@article {1142, title = {Prediction of incident stroke events based on retinal vessel caliber: a systematic review and individual-participant meta-analysis.}, journal = {Am J Epidemiol}, volume = {170}, year = {2009}, month = {2009 Dec 01}, pages = {1323-32}, abstract = {

The caliber of the retinal vessels has been shown to be associated with stroke events. However, the consistency and magnitude of association, and the changes in predicted risk independent of traditional risk factors, are unclear. To determine the association between retinal vessel caliber and the risk of stroke events, the investigators combined individual data from 20,798 people, who were free of stroke at baseline, in 6 cohort studies identified from a search of the Medline (National Library of Medicine, Bethesda, Maryland) and EMBASE (Elsevier B.V., Amsterdam, the Netherlands) databases. During follow-up of 5-12 years, 945 (4.5\%) incident stroke events were recorded. Wider retinal venular caliber predicted stroke (pooled hazard ratio = 1.15, 95\% confidence interval: 1.05, 1.25 per 20-micron increase in caliber), but the caliber of retinal arterioles was not associated with stroke (pooled hazard ratio = 1.00, 95\% confidence interval: 0.92, 1.08). There was weak evidence of heterogeneity in the hazard ratio for retinal venular caliber, which may be attributable to differences in follow-up strategies across studies. Inclusion of retinal venular caliber in prediction models containing traditional stroke risk factors reassigned 10.1\% of people at intermediate risk into different, mostly lower, risk categories.

}, keywords = {Aged, Fluorescein Angiography, Humans, Middle Aged, Predictive Value of Tests, Proportional Hazards Models, Retinal Artery, Retinal Vein, Retinal Vessels, Risk Factors, Stroke}, issn = {1476-6256}, doi = {10.1093/aje/kwp306}, author = {McGeechan, Kevin and Liew, Gerald and Macaskill, Petra and Irwig, Les and Klein, Ronald and Klein, Barbara E K and Wang, Jie Jin and Mitchell, Paul and Vingerling, Johannes R and de Jong, Paulus T V M and Witteman, Jacqueline C M and Breteler, Monique M B and Shaw, Jonathan and Zimmet, Paul and Wong, Tien Y} } @article {1243, title = {Four novel Loci (19q13, 6q24, 12q24, and 5q14) influence the microcirculation in vivo.}, journal = {PLoS Genet}, volume = {6}, year = {2010}, month = {2010 Oct 28}, pages = {e1001184}, abstract = {

There is increasing evidence that the microcirculation plays an important role in the pathogenesis of cardiovascular diseases. Changes in retinal vascular caliber reflect early microvascular disease and predict incident cardiovascular events. We performed a genome-wide association study to identify genetic variants associated with retinal vascular caliber. We analyzed data from four population-based discovery cohorts with 15,358 unrelated Caucasian individuals, who are members of the Cohort for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium, and replicated findings in four independent Caucasian cohorts (n  =  6,652). All participants had retinal photography and retinal arteriolar and venular caliber measured from computer software. In the discovery cohorts, 179 single nucleotide polymorphisms (SNP) spread across five loci were significantly associated (p<5.0{\texttimes}10(-8)) with retinal venular caliber, but none showed association with arteriolar caliber. Collectively, these five loci explain 1.0\%-3.2\% of the variation in retinal venular caliber. Four out of these five loci were confirmed in independent replication samples. In the combined analyses, the top SNPs at each locus were: rs2287921 (19q13; p  =  1.61{\texttimes}10(-25), within the RASIP1 locus), rs225717 (6q24; p = 1.25{\texttimes}10(-16), adjacent to the VTA1 and NMBR loci), rs10774625 (12q24; p  =  2.15{\texttimes}10(-13), in the region of ATXN2,SH2B3 and PTPN11 loci), and rs17421627 (5q14; p = 7.32{\texttimes}10(-16), adjacent to the MEF2C locus). In two independent samples, locus 12q24 was also associated with coronary heart disease and hypertension. Our population-based genome-wide association study demonstrates four novel loci associated with retinal venular caliber, an endophenotype of the microcirculation associated with clinical cardiovascular disease. These data provide further insights into the contribution and biological mechanisms of microcirculatory changes that underlie cardiovascular disease.

