@article {6070, title = {A genome-wide association study of depressive symptoms.}, journal = {Biol Psychiatry}, volume = {73}, year = {2013}, month = {2013 Apr 01}, pages = {667-78}, abstract = {

BACKGROUND: Depression is a heritable trait that exists on a continuum of varying severity and duration. Yet, the search for genetic variants associated with depression has had few successes. We exploit the entire continuum of depression to find common variants for depressive symptoms.

METHODS: In this genome-wide association study, we combined the results of 17 population-based studies assessing depressive symptoms with the Center for Epidemiological Studies Depression Scale. Replication of the independent top hits (p<1{\texttimes}10(-5)) was performed in five studies assessing depressive symptoms with other instruments. In addition, we performed a combined meta-analysis of all 22 discovery and replication studies.

RESULTS: The discovery sample comprised 34,549 individuals (mean age of 66.5) and no loci reached genome-wide significance (lowest p = 1.05{\texttimes}10(-7)). Seven independent single nucleotide polymorphisms were considered for replication. In the replication set (n = 16,709), we found suggestive association of one single nucleotide polymorphism with depressive symptoms (rs161645, 5q21, p = 9.19{\texttimes}10(-3)). This 5q21 region reached genome-wide significance (p = 4.78{\texttimes}10(-8)) in the overall meta-analysis combining discovery and replication studies (n = 51,258).

CONCLUSIONS: The results suggest that only a large sample comprising more than 50,000 subjects may be sufficiently powered to detect genes for depressive symptoms.

}, keywords = {Aged, Aged, 80 and over, Chromosomes, Human, Pair 5, Depression, Female, Genetic Predisposition to Disease, Genome-Wide Association Study, Humans, Male, Middle Aged, Polymorphism, Single Nucleotide}, issn = {1873-2402}, doi = {10.1016/j.biopsych.2012.09.033}, author = {Hek, Karin and Demirkan, Ayse and Lahti, Jari and Terracciano, Antonio and Teumer, Alexander and Cornelis, Marilyn C and Amin, Najaf and Bakshis, Erin and Baumert, Jens and Ding, Jingzhong and Liu, Yongmei and Marciante, Kristin and Meirelles, Osorio and Nalls, Michael A and Sun, Yan V and Vogelzangs, Nicole and Yu, Lei and Bandinelli, Stefania and Benjamin, Emelia J and Bennett, David A and Boomsma, Dorret and Cannas, Alessandra and Coker, Laura H and de Geus, Eco and De Jager, Philip L and Diez-Roux, Ana V and Purcell, Shaun and Hu, Frank B and Rimma, Eric B and Hunter, David J and Jensen, Majken K and Curhan, Gary and Rice, Kenneth and Penman, Alan D and Rotter, Jerome I and Sotoodehnia, Nona and Emeny, Rebecca and Eriksson, Johan G and Evans, Denis A and Ferrucci, Luigi and Fornage, Myriam and Gudnason, Vilmundur and Hofman, Albert and Illig, Thomas and Kardia, Sharon and Kelly-Hayes, Margaret and Koenen, Karestan and Kraft, Peter and Kuningas, Maris and Massaro, Joseph M and Melzer, David and Mulas, Antonella and Mulder, Cornelis L and Murray, Anna and Oostra, Ben A and Palotie, Aarno and Penninx, Brenda and Petersmann, Astrid and Pilling, Luke C and Psaty, Bruce and Rawal, Rajesh and Reiman, Eric M and Schulz, Andrea and Shulman, Joshua M and Singleton, Andrew B and Smith, Albert V and Sutin, Angelina R and Uitterlinden, Andr{\'e} G and V{\"o}lzke, Henry and Widen, Elisabeth and Yaffe, Kristine and Zonderman, Alan B and Cucca, Francesco and Harris, Tamara and Ladwig, Karl-Heinz and Llewellyn, David J and R{\"a}ikk{\"o}nen, Katri and Tanaka, Toshiko and van Duijn, Cornelia M and Grabe, Hans J and Launer, Lenore J and Lunetta, Kathryn L and Mosley, Thomas H and Newman, Anne B and Tiemeier, Henning and Murabito, Joanne} } @article {7017, title = {Vitamin D and the risk of dementia and Alzheimer disease.}, journal = {Neurology}, volume = {83}, year = {2014}, month = {2014 Sep 2}, pages = {920-8}, abstract = {

OBJECTIVE: To determine whether low vitamin D concentrations are associated with an increased risk of incident all-cause dementia and Alzheimer disease.

