@article {1224, title = {Common variants in the calcium-sensing receptor gene are associated with total serum calcium levels.}, journal = {Hum Mol Genet}, volume = {19}, year = {2010}, month = {2010 Nov 01}, pages = {4296-303}, abstract = {

Serum calcium levels are tightly regulated. We performed genome-wide association studies (GWAS) in population-based studies participating in the CHARGE Consortium to uncover common genetic variations associated with total serum calcium levels. GWAS of serum calcium concentrations was performed in 20 611 individuals of European ancestry for \~{}2.5 million genotyped and imputed single-nucleotide polymorphisms (SNPs). The SNP with the lowest P-value was rs17251221 (P = 2.4 * 10(-22), minor allele frequency 14\%) in the calcium-sensing receptor gene (CASR). This lead SNP was associated with higher serum calcium levels [0.06 mg/dl (0.015 mmol/l) per copy of the minor G allele] and accounted for 0.54\% of the variance in serum calcium concentrations. The identification of variation in CASR that influences serum calcium concentration confirms the results of earlier candidate gene studies. The G allele of rs17251221 was also associated with higher serum magnesium levels (P = 1.2 * 10(-3)), lower serum phosphate levels (P = 2.8 * 10(-7)) and lower bone mineral density at the lumbar spine (P = 0.038), but not the femoral neck. No additional genomic loci contained SNPs associated at genome-wide significance (P < 5 * 10(-8)). These associations resemble clinical characteristics of patients with familial hypocalciuric hypercalcemia, an autosomal-dominant disease arising from rare inactivating mutations in the CASR gene. We conclude that common genetic variation in the CASR gene is associated with similar but milder features in the general population.

}, keywords = {Adult, Calcium, Female, Humans, Male, Middle Aged, Polymorphism, Single Nucleotide, Receptors, Calcium-Sensing}, issn = {1460-2083}, doi = {10.1093/hmg/ddq342}, author = {O{\textquoteright}Seaghdha, Conall M and Yang, Qiong and Glazer, Nicole L and Leak, Tennille S and Dehghan, Abbas and Smith, Albert V and Kao, W H Linda and Lohman, Kurt and Hwang, Shih-Jen and Johnson, Andrew D and Hofman, Albert and Uitterlinden, Andr{\'e} G and Chen, Yii-Der Ida and Brown, Edward M and Siscovick, David S and Harris, Tamara B and Psaty, Bruce M and Coresh, Josef and Gudnason, Vilmundur and Witteman, Jacqueline C and Liu, Yong Mei and Kestenbaum, Bryan R and Fox, Caroline S and K{\"o}ttgen, Anna} } @article {1392, title = {Fibroblast growth factor-23 and death, heart failure, and cardiovascular events in community-living individuals: CHS (Cardiovascular Health Study).}, journal = {J Am Coll Cardiol}, volume = {60}, year = {2012}, month = {2012 Jul 17}, pages = {200-7}, abstract = {

OBJECTIVES: This study sought to determine the association of fibroblast growth factor (FGF)-23 with death, heart failure (HF), and cardiovascular disease (CVD) in the general population, as well as the influence of chronic kidney disease (CKD) in this setting.

BACKGROUND: FGF-23 increases renal phosphorus excretion and inhibits vitamin D activation. In end-stage renal disease, high FGF-23 levels are associated with mortality. The association of FGF-23 with death, HF, and CVD in the general population, and the influence of CKD in this setting, are unknown.

METHODS: Plasma FGF-23 was measured in 3,107 community-living persons >= 65 years of age in 1996 and 1997, and participants were followed through 2008. HF and CVD events were adjudicated by a panel of experts. Associations of FGF-23 with each outcome were evaluated using Cox proportional hazards models, and we tested whether associations differed by CKD status.

RESULTS: Both lower estimated glomerular filtration rate and higher urine albumin to creatinine ratios were associated with high FGF-23 at baseline. During 10.5 years (median) follow-up, there were 1,730 deaths, 697 incident HF events, and 797 incident CVD events. Although high FGF-23 concentrations were associated with each outcome in combined analyses, the associations were consistently stronger for those with CKD (p interactions all <0.006). In the CKD group (n = 1,128), the highest FGF-23 quartile had adjusted hazards ratios (HR) of 1.87 (95\% confidence interval [CI]: 1.47 to 2.38) for all-cause death, 1.94 (95\% CI: 1.32 to 2.83) for incident HF, and 1.49 (95\% CI: 1.02 to 2.18) for incident CVD events compared with the lowest quartile. Corresponding HRs in those without CKD (n = 1,979) were 1.29 (95\% CI: 1.05 to 1.59), 1.37 (95\% CI: 0.99 to 1.89), and 1.07 (95\% CI: 0.79 to 1.45).

