Deformation of a renormalization-group equation applied to infinite-order phase transitions

By adding a linear term to a renormalization-group equation in a system exhibiting infinite-order phase transitions, asymptotic behavior of running coupling constants is derived in an algebraic manner. A benefit of this method is presented explicitly using several examples.Comment: 6 pages, 5 figures, revtex4, typo corrected, references adde

Hepatic lipase: a pro- or anti-atherogenic protein?

Hepatic lipase (HL) plays a role in the metabolism of pro- and anti-atherogenic lipoproteins affecting their plasma level and composition. However, there is controversy regarding whether HL accelerates or retards atherosclerosis. Its effects on different lipoprotein classes show that, potentially, HL may promote as well as decrease atherogenesis. Studies in animals with genetically modulated HL expression show that it depends on the model used whether HL acts pro- or anti-atherogenic. In humans, HL activity seems to correlate inversely with atherosclerosis in (familial) hypercholesterolemia, and positively in hypertriglyceridemia. In normolipidemia, HL activity is weakly associated with coronary artery disease (CAD). Genetically low or absent HL activity is usually associated with increased CAD risk, especially if plasma lipid transport is impaired due to other factors. Since HL promotes the uptake of lipoproteins and lipoprotein-associated lipids, HL may affect intracellular lipid content. We hypothesize that the prime role of HL is to maintain, in concert with other factors (e.g., lipoprotein receptors), intracellular lipid homeostasis. This, and the uncertainties about its impact on human atherosclerosis, makes it difficult to predict whether HL is a suitable target for intervention to lower CAD risk. First, the physiological meaning of changes in HL activity under different conditions should be clarified

Normotensive women with type 2 diabetes and microalbuminuria are at high risk for macrovascular disease

OBJECTIVE - The excess risk of macrovascular disease and death associated with diabetes seems higher in women than in men. The pathogenesis for this risk difference has not been fully elucidated. We investigated whether female sex was associated with macrovascular disease and death, independently of known risk factors related to type 2 diabetes, nephropathy, or retinopathy in normotensive patients with type 2 diabetes and microalbuminuria. RESEARCH DESIGN AND METHODS - We conducted a prospective, prolonged follow-up study of a subgroup of 67 diabetic patients (46 men and 21 women) without established cardiovascular disease who participated in a larger clinical trial. Data were collected on current and past health, medication use, blood pressure, renal function, and HbA1c during the follow-up period of 4.7 ± 0.8 (means ± SE) years. The end point was a composite of death, cardiovascular disease, cerebrovascular events, and peripheral artery disease. RESULTS - Of the women, eight (38.1%) met the end point compared with six (13.4%) of the men (P = 0.02 for difference in event-free survival). The hazard ratio of women relative to men was 3.19 (95% CI 1.11-9.21), which further increased after adjusting for age, systolic blood pressure, BMI, smoking, total-to-HDL cholesterol ratio, urinary albumin excretion, and retinopathy. CONCLUSIONS - In our study population of normotensive patients with type 2 diabetes and microalbuminuria, female sex was associated with increased risk of fatal and nonfatal cardiovascular disease, independent of the classical cardiovascular risk factors, the severity of nephropathy or presence of retinopathy, or health care utilization

Value of genetic profiling for the prediction of coronary heart disease

BACKGROUND: Advances in high-throughput genomics facilitate the identification of novel genetic susceptibility variants for coronary heart disease (CHD). This may improve CHD risk prediction. The aim of the present simulation study was to investigate to what degree CHD risk can be predicted by testing multiple genetic variants (genetic profiling). METHODS: We simulated genetic profiles for a population of 100,000 individuals with a 10-year CHD incidence of 10%. For each combination of model parameters (number of variants, genotype frequency and odds ratio [OR]), we calculated the area under the receiver operating characteristic curve (AUC) to indicate the discrimination between individuals who will and will not develop CHD. RESULTS: The AUC of genetic profiles could rise to 0.90 when 100 hypothetical variants with ORs of 1.5 and genotype frequencies of 50% were simulated. The AUC of a genetic profile consisting of 10 established variants, with ORs ranging from 1.13 to 1.42, was 0.59. When 2, 5, and 10 times as many identical variant

Short-term vascular hemodynamic responses to isometric exercise in young adults and in the elderly

Background: Vascular aging is known to induce progressive stiffening of the large elastic arteries, altering vascular hemodynamics under both rest and stress conditions. In this study, we aimed to investigate changes in vascular hemodynamics in response to isometric handgrip exercise across ages. Participants and methods: We included 62 participants, who were divided into three age categories: 20-40 (n=22), 41-60 (n=20), and 61-80 (n=20) years. Vascular hemodynamics were measured using the Mobil-o-Graph® based on the pulsatile pressure changes in the brachial artery. One-way ANOVA test was performed to analyze the changes induced by isometric handgrip exercise. Results: After isometric handgrip exercise, aortic pulse wave velocity (PWV) increased by 0.10 m/s in the youngest, 0.06 m/s in the middle-age, and 0.02 m/s in the oldest age category. Changes in PWV strongly correlated with those in central systolic blood pressure (cSBP) (r=0.878, P<0.01). After isometric exercise, the mean change of systolic blood pressure (SBP) was −1.9% in the youngest, 0.6% in the middle-aged, and 8.2% in the oldest subjects. Increasing handgrip strength was associated with an increase in SBP and cSBP (1.08 and 1.37 mmHg per 1 kg increase in handgrip strength, res