METHODS: One thousand six hundred fifty-eight elderly ambulatory adults free from dementia, cardiovascular disease, and stroke who participated in the US population-based Cardiovascular Health Study between 1992-1993 and 1999 were included. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were determined by liquid chromatography-tandem mass spectrometry from blood samples collected in 1992-1993. Incident all-cause dementia and Alzheimer disease status were assessed during follow-up using National Institute of Neurological and Communicative Disorders and Stroke/Alzheimer{\textquoteright}s Disease and Related Disorders Association criteria.

RESULTS: During a mean follow-up of 5.6 years, 171 participants developed all-cause dementia, including 102 cases of Alzheimer disease. Using Cox proportional hazards models, the multivariate adjusted hazard ratios (95\% confidence interval [CI]) for incident all-cause dementia in participants who were severely 25(OH)D deficient (<25 nmol/L) and deficient (>=25 to <50 nmol/L) were 2.25 (95\% CI: 1.23-4.13) and 1.53 (95\% CI: 1.06-2.21) compared to participants with sufficient concentrations (>=50 nmol/L). The multivariate adjusted hazard ratios for incident Alzheimer disease in participants who were severely 25(OH)D deficient and deficient compared to participants with sufficient concentrations were 2.22 (95\% CI: 1.02-4.83) and 1.69 (95\% CI: 1.06-2.69). In multivariate adjusted penalized smoothing spline plots, the risk of all-cause dementia and Alzheimer disease markedly increased below a threshold of 50 nmol/L.

CONCLUSION: Our results confirm that vitamin D deficiency is associated with a substantially increased risk of all-cause dementia and Alzheimer disease. This adds to the ongoing debate about the role of vitamin D in nonskeletal conditions.

}, keywords = {Aged, Alzheimer Disease, Dementia, Female, Follow-Up Studies, Humans, Incidence, Male, Proportional Hazards Models, Risk Factors, United States, Vitamin D, Vitamin D Deficiency}, issn = {1526-632X}, doi = {10.1212/WNL.0000000000000755}, author = {Littlejohns, Thomas J and Henley, William E and Lang, Iain A and Annweiler, Cedric and Beauchet, Olivier and Chaves, Paulo H M and Fried, Linda and Kestenbaum, Bryan R and Kuller, Lewis H and Langa, Kenneth M and Lopez, Oscar L and Kos, Katarina and Soni, Maya and Llewellyn, David J} } @article {6999, title = {Vitamin D and Memory Decline: Two Population-Based Prospective Studies.}, journal = {J Alzheimers Dis}, volume = {50}, year = {2016}, month = {2016}, pages = {1099-108}, abstract = {

BACKGROUND: Vitamin D deficiency has been linked with dementia risk, cognitive decline, and executive dysfunction. However, the association with memory remains largely unknown.

OBJECTIVE: To investigate whether low serum 25-hydroxyvitamin D (25(OH)D) concentrations are associated with memory decline.

METHODS: We used data on 1,291 participants from the US Cardiovascular Health Study (CHS) and 915 participants from the Dutch Longitudinal Aging Study Amsterdam (LASA) who were dementia-free at baseline, had valid vitamin D measurements, and follow-up memory assessments. The Benton Visual Retention Test (in the CHS) and Rey{\textquoteright}s Auditory Verbal Learning Test (in the LASA) were used to assess visual and verbal memory, respectively.

RESULTS: In the CHS, those moderately and severely deficient in serum 25(OH)D changed -0.03 SD (95\% CI: -0.06 to 0.01) and -0.10 SD (95\% CI: -0.19 to -0.02) per year respectively in visual memory compared to those sufficient (p = 0.02). In the LASA, moderate and severe deficiency in serum 25(OH)D was associated with a mean change of 0.01 SD (95\% CI: -0.01 to 0.02) and -0.01 SD (95\% CI: -0.04 to 0.02) per year respectively in verbal memory compared to sufficiency (p = 0.34).

