Vegan-vegetarian diets in pregnancy: danger or panacea? A systematic narrative review.

BACKGROUND: Although vegan-vegetarian diets are increasingly popular, no recent systematic reviews on vegan-vegetarian diets in pregnancy exist. OBJECTIVES: To review the literature on vegan-vegetarian diets and pregnancy outcomes. SEARCH STRATEGY: PubMed, Embase, and the Cochrane library were searched from inception to September 2013 for pregnancy and vegan or vegetarian Medical Subject Headings (MeSH) and free-text terms. SELECTION CRITERIA: Vegan or vegetarian diets in healthy pregnant women. We excluded case reports and papers analysing vegan-vegetarian diets in poverty and malnutrition. Searching, paper selection, and data extraction were performed in duplicate. DATA COLLECTION AND ANALYSIS: The high heterogeneity of the studies led to a narrative review. MAIN RESULTS: We obtained 262 full texts from 2329 references; 22 selected papers reporting maternal-fetal outcomes (13) and dietary deficiencies (nine) met the inclusion criteria. None of the studies reported an increase in severe adverse outcomes or in major malformations, except one report of increased hypospadias in infants of vegetarian mothers. Five studies reported vegetarian mothers had lower birthweight babies, yet two studies reported higher birthweights. The duration of pregnancy was available in six studies and was similar between vegan-vegetarians and omnivores. The nine heterogeneous studies on microelements and vitamins suggest vegan-vegetarian women may be at risk of vitamin B12 and iron deficiencies. AUTHOR'S CONCLUSIONS: The evidence on vegan-vegetarian diets in pregnancy is heterogeneous and scant. The lack of randomised studies prevents us from distinguishing the effects of diet from confounding factors. Within these limits, vegan-vegetarian diets may be considered safe in pregnancy, provided that attention is paid to vitamin and trace element requirements.

[A closed cycle]. / Un ciclo chiuso.

A young girl was admitted to the Renal Unit of our Hospital because of loin pain and mild renal failure with bilateral hydronephrosis. The abdomen ultrasound was very helpful to get the right diagnosis.

[Are convective treatments equivalent to the traditional ones? The Hemo Study and beyond (review)]. / Le terapie convettive equivalgono a quelle tradizionali? Lo studio Hemo ed oltre.

Dialysis treatments have allowed 'terminal patients' to live for years and years. However, life expectancy and quality are still consistently reduced in renal dialysis patients. Consequently, all efforts to device alternative treatments to the conventional ones are highly justified. Recently, the Hemo Study showed that neither the use of high flux membranes, nor the increase of the dialysis dose above the conventional, were capable to reduce significantly patient's mortality and morbidity, although 8% reduction of the risk of death was seen in patients treated with high flux vs. patients treated with low-flux dialysis. A relevant question is if convective treatments may offer an overprotection from morbidity and mortality, in comparison with low flux and high flux treatments. Data from the Registro Lombardo di Nefrologia e Trapianto published in 2000 showed a trend toward a better survival (RR= 90) and a significantly better protection from tunnel carpal syndrome (RR= 0.58; p= 0.03) in patients treated with convective treatments (hemofiltration and/or hemodiafiltration) vs. patients treated with diffusive dialysis. Except than a better cardiovascular stability observed on hemofiltration and an higher beta2-microglobuline clearance given by online hemofiltration and hemodiafiltration, evident clinical benefits of convective treatments, over the conventional high flux treatments, are not yet clearly demonstrated. Notwithstanding that, online convective treatments, that are performed with high flux compatible membranes and high technology machines, producing high quality water, offer at the moment the best bases for the improvement of clinical results of dialysis, especially in some category of patients.

Predilution haemofiltration--the Second Sardinian Multicentre Study: comparisons between haemofiltration and haemodialysis during identical Kt/V and session times in a long-term cross-over study.

