Decrease of thyroid function after ischemic stroke is related to stroke severity.

BACKGROUND: Thyroid hormones are of fundamental importance for brain function. While low triiodothyronine levels during acute ischemic stroke (AIS) are associated with worse clinical outcomes, dynamics of thyroid function after AIS remains unknown. Thus, we longitudinally evaluated thyroid hormones after stroke and related them to stroke severity. METHODS: We prospectively traced thyroid stimulating hormone (TSH), free triiodothyronine (fT3), and free thyroxin (fT4) levels from the hyper-acute (within 24 h) to acute (3-5 days) and chronic (3-6 months) stages of ischemic stroke using a mixed regression model. Then, we analyzed whether stroke severity at presentation, expressed by National Institute of Health Stroke Scale (NIHSS), is associated with change in thyroid function. RESULTS: Forty-five patients were evaluated in hyper-acute and acute stages, while 29 were followed through chronic stage. TSH levels decreased from hyper-acute (2.91 ± 0.65 µIU/mL) to acute (2.86 ± 0.46 µIU/mL) and chronic stages of stroke (1.93 ± 0.35 µIU/m, p = 0.95). fT3 levels decreased from hyper-acute (2.79 ± 0.09 pg/ml) to acute (2.37 ± 0.07 pg/ml) stages, but recovered in chronic stage (2.78 ± 0.10 pg/ml, p < 0.01). fT4 levels decreased from hyper-acute (1.64 ± 0.14 ng/dl) to acute (1.13 ± 0.03 ng/dl) stages, and increased in the chronic stage (1.16 ± 0.08 ng/dl, p = 0.02). One-unit increase in presenting NIHSS was associated with 0.04-unit decrease of fT3 from hyper-acute to the acute stage (p < 0.01). CONCLUSION: There is a transient decrease of thyroid hormones after ischemic stroke, possibly driven by stroke severity. Larger studies are needed to validate these findings. Correction of thyroid function in acute stroke may be investigated to improve stroke outcomes.

Low clusterin levels in high-density lipoprotein associate with insulin resistance, obesity, and dyslipoproteinemia.

OBJECTIVE: To determine whether obesity and insulin resistance associate with changes in the protein content of high-density lipoprotein (HDL) in 2 different groups of men by using targeted proteomics. METHODS AND RESULTS: Insulin resistance and obesity are hallmarks of type 2 diabetes mellitus and the metabolic syndrome, which confer an increased risk of cardiovascular disease. Recent studies suggest that the protein cargo of HDL makes important contributions to the lipoprotein's cardioprotective effects. In a discovery study, we used isotope dilution mass spectrometry to quantify the relative concentrations of 5 proteins previously implicated in HDL's cardioprotective effects in 3 groups of healthy subjects: lean insulin-sensitive, lean insulin-resistant, and obese insulin-resistant individuals. We validated our findings in a different group of subjects. The clusterin concentration in HDL strongly and negatively associated with insulin resistance and body mass index in both populations. HDL clusterin levels were lower in subjects with low HDL and high triglycerides, key components of the metabolic syndrome. There was an inverse correlation between clusterin levels in HDL and very-low-density lipoprotein/low-density lipoprotein. CONCLUSIONS: Clusterin levels in HDL are lower in men with reduced insulin sensitivity, higher body mass index, and an unfavorable lipid profile. Our observations raise the possibility that clusterin depletion contributes to the loss of HDL's cardioprotective properties.

Assessing diabetes-related knowledge among internal medicine residents using multiple-choice questionnaire.

BACKGROUND: To design a comprehensive tool to assess the knowledge of pathophysiology, diagnosis, treatment, and care of patients with diabetes mellitus among medical students (MS) and residents and to evaluate this tool in a hospital setting. METHODS: A multiple-choice questionnaire with 21 questions was designed and administered to MS and residents. Cronbach alpha test was used to assess the internal consistency of the questionnaire, and chi2 analysis was used to test statistically significant difference among different groups. RESULTS: A total of 4 groups of MS, 15 postgraduate year 1 (PGY1), 8 PGY2, 4 PGY3, and 3 PGY4 participated in the study. The survey showed a good overall internal consistency (Cronbach alpha = 0.5). The percent of correct responses for MS, PGY1, PGY2, PGY3, and PGY4 were 75 +/- 4.2%, 79.8 +/- 13.5%, 81.5 +/- 16.1%, 85.6 +/- 12.3%, and 88.4 +/- 12.8%, respectively. CONCLUSIONS: We successfully designed and administered a diabetes knowledge assessment tool. This novel tool can be used in different settings to assess knowledge about important components of diabetes care among housestaff and steer practice-based learning. We observed trends toward improving level of knowledge with increase in the duration of training.

Consequences of unlocking the cardiac myosin molecule in human myocarditis and cardiomyopathies.

Myocarditis, often initiated by viral infection, may progress to autoimmune inflammatory heart disease, dilated cardiomyopathy and heart failure. Although cardiac myosin is a dominant autoantigen in animal models of myocarditis and is released from the heart during viral myocarditis, the characterization, role and significance of anti-cardiac myosin autoantibodies is poorly defined. In our study, we define the human cardiac myosin epitopes in human myocarditis and cardiomyopathies and establish a mechanism to explain how anti-cardiac myosin autoantibodies may contribute to heart disease. We show that autoantibodies to cardiac myosin in sera from myocarditis and dilated cardiomyopathies in humans targeted primarily epitopes in the S2 hinge region of cardiac myosin. In addition, anti-cardiac myosin antibodies in sera or purified IgG from myocarditis and cardiomyopathy targeted the beta-adrenergic receptor and induced antibody-mediated cAMP-dependent protein kinase A (PKA) cell signaling activity in heart cells. Antibody-mediated PKA activity in sera was abrogated by absorption with anti-human IgG. Antibody-mediated cell signaling of PKA was blocked by antigen-specific inhibition by human cardiac myosin or the beta-adrenergic receptor but not the alpha adrenergic receptor or bovine serum albumin. Propranolol, a beta blocker and inhibitor of the beta-adrenergic receptor pathway also blocked the antibody-mediated signaling of the beta-adrenergic receptor and PKA. The data suggest that IgG antibody against human cardiac myosin reacts with the beta-adrenergic receptor and triggers PKA signaling in heart cells. In summary, we have identified a new class of crossreactive autoantibodies against human cardiac myosin and the beta-adrenergic receptor in the heart. In addition, we have defined disease specific peptide epitopes in the human cardiac myosin rod S2 region in human myocarditis and cardiomyopathy as well as a mechanistic role of autoantibody in the pathogenesis of disease.

Increased serum pigment epithelium derived factor levels in Type 2 diabetes patients.

Serum PEDF levels (mean (S.D.)) were increased in 96 Type 2 diabetic vs. 54 non-diabetic subjects; 5.3 (2.8) vs. 3.2 (2.0)mug/ml, p<0.001. In diabetes, PEDF correlated with BMI, serum creatinine and LDL-cholesterol, but not with other lipids, HbA1c or CRP. PEDF did not differ by drugs, complications, or gender.

Coated-platelet levels in patients with Type 1 and with Type 2 diabetes mellitus.

Coated-platelet levels were quantified in 58 people with Type 1 diabetes, 90 with Type 2 diabetes, and 54 non-diabetic controls. In diabetes high coated-platelet levels were related to smoking and glucose control drugs, but not to glycaemia or other drugs. Prospective studies should evaluate coated-platelets and complications and drug effects.