Associations of Cytomegalovirus Infection With All-Cause and Cardiovascular Mortality in Multiple Observational Cohort Studies of Older Adults.

BACKGROUND: Whether latent cytomegalovirus (CMV) infection in older adults has any substantial health consequences is unclear. Here, we sought associations between CMV-seropositivity and IgG titer with all-cause and cardiovascular mortality in 5 longitudinal cohorts. METHODS: Leiden Longevity Study, Prospective Study of Pravastatin in the Elderly at Risk, Longitudinal Study of Aging Danish Twins, and Leiden 85-plus Study were assessed at median (2.8-11.4 years) follow-up . Cox regression and random effects meta-analysis were used to estimate mortality risk dependent on CMV serostatus and/or IgG antibody titer, in quartiles after adjusting for confounders. RESULTS: CMV-seropositivity was seen in 47%-79% of 10 122 white community-dwelling adults aged 59-93 years. Of these, 3519 had died on follow-up (579 from cardiovascular disease). CMV seropositivity was not associated with all-cause (hazard ratio [HR], 1.05; 95% confidence interval [CI], .97-1.14) or cardiovascular mortality (HR, 0.97; 95% CI, .83-1.13). Subjects in the highest CMV IgG quartile group had increased all-cause mortality relative to CMV-seronegatives (HR, 1.16; 95% CI, 1.04-1.29) but this association lost significance after adjustment for confounders (HR, 1.13; 95% CI, .99-1.29). The lack of increased mortality risk was confirmed in subanalyses. CONCLUSIONS: CMV infection is not associated with all-cause or cardiovascular mortality in white community-dwelling older adults.

Discovery of Genetic Variation on Chromosome 5q22 Associated with Mortality in Heart Failure.

Failure of the human heart to maintain sufficient output of blood for the demands of the body, heart failure, is a common condition with high mortality even with modern therapeutic alternatives. To identify molecular determinants of mortality in patients with new-onset heart failure, we performed a meta-analysis of genome-wide association studies and follow-up genotyping in independent populations. We identified and replicated an association for a genetic variant on chromosome 5q22 with 36% increased risk of death in subjects with heart failure (rs9885413, P = 2.7x10-9). We provide evidence from reporter gene assays, computational predictions and epigenomic marks that this polymorphism increases activity of an enhancer region active in multiple human tissues. The polymorphism was further reproducibly associated with a DNA methylation signature in whole blood (P = 4.5x10-40) that also associated with allergic sensitization and expression in blood of the cytokine TSLP (P = 1.1x10-4). Knockdown of the transcription factor predicted to bind the enhancer region (NHLH1) in a human cell line (HEK293) expressing NHLH1 resulted in lower TSLP expression. In addition, we observed evidence of recent positive selection acting on the risk allele in populations of African descent. Our findings provide novel genetic leads to factors that influence mortality in patients with heart failure.

Meta-analysis of genome-wide association studies of HDL cholesterol response to statins.

BACKGROUND: In addition to lowering low density lipoprotein cholesterol (LDL-C), statin therapy also raises high density lipoprotein cholesterol (HDL-C) levels. Inter-individual variation in HDL-C response to statins may be partially explained by genetic variation. METHODS AND RESULTS: We performed a meta-analysis of genome-wide association studies (GWAS) to identify variants with an effect on statin-induced high density lipoprotein cholesterol (HDL-C) changes. The 123 most promising signals with p<1×10-4 from the 16 769 statin-treated participants in the first analysis stage were followed up in an independent group of 10 951 statin-treated individuals, providing a total sample size of 27 720 individuals. The only associations of genome-wide significance (p<5×10-8) were between minor alleles at the CETP locus and greater HDL-C response to statin treatment. CONCLUSIONS: Based on results from this study that included a relatively large sample size, we suggest that CETP may be the only detectable locus with common genetic variants that influence HDL-C response to statins substantially in individuals of European descent. Although CETP is known to be associated with HDL-C, we provide evidence that this pharmacogenetic effect is independent of its association with baseline HDL-C levels.

