Microalbuminuria is strongly associated with NIDDM and hypertension, but not with the insulin resistance syndrome: the Hoorn study

Microalbuminuria is a strong predictor of cardiovascular disease. The aim of this study was to investigate whether microalbuminuria is part of a cluster of risk factors, the insulin resistance syndrome (IRS), or whether it is only associated with, and presumably a complication of, hypertension and non-insulin-dependent diabetes mellitus (NIDDM). An age-, sex- and glucose tolerance-stratified random sample from a 50-75 year old general population (n = 622) was investigated. The urinary albumin-to-creatinine ratio was measured in an early morning spot urine sample. Microalbuminuria was defined as an albumin-to-creatinine ratio greater than 2.0 mg/mmol. We considered, as IRS-related variables, fasting hyperinsulinaemia, insulin resistance (IR; calculated from the formula of the homeostasis model assessment), dyslipidaemia, glucose intolerance, hypertension and waist-to-hip ratio (WHR). Dyslipidaemia was defined as levels of HDL-cholesterol in the lowest and/or levels of triglyceride in the highest tertile. Fasting insulin levels, IR and WHR were divided into tertiles; the highest tertiles were compared to the lowest tertiles. Age-, sex- and glucose tolerance-adjusted analyses showed microalbuminuria to be significantly associated with hypertension, NIDDM and WHR. In multiple logistic regression analyses, microalbuminuria showed independent associations with hypertension, NIDDM and WHR, with odds ratios (ORs [95% confidence interval]) of 3.33 (1.86-5.96), 2.26 (1.14-4.48) and 2.49 (1.09-5.70), respectively. No associations were found with impaired glucose tolerance, hyperinsulinaemia, IR or dyslipidaemia. Multiple logistic regression analyses in diabetic and non-diabetic subjects separately showed that microalbuminuria was independently associated only with hypertension (ORs 4.31 and 2.69). In this Caucasian population, microalbuminuria was associated with hypertension, NIDDM and WHR and not with other variables of the IRS. It is therefore likely that microalbuminuria is a complication of hypertension and NIDDM, and not an integral part of the IRS

Endothelial LRP1 transports amyloid-β1-42 across the blood-brain barrier

According to the neurovascular hypothesis, impairment of low-density lipoprotein receptor-related protein-1 (LRP1) in brain capillaries of the blood-brain barrier (BBB) contributes to neurotoxic amyloid-beta (A beta) brain accumulation and drives Alzheimer's disease (AD) pathology. However, due to conflicting reports on the involvement of LRP1 in A beta transport and the expression of LRP1 in brain endothelium, the role of LRP1 at the BBB is uncertain. As global Lrp1 deletion in mice is lethal, appropriate models to study the function of LRP1 are lacking. Moreover, the relevance of systemic A beta clearance to AD pathology remains unclear, as no BBB-specific knockout models have been available. Here, we developed transgenic mouse strains that allow for tamoxifen-inducible deletion of Lrp1 specifically within brain endothelial cells (Slo1c1-CreER(Tz) Lrp1(fl/fl) mice) and used these mice to accurately evaluate LRP1-mediated A beta BBB clearance in vivo. Selective deletion of Lrp1 in the brain endothelium of C57BL/6 mice strongly reduced brain efflux of injected [I-125] A beta(1-42). Additionally, in the 5xFAD mouse model of AD, brain endothelial-specific Lrp1 deletion reduced plasma A beta levels and elevated soluble brain A beta, leading to aggravated spatial learning and memory deficits, thus emphasizing the importance of systemic AD elimination via the BBB. Together, our results suggest that receptor-mediated A beta BBB clearance may be a potential target for treatment and prevention of A beta brain accumulation in AD

Endothelial dysfunction contributes to renal function-associated cardiovascular mortality in a population with mild renal insufficiency: The Hoorn study

Mildly impaired renal function is associated with cardiovascular morbidity and mortality. There are indications that endothelial dysfunction and/or chronic inflammation, which play an important role in atherothrombosis, are present in early stages of renal insufficiency. This study investigated whether and to which extent endothelial dysfunction and inflammation were related to renal function and contributed to renal function-associated cardiovascular mortality in a population-based cohort (n = 613), aged 50 to 75 yr, that was followed with a median duration of 12.5 yr. During follow-up, 192 individuals died (67 of cardiovascular causes). At baseline, renal function was estimated with serum creatinine, the Cockcroft-Gault formula, and the Modification of Diet in Renal Disease equation of GFR (eGFR). Endothelial function was estimated by plasma von Willebrand factor, soluble vascular cell adhesion molecule-1, and the urinary albumin-creatinine ratio. Inflammatory activity was estimated by plasma C-reactive protein and soluble intercellular adhesion molecule-1. Renal function was mildly impaired (mean eGFR 68 ± 12 ml/min per 1.73

Large-scale parallelization of partial evaluations in evolutionary algorithms for real-world problems