}, keywords = {Adolescent, Adult, Aged, Aged, 80 and over, Cardiovascular Diseases, Child, Child, Preschool, Chromosomes, Human, Pair 12, Chromosomes, Human, Pair 19, Chromosomes, Human, Pair 5, Chromosomes, Human, Pair 6, Cohort Studies, European Continental Ancestry Group, Female, Genetic Loci, Genome-Wide Association Study, Humans, Male, Meta-Analysis as Topic, Microcirculation, Middle Aged, Polymorphism, Single Nucleotide, Retinal Vessels, Young Adult}, issn = {1553-7404}, doi = {10.1371/journal.pgen.1001184}, author = {Ikram, M Kamran and Sim, Xueling and Xueling, Sim and Jensen, Richard A and Cotch, Mary Frances and Hewitt, Alex W and Ikram, M Arfan and Wang, Jie Jin and Klein, Ronald and Klein, Barbara E K and Breteler, Monique M B and Cheung, Ning and Liew, Gerald and Mitchell, Paul and Uitterlinden, Andr{\'e} G and Rivadeneira, Fernando and Hofman, Albert and de Jong, Paulus T V M and van Duijn, Cornelia M and Kao, Linda and Cheng, Ching-Yu and Smith, Albert Vernon and Glazer, Nicole L and Lumley, Thomas and McKnight, Barbara and Psaty, Bruce M and Jonasson, Fridbert and Eiriksdottir, Gudny and Aspelund, Thor and Harris, Tamara B and Launer, Lenore J and Taylor, Kent D and Li, Xiaohui and Iyengar, Sudha K and Xi, Quansheng and Sivakumaran, Theru A and Mackey, David A and Macgregor, Stuart and Martin, Nicholas G and Young, Terri L and Bis, Josh C and Wiggins, Kerri L and Heckbert, Susan R and Hammond, Christopher J and Andrew, Toby and Fahy, Samantha and Attia, John and Holliday, Elizabeth G and Scott, Rodney J and Islam, F M Amirul and Rotter, Jerome I and McAuley, Annie K and Boerwinkle, Eric and Tai, E Shyong and Gudnason, Vilmundur and Siscovick, David S and Vingerling, Johannes R and Wong, Tien Y} } @article {6027, title = {Genetic loci for retinal arteriolar microcirculation.}, journal = {PLoS One}, volume = {8}, year = {2013}, month = {2013}, pages = {e65804}, abstract = {

Narrow arterioles in the retina have been shown to predict hypertension as well as other vascular diseases, likely through an increase in the peripheral resistance of the microcirculatory flow. In this study, we performed a genome-wide association study in 18,722 unrelated individuals of European ancestry from the Cohorts for Heart and Aging Research in Genomic Epidemiology consortium and the Blue Mountain Eye Study, to identify genetic determinants associated with variations in retinal arteriolar caliber. Retinal vascular calibers were measured on digitized retinal photographs using a standardized protocol. One variant (rs2194025 on chromosome 5q14 near the myocyte enhancer factor 2C MEF2C gene) was associated with retinal arteriolar caliber in the meta-analysis of the discovery cohorts at genome-wide significance of P-value <5{\texttimes}10(-8). This variant was replicated in an additional 3,939 individuals of European ancestry from the Australian Twins Study and Multi-Ethnic Study of Atherosclerosis (rs2194025, P-value = 2.11{\texttimes}10(-12) in combined meta-analysis of discovery and replication cohorts). In independent studies of modest sample sizes, no significant association was found between this variant and clinical outcomes including coronary artery disease, stroke, myocardial infarction or hypertension. In conclusion, we found one novel loci which underlie genetic variation in microvasculature which may be relevant to vascular disease. The relevance of these findings to clinical outcomes remains to be determined.

