Early detection of chronic kidney disease: results of the PolNef study

Exploring Symptom Clusters in Chinese Patients with Diabetic Kidney Disease: A Network Analysis

Purpose

The research on symptom management in patients with diabetic kidney disease (DKD) has shifted from separate symptoms to symptom clusters and networks recently. This study aimed to evaluate the unpleasant symptoms of DKD patients, and to investigate how these symptom clusters could affect patients.

Methods

408 DKD patients were recruited in this cross-sectional study. The symptoms of DKD patients were measured using the modified Dialysis Symptom Index. Network analysis was employed to evaluate the symptom network and the characteristics of individual nodes, while factor analysis was utilized to identify symptom clusters.

Results

Blurred vision was the most prevalent symptom among DKD patients. The symptoms identified as the most distressing, severe, and frequent were light headache or dizziness, arteriovenous fistula/catheterization pain, and diarrhea, respectively. Five symptom clusters were obtained from factor analysis, and the most central symptom cluster in the entire symptom network was sexual dysfunction.

Conclusion

This study identified five symptom clusters in Chinese DKD patients, with sexual dysfunction emerging as the most central cluster. These findings carry significant clinical implications, underscoring the necessity of assessing symptom clusters and their associations to enhance symptom management in DKD patients. Further research is essential to elucidate the underlying mechanisms of symptoms and to clarify the associations among symptoms in DKD patients across different disease trajectories or treatment modalities.

Is the proximal tubule the focus of tubulointerstitial fibrosis?

Tubulointerstitial fibrosis (TIF), a common end result of almost all progressive chronic kidney diseases (CKD), is also the best predictor of kidney survival. Almost all cells in the kidney are involved in the progression of TIF. Myofibroblasts, the primary producers of extracellular matrix, have previously received a great deal of attention; however, a large body of emerging evidence reveals that proximal tubule (PT) plays a central role in TIF progression. In response to injury, renal tubular epithelial cells (TECs) transform into inflammatory and fibroblastic cells, producing various bioactive molecules that drive interstitial inflammation and fibrosis. Here we reviewed the increasing evidence for the key role of the PT in promoting TIF in tubulointerstitial and glomerular injury and discussed the therapeutic targets and carrier systems involving the PT that holds particular promise for treating patients with fibrotic nephropathy.

High prevalence of chronic kidney disease and its related risk factors in rural areas of Northeast Thailand

In Thailand, chronic kidney disease (CKD) screening was reported in 2009 with an overall prevalence of 17.5% and the highest at 22.2% in the northeastern region. This study aimed to find out CKD prevalence of the Kidney Disease Improving Global Outcomes criteria and their related risk factors in the rural community. A population-based study was conducted in the rural sub-districts of northeastern Thailand. Data of socio-demographic status, lifestyle, underlying diseases, blood pressure, and body mass index were recorded. Blood and urine analysis was conducted along with ultrasonography of kidneys. Specimen collection and analyses were repeated after 3 months, and the factors associated with CKD were studied by logistic regression analysis. A total of 2205 participants with a mean age of 57.8 ± 11.7 years and female predominance (66.7%) completed the study. The prevalence of CKD was 26.8%, i.e., stages 1 (7.3%); stage 2 (9.0%); stage 3a (6.0%); stage 3b (2.8%); stage 4 (1.4%); and stage 5 (0.3%). Hypertension, diabetes mellitus, and renal stones were the major underlying diseases. Only 3.5% of the participants were aware of having CKD. An increase in age, male, unemployment, current smoking, diabetes, hypertension, underweight, anemia, hyperuricemia, and leukocytosis were significantly associated factors with the disease. The study revealed that CKD has developed as a significant public health problem in rural northeastern Thailand and one out of every four people has CKD. Therefore, early interventions are essential for the proper management and prevention of CKD.

Chronic Kidney Disease Prevalence in Patients with Colorectal Cancer Undergoing Surgery

Colorectal cancer (CRC) is a common and mortal disease. Chronic kidney disease (CKD) is the relatively common comorbidity among cancer patients affecting the available therapy and outcomes. However, data on prevalence of CKD in patients with CRC undergoing surgery is limited. The aim of the study was to evaluate the prevalence of CKD in a cohort of 560 consecutive patients with CRC undergoing surgical treatment with curative intent. Neoadjuvant therapy in a form of radiotherapy or radiochemotherapy was administered before the surgery in 67 patients and in 86 patients, respectively. Results: CKD was reported in 10%, diabetes in 25%, and hypertension in 60%, while anemia was reported in 47%. The patients with CKD were more likely to be older and anemic with higher serum CRP, which reflects a general inflammatory state. Relative to patients without this therapy, patients undergoing neoadjuvant radiochemotherapy were older, had significantly lower eGFR and albumin, and higher creatinine, aspartate aminotransferase and INR, before the surgery. All CKD patients, except two, were older than 65 years of age. Conclusions: In order to ensure the best possible outcomes, CKD should be diagnosed and treated appropriately in oncology patients to prevent complications, so they may continue their therapy with the least interruption or discontinuation of treatment.

Metabolite Genome-Wide Association Study for Indoleamine 2,3-Dioxygenase Activity Associated with Chronic Kidney Disease

Chronic kidney disease (CKD) causes progressive damage to kidney function with increased inflammation. This process contributes to complex amino acid changes. Indoleamine 2,3-dioxygenase (IDO) has been proposed as a new biomarker of CKD in previous studies. In our research, we performed a metabolite genome-wide association study (mGWAS) to identify common and rare variants associated with IDO activity in a Korean population. In addition, single-nucleotide polymorphisms (SNPs) selected through mGWAS were further analyzed for associations with the estimated glomerular filtration rate (eGFR) and CKD. A total of seven rare variants achieved the genome-wide significance threshold (p < 1 × 10-8). Among them, four genes (TNFRSF19, LOC105377444, LOC101928535, and FSTL5) associated with IDO activity showed statistically significant associations with eGFR and CKD. Most of these rare variants appeared specifically in an Asian geographic region. Furthermore, 15 common variants associated with IDO activity were detected in this study and five novel genes (RSU1, PDGFD, SNX25, LOC107984031, and UBASH3B) associated with CKD and eGFR were identified. This study discovered several loci for IDO activity via mGWAS and provided insight into the underlying mechanisms of CKD through association analysis with CKD. To the best of our knowledge, this is the first study to suggest a genetic link between IDO activity and CKD through comparative and integrated analysis.

