Proteinuria in South Asian children: prevalence and determinants

Prevalence of nephropathy in Indian children and youth with type 1 diabetes mellitus

OBJECTIVES

Children with type 1 diabetes (T1D) having diabetic nephropathy (DN) are at increased risk of developing end stage renal disease. The present study aimed to determine the prevalence of DN and its predictors in Indian children and youth with T1D.

METHODS

This cross-sectional study included 319 children and youth (2.6-21 years) with T1D having disease duration of at least 2 years. Demographic data and laboratory findings were obtained using standard questionnaires and protocols. Diagnosis of diabetic nephropathy was based on albuminuria on two occasions within a period of 3 months.

RESULTS

The prevalence of DN in our study subjects was 13.4%. 7.5% subjects were known cases of diabetic nephropathy on treatment with enalapril. Hypertension was found in 14.3% subjects with DN in contrast to 4.1% without DN (p<0.05). Duration of diabetes and estimated glucose disposal rate were the important predictors of DN. Interestingly, of the 43 children with DN, 11.3% (n=8) were under 10 years age.

CONCLUSIONS

We found a high prevalence of DN in children and youth with T1D including in children under the age of 10 years. Early screening and timely intervention are required to retard the disease progression and avoid end stage renal disease.

Can childhood obesity influence later chronic kidney disease?

Childhood overweight and obesity affects more and more children. Whilst associations of childhood overweight with later outcomes such as hypertension, diabetes and cardiovascular disease have been well documented, less is known about the association of childhood overweight and obesity with kidney disease. We review the existing evidence for the association of childhood obesity with markers of childhood and adult kidney disease. Whilst there is some evidence for an association, studies have not been able to distinguish between childhood being a sensitive time to develop later kidney problems, or whether observed associations of childhood obesity with poor outcomes are driven by greater lifelong exposure to obesity.

The First Report on the Frequency of Asymptomatic Proteinuria in Iranian School-aged Children

Background

Proteinuria is a well-known indicator of renal dysfunction. In this study, we evaluated the frequency of proteinuria in a sample of healthy Iranian elementary school students using both dipsticks and urine albumin-to-creatinine ratio (UACR) methods.

Materials and Methods

This cross-sectional study was performed on 478 school students aged 7-9 years who were selected by multistage random cluster sampling from Isfahan city, Iran. A clean midstream first-morning urine sample was obtained from each subject. Urine samples were examined by dipstick method, and accordingly, they were reported as negative; trace; 1+; 2+; 3+; and 4+. UACR was determined in samples with positive dipstick proteinuria (defined as trace or greater).

Results

This study included 478 students (42.8% boys), with mean age of 7.0 ± 0.4 years. Positive dipstick was detected in 124 (25.9%) cases. The frequency of positive dipstick proteinuria was significantly higher in the girls than boys (29.6% vs. 20.9%, respectively; P = 0.04). In cases with a positive dipstick, 10 (2.1%) cases had UACR 30-300 mg/g. The frequency of UACR of 30-300 mg/g was 1.4% and 2.5% in boys and girls, respectively. There was no significant difference in the frequency of UACR 30-300 mg/g in terms of gender (P = 0.4). None of the subjects had UACR above 300 mg/g.

Conclusion

While the frequency of asymptomatic proteinuria varies widely across different studies, we found a higher rate of proteinuria in Iranian children. Cost-effectiveness analyses are needed to justify large screening program for detecting asymptomatic proteinuria, as a cardinal manifestation of kidney disease, in Iranian children.

A Cross-sectional Prospective Study of Asymptomatic Urinary Abnormalities, Blood Pressure, and Body Mass Index in Healthy School Children

Introduction

Screening school children for urinary abnormalities is an inexpensive task but is not commonly undertaken in India. Although debated in western countries, its utility in early diagnosis of kidney disorders has been proved by studies from Asia. We examined the prevalence of asymptomatic urinary abnormalities (AUA), obesity, and hypertension in school children and analyzed data to identify potential risk factors among those detected with such abnormalities.

Methods

Children and adolescents 8 to 18 years of age of either gender, attending 14 public schools in West Bengal, were screened prospectively from July 2013 to July 2016 for detecting asymptomatic urinary abnormalities by a spot urine test using a dipstick. Sociodemographic profile, medical examination (weight, height, and blood pressure), and questionnaire-based data were recorded.

Results

A total of 11,000 children were screened. Of these, data from 9306 children were available for AUA, obesity, and hypertension. The prevalence rate was 7.44% (95% confidence interval [CI] = 6.91%−7.97%) for at least 1 AUA. Isolated hematuria was present in 5.2% (95% CI 4.75%−5.65%), whereas isolated proteinuria was present in 1.9% (95% CI = 1.62%−2.18%). The prevalence of prehypertension was 13.43% (95% CI = 12.74%−14.12%) and that of hypertension and abnormal body mass index was 4.05% (95% CI = 6.43%−7.47%) and 38.67 (95% CI = 37.68%−39.66%) respectively.

Discussion

The prevalence rates of AUA were comparable with those in some Asian countries but higher than in most developed countries. Of children and adolescents 8 to 18 years of age, those 13 to 18 years had significantly more high risk factors such as AUA, hypertension, and obesity.

