Quality in Primary Care 2008;16:279–94 # 2008 European Forum for Primary Care International exchange Management of chronic kidney disease in primary health care: position paper of the European Forum for Primary Care Mai Rosenberg Nephrologist and Ass. Professor, Department of Internal Medicine Ruth Kalda Family Doctor and Ass. Professor, Department of Family Medicine University of Tartu, Estonia Vytautas Kasiulevicˇius Family Doctor and Ass. Professor, Department of Family Medicine, University of Vilnius, Lithuania Margus Lember Professor of Internal Medicine, University of Tartu, Estonia Introduction Chronic kidney disease (CKD) is a worldwide public the development of renal failure among those in whom health problem that is often underdiagnosed and the original illness is either inactive or cured.4 The cost undertreated. CKD is a ‘silent’ disease and goes un- of the advanced renal failure and renal replacement noticed because it may not be ‘felt’. Yet it affects many therapy is enormous.5,6 Therefore, early diagnosis and more people than we might imagine: 1 out of 10 adults optimal management of CKD affords many challenges in the world has some form of kidney damage.1 for primary health care in helping to maintain health However, as many as 90% of those who have CKD and quality of life among the population at risk. remain unidentified. High blood pressure and dia- This position paper is based on published reviews betes are the main causes of CKD. It is projected that about CKD management in different stages, and focuses diabetes will increase by 70% by 2025. Therefore, early on key references published since the year 2000. This detection and prevention of the progression of CKD position statement also provides evidence-based screen- for people who also have a very high cardiovascular ing recommendations and interventions for shared risk are extremely important challenges and goals for care between GPs/FDs and specialists. general practitioners/family doctors (GPs/FDs). CKD represents a progressive, irreversible decline in glomerular filtration rate (GFR).2 Most chronic Chronic kidney disease: definition, nephropathies unfortunately lack a specific treatment classification and epidemiology and progress relentlessly to end-stage renal disease (ESRD). Progressive renal function loss is a common phenomenon in renal failure, irrespective of the under- Definition lying cause of the kidney disease.3 The kidney is able to The National Kidney Foundation – Kidney Disease Out- adapt to damage by adaptive hyperfiltration – increas- comes Quality Initiative (NKF-K/DOQI) workgroup ing the filtration in the remaining normal nephrons. has defined CKD as the following,7 which have been As a result, a patient with mild renal insufficiency accepted internationally with some clarifications:8,9 often has a normal or near-normal serum creatinine concentration. Adaptive hyperfiltration, although in- 1 the presence of markers of kidney damage for three itially beneficial, appears to result in long-term dam- months, as defined by structural or functional abnor- age to the glomeruli of the remaining nephrons, which malities of the kidney with or without decreased is manifest by proteinuria and progressive renal in- GFR, that can lead to decreased GFR, manifest by sufficiency. This process appears to be responsible for either pathological abnormalities or other markers 280 M Rosenberg, R Kalda, V Kasiulevicˇius et al of kidney damage, including abnormalities in the Epidemiology of CKD composition of blood or urine, or abnormalities in imaging tests Clinical evaluation for CKD should include eluci- dation of the cause of disease. However, the cause of or: the disease cannot be ascertained in all cases. Also, 2 the presence of GFR <60 ml/min/(1.73 m2) for renal function declines normally with age, and the three months, with or without other signs of exact level of decline at a given age that should be kidney damage as described above. considered pathological is not known. The KD:IGO statement considers GFR less than 60 ml/min to be Based upon representative samples of the US popu- pathological at all ages.10 Cross-sectional studies re- lation,7 the studies have estimated the prevalence of port a slow decline in GFR after the fourth decade of CKD in the general population through measurement life of 0.75 ml/min/(1.73 m2)/year. These changes of markers of kidney damage, such as elevated serum proceed slowly but in the presence of other diseases creatinine concentration, decreased predicted GFR such as diabetes, hypertension and heart disease, the and presence of albuminuria. kidney becomes vulnerable to failure.11 According to the Kidney Disease: improving global Very few of the causes of chronic renal failure are outcomes (KD:IGO) position statement, the use of the completely curable. It is often not necessary to do term ‘disease’ in CKD is consistent with: extensive tests to find a cause, especially when symptoms 1 the need for action to improve outcomes through of renal