Subclinical Thyroid Dysfunction and Depressive Symptoms among the Elderly: A Prospective Cohort Study.

BACKGROUND: Subclinical hypothyroidism has been associated with depressive symptoms in cross-sectional studies, but prospective data and data on subclinical hyperthyroidism are scarce. METHODS: In the Leiden substudy of the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER), thyroid-stimulating hormone and free T4 levels were measured at baseline and repeated after 6 months in adults aged 70-82 years with preexisting cardiovascular disease or known cardiovascular risk factors to define persistent thyroid functional status. Main outcome measures were depressive symptoms, assessed with the Geriatric Depression Scale 15 (GDS-15) at baseline and after 3 years. All analyses were adjusted for age, gender and education. RESULTS: In 606 participants (41% women; mean age 75 years) without antidepressant medication, GDS-15 scores at baseline did not differ for participants with subclinical hypothyroidism (n = 47; GDS-15 score 1.75, 95% CI 1.29-2.20, p = 0.53) or subclinical hyperthyroidism (n = 13; GDS-15 score 1.64, 95% CI 0.78-2.51, p = 0.96) compared to euthyroid participants (n = 546; mean GDS-15 score 1.60, 95% CI 1.46-1.73). After 3 years, compared to the euthyroid participants, changes in GDS-15 scores did not differ for participants with subclinical hypothyroidism (x0394;GDS-15 score -0.03, 95% CI -0.50 to 0.44, p = 0.83), while subclinical hyperthyroidism was associated with an increase in GDS scores (x0394;GDS-15 score 1.13, 95% CI 0.32-1.93, p = 0.04). All results were similar for persistent subclinical thyroid dysfunction. CONCLUSIONS: In this largest prospective study on the association of persistent subclinical thyroid dysfunction and depression, subclinical hypothyroidism was not associated with increased depressive symptoms among older adults at high cardiovascular risk. Persistent subclinical hyperthyroidism might be associated with increased depressive symptoms, which requires confirmation in a larger prospective study.

A meta-analysis of thyroid-related traits reveals novel loci and gender-specific differences in the regulation of thyroid function.

Thyroid hormone is essential for normal metabolism and development, and overt abnormalities in thyroid function lead to common endocrine disorders affecting approximately 10% of individuals over their life span. In addition, even mild alterations in thyroid function are associated with weight changes, atrial fibrillation, osteoporosis, and psychiatric disorders. To identify novel variants underlying thyroid function, we performed a large meta-analysis of genome-wide association studies for serum levels of the highly heritable thyroid function markers TSH and FT4, in up to 26,420 and 17,520 euthyroid subjects, respectively. Here we report 26 independent associations, including several novel loci for TSH (PDE10A, VEGFA, IGFBP5, NFIA, SOX9, PRDM11, FGF7, INSR, ABO, MIR1179, NRG1, MBIP, ITPK1, SASH1, GLIS3) and FT4 (LHX3, FOXE1, AADAT, NETO1/FBXO15, LPCAT2/CAPNS2). Notably, only limited overlap was detected between TSH and FT4 associated signals, in spite of the feedback regulation of their circulating levels by the hypothalamic-pituitary-thyroid axis. Five of the reported loci (PDE8B, PDE10A, MAF/LOC440389, NETO1/FBXO15, and LPCAT2/CAPNS2) show strong gender-specific differences, which offer clues for the known sexual dimorphism in thyroid function and related pathologies. Importantly, the TSH-associated loci contribute not only to variation within the normal range, but also to TSH values outside the reference range, suggesting that they may be involved in thyroid dysfunction. Overall, our findings explain, respectively, 5.64% and 2.30% of total TSH and FT4 trait variance, and they improve the current knowledge of the regulation of hypothalamic-pituitary-thyroid axis function and the consequences of genetic variation for hypo- or hyperthyroidism.

White Matter Lesion Progression: Genome-Wide Search for Genetic Influences.

