Hyperphosphatemia in Children With Chronic Kidney Disease
Hyperphosphatemia in Children With Chronic Kidney Disease
"Chronic Kidney Disease-Mineral and Bone Disorder " is a systemic disorder of mineral and
 bone metabolism, due to chronic kidney disease that is manifested by either one or a
 combination of the following :

 1. Abnormalities of calcium, phosphate, parathyroid hormone or vitamin D metabolism

 2. Vascular and/or soft tissue calcification.

 3. Abnormalities in bone turnover, metabolism, volume, linear growth or strength. According
 to glomerular filtration rate , Kidney Disease Improving Global Outcomesclassify chronic
 kidney disease into 5 stages,stage 5 also known as End Stage Renal disease is defined as
 glomerular filtration rate less than 15 ml/Min/1.73 m2, or the need for renal
 replacement therapy for survival The kidney plays a major role in phosphate
 homoeostasis. The kidneys excrete the total net amount of absorbed phosphate.Under
 normal physiological condition phosphate is freely filtered through the glomerulus. The
 majority (85-90%) of filtered phosphate undergoes tubular reabsorption primarily in
 proximal tubules.

 Progressive renal insufficiency leads to hyperphosphatemia, hypocalcemia, and secondary
 hyperparathyroidism .

 Hyperphosphatemia known as hidden killer in chronic kidney disease defined as an abnormally
 high serum phosphate concentration of >1.46 mmol/L (4.5 mg/dL). Its long term complications
 are renal osteodystrophy, hyperparathyroidism, and increased cardiovascular calcification
 leading to increased mortality and morbidity .

 High serum phosphate can interact with calcium to precipitate calcium phosphate salts in
 non-skeletal tissues Calcification generally occurs in the blood vessels, heart valves,
 myocardium, and other soft tissues .

 Cardiovascular calcification is probably the main reason for the high prevalence of
 cardiovascular diseases in chronic kidney disease patients Studies have shown that
 hyperphosphatemia is associated with increased vascular stiffening and arterial and valvular
 calcification This is postulated to be caused by elevated serum phosphorus promoting the
 transformation of vascular smooth muscle cells into an osteoblast phenotype that can
 mineralize These vascular calcification also lead to left ventricular hypertrophy by
 decreasing vascular compliance . Poor control of mineral metabolism also has been associated
 with functional and structural cardiac abnormalities Efforts to reduce morbidity and
 mortality associated with Chronic Kidney Disease-Mineral and Bone Disorder are therefore
 primarily directed at controlling hyperphosphatemia via diet, phosphorus binders, and
 dialysis

 Dialysis alone is inadequate in assisting hemodialysis patients to obtain and maintain normal
 serum phosphate levels . So, other methods of achieving prescribed levels of serum phosphate
 in hemodialysis patients include the use of phosphate binders and phosphorus dietary
 restrictions.:

 Phosphate binders have been approved by the Federal Drug Administration (FDA) for patients
 treated with maintenance dialysis, and calcium-containing salts are used worldwide not only
 for the control of hyperphosphatemia but also as a source of supplemental calcium. Several
 calcium salts are commercially available, including calcium carbonate, calcium acetate, and
 calcium citrate Sevelamer hydrochloride is a recently developed phosphate binder, which is a
 quaternary amine anion exchanger without calcium or aluminum. Sevelamer is effective in
 controlling hyperphosphatemia without increasing the calcium load in chronic hemodialysis
 patients In addition to its effects on serum phosphorous levels, sevelamer has been shown to
 decrease total serum cholesterol and low-density lipoprotein cholesterol and to increase
 high-density lipoprotein levels . These effects may offer additional benefits in reducing
 cardiovascular complications in patients with end-stage renal disease.

 Controlling abnormal laboratory parameters such as calcium ,phosphate and parathyroid hormone
 as well as preventing the progression of extraskeletal calcification is considered a major
 component for prevention of the bone disease and other related morbidities and hopefully
 mortality in chronic kidney disease patients
Inclusion Criteria:

 -  Children aged from 6 to 18 years

 -  With end stage renal disease on regular hemodialysis,

 -  With hyperphosphatemia (serum phosphorus > 4.5mg/dL ).

 -  Both genders will be included

 -  Given informed concent.

 Exclusion Criteria:

 -  - Children < 6 years,

 -  Severe Gastrointestinal disorder,

 -  Known hypersensitivity to phosphate binders,

 -  Inability or rejection to give informed consent,

 -  Normal serum phosphate level.