Chronic kidney disease in disadvantaged populations

The increased burden of chronic kidney disease (CKD) in disadvantaged populations is due to both global factors and population-specific issues. Low socioeconomic status and poor access to care contribute to health care disparities and exacerbate the negative effects of genetic or biological predisposition. Provision of appropriate renal care to these populations requires a two-pronged approach: expanding the reach of dialysis through development of low-cost alternatives that can be practiced in remote locations, and implementation and evaluation of cost-effective prevention strategies. Kidney transplantation should be promoted by expansion of deceased donor transplant programs and use of inexpensive, generic immunosuppressive drugs. The message of World Kidney Day 2015 is that a concerted attack against the diseases that lead to end-stage renal disease, by increasing community outreach, better education, improved economic opportunity, and access to preventive medicine for those at highest risk, could end the unacceptable relationship between CKD and disadvantage in these communities.

Chronic kidney disease in disadvantaged populations

The increased burden of CKD in disadvantaged populations is due to both global factors and population-specific issues. Low socioeconomic status and poor access to care contribute to healthcare disparities and exacerbate the negative effects of genetic or biologic predisposition. Provision of appropriate renal care to these populations requires a two-pronged approach: expanding the reach of dialysis through development of low-cost alternatives that can be practiced in remote locations, and implementation and evaluation of cost-effective prevention strategies. Kidney transplantation should be promoted by expanding both deceased donor transplant programs and the use of inexpensive, generic immunosuppressive drugs. The message of WKD 2015 is that a concerted attack against the diseases that lead to ESRD, by increasing community outreach, better education, improved economic opportunity, and access to preventive medicine for those at highest risk, could end the unacceptable relationship between CKD and disadvantage in these communities.

Chronic kidney disease (CKD) in disadvantaged populations

Twelve March 2015 will mark the 10th anniversary of World Kidney Day (WKD), an initiative of the International Society of Nephrology and the International Federation of Kidney Foundations. Since its inception in 2006, WKD has become the most successful effort ever mounted to raise awareness among decision-makers and the general public about the importance of kidney disease. Each year WKD reminds us that kidney disease is common, harmful and treatable. The focus of WKD 2015 is on chronic kidney disease (CKD) in disadvantaged populations. This article reviews the key links between poverty and CKD and the consequent implications for the prevention of kidney disease and the care of kidney patients in these populations.

The impact of CKD identification in large countries: the burden of illness

Chronic kidney disease (CKD) is becoming a major public health issue worldwide and an important contributor to the overall non-communicable disease burden. It is associated with major serious consequences including increased risk of mortality, end-stage renal disease, accelerated cardiovascular disease (CVD), mineral and bone disease, adverse metabolic and nutritional consequences, infections, reduced cognitive function and increased risk of acute kidney injury. Mortality from CVD is estimated to be at least 8- to 10-fold higher in CKD subjects compared to non-CKD subjects. Estimates from different parts of the world, especially large countries, reveal an increasing incidence and prevalence of CKD. This is partly attributed to the global increasing prevalence of diabetes, hypertension, obesity and CVD. The global economic impact of CKD is tremendous. This calls for the need of a global effort to raise awareness of CKD, to incorporate prevention of CKD progression program in the public health agenda and to implement programs for early screening and detection of CKD, especially in high-risk population so to allow early institution of treatment to prevent further CKD progression. Hopefully, by doing so, we may reduce CKD burden globally over time and, most importantly, improve the health outcomes of patients with CKD.

Screening for CKD in children: a global controversy

This review addresses the relevance of urinary screening for chronic kidney disease (CKD) in children. Ambiguity about screening children exists because of the uncertainty as to whether early detection of renal disorders in childhood will lead to effective interventions and reduction in the number of individuals who subsequently progress to ESRD. A related concern is whether the adoption of urinary screening programs is cost effective. The most common method that is used for screening children for CKD involves the measurement of spot samples of urine for hematuria and or proteinuria. Although mass screening is now well established in Japan, Taiwan, and Korea, there appears to be movement away from mass screening to detect CKD in children and adolescents in North America and Europe. In December 2007, the American Academy of Pediatrics published their latest recommendations, in which no urinalyses were recommended at any age during childhood. The second issue addressed in this review is the reporting of estimated glomerular filtration rates (GFR) in children by clinical laboratories.

Proteinuria and renal disease: prognostic value of urine dipstick testing for leukocytes

Proteinuria is utilized to screen for underlying kidney disease and serves as a marker of disease progression. The aim of this study was to test the hypothesis that patients with proteinuria will have a higher frequency of urine dipstick positive for leukocytes as an index of noninfectious renal inflammation. In this retrospective analysis, 1,099 urine specimens were evaluated from 676 patients. Proteinuria was present in 39% of the samples and leukocyturia in 5.1%. The percentage of urines that were dipstick positive for leukocytes was similar in those specimens with or without proteinuria. However, in patients with proteinuria and concomitant leukocyturia, the mean serum creatinine concentration was higher (P=0.003) and the calculated GFR was lower (P=0.01) compared to those without this additional abnormality. These differences were noted despite similar age, gender distribution, and array of underlying diseases in these two groups. Based on these findings, urine dipstick testing for leukocytes as a primary means of screening otherwise healthy children for serious renal disease is of little value. However, in patients with established proteinuria, a positive dipstick result for leukocytes is a simple means of identifying those with more prominent noninfectious renal inflammation, a process which may promote kidney disease progression. This finding may serve as an early marker of the severity of renal injury, regardless of whether the primary process is glomerular or tubular.