BACKGROUND AND PURPOSE: White matter lesion (WML) progression on magnetic resonance imaging is related to cognitive decline and stroke, but its determinants besides baseline WML burden are largely unknown. Here, we estimated heritability of WML progression, and sought common genetic variants associated with WML progression in elderly participants from the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium. METHODS: Heritability of WML progression was calculated in the Framingham Heart Study. The genome-wide association study included 7773 elderly participants from 10 cohorts. To assess the relative contribution of genetic factors to progression of WML, we compared in 7 cohorts risk models including demographics, vascular risk factors plus single-nucleotide polymorphisms that have been shown to be associated cross-sectionally with WML in the current and previous association studies. RESULTS: A total of 1085 subjects showed WML progression. The heritability estimate for WML progression was low at 6.5%, and no single-nucleotide polymorphisms achieved genome-wide significance (P<5×10(-8)). Four loci were suggestive (P<1×10(-5)) of an association with WML progression: 10q24.32 (rs10883817, P=1.46×10(-6)); 12q13.13 (rs4761974, P=8.71×10(-7)); 20p12.1 (rs6135309, P=3.69×10(-6)); and 4p15.31 (rs7664442, P=2.26×10(-6)). Variants that have been previously related to WML explained only 0.8% to 11.7% more of the variance in WML progression than age, vascular risk factors, and baseline WML burden. CONCLUSIONS: Common genetic factors contribute little to the progression of age-related WML in middle-aged and older adults. Future research on determinants of WML progression should focus more on environmental, lifestyle, or host-related biological factors.

Genome-wide association study for circulating tissue plasminogen activator levels and functional follow-up implicates endothelial STXBP5 and STX2.

OBJECTIVE: Tissue plasminogen activator (tPA), a serine protease, catalyzes the conversion of plasminogen to plasmin, the major enzyme responsible for endogenous fibrinolysis. In some populations, elevated plasma levels of tPA have been associated with myocardial infarction and other cardiovascular diseases. We conducted a meta-analysis of genome-wide association studies to identify novel correlates of circulating levels of tPA. APPROACH AND RESULTS: Fourteen cohort studies with tPA measures (N=26 929) contributed to the meta-analysis. Three loci were significantly associated with circulating tPA levels (P<5.0×10(-8)). The first locus is on 6q24.3, with the lead single nucleotide polymorphism (SNP; rs9399599; P=2.9×10(-14)) within STXBP5. The second locus is on 8p11.21. The lead SNP (rs3136739; P=1.3×10(-9)) is intronic to POLB and <200 kb away from the tPA encoding the gene PLAT. We identified a nonsynonymous SNP (rs2020921) in modest linkage disequilibrium with rs3136739 (r(2)=0.50) within exon 5 of PLAT (P=2.0×10(-8)). The third locus is on 12q24.33, with the lead SNP (rs7301826; P=1.0×10(-9)) within intron 7 of STX2. We further found evidence for the association of lead SNPs in STXBP5 and STX2 with expression levels of the respective transcripts. In in vitro cell studies, silencing STXBP5 decreased the release of tPA from vascular endothelial cells, whereas silencing STX2 increased the tPA release. Through an in silico lookup, we found no associations of the 3 lead SNPs with coronary artery disease or stroke. CONCLUSIONS: We identified 3 loci associated with circulating tPA levels, the PLAT region, STXBP5, and STX2. Our functional studies implicate a novel role for STXBP5 and STX2 in regulating tPA release.

A genome-wide copy number association study of osteoporotic fractures points to the 6p25.1 locus.