Risk factors associated with albuminuria in Rwanda: results from a STEPS survey

BACKGROUND

Non-communicable diseases (NCDs) are a growing burden which affects every part of the world, including developing countries. Chronic kidney disease (CKD) has varied etiology which can result from or complicate other NCDs such as diabetes and cardiovascular diseases. The growing prevalence of NCDs coupled with the increasing age in most developing countries, has seen a marked increase of CKD in these settings. CKD has been described as "the most neglected NCD" and greatly affects the quality of life of patients. It also places a huge economic burden on societies. However, few epidemiological data exist, particularly in sub-Saharan Africa. Assessment of the prevalence of albuminuria as a marker of kidney damage and CKD progression and its main risk factors was thus needed in Rwanda.

METHODS

This study analyzed data collected during the first STEPwise approach to NCD risk factor Surveillance (STEPS) survey in Rwanda, conducted from 2012 to 2013, to assess the prevalence of albuminuria. A multistage cluster sampling allowed to select a representative sample of the general population. Furthermore, descriptive, as well as univariable analyses and multiple logistic regression were performed to respond to the research question.

RESULTS

This survey brought a representative sample of 6,998 participants, among which 4,384 (62.65%) were female. Median age was 33 years (interquartile range, IQR 26-44), and over three quarters (78.45%) lived in rural areas. The albuminuria prevalence was 105.9 per 1,000 population. Overall, semi-urban and urban residency were associated with lower odds of CKD (odds ratio, OR 0.36, CI 0.23-0.56, p<0.001 and OR 0.34, CI 0.23-0.50, p<0.001, respectively) than rural status. Being married or living with a partner had higher odds (OR 1.44 (CI 1.03-2.02, p=0.031) and OR 1.62 (CI 1.06-2.48, p=0.026), respectively) of CKD than being single. Odds of positive albuminuria were also greater among participants living with human immunodeficiency virus (HIV) (OR 1.64, CI 1.09- 2.47, p=0.018). Gender, age group, smoking status and vegetable consumption, body mass index (BMI) and hypertension were not associated with albuminuria.

CONCLUSION

The albuminuria prevalence was estimated at 105.9 per 1,000 in Rwanda. Rural residence, partnered status and HIV positivity were identified as main risk factors for albuminuria. Increased early screening of albuminuria to prevent CKD among high-risk groups, especially HIV patients, is therefore recommended.

Estimating the causal effect of transient anemia status on renal and cardiovascular outcomes in community-dwelling patients in Japan at the beginning of impaired renal function using marginal structural modeling

Background

Anemia status may be transient. Causal associations between changes in anemia status over time and adverse outcome development are not well characterized in community-dwelling subjects at the beginning of impaired kidney function.

Methods

This retrospective cohort study used annual health checkup and medical and pharmacy claims data from the JMDC between January 2005 and June 2019. Community-dwelling subjects in Japan with a pre-index estimated glomerular filtration rate (eGFR) ≥ 60 mL/min/1.73 m² followed by a subsequent eGFR < 60 mL/min/1.73 m² (index) were included. The composite renal outcome was ≥ 30% eGFR reduction over 3 years from baseline, serum creatinine doubling, progression to chronic dialysis, kidney transplantation, or eGFR < 15 mL/min/1.73 m². The composite cardiovascular outcome was fatal and non-fatal unstable angina, myocardial infarction, heart failure, or cerebrovascular event. Time-dependent anemia risk was evaluated using Breslow’s estimator and marginal structural Cox models (MSM).

Results

In 32,870 included subjects, 1,396 had anemia at baseline. Adverse outcome incidence was higher in the baseline anemic group, but absolute differences in renal and cardiovascular outcomes between groups were diminished after adjusting for baseline characteristics. In MSM, time-dependent anemia status was associated with higher risk of renal (hazard ratio [95% confidence interval]; 2.6 [1.7–3.8]) and cardiovascular (1.6 [1.2–2.2]) outcomes and mortality (2.8 [1.8–4.3]). Absolute differences in survival probabilities were retained over time but were clinically marginal (1.1–2.7% over 6 years).

Conclusions

Even in subjects at the very early stage of impaired kidney function, early detection and treatment of anemia may help reduce the development of negative sequelae.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10157-021-02137-1.

Association of Lower Urinary Tract Symptom Severity with Kidney Function among Community Dwelling Older Men

PURPOSE

Most international practice guidelines recommend screening for chronic kidney disease among older men with lower urinary tract symptoms. However, prior studies supporting these guidelines are insufficient due to incomplete assessments of kidney function and inadequate adjustment for confounding factors.

MATERIALS AND METHODS

We conducted a cross-sectional study among 5,530 American men older than 65 years in the multicenter Osteoporotic Fractures in Men Study. Chronic kidney disease was defined per international guidelines as estimated glomerular filtration rate less than 60 ml/minute/1.73 m2 based on serum creatinine or cystatin C, or urinary albumin-to-creatinine ratio 30 mg/gm or greater. Lower urinary tract symptoms were assessed with the American Urological Association Symptom Index. Associations were estimated using multivariable linear and modified Poisson regression models.

RESULTS

Chronic kidney disease prevalence was 16% among 5,530 men with serum creatinine, 24% among 1,504 men with serum cystatin C and 14% among 1,487 men with urinary albumin-to-creatinine measurements. Lower urinary tract symptoms were not associated with lower estimated glomerular filtration rate based on serum creatinine or cystatin C. Although symptom severity was modestly associated with a higher prevalence of chronic kidney disease in age/site adjusted analyses, confidence intervals were wide and associations using all 3 definitions were not statistically significant after adjustment for important confounders, including cardiovascular disease and analgesic use.

CONCLUSIONS

Lower urinary tract symptoms are not independently associated with multiple measures of kidney dysfunction or prevalence of chronic kidney disease among older community dwelling men. Our results do not support recommendations for kidney function testing among older men with lower urinary tract symptoms.

US Trends in Prevalence of Sleep Problems and Associations with Chronic Kidney Disease and Mortality

BACKGROUND

To better understand the relation between sleep problems and CKD, we examined temporal trends in the prevalence of self-reported sleep problems in adults in the United States and their associations with CKD and all-cause mortality.

METHODS

Using data from 27,365 adult participants in five biannual National Health and Examination Surveys (2005-2006 through 2013-2014), we studied five self-reported sleep problems-trouble sleeping, sleep disorder, nocturia (urinating ≥2 times/night), inadequate sleep (<7 hours/night), and excessive sleep (>9 hours/night)-plus a composite index. We conducted three types of analysis: temporal trends in the prevalence of each sleep measure by CKD status, using model-based standardization; cross-sectional analysis of associations between four CKD measures and each sleep measure, using logistic regression; and survival analysis of the association between each sleep measure and mortality, using Cox regression.

