@article {6587, title = {Association of a cystatin C gene variant with cystatin C levels, CKD, and risk of incident cardiovascular disease and mortality.}, journal = {Am J Kidney Dis}, volume = {63}, year = {2014}, month = {2014 Jan}, pages = {16-22}, abstract = {

BACKGROUND: Carriers of the T allele of the single-nucleotide polymorphism rs13038305 tend to have lower cystatin C levels and higher cystatin C-based estimated glomerular filtration rate (eGFRcys). Adjusting for this genetic effect on cystatin C concentrations may improve GFR estimation, reclassify cases of chronic kidney disease (CKD), and strengthen risk estimates for cardiovascular disease (CVD) and mortality.

STUDY DESIGN: Observational.

SETTING \& POPULATION: 4 population-based cohorts: Atherosclerosis Risk in Communities (ARIC), Cardiovascular Health (CHS), Framingham Heart (FHS), and Health, Aging, and Body Composition (Health ABC) studies.

PREDICTORS: We estimated the association of rs13038305 with eGFRcys and serum creatinine-based eGFR (eGFRcr) and performed longitudinal analyses of the associations of eGFRcys with mortality and cardiovascular events following adjustment for rs13038305.

OUTCOMES: We assessed reclassification by genotype-adjusted eGFRcys across CKD categories: <45, 45-59, 60-89, and >= 90 mL/min/1.73 m(2). We compared mortality and CVD outcomes in those reclassified to a worse eGFRcys category with those unaffected. Results were combined using fixed-effect inverse-variance meta-analysis.

RESULTS: In 14,645 participants, each copy of the T allele of rs13038305 (frequency, 21\%) was associated with a 6.4\% lower cystatin C concentration, 5.5-mL/min/1.73 m(2) higher eGFRcys, and 36\% [95\% CI, 29\%-41\%] lower odds of CKD. Associations with CVD (HR, 1.17; 95\% CI, 1.14-1.20) and mortality (HR, 1.22; 95\% CI, 1.19-1.24) per 10-mL/min/1.73 m(2) lower eGFRcys were similar with or without rs13038305 adjustment. 1,134 (7.7\%) participants were reclassified to a worse CKD category following rs13038305 adjustment, and rates of CVD and mortality were higher in individuals who were reclassified. However, the overall net reclassification index was not significant for either outcome, at 0.009 (95\% CI, -0.003 to 0.022) for mortality and 0.014 (95\% CI, 0.0 to 0.028) for CVD.

LIMITATIONS: rs13038305 explains only a small proportion of cystatin C variation.

CONCLUSIONS: Statistical adjustment can correct a genetic bias in GFR estimates based on cystatin C in carriers of the T allele of rs13038305 and result in changes in disease classification. However, on a population level, the effects on overall reclassification of CKD status are modest.

}, keywords = {Aged, Bias, Biomarkers, Cardiovascular Diseases, Creatinine, Cystatin C, Female, Genetic Variation, Glomerular Filtration Rate, Humans, Male, Middle Aged, Polymorphism, Single Nucleotide, Renal Insufficiency, Chronic, Risk Assessment, Risk Factors, Severity of Illness Index, Statistics as Topic, Survival Rate}, issn = {1523-6838}, doi = {10.1053/j.ajkd.2013.06.015}, author = {O{\textquoteright}Seaghdha, Conall M and Tin, Adrienne and Yang, Qiong and Katz, Ronit and Liu, Yongmei and Harris, Tamara and Astor, Brad and Coresh, Josef and Fox, Caroline S and Kao, W H Linda and Shlipak, Michael G} } @article {9456, title = {Association of omega 3 polyunsaturated fatty acids with incident chronic kidney disease: pooled analysis of 19 cohorts.}, journal = {BMJ}, volume = {380}, year = {2023}, month = {2023 Jan 18}, pages = {e072909}, abstract = {

OBJECTIVE: To assess the prospective associations of circulating levels of omega 3 polyunsaturated fatty acid (n-3 PUFA) biomarkers (including plant derived α linolenic acid and seafood derived eicosapentaenoic acid, docosapentaenoic acid, and docosahexaenoic acid) with incident chronic kidney disease (CKD).

DESIGN: Pooled analysis.

