients developed AVN two to 10 years after discontinuing steroids. The mean duration of disease at the onset of AVN was 6.85 years (range 1-19 years), and the mean age at onset of AVN was 31 years. Ten patients had severe multisystem involvement. None of the patients abused alcohol. Surgery was performed on 11 hips. Three had total hip replacement for stages 3 and 4 and seven had core decompression for stages 1 and 2. AVN progressed in two (28%) of these patients. In another patient core decompression failed for technical reasons. She subsequently required total hip replacement. The early detection of AVN to avoid the need for major surgery is stressed.

Bone Mineral Density and Lifetime Physical Activity in South African Women

We investigated the relation between lifetime physical activity and bone mineral density (BMD) in South African women using data collected in a case-control study of breast cancer in relation to BMD. Subjects (n = 144) were of black African or mixed ancestral origin, and <60 years of age (mean age 42.6 ± 8.9 years). Cases had newly diagnosed breast cancer (n = 62) and controls were referred for conditions unrelated to BMD or breast cancer (n = 82). Physical activity data consisting of household, occupational and leisure-time activity, and activity for transport, were collected via questionnaire at 4 life stages (epochs), viz. 14–21, 22–34, 35–50, and 50+ years of age. Total energy (MET hrs) and peak strain scores were calculated. Lumbar spine and total proximal femur BMD were measured using dual-energy x-ray absorptiometry. BMD measures were similar between groups, therefore data were combined. BMD measures were unrelated to total lifetime physical activity. However, the major determinants of total proximal femur BMD included age, transport activity including walking and bicycling between the ages of 14 and 21 years, and current weight (adjusted r2 = 0.33, P < 0.0001). The major determinants of lumbar spine BMD included age, household energy expenditure between the ages of 14 and 21 years, and current weight (adjusted r2 = 0.23, P < 0.0001). Total peak bone strain score for activities between 14–21 years of age was also significantly correlated with lumbar spine BMD (r = 0.18, P < 0.05). Intraclass correlation coefficients to assess tracking of activity through epochs 1, 2, and 3 were high for total energy expenditure (0.96; 95%CI: 0.94–0.97), household (0.98; 95%CI: 0.97–0.99) and occupational activity (0.78; 95%CI: 0.71–0.84) and activity for transport (0.92; 95%CI: 0.89–0.94). These data suggest that walking or activities resulting in impact loading at a young age are associated with higher BMD in later years. In addition, our findings suggest tracking of physical activity over time.

Metacarpal bone mass in systemic lupus erythematosus

SummaryWe report the prevalence of metacarpal cortical thinning in systemic lupus erythematosus (SLE). Fifty-eight ambulant female patients attending a lupus clinic (mean age 32.4 years), were found to have significant thinning of metacarpal cortices (p<0.05) when compared with 63 normal females (mean age 34.1 years). However, metacarpal bone mass was within the normal range. Measurements were made at 6 metacarpals of the 2 hands using a computer-aided technique (digitized radiogrammetry). Femoral cortical width and Singh index at the left femur, as well as the vertebral index at L3 were also recorded. The trabecular indices were in the range of normality, but the SLE group had more patients in the immediately pre-osteopaenic range. Metacarpal bone loss was not related to disease duration or corticosteroid therapy. The prevalence of osteopenia in SLE is probably underestimated and the pathogenesis is likely to be multifactorial.

Prevalence of metacarpal osteopenia in young rheumatoid arthritis patients

SummaryThe aim of this study was to assess the prevalence of and diagnostic role of metacarpal osteopenia in rheumatoid arthritis (RA) and to evaluate its detectability using receiver operating characteristic (ROC) analysis. Metacarpal bone mineral density was measured in 98 patients with classical RA using a computer-assisted measure of 6 metacarpal diameters (radiogrammetry) in patients aged less than 50 years. Sensitivity and specificity of the technique in discriminating the RA patients from 85 normal controls and osteopenic RA subjects from their normopenic counterparts, was determined by standard statistical techniques. Clinical, laboratory and radiological variables were compared in their ability to explain the variance of metacarpal bone density. The prevalence of metacarpal osteopenia in RA was 55%. Prolonged disease and reduced function significantly differentiated osteopenic from non-osteopenic RA patients. Discriminant analysis of the RA and control groups showed that measurement of 6 metacarpals was more accurate than the 2nd metacarpal measurement alone in predicting the RA patients. The sum of 6 metacarpal combined cortical width (CCW) had a sensitivity of 61% and specificity of 68% in discriminating the RA patients from the controls. Receiver operating characteristic curves showed, not surprisingly, that objective measurement of bone diameters was superior to clinical or laboratory measures of disease activity in correctly classifying a randomly chosen RA patient as osteopenic or not. Metacarpal osteopenia is common in RA and it may be a useful measure of the disease in young patients.

