Albuminuria and renal insufficiency prevalence guides population screening: results from the NHANES III

BACKGROUND: A number of screening criteria, applied either at a single point in time or serially, can be used for the purpose of identifying individuals at risk of end-stage renal disease (ESRD). This study focused on two such criteria measured on a single occasion, proteinuria and renal insufficiency, and examined their prevalence in a sample representative of the adult U.S. non-institutionalized population. Such knowledge guides the utility of population screening to prevent ESRD. METHODS: The prevalence of albuminuria (microalbuminuria and macroalbuminuria from a random urine albumin-to-creatinine ratio) and renal insufficiency [glomerular filtration rate (GFR) estimated from serum creatinine] was determined in different age categories in various adult screening groups in the cross-sectional Third National Health and Nutrition Examination Survey (NHANES III). RESULTS: A total of 14,622 adult participants were included in the analysis. In the general population, 8.3% and 1.0% of participants demonstrated microalbuminuria and macroalbuminuria, respectively. To identify one case of albuminuria, one would need to screen three persons with diabetes mellitus, seven non-diabetic hypertensive persons, or six persons over the age of 60. When albuminuria and renal insufficiency were considered together, it was clear that these tests were identifying different segments of the population; 37% of participants with a GFR less than 30 mL/min/1.73 m2 demonstrated no albuminuria. Non-albuminuric renal insufficiency was most evident in the ages of 60 to 79; 34% of diabetics, and 63% of non-diabetic hypertensives with a GFR less than 30 mL/min/1.73 m2 demonstrated no albuminuria. CONCLUSIONS: Albuminuria is prevalent, and when considered together, screening tests of albuminuria and renal insufficiency measured on a single occasion identify different segments of the population. The prevalence of albuminuria and renal insufficiency in populations of interest should be considered, as this knowledge has implications for the effectiveness of screening.     

Prevalence of chronic kidney disease in the Japanese general population

Background

We previously estimated the prevalence of chronic kidney disease (CKD) stages 3–5 at 19.1 million based on data from the Japanese annual health check program for 2000–2004 using the Modification of Diet in Renal Disease (MDRD) equation multiplied by the coefficient 0.881 for the Japanese population. However, this equation underestimates the GFR, particularly for glomerular filtration rates (GFRs) of over 60 ml/min/1.73 m². We did not classify the participants as CKD stages 1 and 2 because we did not obtain proteinuria data for all of the participants. We re-estimated the prevalence of CKD by measuring proteinuria using a dipstick test and by calculating the GFR using a new equation that estimates GFR based on data from the Japanese annual health check program in 2005.

Methods

Data were obtained for 574,024 (male 240,594, female 333,430) participants over 20 years old taken from the general adult population, who were from 11 different prefectures in Japan (Hokkaido, Yamagata, Fukushima, Tochigi, Ibaraki, Tokyo, Kanazawa, Osaka, Fukuoka, Miyazaki and Okinawa) and took part in the annual health check program in 2005. The glomerular filtration rate (GFR) of each participant was computed from the serum creatinine value using a new equation: GFR (ml/min/1.73 m²) = 194 × Age^?0.287 × S-Cr^?1.094 (if female × 0.739). The CKD population nationwide was calculated using census data from 2005. We also recalculated the prevalence of CKD in Japan assuming that the age composition of the population was same as that in the USA.

Results

The prevalence of CKD stages 1, 2, 3, and 4 + 5 were 0.6, 1.7, 10.4 and 0.2% in the study population, which resulted in predictions of 0.6, 1.7, 10.7 and 0.2 million patients, respectively, nationwide. The prevalence of low GFR was significantly higher in the hypertensive and proteinuric populations than it was in the populations without proteinuria or hypertension. The prevalence rate of CKD in Japan was similar to that in the USA when the Japanese general population was age adjusted to the US 2005 population estimate.

Conclusion

About 13% of the Japanese adult population—approximately 13.3 million people—were predicted to have CKD in 2005.     

