Heart failure is associated with low circulating levels of secreted frizzled receptor protein 5 (Sfrp5)

Background/Introduction

Obesity and metabolic dysregulation are closely associated with the pathophysiology of multiple cardiovascular diseases (CVD). To date, the pathophysiological mechanism(s) of obesity and its link with cardiovascular systems remain largely unknown. Adipose tissue inflammation as a result of excessive fat expansion in obesity, leading to increased systemic production of growth factors and recruitment of inflammatory cells have been postulated to be a major factor. Secreted frizzled-related protein 5 (SFRP5) is an anti-inflammatory adipokine that is linked with obesity and metabolic regulation and has been indicated to affect cardiovascular functions. Currently, the role of circulating SFRP5 levels as a biomarker for cardiovascular diseases are poorly understood, with studies yielding discordant results.

Purpose

This study aims to evaluate the relationship between circulating SFRP5 and cardiovascular functions in a cohort of patients with established CVD.

Methods

Patients (n=262, 148 male (56.5%), age (68±11 yrs)) presenting to the cardiology unit for cardiovascular investigations were recruited into the study. Plasma SFRP5 levels were measured via enzyme-linked immunosorbent assay (ELISA). Associations between plasma SFRP5 levels, cardiovascular functions, and patients' co-morbidities were analysed using univariate and multivariate analyses.

Results

Plasma SFRP5 levels were significantly lower in patients presenting with: heart failure (HF) vs non-HF (median; (10.7 vs 31.0; p<0.001); coronary artery disease (CAD) vs non-CAD; (11.0 vs 33.8; p<0.001); and atrial fibrillation (AF) vs non-AF; (11.2 vs 23.2; p=0.001). On univariate analyses, SFRP5 levels also significantly positively correlated with left ventricular ejection fraction (LVEF) (r=0.52, p<0.001), estimated glomerular filtration rate (eGFR) (r=0.16, p=0.02), total cholesterol levels and triglycerides (r=0.29, p<0.001; r=0.17, p<0.01 respectively). Low SFRP5 levels were correlated with high C-reactive protein (CRP) and E/E' (r=−0.29, p<0.001, r=−0.30, p<0.001, respectively). Patients with HF, CAD, statin use, low LVEF, low triglycerides, high CRP and high eGFR were associated with lower SFRP5 levels independent of age, BMI or diabetes on multivariate analysis (overall model r=0.729, SE=0.638).

Conclusion

Our results show that low plasma SFRP5 levels are independently associated with HF, CAD, and impaired systolic and diastolic functions. These results suggest that SFRP5 may regulate cardiovascular functions independent of obesity and metabolic regulations.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Heart Foundation of Australia Future Leader FellowshipsNSW Ministry of Health EMC FellowshipHeart Foundation of Australia Future Leader Fellowship

Panic disorder and incident coronary heart disease: a systematic review and meta-regression in 1131612 persons and 58111 cardiac events

BACKGROUND

Substantial healthcare resources are devoted to panic disorder (PD) and coronary heart disease (CHD); however, the association between these conditions remains controversial. Our objective was to conduct a systematic review of studies assessing the association between PD, related syndromes, and incident CHD.

METHOD

Relevant studies were retrieved from Medline, EMBASE, SCOPUS and PsycINFO without restrictions from inception to January 2015 supplemented with hand-searching. We included studies that reported hazard ratios (HR) or sufficient data to calculate the risk ratio and 95% confidence interval (CI) which were pooled using a random-effects model. Studies utilizing self-reported CHD were ineligible. Twelve studies were included comprising 1 131 612 persons and 58 111 incident CHD cases.

RESULTS

PD was associated with the primary incident CHD endpoint [adjusted HR (aHR) 1.47, 95% CI 1.24-1.74, p < 0.00001] even after excluding angina (aHR 1.49, 95% CI 1.22-1.81, p < 0.00001). High to moderate quality evidence suggested an association with incident major adverse cardiac events (MACE; aHR 1.40, 95% CI 1.16-1.69, p = 0.0004) and myocardial infarction (aHR 1.36, 95% CI 1.12-1.66, p = 0.002). The risk for CHD was significant after excluding depression (aHR 1.64, 95% CI 1.45-1.85) and after depression adjustment (aHR 1.38, 95% CI 1.03-1.87). Age, sex, length of follow-up, socioeconomic status and diabetes were sources of heterogeneity in the primary endpoint.

