Long-term neurologic and cognitive outcome and quality of life in adults after pneumococcal meningitis.

OBJECTIVES: To perform a cross-sectional cohort study on long-term neurologic, cognitive and quality-of-life outcome in adults surviving pneumococcal meningitis. METHODS: Adult survivors of community-acquired pneumococcal meningitis from a Dutch nationwide prospective cohort study were evaluated 1 to 5 years after acute illness. The control group consisted of partners or proxies of patients. Neurologic examination was performed and cognitive domains were tested with the Vienna Test System Cognitive Basic Assessment Test set (VTS COGBAT). The Research and Development (RAND)-36 and adapted Cognitive and Emotional Consequences of Stroke (CLCE)-24 questionnaires assessed perceived cognitive functioning and quality of life. Differences between group scores were tested with multivariate analyses of variance. RESULTS: A total of 80 pneumococcal meningitis patients and 69 controls were evaluated. After a median of 2 years (interquartile range, 2-3) after acute illness, 27 (34%) of 79 patients had persistent neurologic sequelae, most commonly hearing loss (21/79, 27%). On overall neuropsychologic evaluation, patients performed worse than the controls (MANCOVA; p 0.008), with alertness (z score -0.33, p 0.011) and cognitive flexibility (z score -0.33, p 0.027) as the most affected domains. Cognitive impairment was present in 11 (14%) of 79 patients. CLCE-24 questionnaires revealed cognitive impairment on all domains, most commonly for cognitive speed (53/75, 71%), attention (45/75, 60%) and memory (46/75, 61%). Patients had lower quality-of-life scores than controls (item physical functioning, (median) patients vs. controls, 80 vs. 95, p < 0.001; social functioning, (median) 81 vs. 100, p 0.003; perceived health, (mean) 59 vs. 70, p 0.005), which correlated with cognitive complaints (R = 0.66, p < 0.001). CONCLUSIONS: Adults after pneumococcal meningitis are at high risk of long-term neurologic and neuropsychologic deficits impairing daily life activities and quality of life.

Poly(trimethylene carbonate) and poly(D,L-lactic acid) modify human dendritic cell responses to staphylococci but do not affect Th1 and Th2 cell development.

Biomaterial-associated infections (BAIs) are frequent complications in the use of medical devices (biomaterials) correlated with considerable patient discomfort and high treatment costs. The presence of a biomaterial in the host causes derangement of local immune responses increasing susceptibility to infection. Dendritic cells (DCs) have an important role in directing the nature of immune responses by activating and controlling CD4+ T helper (Th) cell responses. To assess the immunomodulatory effect of the combined presence of biomaterials and Staphylococcus aureus (S. aureus) or Staphylococcus epidermidis (S. epidermidis), DC-mediated T cell proliferation and Th1/Th2 cell development were measured using an in vitro human cell system. Poly(trimethylene carbonate) (PTMC) and poly(D,L-lactic acid) (PDLLA) modified the production of the DC pro-inflammatory cytokines TNF-α, IL-6 and IL-23 in response to S. aureus and S. epidermidis. However, this modified cytokine production did not cause differences in Th1/Th2 cell polarisation, showing a Th1 cell predominance. In the absence of staphylococci, neither of the biomaterials induced DC-mediated T cell proliferation or Th1/Th2 cell polarisation. Moreover, either in the absence or presence of the biomaterials, S. aureus was a more potent inducer of DC cytokine secretion, T cell proliferation and Th1 cell development than S. epidermidis. In conclusion, although PTMC and PDLLA modulated DC cytokine responses to staphylococci, this did not alter the resulting Th cell development. This result suggested that, in this human cell model, Th1/Th2 cell responses were mainly determined by the species of bacteria and that PTMC or PDLLA did not detectably influence these responses.

Impact of an evidence-based guideline on the management of community-acquired bacterial meningitis: a prospective cohort study.