RESULTS

The prevalence of trouble sleeping and sleep disorder increased over the five surveys by 4% and 3%, respectively, whereas the other sleep problems remained relatively stable. All sleep problems, except inadequate sleep, were more common during the study period among adults with CKD than without CKD (40% versus 21% for nocturia; 5% versus 2% for excessive sleep; 30% versus 25% for trouble sleeping; 12% versus 8% for sleep disorder). Both eGFR <30 ml/min per 1.73 m² and albuminuria were positively associated with nocturia and excessive sleep. Excessive sleep and nocturia were also associated with higher mortality (adjusted hazard ratio for >9 versus 7-9 hours/night=1.7; 95% CI, 1.3 to 2.1; and for nocturia=1.2; 95% CI, 1.1 to 1.4).

CONCLUSIONS

The high prevalence of sleep problems among persons with CKD and their associations with mortality suggest their potential importance to clinical practice. Future work could examine the health effects of identifying and treating sleep problems in patients with CKD.

Kidney targeted delivery of asiatic acid using a FITC labeled renal tubular-targeting peptide modified PLGA-PEG system

Chronic kidney disease (CKD) is one of the leading public health problems worldwide and finally progresses to end-stage renal disease. The therapeutic options of CKD are very limited. Thus, development of drug delivery systems specific-targeting to kidney may offer more options. Here we developed an efficient kidney-targeted drug delivery system using a FITC labeled renal tubular-targeting peptide modified PLGA-PEG nanoparticles and investigated the intrarenal distribution and cell-type binding. We found that the modified nanoparticles with an approximate diameter of 200 nm exhibited the highest binding capacity with HK-2 cells and fluorescence and immunohistochemical analysis showed they mainly localized in renal proximal tubules by passing through the basolateral side. Furthermore, these kidney-specific nanoparticles could significantly enhance the therapeutic effects of asiatic acid, an insoluble triterpenoid compound as drug delivery carriers. In conclusion, these results suggest the potential of the peptide modified PLGA-PEG nanoparticles as kidneytargeted drug delivery system to proximal tubular cells in treatment of CKD.

Diagnosis Patterns of CKD and Anemia in the Japanese Population

INTRODUCTION

Although early intervention for chronic kidney disease (CKD) and renal anemia are desirable, these conditions are often asymptomatic during their early stages and may be underdiagnosed.

METHODS

We retrospectively analyzed Japanese administrative claims data for general and hospital populations. The data period for the general and hospital data ranged from January 2011 to December 2016 and from April 2008 to July 2017, respectively. CKD stage was determined by estimated glomerular filtration rate (eGFR). Anemia was defined per Japanese guidelines using hemoglobin (Hb) values. The proportion of patients who had eGFR-defined stages G3-G5 CKD without a CKD diagnosis, and Hb-defined anemia without an anemia diagnosis or treatment records, was estimated.

RESULTS

Among 16,779 (general) and 68,161 (hospital) patients, a high proportion of G3 CKD patients did not have a CKD-related diagnosis (general: G3a, 95.0%; G3b, 68.4%; hospital: G3a, 89.2%; G3b, 67.9%); however, some patients were treated with antihypertensives. Among anemic patients, 75.7% (G3a) and 66.7% (G3b) of the general population, and 56.2% (G3a) and 47.5% (G3b) of the hospital population, did not have an anemia-related diagnosis or treatment. CKD and anemia were more likely to be diagnosed in patients with G4 and G5 CKD.

CONCLUSION

A high proportion of G3 CKD patients did not have a CKD-related diagnosis. Likewise, many anemic patients with G3 CKD did not have an anemia-related diagnosis. Despite the lack of a CKD-related diagnosis, some patients received appropriate treatment (e.g., antihypertensives). Further outreach to CKD and anemia patients at earlier stages may be warranted.

Chronic Kidney Disease in Patients After Liver Transplantation: A Long-Term Retrospective Analysis From 1 Transplantation Center

OBJECTIVE

Liver transplantation (LTx) is the only effective method of treating end-stage insufficiency of the liver. Coexisting chronic kidney disease (CKD) in these patients may worsen the long-term prognosis. The aim of this retrospective, a 1-center, observational study, was to determine the prevalence and predisposing factors of CKD in patients in the long run after LTx.

PATIENTS AND METHOD

Medical records were obtained, and the 130 patients after LTx (with a mean age of 49.3 ± 11.9 years) who completed the 24-month follow-up period were enrolled in the study. CKD was diagnosed in patients with an estimated glomerular filtration rate (eGFR) of less than 60 mL/min/1.73 m² or who had proteinuria for at least 3 months. Results are presented as means with standard deviation.

RESULTS

CKD was found in 17% of the patients before liver transplantation and in 32% and 39% 12 and 24 months after LTx, respectively. The eGFR values before, 12 months after, and 24 months after LTx were 98.6 ± 48.3, 79.1 ± 29.6, and 76.9 ± 21.3 mL/kg/1.73 m², respectively. The prevalence of CKD was lower in transplant patients with an autoimmune disease (25%) compared with viral (52%) and ethanol abuse (47%) liver cirrhosis etiology (chi-square: P = .04; post hoc analyses: autoimmune vs viral; P = .01; autoimmune vs ethanol abuse; P = .07). A significant negative correlation was found between trough blood tacrolimus concentration and eGFR 12 and 24 months after LTx (P < .05).

CONCLUSIONS

The prevalence of CKD in patients after liver transplantation seems to be higher than in the general population. Patients with autoimmune etiology of the liver disease have better renal function than patients with viral or ethanol abuse liver cirrhosis etiology. Treatment with calcineurin inhibitors adversely influences renal function in patients after liver transplantations.

Associations between access to healthcare, environmental quality, and end-stage renal disease survival time: Proportional-hazards models of over 1,000,000 people over 14 years

Prevalence of end-stage renal disease (ESRD) in the US increased by 74% from 2000 to 2013. To investigate the role of the broader environment on ESRD survival time, we evaluated average distance to the nearest hospital by county (as a surrogate for access to healthcare) and the Environmental Quality Index (EQI), an aggregate measure of ambient environmental quality composed of five domains (air, water, land, built, and sociodemographic), at the county level across the US. Associations between average hospital distance, EQI, and survival time for 1,092,281 people diagnosed with ESRD between 2000 and 2013 (age 18+, without changes in county residence) from the US Renal Data System were evaluated using proportional-hazards models adjusting for gender, race, age at first ESRD service date, BMI, alcohol and tobacco use, and rurality. The models compared the average distance to the nearest hospital (<10, 10-20, >20 miles) and overall EQI percentiles [0-5), [5-20), [20-40), [40-60), [60-80), [80-95), and [95-100], where lower percentiles are interpreted as better EQI. In the full, non-stratified model with both distance and EQI, there was increased survival for patients over 20 miles from a hospital compared to those under 10 miles from a hospital (hazard ratio = 1.14, 95% confidence interval = 1.12-1.15) and no consistent direction of association across EQI strata. In the full model stratified by average hospital distance, under 10 miles from a hospital had increased survival in the worst EQI strata (median survival 3.0 vs. 3.5 years for best vs. worst EQI, respectively), however for people over 20 miles from a hospital, median survival was higher in the best (4.2 years) vs worst (3.4 years) EQI. This association held across different rural/urban categories and age groups. These results demonstrate the importance of considering multiple factors when studying ESRD survival and future efforts should consider additional components of the broader environment.