CONCLUSIONS

Meta-analysis showed that PD was independently associated with incident CHD, myocardial infarction and MACE; however, reverse causality cannot be ruled out and there was evidence of heterogeneity.

Simplification of an erythropoiesis model for design of anemia management protocols in end stage renal disease

Many end stage renal disease (ESRD) patients suffer from anemia due to insufficient endogenous production of erythropoietin (EPO). The discovery of recombinant human EPO (rHuEPO) over 30 years ago has shifted the treatment of anemia for patients on dialysis from blood transfusions to rHuEPO therapy. Many anemia management protocols (AMPs) used by clinicians comprise a set of experience-based rules for weekly-to-monthly titration of rHuEPO doses based on hemoglobin (Hgb) measurements. In order to facilitate the design of an AMP based on formal control design methods, we present a physiologically-relevant erythropoiesis model, and show that its nonlinear dynamics can be approximated using a static nonlinearity, a step that greatly simplifies AMP design. We demonstrate applicability of our results using clinical data.

The calcium scare--what would Austin Bradford Hill have thought?

Detailed consideration of the suggested association between calcium supplementation and heart attacks has revealed weakness in the evidence which make the hypothesis highly implausible.

INTRODUCTION

The aim of this study was to evaluate the strength of the evidence that calcium supplementation increases the risk of myocardial infarction.

METHODS

This study used critical examination of a meta-analysis of the effects of calcium supplements on heart attacks in five prospective trials on 8,016 men and women, and consideration of related publications by the same author.

RESULTS

The meta-analysis was found to be subject to several limitations including non-adherence to the clinical protocol, multiple endpoint testing and failure to correctly adjust for endpoint ascertainment. The main risk factors for myocardial infarction were not available for 65% of the participants, and none of the trials had cardiovascular disease as its primary endpoint. There were more overweight participants, more subjects on thyroxine and more men on calcium than on placebo. In particular, over 65% of all the heart attacks were self-reported. When the evidence was considered in the light of Austin Bradford Hill's six main criteria for disease causation, it was found not to be biologically plausible or strong or to reflect a dose-response relationship or to be consistent or to reflect the relationship between the trends in calcium supplementation and heart attacks in the community or to have been confirmed by experiment. The addition of a more recent trial on 1,460 women over 5 years reduced the relative risk to 1.23 (P = 0.0695).

CONCLUSION

Present evidence that calcium supplementation increases heart attacks is too weak to justify a change in prescribing habits.

Accuracy and optimal timing of activity measurements in estimating the absorbed dose of radioiodine in the treatment of Graves' disease

Calculation of the therapeutic activity of radioiodine (131)I for individualized dosimetry in the treatment of Graves' disease requires an accurate estimate of the thyroid absorbed radiation dose based on a tracer activity administration of (131)I. Common approaches (Marinelli-Quimby formula, MIRD algorithm) use, respectively, the effective half-life of radioiodine in the thyroid and the time-integrated activity. Many physicians perform one, two, or at most three tracer dose activity measurements at various times and calculate the required therapeutic activity by ad hoc methods. In this paper, we study the accuracy of estimates of four 'target variables': time-integrated activity coefficient, time of maximum activity, maximum activity, and effective half-life in the gland. Clinical data from 41 patients who underwent (131)I therapy for Graves' disease at the University Hospital in Pisa, Italy, are used for analysis. The radioiodine kinetics are described using a nonlinear mixed-effects model. The distributions of the target variables in the patient population are characterized. Using minimum root mean squared error as the criterion, optimal 1-, 2-, and 3-point sampling schedules are determined for estimation of the target variables, and probabilistic bounds are given for the errors under the optimal times. An algorithm is developed for computing the optimal 1-, 2-, and 3-point sampling schedules for the target variables. This algorithm is implemented in a freely available software tool. Taking into consideration (131)I effective half-life in the thyroid and measurement noise, the optimal 1-point time for time-integrated activity coefficient is a measurement 1 week following the tracer dose. Additional measurements give only a slight improvement in accuracy.

T1-weighted cine FLASH is superior to IR imaging of post-infarction myocardial viability at 4.7T

PURPOSE

Data are unavailable for rational selection of pulse sequences to assess postinfarction myocardial viability in rodents at high field strength. We implemented a widely used clinical inversion recovery (IR) sequence at 4.7T and compared the results to a heavily T1-weighted cine FLASH sequence (T1-CF) for assessment of infarction size.

