Relationship of S.Creatinine to Chronic Kidney Disease ( CKD)

Chronic Kidney Disease (CKD) is increasing globally and also in Kerala. The commonest cause of CKD is due to diabetes. CKD to a great extend is not curable. They undergo progresses to reach the ESRD through five stages. First stage is a the laboratory diagnosis. Micro albuminuria is the earliest sign of Glomerular Capillary dysfunction and seen very much in diabetic patients. Microalbuminuria, more than 30 mgs / day denotes glomerular dysfunction. CKD is detected usually in the third stage, when the albumin is seen in the urine, 24 hrs urine protienuria exceeds 150 mgs. In stage IV & V Serum creatinine, blood urea increases . God has given us two kidneys and both kidneys work together as a collective function of @ 26 lakhs of Nephrons. If you donate a kidney or remove a kidney or if 50 % of both kidneys are damaged due to any disease, creatinine does not increase. When creatinine increases more than 1.4 mg % constantly, as seen in different laboratories, done by auto analyzers -it signifies 60% of Nephronal dysfunction. Once CKD is detected evaluation has to be done.

Serum Creatinine (S.Cr) and its Relevance

Chronic Kidney Disease (CKD)

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How do we diagnose CKD?
Routine urine examination, 24 hrs urine examination, blood tests like S. Cr / urea, uricacid, cholesterol, Calcium, PO4, Parathyroid hormone and Ultra sound scan are needed to evaluate the CKD. Final diagnosis is by kidney Biopsy which is done under Ultra Sound Scan guidance. CKD can be categorized into two groups from treatment point of view. First one, there is no specific treatment available example diabetic kidney disease where diabetes is to be controlled and CKD is to be treated with non specific medical and other supportive therapy. In second one, we can give specific therapies with cortico-steroids, other immunosuppressive medications like MMF or Tacrolimus. SLE , some of the IgA Nephropathy, various primary kidney diseases producing Nephrotc Syndrome fall in this category. Anticipation, awareness and early detection of CKD and its complications are important to consider this specific therapy. Specific therapy varies from institution to institution on the conventional and convinced way of treatment by the treating Doctor. Review of the CKD periodically and at the beginning is very necessary. Obstruction of the kidney due to stones or any another cause, like enlarged prostate has to be looked into. In elderly persons we have to look into undetected asymptomatic bone malignancies like multiple myloma which are known to produce kidney disease. In women, collagen diseases, in particular SLE has to be look for. Stones continue to affect the kidneys in different ways. Uric acid kidney stones and uricacid nephropathy is a condition which can be controlled and stone growth and new stone formation can be prevented.

How can we prevent the progression of the kidney disease ?
Diet control – diet control is important in the control of production of the waste materials like Urea, Creatinine, Potassium, Phosphorus and fluid accumulation. Daily weight has to be noted. Un explained weight gain means accumulation of the fluid intake or by the fluid which is in the food. Fluid accumulation manifests as swelling in the body especially face and leg more so in the evening. This can occur with increased fluid intake than that of urine output or patient has less urine output compared to steady fluid intake. As daily measurement of Intake output is difficult, steady weight is important. Intake of fluid has to be on an individualized basis on that day for that patient. In general if you have intake equal to that of output one should not theoretically put on weight or accumulate water.

Protein Intake we all know that the metabolic end product of protein synthesis is uric acid , urea and creatinine. Everyone needs protein for body metabolism as well as for the amino acid production. In general we allow 0.45 gm per kg wt. That means a 60kg person can have up to 25 – 30gm of protein. Vegetable proteins are better than non veg protein. Protein content may be increased proportionately if there is a significant protein leak in the urine through the kidney filters. So protein content of the food has to be adjusted in such a way that the blood protein / albumin also remains in normal range.

What is 25 -30 gms of protein content? Equivalent of one egg white, one glass milk, one piece of fish and other regular food . Various charts for protein content of food is available and you can refer to find out more details.

Pottassium (K+) Kidney eliminates K+ and therefore K+ containing fruits have to be reduced as the CKD enhances.Normal K+ is 3.5 to 4.5 Meq / L . Diabtetic patients have more inability to excrete K+_ due to certain metabolic rasons. This matter gets complicated when we use medicines like ARB – like Repace, telmisartan and Olmisartan. K+ pairing diuretic has to be used carefully. Metabolic acidosis also produces shift of K from inside the cell to blood . If K+ goes beyond a level, K+ removing powders are available, known as K+ , Calcium resins.

Salt intake is important, Extra salt produces water accumulation and swelling. Most of the CKD patients will have to reduce salt intake because they have edema and hypertension. There are few kidney diseases where salt is lost in the urine and they are called “Salt loosing Nephropathy”. Extra salt has to be administered depending on the patients BP, edema and weight loss or gain. In general we advise CKD patients not to take extra salt unless it is indicated otherwise by the treating Doctor.

Fat in general is not good for health and it gives high Cholesterol and triglycerides. CKD patients loosing weight and if their Cholesterol is controlled can have moderate amount of oil & fat.

Apart from diet there are many other factors which can also used manipulate the progress of CKD .

Blood Sugar Control
Blood sugar control is very important in diabetic patients. Once CKD Progress and creatinine increases above 2..0 mgs insulin is the drug of choice. Newer medications like glitazones are safer among the tablets which are used for diabetes. Tablets produces significant, prolonged hypoglycemia and that is the reason why they are not recommended in CKD. Insulin may produce hypo glycemia. more frequently but the severity is less and the duration is very short. Different types of insulins are available and it has to be used again on a individualized basis, two or three times depends on the needs . Ultimately control of Blood Sugar is a very important fact or which prevents progression of the Macro – Microvascular diseases of the body like Retinopathy and Nephropathy.