Association between prehypertension and chronic kidney disease in the Japanese general population

The increased prevalence of chronic kidney disease (CKD) is a consequence of the accumulation of risk factors, one of which is hypertension. Here we assessed the prevalence of CKD according to blood pressure among 232,025 patients in a Japanese nationwide database with a focus on the prevalence and risk factors of CKD in prehypertension. Patients were stratified by blood pressure and included 75,474 with optimal blood pressure (less than 120/80 mm Hg); 59,194 with prehypertension and a normal blood pressure (120-129/80-84 mm Hg) or 46,547 patients with high-normal blood pressure (130-139/85-89 mm Hg); and 50,810 with hypertension (over 140/90 mm Hg without anti-hypertensive drugs). CKD was defined as an estimated glomerular filtration rate of stage 3 or lower or having proteinuria greater than 1+ by a dipstick method. The prevalence of CKD among patients with optimal blood pressure, prehypertension having normal or high-normal blood pressure, and hypertension was 13.9, 15.6, 18.1, and 20.7% in men, and 10.9, 11.6, 12.9, and 15.0% in women, with a significant difference between genders at each strata of blood pressure. In men, but not in women, whose blood pressure was high-normal, the CKD risk was significantly greater (odds ratio 1.11) than those with optimal blood pressure. Obesity (body mass index over 25) was significantly associated with an increased risk of CKD in both men and women (odds ratio 1.43 and 1.26, respectively), and there was an additive effect of obesity and pre-hypertension on CKD risk in men compared with men with optimal blood pressure. Thus, the prevalence of CKD increased with the severity of blood pressure. Prehypertension with high-normal blood pressure, particularly in conjunction with obesity, was found to be an independent risk factor of CKD in men.     

Chronic kidney disease in the general population

End-stage kidney disease (ESKD), defined as the need for dialysis, receipt of a transplant, or death from chronic kidney failure, generally affects fewer than 1% of the population. However ESKD is the end result of chronic kidney disease (CKD), a widely prevalent but often silent condition with elevated risks of cardiovascular morbidity and mortality and a range of metabolic complications. A recently devised classification of CKD has facilitated prevalence estimates that reveal an "iceberg" of CKD in the community, of which dialysis and transplant patients are the tip. Hypertension, smoking, hypercholesterolemia, and obesity, currently among the World Health Organization's (WHO's) top 10 global health risks, are strongly associated with CKD. The factors, together with increasing diabetes prevalence and an aging population, will result in significant global increases in CKD and ESKD patients. Treatments now available effectively reduce the rate of progression of CKD and the extent of comorbid conditions and complications. The challenges are (1) to intervene effectively to reduce the excess burden of cardiovascular morbidity and mortality associated with CKD, (2) to identify those at greatest risk for ESKD and intervene effectively to prevent progression of early CKD, and (3) to ultimately introduce cost-effective primary prevention to reduce the overall burden of CKD. The vast majority of the global CKD burden will be in developing countries, and policy responses must be both practical and sustainable in these settings.     

Relationship between hepatitis C and microalbuminuria: results from the NHANES III

BACKGROUND: Hepatitis C infection is associated with diabetes mellitus and insulin resistance and it is suggested that metabolic syndrome is common in patients with hepatitis C. Microalbuminuria is common in patients with diabetes and metabolic syndrome; however, no studies have examined the relationship between microalbuminuria and hepatitis C infection. METHODS: We conducted a nested case-control study to examine the relationship between nondiabetic subjects with hepatitis C infection and microalbuminuria by using the Third National Health and Nutrition Examination Survey (NHANES III) database. Study cohort consisted of 15,336 adults from the United States who had hepatitis C antibody measured as part of the NHANES III. The prevalence of microalbuminuria and the metabolic syndrome were compared between individuals with positive hepatitis C infection antibody (N= 362) and matched controls (N= 995). Additional analyses were conducted to define the association between hepatitis C infection and microalbuminuria. RESULTS: Prevalence of microalbuminuria in patients with hepatitis C infection was 12.4% and it was significantly higher than in controls (7.5%) (P= 0.001). This difference persisted even after excluding diabetics from the analyses (11.4% vs. 6.7%) (P= 0.001). However, there was no difference in the prevalence of the metabolic syndrome between two groups (19% vs. 19%) (P= 0.9). After controlling for relevant covariates, hepatitis C infection was independently associated with microalbuminuria in subjects without diabetes (odds ratio 1.99, 95% CI 1.38-2.85) (P= 0.008). Older age and African Americans were independently associated with microalbuminuria in nondiabetic hepatitis C patients. CONCLUSION: Hepatitis C infection is independently associated with microalbuminuria but not the metabolic syndrome. Older age and African Americans are strongly associated with microalbuminuria in nondiabetic hepatitis C subjects. More research is needed to explore the implications of these observations.     