OBJECTIVES: To study the impact of an evidence-based guideline on the management of community-acquired bacterial meningitis. METHODS: We performed an interrupted time series analysis in a prospective nationwide cohort study from 2006 to 2015. The guideline stresses the importance of cranial imaging before lumbar puncture (LP) in selected patients based on clinical criteria, and early treatment with amoxicillin and a third-generation cephalosporin for adults with suspected community-acquired bacterial meningitis. The guideline was published in April 2013. RESULTS: We included 1326 episodes before and 210 episodes after guideline introduction. Cranial imaging was performed before LP in 497 (84%) of 591 episodes with clinical criteria warranting computed tomography (CT). The guideline did not improve this (increase of 2%; 95% confidence interval (CI), -15 to 19). Without these criteria, imaging before LP occurred in 606 (67%) of 900 episodes, also without effect of the guideline (increase of 1%; 95% CI, -25 to 28). The estimate of effect of the guideline for treatment with the recommended antibiotic regimen was an increase of 19.5% (95% CI, 13.5 to 25.5), and there was a trend towards more frequent initiation of treatment before CT. There was no association between delay in antibiotic treatment due to imaging before LP and unfavourable outcome (odds ratio, 1.14; 95% CI 0.86 to 1.52). CONCLUSIONS: Cranial imaging is performed before LP in the majority of patients with bacterial meningitis, irrespective of guideline indications. The guideline introduction was associated with a trend towards early initiation of treatment before imaging and with increased adherence to antibiotic policy.

Clonidine increases bone resorption in humans.

SUMMARY: Inhibition of sympathetic signaling to bone reduces bone resorption in rodents. In contrast, we show that pharmacological reduction of the sympathetic tone increases bone resorption in humans in vivo. This effect does not appear to be mediated via a direct pharmacological effect on the osteoclast. INTRODUCTION: Inhibition of sympathetic signaling to bone reduces bone resorption in rodents. It is uncertain whether a similar role for the sympathetic nervous system exists in humans. The sympathetic tone can be reduced by clonidine, which acts via alpha-2-adrenergic receptors in the brainstem. Our objective was to determine the effect of clonidine on bone turnover in humans. METHODS: The acute effect of a single oral dose of 0.3 mg clonidine on serum bone turnover markers (C-terminal cross-linking telopeptides of collagen type I (CTx), a marker for bone resorption, and procollagen type 1 N propeptide (P1NP), a marker for bone formation) was determined in a randomized crossover design in 12 healthy volunteers, aged 18-70 years. In addition, we assessed the effect of clonidine on the number of tartrate-resistant acid phosphatase-positive multinucleated cells (TRAcP(+) MNCs) and bone resorption. RESULTS: CTx concentrations increased after clonidine treatment compared to the control condition (p = 0.035). P1NP concentrations were not affected by clonidine (p = 0.520). In vitro, clonidine had no effect on the number of TRAcP(+) MNCs (p = 0.513) or on bone resorption (p = 0.996). CONCLUSIONS: We demonstrated that clonidine increases bone resorption in humans in vivo. This effect does not appear to be mediated via a direct effect on the osteoclast.

Changes in microbiota during experimental human Rhinovirus infection.

BACKGROUND: Human Rhinovirus (HRV) is responsible for the majority of common colds and is frequently accompanied by secondary bacterial infections through poorly understood mechanisms. We investigated the effects of experimental human HRV serotype 16 infection on the upper respiratory tract microbiota. METHODS: Six healthy volunteers were infected with HRV16. We performed 16S ribosomal RNA-targeted pyrosequencing on throat swabs taken prior, during and after infection. We compared overall community diversity, phylogenetic structure of the ecosystem and relative abundances of the different bacteria between time points. RESULTS: During acute infection strong trends towards increases in the relative abundances of Haemophilus parainfluenzae and Neisseria subflava were observed, as well as a weaker trend towards increases of Staphylococcus aureus. No major differences were observed between day-1 and day 60, whereas differences between subjects were very high. CONCLUSIONS: HRV16 infection is associated with the increase of three genera known to be associated with secondary infections following HRV infections. The observed changes of upper respiratory tract microbiota could help explain why HRV infection predisposes to bacterial otitis media, sinusitis and pneumonia.

Study on the protective effect of the KIR3DL1 gene in ankylosing spondylitis.

