[Bicarbonate balance in hemodiafiltration (HDF): a comparison between two infusion methods of on-line prepared solution]. / Bilancio dei bicarbonati in emodiafiltrazione (HDF): confronto fra due metodiche di reinfusione di liquido prodotto on-line.

PURPOSE: Hemodiafiltration (HDF) has high removal rates of low and middle-high molecular weight uremic toxins. We aimed to understand the efficacy and the safety in correcting on-line HDF acidosis. We compared two infusion methods of on-line prepared solution in HDF: HDF with an infusion solution produced from dialysate (HDF-OL) and HDF with a solution from patient ultrafiltrate after regeneration (HFR). METHODS: Eleven patients (four males, seven females) age 66 +/- 10 yrs, dialysis age 5.0 +/- 1.3 yrs, on anuria had two dialysis methods for the 1st session of the week, one HDF-OL and one HFR in 2 different weeks. In HDF-OL a high-flux polysulphone dialyser 1.8 m2 was used, in HFR a two-stage filter was used: polyetersulfone 0.7 m2 + SMC 1.95 m2 and a sorbent cartridge Selecta plus (Bellco) to regenerate the ultrafiltrate. HCO3- in the dialysis bath was 32 mmol/L. RESULTS: Plasma bicarbonates, before dialysis were 21.6 +/- 2.1 mmol/L on HDF-OL and 21.5 +/- 3.3 on HFR (p=ns), at the end they were 27.5 +/- 1.8 mmol/L on HDF-OL and 27.8 +/- 1.2 mmol/L on HFR (p=ns). On HDF-OL bicarbonates reached a plateau at mid session: 27 +/- 1.2, 27.5 +/- 1.2, 27.5 +/- 1.8 to 120, 180 and 240 min respectively. On HFR the plateau was reached more slowly: 26.1 +/- 1.9, 27.1 +/- 1.4, 27.8 +/- 1.2 with the same times. CONCLUSIONS: HFR-OL and HFR efficaciously corrected acidosis in a 4-h dialysis session. The same results, statistically and clinically, were achieved with infusion solution derived from dialysate and from solution from regenerated ultrafiltrate. In the latter, it was interesting that the global quality of the infusion solution was obtained from a close circuit from the patient ultrafiltrate.

Effect of calcium supplementation as a high-calcium mineral water on bone loss in early postmenopausal women.

It is generally agreed that an adequate calcium intake is necessary for the maintenance of bone health and that calcium supplementation reduces the rate of bone loss in postmenopausal women. Mineral waters are calorie free, and some, with relatively high calcium levels, might be significant sources of calcium. We studied the effect of mineral water in 45 early postmenopausal women randomly assigned to receive a high-calcium (Ferrarelle, Italy) or a low-calcium mineral water. On the basis of the dietary regimen, women were divided in two clusters (A = 23 subjects, B = 22 subjects) significantly different only for calcium intake (CI) and for dietary consumption of calories (energy). At the end of the study period (13 +/- 1 months), bone mineral density at the distal radius showed a significant decrease (P < 0.001) only in cluster with low CI. The difference between the clusters was significant (P < 0.05). Furthermore, the cluster with high CI showed a significant (P < 0.05) reduction in osteocalcin serum levels after 3 months. This study provides further evidence to support the use of a high calcium mineral water as an effective prophylaxis against postmenopausal bone loss.

Ultrasonographic assessment of bone in normal Italian males and females.

Recently ultrasound techniques have been proposed to evaluate skeletal status. Speed of sound and attenuation through the bone are the ultrasound properties currently used to assess bone strength and fragility. The speed of sound in m s-1 (SOS), broadband ultrasound attenuation in dB MHz-1 (BUA) and stiffness (S) in 134 healthy females (age range 10-90 years) and in 100 healthy males (age range 10-93 years) was measured using the Achilles scanner (Lunar Corp., Madison, WI, USA). A polynomial function was applied to the observed data to evaluate a pattern of age-related BUA, SOS and S changes. Peak values of SOS, BUA and S were reached in both sexes at the age of 30 years. Average decreases of 12.9% in BUA, 4.9% in SOS and 28.9% in S were found in men aged between 30 and 90 years. In women average decreases of 17.2% in BUA, 4.2% in SOS and 31.9% in S were discovered in those aged between 30 and 90 years. The analysis of SOS, BUA and S changes between pre- and post-menopausal women revealed a significant decrease of these parameters with years since menopause. These data indicate an age-related decrease of ultrasound signals in both sexes. Furthermore, this technique is able to detect, in females, menopause related changes due to oestrogen failure. In contrast, in males, the age-related loss of ultrasound signals appears to be more linear.