Kenan Ates

A population-based survey of Chronic REnal Disease In Turkey—the CREDIT study

Background. Chronic kidney disease (CKD) is a growing health problem worldwide that leads to end-stage kidney failure and cardiovascular complications. We aimed to determine the prevalence of CKD in Turkey, and to evaluate relationships between CKD and cardiovascular risk factors in a population-based survey. Methods. Medical data were collected through home visits and interviews. Serum creatinine, blood glucose, total cholesterol, triglycerides, HDL, LDL and uric acid were determined from 12-h fasting blood samples, and spot urine tests were performed for subjects who gave consent to laboratory evaluation. Results. A total of 10 872 participants were included in the study. The final analysis was performed on 10 748 subjects (mean age 40.5 ± 16.3 years; 55.7% women) and excluded 124 pregnant women. A low glomerular filtration rate (GFR) (< 60 mL/min/1.73 m2) was present in 5.2% of the subjects who were evaluated for GFR, while microalbuminuria and macroalbuminuria were observed in 10.2% and 2% of the subjects, respectively. The presence of CKD was assessed in subjects who gave consent for urinary albumin excretion measurement (n = 8765). The overall prevalence of CKD was 15.7%; it was higher in women than men (18.4% vs. 12.8%, P < 0.001) and increased with increasing age of the subjects. The prevalence of hypertension (32.7% in the general population), diabetes (12.7%), dyslipidaemia (76.3%), obesity (20.1%) and metabolic syndrome (31.3%) was significantly higher in subjects with CKD than subjects without CKD (P < 0.001 for all). Conclusions. The prevalence of CKD in Turkey is 15.7%. Cardiovascular risk factors were significantly more prevalent in CKD patients.

Relationship of ambulatory blood pressure monitoring data to echocardiographic findings in haemodialysis patients

BACKGROUND The present study was performed to assess the value of ambulatory blood pressure monitoring (ABPM) in determining the adequacy of blood pressure (BP) control, and its relationship to echocardiographic findings in haemodialysis (HD) patients. METHODS We studied 40 non-diabetic adult patients who had been on regular HD treatment for a median duration of 43 months. Twenty-four-hour ABPM was performed using a non-invasive ABP monitor (Pressurescan, ERKA). Casual BP (cBP) was defined as the average of two measurements obtained at two HD sessions, one preceding and one following the ABP recordings, and was calculated for both the predialysis and postdialysis phases. Two-dimensional and M-mode echocardiography were performed in each patient to determine interventricular septal thickness (IVS), left ventricular posterior wall thickness (LVPW), left ventricular fractional shortening (FS), and left ventricular mass index (LVMI). RESULTS According to average 24-h BP levels, 50% of the patients had systolic hypertension (HT) (> 139 mmHg), and 72.5% had diastolic HT (> 87 mmHg), while only 25% had been diagnosed as HT by cBP measurements (P < 0.01 and P < 0.0001 respectively). Diurnal variation in BP was not present in about 80% of the patients. Echocardiography was normal in only four patients (10%). LVMI and LV wall thickness were correlated to ABPM data better than to cBP measurements. Using stepwise linear regression analysis, LVMI and IVS were positively correlated with systolic BP load (P < 0.0001 and P = 0.0001 respectively), and LVPW was positively correlated with night-time systolic BP level (P < 0.001). CONCLUSIONS ABPM is necessary to assess the adequacy of BP control, and is well correlated to end-organ damage of HT in HD patients.

