Perspective: A Research Roadmap about Ultra-Processed Foods and Human Health for the United States Food System: Proceedings from an Interdisciplinary, Multi-Stakeholder Workshop

Our objective was to convene interdisciplinary experts from government, academia, and industry to develop a Research Roadmap to identify research priorities about processed food intake and risk for obesity and cardiometabolic diseases (CMD) among United States populations. We convened attendees at various career stages with diverse viewpoints in the field. We held a "Food Processing Primer" to build foundational knowledge of how and why foods are processed, followed by presentations about how processed foods may affect energy intake, obesity, and CMD risk. Breakout groups discussed potential mechanistic and confounding explanations for associations between processed foods and obesity and CMD risk. Facilitators created research questions (RQs) based on key themes from discussions. Different breakout groups convened to discuss what is known and unknown for each RQ and to develop sub-RQs to address gaps. Workshop attendees focused on ultra-processed foods (UPFs; Nova Group 4) because the preponderance of evidence is based on this classification system. Yet, heterogeneity and subjectivity in UPF classification was a challenge for RQ development. The 6 RQs were: 1) What objective methods or measures could further categorize UPFs, considering food processing, formulation, and the interaction of the two? 2) How can exposure assessment of UPF intake be improved? 3) Does UPF intake influence risk for obesity or CMDs, independent of diet quality? 4) What, if any, attributes of UPFs influence ingestive behavior and contribute to excess energy intake? 5) What, if any, attributes of UPFs contribute to clinically meaningful metabolic responses? 6) What, if any, external environmental factors lead people to consume high amounts of UPFs? Uncertainty and complexity around UPF intake warrant further complementary and interdisciplinary causal, mechanistic, and methodological research related to obesity and CMD risk to understand the utility of applying classification by degree of processing to foods in the United States.

Structural and Thermal Characterization of Protein Isolates from Australian Lupin Varieties as Affected by Processing Conditions

Proteins from the full and defatted flours of L. angustifolius cv Jurien and L. albus cv Murringo were prepared using alkaline extraction and iso-electric precipitation. Isolates were either freeze dried or spray dried or pasteurized at 75 ± 3 °C/5 min before freeze-drying. Various structural properties were investigated to elucidate the varietal and processing-induced effect on molecular and secondary structure. Irrespective of processing, isolated proteins had a similar molecular size, with α-conglutin (412 kDa) and β-conglutin (210 kDa) being principal fractions for the albus and angustifolius variety, respectively. Smaller peptide fragments were observed for the pasteurized and spray dried samples, indicating some degree of processing-induced changes. Furthermore, secondary structure characterization by Fourier-transform-infrared and circular dichroism spectroscopy showed β-sheet and α-helical structure being the dominant structure, respectively. Thermal characterization showed two denaturation peaks corresponding to β-conglutin (T_d = 85-89 °C) and α-conglutin (T_d = 102-105 °C) fractions. However, the enthalpy values for α-conglutin denaturation were significantly higher for albus species, which corroborates well with higher amounts of heat stable α-conglutin present. Amino acid profile was similar for all samples with limiting sulphur amino acid. In summary, commercial processing conditions did not have a profound effect on the various structural properties of lupin protein isolates, and properties were mainly determined by varietal differences.

Meat Consumption and Gut Microbiota: A Scoping Review of Literature and Systematic Review of Randomized Controlled Trials in Adults Without Diagnosed Disease

Objectives

Meat is an important dietary component for the majority of the U.S. population. Emerging research indicates the importance of gut microbiota in mediating the relationship between meat intake and human health outcomes. We aim to assess the state of available scientific literature on meat intake and gut microbiota in humans.

Methods

We first conducted a scoping review to identify observational and interventional studies on this topic. Based on findings from the scoping review, we conducted a systematic review using suitable literature to assess the influence of meat intake on gut microbiota. Searches were performed for English language articles using PubMed, Cochrane Library, Scopus, and CINAHL databases from inception to August 2021, and keywords related to meat (inclusive of mammalian, avian, and aquatic subtypes) and gut microbiota.

Results

Of 14,680 records, 84 eligible articles were included in the scoping review, including 57 observational and 27 interventional studies. One prospective observational study and 13 randomized-controlled trials (RCTs) were identified in adults without diagnosed disease. We included the 13 RCTs, comprising 18 comparisons, in the systematic review to assess the effects of higher versus lower intakes of total meat and meat subtypes on gut microbiota composition. Collectively, meat intake differentially affected bacterial composition more frequently at lower taxonomic levels (genus or species) than higher taxonomic (phylum or class) or community structure (alpha diversity) levels. A similar hierarchical pattern of findings was observed when higher versus lower meat intakes (12 comparisons) or omnivorous versus vegetarian-style diets (7 comparisons) were assessed. Yet, the directionality and types of microbial responses varied, with no consistent pattern of responses across studies in bacterial taxa. The data were insufficient for comparison within or between meat subtypes.