OBJECTIVE: Ankylosing spondylitis (AS) is an autoimmune disease that mainly affects the sacroiliac joints and the spine of the lower back. The disease is strongly associated with HLA-B27. Additional genes, single-nucleotide polymorphisms, and molecular components have been identified to be associated with AS, but the exact mechanism that drives disease development remains poorly understood. The killer cell immunoglobulin-like receptors (KIRs) are regulators of cytotoxicity of natural killer cells and T cell subsets and may be relevant in binding to HLA-B27 and the development of AS. We undertook this study to identify possible associations of KIR genotype with susceptibility to AS and disease characteristics including the presence of the HLA-B27 allele, disease severity, and uveitis. METHODS: We performed complete genotyping of the KIR locus in 303 Caucasian AS patients, 119 randomly selected healthy Caucasian controls, and 50 HLA-B27-positive healthy Caucasian controls by multiplex ligation-dependent probe amplification assay for detection of gene presence and copy number. RESULTS: We did not observe a significant association of any specific KIR gene or haplotype with susceptibility to AS or any other clinical manifestation. Disease severity, as measured by fulfilling the criteria for treatment with tumor necrosis factor blocking therapy, was linked to a lower number of genes for the functional variant of KIR3DL1 (P = 0.007). CONCLUSION: Our exploratory study indicates that KIR genes are not a major risk factor for susceptibility to AS. However, the data do suggest a role for KIRs in progression of the disease, whereby KIR3DL1 has a protective effect against the more severe manifestations of AS.

Association of polymorphisms in the beta-2 adrenergic receptor gene with fracture risk and bone mineral density.

UNLABELLED: Signaling through the beta-2 adrenergic receptor (B2AR) on the osteoblast influences bone remodeling in rodents. In the B2AR gene, three polymorphisms influence receptor function. We show that these polymorphisms are not associated with fracture risk or bone mineral density in the UCP, Rotterdam Study, and GEFOS cohorts. INTRODUCTION: Signaling through the beta-2 adrenergic receptor (B2AR) on the osteoblast influences bone remodeling in rodents. In the B2AR gene, three polymorphisms are known to influence receptor function in vitro and in vivo (rs1042713, rs1042714, and rs1800888). We examined the role of these polymorphisms in the B2AR gene on human bone metabolism. METHODS: We performed nested case-control studies to determine the association of these polymorphisms with fracture risk in the Utrecht Cardiovascular Pharmacogenetics (UCP) cohort and in three cohorts of the Rotterdam Study. We also determined the association of these polymorphisms with bone mineral density (BMD) in the GEFOS Consortium. UCP contains drug-dispensing histories from community pharmacies linked to national registrations of hospital discharges in the Netherlands. The Rotterdam Study is a prospective cohort study investigating demographics and risk factors of chronic diseases. GEFOS is a large international collaboration studying the genetics of osteoporosis. Fractures were defined by ICD-9 codes 800-829 in the UCP cohort (158 cases and 2617 unmatched controls) and by regular X-ray examinations, general practitioner, and hospital records in the Rotterdam Study (2209 cases and 8559 unmatched controls). BMD was measured at the femoral neck and lumbar spine using dual-energy X-ray absorptiometry in GEFOS (N = 32,961). RESULTS: Meta-analysis of the two nested case-control studies showed pooled odds ratios of 0.98 (0.91-1.05, p = 0.52), 1.04 (0.97-1.12, p = 0.28), and 1.16 (0.83-1.62, p = 0.38) for the associations between rs1042713, rs1042714, and rs1800888 per minor allele and fractures, respectively. There were no significant associations of the polymorphisms and BMD in GEFOS. CONCLUSION: In conclusion, polymorphisms in the beta-2 adrenergic receptor gene are not associated with fracture risk or BMD.

Platelet and endothelial cell P-selectin are required for host defense against Klebsiella pneumoniae-induced pneumosepsis.

BACKGROUND: Sepsis is associated with activation of platelets and endothelial cells accompanied by enhanced P-selectin surface expression. Both platelet- and endothelial P-selectin have been associated with leukocyte recruitment and induction of inflammatory alterations. Klebsiella (K.) pneumoniae is a common human sepsis pathogen, particularly in the context of pneumonia. METHODS: Wild-type (WT) and P-selectin-deficient (Selp(-/-) ) mice or bone marrow chimeric mice were infected with K. pneumoniae via the airways to induce pneumosepsis. Mice were sacrificed during early (12 h after infection) or late-stage (44 h) sepsis for analyses, or followed in a survival study. RESULTS: Selp(-/-) mice displayed 10-1000-fold higher bacterial burdens in the lungs, blood and distant organs during late-stage sepsis. P-selectin deficiency did not influence leukocyte recruitment to the lungs, but was associated with decreased platelet-monocyte complexes and increased cytokine release. Bone marrow transfer studies revealed a role for both platelet and endothelial cell P-selectin as mice deficient in platelet or endothelial cell P-selectin displayed an intermediate phenotype in bacterial loads and survival compared with full wild-type or full knockout control mice. CONCLUSION: Both platelet and endothelial cell P-selectin contribute to host defense during Klebsiella pneumosepsis.

