Background: Calcium-phosphate levels, linked to vascular dysfunction in chronic kidney disease, may represent novel risk factors for coronary heart disease, stroke, and death in community-dwelling adults. Methods: We tested this hypothesis over 12.6 years of follow-up in the prospective, community-based Atherosclerosis Risk in Communities Study (n = 15,732). Results: At baseline, mean (SD) values were 9.8 (0.4) mg/dL for serum calcium, 3.4 (0.5) mg/dL for serum phosphate, 33.6 (5.3) mg2/dL2 for calcium-phosphate product, 54.2 (5.7) years for age, and 93.1 (21.5) mL/min per 1.73 m2 for glomerular filtration rate (GFR). Shared associations of calcium, phosphate, and calcium-phosphate product included older age, female sex, African American race, cigarette-years, current cigarette smoking, low body mass index, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, low serum albumin, low GFR, low caloric intake, and phosphorus intake. With adjustment for age, demographic characteristics, comorbid conditions, albumin, and GFR, calcium-associated hazards ratios for coronary heart disease, stroke, and death were, respectively, 1.01 (95% confidence interval 0.96-1.06), 1.16 (1.07-1.26, P = .0005), and 1.03 (0.98-1.08); phosphate-associated hazards ratios were 1.03 (0.98-1.08), 1.11 (1.02-1.21, P = .0219), and 1.14 (1.09-1.20, P < .0001); calcium-phosphate product-associated hazards ratios were 1.03 (0.98-1.08), 1.15 (1.05-1.26, P = .0017), and 1.15 (1.09-1.20, P < .0001). Conclusions: Although calcium, phosphate, and calcium-phosphate product levels exhibit complex associations with traditional cardiovascular risk factors and outcomes, they may be potentially modifiable risk factors for stroke and death in community-dwelling adults.
Bibliographical noteFunding Information:
This study was supported by the United States Renal Data System under contract no. HHSN267200715002C (National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD). Doctor Foley has received honoraria from Genzyme (Cambridge, MA) and Abbott (Abbott Park, IL). Doctor Collins has received consulting fees from Roche (Basel, Switzerland) and Amgen (Thousand Oaks, CA). Doctor Kalra has received educational grants from Amgen and Genzyme. Doctor Ishani has no conflicts of interest.
Copyright 2008 Elsevier B.V., All rights reserved.