Mirjana Fuček

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 Dubočac. 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.

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.

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.

Adiponectin is Not Associated With Blood Pressure in Normotensives and Untreated Hypertensives With Normal Kidney Function

AbstractThe 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 (&bgr; = −0.040; P = 0.43) or diastolic BP (&bgr; = 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.

NEGATIVE TREND IN ASSOCIATION OF UROMODULIN WITH BLOOD PRESSURE IN PREHYPERTENSIVES AND UNTREATED HYPERTENSIVES WITH NORMAL KIDNEY FUNCTION

Objective: Uromodulin and minor G allele UMOD gene rs13333226 have been associated with blood pressure (BP), hypertension (HT) and better renal function. Our aim was to analyze the association of uromodulin and the frequency of G allele with BP and kidney function in untreated subjects with a normal glomerular filtration rate (GFR). Design and method: From 894 participants of the ENAH follow up, a cohort group of 559 untreated subjects (men 55.8 %, cohort group mean age 38.6) with an eGFR > 60 ml/min/1.73m2 (CKD Epi equation) were enrolled into the study. Subjects were divided in three subgroups: optimal BP (OBP; N = 107), prehypertension (PHT; N = 145) and HT (N = 307). UMOD genotyping rs12917707polymorphism was performed by RT-PCR with the fluorescence-based TaqMan system, while urinary uromodulin levels were measured by Enzyme Linked Immunosorbent Assay (ELISA). Results: We failed to find difference in uromodulin levels among BP categories. However, a negative association of uromodulin with systolic BP (NS) and diastolic BP (r = 0.20; p = 0,069) was observed in the entire group. No association between uromodulin and eGFR was noted. Uromodulin was found to be lower in women than men. The frequency of A and G alleles was 83.2% and 16.8%, respectively. No difference in the frequency of G allele was found among the BP categories. A trend of higher uromodulin was observed in homozygous for the G allele. No significant trend was observed between uromodulin and eGFR in the entire group. Conclusions: There is trend of negative association of uromodulin with BP in middle-aged untreated subjects with normal kidney function. We did not find an association of uromodulin with eGFR. A trend of a higher uromodulin urine concentration was observed in subjects with the G allele of UMOD rs13333226.

FIXED DOSE COMBINATION THERAPY IS ASSOCIATED WITH BETTER BLOOD PRESSURE CONTROL AND LOWER ALBUMINURIA IN REAL-LIFE COHORT DURING 7 YEARS OF FOLLOW UP. ENAH – CROATIAN RURAL STUDY

Objective: The aim of this study was to analyze differences in blood pressure (BP) control and albuminuria between subjects treated with fixed dose combination (FCD) and those treated with free components in real-life during the 7 years follow up period. Design and method: Out of 1134 subjects (door-to-door enrollment, participation rate 80%) data on 236 (54 men; 182 women; mena age 63.2 years) treated hypertensives (HT) were analyzed at the end of 7 years of follow-up. At enter 136 of them were already treated HT (group A) and 100 were new-diagnosed HT (group B) who had started with antihypertensive therapy from that moment. Local GP were allowed to tailor antihypertensive therapy during the follow up period. At basal and at the end of follow up BP was measured by physicians who were project collaborators (ESH/ESC guidelines; OmronM6); salt intake (spot urine - Kawasaki equation), eGFR (CKD-Epi) and albumin-to-creatinin ration (ACR mg/g;first morning urine sample) were analyzed in central lab. Pregnant women, terminal ill, bed-ridden patients, those with severe disability, mentally ill or suffering from dementia or at least one limb amputated/immobilized were exclided. Results: At the end of follow up BP controll was achieved in 31.6% and 38% of HT (group A and B, respectively). In both groups, there there were no significnat differences in salt intake, BMI, smoking and the number of used drugs between controlled and uncontrolled subjects (p < 0.05). However, in group A significant increase in FDC prescription was observed ih the controlled vs.uncontrolled subjects (22% vs. 5.5%). BP control was associated with lower ACR in group A (14.9 vs.76.3; p < 0.01) and group B (9.1 vs.24.9; p < 0.05). Conclusions: In this real-life cohort after 7 years of follow-up BP controll was ahived with more drugs but only if used as FDC what was associated with better organoprotection i.e.lower ACR. Overall poor BP control and organoprotection could be improved using more FDC.