CONCLUSIONS: Our findings suggest an association between severe vitamin D deficiency and visual memory decline but no association with verbal memory decline. They warrant further investigation in prospective studies assessing different memory subtypes.

}, issn = {1875-8908}, doi = {10.3233/JAD-150811}, author = {Ku{\'z}ma, El{\.z}bieta and Soni, Maya and Littlejohns, Thomas J and Ranson, Janice M and van Schoor, Natasja M and Deeg, Dorly J H and Comijs, Hannie and Chaves, Paulo H M and Kestenbaum, Bryan R and Kuller, Lewis H and Lopez, Oscar L and Becker, James T and Langa, Kenneth M and Henley, William E and Lang, Iain A and Ukoumunne, Obioha C and Llewellyn, David J} } @article {7126, title = {Vitamin D and Risk of Neuroimaging Abnormalities.}, journal = {PLoS One}, volume = {11}, year = {2016}, month = {2016}, pages = {e0154896}, abstract = {

Vitamin D deficiency has been linked with an increased risk of incident all-cause dementia and Alzheimer{\textquoteright}s disease. The aim of the current study was to explore the potential mechanisms underlying these associations by determining whether low vitamin D concentrations are associated with the development of incident cerebrovascular and neurodegenerative neuroimaging abnormalities. The population consisted of 1,658 participants aged >=65 years from the US-based Cardiovascular Health Study who were free from prevalent cardiovascular disease, stroke and dementia at baseline in 1992-93. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were determined by liquid chromatography-tandem mass spectrometry from blood samples collected at baseline. The first MRI scan was conducted between 1991-1994 and the second MRI scan was conducted between 1997-1999. Change in white matter grade, ventricular grade and presence of infarcts between MRI scan one and two were used to define neuroimaging abnormalities. During a mean follow-up of 5.0 years, serum 25(OH)D status was not significantly associated with the development of any neuroimaging abnormalities. Using logistic regression models, the multivariate adjusted odds ratios (95\% confidence interval) for worsening white matter grade in participants who were severely 25(OH)D deficient (<25 nmol/L) and deficient (>=25-50 nmol/L) were 0.76 (0.35-1.66) and 1.09 (0.76-1.55) compared to participants with sufficient concentrations (>=50 nmol/L). The multivariate adjusted odds ratios for ventricular grade in participants who were severely 25(OH)D deficient and deficient were 0.49 (0.20-1.19) and 1.12 (0.79-1.59) compared to those sufficient. The multivariate adjusted odds ratios for incident infarcts in participants who were severely 25(OH)D deficient and deficient were 1.95 (0.84-4.54) and 0.73 (0.47-1.95) compared to those sufficient. Overall, serum vitamin D concentrations could not be shown to be associated with the development of cerebrovascular or neurodegenerative neuroimaging abnormalities in Cardiovascular Health Study participants.

}, issn = {1932-6203}, doi = {10.1371/journal.pone.0154896}, author = {Littlejohns, Thomas J and Kos, Katarina and Henley, William E and Lang, Iain A and Annweiler, Cedric and Beauchet, Olivier and Chaves, Paulo H M and Kestenbaum, Bryan R and Kuller, Lewis H and Langa, Kenneth M and Lopez, Oscar L and Llewellyn, David J} } @article {7565, title = {Bivariate Genome-Wide Association Study of Depressive Symptoms with Type 2 Diabetes and Quantitative Glycemic Traits.}, journal = {Psychosom Med}, year = {2017}, month = {2017 Dec 27}, abstract = {

OBJECTIVE: Shared genetic background may explain phenotypic associations between depression and Type-2-Diabetes (T2D). We aimed to study, on a genome-wide level, if genetic correlation and pleiotropic loci exist between depressive symptoms and T2D or glycemic traits.

METHODS: We estimated SNP-based heritability and analyzed genetic correlation between depressive symptoms and T2D and glycemic traits with the LD Score Regression (LDSC) by combining summary statistics of previously conducted meta-analyses for depressive symptoms by CHARGE consortium (N = 51,258), T2D by Diagram consortium (N = 34,840 patients and 114,981 controls), fasting glucose, fasting insulin, HOMA-β, and HOMA-IR by MAGIC consortium (N = 58,074). Finally, we investigated pleiotropic loci using a bivariate GWAS approach with summary statistics from GWAS meta-analyses and reported loci with genome-wide significant bivariate association p-value (p < 5x10). Biological annotation and function of significant pleiotropic SNPs were assessed in several databases.