CONCLUSIONS: FGF-23, a hormone involved in phosphorous and vitamin D homeostasis, is independently associated with all-cause death and incident HF in community-living older persons. These associations appear stronger in persons with CKD.

}, keywords = {Aged, Aged, 80 and over, Biomarkers, Female, Fibroblast Growth Factors, Heart Failure, Humans, Kidney Function Tests, Male, Mortality, Renal Insufficiency, Chronic, United States}, issn = {1558-3597}, doi = {10.1016/j.jacc.2012.03.040}, author = {Ix, Joachim H and Katz, Ronit and Kestenbaum, Bryan R and de Boer, Ian H and Chonchol, Michel and Mukamal, Kenneth J and Rifkin, Dena and Siscovick, David S and Sarnak, Mark J and Shlipak, Michael G} } @article {6239, title = {Fibroblast growth factor 23, the ankle-brachial index, and incident peripheral artery disease in the Cardiovascular Health Study.}, journal = {Atherosclerosis}, volume = {233}, year = {2014}, month = {2014 Mar}, pages = {91-6}, abstract = {

BACKGROUND: Fibroblast growth factor 23 (FGF23) has emerged as a novel risk factor for mortality and cardiovascular events. Its association with the ankle-brachial index (ABI) and clinical peripheral artery disease (PAD) is less known.

METHODS: Using data (N = 3143) from the Cardiovascular Health Study (CHS), a cohort of community dwelling adults >65 years of age, we analyzed the cross-sectional association of FGF23 with ABI and its association with incident clinical PAD events during 9.8 years of follow up using multinomial logistic regression and Cox proportional hazards models respectively.

RESULTS: The prevalence of cardiovascular disease (CVD) and traditional risk factors like diabetes, coronary artery disease, and heart failure increased across higher quartiles of FGF23. Compared to those with ABI of 1.1-1.4, FGF23 per doubling at baseline was associated with prevalent PAD (ABI < 0.9) although this association was attenuated after adjusting for CVD risk factors, and kidney function (OR 0.91, 95\% CI 0.76-1.08). FGF23 was not associated with high ABI (>1.4) (OR 1.06, 95\% CI 0.75-1.51). Higher FGF23 was associated with incidence of PAD events in unadjusted, demographic adjusted, and CVD risk factor adjusted models (HR 2.26, 95\% CI 1.28-3.98; highest versus lowest quartile). The addition of estimated glomerular filtration and urine albumin to creatinine ratio to the model however, attenuated these findings (HR 1.46, 95\% CI, 0.79-2.70).

CONCLUSIONS: In community dwelling older adults, FGF23 was not associated with baseline low or high ABI or incident PAD events after adjusting for confounding variables. These results suggest that FGF23 may primarily be associated with adverse cardiovascular outcomes through non atherosclerotic mechanisms.

}, keywords = {Aged, Ankle Brachial Index, Cardiovascular Diseases, Cross-Sectional Studies, Fibroblast Growth Factors, Humans, Incidence, Peripheral Arterial Disease, Risk Factors}, issn = {1879-1484}, doi = {10.1016/j.atherosclerosis.2013.12.015}, author = {Garimella, Pranav S and Ix, Joachim H and Katz, Ronit and Chonchol, Michel B and Kestenbaum, Bryan R and de Boer, Ian H and Siscovick, David S and Shastri, Shani and Hiramoto, Jade S and Shlipak, Michael G and Sarnak, Mark J} } @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 {6770, title = {Urinary uromodulin, kidney function, and cardiovascular disease in elderly adults.}, journal = {Kidney Int}, volume = {88}, year = {2015}, month = {2015 Nov}, pages = {1126-34}, abstract = {