Estimating the prevalence of definitive chronic kidney disease in the Japanese general population

Clinical and Experimental Nephrology - Most data on chronic kidney disease (CKD) prevalence has been based on single measurements of renal function and proteinuria. The aim was to determine the...     

Chronic kidney disease in the United States: an underrecognized problem

The continued growth of the population with end-stage renal disease (ESRD) is partially related to the underrecognition of earlier stages of chronic kidney disease (CKD) and risk factors for the development of CKD. There are several published estimates of the prevalence of CKD in the United States. From Third National Health and Nutrition Examination Survey data it has been estimated that there are 6.2 million individuals with serum creatinine levels at or above 1.5 mg/dL, or 8.3 million individuals with decreased glomerular filtration rate (<60 mL/min/1.73 m (2)). Estimates of prevalence from a health maintenance organization study suggest that there are 4.2 million Americans with persistently elevated serum creatinine levels. In addition to the high prevalence, several studies have shown that CKD is associated with increased risk for cardiovascular disease, hospitalizations, and mortality. To promote earlier detection of CKD, The National Kidney Foundation Guidelines for CKD: Evaluation, Classification and Stratification, recommended screening individuals at increased risk for CKD, such as patients with diabetes, high blood pressure, and family history of kidney disease. Therapeutic interventions to delay progression and reduce comorbidity, such as cardiovascular disease, are more likely to be effective if they are implemented early in the course of CKD.     

Association between renal insufficiency and malnutrition in older adults: results from the NHANES III.

BACKGROUND: The extent to which relevant confounding variables influence the recognized association between renal insufficiency and malnutrition is not known. This study examined whether renal insufficiency was associated with malnutrition, independent of relevant demographic, social, and medical conditions in noninstitutionalized adults 60 years of age and older. METHODS: Participants (5248) in the United States Third National Health and Nutrition Examination Survey (NHANES III, 1988 to 1994), a cross-sectional study, were examined in a multivariate logistic regression model. Participants were stratified into three groups of glomerular filtration rate (GFR) by serum creatinine. Dietary and nutritional factors were estimated from 24-hour dietary recall, biochemistry measurements, anthropometry, and bioelectrical impedance. Participants were malnourished if they demonstrated at least three of the following five criteria: (1) serum albumin < or =37 g/L, (2) male weight < or =63.9 kg, female weight < or =51.8 kg, (3) serum cholesterol <4.1 mmol/L, (4) energy intake <15 kcal/kg/day, and (5) protein intake <0.5 g/kg/day. RESULTS: A GFR <30 mL/min/1.73 m(2) was present in 2.3% of men and 2.6% of women; these participants demonstrated low energy and protein intake and higher serum markers of inflammation. Thirty-one percent of individuals with malnutrition demonstrated a GFR <60 mL/min/1.73 m(2). In multivariate analysis, a GFR <30 mL/min/1.73 m(2) was independently associated with malnutrition [odds ratio 3.6 (2.0 to 6.6)] after adjustment for relevant demographic, social and medical conditions. CONCLUSIONS: It is probable that renal insufficiency is an important independent risk factor for malnutrition in older adults. Malnutrition should be considered, prevented, and treated as possible in persons with clinically important renal insufficiency. These results should be confirmed in a prospective longitudinal cohort study.     

