Muscle strength and bone density in patients with different rheumatic conditions: cross-sectional study

Aim

To explore the relationship between muscle strength and bone density in patients with different rheumatic diseases and to examine whether inflammatory arthritis was more harmful for muscle strength and bone loss than degenerative joint diseases.

Methods

The study included 361 men and women with a mean ± standard deviation age of 60.5 ± 11.4 years and different rheumatic conditions: regional syndromes, osteoarthritis of the hands, shoulders, knees, and hips, and inflammatory arthritis. Maximum voluntary back strength was measured by isometric dynamometry. Bone mineral density (BMD; g/cm²) of the lumbar spine, femoral neck, and distal radius was measured by dual-energy x-ray absorptiometry. Anthropometry and lifestyle characteristics were also assessed.

Results

Back strength was lowest in patients with hand and shoulder osteoarthritis (20.0 ± 17.9 kg), followed by patients with inflammatory arthritis (24.8 ± 19.2 kg). Patients with inflammatory arthritis had the lowest BMD at the mid-radius (0.650 ± 0.115 g/cm²) and femoral neck (0.873 ± 0.137 g/cm²), while patients with hand and shoulder osteoarthritis had the lowest BMD at the mid-radius (0.660 ± 0.101). In both sexes, muscle strength was significantly lower in patients who had lower BMD (T score<-1.0). Multiple regression analysis identified significant predictors of back strength to be spine BMD (P = 0.024) and body mass index (P = 0.004) in men and femoral neck BMD in women (P = 0.004).

Conclusion

Muscle strength decline may be connected to bone loss in patients with rheumatic conditions, especially those with inflammatory joint diseases.There is a concomitant decline in muscle strength of the upper and lower limbs and bone density after the fifth decade of the life (1,2). Impaired muscle function is a common consequence in patients with rheumatic diseases, especially those with inflammatory joint diseases. Muscle strength may also be significantly reduced around joints affected with osteoarthritis. Several studies showed greatly reduced isokinetic strength in patients with rheumatoid arthritis (3-5) and patients with knee osteoarthritis (6).It is also known that muscle strengthening can yield a bone-building effect (7). Exercises with greater loading and higher impact activities produce the greatest skeletal benefit (8). Increased muscle weakness can also compound the problem of low bone density by increasing the risk of falls and fracture. A positive correlation between muscle strength and bone density has been shown in several studies (9-17). Some of them demonstrated the association only in postmenopausal women (12,17) but not in men (9,13), while other found a site-specific correlation between muscle strength and bone mineral density (BMD) (4,12). However, several studies did not find a correlation between any measures of muscle strength and BMD (18,19). With such contradictory reports, it is difficult to make clinically relevant conclusions about the relationship between muscle strength and bone mass, although this may be one of the key factors that affect the rehabilitation outcome.The aim of the study was to assess the differences in muscle strength and bone density between patients with different rheumatic conditions. Since muscle strength is an important determinant of bone density, we explored whether the age-related decline in bone density and muscle strength was more pronounced in patients with inflammatory arthritis than in those with degenerative joint diseases.     

Nutrition and lifestyle in relation to bone health and body weight in Croatian postmenopausal women

The objective was to investigate the association of nutrients and lifestyle modifiers with bone mineral density (BMD) and weight and/or body mass index (BMI) in 120 healthy Croatian postmenopausal women. The hip and spine BMD was assessed by Lunar Prodigy (GE Medical Systems). Nutrient assessment from 3-day records was analyzed using the US Department of Agriculture Food Composition Tables and the Croatian National Institute of Public Health database. Subjects were asked to record the consumption of alcohol, coffee, tea and mineral waters, the amount of salt added to foods and smoking habits, as well as involvement in recreational activities, walking and heavy housework. Spot urine samples were analyzed for calcium, magnesium, sodium, potassium and zinc and were normalized by creatinine. Alcohol showed statistically significant positive association with femur and spine BMD and its consumption was higher in subjects without osteoporosis. Urinary sodium/creatinine was significantly positively associated with femoral neck and trochanter BMD, while urinary calcium/creatinine was significantly negatively associated with trochanter, total femur and spine BMD. Consumption of mineral waters was inversely associated with weight/BMI and so were dietary fiber and magnesium. In conclusion, moderate alcohol consumption and urinary sodium were positively associated while urinary calcium was negatively associated with either hip and/or spine BMD. Mineral waters, higher fiber and magnesium intake were beneficial for weight/BMI in this population of apparently healthy Croatian women.     