}, keywords = {Aged, Aged, 80 and over, Arterioles, Chromosomes, Human, Pair 5, European Continental Ancestry Group, Female, Genetic Loci, Genome-Wide Association Study, Genotype, Humans, Male, MEF2 Transcription Factors, Microcirculation, Middle Aged, Models, Genetic, Retinal Vessels}, issn = {1932-6203}, doi = {10.1371/journal.pone.0065804}, author = {Sim, Xueling and Jensen, Richard A and Ikram, M Kamran and Cotch, Mary Frances and Li, Xiaohui and Macgregor, Stuart and Xie, Jing and Smith, Albert Vernon and Boerwinkle, Eric and Mitchell, Paul and Klein, Ronald and Klein, Barbara E K and Glazer, Nicole L and Lumley, Thomas and McKnight, Barbara and Psaty, Bruce M and de Jong, Paulus T V M and Hofman, Albert and Rivadeneira, Fernando and Uitterlinden, Andr{\'e} G and van Duijn, Cornelia M and Aspelund, Thor and Eiriksdottir, Gudny and Harris, Tamara B and Jonasson, Fridbert and Launer, Lenore J and Attia, John and Baird, Paul N and Harrap, Stephen and Holliday, Elizabeth G and Inouye, Michael and Rochtchina, Elena and Scott, Rodney J and Viswanathan, Ananth and Li, Guo and Smith, Nicholas L and Wiggins, Kerri L and Kuo, Jane Z and Taylor, Kent D and Hewitt, Alex W and Martin, Nicholas G and Montgomery, Grant W and Sun, Cong and Young, Terri L and Mackey, David A and van Zuydam, Natalie R and Doney, Alex S F and Palmer, Colin N A and Morris, Andrew D and Rotter, Jerome I and Tai, E Shyong and Gudnason, Vilmundur and Vingerling, Johannes R and Siscovick, David S and Wang, Jie Jin and Wong, Tien Y} } @article {6072, title = {Genome-wide association study of retinopathy in individuals without diabetes.}, journal = {PLoS One}, volume = {8}, year = {2013}, month = {2013}, pages = {e54232}, abstract = {

BACKGROUND: Mild retinopathy (microaneurysms or dot-blot hemorrhages) is observed in persons without diabetes or hypertension and may reflect microvascular disease in other organs. We conducted a genome-wide association study (GWAS) of mild retinopathy in persons without diabetes.

METHODS: A working group agreed on phenotype harmonization, covariate selection and analytic plans for within-cohort GWAS. An inverse-variance weighted fixed effects meta-analysis was performed with GWAS results from six cohorts of 19,411 Caucasians. The primary analysis included individuals without diabetes and secondary analyses were stratified by hypertension status. We also singled out the results from single nucleotide polymorphisms (SNPs) previously shown to be associated with diabetes and hypertension, the two most common causes of retinopathy.

RESULTS: No SNPs reached genome-wide significance in the primary analysis or the secondary analysis of participants with hypertension. SNP, rs12155400, in the histone deacetylase 9 gene (HDAC9) on chromosome 7, was associated with retinopathy in analysis of participants without hypertension, -1.3{\textpm}0.23 (beta {\textpm} standard error), p = 6.6{\texttimes}10(-9). Evidence suggests this was a false positive finding. The minor allele frequency was low (\~{}2\%), the quality of the imputation was moderate (r(2) \~{}0.7), and no other common variants in the HDAC9 gene were associated with the outcome. SNPs found to be associated with diabetes and hypertension in other GWAS were not associated with retinopathy in persons without diabetes or in subgroups with or without hypertension.

CONCLUSIONS: This GWAS of retinopathy in individuals without diabetes showed little evidence of genetic associations. Further studies are needed to identify genes associated with these signs in order to help unravel novel pathways and determinants of microvascular diseases.

}, keywords = {Aged, Aged, 80 and over, Female, Genome-Wide Association Study, Genotype, Histone Deacetylases, Humans, Hypertension, Male, Polymorphism, Single Nucleotide, Repressor Proteins, Retinal Diseases}, issn = {1932-6203}, doi = {10.1371/journal.pone.0054232}, author = {Jensen, Richard A and Sim, Xueling and Li, Xiaohui and Cotch, Mary Frances and Ikram, M Kamran and Holliday, Elizabeth G and Eiriksdottir, Gudny and Harris, Tamara B and Jonasson, Fridbert and Klein, Barbara E K and Launer, Lenore J and Smith, Albert Vernon and Boerwinkle, Eric and Cheung, Ning and Hewitt, Alex W and Liew, Gerald and Mitchell, Paul and Wang, Jie Jin and Attia, John and Scott, Rodney and Glazer, Nicole L and Lumley, Thomas and McKnight, Barbara and Psaty, Bruce M and Taylor, Kent and Hofman, Albert and de Jong, Paulus T V M and Rivadeneira, Fernando and Uitterlinden, Andr{\'e} G and Tay, Wan-Ting and Teo, Yik Ying and Seielstad, Mark and Liu, Jianjun and Cheng, Ching-Yu and Saw, Seang-Mei and Aung, Tin and Ganesh, Santhi K and O{\textquoteright}Donnell, Christopher J and Nalls, Mike A and Wiggins, Kerri L and Kuo, Jane Z and van Duijn, Cornelia M and Gudnason, Vilmundur and Klein, Ronald and Siscovick, David S and Rotter, Jerome I and Tai, E Shong and Vingerling, Johannes and Wong, Tien Y} }