The prevalence of chronic kidney disease in the general population in Romania: a study on 60,000 persons

Introduction  

Chronic kidney disease (CKD) is a major public health problem worldwide, due to its epidemic proportions and to its association with high cardiovascular risk. Therefore, screening for CKD is an increasingly important concept, aiming for early detection and prevention of progression and complications of this disease.     

Chronic kidney disease and cardiovascular disease in a general Japanese population: the Hisayama Study

BACKGROUND: Chronic kidney disease has been shown to be an independent risk factor for cardiovascular disease in high-risk populations. However, this relationship is inconclusive in community-based populations. METHODS: To clarify this issue, we followed 2634 community-dwelling individuals without cardiovascular disease, aged 40 years or older, for 12 years and examined the relationship between chronic kidney disease and the incidence of cardiovascular disease. RESULTS: During the follow-up period, 99 subjects (56 men and 43 women) experienced coronary heart disease, 137 subjects (60 men and 77 women) ischemic stroke, and 60 subjects (26 men and 34 women) hemorrhagic stroke. In men, the age-adjusted incidence of coronary heart disease was significantly higher in subjects with chronic kidney disease than in those without it (6.2 vs. 2.9 per 1000 person-years) (P < 0.05), but such a relationship was not observed with ischemic stroke. In contrast, in women, the age-adjusted incidence of ischemic stroke was significantly higher in subjects with chronic kidney disease than in those without it (3.4 vs. 2.5) (P < 0.05), while that of coronary heart disease was not. Chronic kidney disease was not found to be associated with the incidence of hemorrhagic stroke. In multivariate analysis, even after adjustments for traditional and nontraditional cardiovascular disease risk factors, chronic kidney disease was found to be an independent risk factor for the occurrence of coronary heart disease in men [hazard ratio (HR), 2.26; 95% CI, 1.06-4.79], and for the occurrence of ischemic stroke in women (HR, 1.91; 95% CI, 1.15-3.15). CONCLUSION: Our findings suggest that chronic kidney disease is an independent risk factor for the occurrence of cardiovascular disease in the general Japanese population.     

Polycystic kidney disease at end-stage renal disease in the United States: patient characteristics and survival

BACKGROUND: The patient characteristics and mortality associated with autosomal dominant polycystic kidney disease have not been characterized for a national sample of end-stage renal disease (ESRD) patients. METHODS: 375,152 patients in the United States Renal Data System were initiated on ESRD therapy (including patients who eventually received renal transplants) between January 1, 1992 and June 30, 1997 and analyzed in an historical cohort study of polycystic kidney disease. RESULTS: Of the study population, 5,799 (1.5%) had polycystic kidney disease. In logistic regression, polycystic kidney disease was associated with Caucasian race (odds ratio 3.31, 95% CI, 3.09-3.54), women (1.10, 1.04-1.16), receipt of renal transplant (4.15, 3.87-4.45), peritoneal dialysis (vs. hemodialysis, 1.37, 1.27-1.49), younger age, and more recent year of first treatment for ESRD. Use of pre-dialysis EPO but not the level of serum hemoglobin at initiation of ESRD was significantly higher in patients with polycystic kidney disease. Patients with polycystic kidney disease had lower mortality compared to patients with other causes of ESRD, but patients with polycystic kidney disease had a higher adjusted risk of mortality associated with hemodialysis (vs. peritoneal dialysis) compared to patients with other causes of ESRD (hazard ratio 1.40, 1.13-1.75). CONCLUSIONS: Hematocrit at presentation to ESRD was not significantly different in patients with polycystic kidney disease compared with patients with other causes of ESRD. Peritoneal dialysis is a more frequent modality than hemodialysis in patients with polycystic kidney disease, and patients with polycystic kidney disease had an adjusted survival benefit associated with peritoneal dialysis, compared to patients with other causes of renal disease.