Conclusions

The paucity of research, especially among meat subtypes, and heterogeneity of findings underscore the need for more well-designed prospective studies and full-feeding randomized-controlled trials to address the relationships between and effects of, respectively, consuming total meat and meat subtypes on gut microbiota.

Funding Sources

Beef Checkoff.

Whey Protein Supplementation and Type 2 Diabetes Mellitus Risk Factors: A Scoping Review of Systematic Reviews and/or Meta–Analyses of Randomized Controlled Trials

Objectives

Emerging research on whey protein supplementation WPS suggests it may be a potential modifier of type 2 diabetes mellitus (T2DM) risk factors, including glycemic regulation. As systematic reviews and/or meta-analyses of RCTS are gaining importance in nutrition literature, we conducted a scoping review to systematically search and chronicle published systematic reviews and/or meta-analyses of RCTs pertinent to WPS and T2DM modifiable risk factors.

Methods

The protocol was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews (PRISMA-ScR) guidelines. Potentially eligible articles were identified via a systematic search of five electronic health research databases (PubMed, Cochrane Library, CINAHL (EBSCO), Scopus, and SPORTDiscus). Included articles were assessed for quality using the AMSTAR-2 critical appraisal tool.

Results

Eight of the 1,692 identified articles met the inclusion criteria. Of the 8 included articles, the outcomes related to T2DM risk factors reported in articles were as follows; 4 included HDL-cholesterol and triglycerides; 3 included fasting blood glucose, total cholesterol, LDL-cholesterol, and body weight; 1 included fasting insulin, HbA1c, blood pressures BMI, and CRP. The results of AMSTAR 2 critical appraisal tool showed that of the 8 included articles, 5 were deemed high quality, 2 were deemed moderate quality, and 1 article was deemed low quality.

Conclusions

Results of the scoping review identified no published systematic reviews and/or meta-analyses of RCTs that provide a comprehensive assessment specifically pertaining to the effects of WPS on T2DM modifiable risk factors. Future systematic reviews and/or meta-analyses of RCTs specifically investigating the effects of WPS on modifiable T2DM risk factors in a comprehensive manner are warranted.

Funding Sources

The Whey Protein Research Consortium

Protein Intakes Greater Than vs. at the RDA Differentially Affect Lean Body Mass Change to Purposeful Catabolic and Anabolic Stressors: A Systematic Review and Meta-analysis (P08-075-19)

Objectives

Under stressful conditions such as energy restriction (ER) and resistance training (RT), recommended dietary allowance (RDA) for protein of 0.8 g/kg/d may no longer be an appropriate recommendation. Higher protein intakes are proposed to help promote, preserve, or attenuate the loss of lean mass. No known meta-analysis has been published previously that compares protein intakes greater than the RDA vs. the RDA as a control group. Therefore, we conducted a systematic review and meta-analysis to assess the effects of protein intake greater than versus at the RDA on changes in whole-body lean mass.

Methods

Three researchers independently screened 1531 articles published through August 2018 using PubMed, Scopus, CINAHL, and Cochrane databases, with additional articles identified through previously published review articles. Randomized-controlled, parallel studies at least 6 weeks long with apparently healthy adults (> = 19 years old) were eligible for data extraction. (PROSPERO, CRD 42018106532).

Results

Data from 19 studies resulting in 23 comparisons of lean mass changes were included in the final analysis. This abstract presents sub-analyses for comparisons with catabolic and anabolic stimuli, specifically ER and/or RT, respectively. Among all comparisons, protein intakes greater than the RDA attenuated lean mass loss after ER [0.41 kg (0.15, 0.67); WMD (95% CI), n = 15 comparisons], but did not influence lean mass change without ER [0.23 kg (−0.44, 0.89), n = 8]. Protein intakes greater than the RDA increased lean mass after RT [0.77 kg (0.23, 1.31), n = 3], but not influence change in lean mass without RT [0.29 kg (−0.04, 0.62, n = 20].