RESULTS: The SNP-based heritability ranged from 0.04 to 0.10 in each individual trait. In the LDSC analyses, depressive symptoms showed no significant genetic correlation with T2D or glycemic traits (p > 0.37). Yet, we identified pleiotropic genetic variations for depressive symptoms and T2D (in the IGF2BP2, CDKAL1, CDKN2B-AS, and PLEKHA1 genes), and fasting glucose (in the MADD, CDKN2B-AS, PEX16, and MTNR1B genes).

CONCLUSIONS: We found no significant overall genetic correlations between depressive symptoms, T2D or glycemic traits suggesting major differences in underlying biology of these traits. Yet, several potential pleiotropic loci were identified between depressive symptoms, T2D and fasting glucose suggesting that previously established phenotypic associations may be partly explained by genetic variation in these specific loci.

}, issn = {1534-7796}, doi = {10.1097/PSY.0000000000000555}, author = {Haljas, Kadri and Amare, Azmeraw T and Alizadeh, Behrooz Z and Hsu, Yi-Hsiang and Mosley, Thomas and Newman, Anne and Murabito, Joanne and Tiemeier, Henning and Tanaka, Toshiko and van Duijn, Cornelia and Ding, Jingzhong and Llewellyn, David J and Bennett, David A and Terracciano, Antonio and Launer, Lenore and Ladwig, Karl-Heinz and Cornelis, Marylin C and Teumer, Alexander and Grabe, Hans and Kardia, Sharon L R and Ware, Erin B and Smith, Jennifer A and Snieder, Harold and Eriksson, Johan G and Groop, Leif and R{\"a}ikk{\"o}nen, Katri and Lahti, Jari} } @article {7348, title = {Coronary Artery Bypass Graft Surgery and Dementia Risk in the Cardiovascular Health Study.}, journal = {Alzheimer Dis Assoc Disord}, year = {2017}, month = {2017 Mar 03}, abstract = {

INTRODUCTION: The association between history of coronary artery bypass graft surgery (CABG) and dementia risk remains unclear.

METHODS: We conducted a prospective cohort analysis using data on 3155 elderly adults free from prevalent dementia from the US population-based Cardiovascular Health Study (CHS) with adjudicated incident all-cause dementia, Alzheimer disease (AD), vascular dementia (VaD), and mixed dementia.

RESULTS: In the CHS, the hazard ratio (HR) for all-cause dementia was 1.93 [95\% confidence interval (CI), 1.36-2.74] for those with CABG history compared with those with no CABG history after adjustment for potential confounders. Similar HRs were observed for AD (HR=1.71; 95\% CI, 0.98-2.98), VaD (HR=1.42; 95\% CI, 0.56-3.65), and mixed dementia (HR=2.73; 95\% CI, 1.55-4.80). The same pattern of results was observed when these CHS findings were pooled with a prior prospective study, the pooled HRs were 1.96 (95\% CI, 1.42-2.69) for all-cause dementia, 1.71 (95\% CI, 1.04-2.79) for AD and 2.20 (95\% CI, 0.78-6.19) for VaD.

DISCUSSION: Our results suggest CABG history is associated with long-term dementia risk. Further investigation is warranted to examine the causal mechanisms which may explain this relationship or whether the association reflects differences in coronary artery disease severity.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. http://creativecommons.org/licenses/by-nc-nd/4.0/.

}, issn = {1546-4156}, doi = {10.1097/WAD.0000000000000191}, author = {Ku{\'z}ma, El{\.z}bieta and Airdrie, Jac and Littlejohns, Thomas J and Lourida, Ilianna and Thompson-Coon, Jo and Lang, Iain A and Scrobotovici, Monica and Thacker, Evan L and Fitzpatrick, Annette and Kuller, Lewis H and Lopez, Oscar L and Longstreth, William T and Ukoumunne, Obioha C and Llewellyn, David J} }