Profile of chronic kidney disease modifiable risk factors in a rural community of south east Nigeria

BACKGROUND

Chronic kidney disease (CKD) is on the increase globally. Prevention of this condition is ideal, however early detection of the disease becomes desirable where the disease process has begun as there are known interventions which can slow the progress to end stage renal disease (ESRD). This study aimed at detecting the profile of some modifiable risk factors for CKD in a cohort of household heads in a rural community with limited resources for managing chronic kidney diseases.

METHODS

The study was conducted in a rural community in southeast Nigeria. One hundred and forty five household heads from randomly selected households were interviewed. Their blood pressures were taken and their urine tested. The data was analyzed using SPSS version 21. Simple frequencies and means were calculated.

RESULTS

A total of 145 house hold heads were enrolled. Their mean age was 45.08 (19.65) years. Forty-seven percent had no prior knowledge of their blood pressure and 31.5% were found to be hypertensive. Only one study participant (1%) had ever had a urinalysis test and proteinuria and glycosuria were found in 50.4 and 27.9% respectively. Most (75%) patronized patent medicine vendors for their primary healthcare while 31.8% had taken herbal mixtures in the past.

CONCLUSION

There are presently many modifiable risk factors for the development of chronic kidney disease in rural communities in south-east Nigeria. Urgent targeted intervention is required to forestall an epidemic of CKD in the near future.

Joint Assessment of Donor and Recipient hTERT Gene Polymorphism Provides Additional Information for Early Kidney Transplantation Outcomes

Background

There are several genes and genetic loci affecting telomere length, including hTERT gene and BICD1 gene as well as polymorphisms within chromosome 18. It has been demonstrated that the age of the donor is a negative factor associated with long-term kidney allograft function, and that post-transplant complications accelerate transplanted organ aging, thus contributing to estimated glomerular filtration rate (eGFR) decreases. The aim of this study was a joint assessment of donors’ and recipients’ hTERT and BICD1 genes as well as chromosome 18 polymorphisms with regard to early kidney transplantation outcomes.

Material/Methods

The study enrolled 74 pairs of Polish Caucasian kidney allograft cadaveric donors (60% male, mean age 45.99±14.62) and recipients (50.0% male, mean age 48.89±13.50). The transplantation procedure (Tx) was performed between 2001 and 2012. All samples were genotyped in duplicate using Real-Time PCR.

Results

This study showed that rs2735940 hTERT CX-TT donor-recipient genotype pair was associated with almost five times higher odds (OR=4.82; 95% CI: 1.32–18; p=0.016) of delayed graft function (DGF), and that rs2735940 hTERT, rs2630578 BICD1, and rs7235755 chromosome 18 polymorphisms combined pairs were not associated with acute rejection (AR).

Conclusions

In conclusion, both the donor’s and the recipient’s rs2735940 hTERT gene polymorphism was associated with early graft function after transplantation. The odds of DGF were almost five times higher for a combination of CX (CT or CC) donor genotype and TT recipient genotype. Joint assessment of donor-recipient genotype pairs provides more information for prediction of early kidney transplantation outcomes.

Chronic kidney disease in Polish elderly population aged 75+: results of the WOBASZ Senior Survey

Purpose

Kidney filtration decreases with age, which results in an increased frequency of chronic kidney disease (CKD) in the elderly population. The purpose of the study was to assess the prevalence and epidemiology of CKD in the Polish elderly population.

Methods

A representative sample of the Polish elderly population, composed of 918 people (F 452, M 466) in the age of ≥75 years, was chosen. All participants had their history, anthropometric measures and biochemical parameters (creatinine, fasting glucose, complete cholesterol) evaluated. CKD was diagnosed when eGFR was <60 ml/min/1.73 m². The comorbidities, anthropometric and social factors connected with the onset of CKD were also analyzed.

Results

The prevalence of CKD in the analyzed population was 26.9% (F 32.0%, M 15.8%), which gives an estimated number of 495,590 (95% CI 396,363–594,817) patients in the study subpopulation. The majority of these people were in the G3A category—70.1%, while the remaining fell under the G3B—25.7%, G4—3.1% and G5—1.1% categories. Disease awareness among the participants was found to be at 17%. Arterial hypertension (AH) was more frequent in people with CKD (91.0 vs. 80.3%, P < 0.001), whereas diabetes mellitus (DM) prevalence was comparable in both CKD and non-CKD groups (11.7 vs. 11.4%, ns). In the examined group, DM had no influence on the frequency of CKD. In contrast, the presence of cardiovascular diseases substantially increased the chances of developing CKD (OR 1.87, P < 0.05).

Conclusion

1. The prevalence of CKD in the Polish elderly population was 26.9%. 2. Awareness of CKD is low. 3. DM, increasing age and AH did not increase the risk of CKD. 4. Coexistence of cardiovascular diseases increased the risk of having CKD.

Renal Dysfunction in Post-Stroke Patients

BACKGROUND

The presence of chronic kidney disease (CKD) is an indicator of a worse long-term prognosis in patients with ischemic stroke (IS). Unfortunately, not much is known about renal function in the population of post-IS subjects. The aim of our study was to assess the prevalence of renal damage and impaired renal function (IRF) in the population of post-IS subjects.

METHODS

This prospective analysis concerned 352 consecutive post-IS survivors hospitalized in Pomeranian stroke centers (Poland) in 2009. In this group estimated glomerular filtration rate (eGFR) according to MDRD (modification of diet in renal diseases) and CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) formulas and urine albumin/creatinine ratio (ACR) were determined.

RESULTS

Among survivors decreased eGFR (<60 mL/min./1.73m2 according to MDRD or CKD-EPI) or ACR≥30mg/g were detected in 40.38% (23.07% Men, 55.32% Women; P<0.01). The highest prevalence of IRF was noted in post-IS subjects with atheromatic and lacunar IS. In multivariate analysis the ACR≥30mg/g was predicted by older age, diabetes mellitus (DM) and physical disability (modified Rankin scale 3-5 pts.). The association with reduced eGFR was proved for sex (female), DM and physical disability.

