[Epidemiology of chronic kidney disease in a population: residents in the territory of Umbria "Gubbio - Gualdese"]. / Epidemiologia della malattia renale cronica in una popolazione: i residenti nel territorio umbro "eugubino-gualdese"

The incidence of chronic kidney disease (CKD) has clearly increased in recent years. It is likely to be correlated with the aging population and with the growing association with vascular diseases. In Italy, there are different registers of dialysis and transplantation, providing an excellent means of monitoring patients in substitution treatment. On the contrary, few material is in our possession regarding CKD patients on conservative therapy. Therefore it lacks a necessary mean to implement mechanisms of prevention and programming for a disease that increasingly shows significant social - health consequences.

Short daily hemodialysis: blood pressure control and left ventricular mass reduction in hypertensive hemodialysis patients.

Several retrospective and uncontrolled prospective studies reported blood pressure (BP) normalization and left ventricular mass (LVM) reduction during daily hemodialysis (DHD). Conversely, the burden of these major independent risk factors is only marginally reduced by the initiation of standard thrice-weekly dialysis (SHD), and cardiovascular events still represent the most common cause of death in hemodialysis patients. Therefore, we performed a randomized two-period crossover study to compare the effect of short DHD versus SHD on BP and LVM in hypertensive patients with end-stage renal disease. We studied 12 hypertensive patients who had been stable on SHD treatment for more than 6 months. At the end of 6 months of SHD and 6 months of DHD in a sequence of randomly assigned 24-hour ambulatory BP monitoring, echocardiography and bioimpedance were performed. Throughout the study, patients maintained the same Kt/V. A significant reduction in 24-hour BP during DHD was reported (systolic BP [SBP]: DHD, 128 +/- 11.6 mm Hg; SHD, 148 +/- 19.2 mm Hg; P < 0.01; diastolic BP: DHD, 67 +/- 8.3 mm Hg; SHD, 73 +/- 5.4 mm Hg; P = 0.01). The decrease in BP was accompanied by the withdrawal of antihypertensive therapy in 7 of 8 patients during DHD (P < 0.01). LVM index (LVMI) decreased significantly during DHD (DHD, 120.1 +/- 60.4 g/m(2); SHD, 148.7 +/- 59.7 g/m(2); P = 0.01). Extracellular water (ECW) content decreased from 52.7% +/- 11.4% to 47.6% +/- 7.5% (P = 0.02) and correlated with 24-hour SBP (r = 0.63; P < 0.01) and LVMI (r = 0.66; P < 0.01). In conclusion, this prospective crossover study confirms that DHD allows optimal control of BP, reduction in LVMI, and withdrawal of antihypertensive treatment. These effects seem to be related to reduction in ECW content.

Survival of vascular access during daily and three times a week hemodialysis.

AIM: A major cause of morbidity for hemodialysis patients is vascular access failure and/or occlusion. It is commonly believed that an increased frequency of dialysis sessions, among other factors, might lead to a higher rate of fistula complications. MATERIALS AND METHODS: To evaluate if patients on daily hemodialysis carry a higher risk of vascular access occlusion, we examined the incidence rate of access occlusion and the survival function of native vascular accesses in patients undergoing daily dialysis (DD; n = 24) as compared to patients on standard three times a week hemodialysis (TWD; n = 124). RESULTS: The mean follow-up time was 3.6 years. In the TWD group 42 patients had a first-access closure, whereas only 2 patients out 24 had a similar event in the DD group. The proportion of first-access closure was 33.9% for TWD and 8.3% for DD (p < 0.01). The incidence rate was 9.8 (95% CI: 7.2 -13.2) and 2.2 (95% CI: 0.4 - 7.1) events per 100 patient-years for TWD and DD, respectively. The rate difference was 7.6 (95% CI 3.4 - 11.9) events per 100 patient-years, and the unadjusted risk ratio was 4.5 (95% CI: 1.2 - 16.9; p < 0.01). The mean vascular access survival before closure was 3.3 years in TWD and 3.7 years in DD. Survival curves, obtained considering the first-access closure as the endpoint, showed a significant difference between DD and TWD (log-rank 5.16; p < 0.05). In a Cox-proportional hazard model the relative risk (RR) of vascular-access closure in TWD remained significant (RR = 4.3; 95% CI 1.1 - 18.2) after adjustment for age. CONCLUSION: The results of this observational study, conducted on a limited number of DD patients, suggest that daily dialysis might not have an adverse prognostic significance for access closure.

Left ventricular hypertrophy in daily dialysis.

Cardiac hypertrophy, a well-known independent risk factor for cardiovascular death, is a very frequent complication in ESRD patients. Its frequency tends to be even higher in dialyzed patients due to the fact that the current dialytic treatments are unable to keep under a satisfactory control the various responsible factors and particularly the blood pressure, which is largely the most important. Daily hemodialysis, a more frequent schedule consisting of 6-7 sessions/week lasting 2 or more hours, has definitely proved its superiority in controlling blood pressure and in improving anemia, and thus has the requisites for positively influencing cardiac hypertrophy. In fact, a series of studies, both retrospective and prospective, performed during the last years by our group, have confirmed that this new, more frequent and thus more physiological schedule, is able not only to stop the progression of the cardiac hypertrophy in uremic patients but also to revert toward the normality, in a relatively short time. This appears to be essentially a consequence of the excellent blood pressure control, which in turn derives from the easier control of the true dry weight, achievable with this type of dialytic treatment.