BACKGROUND: The potential superiority of various renal replacement treatment modalities consisting largely of convective mass transfer as opposed to primarily diffusive mass transfer, is still a matter of debate. The objective of the present study was to evaluate acute and long-term clinical effects of varying degrees of convection and diffusion in a group of 24 clinically stable patients with end-stage renal disease. METHODS: The patients were prospectively assigned to three consecutive treatment schedules of 6 months each: phase I (HF1) (on-line predilution haemofiltration)-->phase II (HD) (high-flux haemodialysis)-->phase III (HF2; as phase I). We used the AK100/200 ULTRA monitor (Gambro), which prepares ultrapure dialysis fluid for HD and sterile, pyrogen-free substitution solution for HF. The membrane (polyamide), fluid composition, and treatment time were the same on HF and HD. The targeted equilibrated Kt/V was 1.2 for both treatment modes, creating a similar urea clearance. RESULTS: Fifteen patients, mean age 62.8+/-8.4 years, completed the study according to the above conditions. Urea kinetics, nutritional parameters, and dry weight were similar in the three periods. The frequency of intra-treatment episodes of hypotension/patient/month was significantly lower on HF1 (1.24) and HF2 (1.27) than on HD (1.80) (P<0.04). It decreased progressively on HF1, then increased on HD, and decreased again during HF2. Patients had fewer muscular cramps on HF than on HD (P<0.03) and required significantly less saline and plasma expander during HF than HD sessions. The prevalence of inter-treatment symptoms, including fatigue and hypotension, was lower on HF than on HD (score difference P=0.04). Quality of life, determined by the Laupacis method in all three periods, showed a tendency towards improvement during the study, reaching the best values during HF2. CONCLUSIONS: HF has a progressive stabilizing haemodynamic effect, producing a more physiological cardiovascular profile than HD. This long-term effect, observed in stable patients treated under strictly identical conditions, is probably due to the mechanism of convection, and is different from the acute effect observed mainly in unstable patients.

Adequacy in pre-dilution haemofiltration: Kt/V or infusion volume? The Sardinian Collaborative Study Group on Haemofiltration On-line.

Kt/V is the main index of adequacy for diffusive and diffusive convective methods of extracorporeal depuration, yet there exists no universally acceptable validation of an adequacy index for the solely convective methods such as haemofiltration (HF). The aim of the present study is to analyse which of the parameters of adequacy used in two multicentre HF studies, Kt/V for urea or infusion volume, correlate best with nutritional parameters and can therefore be utilized for the evaluation of treatment dose in on-line pre-dilution HF. Twenty-three clinically stable patients were enrolled in the first study [3 months of haemodialysis (HD)+ 3 months of HF]. In the second study, 24 stable patients were studied in three phases: 6 months in HF, 6 months in HD and a further 6 months in HF; in this study, a target of Kt/V= 1.2 in all three periods was preestablished: 15 patients completed the full study. In both studies, we utilized the same monitor (AK 100/200 Ultra, Gambro), the same membrane (polyamide) and the same on-line prepared ultrapure dialysis fluid and sterile infusion solution. In both studies, we ensured that HF fulfilled the following parameters of adequacy: urea kinetics, cardiovascular and blood pressure stability (better in HF than in HD), common haematochemical and nutritional parameters, reduction in beta2-microglobulin levels, a good intra- and extra-session clinical outcome, and a good quality of life with morbidity and mortality rates no different from those of HD. HF proved to be an efficacious method of ensuring adequate depuration and a good quality of life for uraemic patients. We have shown that in longer periods of HF, a notable correlation between Kt/V and normalized protein catabolic rate (nPCR) and an equally good correlation between total ultrafiltration (UF)/dry weight ratio and nPCR could be achieved. In both studies, the patients showed a good level of epuration adequacy when total UF per session was at least 1.3 times the dry body weight. The total UF/body weight ratio thus seems to be an easy method in HF because of its greater ease of predictability and measurement, also when it is used independently of the Kt/V index.

Effect of high-flux dialysis on the anaemia of haemodialysis patients.

BACKGROUND: Anaemia is one of the major clinical characteristics of patients with chronic renal failure, and has a considerable effect on morbidity and mortality. Adequate dialysis is of paramount importance in correcting anaemia by removing small and medium-sized molecules, which may inhibit erythropoiesis. However, high-molecular-weight inhibitors cleared only by means of highly porous membranes have also been found in uraemic serum and it has been claimed from uncontrolled studies that high-flux dialysis could improve anaemia in haemodialysis patients. METHODS: We therefore planned this multicentre randomized controlled trial with the aim of testing whether the use of a large-pore biocompatible membrane for a fixed 12-week follow-up improves anaemia in haemodialysis patients in comparison with the use of a conventional cellulose membrane. Eighty-four (5.3%) of a total of 1576 adult haemodialysed patients attending 13 Dialysis Units fulfilled the entry criteria and were randomly assigned to the experimental treatment (42 patients) or conventional treatment (42 patients). RESULTS: Haemoglobin levels increased non-significantly from 9.5+/-0.8 to 9.8+/-1.3 g/dl (dP=0. 069) in the population as a whole, with no significant difference between the two groups (P:=0.485). Erythropoietin therapy was given to 32/39 patients (82%) in the conventional group, and 26/35 (74%) in the experimental group (P:=0.783) with subcutaneous administration to 26/32 patients in conventional and to 23/26 patients in experimental group, P:=0.495. Dialysis dose (Kt/V) remained constant in both groups (from 1.30+/-0.17 to 1.33+/-0.20 in the conventional group and from 1.28+/-0.26 to 1.26+/-0.21 in the experimental group, P:=0.242). Median pre- and post-dialysis beta(2)-microglobulin levels remained constant in the conventional group (31.9 and 34.1 mg/dl at baseline) and decreased in the experimental group (pre-dialysis values from 31.1 to 24.7 mg/dl, P:=0.004 and post-dialysis values from 24.8 to 20.8 mg/dl, P:=0.002). Median erythropoietin doses were not different at baseline (70 IU/kg/week in conventional treatment and 90 IU/kg/week in experimental treatment, P:=0.628) and remained constant during follow-up (from 70 to 69 IU/kg/week in the conventional group and from 90 to 91 IU/kg/week in the experimental group, P:=0.410). Median erythropoietin plasma levels were in the normal range and remained constant (from 12.1 to 12.9 mU/ml in the conventional group and from 13.2 to 14.0 mU/ml in the experimental group, P:=0.550). CONCLUSIONS: This study showed no difference in haemoglobin level increase between patients treated for 3 months with a high-flux biocompatible membrane in comparison with those treated with a standard membrane. When patients are highly selected, adequately dialysed, and have no iron or vitamin depletion, the effect of a high-flux membrane is much less than might be expected from the results of uncontrolled studies.