CONCLUSIONS

CKD is a frequently occurring problem in the group of post-IS subjects, especially after lacunar and atheromatic IS. Post-IS patients, mainly the elderly women, with physical disability and diabetes mellitus, should be regularly screened for CKD. This could reduce the risk of further cardiovascular events and delay the progression of IRF.

Do Patients With End-Stage Chronic Renal Failure Treated With the Use of Hemodialysis Have Healthy Skin? Evaluation of Skin Lesions and Basic Education About Risk Factors for Skin Cancer in This Patient Population

BACKGROUND

Considering the increasing incidence of skin cancers in patients after renal transplantation, evaluation of skin condition in dialysis patients, from whom kidney transplant recipients are recruited, appears to be very important. Particular importance is attached to the identification of such dialysis patients in the population who require dermatologic care before qualifying for transplantation. The objective of this study was to determine the prevalence of skin diseases in the dialysis patient population. Education of the patients regarding risk factors for skin cancer and the need for sun protection was performed.

METHODS

Full dermatologic examination, including dermatoscopy, was performed on a group of 77 dialysis patients (38 women, 39 men) and a control group of 77 healthy people (60 women, 17 men).

RESULTS

Eight hemodialysis patients had healthy skin compared with 33 people from the control group. In the remaining hemodialysis patients, the following skin lesions were observed: 1) inflammatory and allergic skin disorders in 17 patients; 2) bacterial, fungal, and viral infections in 26 patients; 3) benign lesions in 39 patients; 4) malignant skin lesions and precancerous conditions in 4 patients; and 5) other skin changes in 63 patients.

CONCLUSIONS

Skin lesions are common in the dialysis patient population. Only 10% of the examined population had completely healthy skin, compared with 43% of the control group. More than one-half of dialysis patients required dermatologic care compared with one-third of healthy control subjects.

Signs and symptoms of developmental abnormalities of the genitourinary tract

OBJECTIVE

The abnormalities of the genitourinary tract development are the leading cause of chronic kidney disease (CKD) in children. The diagnosis of this disease in Brazil is late and incomplete, which results in increased morbidity and mortality in this age group. Early diagnosis of this condition is the prerogative of generalist pediatricians, and the aim of this study was to review the clinical signs and symptoms associated with developmental abnormalities of the genitourinary tract.

DATA SOURCES

Based on the description of a symbolic clinical case, the authors conducted a non-systematic review of medical literature.

DATA SYNTHESIS

The results suggest that the following data should be used as a warning for early diagnosis of affected children: (a) combined urinary tract abnormalities (chromosomal abnormalities; sequence of malformations [VACTERLand Prune-Belly]; and musculoskeletal, digestive tract, heart, and nervous system malformations); (b) previous history (congenital anomalies of the kidney and urinary tract [CAKUT] in the family, low birth weight, and oligoamnios); (c) clinical signs (polyuria/nocturia, urinary tract infection, systemic arterial hypertension, failure to thrive, weak urinary stream, difficulty to start urination, distended bladder, non-monosymptomatic enuresis, urinary/urge incontinence, and bowel and bladder dysfunction); and (d) pre- and postnatal ultrasonographic alterations (increased anteroposterior diameter of the renal pelvis, mainly in the third trimester of pregnancy; single kidney; hydronephrosis associated with other abnormalities; and hydronephrosis with parenchymal involvement in the post-neonatal assessment).

CONCLUSION

The suggestions shown here can help the pediatrician to establish clinical hypotheses for the early diagnosis of developmental abnormalities of the genitourinary tract without resorting to expensive and invasive procedures.

Anthropometric measurements and markers of renal function in adults and older adults

Objective: To determine whether anthropometric indicators are associated with markers of renal function in adults and older adults. Methods: This cross-sectional study included 279 adults and older adults attending eight primary healthcare units in eastern Goiânia, Góias. Sociodemographic, lifestyle, and clinical data were collected using a standard questionnaire. Body mass index was categorized as overweight (≥25 kg/m²) or non-overweight. Waist circumference was classified as normal or high; chronic kidney disease was defined as a glomerular filtration rate below 60 mL/minutes/1.73 m²; micro/macroalbuminuria was defined as an albumin/creatinine ratio above 30 mg/g. The association between anthropometric indicators and renal function markers was assessed by multiple linear regression analysis. Results: Chronic kidney disease was present in 8.9% and micro/macroalbuminuria in 34.8% of the sample. The prevalence of overweight was 57.0%. Waist circumference and body mass index were positively associated with glomerular filtration rate, characterized as glomerular hyperfiltration. Microalbuminuria was positively associated with body mass index in women. Conclusion: The prevalences of chronic kidney disease and overweight were high in the study population. Overweight was positively associated with glomerular filtration rate.

Microvascular Complications and Prevalence of Nocturia in Japanese Patients With Type 2 Diabetes Mellitus: The Dogo Study

OBJECTIVE

To evaluate the association between microvascular complications and nocturia among Japanese patients with type 2 diabetes mellitus.

METHODS

Study subjects were 731 Japanese patients with type 2 diabetes mellitus. A self-administered questionnaire was used to collect information on the variables under study. Study subjects were considered to have nocturia if they answered "once or more" to the question: "How many times do you typically wake up to urinate from sleeping at night until waking in the morning?" Diabetic neuropathy was diagnosed if the patients showed two or more of the following three characteristics: neuropathic symptoms, the absence of the Achilles reflex, or abnormal vibration perception. Diabetic nephropathy was defined as positive when the estimated glomerular filtration rate was <30 mL/min/1.73 m(2) and/or the urine albumin-to-creatinine ratio was ≥34 mg/mmol creatinine. Several ophthalmology specialists were responsible for evaluating diabetic retinopathy. Adjustment was made for sex, age, body mass index, duration of diabetes mellitus, current smoking, current drinking, hypertension, stroke, ischemic heart disease, and glycated hemoglobin.

RESULTS

The prevalence of nocturia was 80.4%. Diabetic retinopathy was independently positively associated with nocturia (adjusted odds ratio 2.39 [95% confidence interval: 1.08-6.11]). In contrast, diabetic nephropathy or diabetic neuropathy was not associated with nocturia.

CONCLUSION

In Japanese patients with type 2 diabetes mellitus, only diabetic retinopathy was independently positively associated with nocturia.