BACKGROUND: Osteoporosis is a systemic skeletal disease characterised by reduced bone mineral density and increased susceptibility to fracture; these traits are highly heritable. Both common and rare copy number variants (CNVs) potentially affect the function of genes and may influence disease risk. AIM: To identify CNVs associated with osteoporotic bone fracture risk. METHOD: We performed a genome-wide CNV association study in 5178 individuals from a prospective cohort in the Netherlands, including 809 osteoporotic fracture cases, and performed in silico lookups and de novo genotyping to replicate in several independent studies. RESULTS: A rare (population prevalence 0.14%, 95% CI 0.03% to 0.24%) 210 kb deletion located on chromosome 6p25.1 was associated with the risk of fracture (OR 32.58, 95% CI 3.95 to 1488.89; p = 8.69 × 10(-5)). We performed an in silico meta-analysis in four studies with CNV microarray data and the association with fracture risk was replicated (OR 3.11, 95% CI 1.01 to 8.22; p = 0.02). The prevalence of this deletion showed geographic diversity, being absent in additional samples from Australia, Canada, Poland, Iceland, Denmark, and Sweden, but present in the Netherlands (0.34%), Spain (0.33%), USA (0.23%), England (0.15%), Scotland (0.10%), and Ireland (0.06%), with insufficient evidence for association with fracture risk. CONCLUSIONS: These results suggest that deletions in the 6p25.1 locus may predispose to higher risk of fracture in a subset of populations of European origin; larger and geographically restricted studies will be needed to confirm this regional association. This is a first step towards the evaluation of the role of rare CNVs in osteoporosis.

Contrasting associations of insulin resistance with diabetes, cardiovascular disease and all-cause mortality in the elderly: PROSPER long-term follow-up.

AIMS/HYPOTHESIS: Insulin resistance is commonly proposed as a precursor to both type 2 diabetes and cardiovascular disease (CVD), yet few studies have directly compared insulin resistance with both outcomes simultaneously and determined whether associations with each outcome differ in strength or are comparable. We assessed the association of fasting insulin and HOMA-IR with incident CVD and diabetes in older people. METHODS: In the long-term follow-up of the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER) cohort, HOMA-IR measurement was available in 4,742 older people (70-82 years) without diabetes at baseline. Of these, 283 developed diabetes during the 3.2 year within-trial follow-up, while 1,943 all-cause deaths, 470 CHD deaths (identified from death records) and 590 fatal/non-fatal CVD events (identified from medical record linkage in the Scottish participants) occurred during an extended 8.6 years of total follow-up. Cause-specific Cox proportional-hazards models were fitted using multivariable models. RESULTS: Higher HOMA-IR was associated with incident diabetes: HR 4.80 (95% CI 3.14, 7.33) comparing extreme thirds after adjustment for confounders. However, HOMA-IR in the top third was not associated with all-cause mortality, CHD mortality or fatal/non-fatal CVD: HR 1.02 (95% CI 0.90, 1.17), 1.03 (0.79, 1.36) and 0.94 (0.74, 1.20), respectively. Results were similar when fasting insulin was considered as an exposure. CONCLUSIONS/INTERPRETATION: Our data support insulin resistance as a predictor of diabetes in later life but, perhaps surprisingly, suggest this pathway is of negligible importance to CVD outcomes in the elderly.

PCSK9 SNP rs11591147 is associated with low cholesterol levels but not with cognitive performance or noncardiovascular clinical events in an elderly population.

Proprotein convertase subtilisin-like/kexin type 9 (PCSK9) is a protein involved in LDL-cholesterol metabolism. The single-nucleotide polymorphism (SNP) rs11591147 has been associated with lower LDL-cholesterol and a lower risk of coronary heart disease. Because PCSK9 has high affinity to the LDL receptor, inhibiting PCSK9 is a testable therapeutic target for lipid-lowering therapy. Currently, several approaches to inhibit PCSK9 are under development, but it is unknown what the effects of those inhibitors will be on cognition or noncardiovascular clinical events. In this study, we assessed the association between rs11591147 and cognitive performance, activities of daily living (ADL), and noncardiovascular clinical events within 5,777 participants of the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER). Rs11591147 was associated with 10% to 16% lower LDL cholesterol levels (P = 3.62 × 10(-12)), but was not associated with cognitive performance, ADL, or noncardiovascular clinical events in the PROSPER study. Our findings suggest that lower cholesterol levels due to genetic variation in the PCSK9 gene are not associated with cognitive performance, functional status, or noncardiovascular clinical events.

Effect of nateglinide on the incidence of diabetes and cardiovascular events.