[PP.30.29] PREHYPERTENSION AND SINGLE NUCLEOTIDE POLYMORPHISM RS13333226 OF THE UROMODULIN (UMOD) GENE

Objective: Single nucleotide polymorphism of UMOD gene rs13333226 and its G minor allele were found to be associated with lower blood pressure (BP) values. The aim in this study was to analyze the relationship of this polymorphism with prehypertension (PHT) in general population and here we are reporting preliminary cross-sectional results. Design and method: Out of 3056 subjects enrolled in ENAH study, 496 were eligible for further analysis. Exclusion criteria were treatment with antihypertensive drugs, diabetes, pregnancy, eGFR<60 ml/min, cardiovascular or cerebrovascular incident, chronic terminal diseases, dementia, immobility and missing data. BP and heart rate were measured using Omron 6 device following the ESH guidelines. PHT was defined following the JNC 7 guidelines as a BP >=120/80 and <140/90 mmHg, and normotension (NT) as a BP <120/80 mmHg. Clinical and laboratory data were obtained by routine methods and polymorphism was obtained with TaqMan® real time PCR method. Results: Prevalence of genotypes and G minor allele in overall population were A/A 68.5% (N = 340), A/G 29.6% (N = 147), G/G 1,8% (N = 9) and G minor allele 16% (N = 165). Distribution of all genotypes and G minor allele did not differ significantly between groups of participants with PHT and NT. Logistic regression showed that none of the observed genotypes were predictors for PHT. Common risk factors such as gender, age and body mass index affect systolic BP and the estimated glomerular filtration in all genotypes equally. Conclusions: We failed to find neither an association of uromodulin gene (SNP rs13333226) with BP in normotensive subjects nor this SNP was predictor of prehypertension. In this ongoing study we will enlarge the sample what might enable us to detect small changes in BP phenotype, and in follow up period will analyze predictive value of this polymorphisms for development of sustained hypertension.

[OP.7B.06] METABOLIC SYNDROME IN EUROPEAN RURAL POPULATION- DATA FROM THE BRISGHELLA HEART STUDY (ITALY) AND ENAH STUDY (CROATIA).

Objective: Prevalence and characteristics of metabolic syndrome (MS) differ among various populations worldwide. This might explain the observed divergences in association of MS with cardiovascular (CV) and chronic kidney disease (CKD) outcomes. Our aim was to analyze differences in MS between two rural continental populations from South Europe (Italy and Croatia) and its association with CKD and hypertension (HT). Design and method: In this international prospective long-term follow up study data on 5162 subjects from BrEna cohort formed from original cohorts of Brisighella Heart Study (Italy) and ENAH study (Croatia) were analyzed. Out of them 1839 subjects (796 m, 1043 w) were eligible for further analyses, 848 from Croatian and 991 from Italian cohort. NCEP ATP III definition was used for MS diagnosis, CKD was defined as eGFR < 60 ml/min, and HT as BP > = 140/90 mmHg and/or taking antihypertensive drugs. Results: Overall prevalence of MS in the whole group was 32% without differences between Croatian and Italian subgroups (32.8% vs. 31.4%; p = 0.55). In Croatian group MS was more frequently present in women (35.7% vs. 27.2%; p = 0.01), while this was not found in Italian group (32.8% vs. 30.0%). Significant differences were observed in prevalence of pathological values of fasting blood glucose, triglycerides, HDL-cholesterol, waist circumference and blood pressure (52.2 vs. 40.2; 71.9 vs. 64.3; 34.2 vs. 69.9; 93.2 vs. 72.0; 89.9 vs. 95.8, respectively, all p < 0.05). We failed to observe difference in the number (3,4 or 5) of diagnostic elements for MS between the two groups (p > 0.05). There was no difference in prevalence of HT (84.9 vs. 86.3%, p = 0.62). However, CKD was significantly more prevalent in Italian cohort (23.5% vs. 20.5%; p = 0.001). HT was significantly more prevalent in MS than in non-MS group, while we failed to find difference in CKD. Conclusions: Although prevalence of MS was the same in two European rural region, significant differences in characteristics of MS were observed between Croatian and Italian subgroups. Observed differences could be explained more with lifestyle and tradition than genetic variations. Characteristics of MS should be separately analyzed in each population and results should be implemented in national programs and strategies for CKD prevention.