Conclusions

Protein intakes greater than the RDA positively influence changes in lean mass when adults are purposefully stressed by the catabolic stimulus of dietary energy restriction and/or the anabolic stimulus of resistance training. The RDA for protein is adequate for adults during non-stressed states.

Funding Sources

Purdue University Lynn Fellowship. No external funding was provided for this review.

The Protein Recommended Dietary Allowance Is Adequate to Retain Lean Body Mass: A Systematic Review and Meta-Analysis of Randomized Controlled Trials (P08-065-19)

Objectives

Classic short-term nitrogen balance research estimated that the Recommended Dietary Allowance (RDA) of 0.8 g protein/kg/d would be adequate to maintain whole-body nitrogen balance in 97.5% of the population. However, achieving whole-body nitrogen balance does not necessarily equate with tissue-specific amino acid (nitrogen) needs, for example in skeletal muscle. The objective of this systematic review and meta-analysis was to assess in weight-stable adults the effects of chronically consuming greater than the protein RDA, compared to the RDA, on whole-body composition.

Methods

Articles published through 2018 were identified with PubMed, Scopus, Cochrane, and CINAHL databases. Five articles with 7 comparisons were identified to be relevant through the databases and through screening previous published reviews. Two researchers independently screened the articles for eligible randomized controlled trials (RCTs) of parallel design that measured changes in body composition after ³6 wk of dietary control.

Results

There was significant heterogeneity in the effect sizes amongst the comparisons (I2  = 72.8%, χ2  = 22.1, P = 0.001). Consuming greater than the protein RDA did not differentially affect any of the changes in total body mass [0.07 kg (−0.75, 0.88); WMD, (95% CI), Random effects], fat mass [−0.65 kg (−1.33, 0.03)], or lean body mass [0.08 kg (−0.59, 0.75)].

Conclusions

These results from controlled feeding RCTs support adequacy of the protein RDA to retain lean body mass and indicate that protein intakes greater than the RDA do not promote morphological changes among weight-stable adults.

Funding Sources

Purdue University Graduate Lynn Fellowship. No external funding was provided for this review.

Protein Intakes Above the Recommended Dietary Allowance Reduce Fat Mass Irrespective of Energy Balance and Resistance Training Status: A Systematic Review and Meta-analysis (P08-056-19)

Objectives

The recommended dietary allowance (RDA) for protein of 0.8 g/kg/d is the current standard of dietary adequacy. Research assessing the effects of higher protein intakes on body composition often focus on changes in lean mass and use the RDA as the reference protein intake. However, it is important to also assess the importance of protein intake on fat mass, which relates to cardiometabolic health indices. Therefore, we sought to conduct a systematic review and meta-analysis to determine the effects of protein intakes greater than versus at the RDA on changes in whole body fat mass.

Methods

Three researchers independently screened 1531 articles published through August 2018 using PubMed, Scopus, CINAHL, and Cochrane databases, with additional articles identified through previously published review articles. Randomized-controlled, parallel studies at least 6 weeks long on apparently healthy adults (> = 19 years old) were eligible for data extraction.

Results

Data from 16 randomized-controlled, parallel studies resulting in 20 comparisons of fat mass changes were included in the final analysis. This abstract presents sub-analyses for comparisons with catabolic and anabolic stimuli, specifically energy restriction (ER) and/or resistance training (RT), respectively. Among all comparisons, consuming greater than the protein RDA resulted in greater fat mass change [–0.81 kg (–1.25, –0.37); WMD (95% CI), n = 20 comparisons]. The beneficial effect of greater protein intake on adiposity was apparent irrespective of energy or training status. Groups consuming greater than the RDA with ER lost more fat mass [–0.91 kg (–1.55, –0.28), n = 13], and groups consuming greater than the RDA without ER lost fat mass, while there was no reduction in groups consuming the RDA [–0.65 kg (–1.29, –0.05), n = 7]. Greater protein intake promoted fat mass loss with RT [–0.91 kg (–1.55, –0.28), n = 2] and without RT [–0.65 kg (–1.29, –0.05), n = 18].

Conclusions

These results support protein intakes greater than the RDA to reduce fat mass, irrespective of energy balance and resistance training status.

Funding Sources

No external funding was provided.

Is there long-term value of pathology scoring in immunoglobulin A nephropathy? A validation study of the Oxford Classification for IgA Nephropathy (VALIGA) update

Background

It is unknown whether renal pathology lesions in immunoglobulin A nephropathy (IgAN) correlate with renal outcomes over decades of follow-up.