BACKGROUND: The ability of short-acting insulin secretagogues to reduce the risk of diabetes or cardiovascular events in people with impaired glucose tolerance is unknown. METHODS: In a double-blind, randomized clinical trial, we assigned 9306 participants with impaired glucose tolerance and either cardiovascular disease or cardiovascular risk factors to receive nateglinide (up to 60 mg three times daily) or placebo, in a 2-by-2 factorial design with valsartan or placebo, in addition to participation in a lifestyle modification program. We followed the participants for a median of 5.0 years for incident diabetes (and a median of 6.5 years for vital status). We evaluated the effect of nateglinide on the occurrence of three coprimary outcomes: the development of diabetes; a core cardiovascular outcome that was a composite of death from cardiovascular causes, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure; and an extended cardiovascular outcome that was a composite of the individual components of the core composite cardiovascular outcome, hospitalization for unstable angina, or arterial revascularization. RESULTS: After adjustment for multiple testing, nateglinide, as compared with placebo, did not significantly reduce the cumulative incidence of diabetes (36% and 34%, respectively; hazard ratio, 1.07; 95% confidence interval [CI], 1.00 to 1.15; P=0.05), the core composite cardiovascular outcome (7.9% and 8.3%, respectively; hazard ratio, 0.94, 95% CI, 0.82 to 1.09; P=0.43), or the extended composite cardiovascular outcome (14.2% and 15.2%, respectively; hazard ratio, 0.93, 95% CI, 0.83 to 1.03; P=0.16). Nateglinide did, however, increase the risk of hypoglycemia. CONCLUSIONS: Among persons with impaired glucose tolerance and established cardiovascular disease or cardiovascular risk factors, assignment to nateglinide for 5 years did not reduce the incidence of diabetes or the coprimary composite cardiovascular outcomes. (ClinicalTrials.gov number, NCT00097786.)

Effect of valsartan on the incidence of diabetes and cardiovascular events.

BACKGROUND: It is not known whether drugs that block the renin-angiotensin system reduce the risk of diabetes and cardiovascular events in patients with impaired glucose tolerance. METHODS: In this double-blind, randomized clinical trial with a 2-by-2 factorial design, we assigned 9306 patients with impaired glucose tolerance and established cardiovascular disease or cardiovascular risk factors to receive valsartan (up to 160 mg daily) or placebo (and nateglinide or placebo) in addition to lifestyle modification. We then followed the patients for a median of 5.0 years for the development of diabetes (6.5 years for vital status). We studied the effects of valsartan on the occurrence of three coprimary outcomes: the development of diabetes; an extended composite outcome of death from cardiovascular causes, nonfatal myocardial infarction, nonfatal stroke, hospitalization for heart failure, arterial revascularization, or hospitalization for unstable angina; and a core composite outcome that excluded unstable angina and revascularization. RESULTS: The cumulative incidence of diabetes was 33.1% in the valsartan group, as compared with 36.8% in the placebo group (hazard ratio in the valsartan group, 0.86; 95% confidence interval [CI], 0.80 to 0.92; P<0.001). Valsartan, as compared with placebo, did not significantly reduce the incidence of either the extended cardiovascular outcome (14.5% vs. 14.8%; hazard ratio, 0.96; 95% CI, 0.86 to 1.07; P=0.43) or the core cardiovascular outcome (8.1% vs. 8.1%; hazard ratio, 0.99; 95% CI, 0.86 to 1.14; P=0.85). CONCLUSIONS: Among patients with impaired glucose tolerance and cardiovascular disease or risk factors, the use of valsartan for 5 years, along with lifestyle modification, led to a relative reduction of 14% in the incidence of diabetes but did not reduce the rate of cardiovascular events. (ClinicalTrials.gov number, NCT00097786.)

Climate as a contributing factor in the demise of Angkor, Cambodia.

