The social cost of chronic kidney disease in Italy

This study aims to estimate the mean annual social cost per patient with chronic kidney disease (CKD) by stages 4 and 5 pre-dialyses and cost components in Italy. The multicenter cross-sectional study included all adult outpatients in charge of the 14 main Nephrology Centers of Tuscany Region during 7 weeks from 2012 to 2013. Direct medical costs have been estimated using tariffs for laboratory tests, diagnostic exams, visits, hospitalization and prices for drugs. Non-medical costs included expenses of low-protein special foods, travel, and formal and informal care. Patients' and caregivers' losses of productivity have been estimated as indirect costs using the human capital approach. Costs have been expressed in Euros (2016). Totals of 279 patients in stage 4 and 205 patients in stage 5 have been enrolled. The estimated mean annual social cost of a patient with CKD were €7422 (±€6255) for stage 4 and €8971 (±€6503) for stage 5 (p < 0.05). Direct medical costs were higher in stage 5 as compared to stage 4; direct non-medical costs and indirect costs accounted, respectively, for 41 and 5 % of the total social cost of CKD stage 4 and for 33 and 9 % of CKD stage 5. In Italy, the overall annual social cost of CKD was €1,809,552,398 representing 0.11 % of the Gross Domestic Product. Direct non-medical costs and indirect costs were weighted on the social cost of CKD almost as much as the direct medical cost. Patients, their families and the productivity system sustain the burden of the disease almost as much as the healthcare system.

Protein-energy wasting and nutritional supplementation in patients with end-stage renal disease on hemodialysis

BACKGROUND & AIMS

Protein-Energy Wasting (PEW) is the depletion of protein/energy stores observed in the most advanced stages of Chronic Kidney Disease (CKD). PEW is highly prevalent among patients on chronic dialysis, and is associated with adverse clinical outcomes, high morbidity/mortality rates and increased healthcare costs. This narrative review was aimed at exploring the pathophysiology of PEW in end-stage renal disease (ESRD) on hemodialysis. The main aspects of nutritional status evaluation, intervention and monitoring in this clinical setting were described, as well as the current approaches for the prevention and treatment of ESRD-related PEW.

METHODS

An exhaustive literature search was performed, in order to identify the relevant studies describing the epidemiology, pathogenesis, nutritional intervention and outcome of PEW in ESRD on hemodialysis.

RESULTS AND CONCLUSION

The pathogenesis of PEW is multifactorial. Loss of appetite, reduced intake of nutrients and altered lean body mass anabolism/catabolism play a key role. Nutritional approach to PEW should be based on a careful and periodic assessment of nutritional status and on timely dietary counseling. When protein and energy intakes are reduced, nutritional supplementation by means of specific oral formulations administered during the hemodialysis session may be the first-step intervention, and represents a valid nutritional approach to PEW prevention and treatment since it is easy, effective and safe. Omega-3 fatty acids and fibers, now included in commercially available preparations for renal patients, could lend relevant added value to macronutrient supplementation. When oral supplementation fails, intradialytic parenteral nutrition can be implemented in selected patients.

Phosphate balance in ESRD: diet, dialysis and binders against the low evident masked pool

Phosphate metabolism is crucial in the pathophysiology of secondary hyperparathyroidism and vascular calcification. High phosphate levels have been consistently associated with unfavorable outcomes in dialysis patients, but several limitations are still hampering a resolutive definition of the optimal targets of phosphate serum levels to be achieved in this cohort. Nonetheless, hyperphosphatemia is a late marker of phosphate overload in humans. Clinical nephrologists routinely counteract the positive phosphate balance in dialysis patients through nutritional counseling, stronger phosphate removal by dialysis and prescription of phosphate binders. However, the superiority against placebo of phosphate control by diet, dialysis or binders in terms of survival has never been tested in dedicated randomized controlled trials. The present review discusses this conundrum with particular emphasis on the rationale supporting the value of a simultaneous intervention against phosphate overload in dialysis patients via the improvement of dietary intakes, dialysis efficiency and an individualized choice of phosphate binders.

Total parathyroidectomy without autotransplantation for the treatment of secondary hyperparathyroidism associated with chronic kidney disease: clinical and laboratory long-term follow-up