A Risk-Benefit Assessment of Slow-Acting Antirheumatic Drugs in Rheumatoid Arthritis

SummaryThere is no ideal slow-acting antirheumatic drug. Therapy of rheumatoid arthritis (RA) is currently being modified, with strong recommendations to abandon the traditional pyramidal approach. The call is for a more aggressive, earlier approach to suppress inflammation. Combination therapy rather than the use of a single agent is advocated by some. Improved methods for assessing disease activity as well as measurement of outcome have been developed. Markers of poor prognosis have helped to define patients for earlier treatment. Comparison of toxicity among such a diverse group of drugs is probably best achieved with a toxicity index measuring the number of episodes expressed in terms of patient-years of exposure. Toxicity remains the commonest reason for discontinuing an agent, while remission beyond 36 months on therapy is uncommon, except with methotrexate. The profile of toxicity is clearly defined for individual agents, but combination therapy may reveal an entirely different set of toxic manifestations. There is an urgent need to develop a set of risk factors to predict toxicity in an individual patient. Juvenile chronic arthritis behaves differently from adult RA. Drug toxicity profiles are similar, but less common. Outcome is more difficult to measure, with the major impact of disease and therapy being on growth retardation.

Consultation outcomes for musculoskeletal conditions at two community health centres in Cape Town

Abstract Objectives: To compare the proportion of patients with documented diagnoses and management plans when they presented with musculoskeletal complaints at two community health centres (CHCs) using two models of care: one with a rheumatology outreach service and the other with none. Secondly, to describe the profile of patients with rheumatoid arthritis (RA) who attended the CHC with the outreach service. Design: Cross-sectional. Setting: Heidelberg Community Health Centre and Vanguard Community Health Centre, Cape Town. Subjects: A group of 59 patients at each CHC were compared regarding engagement of their musculoskeletal complaints by doctors and clinical nurse practitioners (CNPs). Secondly, 24 RA patients who attended Heideveld CHC were profiled. Results: A comparison of the “overall engagement” between the two CHCs [risk difference (RD) -0.06, 95% confidence interval (CI): -0.17–0.05, odds ratio (OR) 0.79, 95% CI: 0.51–1.24, chi-square 0.82, p-value 0.36] was not significantly different. Comparison between doctors (RD -0.05, 95% CI: -0.05–0.08, OR 0.80, 95% CI: 0.46–1.40, chi-square 0.41, p-value 0.52) was also not significantly different. The comparison between the CNPs at the two CHCs was statistically significant (RD 0.30, 95% CI: 0.14–0.45, OR 8.37, 95% CI: 1.05–66.60, Fishers exact test 0.01), but the CI around OR was large. Patients with RA had a mean age of 60 years, an average of two co-morbidities and an average of three annual clinic visits. Eighty- three per cent resided in the drainage area of the clinic. Conclusion: There was no significant difference in engagement between the CHCs. The potential that CNPs seemed to show of being positively influenced by the outreach service should be further researched. Patients with RA had co- morbidities that required management at primary healthcare level.

Quantitative Ultrasound in Relation to Risk Factors for Low Bone Mineral Density in South African Pre-Menopausal Women

SummaryThe study describes the association between risk factors and quantitative ultrasound bone measures in black and mixed-race pre-menopausal South African women. Despite some differences between the two study groups, the findings generally lend support to the use of ultrasound for epidemiological studies of bone mass in resource-limited settings.IntroductionQuantitative ultrasound at the calcaneus is a convenient and inexpensive method of estimating bone strength well suited to community-based research in countries with limited resources. This study determines, in a large sample of pre-menopausal South African women, whether characteristics associated with quantitative ultrasound measures are similar to those shown to be associated with bone mineral density as measured by dual X-ray absorptiometry.MethodsThis cross-sectional study included 3,493 women (1,598 black and 1,895 mixed race), aged 18–44 living in Cape Town. Study nurses administered structured interviews on reproductive history, lifestyle factors, and measured height and weight. Calcaneus quantitative ultrasound measurements were obtained using the Sahara device. Adjusted means of ultrasound measures according to categories of risk factors were obtained using multivariable regression analysis.ResultsAssociations between quantitative ultrasound measures and age, body mass index, age at menarche, parity, and primary school physical activity were similar to those known for bone mineral density as measured by dual X-ray absorptiometry. There were no clear associations between quantitative ultrasound measures and educational level, alcohol use, cigarette smoking, and current calcium intake.ConclusionThe data give qualified support to the use of quantitative ultrasound as an epidemiological tool in large studies of bone strength in pre-menopausal women.