On-line predilution hemofiltration versus ultrapure high-flux hemodialysis: a multicenter prospective study in 23 patients. Sardinian Collaborative Study Group of On-Line Hemofiltration.

The aims of the present prospective multicenter study were to assess the clinical tolerance and well being, the correlation between nPCr and Kt/V and the pretreatment beta 2-microglobulin level in patients sequentially treated with high-flux dialysis with ultrapure bicarbonate hemodialysis (HD; phase 1) and predilution hemofiltration (HF) with on-line prepared bicarbonate substitution fluid (phase II). The same monitor (Gambro AK 100 ULTRA) and membrane (polyamide) were used. Twenty-three patients, all in a stable clinical condition, entered the study. The treatment was targeted to an equilibrated Kt/V (eqKt/V) of 1.4 for HD and 1.0 for HF. No mortality or relevant morbidity were observed. The number of hypotensive episodes was 1.78 +/- 2.8 per patient and month during HD vs. 1.17 +/- 3.1 during HF (p = 0.003) and the number of the hypertensive episodes 1.28 +/- 2.8 during HD vs. 0.42 +/- 0.8 during HF (p = 0.04). Incidences of arrhythmia, muscular cramps and headache were significantly less frequent during HF. Interdialytic cramps, arthralgia and fatigue were also significantly less frequent during the HF period. The average beta 2-microglobulin level was 27.1 +/- 14.7 mg/dl at the start of the study, 22.9 +/- 4.9 mg/dl at the beginning of phase II and 22.4 +/- 4 mg/dl at the end of phase II (p = 0.01 compared to the start). A significant linear correlation between the normalized protein catabolic rate and eqKt/V was obtained faster during HD than during HF (45 vs. 120 days) indicating that HF affects the nutritional status with mechanisms different from HD. The present study is in agreement with the hypothesis that HF gives and adequate nutritional status with improved clinical stability and well being at a lower Kt/V compared to HD. Both therapies were efficient in controlling the pretreatment beta 2-microglobulin level.

Mean levels and distribution of some risk factors for atherosclerosis in Sardinia: the ATS-Sardegna Survey.

Six population samples of randomly chosen men and women aged 20-59 years in the four provinces of the island of Sardinia, for a total of 5,697 individuals (overall participation 55%), were examined to determine the mean levels and distribution of some risk factors for atherosclerosis. A remarkable uniformity of such levels, with some minor exceptions, was found throughout the island. The overall, age-standardized mean levels for the factors considered are as follows (men and women, respectively): total cholesterol (TC) (mg/dl) 204 and 196; LDL-cholesterol (LDL-C) (mg/dl) 131 and 125; apolipoprotein B (ApoB) (mg/dl) (five out of six areas) 112 and 104; HDL-cholesterol (HDL-C) (mg/dl) 48 and 53; triglyceride (TG) (mg/dl) 117 and 89; systolic blood pressure (mmHg) 129 and 128; diastolic blood pressure (mmHg) 81 and 80; body mass index (BMI) [kg/(m)2] 26 and 25; prevalence of smokers (%) 48 and 15; cigarettes per day among smokers 19 and 11. A regular increase with increasing age exists for TC, LDL-C, ApoB, blood pressure (systolic and diastolic) and BMI. Compared to the results of a previous survey eight years earlier, an unfavorable trend is in progress, particularly for TC levels in both sexes and smoking among women.