The "hydraulic city" of Angkor, the capitol of the Khmer Empire in Cambodia, experienced decades-long drought interspersed with intense monsoons in the fourteenth and fifteenth centuries that, in combination with other factors, contributed to its eventual demise. The climatic evidence comes from a seven-and-a-half century robust hydroclimate reconstruction from tropical southern Vietnamese tree rings. The Angkor droughts were of a duration and severity that would have impacted the sprawling city's water supply and agricultural productivity, while high-magnitude monsoon years damaged its water control infrastructure. Hydroclimate variability for this region is strongly and inversely correlated with tropical Pacific sea surface temperature, indicating that a warm Pacific and El Niño events induce drought at interannual and interdecadal time scales, and that low-frequency variations of tropical Pacific climate can exert significant influence over Southeast Asian climate and society.

A multifault earthquake threat for the Seattle metropolitan region revealed by mass tree mortality.

Compound earthquakes involving simultaneous ruptures along multiple faults often define a region's upper threshold of maximum magnitude. Yet, the potential for linked faulting remains poorly understood given the infrequency of these events in the historic era. Geological records provide longer perspectives, although temporal uncertainties are too broad to clearly pinpoint single multifault events. Here, we use dendrochronological dating and a cosmogenic radiation pulse to constrain the death dates of earthquake-killed trees along two adjacent fault zones near Seattle, Washington to within a 6-month period between the 923 and 924 CE growing seasons. Our narrow constraints conclusively show linked rupturing that occurred either as a single composite earthquake of estimated magnitude 7.8 or as a closely spaced double earthquake sequence with estimated magnitudes of 7.5 and 7.3. These scenarios, which are not recognized in current hazard models, increase the maximum earthquake size needed for seismic preparedness and engineering design within the Puget Sound region of >4 million residents.

Genetic predictors of fibrin D-dimer levels in healthy adults.

BACKGROUND: Fibrin fragment D-dimer, one of several peptides produced when crosslinked fibrin is degraded by plasmin, is the most widely used clinical marker of activated blood coagulation. To identity genetic loci influencing D-dimer levels, we performed the first large-scale, genome-wide association search. METHODS AND RESULTS: A genome-wide investigation of the genomic correlates of plasma D-dimer levels was conducted among 21 052 European-ancestry adults. Plasma levels of D-dimer were measured independently in each of 13 cohorts. Each study analyzed the association between ≈2.6 million genotyped and imputed variants across the 22 autosomal chromosomes and natural-log­transformed D-dimer levels using linear regression in additive genetic models adjusted for age and sex. Among all variants, 74 exceeded the genome-wide significance threshold and marked 3 regions. At 1p22, rs12029080 (P=6.4×10(-52)) was 46.0 kb upstream from F3, coagulation factor III (tissue factor). At 1q24, rs6687813 (P=2.4×10(-14)) was 79.7 kb downstream of F5, coagulation factor V. At 4q32, rs13109457 (P=2.9×10(-18)) was located between 2 fibrinogen genes: 10.4 kb downstream from FGG and 3.0 kb upstream from FGA. Variants were associated with a 0.099-, 0.096-, and 0.061-unit difference, respectively, in natural-log­transformed D-dimer and together accounted for 1.8% of the total variance. When adjusted for nonsynonymous substitutions in F5 and FGA loci known to be associated with D-dimer levels, there was no evidence of an additional association at either locus. CONCLUSIONS: Three genes were associated with fibrin D-dimer levels. Of these 3, the F3 association was the strongest, and has not been previously reported.

Statins and risk of incident diabetes: a collaborative meta-analysis of randomised statin trials.