DATA SOURCES: A consortium of 19 studies from 12 countries identified up to May 2020.

STUDY SELECTION: Prospective studies with measured n-3 PUFA biomarker data and incident CKD based on estimated glomerular filtration rate.

DATA EXTRACTION AND SYNTHESIS: Each participating cohort conducted de novo analysis with prespecified and consistent exposures, outcomes, covariates, and models. The results were pooled across cohorts using inverse variance weighted meta-analysis.

MAIN OUTCOME MEASURES: Primary outcome of incident CKD was defined as new onset estimated glomerular filtration rate <60 mL/min/1.73 m. In a sensitivity analysis, incident CKD was defined as new onset estimated glomerular filtration rate <60 mL/min/1.73 m and <75\% of baseline rate.

RESULTS: 25 570 participants were included in the primary outcome analysis and 4944 (19.3\%) developed incident CKD during follow-up (weighted median 11.3 years). In multivariable adjusted models, higher levels of total seafood n-3 PUFAs were associated with a lower incident CKD risk (relative risk per interquintile range 0.92, 95\% confidence interval 0.86 to 0.98; P=0.009, I=9.9\%). In categorical analyses, participants with total seafood n-3 PUFA level in the highest fifth had 13\% lower risk of incident CKD compared with those in the lowest fifth (0.87, 0.80 to 0.96; P=0.005, I=0.0\%). Plant derived α linolenic acid levels were not associated with incident CKD (1.00, 0.94 to 1.06; P=0.94, I=5.8\%). Similar results were obtained in the sensitivity analysis. The association appeared consistent across subgroups by age (>=60 <60 years), estimated glomerular filtration rate (60-89 >=90 mL/min/1.73 m), hypertension, diabetes, and coronary heart disease at baseline.

CONCLUSIONS: Higher seafood derived n-3 PUFA levels were associated with lower risk of incident CKD, although this association was not found for plant derived n-3 PUFAs. These results support a favourable role for seafood derived n-3 PUFAs in preventing CKD.

}, keywords = {alpha-Linolenic Acid, Fatty Acids, Omega-3, Fatty Acids, Unsaturated, Humans, Middle Aged, Prospective Studies, Renal Insufficiency, Chronic, Risk Factors}, issn = {1756-1833}, doi = {10.1136/bmj-2022-072909}, author = {Ong, Kwok Leung and Marklund, Matti and Huang, Liping and Rye, Kerry-Anne and Hui, Nicholas and Pan, Xiong-Fei and Rebholz, Casey M and Kim, Hyunju and Steffen, Lyn M and van Westing, Anniek C and Geleijnse, Johanna M and Hoogeveen, Ellen K and Chen, Yun-Yu and Chien, Kuo-Liong and Fretts, Amanda M and Lemaitre, Rozenn N and Imamura, Fumiaki and Forouhi, Nita G and Wareham, Nicholas J and Birukov, Anna and J{\"a}ger, Susanne and Kuxhaus, Olga and Schulze, Matthias B and de Mello, Vanessa Derenji and Tuomilehto, Jaakko and Uusitupa, Matti and Lindstr{\"o}m, Jaana and Tintle, Nathan and Harris, William S and Yamasaki, Keisuke and Hirakawa, Yoichiro and Ninomiya, Toshiharu and Tanaka, Toshiko and Ferrucci, Luigi and Bandinelli, Stefania and Virtanen, Jyrki K and Voutilainen, Ari and Jayasena, Tharusha and Thalamuthu, Anbupalam and Poljak, Anne and Bustamante, Sonia and Sachdev, Perminder S and Senn, Mackenzie K and Rich, Stephen S and Tsai, Michael Y and Wood, Alexis C and Laakso, Markku and Lankinen, Maria and Yang, Xiaowei and Sun, Liang and Li, Huaixing and Lin, Xu and Nowak, Christoph and Arnl{\"o}v, Johan and Riserus, Ulf and Lind, Lars and Le Goff, M{\'e}lanie and Samieri, Cecilia and Helmer, Catherine and Qian, Frank and Micha, Renata and Tin, Adrienne and K{\"o}ttgen, Anna and de Boer, Ian H and Siscovick, David S and Mozaffarian, Dariush and Wu, Jason HY} }