Bone mineral density and its correlation with clinical and laboratory factors in chronic peritoneal dialysis patients

The aim of this study was to assess the clinical and laboratory correlations of bone mineral density (BMD) measurements among a large population of patients on chronic peritoneal dialysis (PD). This cross-sectional, multicenter study was carried out in 292 PD patients with a mean age of 56 ± 16 years and mean duration of PD 3.1 ± 2.1 years. Altogether, 129 female and 163 male patients from 24 centers in Canada, Greece, and Turkey were included in the study. BMD findings, obtained by dual-energy X-ray absorptiometry (DEXA) and some other major clinical and laboratory indices of bone mineral deposition as well as uremic osteodystrophy were investigated. In the 292 patients included in the study, the mean lumbar spine T-score was −1.04 ± 1.68, the lumbar spine Z-score was −0.31 ± 1.68, the femoral neck T-score was −1.38 ± 1.39, and the femoral neck Z score was −0.66 ± 1.23. According to the WHO criteria based on lumbar spine T-scores, 19.2% of 292 patients were osteoporotic, 36.3% had osteopenia, and 44.4% had lumbar spine T-scores within the normal range. In the femoral neck area, the prevalence of osteoporosis was slightly higher (26%). The prevalence of osteoporosis was 23.3% in female patients and 16.6% in male patients with no statistically significant difference between the sexes. Agreements of lumbar spine and femoral neck T-scores for the diagnosis of osteoporosis were 66.7% and 27.3% and 83.3% for osteopenia and normal BMD values, respectively. Among the clinical and laboratory parameters we investigated in this study, the body mass index (BMI) (P < 0.001), daily urine output, and urea clearance time × dialysis time/volume (Kt/V) (P < 0.05) were statistically significantly positive and Ca × PO4 had a negative correlation (P < 0.05) with the lumbar spine T scores. Femoral neck T scores were also positively correlated with BMI, daily urine output, and KT/V; and they were negatively correlated with age. Intact parathyroid hormone levels did not correlate with any of the BMD parameters. Femoral neck Z scores were correlated with BMI (P < 0.001), and ionized calcium (P < 0.05) positively and negatively with age, total alkaline phosphatase (P < 0.05), and Ca × P (P < 0.01). The overall prevalence of fractures since the initiation of PD was 10%. Our results indicated that, considering their DEXA-based BMD values, 55% of chronic PD patients have subnormal bone mass—19% within the osteoporotic range and 36% within the osteopenic range. Our findings also indicate that low body weight is the most important risk factor for osteoporosis in chronic PD patients. An insufficient dialysis dose (expressed as KT/V) and older age may also be important risk factors for osteoporosis of PD patients.

Infectious complications after mass disasters: the Marmara earthquake experience.

The Marmara earthquake occurred on 17 August 1999. There were 639 renal victims, of whom 477 needed some form of renal replacement therapy. Although several medical complications have been reported in the literature, there has been no detailed description of infectious complications in patients with crush syndrome after earthquakes. Data from 35 hospitals considering clinical and laboratory findings, as well as infectious complications and the results of microbiological examinations, were analysed. 223 out of 639 (34.9%) patients had infectious complications, which comprised the most frequent medical problem in the renal victims. The patients who suffered from infections had a higher mortality rate than those who did not (p=0.03). Sepsis and wound infection were the main presentation of the infectious complications. 121 (18.9%) patients suffered from sepsis; the mortality rate was higher in these patients (27.3%) than in victims who did not suffer from sepsis (12.4%, p<0.0001). In a multivariate model, sepsis was associated with increased mortality (p=0.0002, odds ratio 2.45, 95% confidence interval 1.52–3.96). 53 (8.2%) and 41 (6.4%) patients had wound and pulmonary infections, respectively. Most of the infections were nosocomial in origin and caused by Gram-negative aerobic bacteria and Staphylococcus spp. Infectious complications are common in renal victims of catastrophic earthquakes and are associated with increased mortality when complicated by sepsis.

Remission of nephrotic syndrome after removal of localized castleman's disease

Renal complications of Castlemans disease are uncommon. Among the various renal disorders, including mesangial proliferative glomerulonephritis, membranous glomerulonephritis, and minimal change disease, nephrotic syndrome attributable to renal amyloidosis is very rarely reported. We report a case of mixed type of localized Castlemans disease complicated with nephrotic syndrome. Renal biopsy was performed. The deposition of AA amyloidosis was shown. After the removal of two mesenteric lymphoid masses, the proteinuria was gradually decreased and disappeared. Renal biopsy was repeated after 14 months, and, despite complete remission of nephrotic syndrome, no regression in amyloid deposition was found.