The effects of beta-2 adrenergic agonist and antagonist on human bone metabolism: a randomized controlled trial.

PURPOSE: Genetic knockout or pharmacological inhibition of the beta-2 adrenergic receptor (B2AR) increased bone mass, whereas stimulation decreased bone mass in rodents. In humans, observational studies support sympathetic nervous system regulation of bone metabolism, but intervention studies are lacking. We aimed to determine the effects of a selective beta-2 adrenergic agonist and non-selective antagonist on human bone metabolism. METHODS: 32 healthy postmenopausal women were included in a randomized controlled trial conducted in the Academic Medical Center Amsterdam. Participants were randomized to receive treatment with 17-ß estradiol 2mg/day; 17-ß estradiol 2mg/day and terbutaline 5mg/day (selective B2AR agonist); propranolol 80mg/day (non-selective B-AR antagonist); or no treatment during 12weeks. Main outcome measure was the change in serum concentrations of procollagen type I N propeptide (P1NP) and C-terminal crosslinking telopeptides of collagen type I (CTx) as markers of bone formation and resorption after 12weeks compared between the treatment groups. Data were analyzed with mixed model analysis. RESULTS: 17-ß estradiol decreased bone turnover compared to control (P1NP p<0.001, CTx p=0.003), but terbutaline combined with 17-ß estradiol failed to increase bone turnover compared to 17-ß estradiol alone (P1NP p=0.135, CTx p=0.406). Propranolol did not affect bone turnover compared to control (P1NP p=0.709, CTx p=0.981). CONCLUSION: Selective beta-2 adrenergic agonists and non-selective beta-antagonists do not affect human bone turnover although we cannot exclude small changes below the detection limit of this study.

The Fc gamma receptor IIa R131H polymorphism is associated with inhibitor development in severe hemophilia A.

BACKGROUND: The development of factor (F) VIII neutralizing alloantibodies (inhibitors) is a major complication of treatment with FVIII concentrates in hemophilia A and the etiology is still poorly understood. The low-affinity Fc gamma receptors (FcγR), which are expressed on immune cells, provide an important link between cellular and humoral immunity by interacting with IgG subtypes. Genetic variations of the genes encoding FcγRs (FCGR genes) have been associated with susceptibility to infectious and autoimmune diseases. OBJECTIVES: The aim of this study was to investigate the association between genetic variation of FCGR and inhibitor development in severe hemophilia A. PATIENTS/METHODS: In this case-control study samples of 85 severe hemophilia A patients (siblings from 44 families) were included. Single nucleotide polymorphisms and copy number variation of the FCGR2 and FCGR3 gene cluster were studied in an FCGR-specific multiplex ligation-dependent probe amplification assay. Frequencies were compared in a generalized estimating equation regression model. RESULTS: Thirty-six patients (42%) had a positive history of inhibitor development. The polymorphism 131R > H in the FCGR2A gene was associated with an increased risk of inhibitor development (odds ratio [OR] per H-allele, 1.8; 95% confidence interval [CI], 1.1-2.9). This association persisted in 29 patients with high titer inhibitors (OR per H-allele, 1.9; 95% CI, 1.2-3.2) and in 44 patients with the F8 intron 22 inversion (OR per H-allele, 2.6; 95% CI, 1.1-6.6). CONCLUSIONS: Hemophilia A patients with the HH genotype of the FCGR2A polymorphism 131R > H have a more than 3-fold increased risk of inhibitor development compared with patients with the RR genotype.

Polymorphisms in the melatonin receptor 1B gene and the risk of delirium.