insufficiency are already present. However, for prevention, detection, evaluation and treatment determining the stage and specific characteristics of the 2 providing a message for public, physician and underlying disease, follow-up of patients and thorough patient education programmes diagnostic work-up is needed. Diabetes is one of the commonest causes of kidney failure after glomerulo- 3 common usage 12–15 3 its use in other conditions defined by findings and nephritis in many countries. The major groups of laboratory tests, such as hypertension, diabetes and diseases leading to ESRD are glomerulonephritis, diabetic hyperlipidaemia.9 nephropathy, hypertension, chronic pyelonephritis and polycystic kidney disease. In different countries the proportions of these diseases as a cause of renal Classification of CKD failure vary: e.g. glomerulonephritis accounts for 22– CKD is classified according to severity, diagnosis, 24% of renal replacement therapy (RRT) patients in treatment and prognosis.9 Five-stage classification is Estonia, Germany, Poland or Finland, but only 11– based on structural and functional criteria regardless 12% in France, Italy or England. Patients of diabetic of the cause and accounting for dialysis and trans- nephropathy form 12% of RRT patients in Italy, 22% plantation (see Table 1). The suffix ‘T’ is used for all in Estonia, 24% in Finland and Poland, 23% in transplant recipients, at any level of GFR, and ‘D’ for Germany, 12% in England, 30% in Japan, and 37% 16–19 dialysis, for CKD stage 5 patients treated with dialysis. in the US. Table 1 Classification of chronic kidney disease10 Stage Description GFR (ml/min/1.73 m2) Related terms 1 Kidney damage with normal 90 Albuminuria; proteinuria; or " GFR haematuria 2 Kidney damage with mild 60–89 Albuminuria; proteinuria; # GFR haematuria 3 Moderate # GFR 30–59 Chronic renal insufficiency; early renal insufficiency 4 Severe # GFR 15–29 Chronic renal insufficiency; late renal insufficiency; pre-end-stage renal failure 5 Kidney failure <15 Renal failure; uraemia; end-stage renal disease Management of CKD in primary health care 281 The use of RRT varies in different countries. There support in many guidelines.22 However, systematic is a rising incidence and prevalence of kidney fail- diabetes screening of members of the general popu- ure,12–15 and the worldwide epidemic of CKD shows lation without symptoms or risk factors has not been no signs of abating in the near future. The exact found to be effective. reasons for the growth of ESRD are unknown. Changes Risk groups for chronic kidney disease are those in the demographics of the population, differences in with the following: disease burden among different racial groups and . a family history of diabetes or hypertension under-recognition of earlier stages and of risk factors . diabetes for CKD may partially explain this growth.8 Recent . hypertension trends show that the rate of increase of new cases of . recurrent urinary tract infections both diabetic and all-cause ESRD has progressively . urinary obstruction levelled off in many countries.13,20 It is therefore . systemic diseases that affect kidneys currently impossible to predict the long-term trend . past or family history of cardiovascular disease. of RRT in Europe. The prevalence of RRT patients/ million inhabitants in 2005 was very different world- The most widely used methods for screening for wide: in Estonia it was 394, in Finland 722, in Sweden kidney disease are: 818, in Germany 1057, in Spain 899, in England 668 1 an analysis of a random urine sample for albumi- and in the US 1590.16,17 nuria It has been shown that CKD affects men more often 2 a serum creatinine measurement to calculate an than women. For example, according to the Finnish estimated GFR, which is an indication of func- Registry for Kidney Diseases, the prevalence of RRT in tioning kidney mass. men was 898 and in women 553/million inhabitants in 2006.17 Since1996,theprevalenceofRRThasincreased It is recommended to use both of these methods, as faster among men (63%) than among women (44%). significant kidney disease can present with diminished The prevalence among the elderly is growing rapidly: GFR or proteinuria, or both.23 Detecting and quan- in the age group 75+ years, the prevalence of RRT has tifying proteinuria is essential to the diagnosis and increased by almost 250% during the past ten years treatment of CKD. Albumin, the predominant protein and 70% during the past five years. In the younger age excreted by the kidney in most types of renal diseases, groups, the prevalence has increased 10–61% in ten can be detected by urine dipstick testing. The protein– years and 4–14% in five years.17 creatinine ratio in an early-morning random urine sample correlates well with 24-hour urine protein excretion, and is much easier to obtain.7 Albuminuria often heralds the onset of diabetic nephropathy; thus Management of chronic kidney this sample is therefore recommended for all patients at risk for kidney disease.