RECOGNITION OF NEUROCOGNITIVE DYSFUNCTION IN CHRONIC HEMODIALYSIS PATIENTS

We sought to determine the prevalence, recognition, and consequences of mental impairment among chronic hemodialysis patients. We administered the Mini Mental Status Exam (MMSE), a brief validated method for assessing cognitive mental status that is commonly used by clinicians, to 84 patients from our dialysis units. To determine the clinical implications of mental impairment, we obtained Kt/V, albumin, protein catabolic rate, blood pressure, and hematocrit values. We found that 21% of subjects had mild mental impairment (MMSE 18 to 23) and that 11% had moderate-severe mental impairment (MMSE 0 to 17). We found no relationship between MMSE score and years on dialysis, Kt/V value, hematocrit value, or erythropoietin use. On univariate analysis, MMSE score was associated with albumin, protein catabolic rate, inter-dialytic weight gain, number of co-morbid conditions, number of hospitalizations. Outcomes on univariate analysis were further analyzed by multivariate analysis. There was an independent relationship between decrement in MMSE score and lower protein catabolic rate and increased hospitalization number and number of co-morbid conditions. Based on our findings, we recommend that clinicians routinely screen hemodialysis patients for mental impairment and target impaired patients for interventions to improve mental status and associated adverse outcomes.

Renal Doppler ultrasonographic findings in earthquake victims with crush injury.

In the Marmara earthquake, which occurred on August 17, 1999, 639 people had renal complications, and 477 needed hemodialysis treatment because of acute renal failure due to crush injury. Our objective was to use Doppler ultrasonography as a noninvasive procedure to provide renal hemodynamic information.

Phosphorus control in peritoneal dialysis patients

Hyperphosphatemia is independently associated with an increased risk of death among dialysis patients. In this study, we have assessed the status of phosphate control and its clinical and laboratory associations in a large international group of patients on chronic peritoneal dialysis (PD) treatment. This cross-sectional multicenter study was carried out in 24 centers in three different countries (Canada, Greece, and Turkey) among 530 PD patients (235 women, 295 men) with a mean+/-s.d. age of 55+/-16 years and mean duration of PD of 33+/-25 months. Serum calcium (Ca(2+)), ionized Ca(2+), phosphate, intact parathyroid hormone (iPTH), 25-hydroxy vitamin D(3), 1,25-dihydroxy vitamin D(3), total alkaline phosphatase, and bone alkaline phosphatase concentrations were investigated, along with adequacy parameters such as Kt/V, weekly creatinine clearance, and daily urine output. Mean Kt/V was 2.3+/-0.65, weekly creatinine clearance 78.5+/-76.6 l, and daily urine output 550+/-603 ml day(-1). Fifty-five percent of patients had a urine volume of <400 ml day(-1). Mean serum phosphorus level was 4.9+/-1.3 mg per 100 ml, serum Ca(2+) 9.4+/-1.07 mg per 100 ml, iPTH 267+/-356 pg ml(-1), ionized Ca(2+) 1.08+/-0.32 mg per 100 ml, calcium phosphorus (Ca x P) product 39+/-19 mg(2)dl(-2), 25(OH)D(3) 8.3+/-9.3 ng ml(-1), 1,25(OH)(2)D(3) 9.7+/-6.7 pg ml(-1), total alkaline phosphatase 170+/-178 U l(-1), and bone alkaline phosphatase 71+/-108 U l(-1). While 14% of patients were hypophosphatemic, with a serum phosphorus level lower than 3.5 mg per 100 ml, most patients (307 patients, 58%) had a serum phosphate level between 3.5 and 5.5 mg per 100 ml. Serum phosphorus level was 5.5 mg per 100 ml or greater in 28% (149) of patients. Serum Ca(2+) level was > or =9.5 mg per 100 ml in 250 patients (49%), between 8.5 and 9.5 mg per 100 ml in 214 patients (40%), and lower than 8.5 mg per 100 ml in 66 patients (12%). Ca x P product was >55 mg(2)dl(-2) in 136 patients (26%) and lower than 55 mg(2)dl(-2) in 394 patients (74%). Serum phosphorus levels were positively correlated with serum albumin (P<0.027) and iPTH (P=0.001), and negatively correlated with age (P<0.033). Serum phosphorus was also statistically different (P = 0.013) in the older age group (>65 years) compared to younger patients; mean levels were 5.1+/-1.4 and 4.5+/-1.1 mg per 100 ml, respectively, in the two groups. In our study, among 530 PD patients, accepted uremic-normal limits of serum phosphorus control was achieved in 58%, Ca x P in 73%, serum Ca(2+) in 53%, and iPTH levels in 24% of subjects. Our results show that chronic PD, when combined with dietary measures and use of phosphate binders, is associated with satisfactory serum phosphorus control in the majority of patients.