Urinary uromodulin (uUMOD) is the most common secreted tubular protein in healthy adults. However, the relationship between uUMOD and clinical outcomes is still unclear. Here we measured uUMOD in 192 participants of the Cardiovascular Health Study with over a 30\% decline in estimated glomerular filtration rate (eGFR) over 9 years, 54 with incident end-stage renal disease (ESRD), and in a random subcohort of 958 participants. The association of uUMOD with eGFR decline was evaluated using logistic regression and with incident ESRD, cardiovascular disease, heart failure, and mortality using Cox proportional regression. Mean age was 78 years and median uUMOD was 25.8 μg/ml. In a case-control study evaluating eGFR decline (192 cases and 231 controls), each 1-s.d. higher uUMOD was associated with a 23\% lower odds of eGFR decline (odds ratio 0.77 (95\% CI 0.62-0.96)) and a 10\% lower risk of mortality (hazard ratio 0.90 (95\% CI 0.83-0.98)) after adjusting for demographics, eGFR, albumin/creatinine ratio, and other risk factors. There was no risk association of uUMOD with ESRD, cardiovascular disease, or heart failure after multivariable adjustment. Thus, low uUMOD levels may identify persons at risk of progressive kidney disease and mortality above and beyond established markers of kidney disease, namely eGFR and the albumin/creatinine ratio. Future studies need to confirm these results and evaluate whether uUMOD is a marker of tubular health and/or whether it plays a causal role in preserving kidney function.

}, keywords = {Aged, Aged, 80 and over, Albuminuria, Biomarkers, Cardiovascular Diseases, Case-Control Studies, Creatinine, Disease Progression, Female, Glomerular Filtration Rate, Heart Failure, Humans, Incidence, Kidney Failure, Chronic, Male, Proportional Hazards Models, Uromodulin}, issn = {1523-1755}, doi = {10.1038/ki.2015.192}, author = {Garimella, Pranav S and Biggs, Mary L and Katz, Ronit and Ix, Joachim H and Bennett, Michael R and Devarajan, Prasad and Kestenbaum, Bryan R and Siscovick, David S and Jensen, Majken K and Shlipak, Michael G and Chaves, Paulo H M and Sarnak, Mark J} } @article {6990, title = {Fibroblast Growth Factor-23 and Frailty in Elderly Community-Dwelling Individuals: The Cardiovascular Health Study.}, journal = {J Am Geriatr Soc}, volume = {64}, year = {2016}, month = {2016 Feb}, pages = {270-6}, abstract = {

OBJECTIVES: To evaluate whether fibroblast growth factor 23 (FGF-23) is related to frailty and to characterize the nature of their joint association with mortality.

DESIGN: Cross-sectional analysis for frailty and longitudinal cohort analysis for mortality.

SETTING: Cardiovascular Health Study.

PARTICIPANTS: Community-dwelling individuals (N = 2,977; mean age 77.9 {\textpm} 4.7, 40\% male, 83\% white).

MEASUREMENTS: The predictor was serum FGF-23 concentration (C-terminal enzyme-linked immunosorbent assay), and the outcomes were frailty status (determined according to frailty phenotype criteria of weight loss, weakness, exhaustion, slowness, and low physical activity) and mortality. Multinomial logistic regression was used to assess the cross-sectional association between FGF-23 and frailty and prefrailty, adjusting for demographic characteristics, cardiovascular disease and risk factors, and kidney markers. Proportional hazards Cox proportional hazards regression was used to assess the association between FGF-23, frailty, and all-cause mortality.

RESULTS: Mean estimated glomerular filtration rate (eGFR) was 64 {\textpm} 17 mL/min per 1.73 m(2) . Median FGF-23 was 70.3 RU/mL (interquartile range 53.4-99.2); 52\% were prefrail, and 13\% were frail. After multivariate adjustment, each doubling in FGF-23 concentration was associated with 38\% (95\% confidence interval (CI) = 17-62\%) higher odds of frailty than of nonfrailty and 16\% (95\% CI = 3-30\%) higher odds of prefrailty. FGF-23 (hazard ratio (HR) = 1.16, 95\% CI = 1.10-1.23) and frailty (HR = 1.82, 95\% CI = 1.57-2.12) were independently associated with mortality, but neither association was meaningfully attenuated when adjusted for the other.

CONCLUSION: In a large cohort of older adults, higher FGF-23 was independently associated with prevalent frailty and prefrailty. FGF-23 and frailty were independent and additive risk factors for mortality. FGF-23 may be a marker for functional outcomes.

}, keywords = {Aged, Anthropometry, Biomarkers, Cardiovascular Diseases, Cross-Sectional Studies, Enzyme-Linked Immunosorbent Assay, Female, Fibroblast Growth Factors, Frail Elderly, Glomerular Filtration Rate, Humans, Independent Living, Longitudinal Studies, Male, Phenotype, Risk Factors, Surveys and Questionnaires}, issn = {1532-5415}, doi = {10.1111/jgs.13951}, author = {Beben, Tomasz and Ix, Joachim H and Shlipak, Michael G and Sarnak, Mark J and Fried, Linda F and Hoofnagle, Andrew N and Chonchol, Michel and Kestenbaum, Bryan R and de Boer, Ian H and Rifkin, Dena E} }