@article {1302, title = {Association of serum phosphate levels with aortic valve sclerosis and annular calcification: the cardiovascular health study.}, journal = {J Am Coll Cardiol}, volume = {58}, year = {2011}, month = {2011 Jul 12}, pages = {291-7}, abstract = {

OBJECTIVES: This study was conducted to evaluate mineral metabolism markers as potential risk factors for calcific aortic valve disease.

BACKGROUND: Mineral metabolism disturbances are common among older people and may contribute to cardiac valvular calcification. Associations of serum mineral metabolism markers with cardiac valvular calcification have not been evaluated in a well-characterized general population of older adults.

METHODS: We measured serum levels of phosphate, calcium, parathyroid hormone, and 25-hydroxyvitamin D in 1,938 Cardiovascular Health Study participants who were free of clinical cardiovascular disease and who underwent echocardiographic measurements of aortic valve sclerosis (AVS), mitral annular calcification (MAC), and aortic annular calcification (AAC). We used logistic regression models to estimate associations of mineral metabolism markers with AVS, MAC, and AAC after adjustment for relevant confounding variables, including kidney function.

RESULTS: The respective prevalences of AVS, MAC, and AAC were 54\%, 39\%, and 44\%. Each 0.5 mg/dl higher serum phosphate concentration was associated with greater adjusted odds of AVS (odds ratio [OR]: 1.17, 95\% confidence interval [CI]: 1.04 to 1.31, p = 0.01), MAC (OR: 1.12, 95\% CI: 1.00 to 1.26, p = 0.05), and AAC (OR: 1.12, 95\% CI: 0.99 to 1.25, p = 0.05). In contrast, serum calcium, parathyroid hormone, and 25-hydroxyvitamin D concentrations were not associated with aortic or mitral calcification.

CONCLUSIONS: Higher serum phosphate levels within the normal range were associated with valvular and annular calcification in a community-based cohort of older adults. Phosphate may be a novel risk factor for calcific aortic valve disease and warrants further study.

}, keywords = {Aged, Aortic Valve, Calcinosis, Calcium, Female, Heart Valve Diseases, Humans, Male, Mitral Valve, Parathyroid Hormone, Phosphates, Risk Factors, Sclerosis, Vitamin D}, issn = {1558-3597}, doi = {10.1016/j.jacc.2010.11.073}, author = {Linefsky, Jason P and O{\textquoteright}Brien, Kevin D and Katz, Ronit and de Boer, Ian H and Barasch, Eddy and Jenny, Nancy S and Siscovick, David S and Kestenbaum, Bryan} } @article {6399, title = {Fibroblast growth factor-23 and incident atrial fibrillation: the Multi-Ethnic Study of Atherosclerosis (MESA) and the Cardiovascular Health Study (CHS).}, journal = {Circulation}, volume = {130}, year = {2014}, month = {2014 Jul 22}, pages = {298-307}, abstract = {

BACKGROUND: Fibroblast growth factor-23 (FGF-23) is a hormone that promotes urinary phosphate excretion and regulates vitamin D metabolism. Circulating FGF-23 concentrations increase markedly in chronic kidney disease and are associated with increased risk of clinical cardiovascular events. FGF-23 may promote atrial fibrillation (AF) by inducing left ventricular hypertrophy and diastolic and left atrial dysfunction.

METHODS AND RESULTS: We tested the associations of circulating FGF-23 concentration with incident AF among 6398 participants in the Multi-Ethnic Study of Atherosclerosis (MESA) and 1350 participants in the Cardiovascular Health Study (CHS), all free of clinical cardiovascular disease at baseline. Over a median of 7.7 and 8.0 years of follow-up, we observed 291 and 229 incident AF events in MESA and CHS, respectively. In multivariable Cox proportional hazards models, each 2-fold-higher FGF-23 concentration was associated with a 41\% higher risk of incident AF in MESA (hazard ratio, 1.41; 95\% confidence interval, 1.13-1.76; P=0.003) and a 30\% higher risk of incident AF in CHS (hazard ratio, 1.30; 95\% confidence interval, 1.05-1.61; P=0.016) after adjustment for potential confounding characteristics, including kidney disease. Serum phosphate concentration was significantly associated with incident AF in MESA (hazard ratio, 1.15 per 0.5 mg/dL; 95\% confidence interval, 1.02-1.31; P=0.023) but not CHS. In MESA, an association of low estimated glomerular filtration rate with incident AF was partially attenuated by adjustment for FGF-23.

CONCLUSION: Higher circulating FGF-23 concentration is associated with incident AF and may, in part, explain the link between chronic kidney disease and AF.

}, keywords = {Aged, Aged, 80 and over, Atrial Fibrillation, Comorbidity, Ethnic Groups, Female, Fibroblast Growth Factor 3, Follow-Up Studies, Glomerular Filtration Rate, Heart Failure, Humans, Hypertrophy, Left Ventricular, Male, Middle Aged, Phosphates, Proportional Hazards Models, Renal Insufficiency, Chronic, Risk Factors, United States, Ventricular Dysfunction, Left, Ventricular Remodeling, Vitamin D}, issn = {1524-4539}, doi = {10.1161/CIRCULATIONAHA.113.005499}, author = {Mathew, Jehu S and Sachs, Michael C and Katz, Ronit and Patton, Kristen K and Heckbert, Susan R and Hoofnagle, Andrew N and Alonso, Alvaro and Chonchol, Michel and Deo, Rajat and Ix, Joachim H and Siscovick, David S and Kestenbaum, Bryan and de Boer, Ian H} }