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Biomedical subjects

Michael Sosin

Publications and source records attributed to Michael Sosin.

6 recordsLinked to original sources
PubMed2006

Raised leptin concentrations among South Asian patients with chronic heart failure.

BACKGROUND: The disease presentation of chronic heart failure (CHF) is considered to progress with metabolic deterioration, underlined by changes in adipose associated hormones (adipocytokines). However, little is known about ethnic variations of adipocytokines amongst CHF patients, in particular South Asians, who are at an increased risk of CHF. METHODS: Using a cross-sectional study, South Asians (n=106) and Caucasians (n=105) living in the UK were compared by CHF status. We investigated ethnic differences in adipocytokines (leptin, adiponectin, tumor necrosis factor (TNF)alpha), and their association with CHF. Patients with mild to moderate CHF were recruited from heart failure clinics (47 Caucasian, 54 South Asian), and compared to healthy controls. Metabolic parameters (including insulin resistance using HOMA modelling), echocardiography and brain natriuretic peptide (BNP) were measured amongst patients and healthy controls, and compared across and within ethnic groups. RESULTS: Mean (log transformed) plasma leptin concentrations were highest amongst South Asian patients, being 5.25% (95%CI: 1.50-9.02) higher than Caucasian patients (P=0.007), and similarly raised with respect to controls (P< or =0.04). Indices of insulin resistance were higher amongst CHF patients compared with controls, with no ethnic variation. In addition to age, female gender and body-mass index, levels of leptin were also associated with South Asian ethnicity (P<0.001), insulin resistance (P=0.02), smoking habit (P=0.01) and HDL cholesterol (P=0.004). Levels of adiponectin showed no ethnic variation, but were associated with CHF and a previous history of myocardial infarction (P<0.001). On multivariate regression analysis of patients and healthy controls, CHF was independently associated with smoking habit, adiponectin and insulin resistance (all P<0.01). CONCLUSION: Metabolic abnormalities are present in CHF, which in turn, are influenced by ethnicity. The role of adipocytokines in CHF pathophysiology and prognosis merits further study.

Adiponectin↗
PubMed2005

Markers of inflammation in acute coronary syndromes: association with increased heart rate and reductions in heart rate variability.

BACKGROUND: Systemic and vascular inflammation is at the heart of the thrombotic occlusion of coronary arteries. HYPOTHESIS: The study was undertaken to determine the relationship between established inflammatory markers (interleukin-6 [IL-6] and high-sensitivity C-reactive protein [hs-CRP]), neutrophil or white cell count, and concomitant autonomic tone in patients with coronary artery disease soon after occlusive events. METHODS: We tested the linkage between autonomic tone (as defined using both time domain and frequency domain estimates of heart rate variability [HRV]) and circulating markers of inflammation (white cell counts, hs-CRP, and IL-6) in a sample of 100 patients with proven acute coronary syndrome and compared these with healthy controls (n = 49) and the relationships on repeated measures at 4 months in recovery (n = 51). RESULTS: We demonstrated predictable depressed HRV in acute patients who tended to show recovery by 4 months. The acute changes in HRV indices (e.g., triangular index) showed modest negative correlation (r = -0.2-0.3) with the acute elevation of white cell count, IL-6, and hs-CRP. These associations did not persist on multivariate analysis of data gathered at 4 months post event. CONCLUSION: These observational data, while limited, are the first to link autonomic tone and in particular sympathetic tone (as indicated by HRV), to the process of acute leukocytosis and systemic inflammation common in acute coronary syndromes.

Biomarkers↗
PubMed2005

Hibernating myocardium in heart failure.

Ischemic left ventricular systolic dysfunction may result from myocardial necrosis or from hypocontractile areas of viable myocardium. In some cases, recovery of contractility may occur on revascularization--this reversibly dysfunctional tissue is commonly referred to as hibernating myocardium. Observational data suggest that revascularization of patients with ischemic left ventricular systolic dysfunction and known viable myocardium provides a survival benefit over medical therapy. Identification of viable, dysfunctional myocardium may be especially worthwhile in deciding which patients with ischemic left ventricular systolic dysfunction will benefit from revascularization procedures. Randomized, prospective trials evaluating this are currently ongoing. This review will provide an overview of the complex pathophysiology of viable, dysfunctional myocardium, and will discuss outcomes after revascularization. Of the techniques used to determine the presence of hibernating myocardium, functional methods such as stress echocardiography and cardiac magnetic resonance appear more specific, but less sensitive, than the nuclear modalities, which assess perfusion and metabolic activity. Currently, the availability of all methods is variable.

Heart Failure↗