[PP.03.11] PREHYPERTENSION IS ASSOCIATED WITH CHRONIC KIDNEY DISEASE IN EUROPEAN RURAL POPULATION- DATA FROM BRISGHELA HEART STUDY (ITALY) AND ENAH STUDY (CROATIA)

Objective: Chronic kidney disease (CKD) is a silent global epidemic. Hypertension and diabetes are most important risk factors. As prehypertension (PHT) was associated with increased cardiovascular (CV) and renal risk, our aim was to analyze association of PHT with CKD in European rural continental population. Design and method: In this international prospective long-term follow up study data on 5162 subjects (m 2387) from BrEna cohort formed from original cohorts of Brisighella Heart Study (Italy) and ENAH study (Croatia) were analyzed. Them 3389 (m 1456) were eligible for further analyses, and 1335 (m 541) were followed up for average period of 100 months (IQ84–120); 11.337 person years. CKD was defined as eGFR < 60 ml/min (MDRD), HT as BP > = 140/90 mmHg and/or taking antihypertensive drugs, and PHT according to JNC-7 (PHTJ) and ESH stratification (PHTE). At the end of follow-up there were 236 new-onset CKD patients. Results: Prevalence of PHTJ was 25.8% (m vs. w 28.4vs.23.9%;p < 0.05), PHTE 7.8% (m vs.w 8.5vs.7.2; p>0.05). Prevalence of CKD in the whole group was 12.1% (m vs. w. 8.1 vs.15.2; p < 0.01). In the whole group prevalence of CKD increases across BP categories from optimal BP, PHTJ, PHTE and HT (3.2 vs.4.8 vs.5.8 vs.17.8, respectively, p < 0.01), as well in men (0.0 vs.3.3. vs. 2.0 vs.11.7, respectively, p < 0.05) and in women (4.1 vs.6.1 vs.8.9 vs.22.5, respectively, p < 0.01). At baseline, in logistic regression adjusted risk (OR) for CKD was not significant comparing PHT vs. NT, and at the end of follow up PHT was not an independent predictor of new-onset CKD even in obese. In the group of new-onset CKD there was no difference in proportion of PHT at start of follow-up. Conclusions: In European rural population prevalence of CKD increases across BP categories. It is higher in PHT than in NT. PHT was not found to be an independent risk factor for new- onset CKD (3a stage) even in subjects with BMI > 30 kg/m2. Longer period of follow-up, as in HUNT study, is needed this association to become evident. Nevertheless, in PHT, particularly obese, it is prudent to monitor kidney function yearly.

[OP.1B.02] SERUM URIC ACID AND BLOOD PRESSURE IN EUROPEAN RURAL POPULATION WITH NORMAL KIDNEY FUNCTION. DATA FROM BRISGHELLA HEART STUDY (ITALY) AND ENAH STUDY (CROATIA)

Objective: An elevated serum uric acid (SUA) was observed in patients with primary hypertension (HT) and prehypertension (PHT). SUA was associated with blood pressure (BP) values in general population starting from childhood, while treatment with xanthine oxidase inhinitors (XOi) proved to decrease BP indicating on causative role of SUA on development of HT. As data for European, particularly rural, population is lacking our aim was to analyze association of SUA with BP in two rural areas in Croatia and Italy. Design and method: In this international prospective long-term follow up study data on 5162 subjects from BrEna cohort formed from original cohorts of Brisighella Heart Study (Italy) and ENAH study (Croatia) were analysed. Out of them 1596 (754 m 842 w) were eligible for further analyses. Subjects treated with antihypertensive drugs and XOi were excluded. There were 139 subjects with PHT (high normal BP). Subjects with diabetes, eGFR <60 ml/min (MDRD equation), XOi and antihypertensive therapy were exluded. Results: Significant trend in SUA was observed across BP categories NT, PHT and HT (276 (IQ 228–330) vs. 294 (IQ 240–342) vs. 307 (IQ252–360) (p for trend <0.001). Significant correlations of SUA with systolic and diastolic BP were observed (r = 0.192; p < 0.001, r = 0.08; p < 0.001). In mulitvariate linear regression analyses SUA was independently associated with systolic BP after adjustment for age, gender, waist circumference, HDL, LDL, TG, eGFR (beta = 0.11 p < 0.001), each increase of 100 umol/l SUA increase systolic BP for 2.8 mmHg. In adjusted multivariate logistic regression analyses SUA was an independent predictor for HT, i.e. subjects in 4th Q of SUA had higher risk for being HT (1.9 [1.2–3.0]), but not for being PHT. Conclusions: In European rural population without CKD and diabetes SUA is associated with BP and is an independent predictor for HT, but not for PHT. Our results are in agreement with vast majority surveys pointing on possible causative role which should be evaluated in prospective study.