BACKGROUND: Trials of statin therapy have had conflicting findings on the risk of development of diabetes mellitus in patients given statins. We aimed to establish by a meta-analysis of published and unpublished data whether any relation exists between statin use and development of diabetes. METHODS: We searched Medline, Embase, and the Cochrane Central Register of Controlled Trials from 1994 to 2009, for randomised controlled endpoint trials of statins. We included only trials with more than 1000 patients, with identical follow-up in both groups and duration of more than 1 year. We excluded trials of patients with organ transplants or who needed haemodialysis. We used the I(2) statistic to measure heterogeneity between trials and calculated risk estimates for incident diabetes with random-effect meta-analysis. FINDINGS: We identified 13 statin trials with 91 140 participants, of whom 4278 (2226 assigned statins and 2052 assigned control treatment) developed diabetes during a mean of 4 years. Statin therapy was associated with a 9% increased risk for incident diabetes (odds ratio [OR] 1.09; 95% CI 1.02-1.17), with little heterogeneity (I(2)=11%) between trials. Meta-regression showed that risk of development of diabetes with statins was highest in trials with older participants, but neither baseline body-mass index nor change in LDL-cholesterol concentrations accounted for residual variation in risk. Treatment of 255 (95% CI 150-852) patients with statins for 4 years resulted in one extra case of diabetes. INTERPRETATION: Statin therapy is associated with a slightly increased risk of development of diabetes, but the risk is low both in absolute terms and when compared with the reduction in coronary events. Clinical practice in patients with moderate or high cardiovascular risk or existing cardiovascular disease should not change. FUNDING: None.

Replication of LDL GWAs hits in PROSPER/PHASE as validation for future (pharmaco)genetic analyses.

BACKGROUND: The PHArmacogenetic study of Statins in the Elderly at risk (PHASE) is a genome wide association study in the PROspective Study of Pravastatin in the Elderly at risk for vascular disease (PROSPER) that investigates the genetic variation responsible for the individual variation in drug response to pravastatin. Statins lower LDL-cholesterol in general by 30%, however not in all subjects. Moreover, clinical response is highly variable and adverse effects occur in a minority of patients. In this report we first describe the rationale of the PROSPER/PHASE project and second show that the PROSPER/PHASE study can be used to study pharmacogenetics in the elderly. METHODS: The genome wide association study (GWAS) was conducted using the Illumina 660K-Quad beadchips following manufacturer's instructions. After a stringent quality control 557,192 SNPs in 5,244 subjects were available for analysis. To maximize the availability of genetic data and coverage of the genome, imputation up to 2.5 million autosomal CEPH HapMap SNPs was performed with MACH imputation software. The GWAS for LDL-cholesterol is assessed with an additive linear regression model in PROBABEL software, adjusted for age, sex, and country of origin to account for population stratification. RESULTS: Forty-two SNPs reached the GWAS significant threshold of p = 5.0e-08 in 5 genomic loci (APOE/APOC1; LDLR; FADS2/FEN1; HMGCR; PSRC1/CELSR5). The top SNP (rs445925, chromosome 19) with a p-value of p = 2.8e-30 is located within the APOC1 gene and near the APOE gene. The second top SNP (rs6511720, chromosome 19) with a p-value of p = 5.22e-15 is located within the LDLR gene. All 5 genomic loci were previously associated with LDL-cholesterol levels, no novel loci were identified. Replication in WOSCOPS and CARE confirmed our results. CONCLUSION: With the GWAS in the PROSPER/PHASE study we confirm the previously found genetic associations with LDL-cholesterol levels. With this proof-of-principle study we show that the PROSPER/PHASE study can be used to investigate genetic associations in a similar way to population based studies. The next step of the PROSPER/PHASE study is to identify the genetic variation responsible for the variation in LDL-cholesterol lowering in response to statin treatment in collaboration with other large trials.

Contrasting physiological traits of shade tolerance in Pinus and Podocarpaceae native to a tropical Vietnamese forest: insight from an aberrant flat-leaved pine.

