Assessment of Salt, Potassium, and Iodine Intake in the Croatian Adult Population Using 24 h Urinary Collection: The EH-UH 2 Study.

Cardiovascular diseases, which are the leading cause of death in Croatia, are linked to the high prevalence of hypertension. Both are associated with high salt intake, which was determined almost two decades ago when Croatian Action on Salt and Health (CRASH) was launched. The main objective of the present study was to evaluate salt, potassium, and iodine intake using a single 24 h urine sample in a random sample of the adult Croatian population and to analyse trends in salt consumption after the CRASH was intensively started. METHODS: In this study, we analysed data on 1067 adult participants (mean age 57.12 (SD 13.9), men 35%). RESULTS: Mean salt and potassium intakes were 8.6 g/day (IQR 6.2-11.2) and 2.8 g/day (IQR 2.1-3.5), respectively, with a sodium-to-potassium ratio of 2.6 (IQR 1.8-3.3). We detected a decrease of 17.6% (2 g/day less) in salt consumption compared with our previous salt-mapping study. However, only 13.7% and 8.9% met the WHO salt and potassium recommended targets of 5 g/day and 3.5 g/day, respectively. Salt intake was higher, and potassium ingestion was lower, in rural vs. urban regions and in continental vs. Mediterranean parts of Croatia. Moderate to severe iodine insufficiency was determined in only 3% of the adult participants. CONCLUSION: In the last fifteen years, salt consumption has been significantly reduced in the Croatian adult population because of the intensive and broad CRASH program. However, salt intake is still too high, and potassium ingestion is too low. Salt reduction programs are the most cost-effective methods of cardiovascular disease prevention and merit greater consideration by the government and health policy makers.

Should the CKD EPI Equation Be Used for Estimation of the Glomerular Filtration Rate in Obese Subjects?

INTRODUCTION: The pandemic of obesity is strongly related to increase of chronic kidney disease (CKD) prevalence. The currently recommended CKD epidemiology collaboration (CKD EPI) equation has several serious limitations, particularly in obese subjects who have high body surface area (BSA). The aim of our study was to analyze differences in the prevalence of CKD between CKD EPI and de-indexed equations where individual BSA was used. METHODS: In a total of 2,058 subjects (random sample from a general rural population, 29.65% obese), BSA was estimated using DuBois and DuBois and Moesteller equations and included into the de-indexed equations (CKD DBi, CKD Mi). CKD was classified according to the KDIGO guidelines, and glomerular hyperfiltration (GHF) was defined as 95th percentile, according to the gender and age decade. RESULTS: In obese subjects, prevalence of CKD was significantly higher with CKD EPI than with CKD DBi and CKD Mi equations (9.5%, 6.1%, 5.3%, respectively; p < 0.001), while prevalence of GHF was significantly lower (3.8%, 12.3%, 12.8%, respectively; p < 0.001). Opposite results were observed in subjects with a body mass index <25 kg/m2 for CKD (5%, 7.1%, 7.2%; p = 0.07) and GHF prevalence (6.1%, 1%, 0.6%; p < 0.001). DISCUSSION/CONCLUSIONS: The prevalence of CKD is overestimated, and the prevalence of GHF is underestimated in obese subjects using the CKD EPI equation, i.e., the CKD EPI equation is unreliable in one-third of the population. De-indexed equations should be recommended instead of the CKD EPI equation in epidemiological studies until direct measurement of the glomerular filtration rate becomes more available.

CHRONIC KIDNEY DISEASE IN RURAL POPULATION.

