Geriatrics

Renal function reduces progressively throughout life. If one doesn’t die of another disease then chronic kidney disease is probably the final cause of death. Aged persons frequently suffer from reduced kidney function or chronic kidney disease, which may also be accompanied by other diseases such as diabetes or cardiovascular problems. In a geriatric department, and when treating old people in general, measurement of kidney function is of major importance.

Measuring renal function in aged persons is complicated by reduced muscle mass and age, which are just two of the many factors that influence the measurement of GFR by creatinine. Measurement of cystatin C GFR gives a more precise measurement of GFR in this special patient group.

Chronic Kidney Disease (CKD) is a progressive loss of renal function over a period of months or years. The symptoms of worsening kidney function are unspecific, and might include feeling generally unwell and experiencing a reduced appetite. Often, chronic kidney disease is diagnosed as a result of screening of people known to be at risk of kidney problems, such as those with high blood pressure or diabetes and those with a blood relative with chronic kidney disease. Chronic kidney disease may also be identified when it leads to one of its recognized complications, such as cardiovascular disease, anaemia or pericarditis.

The Importance of Early Detection and Treatment of CKD
There is a growing body of evidence that indicates that some of the negative outcomes of chronic kidney disease can be averted with early diagnosis and treatment. Unfortunately, it has also been reported that chronic kidney disease is significantly under-diagnosed and under-treated [10,11]. In an effort to improve early diagnosis, the National Kidney Foundation has issued standardized clinical practice guidelines according to the Kidney Disease Quality Initiative (K/DOQI). In these guidelines and recommendations the primary measure of renal function is the glomerular filtration rate (GFR). The table and figure below show the different stages of kidney disease as they develop. Kidney transplantation is required when kidney function reaches stage 5 also known as ESRD (End Stage Renal Disease).

Stages of Kidney Disease following the NKDEP Classification
(National Kidney Disease Education Program)

Classification__ Description of Stage of Kidney Disease_____ GFR Range______________

Normal Healthy kidneys - normal GFR GFR > 90 mL/min/1.73m²

Stage 1 Kidney damage with normal or elevated GFR GFR > 90 mL/min/1.73m²

Stage 2 Kidney damage and mild decrease in GFR GFR of 60 - 89 mL/min/1.73m²

Stage 3 Moderate decrease in GFR GFR of 30 – 59 mL/min/1.73m²

Stage 4 Severe decrease in GFR GFR < 16 – 29 mL/min/1.73m²

Stage 5 Kidney failure - End Stage Renal Disease (ESRD) GFR < 15 mL/min/1.73m²

GERIATRICS and CHRONIC KIDNEY DISEASE (CKD)

Description Irreversibly reduced GFR.

Reason CKD is an irreversible condition giving a seriously reduced quality of life. Condition is caused predominantly by old age, life-style diseases and poor family history.

Total procedures Same as GFR. 1000 million (2008) and growing at 6-10% annually.

Occurrence Reduced GFR is a normal development of aging. Reduced GFR in the general population is associated with diabetes, obesity, high blood pressure and a family history of heart and kidney failure.

Risk group The aged, persons with life-style diseases, persons with poor family history.

Recommendation[6,7,11] There is a growing body of evidence that some of the negative outcomes of chronic kidney disease can be averted with early diagnosis and treatment [6]. Unfortunately, it has also been reported that chronic kidney disease is significantly under-diagnosed and under-treated [7,11].

Recommendation[7,8] Glomerular filtration rate (GFR) represents the best overall index of kidney function [7], and the National Kidney Foundation has recommended that clinical laboratories routinely report an estimate of GFR [7,8].

References

6. Serum Cystatin C Predicts Progression of Subclinical Coronary Atherosclerosis in Individuals With Type 1 Diabetes. Diabetes 2007:November:vol 56

7. National Kidney Foundation. K/DOQI clinical practice guidelines for chronic kidney disease: evaluation, classification, and stratification. Am J Kidney Dis 2002:39 (Suppl 1):1-246

8. European best practice guidelines expert group on haemodialysis, European Renal Association. Section I. Measurement of renal function, when to refer and when to start dialysis. Nephrol Dial Transplant 2002:17 (Suppl 7):7-15.

10. United States Renal Data Systems

11. National Kidney Disease Education Program

Classification__	Description of Stage of Kidney Disease_____	GFR Range______________
Normal	Healthy kidneys - normal GFR	GFR > 90 mL/min/1.73m²
Stage 1	Kidney damage with normal or elevated GFR	GFR > 90 mL/min/1.73m²
Stage 2	Kidney damage and mild decrease in GFR	GFR of 60 - 89 mL/min/1.73m²
Stage 3	Moderate decrease in GFR	GFR of 30 – 59 mL/min/1.73m²
Stage 4	Severe decrease in GFR	GFR < 16 – 29 mL/min/1.73m²
Stage 5	Kidney failure - End Stage Renal Disease (ESRD)	GFR < 15 mL/min/1.73m²

Description	Irreversibly reduced GFR.
Reason	CKD is an irreversible condition giving a seriously reduced quality of life. Condition is caused predominantly by old age, life-style diseases and poor family history.
Total procedures	Same as GFR. 1000 million (2008) and growing at 6-10% annually.
Occurrence	Reduced GFR is a normal development of aging. Reduced GFR in the general population is associated with diabetes, obesity, high blood pressure and a family history of heart and kidney failure.
Risk group	The aged, persons with life-style diseases, persons with poor family history.
Recommendation[6,7,11]	There is a growing body of evidence that some of the negative outcomes of chronic kidney disease can be averted with early diagnosis and treatment [6]. Unfortunately, it has also been reported that chronic kidney disease is significantly under-diagnosed and under-treated [7,11].
Recommendation[7,8]	Glomerular filtration rate (GFR) represents the best overall index of kidney function [7], and the National Kidney Foundation has recommended that clinical laboratories routinely report an estimate of GFR [7,8].

Geriatrics

Stages of Kidney Disease following the NKDEP Classification (National Kidney Disease Education Program)

GERIATRICS and CHRONIC KIDNEY DISEASE (CKD)

References

Further reading

Stages of Kidney Disease following the NKDEP Classification
(National Kidney Disease Education Program)