Forty-six consecutive patients who underwent total parathyroidectomy (tPTX) for hyperparathyroidism associated with end-stage kidney disease (CKD5) in a University Hospital from 1990 to 1999 were included in a long-term observational study. Outcome parameters included symptoms (bone pain, pruritus and muscle weakness evaluated by visual analog scales [VAS]) and laboratory data (intact parathyroid hormone [iPTH], total calcium, and alkaline phosphatase) assessed before, shortly postoperatively and then at a later time point: 40 patients were on maintenance hemodialysis and six on conservative medical therapy. Forty-four patients had four glands removed, while only three glands were found in the remaining two. Perioperative complications consisted of acute symptomatic hypocalcemia in 10 (22%) patients and non-specific complaints in three (7%). No laryngeal nerve palsies occurred. After a median follow-up of eight years, 43 subjects were evaluated: 37 (86%) were cured, three (7%) had persistent and three (7%) recurrent disease. Eleven patients underwent successful renal transplantation and 23 died during the period of observation. iPTH decreased from a mean of 1084+/-505 pg/ml to 120+/-381 pg/ml (p < 0.0001). No subsequent bone fractures, persistent bone pain or disability were reported; this includes patients who later received a functioning renal graft. tPTX was able to correct hyperparathyroidism in most of the patients and was associated with a low long-term relapse rate. iPTH levels remained low in 17 cases without symptoms and no clinically significant side effects. The beneficial effects of tPTX occurred in the majority of patients while renal transplantation was performed in a minority of patients. tPTX should be considered a safe and successful procedure for the treatment of severe secondary hyperparathyroidism associated with chronic kidney disease.

Prevalence of low back pain in former rhythmic gymnasts

AIM

It is still debated as to whether rhythmic gymnastics is a discipline at risk of low back pain, because the concern for the extreme and repetitive hyperextension of the column may be counteracted by protective factors which are distinctive of rhythmic gymnasts, namely: leanness, lumbar flexibility and muscle strength. This study aimed to assess the prevalence of low back pain in a cohort of former elite-level rhythmic gymnasts of the Rhythmic Gymnastics National Team.

METHODS

The Study Group included 60 adult females who were former rhythmic gymnasts of the Italian National Team. The Control Group included 60 adult females comparable for age, who were never involved in high level sport competitions. A standardized questionnaire was used to evaluate low back-pain symptoms.

RESULTS

Low back pain complaints were reported by 22 former rhythmic gymnasts and by 28 controls (36.6% vs. 46.6%, p: n.s.); in the ex-gymnasts the age of onset of pain was earlier than in controls. The former rhythmic gymnasts complaining low back pain reported a higher prevalence of symptoms also during the time of competitions, and retired earlier than those without pain.

CONCLUSIONS

Former elite rhythmic gymnasts reported a prevalence of low back-pain similar to sex and age matched general population. However, the rhythmic gymnasts who complained back pain during the sport activity are at risk of an early onset of symptoms after the retire from competitions. This study suggests that rhythmic gymnastics is not associated with increased risk of low back pain in the adult age.

[Low-protein diet in Italy today: the conclusions of the Working Group from the Italian Society of Nephrology]

The high estimated prevalence of chronic kidney disease (CKD) forcefully supports the need for collaboration among nephrologists, cardiologists, diabetologists and general practitioners, to reduce the cardiovascular risk of CKD patients and delay the start of dialysis. Many studies confirm that reducing the dietary intake of proteins improves uremia as well as acid-base and phosphorus disorders without exposing the CKD patient to the risk of malnutrition. The possibility of delaying renal death and the start of dialysis by almost one to two years is also recognized, thanks in part to the antiproteinuric effect of low-protein diets supplemented with keto acids and essential amino acids. Reducing the dietary protein intake delays the start of dialysis independently of the effect of renin-angiotensin system (RAS)-active antihypertensive drugs. Reduction of the dietary protein intake is indicated in patients with a glomerular filtration rate <25 mL/min (CKD stages 4 and 5). Some situations may, however, require an earlier switch to a low-protein diet, e.g., high proteinuria, renal function worsening at more than 5 mL/min/year, diabetes, and metabolic decompensation. If well designed and properly carried out, reduction of the dietary intake of proteins is not associated with low serum albumin levels or malnutrition, and does not affect patients death. Today, highly palatable, high-quality reduced protein preparations are widely available to reduce the protein intake of CKD patients.

[Low-protein dietary therapy in patients with chronic kidney disease]

Several prospective studies and meta-analyses including the recent Cochrane meta-analysis have demonstrated that reducing the protein content in the diet delays renal death and the start of dialysis in patients with chronic kidney disease (CKD). Reducing the dietary protein intake offers other benefits such as lowering accumulation of uremic toxins and circulating phosphates and improving symptoms and metabolic derangements. Following the publication of the Cochrane meta-analysis, some of the most renowned experts in Italy on dietary therapy in the CKD patient established a working group within the Italian Society of Nephrology (SIN), the ''Nephrontieres'' project. The current supplement of GIN presents the views of the members of the ''Nephrontieres'' group on a range of issues related to dietary therapy in CKD. A CME program for Italian nephrologists also originated from the collaborative work of the group.