Methods

In 1130 patients of the original Validation Study of the Oxford Classification for IgA Nephropathy (VALIGA) cohort, we studied the relationship between the MEST score (mesangial hypercellularity, M; endocapillary hypercellularity, E; segmental glomerulosclerosis, S; tubular atrophy/interstitial fibrosis, T), crescents (C) and other histological lesions with both a combined renal endpoint [50% estimated glomerular filtration rate (eGFR) loss or kidney failure] and the rate of eGFR decline over a follow-up period extending to 35 years [median 7 years (interquartile range 4.1–10.8)].

Results

In this extended analysis, M1, S1 and T1–T2 lesions as well as the whole MEST score were independently related with the combined endpoint (P < 0.01), and there was no effect modification by age for these associations, suggesting that they may be valid in children and in adults as well. Only T lesions were associated with the rate of eGFR loss in the whole cohort, whereas C showed this association only in patients not treated with immunosuppression. In separate prognostic analyses, the whole set of pathology lesions provided a gain in discrimination power over the clinical variables alone, which was similar at 5 years (+2.0%) and for the whole follow-up (+1.8%). A similar benefit was observed for risk reclassification analyses (+2.7% and +2.4%).

Conclusion

Long-term follow-up analyses of the VALIGA cohort showed that the independent relationship between kidney biopsy findings and the risk of progression towards kidney failure in IgAN remains unchanged across all age groups and decades after the renal biopsy.

Neonatal lupus in triplet pregnancy of a patient with undifferentiated connective tissue disease evolving to systemic lupus erythematosus

Pregnancy in patients suffering from undifferentiated connective tissue disease (UCTD) represents a risk situation for both the mother and the child. SSA/SSB autoantibodies can determine neonatal lupus (NL) in the foetus, regardless of the maternal disease. Furthermore, pregnancy increases the risk of flares and evolution to differentiated connective tissue disease (CTD). We report an uncommon case in which these complications occurred in a mother and in her foetuses. A 37-year-old woman affected by UCTD developed systemic lupus erythematosus (SLE) after her triplet pregnancy. The only manifestation of neonatal lupus we observed in the three newborns was SSA positivity associated with asymptomatic transient neutropenia.

Risk factors for a first thrombotic event in antiphospholipid antibody carriers. A multicentre, retrospective follow-up study

OBJECTIVES

To asses risk factors for a first thrombotic event in antiphospholipid antibody (aPL) positive carriers and evaluate the efficacy of prophylactic treatments.

METHODS

Recruitment criteria were age 18-65 years, no history of thrombosis, positivity for lupus anticoagulant and/or IgG/IgM anticardiolipin antibody (aCL) on > or =2 occasions at least 6 weeks apart. Demographic, laboratory and clinical parameters were collected at enrolment and at the time of the thrombotic event.

RESULTS

370 patients/subjects (mean (SD) age 34 (9.9) years) were analysed retrospectively for a mean (SD) follow-up of 59.3 (45.5) months. Thirty patients (8.1%) developed a first thrombotic event during follow-up. Hypertension and medium/high levels of IgG aCL were identified by multivariate logistic regression analysis as independent risk factors for thrombosis. Thromboprophylaxis during high-risk and long-term periods was significantly protective.

CONCLUSIONS

Hypertension or medium/high titres of IgG aCL are risk factors for a first thrombotic event in asymptomatic aPL carriers and primary prophylaxis is protective.

Knowledge of the Anomalies of the Big Central Veins Reduces the Morbidity during the Cannulation for Hemodialysis: Description of a Case of Persistent Left Superior Vena Cava and Revision of Literature

The persistence of a left superior vena cava is the result of a lack of an embryological involution of the left anterior cardinal vein. This anomaly is very rare: about 0.3% of the general population. Its incidence increases remarkably from 3–10% in those patients affected with congenital heart disease. Described herein is a case of persistent left superior vena cava, discovered by chance, following the placement of a central venous catheter for hemodialysis. A chest X-ray in projection back-forward showed the central venous catheter along the left sternal margin simulating a placement in the aorta artery. This clinical picture, as described in the literature, is often accompanied by other anatomical anomalies, in our case, by the congenital agenesis of a solitary pelvic kidney. In agreement with the literature and in contrast with what has been reported recently, we sustain that a central venous catheter placed, for any reason, in the persistent left superior vena cava must be removed immediately because it can induce hyperkinetic arrhythmia and cardiac arrest as in our case. Our case report should be a warning that lack of awareness of the anomalies of the big central veins can cause a rise in morbidity.

