Objective. To delineate daily and cumulative glucocorticoid dose thresholds associated with increased mortality rates in rheumatoid arthritis (RA).Methods. We studied RA patients recruited from rheumatology clinics. Annually, we assessed the glucocorticoid dose, demographic, socioeconomic, clinical, and laboratory features of RA, cardiovascular (CV) risk factors, and vital status. We used Cox proportional hazards regression to assess associations between the daily or cumulative glucocorticoid dose and death, adjusting for potential confounders and for the propensity to receive glucocorticoids. We tested strata of the glucocorticoid dose to delineate the threshold associated with death.Results. We studied 779 RA patients with a total of 7,203 person-years of observation, during which 237 of them died, yielding a mortality rate of 3.2 per 100 person-years (95% confidence interval [95% CI] 2.8-3.7). One hundred twenty of the deaths were due to CV causes, yielding a CV mortality rate of 1.8 (95% CI 1.5-2.1). Exposure to glucocorticoids was associated with a dose-dependent increase in death from all causes, with a ratio (HR) of 1.07 per mg of prednisone per day (95% CI 1.05-1.08). Compared to patients who were not receiving corticosteroids, the minimum daily prednisone dose threshold associated with an increase in all-cause mortality was 8-15 mg, with an adjusted HR of 1.78 (95% CI 1.22-2.60). For the cumulative dose of glucocorticoids, the minimum dosage associated with allcause mortality was 40 gm (HR 1.74 [95% CI 1.25- 2.44]).Conclusion. Glucocorticoid use in RA is associated with a dose-dependent increase in mortality rates, with a daily threshold dose of 8 mg, at which the number of deaths increased in a dose-dependent manner. These findings may assist clinicians in selecting the appropriate glucocorticoid dosage for RA patients who require these agents.
A reaction of urea, o-phthalaldehyde and N-(1-naphthyl)ethylenediamine is described for measurement of urea by manual, continuous-flow, and kinetic methods. The continuous-flow system requires 25 µl of sample; 40 samples can be analyzed per hour. The kinetic method requires no enzymes, has no lag phase, and has good sensitivity. A major advantage of the reaction is that it occurs at a temperature of 37 °C or lower. The results obtained by all three methods agree well with those for a continuous-flow procedure in which diacetyl is a reagent.
Objective-To test the hypothesis that early exercise training after myocardial infarction (MI) could preserve cardiac function, alleviate left ventricular (LV) remodeling and induce a protective effect on morphology.Methods-Male Sprague-Dawley rats underwent coronary ligation or sham operation, and were assigned to 3 groups: Sham, sedentary MI (SedMI), and exercise MI (ExMI). We measured the changes in collagen volume fraction, matrix metalloproteinase (MMP) 1, tissue inhibitor matrix metalloproteinase 1 (TIMP-1), angiotensin II receptor type 1 (AT1), and angiotensin converting enzyme (ACE) at gene and protein levels after 8 weeks of exercise training. Cardiac functions were determined by echocardiographic and hemodynamic measurements.Results-Early exercise training after MI had no effect on LV wall thinning. Cardiac function was significantly preserved in the ExMI group in comparison to the SedMI group. The collagen volume fraction in the ExMI group was significantly lower than in the SedMI group. Compared to the SedMI group, the ExMI group showed a markedly decrease at both the gene and protein levels in TIMP-1 (P<0.05). No significant differences were found in MMP-1 among the three groups. MMP-1/TIMP-1 ratio in the ExMI group was significantly higher than in the SedMI group. In addition, the expression of AT1 protein in the ExMI group was significantly lower than in the SedMI group. Furthermore, both ACE mRNA expression and ACE binding in the ExMI group are significantly decreased compared to the SedMI group.Conclusions-Our results suggest that early exercise training after MI reduces TIMP-1 expression, improves the balance between MMPs and TIMPs, and mitigates the expressions of ACE and AT1 receptor. These improvements, in turn, attenuate myocardial fibrosis and preserve post-MI cardiac function.
Objective To estimate atherosclerosis progression and identify influencing factors in rheumatoid arthritis (RA). Methods We used carotid ultrasound to measure intima-media thickness (IMT) in RA patients, and ascertained cardiovascular (CV) risk factors, inflammation markers and medications. A second ultrasound was performed approximately 3 years later. We calculated the progression rate by subtracting the baseline from the follow-up IMT, divided by the time between the two scans. We used logistic regression to identify baseline factors predictive of rapid progression. We tested for interactions of erythrocyte sedimentation rate (ESR) with CV risk factors and medication use. Results Results were available for 487 RA patients. The mean (SD) common carotid IMT at baseline was 0.571 mm (0.151). After a mean of 2.8 years, the IMT increased by 0.050 mm (0.055), p≤0.001, a progression rate of 0.018 mm/year (95% CI 0.016 to 0.020). Baseline factors associated with rapid progression included the number of CV risk factors (OR 1.27 per risk factor, 95% CI 1.01 to 1.61), and the ESR (OR 1.12 per 10 mm/h, 95% CI 1.02 to 1.23). The ESR×CV risk factor and ESR×medication product terms were significant, suggesting these variables modify the association between the ESR and IMT progression. Conclusions Systemic inflammation and CV risk factors were associated with rapid IMT progression. CV risk factors may modify the role of systemic inflammation in determining IMT progression over time. Methotrexate and antitumour necrosis factor agents may influence IMT progression by reducing the effect of the systemic inflammation on the IMT.
The application of left ventricular pressure-volume analysis to transgenic mice to characterize the cardiac phenotype has been problematic due to the small size of the mouse heart and the rapid heartbeat. Conductance technology has been miniaturized for the mouse and can solve this problem. However, there has been no validation of this technique. Accordingly, we performed echocardiography followed by simultaneous ultrasonic crystals, flow probe, and conductance studies in 18 CD-1 mice. Raw conductance volumes were corrected for an inhomogenous electrical field (alpha) and parallel conductance (G(pi)) yielding a stroke volume of 14.1 +/- 3.7 microliter/beat, end-diastolic volume of 20.8 +/- 6.5 microliter, and end-systolic volume of 9.0 +/- 5.8 microliter. The mean conductance volumes were no different from those derived by flow probe and echocardiography but did differ from ultrasonic crystals. G(pi) was determined to be 14.9 +/- 8.7 microliter. However, hypertonic saline altered dimension and pressure in the mouse left ventricle. Although G(pi) can be determined by the hypertonic saline method, saline altered hemodynamics, questioning its validity in the mouse. Although mean measures of absolute volume may be similar among different techniques, individual values did not correlate.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.