[Definition of the nutritional therapy in the conservative treatment of chronic kidney disease]

Nutritional therapy has a leading role in the conservative treatment of chronic kidney disease (CKD). In the context of CKD, nutritional therapy means designing diets to reduce the patient's intake of proteins, phosphorus and sodium, while preserving adequate energy intake. Nutritional therapy may require also supplementation with calcium carbonate, iron, or essential amino acids and keto acids. Different nutritional strategies can be devised according to the protein needs of CKD patients: diets with controlled protein intake (protein RDA: 0.8 g/kg/day); low-protein and low-phosphorus diets (protein: 0.6 g/kg/day, phosphorus: 500-700 mg/day); very low-protein and low-phosphorus diets (protein: 0.3 g/kg/day, phosphorus: 300-400 mg/day). Much of the protein intake should be of high biological value (e.g., 0.4 g/kg/day of 0.6 g/kg/day or supplementation with essential amino acids and keto acids is needed). The sodium chloride content of low-protein and very low-protein diets should be kept between 2 and 5 g/day according to individual needs, and the energy intake should be kept at 30 to 35 kcal/kg/day.

Injury survey in competitive sub-elite rhythmic gymnasts: results from a prospective controlled study

AIM

The aim of this study was to determine the frequency, anatomical site and types of injury incurred in rhythmic gymnastics.

METHODS

An 8-month prospective and controlled injury survey was planned, including 70 club-level competitive rhythmic gymnasts, aged 13-19 years. Information on injury events was recorded weekly in an injury record booklet for any event occurring over that week. Height, weight, anthropometric measurements and time spent in physical activity were recorded at baseline. Data from 72 age-matched non-athletic females served as controls.

RESULTS

Forty-nine significant injuries were reported by gymnasts and 34 by controls (70% vs 47%, P<0.005, odds ratio 2.28); gymnasts sustained a rate of 1.08 injuries per 1 000 h of training. The most prevalent anatomical sites sustaining injury were the ankle and the foot (38.9%), followed by back (22.2%). Strains and sprains were frequently reported both in gymnasts and in controls. Gymnasts missed an average of 4.1 days of physical activity as compared to 18.9 days for the control females. Alternatively, modification of training sessions occurred more frequently for the gymnast group (32 vs 7 cases for controls). The total school days missed were lower for the injured gymnasts than for the injured controls (27 vs 64 days).

CONCLUSION

Competitive, club-level rhythmic gymnastics show a higher prevalence of injuries than non-athletic controls, but considering the high number of hours spent in training sessions, it derives that rhythmic gymnasts is a sport discipline at relatively low risk of severe injuries. These are mainly limited to back and lower limbs, are generally not severe and do not significantly hinder the preparation for the competitions.

Insulin resistance and low urinary citrate excretion in calcium stone formers

Epidemiological data suggest an association between kidney stones and some features of metabolic syndrome such as an overweight condition, arterial hypertension or glucose intolerance. However, mechanisms remain to be elucidated. This study aimed to evaluate insulin resistance, as assessed by homeostasis model assessment (HOMA-IR), and urine composition analysis in patients affected by calcium nephrolithiasis. A cohort of 61 (38 male, 29-57 years of age) non-diabetic calcium stone formers was studied. Data about body mass index, arterial blood pressure, serum biochemistry including parathyroid hormone and calcitriol were recorded in all the patients; fasting glucose and insulin were determined to calculate HOMA-IR value and accordingly the patients were grouped into tertiles. Urine pH and urinary excretion of calcium, citrate, phosphate, oxalate, uric acid, urea and creatinine were measured on 24h urine samples. Patients of the highest HOMA-IR tertile showed lower urine citrate levels than patients of the lowest HOMA-IR tertile (475+/-243 vs. 630+/-187 mg/24h, p<0.05), whereas no difference was detected as far as urinary oxalate, calcium, uric acid, phosphate, and urine pH and urine volume output were concerned. HOMA-IR values were positively related to uric acid serum levels (r=0.31, p<0.05) and negatively to urinary citrate excretion (r=-0.26, p<0.05). Hypocitraturic patients showed higher levels of HOMA-IR than normocitraturic ones (3.03+/-0.92 vs. 2.25+/-1.19, p<0.05). This study shows that a higher level of insulin resistance is associated with lower urinary citrate excretion, and that hypocitraturic patients show a greater insulin resistance than normocitraturic calcium stone formers. This may be related to changes in citrate, Na(+)-K(+) and H(+) renal tubule transports, which have been described in insulin resistance. In conclusion, insulin resistance may contribute to an increased risk of calcium stone formation by lowering urinary citrate excretion. This finding suggests the need for a careful metabolic assessment in patients known to form calcium stones in order to ensure stone recurrence prevention and cardiovascular protection.

Left ventricular function and calcium phosphate plasma levels in uraemic patients

BACKGROUND. Recent investigations have focused on the pathogenetic role of disturbances of calcium phosphate metabolism in causing cardiovascular morbidity and mortality in haemodialysis patients. The aim of the present study was to assess left ventricular function and its relationship to phosphate and calcium plasma levels in stable uraemic patients on haemodialysis treatment.