Prevalence of chronic kidney disease in a representative sample of the Polish population: results of the NATPOL 2011 survey

BACKGROUND

Chronic kidney disease (CKD) has been proven to be a major risk factor of cardiovascular disease (CVD). Until now, data on the prevalence of CKD among adults in Poland were limited. The NATPOL 2011 survey is a cross-sectional observational study designed to assess the prevalence and control of CVD risk factors in Poland, and the first study capable of evaluating CKD prevalence in adult Polish citizens.

METHODS

Serum creatinine concentration and the urine albumin-to-creatinine ratio (ACR) were measured in 2413 randomly selected participants (ages 18-79 years) from a national survey study. CKD was diagnosed if the estimated glomerular filtration rate (eGFR) was <60 mL/min/1.73 m(2) or ≥60 mL/min/1.73 m(2) with coexisting albuminuria (ACR ≥ 30 mg/g). Additionally, comorbidities and anthropometric and social factors related to the prevalence of CKD were analysed.

RESULTS

The prevalence of CKD was estimated at 5.8% [95% confidence interval (95% CI) 4.6-7.2] using Chronic Kidney Disease Epidemiology Collaboration formula. The general prevalence was higher when the MDRD was applied [6.2% (95% CI 4.0-7.6)]. An eGFR <60 mL/min/1.73 m(2) was found in 1.9% (95% CI 1.5-2.5) of the studied population. This was accompanied by low awareness of this condition (14.9%). The frequency of albuminuria was estimated at 4.5% (95% CI 3.4-5.9). Diabetes mellitus (DM) and arterial hypertension (AH) were more frequent among respondents with diagnosed CKD compared with those without CKD [18.5 versus 4.5% (P < 0.001) and 67.8 versus 29.0% (P < 0.001) respectively]. DM and AH were, apart from increasing age, the two greatest risk factors of CKD.

CONCLUSION

The estimated prevalence of CKD among adults in Poland is 5.8% (∼1 724 960 patients). Its prevalence was lower than expected. CKD is more frequent in older subjects, smokers and people with comorbidities such as AH and DM.

Assessment of the relationship between selected cardiovascular risk factors and the indices of intima-media thickness and coronary artery calcium score in various stages of chronic kidney disease

Renal diseases pose a growing epidemiological and health problem worldwide. Cardiovascular diseases are the leading cause of deaths among patients with chronic kidney disease. Increased risk of atherosclerosis in these patients results from the occurrence of traditional and non-traditional risk factors. The aim of this study was to assess the relationship between selected risk factors for cardiovascular diseases (age, sex, dyslipidemia, hypertension, etc.), intima-media thickness and coronary artery calcium score in patients with chronic kidney disease stages 2, 3 and 4. This study included 60 patients with chronic kidney disease divided into 3 groups on the basis of disease stage and control group consisting of 20 individuals without diagnosed chronic kidney disease and cardiovascular diseases. Blood analysis and blood pressure measurements were taken. All patients underwent carotid artery ultrasound with the assessment of the intima-media thickness, and heart CT scan in order to assess the index of coronary artery calcification. Logistic regression analysis revealed statistically significant correlation between blood vessels calcification and age--the increase in age by 1 year was associated with the increase in the risk of coronary artery calcification by 6.7 %. The increase in IMT by about 0.1 mm raises the risk of calcification by about 2 %. Second logistic regression model revealed that one-year increase in age was associated with an increase in the risk of intima-media thickening by 6.5 %. Occurrence of hypertension was associated with a ninefold increase in intima-media thickening risk in comparison with patients with normal blood pressure. To sum up, age and hypertension were associated with the growth of IMT in CKD patients, while age and exposure to tobacco smoke were associated with the increase in coronary artery calcium score. The relationship between thickening of IMT and the increase in calcification index in patients was also observed in study group.

Link between retinopathy and nephropathy caused by complications of diabetes mellitus type 2

While the correlation and chronology of appearance of diabetic nephropathy and retinopathy is well known in diabetes mellitus (DM) type 1 patients, in DM type 2 this correlation is less clear. A retrospective study including 917 patients with type 2 diabetes. Diabetic retinopathy (DR) was diagnosed based on fundus photographs taken with a non-mydriatic camera. Diabetic nephropathy (DN) was diagnosed based on urinary albumin concentration in a morning urine sample. Statistical analysis was performed with a seemingly unrelated regression (SUR) model. Our SUR model is statistically significant: the test for "model versus saturated" is 2.20 and its significance level is 0.8205. The model revealed that creatinine and glomerular filtration rate (GFR) have strong influence on albuminuria, while body mass index (BMI) and HbA1c have less significant impact. DR is affected positively by diabetes duration, insulin treatment, glucose levels, and HbA1c, and it is affected negatively by GFR, triglyceride levels, and BMI. The association between DR and DN was statistically significant and had a unidirectional correlation, which can be explained by chronological order; that is, DN precedes DR. The present study indicates that the level of renal impairment is proportional to the level of damage to the eye. Furthermore, such an association has a chronological aspect; the renal injury precedes retinal damage.

Establishing equations to evaluate 24 hour urine protein excretion using routine urinalysis

AIM

It is necessary to screen people at high risk for proteinuria with an economical, reliable and convenient method. The aim of this study is to establish a new approach to predict 24 h urine protein (24 h UP) by routine laboratory assays.

METHODS

Five centres were included and a total of 4211 hospitalized patients were enrolled. All samples were assayed for dipstick protein (DSP), specific gravity (SG), 24 h UP and serum albumin (ALB) simultaneously. 4211 patients were randomly divided into two groups for establishing and testing the equations. Equations were built by multiple log-linear regressions.

RESULTS

(i) DSP is significantly correlated to 24 h UP in a logarithmic pattern; (ii) SG interprets 24 h UP for specific DSP; (iii) Equation 1 = 0.203 × 10(dummy-variable F)  × [100 (SG-1)](-0.470) ; and (iv) Equation 2 = 13.366 × 10(dummy-variable F)  × [100 (SG-1)](-0.547)  × [ALB (g/L)](-1.130) The dummy-variable F had a point-to-point accordance to DSP (detailed in text).

CONCLUSION

Combination of DSP and SG can interpret normal-range proteinuria well, and helped by ALB, their interpretation for macro proteinuria is much improved. It is dependable and economical for routine urinalysis to evaluate pathological proteinuria by equation.

Oral anticoagulant therapy in patients receiving haemodialysis: is it time to abandon it?