BACKGROUND/AIMS: A disturbed sleep-wake rhythm cycle can be seen in delirium and as melatonin regulates this cycle via melatonin receptors, genetic variations in these receptors may contribute to susceptibility to delirium. The purpose of this study was to investigate whether genetic variants in the melatonin receptor 1B (MTNR1B) gene are associated with delirium. METHODS: Elderly medical and hip surgery patients were included in the study. Five single-nucleotide polymorphisms (SNPs) were determined in the MTNR1B gene, i.e. rs18030962, rs3781638, rs10830963, rs156244 and rs4753426. RESULTS: In total, 53% of 171 hip fracture patients and 33% of 699 medical patients were diagnosed with delirium. None of the polymorphisms were found to be associated with the occurrence of delirium. CONCLUSION: Future research could focus on sequencing this gene to look for other functional SNPs in relation to delirium.

High levels of protein C are determined by PROCR haplotype 3.

BACKGROUND: Genetic determinants of plasma levels of protein C (PC) are poorly understood. Recently, we identified a locus on chromosome 20 determining high PC levels in a large Dutch pedigree with unexplained thrombophilia. Candidate genes in the LOD-1 support interval included FOXA2, THBD and PROCR. OBJECTIVES: To examine these candidate genes and their influence on plasma levels of PC. PATIENTS/METHODS: Exons, promoter and 3'UTR of the candidate genes were sequenced in 12 family members with normal to high PC levels. Four haplotypes of PROCR, two SNPs in the neighboring gene EDEM2 and critical SNPs encountered during resequencing were genotyped in the family and in a large group of healthy individuals (the Leiden Thrombophilia Study (LETS) controls). Soluble endothelial protein C receptor (sEPCR) and soluble thrombomodulin (sTM) plasma levels were measured in the family. RESULTS: PROCR haplotype 3 (H3) and FOXA2 rs1055080 were associated with PC levels in the family but only PROCR H3 was also associated with plasma levels in the healthy individuals. Carriers of both variants had higher PC levels than carriers of only PROCR H3 in the family but not in healthy individuals, suggesting that a second determinant is present. EDEM2 SNPs were associated with PC levels, but their effect was small. PC and sEPCR levels were associated in both studies. sTM was not associated with variations of THBD or PC levels. CONCLUSIONS: Chromosome 20 harbors genetic determinants of PC and sEPCR levels and the analysis of candidate genes suggests that the PROCR locus is responsible.

Efficient ways exist to obtain the optimal sample size in clinical trials in rare diseases.

OBJECTIVE: Recruitment of pediatric patients in randomized clinical trials is hampered by the rarity of many conditions and by ethical constraints. The objective of this paper is to give an overview of design options to obtain a statistically valid result while including a minimum number of subjects. STUDY DESIGN AND SETTING: Overview and discussion of several approaches to conduct valid randomized clinical trials in rare diseases and vulnerable populations. RESULTS: Sequential designs have been developed as efficient ways to evaluate accumulating information from a clinical trial, thereby reducing the average size of trials. Different sequential procedures exist, including group sequential designs, boundaries designs, and adaptive designs. The sample size attained at the end of the trial is unknown at the start. The sample size for a given set of alpha, beta, and effect size may turn out to be larger than with a classical fixed sample size approach. Simulations have shown that on average, sample sizes are smaller. CONCLUSION: There are several possibilities to optimize the number of subjects in a clinical trial. The rarity of many disorders in children and the ethical requirements in this patient population should not obstruct the performance of well-designed research to support clinical decision making.

Effect of acute hyperglycaemia and/or hyperinsulinaemia on proinflammatory gene expression, cytokine production and neutrophil function in humans.