Lower life satisfaction,active coping and cardiovascular disease risk factors in older African Americans: outcomes of a longitudinal church-based intervention

This study examined lower life satisfaction, active coping and cardiovascular disease risk factors (diastolic and systolic blood pressure, body mass index, and circumferences) in older African Americans over the phases of an 18-month church-based intervention, using a quasi-experimental design. Participants (n = 89) were 45 years of age and older from six churches (three treatment, three comparison) in North Florida. Lower life satisfaction had a persistent unfavorable effect on weight variables. Active coping showed a direct beneficial effect on selected weight variables. However, active coping was adversely associated with blood pressure, and did not moderate the association between lower life satisfaction and cardiovascular risk factors. The intervention had a beneficial moderating influence on the association between lower life satisfaction and weight variables and on the association between active coping and these variables. Yet, this pattern did not hold for the association between active coping and blood pressure. The relationship of lower life satisfaction and selected cardiovascular risk factors and the positive effect of active coping were established, but findings regarding blood pressure suggest further study is needed.     

Effects of glucose-insulin-potassium infusion on ST-elevation myocardial infarction in patients treated with thrombolytic therapy

The role of glucose-insulin-potassium (GIK) infusion in the management of acute myocardial infarction is not well established. This prospective, randomized study comprised 120 patients who had ST-elevation myocardial infarction that was treated within 12 hours from symptom onset with a high dose of GIK (25% glucose, 50 IU of soluble insulin per liter, and 80 mmol of potassium chloride per liter at 1 ml/kg/hour over 24 hours) as adjunct to thrombolytic therapy (1.5 MU of streptokinase/30 to 60 minutes; GIK group) or thrombolytic therapy alone (control group). The primary end point of the study was the rate of major adverse cardiac events (MACEs) at 1 month, defined as a composite of cardiac death, reinfarction, serious arrhythmias (ventricular fibrillation and/or tachycardia), and severe heart failure. The secondary end points were the rate of MACEs at 1 year and improvement in left ventricular systolic function. The incidence of MACEs at 1 month was significantly lower in the GIK group (10% vs 32.5%, relative risk 0.24, 95% confidence interval 0.09 to 0.63, p = 0.0043). Patients in the GIK group had significant decreases in ventricular tachycardia and/or fibrillation (1.3% vs 15.0%, p = 0.003) and severe heart failure (3% vs 12.5%, p = 0.031). The rate of MACEs at 1 year was also significantly lower in the GIK group (13% vs 40.0%, relative risk 0.22, 95% confidence interval 0.09 to 0.55, p = 0.0012). After 1 year, there was a significant improvement in left ventricular ejection fraction in the GIK group (from 48 +/- 8% to 51 +/- 10%, p <0.01), which was not observed in the control group. In conclusion, high-dose GIK, used as an adjunct to thrombolytic therapy, was safe and improved clinical outcome at 1 month. The beneficial effect of GIK infusion was maintained up to 1 year.     

Angiogenesis and Ewing sarcoma--relationship to pulmonary metastasis and survival

Background/Purpose

Intratumoral angiogenesis quantified by microvessel density (MVD) has been shown to be a strong prognostic indicator in a number of malignant tumors. Its association with prognosis in Ewing sarcoma has not been previously studied. The aim of our study was to investigate the relationship between angiogenesis and clinical outcome in Ewing sarcoma.

Methods

Twenty-seven patients with Ewing sarcoma were included in a retrospective immunohistochemical study. Sections from diagnostic biopsies were immunostained using anti-von Willebrand factor antibody and microvessels were counted at 400× magnification on three microscopic fields per patient. Microvessel density was correlated with overall and disease-free survival as a continuous variable using univariate regression analysis and as a dichotomous variable by Kaplan-Meier and log-rank analysis. Correlation between clinicopathologic variables and the degree of angiogenesis was tested using χ² test.

Results

Increasing MVD was not confirmed to be a poor prognostic factor in univariate analysis. Also, statistically significant difference was not found in overall survival or disease-free survival between patients with high (>31.6 vessels per field) and low (≤31.6 vessels per field) microvessel counts. Finally, there was no difference regarding the metastatic rate between patients with high and low microvessel counts.

Conclusions

Our results did not confirm increasing angiogenesis quantified by MVD to be predictive of prognosis or pulmonary metastasis in Ewing sarcoma. The diffuse pattern of distribution of microvessels found in Ewing sarcoma may be responsible for the observed lack of prognostic significance of angiogenesis. Future work is required to assess the prognostic importance of MVD in this disease.     