Oral anticoagulant (OAC) therapy in haemodialysis patients causes a great deal of controversy. This is because a number of pro- and anticoagulant factors play an important role in end-stage renal failure due to the nature of the disease itself. In these conditions, the pharmacokinetic and pharmacodynamic properties of the OACs used change as well. In the case of the treatment of venous thromboembolism, the only remaining option is OAC treatment according to regimens used for the general population. Prevention of HD vascular access thrombosis with the use of OACs is not very effective and can be dangerous. However, OAC treatment in patients with atrial fibrillation in dialysis population may be associated with an increase in the incidence of stroke and mortality. Doubts should be dispelled by prospective, randomised studies; at the moment, there is no justification for routine use of OACs in the above-mentioned indications. In selected cases of OAC therapy in this group of patients, it is absolutely necessary to control and monitor the applied treatment thoroughly. Indications for the use of OACs in patients with end-stage renal disease, including haemodialysis patients, should be currently limited.

The prevalence of chronic kidney disease and its relation to socioeconomic conditions in an elderly Polish population: results from the national population-based study PolSenior

BACKGROUND

Rapidly progressing ageing of worldwide populations is likely to increase the occurrence of chronic kidney disease (CKD) in the next decades. However, until now little is known about the prevalence of CKD in the Polish elderly population. The aim of this study was to assess the prevalence of CKD and its relation to socioeconomic conditions in the Polish elderly population.

METHODS

A glomerular filtration rate estimated (eGFR) according to the CKD-EPI formula and urine albumin/creatinine ratio were determined in 3797 out of 4979 randomly selected elderly subjects from the national survey study PolSenior. Additionally, some socioeconomic factors related to the prevalence of CKD were also analysed.

RESULTS

The prevalence of CKD in the Polish elderly population was 29.4%. Only 3.2% of elderly subjects with CKD were aware of the disease. CKD was more frequent among urban dwellers, non-smokers, alcohol abstinents and those with low physical activity. Decreased eGFR was more frequent among less educated women, better educated men, blue collar female workers and white collar male workers. Increased albuminuria was associated with low physical activity.

CONCLUSIONS

(i) CKD affects almost one-third of the elderly Polish population. (ii) In Poland elderly subjects with CKD are usually unaware of their kidney disease. (iii) In Polish elderly population, CKD is more frequently present among urban residents, non-smokers, abstainers and less physically active people. (iv) Only in women is higher educational status related to the lower risk of CKD.

Intravenous rt-PA in patients with ischaemic stroke and renal dysfunction

OBJECTIVE

Renal dysfunction (RD) increases risk for ischaemic stroke (IS). The impact of RD on the effects of iv-thrombolysis in the Caucasian population has not been fully determined.

AIMS

To evaluate the associations between RD and the outcome of iv-thrombolysis in Caucasian patients with IS.

METHODS

The observational, multicentre study included 404 patients with IS who were treated with iv-thrombolysis. RD was defined as estimated glomerular filtration rate ≤ 60 ml/min/1.73 m(2). Outcome was assessed with modified Rankin Score at 3 months after the stroke onset.

RESULTS

Medians baseline NIHSS score did not differ between groups of patients with and without RD (12.0 vs. 11.0 pts, p=0.33). Unfavourable outcome was found in 52.1% of patients with and in 41.2% of patients without RD (p=0.05), mortality was higher in patients with RD (29.9% vs. 14.3%, p<0.001), and the presence of haemorrhagic transformation (HT) did not differ between the groups (17.1% vs. 17.1% respectively, p=0.996). A multivariate analysis showed no impact of RD on the unfavourable outcome (OR 0.98; 95%CI 0.88-1.10), mortality (OR 0.92; 95%CI 0.81-1.05) or presence of HT (OR 1.03; 95%CI 0.90-1.18).

CONCLUSIONS

We found no impact of RD on the safety and efficacy of iv-thrombolysis in Caucasian patients with IS.

Albuminuria and hyperhomocysteinemia as cardiovascular risk factors in potentially healthy soldiers: A long-term observation

Background

To assess the relations between albuminuria and selected cardiovascular risk factors.

Material/Methods

The study population comprised 200 apparently healthy soldiers aged 28.8±8.1, observed for 36 months.

Results

Albuminuria was revealed in 9% of the studied group at the beginning of the study and in 12.7% at the end of the observation. Albumins increased from 97.0±61.0 mg/24 hours to 165.0±25.7 mg/24 hours after 36 months of observation. The increase of diastolic blood pressure, body mass, C-reactive protein (CRP), and low-density lipoprotein (LDL) was found in the “albuminuria subgroup” after 3 years of observation. This subgroup also presented significantly higher homocysteine and CRP serum concentrations in comparison with the “non-albuminuria group” in the first phase of the study and after 3 years of follow-up.

Conclusions

Albuminuria was found to be a relatively frequent and persistent abnormality in the studied group. The study demonstrated the relationship between the occurrence and the severity of albuminuria and selected biochemical and demographic cardiovascular risk factors. Determination of albuminuria is a useful, early marker of cardiovascular risk in young male professional soldiers.

Risks of nocturia in patients with chronic kidney disease--do the metabolic syndrome and its components matter?

PURPOSE

We evaluate the risk factors for nocturia in patients with chronic kidney disease, and determine whether the metabolic syndrome and its components aggravate nocturia in these patients.

MATERIALS AND METHODS

We enrolled patients with chronic kidney disease who had regular followup at nephrology clinics, and excluded from study those patients undergoing dialysis, and those with neurogenic bladder or active urinary tract infection. Patients were asked to complete a questionnaire including medical history, clinical parameters and times of nocturnal voids in the last month. Laboratory parameters were checked when the questionnaire was completed. Clinically significant nocturia was defined as voiding 2 or more times per night. The metabolic syndrome was defined according to the ATP III (National Cholesterol Education Program Adult Treatment Panel III) guidelines. Chronic kidney disease was divided into 5 stages (based on National Kidney Foundation guidelines). Multivariate logistic regression was used to evaluate the risk factors for clinically significant nocturia.

RESULTS

A total of 202 men and 234 women were eligible for analysis (mean age 68.4 years). The prevalence rate of clinically significant nocturia in patients with chronic kidney disease was 64.0%. Statistically significant risk factors for clinically significant nocturia were patient age (OR 1.02, 95% CI 1.003-1.04) and chronic kidney disease stage (OR 1.47, 95% CI 1.19-1.81) but not gender. Although 53.9% of our patients with chronic kidney disease had the metabolic syndrome, the metabolic syndrome (adjusted OR 0.96, 95% CI 0.64-1.44) and its components had no significant correlations with clinically significant nocturia.

CONCLUSIONS

Clinically significant nocturia is prevalent in patients with chronic kidney disease, and the severity increased with chronic kidney disease stage and patient age. Contrary to previous reports, the metabolic syndrome did not increase the risk of clinically significant nocturia in patients with chronic kidney disease.

