Carotid atherosclerosis is a predictor of coronary calcification in chronic haemodialysis patients.

BACKGROUND: Coronary artery calcification scores (CACS) calculated by electron beam computed tomography (EBCT) have been correlated with atherosclerotic burden in the non-uraemic population. However, the validity of this test in chronic haemodialysis patients (HD) is currently uncertain. In the present cross-sectional study, associations between carotid atherosclerosis and coronary calcification in HD patients are investigated. METHODS: We studied 79 chronic HD patients (39 male, 40 female; mean age, 45+/-12 years). The mean time on HD was 68+/-54 months (range, 6-187 months). In these patients, we measured serum calcium, phosphorus, total cholesterol, cholesterol subgroups and iPTH levels. EBCT, echocardiography, and high-resolution B-mode carotid Doppler ultrasonography were also performed. RESULTS: Plaque-positive HD patients had significantly higher CACS than plaque-negative patients (851+/-199 vs 428+/-185, mean+/-SE, P = 0.006). Coronary calcification scores were correlated with serum phosphorus (r = 0.37; P = 0.001). Only 8 of the 24 HD patients without coronary calcification had carotid plaques (33%), whereas 34 of the 53 patients with coronary calcification had carotid plaques (64%) (P = 0.015). Carotid plaque scores were correlated with CACS (r = 0.40; P = 0.001). A stepwise linear regression (model r = 0.72; P<0.001) revealed that CACS (log-transformed data of CACS) was associated with age (P<0.001), time on dialysis (P = 0.004), serum phosphorus level (P = 0.016) and carotid plaque scores (P = 0.037). CONCLUSIONS: Atherosclerosis is independently associated with coronary artery calcification and with hyperphosphataemia in chronic HD patients. CACS appeared to be predictive of both coronary atherosclerosis and carotid atherosclerosis.

Angiotensin converting enzyme gene polymorphism and development of post-transplant erythrocytosis.

BACKGROUND: An increased activation of the renin-angiotensin system probably plays a major role in the development of post-transplant erythrocytosis (PTE). It is known that deletion type polymorphism (DD) in the angiotensin converting enzyme (ACE) gene is associated with higher circulating angiotensin II (AII) levels. The aim of this study was to investigate the effect of ACE gene polymorphism on development of PTE. METHODS: 86 PTE patients (male/female: 68/18, mean age: 32 +/- 10 years) and 68 consecutively transplanted non- PTE patients (male/female: 38/30, mean age: 31 +/- 10 years) were included; 140 patients (91%) had been transplanted from living donors; 92 patients (60%) had hypertension. ACE gene polymorphism was determined by polymerase chain reaction (PCR). RESULTS: The mean time to appearance of PTE was 8.8 +/- 7.9 (range of 1-53) months. DD genotype was detected in 65 patients. PTE patients had a higher prevalence of hypertension (70% vs. 46%, p=0.003) and a lower frequency of DD genotype (34% vs. 54%, p=0.014) as compared to non-PTE patients [OR: 2.2 (1.14-4.25, 95% CI)]. PTE developed more frequently in male patients (68/106: 64%) than females (18/48: 38%) (p=0.002). Patients with DD genotype had a significantly longer leading time to PTE in Kaplan-Meier survival analysis with log-rank (136 +/- 15 vs. 92 +/- 13 months, p=0.015). In Cox regression analysis, hypertension (p=0.002) and recipient ACE genotype (p=0.013) were retained as independent variables for predicting PTE development. CONCLUSIONS: PTE develops more frequently in male, hypertensive renal transplant recipients with good allograft function. DD-type ACE gene polymorphism seems to protect against PTE development.

The changes in serum leptin, body fat mass and insulin resistance after renal transplantation.