The aims of the study were to provide data on chronic kidney disease (CKD) prevalence in rural population and to analyze the association with cardiovascular risk factors and aging. A random sample of 2193 farmers (1333 female (F) and 860 male (M), mean age 50.61±17.12) were enrolled. Questionnaire and clinical examination were conducted. Participants provided a spot urine and fasting blood sample. Estimated glomerular filtration rate (eGFR) was estimated using Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Subjects were classified according to the KDIGO guidelines. The overall prevalence of CKD (eGFR <60 mL/min/1.73 m2) was 8.83% (F vs. M 9.9% vs. 6.3%; p<0.001). Albuminuria (albumin-to-creatinine ratio >30 mg/g) was found in 8.45% (F vs. M p>0.05). Sharp increase in CKD prevalence was found to begin after the sixth decade (29.44% in subjects older than 65 years; F vs. M 30.9% vs. 26.8%; p<0.01). The strongest predictor factors for CKD were age >65 years (OR 22.12), hypertension (OR 6.53), albuminuria (OR 5.71), fasting blood glucose >7 mmol/L (OR 5.49), diabetes (OR 3.07), abdominal obesity (OR 2.05) and non-smoking (OR 0.41). In multivariate analysis, age (OR 1.13), female gender (OR 0.60) and diabetes (OR 1.75) were the independent predictor factors for CKD. In conclusion, CKD prevalence is high in rural population, being higher in women than in men. In both genders, eGFR significantly decreased with aging. Aging is a significant independent predictor of CKD.

Effectiveness of minimum retesting intervals in managing repetitive laboratory testing: experience from a Croatian university hospital.

INTRODUCTION: Inappropriate laboratory retesting can be addressed by implementing minimum retesting intervals (MRI). The aim of our study was to assess the effectiveness of the implemented MRI protocol for inpatients. MATERIALS AND METHODS: Minimum retesting intervals were applied for 53 laboratory tests. The overall reduction of test requests, reduction in charges and reagent cost savings, frequency of MRI alert appearance as well as the rate of MRI acceptance and ignorance were calculated for a one-year period. Reasons for violating the MRI rule, hospital departments that contributed mostly to MRI rule violation, and the frequency of MRI violations between routine and emergency laboratory were evaluated. RESULTS: During the one-year period, 106,780 requests violated the MRI rule, which corresponds to 14.8% of all requests received. 13,843 requests were cancelled, yielding a 1.9% reduction of requested tests. High-volume tests, namely complete blood count, C-reactive protein, alanine aminotransferase, gamma-glutamyltransferase and total bilirubin, accounted for 65% of all generated alerts and had the highest alert ignorance (>85%). The highest cancellation rate was observed for tumor markers and autoimmunity tests, for most being at least 50%. Annual charge reduction was 62,641 EUR while reagent cost savings were 11,408 EUR. Tests performed in the emergency laboratory had a higher alert appearance than the same routine tests. The most common reason for MRI violation was clinical justification based on the patient's condition. Most frequently ignored MRI alerts were in the intensive care unit. CONCLUSION: MRI implementation showed limited effectiveness in reducing testing repetition and achieving financial savings, yet provided the basis for future improvements.

Autovalidation and automation of the postanalytical phase of routine hematology and coagulation analyses in a university hospital laboratory.

BACKGROUND: The need to satisfy high-throughput demands for laboratory tests continues to be a challenge. Therefore, we aimed to automate postanalytical phase in hematology and coagulation laboratory by autovalidation of complete blood count (CBC) and routine coagulation test results (prothrombin time [PT], international normalized ratio [PT-INR], activated partial thromboplastin time [APTT], fibrinogen, antithrombin activity [AT] and thrombin time [TT]). Work efficacy and turnaround time (TAT) before and after implementation of automated solutions will be compared. METHODS: Ordering panels tailored to specific patient populations were implemented. Rerun and reflex testing rules were set in the respective analyzers' software (Coulter DxH Connectivity 1601, Beckman Coulter, FL, USA; AutoAssistant, Siemens Healthcare Diagnostics, Germany), and sample status information was transferred into the laboratory information system. To evaluate if the automation improved TAT and efficacy, data from manually verified results in September and October of 2015 were compared with the corresponding period in 2016 when autovalidation was implemented. RESULTS: Autovalidation rates of 63% for CBC and 65% for routine coagulation test results were achieved. At the TAT of 120 min, the percentage of reported results increased substantially for all analyzed tests, being above 90% for CBC, PT, PT-INR and fibrinogen and 89% for APTT. This output was achieved with three laboratory technicians less compared with the period when the postanalytical phase was not automated. CONCLUSIONS: Automation allowed optimized laboratory workflow for specific patient populations, thereby ensuring standardized results reporting. Autovalidation of test results proved to be an efficient tool for improvement of laboratory work efficacy and TAT.