METHODS

Twenty uraemic patients (mean age 51+/-13 years) on maintenance haemodialysis and free from overt cardiac dysfunction, and 20 healthy volunteers underwent standard echocardiography, tissue Doppler-derived early (E(m)) and late (A(m)) diastolic velocities, tissue characterization with cyclic variations of integrated backscatter (CV-IBS), and serum biochemistry.

RESULTS

With respect to tissue Doppler imaging (TDI), uraemic patients showed a lower E(m) peak, a higher A(m) peak, and a reduced E(m)/A(m) ratio of both interventricular septum and lateral wall (0.01>P<0.001) than controls. CV-IBS of both septum and posterior wall was significantly smaller in uraemic patients than in the control subjects (P<0.001). Moreover, the E(m)/A(m) ratio of septum and lateral wall were negatively related to serum phosphorus and to calcium phosphate product (P<0.001 for all). Accordingly, an inverse relationship was also found between CV-IBS of septum and lateral wall and calcium phosphate product and phosphorus (P<0.05 for all).

CONCLUSIONS

These results showed early cardiac impairment of diastolic myocardial function evaluated by TDI and IBS analysis, and a close relationship between these changes and the calcium-phosphate plasma levels. These findings are well in keeping with the important role of hyperphosphataemia as a risk factor for cardiovascular damage, and justify the effort for optimal control of calcium phosphate metabolism in uraemic patients.

Cardiovascular risk factors in severe chronic renal failure: the role of dietary treatment

BACKGROUND

Lipoprotein abnormalities and increased oxidized LDL (OxLDL) are often observed in uremia and are reported to play a central role in the development of cardiovascular disease (CVD). Vegan diet, known for its better lipoprotein profile and antioxidant vitamins content, could protect against CVD. Aim of this study was to investigate the influence of vegan diet supplemented with essential amino acids (EAA) and ketoanalogues (VSD) on both traditional and non-traditional cardiovascular risk factors (CVRF).

METHODS

Twenty-nine patients (18 M, 11 F) aged 55 years (range 29-79 years) with advanced chronic renal failure (median sCr: 5.6 mg/dl) on very low protein vegetarian diet (0.3 g/kg/day) supplemented with a mixture of EAA and ketoacids (VSD) and 31 patients (20 M, 11 F) aged 65 years (range 29 - 82 years) on conventional low-protein diet (CD: 0.6 g/kg/day) with a similar renal function (median sCr: 5.2 mg/dl), were investigated for lipids and apolipoprotein parameters (traditional CVRF) as well as for oxidative stress (oxidized LDL, antibodies against OxLDL and thiobarbituric acid-reactive substances (TBARS)), total homocysteine (tHcy), lipoprotein(a) (Lp(a)), albumin and c-reactive protein (CRP) (non-traditional CVRF) including vitamins A, E, B12 and folic acid.

RESULTS

Compared to patients on CD, those on VSD showed increased HDL cholesterol levels (p < 0.005) with a reduction of LDL cholesterol (p < 0.01) and an increase of apoA1/apoB ratio (p < 0.02). Among non-traditional CVRF, a mild but significant reduction of OxLDL (p < 0.05) with lower TBARS concentrations (p < 0.01) and a significant reduction of total homocysteine (p < 0.002), Lp(a) (p < 0.002) and CRP levels (p < 0.05) were also observed in these patients. Concentrations of vitamin E and A were not different between the two groups while vitamin B12 and folic acid resulted markedly increased in patients on VSD. OxLDL significantly correlated with total and LDL cholesterol, triglycerides and Apo B in CD but not in VSD patients. Patients on CD also showed a significant correlation between urea and CRP. After a multivariate analysis, only urea (p < 0.001) and OxLDL (p < 0.006) were associated to a risk of CRP > 0.3 mg/dl.

CONCLUSIONS

These results indicate a better lipoprotein profile in patients on vegan diet including non-traditional CVRF. In particular, these patients show a reduced oxidative stress with a reduced acute-phase response (CRP) as compared to patients on conventional diet. We hypothesize that urea, significantly lower in patients on VSD, may account, possibly together with the reduction of other protein breakdown products, for the decreased acute-phase response observed in these patients. Our findings suggest that low-protein diets, and vegan in particular, may exert a beneficial effect on the development of cardiovascular disease in patients with end-stage renal disease (ESRD).

Low back pain in competitive rhythmic gymnasts

AIM

It has been reported that rhythmic gymnasts are at risk of suffering from low back injuries, because of repetitive lumbar hyperextensions. On the other hand, this sport requires features of leanness, muscular strength and flexibility that should represent protective factors for back pain.