AIMS: Type 2 diabetes is frequently associated with infectious complications. Swift activation of leucocytes is important for an adequate immune response. We determined the selective effects of hyperglycaemia and hyperinsulinaemia on lipopolysaccharide (LPS)-induced proinflammatory gene expression and cytokine production in leucocytes and on neutrophil functions. METHODS: Six healthy humans were studied on four occasions for 6 h during: (i) lower insulinaemic euglycaemic clamp, (ii) lower insulinaemic hyperglycaemic clamp, (iii) hyperinsulinaemic euglycaemic clamp, and (iv) hyperinsulinaemic hyperglycaemic clamp. Target levels of plasma glucose were 12.0 mmol/l (hyperglycaemic clamps) or 5.0 mmol/l (euglycaemic clamps). Target plasma insulin levels were 400 pmol/l (hyperinsulinaemic clamps) or 100 pmol/l (lower insulinaemic clamps). RESULTS: Hyperglycaemia reduced LPS-induced mRNA expression of nuclear factor of kappa light polypeptide gene enhancer in B cells inhibitor alpha (NFKBIA), interleukin-1 alpha (IL1A) and chemokine (C-C motif) ligand 3 (CCL3), whereas during hyperinsulinaemia enhanced mRNA levels occurred in six out of eight measured inflammation-related genes, irrespective of plasma glucose levels. Combined hyperglycaemia and hyperinsulinaemia led to enhanced IL1A, interleukin-1 beta (IL1B) and CCL3 mRNA levels upon LPS stimulation. Neither hyperglycaemia nor hyperinsulinaemia altered cytokine protein production, neutrophil migration, phagocytic capacity or oxidative burst activity. CONCLUSIONS: These results suggest that short-term hyperglycaemia and hyperinsulinaemia influence the expression of several inflammatory genes in an opposite direction, that the acute effects of hyperinsulinaemia on inflammatory mRNA levels may be stronger than those of hyperglycaemia, and that the effects of insulin, in particular, may be relevant in the concurrent presence of hyperglycaemia.

Family history and inherited thrombophilia.

BACKGROUND: It is a common belief that patients with venous thrombosis and a positive family history for venous thromboembolism (VTE) have an increased likelihood of having an inherited thrombophilic defect. METHODS: We analyzed the relation between family history, qualified with three different methods, and thrombophilic status in 314 patients with proven VTE. A positive family history (one or more first-degree relatives with VTE) and a strongly positive family history (two or more first-degree relatives with VTE). In 118 of the patients a third, more precise method was analyzed: the family history score, which compares the observed and the expected number of first-degree family members with VTE. RESULTS: Patients with a positive or strongly positive family history had a slightly increased chance of having inherited thrombophilia compared to those without a positive family history. For positive family history this was 42% vs. negative 32%, likelihood ratio 1.3 (95% confidence interval; CI 0.9-2.1) and for strongly positive family history this was 46% vs. negative 34%, likelihood ratio 1.6 (95% CI 0.7-3.3). The family history score correlated with the chance of having inherited thrombophilia [OR 1.23 per score point (95% CI 1.01-1.48)]. However, even with this method the chance of having inherited thrombophilia is lower than 50% in 97% of the cases. CONCLUSIONS: Family history of VTE is not a precise tool in clinical practice to identify patients with inherited thrombophilia among patients with VTE. The family history score is more precise, but probably only useful for research purposes and not for daily practice.

Multiple imputation of missing genotype data for unrelated individuals.

The objective of this study was to investigate the performance of multiple imputation of missing genotype data for unrelated individuals using the polytomous logistic regression model, focusing on different missingness mechanisms, percentages of missing data, and imputation models. A complete dataset of 581 individuals, each analysed for eight biallelic polymorphisms and the quantitative phenotype HDL-C, was used. From this dataset one hundred replicates with missing data were created, in different ways for different scenarios. The performance was assessed by comparing the mean bias in parameter estimates, the root mean squared standard errors, and the genotype-imputation error rates. Overall, the mean bias was small in all scenarios, and in most scenarios the mean did not differ significantly from 'no bias'. Including polymorphisms that are highly correlated in the imputation model reduced the genotype-imputation error rate and increased precision of the parameter estimates. The method works well for data that are missing completely at random, and for data that are missing at random. In conclusion, our results indicate that multiple imputation with the polytomous logistic regression model can be used for association studies to deal with the problem of missing genotype data, when attention is paid to the imputation model and the percentage of missing data.

Common variants of multiple genes that control reverse cholesterol transport together explain only a minor part of the variation of HDL cholesterol levels.