Reliability of CKD-EPI predictive equation in estimating chronic kidney disease prevalence in the Croatian endemic nephropathy area.

INTRODUCTION: Chronic kidney disease (CKD) is a significant public health problem and it is not possible to precisely predict its progression to terminal renal failure. According to current guidelines, CKD stages are classified based on the estimated glomerular filtration rate (eGFR) and albuminuria. Aims of this study were to determine the reliability of predictive equation in estimation of CKD prevalence in Croatian areas with endemic nephropathy (EN), compare the results with non-endemic areas, and to determine if the prevalence of CKD stages 3-5 was increased in subjects with EN. MATERIALS AND METHODS: A total of 1573 inhabitants of the Croatian Posavina rural area from 6 endemic and 3 non-endemic villages were enrolled. Participants were classified according to the modified criteria of the World Health Organization for EN. Estimated GFR was calculated using Chronic Kidney Disease Epidemiology Collaboration equation (CKD-EPI). RESULTS: The results showed a very high CKD prevalence in the Croatian rural area (19%). CKD prevalence was significantly higher in EN then in non EN villages with the lowest eGFR value in diseased subgroup. CONCLUSIONS: eGFR correlated significantly with the diagnosis of EN. Kidney function assessment using CKD-EPI predictive equation proved to be a good marker in differentiating the study subgroups, remained as one of the diagnostic criteria for EN.

Chronic dietary exposure to aristolochic acid and kidney function in native farmers from a Croatian endemic area and Bosnian immigrants.

BACKGROUND AND OBJECTIVES: Improvements in agricultural practices in Croatia have reduced exposure to consumption of aristolochic acid-contaminated flour and development of endemic (Balkan) nephropathy. Therefore, it was hypothesized that Bosnian immigrants who settled in an endemic area in Croatia 15-30 years ago would be at lower risk of developing endemic nephropathy because of reduced exposure to aristolochic acid. To test this hypothesis, past and present exposure to aristolochic acid, proximal tubule damage as a hallmark of endemic nephropathy, and prevalence of CKD in Bosnian immigrants were analyzed. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In this cross-sectional observational study from 2005 to 2010, 2161 farmers were divided into groups: indigenous inhabitants from endemic nephropathy and nonendemic nephropathy villages and Bosnian immigrants; α-1 microglobulin-to-creatinine ratio >31.5 mg/g and eGFR<60 ml/min per 1.73 m(2) were considered to be abnormal. RESULTS: CKD and proximal tubule damage prevalence was significantly lower in Bosnian immigrants than inhabitants of endemic nephropathy villages (6.9% versus 16.6%; P<0.001; 1.3% versus 7.3%; P=0.003, respectively); 20 years ago, Bosnian immigrants observed fewer Aristolochia clematitis in cultivated fields (41.9% versus 67.8%) and fewer seeds among wheat seeds (6.1% versus 35.6%) and ate more purchased than homemade bread compared with Croatian farmers from endemic nephropathy villages (38.5% versus 14.8%, P<0.001). Both Croatian farmers and Bosnian immigrants observe significantly fewer Aristolochia plants growing in their fields compared with 15-30 years ago. Prior aristolochic acid exposure was associated with proximal tubule damage (odds ratio, 1.64; 95% confidence interval, 1.04 to 2.58; P=0.02), whereas present exposure was not (odds ratio, 1.31; 95% confidence interval, 0.75 to 2.30; P=0.33). Furthermore, immigrant status was an independent negative predictor of proximal tubule damage (odds ratio, 0.40; 95% confidence interval, 0.19 to 0.86; P=0.02). CONCLUSIONS: Bosnian immigrants and autochthonous Croats residing in endemic areas are exposed significantly less to ingestion of aristolochic acid than in the past. The prevalence of endemic nephropathy and its associated urothelial cancers is predicted to decrease over time.