Blood Pressure Control
Blood Pressure control is another factor which is very important in the management of CKD. BP is considered as a fuel which is being added on to the burning kidney due to various primary diseases or diabetic kidney diseases. BP should be controlled. Use multiple low dose drugs as all medications have side effects and should be checked periodically. Standing BP is very important. Take the BP regularly in the sitting possession. There could be postural BP fall in Diabetic patients. Dose may have to be adjusted in such a way that sitting BP is controlled to normal. Studies have shown that if the BP is controlled to low normal, progression of the Kidney disease is less, compared to other patients who are on the high normal or are hypertensive.

Calcium Phosphorus and Mineral Bone Disease is gaining a importance. We find that many people are vit D3 deficient. PO4 comes from the diet, especially milk and non vegetarian diet. Kidney is the site at which Vitamin D3 is activated into its active form, which absorbs calcium from the gut and deposits in the bone. Prolonged low calcium produces increased Parathyroid Hormone (iPTH) which is known to produce prurites, refractory CCF and worsening of renal Anaemia. Therefore Calcium , Phospherus estimation are to be done periodically. Low Calcium is the commonest cause of low back ache, stress factors. CKD patients are all advised Calcium and active Vitamin D3 to prevent the hypo calcemia.

Anemia is known to occur in kidney diseases. As the Creatinine increases the erythropoitin (EPO) which is produced in kidneys will be less and anemia worsens. Anemia starts as low as when creatinine 1.7 mg % level. CKD patients need erythropoitin administration. Short acting and long acting EPOs are available . We recommend use of good brands than biosimilars so that the erythropoysis is effective. In addition to the erythropoietin, iron is essential. Iron can be taken as tablets or IV. Blood iron levels can be estimated and corrective dose can be administered. In addition CKD patients are given Folic acid, Vit B1 B12 as a supplement to have more formation.

Uric acid is another point of concern. In CKD uric acid level will increase and can get deposited in the joint producing gouty arthritis. Uric acid is known to produce stones in the kidney worsening of CKD. It is better to keep the uric acid below 7 mg %. New drugs like Febuxostat are available which doesn’t produce reactions like allopurinol!.

Immunisation CKD patients need hepatitis B vaccination. Because of their low immunogenicity, double dose of vaccination is recommended. They are also recommended vaccinations against for chicken pox, pneumococcal infections producing pneumonia. Personal hygiene, and environmental hygiene are very important to prevent many food born, water born infections.

As CKD worsens Renal Replacement Therapy (RRT) has to be planned. RRT is recommended when the Creatinine crosses 5mg% where the eGfr is less than 10 ml / mt. Many patients tolerate uremia with high values of Creatinine of 10- 12 mg% and are asymptomatic. Pre emptive transplantation can be done and that is better than being on many months / years of dialysis. For this one has o identify a suitable donor , get permission. Transplant work up should start when S. Creatinine crosses 5 mg %

Dialysis are of Two types, Peritoneal dialysis and Haemo dialysis. Now that we have got many centers in the periphery with good quality of dialysis, haemo dialysis is gaining popularity. If you don’t have transplantation plans or no donor is available or if the finance is not ready, it is better to do AV Fistula , as a blood access for dialysis. Fistula takes 4 -6 weeks take for maturation depends on patient’s artery and vein.

Transplantation (Tx) has to be planned and preemptive Tx is the ideal. You need a donor - live related, live unrelated and now we have cadaver transplantation (Cd Tx) from the brain dead. KNOS (Kerala Network for Organ Sharing programme) promotes organ donation after brain death. In Kerala more than 180 transplantations have been done in the last 1 year successfully. When you do transplantation, we have to plan for PRA (Panel Reactive Antibody) which detects, if recipient / patients has got antibodies against the general population. If you are a PRA +ve, then you have to select a donor who is not reacting with the patient’s blood ( DSA –ve).

Can diabetes patients undergo kidney transplantation ?
Yes, As diabetes worsens they get macro vascular disease producing coronary problem, brain ischemia, less blood supply to the legs. They may have to be evaluated by the cardiologist for cardiac fitness with the coronary angiogram. Coronary angiogram (CAG) is done only once the patient has entered dialysis. Other wise the dye used for coronary studies are harmful and can produce acute worsening of the existing kidney function. CABG or PTCA (stenting) is to done if needed and after that go for renal transplantation. During angiogram, Iliac vessels can be studied (vessels, going to the leg where the new kidney is going to be attached.

Hepatitis C is emerging as a major problem in the dialysis patients. There are many units with increasing number of HCV . In Kerala Hepititis C infection is due to Genome I (there are 5 types ) In Genome I, the response to the interferon therapy is poor. Cost effectiveness and the benefit of interferon therapy is less and therefore the interferone therapy in pretransplant CKD patients is now becoming optional.

CKD though a trouble shooter for the health of the patient, CKDs are slow progressive. You have time to manipulate all the preventable factors in the progression of the complication of CKD. You have to correct the Anemia, Blood Sugar, Blood Pressure , Calcium, you may vaccinate against many known diseases, you can treat the infection which occur more in the CKD patients and eventually one can avail renal replacement therapy (RRT).

General Physicians have got a big role to play as you see the patient every month. When CKD is detected ,Patient may be referred to a Nephrologist to get CKD evaluated and take a line of management. After that patient should go back to the practitioner / physician and they will be treating the patient in consultation. Monthly reviews have to be done. When the CKD advances to Stage IV / Creatinine increases more than 3-4 mgs, patient may have to be under the care of Nephrologist. A combined effort by various specialties are needed in the management of CKD patients in its early detection, complications and preventing the progression of CKD.