Enhanced CD4+ cellular apoptosis by CCR5-restricted HIV-1 envelope glycoprotein variants from patients with progressive HIV-1 infection

CCR5-using (R5) human immunodeficiency virus type 1 (HIV-1) strains cause CD4+ T-cell loss in most infected individuals, but mechanisms underlying cytopathicity of R5 viruses are poorly understood. We investigated mechanisms contributing to R5 envelope glycoprotein (Env)-mediated cellular apoptosis by constructing a panel of retroviral vectors engineered to co-express GFP and R5 Envs derived from two HIV-1-infected subjects spanning asymptomatic (Early, E-R5 Envs) to late stages of infection (Late, L-R5 Envs). The L-R5 Envs induced significantly more cellular apoptosis than E-R5 Envs, but only in Env-expressing (GFP-positive) cells, and only in cells where CD4 and CCR5 levels were limiting. Studies with fusion-defective Env mutants showed induction of apoptosis required membrane-fusing events. Our results provide evidence for an intracellular mechanism of R5 Env-induced apoptosis of CD4+ cells that requires membrane fusion. Furthermore, they contribute to a better understanding of mechanisms involved in CD4+ T-cell loss in subjects experiencing progressive R5 HIV-1 infection.     

Competency in cardiac examination skills in medical students, trainees, physicians, and faculty: a multicenter study

BACKGROUND: Cardiac examination is an essential aspect of the physical examination. Previous studies have shown poor diagnostic accuracy, but most used audio recordings, precluding correlation with visible observations. The training spectrum from medical students (MSs) to faculty has not been tested, to our knowledge. METHODS: A validated 50-question, computer-based test was used to assess 4 aspects of cardiac examination competency: (1) cardiac physiology knowledge, (2) auditory skills, (3) visual skills, and (4) integration of auditory and visual skills using computer graphic animations and virtual patient examinations (actual patients filmed at the bedside). We tested 860 participants: 318 MSs, 289 residents (225 internal medicine and 64 family medicine), 85 cardiology fellows, 131 physicians (50 full-time faculty, 12 volunteer clinical faculty, and 69 private practitioners), and 37 others. RESULTS: Mean scores improved from MS1-2 to MS3-4 (P = .003) but did not improve or differ significantly among MS3, MS4, internal medicine residents, family medicine residents, full-time faculty, volunteer clinical faculty, and private practitioners. Only cardiology fellows tested significantly better (P<.001), and they were the best in all 4 subcategories of competency, whereas MS1-2 were the worst in the auditory and visual subcategories. Participants demonstrated low specificity for systolic murmurs (0.35) and low sensitivity for diastolic murmurs (0.49). CONCLUSIONS: Cardiac examination skills do not improve after MS3 and may decline after years in practice, which has important implications for medical decision making, patient safety, cost-effective care, and continuing medical education. Improvement in cardiac examination competency will require training in simultaneous audio and visual examination in faculty and trainees.     

Is the prevalence of arterial hypertension in rheumatoid arthritis and osteoarthritis associated with disease?

In this study, we compare the prevalence of arterial hypertension (HT) in rheumatoid arthritis (RA) and osteoarthritis (OA) patients, exposed to high- and low-grade chronic inflammation, respectively, to assess the possible association between chronic inflammation and HT. A total of consecutive 627 RA and 352 OA patients were enrolled in this multicentric study. HT was defined as a systolic blood pressure (BP) ≥ 140 and/or diastolic BP ≥ 90 mmHg or current use of any antihypertensive drug. Overweight/obesity was defined as body mass index (BMI) ≥ 25, and patients ≥65 years were considered elderly. The prevalence of HT was higher in the OA group than in the RA group [73.3 % (95 % CI, 68.4, 77.7) and 59.5 % (95 % CI, 55.6, 68.4) P < 0.001, respectively]. When the results were adjusted for age and BMI, the HT prevalence was similar in both groups [RA 59 % (95 % CI, 55.1, 63.8) OA 60 % (95 % CI, 58.4, 65.0)]. In both groups, the prevalence of HT was higher in the elderly and those who were overweight than in the younger patients and those with a BMI < 25. Overweight (BMI ≥ 25) and age ≥65 were independent predictors of HT in multivariate logistic regression model, which showed no association between HT and the disease (RA or OA). The results indicate a robust association of age and BMI with HT prevalence in both RA and OA. The difference in HT prevalence between RA and OA is due rather to age and BMI than to the features of the disease, putting into question specific association of HT with RA.