Adiponectin is not associated with blood pressure in normotensives and untreated hypertensives with normal kidney function.

The role of adiponectin in hypertension is still a matter of debate. Obtained conflicting results could be mostly explained with diversity of subjects included in different studies. Our aim was to analyze association of adiponectin with blood pressure (BP) in a group of normotensive and untreated hypertensive subjects. Participants (N=257) were selected from a random sample of 2487 subjects enrolled in an observational cross-sectional study. Subjects with diabetes and chronic kidney diseases were excluded. BP was measured using Omron M6 device following ESH/ESC guidelines. Adiponectin concentration was determined by ELISA. There were no differences in adiponectin values (mg/L) between hypertensives and normotensives (median 9.75; iqr: 7.44-17.88 vs 11.35; iqr: 7.43-12.63; P=0.17). On univariate linear regression adiponectin was not associated with systolic or diastolic BP (P>0.05). Furthermore, multivariate analysis did not show significant contribution of log-transformed adiponectin either to systolic (ß=-0.040; P=0.43) or diastolic BP (ß=0.066; P=0.33). In our group of normotensives and untreated hypertensives with normal kidney function adiponectin was not associated with BP even after adjustment for other risk factors. Our results and conclusions should not be extrapolated to subjects with other characteristics.

Evaluation of diagnostic criteria for endemic nephropathy.

Diagnosis of endemic nephropathy (EN) is based on the combination of several clinical and laboratory criteria. Despite extensive research no specific diagnostic biomarker for EN has yet been identified. The aim of the study was to evaluate the diagnostic significance of the variables previously proposed as diagnostic criteria, but also new ones. After an extended questionnaire, the clinical and laboratory examination population in EN villages was classified according to the modified WHO criteria. The urinary active form of TGF-ß was measured with a bioassay using a cell line which expresses luciferase activity. In the study we used ROC analysis to examine the predictive value of the tested variables. In the study there was no difference in haemoglobin level between the study subgroups. Leucine aminopeptidase (LAP) in urine and active urinary TGF-ß levels were increased in the EN diseased group when compared to other subgroups, but they did not fulfil the statistical criteria needed for differentiating a diseased form from other study subgroups. Both kidney length and parenchima thickness, alfa1-microglobulinuria, and kidney function assessed by MDRD formula were the variables that differentiated the study subgroups well. Based on our results the cut-off value of alfa1-microglobulin for screening should be 23.5 mg/g creatinine instead of 15 mg/g creatinine in the present criteria, and for making a diagnosis of EN 31,5 mg/g creatinine. Persons with a positive family history for EN had a 5.8 times greater risk of developing EN when compared to a negative one. Taken together, the above-mentioned variables should be implemented in new uniform diagnostic criteria for EN.

Could disappearance of endemic (Balkan) nephropathy be expected in forthcoming decades?

BACKGROUND/AIMS: An epidemiological survey of endemic nephropathy (EN) was performed in endemic Croatian areas and the current prevalence was compared to that reported for the same villages several decades ago. METHODS: A total of 2,487 adult farmers from 6 endemic villages and 3 non-endemic villages were enrolled. An extensive epidemiological questionnaire, clinical examination and laboratory analyses of blood and urine were performed. According to the modified WHO criteria, participants were classified into diseased, suspected of having EN, and those at risk of developing EN. RESULTS: The overall prevalence of EN in the Croatian areas was 1.0%, ranging between 0.3 and 2.3% in different villages. Those suspected of having EN amounted to 3.9%. In the endemic villages a decreasing trend in the prevalence of EN was observed comparable to the results obtained in previous surveys. It is interesting to note that no EN patients were recorded in the endemic village of Dubocac. CONCLUSION: The prevalence of EN in the endemic Croatian areas appears to be decreasing. For the first time, we failed to detect any EN patients in a village that was previously considered endemic, which might indicate that EN is diminishing.