METHODS

This cross-sectional study aimed to assess the prevalence of low back pain in 67 club-level competitive rhythmic gymnasts aged 13-19 years. A standardized questionnaire was used to evaluate back-pain symptoms. Anthropometric measurements, time spent in physical activity, psychological testing results, smoking habits and age of menarche were recorded. One hundred and four age-matched general females served as control group.

RESULTS

Low back pain complaints were reported by 7 rhythmic gymnasts and by 27 controls (10.4% vs 26.0%, p<0.05); the prevalent location of back pain was bilateral in gymnasts and central in controls. Gymnasts had lower body weight, body mass index, fat body mass and delayed menarche. The females with low-back pain displayed higher body weight, body mass index, fat body mass, age, a greater smoking habit and more anxious/depressive behaviour, both in the gymnast and in the control group.

CONCLUSION

Competitive, club-level rhythmic gymnasts show a reduced prevalence of low back-pain. Being younger in age, having greater leanness, not smoking, displaying less anxious/depressive behaviour, and developing increased muscle strength and flexibility, all can represent preventive factors for low back pain. This study suggests that rhythmic gymnastics is not a discipline at increased risk of low back pain.

Ultrasonic backscatter of the carotid wall in young and older athletes

OBJECTIVES

The aim of this study was to evaluate the effects of habitual exercise on the age-related changes of carotid wall composition defining its acoustic reflectivity by the quantitative approach of integrated backscatter (IBS) analysis.

DESIGN

Cross-sectional study.

SETTING

University Hospital.

SUBJECTS

Fifty-four competitive long-distance runners (males, age range 22-72 years) and 50 healthy sedentary controls.

MAIN OUTCOME MEASURES

All the subjects underwent both 2-D conventional ultrasonography and IBS analysis. IBS values were sampled from a region of interest (ROI) placed within five consecutive regions of the common carotid intima-media, and then corrected (C-IBS) for the IBS value of the adventitia.

RESULTS

Athletes showed a lower C-IBS (-27.07 +/- 2.9 dB vs. -24.57 +/- 4 dB, P < 0.0001) and a smaller intima-media thickness (IMT: 0.64 +/- 0.16 mm vs. 0.78 +/- 0.21 mm, P < 0.001) respect to sedentary controls. By selecting the lowest (<30 years of age) and the highest (>60 years of age) tertile of age, we assess the influence of age on IMT and IBS. Sedentary older individuals exhibited an IMT higher respect to young controls and to the both trained subgroups (P < 0.0001). C-IBS was lower in both subgroups of athletes, independently of age, and lower in sedentary young people respect to sedentary older subgroup (P < 0.0001). Endurance chronic exercise blunted the difference of C-IBS observed between young and older sedentary individuals. Moreover, C-IBS was positively related to age (r = 0.77, P < 0.0001) and IMT (r = 0.52, P < 0.0001).

CONCLUSIONS

The age-related changes of the arterial wall are attenuated by physical training. These modifications can be quantitatively discriminated by ultrasonic backscatter method.

Skeletal muscle and nutritional assessment in chronic renal failure patients on a protein-restricted diet

BACKGROUND

The close relationship between protein-energy malnutrition and quality of life, morbidity and mortality, makes mandatory a careful evaluation of the nutritional status and muscle mass in chronic renal failure (CRF) patients.

METHODS

Nutritional and skeletal muscle data were obtained from 28 nondiabetic patients with severe CRF (glomerular filtration rate, GFR < 15 mL min-1) on conservative treatment. Of them, 14 (8 males, 4 females) were on a conventional low-protein (0.6 g kg-1 body weight) diet (LPD) and 14 (8 males, 4 females) were on a very low-protein (0.3 g kg-1 body weight) diet supplemented with essential amino acids and ketoacids (Ketodiet); 28 healthy sex- and age-matched subjects served as controls. We evaluated biochemistry, anthropometry, bioelectrical impedance vector analysis, and three noninvasive tests investigating some skeletal muscle features: (a) myoelectrical fatigue phenomenon was studied using a surface electromyography technique that provides data on conduction velocity (CV), median frequency of power spectrum (MDF) and average rectified value (ARV) of myofibre action potential, at 15 and 35 Hz stimulation frequency; (b) muscle oxidative metabolism was studied by serum lactate following aerobic exercise; and (c) muscle strength of the legs was studied using an isokinetic exercise test at two different angular velocities (60 degrees and 180 degrees s-1).

RESULTS

No difference between patients and controls was detected regarding CV, MDF and ARV, at 35 and 15 Hz testing. Serum lactate was higher in patients than in controls at 1, 5, 10 and 30 min recovery. A decreased knee extension and flexion strength was detected in CRF patients both at low (60 degrees s-1) and at high (180 degrees s-1) angular velocity; muscle strength deficit negatively correlated to serum albumin (r = -0.52, P < 0.01), but no relationship was found with protein intake or residual renal function. No difference was found between LPD and Ketodiet patients regarding the studied muscular tests as well as the anthropometry and bio-impedance data.