Prevalence, awareness, treatment and control of hypertension in adults with chronic kidney disease in Turkey: results from the CREDIT study.

Background: In the Chronic REnal Disease In Turkey -CREDIT Study, a large populationbased study on 10,748 adults, the prevalence of chronic kidney disease (CKD) and relationship between CKD and other cardiovascular risk factors had been studied. Methods: This report presents the results of CREDIT study on the prevalence, awareness, treatment, and control of hypertension among CKD patients. Results: The prevalence and awareness of hypertension in CREDIT population was 32.7% and 48.6%, respectively. Of the patients with hypertension, 31.5.% were under treatment, and 16.4% had hypertension under control. Prevalence of CKD was 25.3% in patients with hypertension. Among CKD patients (15.7% of the CREDIT study population), 56.3% had hypertension. The prevalence of hypertension was 34.8% at stage 1, 79.8% at stage 3, and 92.3% at stage 5 CKD. Only 13.4% of patients with CKD have optimal blood pressure. Among CKD patients, 61.9% were aware of hypertension, and 44.2% were under treatment. Overall control rate of hypertension in subjects with CKD was 16.3% with the lowest rate at stage 1 (12.3%) and highest rate at stage 4 (40%). The control rate increased to 28.8% for CKD patients under treatment for hypertension. Conclusion: As a conclusion, hypertension is highly prevalent in subjects with CKD in Turkey with suboptimal awareness, treatment, and control rates. Appropriate health strategies should be implicated to improve prevention, early diagnosis, and treatment of hypertension, which is one of the leading causes of CKD.

Serum C-reactive Protein Level Is Associated with Renal Function and It Affects Echocardiographic Cardiovascular Disease in Pre-Dialysis Patients

Background: Relevance of serum CRP for morbidity and mortality in pre-dialysis patients has not been assessed extensively. The aim of this study was to determine the incidence of elevated serum CRP in pre-dialysis patients and to identify the factors that associate with serum CRP. We were also evaluated the effects of serum CRP on cardiovascular disease, anemia, and nutritional markers. Methods: One hundred and eight pre-dialysis patients with a mean creatinine clearance (CrCl) of 30.1 ml/min were included in the study. Data collected from each patient included demographics, co-morbidity, medications, blood pressures, blood biochemistry including serum CRP, renal function, and echocardiography. Results: Serum CRP was elevated (>5 mg/l) in 43 patients (39.8%). There was a negative correlation between serum CRP and CrCl (r = –0.370, p < 0.001). CrCl was the unique independent factor affecting serum CRP. Serum CRP was an independent factor affecting left ventricular mass index, fractional shortening, serum albumin and hematocrit in multivariate analyses. Conclusions: Prevalence of elevated serum CRP in pre-dialysis patients is high. Reduced renal clearance of CRP and/or cytokines may contribute to the inflammatory status. Elevated serum CRP is an important cause of morbidity in pre-dialysis patients.