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Phosphorus Control
The Link Between Bone and Cardiovascular Disease in Chronic Kidney Disease
a report by
João M Frazão
Nephrologist, Hospital S João, and Assistant Professor of Medicine, University of Porto Medical School
During the last few years there have been developments in the management mortality.
5,6
Hyperphosphataemia and elevated calcium–phosphorus
of bone and mineral disorders in chronic kidney disease stage V product are associated with cardiovascular calcification.
7,8
haemodialysis patients. The knowledge that these bone and mineral
abnormalities have a major impact on morbidity and mortality requires the The use of calcium-containing phosphate binders has been associated
practising nephrologist to pay close attention to controlling these with progression of vascular calcification in prevalent and incident
alterations. In dialysis patients, bone metabolism disorders and their haemodialysis patients compared with the attenuation seen with
treatment strategies are associated with the development of cardiovascular sevelamer, a phosphate binder that does not increase calcium levels
calcifications. Kidney Disease: Improving Global Outcomes (K/DIGO) has and also reduces low-density lipoprotein (LDL) cholesterol.
9,10
Chertow
recommended a new classification for mineral and bone disorders of chronic et al.
9
reported the results of a randomised parallel-design clinical trial
kidney disease that includes the evaluation of extra-skeletal calcifications. comparing sevelamer with calcium-based phosphorus binders in 200
haemodialysis patients. Sevelamer- and calcium-based compounds
The presence of arterial calcifications in chronic kidney disease stage V provided similar control of serum phosphorus and calcium–phosphorus
patients on regular haemodialysis is an independent predictor of
subsequent cardiovascular morbidity and mortality. The objective of this
article is to describe the most recent data supporting the hypothesis of
a link between bone disease related to chronic kidney disease and the
The presence of elevated serum
development of cardiovascular calcifications in dialysis patients.
phosphorus levels in chronic kidney
Vascular Calcifications and Mortality
disease stage V patients is positively
Cardiovascular calcification is an independent predictor of mortality.
Several authors have now reported a strong positive association
associated with increased mortality.
between the presence and extent of vascular calcification and both
cardiovascular and all-cause mortality.
1–3
Vascular calcification is also
associated with increased cardiovascular morbidity. Raggi et al.
4
reported that previous myocardial infarction, angina pectoris and product. The group treated with sevelamer received an average binder
known coronary artery disease were all more common in chronic dose of 6.5±2.9g per day and the group treated with calcium-based
kidney disease stage V patients with extensive calcification. binders received an average binder dose of 4.3±1.9g per day (4.6 and
3.9g per day of calcium acetate or calcium carbonate, respectively).
The presence of elevated serum phosphorus levels in chronic kidney The calcium-based group had more frequent episodes of
disease stage V patients is positively associated with increased hypercalcaemia compared with the sevelamer group (43 and 17%,
respectively). Suppression of intact parathyroid hormone (PTH)
secretion below the 150–300pg/ml range was more common at the
João M Frazão is a Nephrologist in the Hospital Sao João
end of the study in the calcium-based binders group (57 versus 30%),
in Porto, Portugal, and an Assistant Professor of Medicine
at the University of Porto. He is a member of many
despite the protocol specifying reduction or cessation of vitamin D for
professional societies, including the European Renal intact PTH levels below 150pg/ml. The total cholesterol and LDL
Association–European Dialysis and Transplant Association
cholesterol levels decreased significantly in the sevelamer-treated
(ERA-EDTA) and the International, American and
Portuguese Societies of Nephrology. He was elected Vice
group compared with no change in the calcium binders group.
President of the Portuguese Society of Nephrology in 2003
and has been a Council Member of the ERA-EDTA since
Of relevance, the electron beam computed tomography (EBCT)
2005. Professor Frazão is on the Editorial Boards of Nephrology, Dialysis, Transplantation
and the Portuguese Journal of Nephrology. His publications include over 35 peer-reviewed performed at the beginning of the study detected a prevalence of
papers in the area of chronic renal failure and secondary hyperparathyroidism, as well
coronary artery calcification of 83% and aortic calcification of 80%
as a number of book chapters. He graduated in medicine from the Medical School of
the University of Lisbon, Portugal, in 1986, and received his PhD in medicine from the
of the study patients. There was a significant progression of the
University of Porto in 1999. His post-graduate training in nephrology took place at the coronary artery and aortic calcification EBCT score at weeks 26 and 52
West Los Angeles Veterans Affairs Medical Center and at the University of California, Los
in the group treated with calcium-containing binders, despite the
Angeles. Professor Frazão gained his certification in internal medicine and nephrology from
the American Board of Internal Medicine (ABIM).
use of an average dose of calcium carbonate of only 3.9g per day
(1.56g of elemental calcium). There was no significant progression in
E: jmmdfrazao@netcabo.pt
the sevelamer-treated group.
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