CONCLUSIONS

Implementation of a proper dietary regimen, including severe restriction of protein intake can preserve lean body mass and nutritional status of advanced CRF patients. Skeletal muscle shows unchanged sarcolemma excitability but abnormal oxidative metabolism and reduced segmental strength. Regular physical activity and a close clinical and dietary monitoring should be recommended for the predialysis patient care.

Ultrasonic tissue characterization of the myocardium in anorexia nervosa

AIM

To determine the systodiastolic variations in the integrated backscatter (IBS) signal of the myocardium in patients with anorexia nervosa.

METHODS

25 young women (aged 22.4 +/- 4.3 y) with overt anorexia nervosa, compared with 25 age-matched thin and 25 age-matched control women with body mass index >20 kg m(-2), underwent either conventional two-dimensional echocardiography or analysis of IBS cyclic variations.

RESULTS

Compared with thin and control subjects, anorectic patients showed reduced left ventricular mass (LVM: 82.9 +/- 17.1 vs 119.9 +/- 13.8 and vs 126.12 +/- 16.4 g, p < 0.0001; LVM indexed 21.4 +/- 3.3 vs 29.4 +/- 2.5 and vs 31.2 +/- 3.1 g m(-2.7), p < 0.0001), and IBS cyclic variations (septum: -0.49 +/- 2.18 vs 6.86 +/- 1.3 and vs 6.61 +/- 1.74 dB p < 0.0001; posterior wall: 2.77 +/- 2.12 vs 7.15 +/- 2.12 and vs 7.48 +/- 2.23 dB, p < 0.01).

CONCLUSION

Anorexia nervosa is associated with a significant reduction in the cyclic variation in IBS, which is also related to left ventricular hypotrophy. Ultrasonic tissue characterization could give an objective approach for the detection of myocardial structural properties and represent a preclinical index of myocardial dysfunction in anorexia nervosa.

Changes in heart rate variability in chronic uremic patients during ultrafiltration and hemodialysis

BACKGROUND

The analysis of heart rate variability (HRV) is a useful tool to evaluate cardiac autonomic modulation, which is frequently impaired in chronic uremia.

AIMS

The aim of this study was to evaluate HRV in chronic uremics and to separately investigate the acute changes induced by volume depletion and solute removal during a hemodialysis session.

METHODS

Fourteen uremic patients (8 males and 6 females, aged 50 +/- 15 years) on maintenance hemodialysis and 14 sex- and age-matched healthy controls were studied. Both groups underwent ambulatory electrocardiogram monitoring to evaluate the HRV time and frequency domain indices. The hemodialysis session was performed by 1 h of high-rate isolated ultrafiltration followed by 3 h of bicarbonate diffusive procedure.

RESULTS

In uremic patients, the overall variability in the frequency [low-frequency power (LF): 505 +/- 473, vs. 1,446 +/- 654; high-frequency power (HF): 133 +/- 162 vs. 512 +/- 417; p < 0.001] and time domain indices (standard deviation of normal R-R intervals: 101.9 +/- 33.3 vs. 181.7 +/- 44.1 ms; p < 0.001) was markedly reduced compared to controls, whereas mean heart rate (83 +/- 12.4 vs. 60.9 +/- 8.8 bpm; p < 0.001) and LF/HF ratio (5.8 +/- 3.5 vs. 2.2 +/- 0.8; p < 0.001) were increased. Isolated ultrafiltration produced a marked further decrease in HRV indices, but the subsequent diffusive hemodialysis procedure, with a low ultrafiltration rate, made HRV increase again.

CONCLUSIONS

Chronic uremics showed abnormal autonomic modulation with sympathetic-vagal imbalance. The unbalanced hypersympathetic response to body fluid depletion is related to the ultrafiltration rate. Low interdialytic weight gain and a low ultrafiltration rate, associated with adequate hemodialysis, should be the preferable strategy for uremic patients with autonomic dysfunction.

Responses of the skin microcirculation to acetylcholine and to sodium nitroprusside in chronic uremic patients

