@article {1350, title = {Vitamin D, parathyroid hormone, and sudden cardiac death: results from the Cardiovascular Health Study.}, journal = {Hypertension}, volume = {58}, year = {2011}, month = {2011 Dec}, pages = {1021-8}, abstract = {

Recent studies have demonstrated greater risks of cardiovascular events and mortality among persons who have lower 25-hydroxyvitamin D (25-OHD) and higher parathyroid hormone (PTH) levels. We sought to evaluate the association between markers of mineral metabolism and sudden cardiac death (SCD) among the 2312 participants from the Cardiovascular Health Study who were free of clinical cardiovascular disease at baseline. We estimated associations of baseline 25-OHD and PTH concentrations individually and in combination with SCD using Cox proportional hazards models after adjustment for demographics, cardiovascular risk factors, and kidney function. During a median follow-up of 14 years, there were 73 adjudicated SCD events. The annual incidence of SCD was greater among subjects who had lower 25-OHD concentrations, 2 events per 1000 for 25-OHD >=20 ng/mL and 4 events per 1000 for 25-OHD <20 ng/mL. Similarly, SCD incidence was greater among subjects who had higher PTH concentrations, 2 events per 1000 for PTH <65 pg/mL and 4 events per 1000 for PTH >=65 pg/mL. Multivariate adjustment attenuated associations of 25-OHD and PTH with SCD. Finally, 267 participants (11.7\% of the cohort) had high PTH and low 25-OHD concentrations. This combination was associated with a >2-fold risk of SCD after adjustment (hazard ratio: 2.19 [95\% CI: 1.17-4.10]; P=0.017) compared with participants with normal levels of PTH and 25-OHD. The combination of lower 25-OHD and higher PTH concentrations appears to be associated independently with SCD risk among older adults without cardiovascular disease.

}, keywords = {Aged, Cardiovascular Diseases, Comorbidity, Death, Sudden, Cardiac, Diabetes Mellitus, Female, Follow-Up Studies, Humans, Hypertension, Incidence, Kidney, Male, Middle Aged, Minerals, Parathyroid Hormone, Proportional Hazards Models, Risk Factors, Socioeconomic Factors, United States, Vitamin D}, issn = {1524-4563}, doi = {10.1161/HYPERTENSIONAHA.111.179135}, author = {Deo, Rajat and Katz, Ronit and Shlipak, Michael G and Sotoodehnia, Nona and Psaty, Bruce M and Sarnak, Mark J and Fried, Linda F and Chonchol, Michel and de Boer, Ian H and Enquobahrie, Daniel and Siscovick, David and Kestenbaum, Bryan} } @article {7601, title = {Fibroblast Growth Factor 23, Mineral Metabolism, and Adiposity in Normal Kidney Function.}, journal = {J Clin Endocrinol Metab}, volume = {102}, year = {2017}, month = {2017 Apr 01}, pages = {1387-1395}, abstract = {

Context: Obesity is associated with poor bone mineralization and quality. Fibroblast growth factor 23 (FGF23) plays an important role in skeletal physiology.

Objective: To test hypothesis that greater adiposity results in higher FGF23 levels among individuals with normal estimated glomerular filtration rate (eGFR).

Design, Setting, Participants: Cross-sectional analyses among participants with eGFR >=60 mL/min/1.73m2. We assessed the association between crude [body mass index (BMI), waist circumference (WC), and waist-to-hip ratio (WHR); n = 5610] and refined (abdominal adipose tissue area by computed tomography; n = 1313) measures of adiposity and FGF23 using multivariable linear regression.

Main Outcome Measure: Serum FGF23.

Results: FGF23 was higher across BMI categories (BMI <25: 37.7; BMI 25 to 29.99: 38.7; BMI 30 to 39.99: 39.8; BMI >=40: 40.9 pg/mL, unadjusted P trend < 0.0001). The association between BMI and FGF23 was independent of known confounders of FGF23 (adjusted β = +7.2\% higher FGF23 per 10 kg/m2; P < 0.0001). Similar results were observed using WC and WHR. Abdominal adipose tissue area was also independently associated with higher FGF23 (P < 0.01). Notably, the positive associations between FGF23 and adiposity were observed despite the fact that eGFR did not decline and serum phosphate levels did not increase with adiposity.

Conclusion: In a large cohort with normal kidney function, adiposity was associated with higher FGF23 levels independent of known confounders, including eGFR and phosphate. Further studies are needed to evaluate the causes of higher FGF23 in settings of greater adiposity and the potential impact on skeletal health.

}, keywords = {Adiposity, Aged, Aged, 80 and over, Cross-Sectional Studies, Female, Fibroblast Growth Factors, Glomerular Filtration Rate, Humans, Kidney, Male, Middle Aged, Minerals, Renal Insufficiency, Chronic, Risk Factors}, issn = {1945-7197}, doi = {10.1210/jc.2016-3563}, author = {Zaheer, Sarah and de Boer, Ian H and Allison, Matthew and Brown, Jenifer M and Psaty, Bruce M and Robinson-Cohen, Cassianne and Michos, Erin D and Ix, Joachim H and Kestenbaum, Bryan and Siscovick, David and Vaidya, Anand} }