Population screening for chronic kidney disease: a survey involving 38,721 Brazilians

BACKGROUND

It is known that chronic kidney disease (CKD) is continuously increasing all over the world, but the available numbers of affected subjects are mostly collected from renal replacement therapy services and they correspond to individuals with end-stage renal disease. The aim of the present study was to diagnose CKD in its earliest stages in the general population based on detection of proteinuria.

METHODS

In public prevention campaigns, from 2005 to 2010, 38 721 inhabitants were evaluated in the state of Sao Paulo (Brazil). Screening procedures included a dipstick test, blood pressure measurement and application of a medical questionnaire.

RESULTS

In the whole population, urine samples of 37 771 individuals (mean age: 44.59 + 21.70, 55.74% females) were evaluated, 7.3% presented proteinuria (1+ or more) in the screening test and 85.5% of them had no previous knowledge of this urinary abnormality. Those individuals were referred for further clinical evaluation in order to confirm the detected alterations. Considering being diabetic and/or hypertensive as important risk factors for CKD, it was observed that they corresponded to 9.7 and 28.4% of the population screened for proteinuria, respectively. Newly detected cases of possible CKD, diabetes and hypertension corresponded to 6.2, 0.3 and 6.5%, respectively.

CONCLUSIONS

This initiative provided information on proteinuria and possible cases of CKD based on a large sampling of the Brazilian population. Proteinuria was detected in 7.3% of these individuals, and such prevalence is similar to that previously described in developed countries.

High prevalence of risk factors for chronic kidney disease in Balkan endemic nephropathy foci

BACKGROUND/AIMS

The aim of this study was to find out the prevalence of the most frequent risk factors for chronic kidney disease (CKD) and the prevalence of urinary abnormalities in adult inhabitants of three Balkan endemic nephropathy (BEN) villages near Bijeljina, Bosnia and Herzegovina.

METHODS

The survey consisted of an interview, blood pressure measurement, and urine dipstick test for proteinuria, hematuria, and glycosuria.

RESULTS

The study involved 1625 (739 males, aged 51 ± 16 years) subjects: 319 (19.6%) with positive family history for BEN, 585 (36%) with hypertension, 604 (37.2%) above 60 years, 146 (9%) with diabetes, and 566 (34.8%) with none of these risk factors. Proteinuria was present in 6.2-7.1% of the subjects with risk factors for CKD but in 3.4% of those without risk factors. Systolic blood pressure and BEN in brother/sister were found to be significant variables associated with proteinuria, but female gender and history of kidney disease with hematuria.

CONCLUSION

In addition to a family burden for BEN, other risk factors for CKD were highly prevalent in BEN villages of the Bijeljina municipality. The frequency of proteinuria was higher in the at-risk group than in the group without risk factors and increased with the number of risk factors.

Screening of a population at risk of chronic kidney disease: analysis of factors associated with low eGFR and microalbuminuria

BACKGROUND AND OBJECTIVE

Numerous screenings of chronic kidney disease (CKD) have been performed all over the world. This screening study was undertaken with the aim of estimating the prevalence of low glomerular filtration rate (eGFR) and microalbuminuria (MAU) and/or proteinuria in a population at risk for CKD and to detect factors associated with these CKD markers.

MATERIALS AND METHODS

This cross-sectional study included 1617 patients without previously known kidney disease who came for regular check-ups to their general practitioners in 13 Belgrade health centers over a 3-month period. Patients selected were as follows: 1316 with hypertension, 208 with type 2 diabetes, and 93 older than 60 years without hypertension or diabetes. Screening included a questionnaire, blood pressure measurement, single MAU dipstick measurement (Micral-test® strip) and proteinuria and GFR estimation by Modification of Diet in Renal Disease.

RESULTS

MAU was found in 419 (25.9%) patients, proteinuria in 163 (10.1%), and eGFR < 60 mL/min/1.73 m(2) in 370 (22.9%). Multivariate logistic regression analysis revealed that female gender, age, duration of hypertension, and smoking were associated with eGFR. Male gender, hypertension, treatment with angiotensin-converting enzyme inhibitors, proteinuria, and systolic blood pressure were associated with MAU.

CONCLUSIONS

High prevalence of MAU/proteinuria and reduced eGFR were found in high-risk persons for CKD. Besides nonmodifiable, significant modifiable factors for MAU were use of angiotensin-converting enzyme inhibitors and strict regulation of hypertension and the factor for reduced eGFR was smoking.

Nocturia and aging: diagnosis and treatment

Nocturia is a frequently encountered problem in clinical practice and a reason for nephrology consultation. Many studies have clearly shown the negative effect of nocturia on several aspects of health-related quality of life and morbidity. Age-associated physiological, structural, hormonal, and histological changes play an important role in the increasing incidence of nocturia in elderly individuals. Besides urologic conditions, nocturia may also be the initial presenting symptom in chronic kidney disease, as well as other systemic diseases. Therefore, it is essential to understand the complex pathophysiology among these factors to establish a precise diagnosis and appropriate management strategies. This review will provide an overview of the effect of aging on the kidneys and urinary system, the pathophysiology, clinical assessment, and treatment strategies of nocturia, and its effect on health-related quality of life.

Nocturia and snoring: predictive symptoms for obstructive sleep apnea

PURPOSE

Current screening for obstructive sleep apnea (OSA) emphasizes self-reported snoring and other breathing symptoms. Nocturia, a symptom with a precise pathophysiological link to sleep apnea, has not been assessed as a screening tool for this common disorder of sleep respiration. In a large sample of adults presenting to area sleep centers, we aimed to determine the predictive power of nocturia for OSA and compare findings with other markers of OSA commonly used to screen for this disease.

METHODS

This was a retrospective chart review. A consecutive sample of 1,007 adult patients seeking treatment at two sleep centers in New Mexico completed detailed medical and sleep history questionnaires and completed diagnostic polysomnography testing. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of nocturia, snoring, high body mass index, sex, and age for OSA were determined. Hierarchical linear regression determined unique variance contribution to the apnea-hypopnea index, the objective measure of sleep apnea severity.

RESULTS

The results are as follows: sensitivities--snoring, 82.6% and nocturia, 84.8%; specificities--snoring, 43.0% and nocturia, 22.4%; PPVs--snoring, 84.7% and nocturia, 80.6%; and NPVs--snoring, 39.6% and nocturia, 27.9%. With hierarchical linear regression, patient-reported nocturia frequency predicted apnea-hypopnea index (OSA severity) above and beyond body mass index, sex, age, and self-reported snoring (P<0.0001).

CONCLUSIONS

Nocturia appears comparable to snoring as a screening tool for OSA in patients presenting to a sleep medical center. Research in urology and primary care clinics is needed to definitively clarify the use of nocturia as a screening instrument for obstructive sleep apnea.