The aim of the present study was to assess the endothelial function of the microcirculation in chronic renal failure. We investigated the responses of the cutaneous blood flow to locally delivered acetylcholine and sodium nitroprusside in uremic patients. The study included 60 chronic uremic patients: 40 patients with a creatinine clearance of 4-25 ml/min were on conservative treatment and 20 patients were on maintenance hemodialysis. The changes in skin blood flow following iontophoretic delivery of acetylcholine (an endothelium-dependent vasodilator) and sodium nitroprusside (an endothelium-independent vasodilator) were measured by laser Doppler flowmetry. Acetylcholine induced a progressive increase in blood flow in both groups, reaching approximately 100% of the maximal hyperemic response obtained by sodium nitroprusside delivery. The percent increase in blood flow from baseline was lower in hemodialysis patients than in patients on conservative treatment, after both acetylcholine (550 +/- 44 vs. 718 +/- 61%, P < 0.05) and sodium nitroprusside (553 +/- 46 vs. 735 +/- 69%, P < 0.05) delivery. In the hemodialysis group, the hyperemic responses to acetylcholine and sodium nitroprusside did not improve after the hemodialysis session. Hence, the hyperemic responses of the skin microcirculation are lower in hemodialysis patients than in patients on conservative treatment, and did not ameliorate after hemodialysis. It seems to be independent of endothelial dysfunction, and associated with the severity of uremia and with the maintenance hemodialysis treatment. This microcirculatory abnormality is in keeping with the arterial stiffness and vascular wall damages described in dialysis patients, which contribute to the cardiovascular morbidity of chronic uremia.

Nutrition survey in elite rhythmic gymnasts

BACKGROUND

Young female rhythmic gymnasts have been identified as a potential risk group for malnutrition because of their attitude of weight reduction and leanness.

METHODS

This study aimed to assess the dietary practices of 20 rhythmic gymnasts of the Italian national team, on the basis of a three-day food records collected by clinical interview. Twenty-four age-matched non-athletic females served as controls.

RESULTS

The reported energy intake was similar in gymnasts and controls (28.5+/-5.6 vs 28.2+/-7.8 kcal/kg b.w., per day), but less than the recommended and the estimated requirements. Energy intake from carbohydrates was higher (53+/-6 vs 49+/-6%, p<0.05) and that from lipids lower (31+/-6 vs 34+/-4%, p<0.05) in gymnasts than in controls. In the former the energy supply from breakfast was higher (24+/-2 vs 16+/-4%, p<0.001) and from snacks was lower (8+/-9 vs 17+/-10%, p<0.01). Gymnasts also distinguished from controls for lower cholesterol and saturated fatty acid intake, and for higher fibre (14+/-5 vs 9+/-2 g/1,000 kcal, p<0.001) and Vitamin A dietary content. Calcium, iron and zinc intake were less than 100% RDA in both groups.

CONCLUSIONS

In some ways, dietary practices of rhythmic gymnasts meet nutritional recommendations more than those of non athletic controls, though discrepancy between reported energy intake and estimated energy requirement exists. Suboptimal calcium, iron and zinc intake were observed both in gymnasts and in controls, hence minerals supplementation could be required. The dietary attitude could be regarded as a positive aspect of rhythmic gymnastics, provided athletes, physicians and coaches correct dietary errors and avoid excessive food restrictions.

Effect of hemodialysis on the dispersion of the QTc interval

The QTc dispersion reflects the underlying regional heterogeneity of the recovery of the ventricular excitability, thereby it is considered as a novel marker of risk of ventricular arrhythmias. Because a higher incidence of ventricular arrhythmias is described during and after hemodialysis, the aim of this study has been to evaluate the QTc dispersion before and after uncomplicated hemodialysis session. Twenty chronic uremics without heart failure, ischemic heart disease or dialysis hypotension were selected. The QTc dispersion was determined as the difference between the longer and the shorter QTc interval measured on a 12-lead electrocardiogram. Following the hemodialysis session, the QTc dispersion increased from 30 +/- 9 to 54 +/- 17 ms (p < 0.001) associated with the expected reduction of potassium and magnesium and with the increase of extracellular calcium concentration. However, no correlation has been observed between the QTc dispersion increase and the degree of the intradialytic changes of plasma electrolytes, blood pressure or body weight. In summary, the hemodialysis treatment per se does induce an increase of the QTc dispersion, likely due to the rapid changes of electrolyte plasma concentrations. This can potentially contribute to the arrhythmogenic effect of the hemodialysis procedure, reflecting an enhanced regional heterogeneity of ventricular repolarization. The clinical importance of the increase of QTc dispersion as risk factor of ventricular arrhythmias, particularly in hemodialyzed patients suffering from ischemic or hypertrophic heart diseases, should be the matter of further investigations.