MATERIALS AND METHODS

Eleven infarcted rats were examined within 24 h of infarction after injection of Gadophrin-3 contrast agent. Images were acquired using both pulse sequences and a standard cine (SC) sequence. Estimates of infarct size were compared to TTC. Global LV function was compared between the T1-CF and SC sequences.

RESULTS

SNR, relative SNR, and CNR for the infarcted and normal myocardium were significantly greater for the IR sequence. Infarction size was overestimated by both sequences, but correlated highly and showed very close agreement with TTC. Global function revealed no significant differences between T1-CF and SC.

CONCLUSION

Both IR and T1-CF produced reliable results for assessment of infarction size at 4.7T. While the IR sequence delivers better overall SNR and CNR, the T1-CF allows concomitant assessment of global cardiac function with a much shorter acquisition time.

A phase I study of temozolomide (TMZ) and the farnesyltransferase inhibitor (FTI), lonafarnib (Sarazar, SCH66336) in recurrent glioblastoma

1556

Background: Farnesylation is essential for the post-translational modification of several proteins that play a role in cell proliferation and growth. FTIs demonstrate antiproliferative effects in a variety of tumor cell lines and xenograft models and enhanced efficacy by combining lonafarnib with TMZ compared with TMZ alone. Clinical studies show that dose-intense TMZ may have better efficacy then conventional dosing (Wick, Neurology 2004). Objective: Determine the maximum tolerated dose of lonafarnib when combined with a dose-intensified schedule of TMZ. Eligibility criteria: Histologically proven GBM; evidence of relaspe or progression; up to 2 prior chemotherapy regimens, prior TMZ permitted; KPS ≥ 60. No enzyme-inducing anticonvulsants. Methods: TMZ was given at 150 mg/m2 days 1–7 and 15–21; lonafarnib escalated by cohort: 100 mg BID, 150 mg BID, 200 mg BID on days 8–14 and 22–28 of a 28-day cycle. Response: Toxicity measured after cycle 1 using NCI CTCAE v3. Patient (pt)accrual used a 3 + 3 design. Response was evaluated q2 cycles. Standard response criteria (MacDonald) were used. Results: 15 patients were accrued. Median age 47 yrs; median KPS 90. M:F ratio was 11:4. No DLTs in any dose cohort, a pt (cohort 1) died day 29 of unrelated cardiac disease. 4 pts demonstrated partial response, all with prior TMZ failure, 3 pts showed prolonged stable disease. 6-month PFS rate estimated at 33%, median PFS 14 weeks. Treatment was well tolerated: 1 episode each of grade 3 diarrhea, esophagitis, fatigue and hypokalemia; 3 episodes of grade 3/4 leukopenia, 2 episodes of grade 3/4 neutropenia, and 2 episodes of grade 4 thrombocytopenia. Seven pts had grade 3/4 lymphopenia, some with persistant lymphopenia from prior TMZ. 1 pt had grade 4 pneumonitis of uncertain etiology. Conclusions: The alternating week schedule of TMZ/lonafarnib was well tolerated. Preliminary results suggest anti-tumor activity even in pts who had failed prior TMZ. It is not certain whether this activity is due to the dose-intensified TMZ or the treatment combination. Studies are planned to evaluate potential predictors of response (i.e MGMT gene promoter methylation) and expand the trial to obtain pharmacokinetic and additional efficacy data.

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Mycoplasma fermentans inhibits tumor necrosis factor alpha-induced apoptosis in the human myelomonocytic U937 cell line

Mycoplasma fermentans (M. fermentans) was shown to be involved in the alteration of several eukaryotic cell functions (i.e. cytokine production, gene expression), and was suggested as a causative agent in arthritic diseases involving impaired apoptosis. We investigated whether M. fermentans has a pathogenic potential by affecting tumor necrosis factor (TNF)alpha-induced apoptosis in the human myelomonocytic U937 cell line. A significant reduction in the TNFalpha-induced apoptosis (approximately 60%) was demonstrated upon either infection with live M. fermentans or by stimulation with non-live M. fermentans. To investigate the mechanism of M. fermentans antiapoptotic effect, the reduction of mitochondrial transmembrane potential (DeltaPsim) and the protease activity of caspase-8 were measured. In the infected cells, the reduction of DeltaPsim was inhibited (approximately 75%), and an approximately 60% reduction of caspase-8 activity was measured. In conclusion, M. fermentans significantly inhibits TNFalpha-induced apoptosis in U937 cells, and its effect is upstream of the mitochondria and upstream of caspase-8.