It is assumed that the combined effects of multiple common genetic variants explain a large part of variation of high-density lipoprotein cholesterol (HDL-C) plasma levels, but little evidence exists to corroborate this assumption. It was our objective to study the contribution of multiple common genetic variants of HDL-C-related genes to variation of HDL-C plasma levels. A well-characterized cohort of 546 Caucasian men with documented coronary artery disease was genotyped for common functional variants in genes that control reverse cholesterol transport: ATP-binding cassette transporter A1, apolipoprotein A-I and apolipoprotein-E, cholesteryl ester transfer protein, hepatic lipase, lecithin : cholesterol-acyl transferase, lipoprotein lipase, and scavenger receptor class B type 1. Multivariate linear regression showed that these variants, in conjunction, explain 12.4% (95% confidence interval: 6.9-17.9%) of variation in HDL-C plasma levels. When the covariates smoking and body mass index were taken into account, the explained variation increased to 15.3% (9.4-21.2%), and when 10 two-way interactions were incorporated, this percentage rose to 25.2% (18.9-31.5%). This study supports the hypothesis that multiple, mildly penetrant, but highly prevalent genetic variants explain part of the variation of HDL-C plasma levels, albeit to a very modest extent. Multiple environmental and genetic influences on HDL-C plasma levels still have to be elucidated.

Glucose tolerance at age 58 and the decline of glucose tolerance in comparison with age 50 in people prenatally exposed to the Dutch famine.

AIMS/HYPOTHESIS: People who were small at birth have an increased risk of type 2 diabetes in later life. People who were in utero during the Dutch famine had decreased glucose tolerance and raised insulin concentrations at age 50. We aimed to evaluate whether prenatal famine exposure leads to more rapid progression of impaired glucose/insulin homeostasis with increasing age. METHODS: We performed an OGTT in 702 men and women at age 50 and in 699 men and women at age 58, all born as term singletons immediately before, during or after the 1944-1945 Dutch famine. RESULTS: People who had been exposed to famine in utero had significantly higher 120-min glucose concentrations at age 58 compared with people who had not been exposed to famine (difference=0.4 mmol/l, 95% CI 0.1 to 0.7, adjusted for sex and BMI). Glucose tolerance deteriorated between the age of 50 and 58. The unadjusted 120-min glucose concentrations rose by 0.2 mmol/l (95% CI 0.0 to 0.4), while 120-min insulin concentrations had increased by 64 pmol/l (95% CI 48 to 82). There were no differences in the rates of glucose and insulin level increase between the famine-exposed group and the unexposed group (p=0.28 for the difference in increase in glucose concentrations and p=0.09 for insulin concentrations). CONCLUSIONS/INTERPRETATION: Although we confirmed that undernutrition during gestation is linked to decreased glucose tolerance, the effect does not seem to become more pronounced at age 58 as compared with age 50.

The contribution of classical risk factors to cardiovascular disease in familial hypercholesterolaemia: data in 2400 patients.

OBJECTIVE: To determine the contribution of classical risk factors to the development of cardiovascular disease (CVD) in patients with heterozygous familial hypercholesterolaemia (FH). DESIGN: A retrospective, multi-centre, cohort study. Extensive data were collected by scrutinizing medical records and the use of questionnaires. Multivariate Cox regression was used to study the relationship between potential risk factors and the occurrence of CVD. SETTING AND SUBJECTS: We included 2400 FH patients from 27 Dutch lipid clinics. The diagnosis of FH was based upon the presence of a low-density lipoprotein receptor mutation or upon strict clinical criteria. MAIN OUTCOME MEASURES: Cardiovascular mortality and CVD. RESULTS: During 112.943 person-years, 782 (32.6%) patients had had at least one cardiovascular event. Male gender (RR 2.82, 95% CI 2.37-3.36), smoking (RR 1.67, 95% CI 1.40-1.99), hypertension (RR 1.36, 95% CI 1.06-1.75), diabetes mellitus (RR 2.19, 95% CI 1.36-3.54), low HDL-C (RR 1.37, 95% CI 1.15-1.63) and elevated lipoprotein(a) levels (RR 1.50, 95% CI 1.20-1.79) proved to be independent CVD risk factors. These six risk factors explained 18.7% of the variation in the occurrence of CVD. CONCLUSIONS: Male gender, smoking, hypertension, diabetes mellitus, HDL cholesterol and lipoprotein(a) levels proved to be important risk factors for CVD in FH patients. In addition to the routine institution of statin therapy, controlling these factors needs special attention in the management of this disorder.