The importance and potential of Gray-Box Optimization (GBO) with evolutionary algorithms is becoming increasingly clear lately, both for benchmark and real-world problems. We consider the GBO setting where partial evaluations are possible, meaning that sub-functions of the evaluation function are known and can be exploited to improve optimization efficiency. In this paper, we show that the efficiency of GBO can be greatly improved through large-scale parallelism, exploiting the fact that each evaluation function requires the calculation of a number of independent sub-functions. This is especially interesting for real-world problems where often the majority of the computational effort is spent on the evaluation function. Moreover, we show how the best parallelization technique largely depends on factors including the number of sub-functions and their required computation time, revealing that for different parts of the optimization the best parallelization technique should be selected based on these factors. As an illustration, we show how large-scale parallelization can be applied to optimization of high-dose-rate brachytherapy treatment plans for prostate cancer. We find that use of a modern Graphics Processing Unit (GPU) was the most efficient parallelization technique in all realistic scenari

Improvement of glycaemic control in type 2 diabetes: favourable changes in blood pressure, total cholesterol and triglycerides, but not in HDL cholesterol, fibrinogen, von Willebrand factor and (pro)insulin

Background: Diabetes mellitus causes a substantial increase in cardiovascular risk, which can only partly be reduced by antihyperglycaemic treatment. We were interested in whether improvement in glycaemic control is associated with improvement of other cardiovascular risk factors. Therefore, we studied among type 2 diabetic patients the association between on the one hand changes in glycaemic control and on the other hand within-subject changes of both classic cardiovascular risk factors and less conventional cardiovascular risk indicators that are typically associated with type 2 diabetes (proinsulin, insulin, fibrinogen, von Willebrand factor and the urinary albumin-creatinine ratio). Methods: The 214 type 2 diabetic patients were randomly assigned to either a strict fasting capillary glucose target level (<6.5 mmol/l) or a less strict target (<8.5 mmol/l). Duration of follow-up was two years. Since the interventions did not yield statistically significant differences between the treatment arms, we reanalysed the data focusing on within-subject changes of cardiovascular risk factors and indicators across tertiles of average HbAIC. Results: Individuals in whom HbAIC decreased had significant favourable concurrent changes in triglycerides, total cholesterol, blood pressure, and in the albumin-creatinine ratio in those who were normoalbuminuric at baseline. In contrast, these individuals had unfavourable, although not statistically significant, changes in HDL cholesterol, proinsulin, insulin, fibrinogen and von Willebrand factor. In the whole group, fibrinogen increased more than could be expected on the basis of the relationship between fibrinogen and age, namely from 3.5 ± 0.8 to 3.9 ± 0.9 g/l (p value <0.01). Conclusions: Our results suggest that improvement in glycaemia in type 2 diabetes is associated with significant favourable changes in triglycerides, total cholesterol, blood pressure and, in normoalbuminuric individuals, albumin-creatinine ratio. In contrast, it is not consistently associated with favourable changes in some cardiovascular risk indicators typically associated with diabetes, which may in part explain why antihyperglycaemic treatment does not clearly lower atherothrombotic disease risk

Cardiovascular autonomic function is associated with (micro-)albuminuria in elderly Caucasian subjects with impaired glucose tolerance or type 2 diabetes: the Hoorn Study

OBJECTIVE: To determine whether impaired cardiovascular autonomic function correlates with albuminuria in an age-, sex-, and glucose tolerance-stratified sample of an elderly (50-75 years of age) Caucasian population and to determine whether this association is independent of other determinants of albuminuria. RESEARCH DESIGN AND METHODS: We studied 536 subjects, 256 with normal glucose tolerance, 143 with impaired glucose tolerance (IGT), and 137 with type 2 diabetes. Microalbuminuria was defined as an albumin-to-creatinine ratio of > or =3.0 and 30 mg/mmol) were grouped as having albuminuria. In bivariate analyses, albuminuria was associated with age, waist-to-hip ratio, systolic and diastolic blood pressure, calculated glomerular filtration rate, and glucose tolerance status. The mean CAFS was higher in subjects with versus without albuminuria (7.5 vs. 5.9, P<0.001). Multiple logistical regression analyses revealed that the CAFS was independently associated with albuminuria in subjects with IGT or type 2 diabetes with an odds ratio (95% CI) of 1.19 (1.02-1.39) per point increase in the CAFS. CONCLUSIONS: Impaired cardiovascular autonomic function is independently associated with (and thus a possible contributor to) the presence of albuminuria in subjects with IGT or type 2 diabetes

Determinants of Citation in Epidemiological Studies on Phthalates:A Citation Analysis

Citing of previous publications is an important factor in knowledge development. Because of the great amount of publications available, only a selection of studies gets cited, for varying reasons. If the selection of citations is associated with study outcome this is called citation bias. We will study determinants of citation in a broader sense, including e.g. study design, journal impact factor or the funding source of the publication. As a case study we assess which factors drive citation in the human literature on phthalates, specifically the metabolite mono(2-ethylhexyl) phthalate (MEHP). A systematic literature search identified all relevant publications on human health effect of MEHP. Data on potential determinants of citation were extracted in duplo. Specialized software was used to create a citation network, including all potential citation pathways. Random effect logistic regression was used to assess whether these determinants influence the likelihood of citation. 112 Publications on MEHP were identified, with 5684 potential citation pathways of which 551 were actual citations. Reporting of a harmful point estimate, journal impact factor, authority of the author, a male corresponding author, research performed in North America and self-citation were positively associated with the likelihood of being cited. In the literature on MEHP, citation is mostly driven by a number of factors that are not related to study outcome. Although the identified determinants do not necessarily give strong indications of bias, it shows selective use of published literature for a variety of reasons