The absence of pines from tropical forests is a puzzling biogeographical oddity potentially explained by traits of shade intolerance. Pinus krempfii (Lecomte), a flat-leaved pine endemic to the Central Highlands of Vietnam, provides a notable exception as it seems to compete successfully with shade-tolerant tropical species. Here, we test the hypothesis that successful conifer performance at the juvenile stage depends on physiological traits of shade tolerance by comparing the physiological characteristics of P. krempfii to coexisting species from two taxa: the genus Pinus, and a relatively abundant and shade-tolerant conifer family found in pantropical forests, the Podocarpaceae. We examined leaf photosynthetic, respiratory and biochemical traits. Additionally, we compiled attainable maximum photosynthesis, maximum RuBP carboxylation (Vcmax) and maximum electron transport (Jmax) values for Pinus and Podocarpaceae species from the literature. In our literature compilation, P. krempfii was intermediate between Pinus and Podocarpaceae in its maximum photosynthesis and its Vcmax. Pinus exhibited a higher Vcmax than Podocarpaceae, resulting in a less steep slope in the linear relationship between Jmax and Vcmax. These results suggest that Pinus may be more shade intolerant than Podocarpaceae, with P. krempfii falling between the two taxa. However, in contrast, Vietnamese conifers' leaf mass per areas and biochemical traits did not highlight the same intermediate nature of P. krempfii. Furthermore, regardless of leaf morphology or family assignation, all species demonstrated a common and extremely high carbon gain efficiency. Overall, our findings highlight the importance of shade-tolerant photosynthetic traits for conifer survival in tropical forests. However, they also demonstrate a diversity of shade tolerance strategies, all of which lead to the persistence of Vietnamese juvenile conifers in low-light tropical understories.

Cholesterol absorption and synthesis markers in individuals with and without a CHD event during pravastatin therapy: insights from the PROSPER trial.

Cholesterol homeostasis, defined as the balance between absorption and synthesis, influences circulating cholesterol concentrations and subsequent coronary heart disease (CHD) risk. Statin therapy targets the rate-limiting enzyme in cholesterol biosynthesis and is efficacious in lowering CHD events and mortality. Nonetheless, CHD events still occur in some treated patients. To address differences in outcome during pravastatin therapy (40 mg/day), plasma markers of cholesterol synthesis (desmosterol, lathosterol) and fractional cholesterol absorption (campesterol, sitosterol) were measured, baseline and on treatment, in the Prospective Study of Pravastatin in the Elderly at Risk trial participants with (cases, n = 223) and without (controls, n = 257) a CHD event. Pravastatin therapy decreased plasma LDL-cholesterol and triglycerides and increased HDL-cholesterol concentrations to a similar extent in cases and controls. Decreased concentrations of the cholesterol synthesis markers desmosterol (-12% and -11%) and lathosterol (-50% and -56%) and increased concentrations of the cholesterol absorption markers campesterol (48% and 51%) and sitosterol (25% and 26%) were observed on treatment, but the magnitude of change was similar between cases and controls. These data suggest that decreases in cholesterol synthesis in response to pravastatin treatment were accompanied by modest compensatory increases in fractional cholesterol absorption. The magnitude of these alterations were similar between cases and controls and do not explain differences in outcomes with pravastatin treatment.

Genetic variation at the NPC1L1 gene locus, plasma lipoproteins, and heart disease risk in the elderly.

Niemann-Pick C1-like 1 protein (NPC1L1) plays a critical role in intestinal cholesterol absorption. Our objective was to examine whether five variants (-133A>G, -18A>C, L272L, V1296V, and U3_28650A>G) at the NPC1L1 gene have effects on lipid levels, prevalence, and incidence of coronary heart disease (CHD) and lipid-lowering response to pravastatin. We studied 5,804 elderly participants from the PROSPER study, who were randomized to prava-statin 40 mg/day or placebo and were followed on average for 3.2 years. In the adjusted gender-pooled analyses, homozygous carriers of the minor alleles at four NPC1L1 sites (-18A>C, L272L, V1296V, and U3_28650A>G, minor allele frequencies 0.15-0.33) had 2-8% higher LDL-cholesterol (LDL-C) levels at baseline than homozygous carriers of the common alleles (P < 0.05). Homozygotes for the rare alleles also had a significant increase in the risk of CHD events on trial (range of hazard ratios 1.50-1.67; P < 0.02), regardless of the treatment regimen. The -133 A>G polymorphism and not other variants was associated with 6 month LDL-C lowering (P = 0.02). Our data indicate that variation in the NPC1L1 gene is associated with plasma total and LDL-C levels and CHD risk.