[Acute kidney failure and losartan: a recently observed event of antagonists of angiotensin II AT1 receptors]

Losartan is the first of a new category of drug that inhibits angiotensin II (ANG II) AT1 receptors antagonists. This drug lowers blood pressure by inhibiting the activity of ANG II and reduces proteinuria and progression of chronic renal failure (CRF). It seems therefore an extremely interesting drug. Aim of this study is to describe 3 cases of acute renal failure (ARF), occurred during therapy with losartan. None of the patients showed renal arteries stenosis or other predisposing factors for the development of ARF. In conclusion, we want pointed out that losartan could affect renal function in a similar way as angiotensin converting enzyme inhibitors (ACEI). We suggested that use of losartan in risk situations, like old age, preexiting CRF, stenosis of renal arteries, solitary kidney and diuretic therapy, should be carefully monitored as well as that of ACE I.

[Evaluation of urea recirculation and dialysis efficiency of central venous jugular catheters when the venous lumen is used as an arterial lumen]

BACKGROUND

The dual lumen internal jugular venous catheter has proven to be the most useful temporary vascular access for hemodialysis. According to this evidence it was decided to evaluate urea recirculation rate during hemodialysis performed by dual lumen internal jugular catheter (IJC) under normal condition (R1) and when the arterial lumen of the catheter is used as venous lumen, and the venous lumen as arterial lumen (R2).

METHODS

In 71 patients who underwent hemodialysis using a dual lumen IJC, urea recirculation rate was measured during a conventional bicarbonate hemodialysis, under normal condition R1 and during the experimental condition R2.

RESULTS

Urea recirculation rate < 5% was achieved for almost all patients under normal condition R1. In the different condition R2, urea recirculation rate increased in all patients, from an average value of 3.7 +/- 1.7 to 5.1 +/- 1.8 p < 0.0001. This increment was expected ut surprisingly low.

CONCLUSIONS

In conclusion during hemodialysis with dual lumen IJC efficient treatment can be provided in normal condition and also when the venous lumen is used as arterial lumen.

[Drugs used in the treatment of arterial hypertension in dialysis patients in the Piedmont. What correlations between personal and clinical data can be made from the registry data?]

The therapeutical approach to arterial hypertension in the general population is now relatively well classified, whereas it remains a controversial problem in dialytic patients. The aim of this study was to evaluate the antihypertensive drugs used in dialytic patients in Piedmont and to identify correlations with other personal and clinical data. The authors analysed the data in the Piedmont Dialysis and Transplant Register concerning new patients admitted to dialysis during the period 1990-1995 (2,664 patients at 31/12/1995) and 1,373 patients who began dialysis during the period 1990-1993. A study of the antihypertensive drugs using in single and combined therapy over the five-year period shows major variations in the 45-65 year-old age bracket (increased ACE-inhibitors in single therapy, 15.5-25.6%, increased vasodilators in combined therapy, 15.3-21%). In patients aged > or = 65 years old a slight increase was found in the use of beta-blockers in monotherapy. Antihypertensive drugs at the 1st control (1990-1995 entries) appeared to be stable over the five-year period. From the 1,373 patients who started dialysis in the period 1990-1993, with at least three subsequent controls, the authors selected those hypertensive or normotensive patients receiving ACE-inhibitor therapy (best survival in general population) and compared their survival with that of patients receiving alternative antihypertensive treatment. No significant differences were found. The stability of the antihypertensive drugs taken by these patients over the past 5 years backs the hypothesis of a greater attention paid by nephrologists to the introduction of new drugs, both because of the frequent onset of collateral effects and owing to the special pharmacokinetics present in dialytic patients.

Influence of the hydration state on blood pressure values in a group of patients on regular maintenance hemodialysis

The pathophysiology of hypertension in patients on renal replacement therapy is not yet clear, and the role of extracellular fluid overload is still a matter of debate. The main problem is the lack of techniques to determine the fluid state. Recently new noninvasive techniques have become available which make it possible to accurately determine the hydration state in these patients. We have studied the influence of the hydration state on interdialytic blood pressure in 45 patients: 21 (46.6%) using antihypertensive medication and 24 (53.4%) without antihypertensive medication. Total body water (TBW) was determined by bioelectrical impedance analysis performed just before a hemodialysis session. The TBW was then related to the fat-free mass calculated by the anthropometric method (aFFM) of Durnin. The hydration state was defined using the following formula: TBW/aFFM 100. Furthermore, for each patient the ideal TBW was calculated according to the Watson formula. The difference between TBW and ideal TBW was considered a further index of the hydration state. Ambulatory blood pressure monitoring was performed by using a Takeda 24200 recorder according to the Korotkoff method during the 24 h before the midweek hemodialysis session. Blood pressure monitoring showed a significant correlation with the hydration state of these patients. In conclusion, the hydration state seems to play a major role in interdialytic blood pressure control.