Secondary hyperparathyroidism in severe chronic renal failure is corrected by very-low dietary phosphate intake and calcium carbonate supplementation

The main purpose of our study was to verify the effect of a very-low-protein, low-phosphorus diet, supplemented with essential amino acids and keto analogues and with calcium carbonate, on circulating levels of intact parathyroid hormone (i-PTH) in severe chronic renal failure patients with secondary hyperparathyroidism, not treated with any vitamin D preparation. To this aim, we shifted 21 chronic uremics (12 males, 9 females; age 56 +/- 13 years) with serum creatinine >6.5 mg/dl and i-PTH >150 pg/ml, from a standard low-protein diet (0.6 g/kg/day approximately) to a very-low-protein (0.3 g/kg/day), very-low-phosphorus (5 mg/kg/day) diet supplemented with a mixture of essential amino acids and calcium keto analogues (Ketodiet), calcium carbonate (2-4 g/day), iron, and vitamin B12 preparations. The energy supply of both diets was 30-35 kcal/kg/day. Exclusion criteria were a poor compliance with dietary or supplement prescriptions or signs of autonomic hyperparathyroidism. After 4 +/- 2 months of Ketodiet, the i-PTH serum levels decreased by 49% as a mean (from 441 +/- 233 to 225 +/- 161 pg/ml, p < 0.001); serum phosphorus and alkaline phosphatase decreased, whereas serum calcium increased. The great reduction of serum and urinary urea demonstrated a good compliance with Ketodiet, and no sign of protein malnutrition was observed. These findings confirm that even in severe chronic uremic patients dietary phosphorus restriction and calcium carbonate supplementation lower i-PTH serum levels. This is one of the goals of the dietary treatment that can be safely achieved, provided good compliance both with the dietary prescriptions and with adequate energy and supplement intakes.

Effects of oral administration of heparan sulphate in the rat remnant kidney model

Heparins are useful for the protection of residual renal function in several nephropathies, but the anticoagulant action and the need of parenteral administration are two main drawbacks limiting their use in chronic renal failure patients. Heparan sulphate (HS) is a heparin-like mucopolysaccharide devoid of anticoagulant action and active orally. In this study, the effects of HS oral administration have been evaluated in 18 subtotally nephrectomized rats;18 untreated remnant kidney rats served as control. No mortality was observed in the HS-treated rats, whereas in the control rats the survival rate was 72.2% at 18 weeks. At the end of the study, HS-treated rats showed lower urinary protein excretion (44 +/- 22 vs. 80 +/- 54 mg/24 h, p < 0.01), lower urea plasma levels (75 +/- 34 vs. 134 +/- 105 mg/dl, p < 0.01) and higher creatinine clearance (66 +/- 15 vs. 47 +/- 21 ml/min. 10(2), p < 0.05) than control rats. Remnant kidney weight (2.3 +/- 1.1 vs. 1.3 +/- 0.2 g, p < 0.01) and heart weight (1.3 +/- 0.2 vs. 1.1 +/- 0.1 g, p < 0.05) were greater in the control than in the HS-treated rats, as well as the systemic blood pressure values (167 +/- 19 vs. 115 +/- 32 mm Hg, respectively, p < 0.001). The remnant kidney histological examination in the HS-treated rats showed a lower prevalence of glomerular sclerosis, mesangial proliferation, and a much less evident tubulointerstitial damage than in controls. The antiproliferative and anti-inflammatory actions of HS together with its protective action on the endothelium are the putative mechanisms that could account for our findings. In conclusion, the present study supports evidence of an antiproteinuric and a renoprotective effect of orally administered HS in subtotally nephrectomized rats. This is in keeping with the well-known effects exerted also by other heparins, but the effectiveness of an orally available heparin-like product in this animal model could suggest the possibility of a clinical use also in progressing chronic renal failure patients.

Responses of the skin microcirculation to acetylcholine in patients with essential hypertension and in normotensive patients with chronic renal failure

AIMS

To assess the endothelial function of the skin microcirculation in chronic renal failure (CRF) independent of hypertension, we investigated the changes of the cutaneous blood flow induced by iontophoretic delivery of acetylcholine (ACh) and of sodium nitroprusside (SNP) in CRF patients free from arterial hypertension and in patients with essential hypertension.

METHODS

The study included 20 patients affected by CRF (mean creatinine clearance 12+/-2 ml/min) without arterial hypertension (mean blood pressure 96+/-1 mm Hg), 15 patients affected by essential hypertension (mean blood pressure 124 +/-1 mm Hg), and 20 normal controls. The changes of skin blood flow following iontophoretic delivery of ACh and of SNP were measured by laser Doppler flowmetry.

RESULTS

Following maximal ACh or SNP delivery, the change of blood flow from the baseline was similar both in normals (683+/-92 vs. 684 +/- 87%) and in CRF patients (778+/-108 vs. 803+/-124%), whereas in the hypertensives the response to ACh was lower than to SNP (434+/-48 vs. 702 +/- 98%, p<0.01). Since the third ACh delivery dose, the skin blood flow increments were significantly lower in the hypertensive than in the CRF or in the normal control groups, whereas no difference was observed between uremics and controls.

CONCLUSIONS

The endothelium-dependent hyperemia following ACh iontophoretic delivery is impaired in the skin microcirculation of essential hypertensive patients, but this is not the case in CRF patients with no history of arterial hypertension. This suggests that CRF per se, independent of arterial hypertension, is not associated with endothelial dysfunction of skin microcirculation.