BACKGROUND: In this prospective-controlled study, we aimed to investigate the effect of changes in insulin resistance and anthropometrical parameters on serum leptin levels (SLL) after renal transplantation (Tx). PATIENTS AND METHODS: Thirty-four patients (M/F: 19/15, mean age: 29 +/- 9 yr) and 30 age and sex-matched healthy controls (C) were included. Body weight, subscapular, suprailiac, periumbilical, biceps and triceps skinfold thicknesses, neck, wrist, hip and waist circumferences, as well as body mass index and body fat mass were measured as anthropometrical parameters. In order to measure the serum glucose, insulin and SLL, blood samples were obtained before and 1 wk, 1 and 6 months after Tx. Homeostasis Model Assessment (HOMA) values were calculated as an index of insulin resistance. RESULTS: Serum leptin levels (SLL) of the patients at pre-Tx were significantly higher than C (21.5 +/- 3.5 vs. 7.8 +/- 0.9 ng/mL, p = 0.002) and decreased at first week after Tx (from 21.5 +/- 3.5 to 8.4 +/- 1.5 ng/mL, p < 0.001). Thereafter, it gradually increased to 12.8 +/- 2.1 ng/mL in the first month and to 14.4 +/- 2.1 ng/mL in the sixth month after Tx. Serum leptin levels at sixth month were significantly higher than C (p = 0.005). Serum insulin and HOMA values changed similar to SLL after Tx. Correlations between SLL and HOMA persisted during the study period [pre-Tx (r: 0.40) and at first (r: 0.38) and sixth (r: 0.47) months]. In linear regression analysis, HOMA and fat mass were found as independent variables for predicting SLL at the sixth month after Tx. CONCLUSION: Serum leptin levels dramatically decreased immediately after Tx and significantly correlated with serum insulin levels and HOMA during the entire study. Increase in SLL at sixth months was probably because of increase in fat mass, insulin resistance and steroid use in renal transplant recipients.

Stimulated salivary flow rate in chronic hemodialysis patients.

BACKGROUND: Reduced salivary flow has been reported in patients undergoing hemodialysis (HD) treatment. Our aim was to investigate the most important factors associated with stimulated salivary flow rate (ssfr) in chronic HD patients. METHODS: Fifty HD patients (27 F, 23 M, mean age 46. 7 +/- 13.2 years) were divided into two groups according to the duration of HD treatment as those receiving HD therapy less than or equal to (group I) or those more than (group II) 24 months. Fasting blood samples were obtained to determine hepatitis B and C serology, and biochemical and hematological parameters before a HD session. After prestimulation with a standard weight paraffin wax, stimulated saliva was collected in the HD patients and control group (23 F, 25 M, mean age 45.7 +/- 19.1 years) and the flow rate was expressed as ml/min. RESULTS: Both HD groups consisted of 25 patients. There was no significant difference between the two HD groups other than serum alkaline phosphatase (ALP) levels and presence of HCV. The ssfr was decreased than controls in both groups (0.8 +/- 0.6 and 0.7 +/- 0.4, respectively, vs. 1.5 +/- 0.5 ml/min) and it did not correlate with any parameter. Smoking had a positive effect on ssfr in all groups. CONCLUSION: Although the salivary flow rate decreased significantly in chronic HD patients, the duration of therapy displayed no effect on the salivary changes in HD patients, but smoking increased ssfr.

Effect of Valsalva Maneuver on QT Dispersion in Hemodialysis Patients.

Increased QT dispersion seems to be related to an increased risk of arrhythmia and sudden death, a common cause of mortality in hemodialysis (HD) patients. Increase in sympathetic tone has been documented in HD patients. In this study, we aimed to investigate the effect of changes in the autonomic tone on QT dispersion (QTd) in HD patients. Twenty HD patients (M/F 13/7; age, mean ±SD, 28 ± 10 years) and 22 age- and sex-matched healthy controls (M/F 12/10; age, 30 ± 10 years) were included. The patients were dialyzed three-times weekly; time on dialysis was 17 ± 8 months. The QT durations were measured from 12 lead surface EKGs and were corrected for RR intervals. Corrected maximum (QTc max) and minimum (QTc min) QT intervals and their difference (QT c d) were recorded. The effect of the Valsalva maneuver in the release phase on QT c intervals and dispersion was assessed. The HD patients had prolonged values compared to controls: QT c d, 59 ± 17 ms versus 35 ± 7 ms, p < 0.001; QT c max, 458 ± 41 ms versus 397 ± 21 ms, p < 0.001; and QT c min, 398 ± 36 ms versus 362 ± 25 ms, p < 0.001. After the Valsalva maneuver no changes were observed in controls: QT c max, 397 ± 21 ms versus 396 ± 22 ms, p = 0.9; QT c min, 362 ± 24 ms versus 358 ± 19 ms, p = 0.5; and QT c d, 35 ± 7 ms versus 38 ± 10 ms, p = 0.15. Whereas, in HD patients all values were significantly shortened: QTc max, 458 ± 41 ms versus 427 ± 35 ms, p = 0.003; QTc min, 398 ± 36 ms versus 379 ± 34 ms, p = 0.04; and QTc d, 59 ± 17 ms versus 48 ± 15 ms, p = 0.01. The decrease in QTmax was more prominent than the decrease in QTmin, hence QT dispersion was significantly decreased after the Valsalva maneuver, but differences from controls were still significant. In conclusion, increased sympathetic activity may have a role in the prolonged QT duration and increased QT dispersion in HD patients.