[Epidemiology and clinical course in hepatitis C-positive patients treated with dialysis in Piemonte. Work group of the RPDT]

The high prevalence of HCV positivity in dialysis patients has recently prompted several studies on this controversial subject. The aim of the study was an evaluation of HCV positivity and of influence on clinical outcome in 2,404 patients on dialysis in Piedmont (Northern Italy Region, about 4,400,000 inhab., 20 Dialysis Centers) at December 1993 (32.7% HCV-positive according to the Regional Registry of Dialysis and Transplantation). As expected, a strong correlation was found with time on dialysis (94.4% in patients with treatment follow-up > or = 20 years) and blood transfusions (41.3% HCV positivity in transfused patients versus 22.6% in not transfused ones; p < 0.0001). Dialysis in a hospital setting is confirmed as at high risk of infection, since HCV positivity was 19.6% in patients always treated by bicarbonate dialysis in hospital versus 8.9% in those treated only by CAPD (start of dialysis in 1992-1993). Despite the high prevalence of HCV positivity, however, death rates for liver disease and for all gastrointestinal causes are very low, regardless of HCV antibody status (1.2% in HCV positive versus 2.3% in HCV negative, NS). Whether this depends upon different clinical features of HCV infection in dialysis patients or merely deflects a relatively short follow-up will be matter of discussion in the future.

Monitoring of central venous dual-lumen catheter placement in haemodialysis: improvement of a technique for the practising nephrologist

Mismanagement in the placement of central venous catheter (CVC) may occur in up to 20% of cases. The catheter can be inadvertently placed in the contralateral brachiocephalic vein, the ipsi or contralateral internal jugular vein, and usually a thoracic radiograph is necessary to evaluate its location. We propose a technique first described by Serafini et al. to establish the position of a CVC by endocavitary electrocardiography (EC-ECG) and its employment in a large number of uraemic patients requiring haemodialysis. This technique uses the tip of the CVC as reference lead in a standard electrocardiograph. The best employment of this technique has been obtained by echotomographic visualization of the internal jugular vein executed just before transcutaneous puncture of the vessel. For 13 months we have successfully applied this technique in CVC placement in 81 patients requiring haemodialysis. In our opinion this method is a safe and simple technique that avoids the need for thoracic radiographs and time lost waiting for radiographs that prolong the start of the haemodialysis session. According to our experience, we confirm that the EC-ECG technique provides a method for ensuring compliance with Food and Drug Administration guidelines regarding catheter tip location in uraemic patients.

[Arterial hypertension secondary to Conn's disease: an infrequent pathology in nephrology. Report of a clinical case]

In this work we describe a case of Conn's syndrome caused by a suprarenal adenoma in a sixty-one year female. The patient had come to our observation because of severe hypertension and hypokalemia. Primary aldosteronism resulting from the secretion of excessive amounts of aldosterone caused by autonomous hyperfunction of the adrenal cortex usually by a solitary adenoma. In most series of unselected patients, it is found in fewer than 0.5% of hypertensives. In our study we demonstrated the circadian changes of arterial blood pressure but we failed to demonstrate the presence of hypertrophic cardiomyopathy as recently emphasized in the literature. Regardless of its rarity, primary aldosteronism is a fascinating disease, protean in its manifestations, logical in its pathophysiology.

[Protein metabolism and nutritional status in hemodialysis]

We have studied protein metabolism and nutritional status in a group of patients in regular dialysis treatment. In forty-five patients (mean age 58 +/- 11 yr), undergoing maintenance hemodialysis we have measured protein (DPI) ad caloric (CI) intake by a three-day dietary recall. Protein catabolic rate (PCR) using the urea kinetic model (Gotch' variable volume), anthopometric parameters such as weight, height, midarm circumference, skinfold thickness, midarm muscle circumference (AMC), midarm muscle area (AMA), total muscle mass (TMM) and the percentage of body fat were measured as well. PCR was weakly correlated with DPI. TMM showed a direct relationship with DPI and correlated inversely with UNA/NI (Urea Nitrogen Appearance/Nitrogen Intake). 18% of patients were underweight; 17% showed a decrease of AMA. TMM was inversely correlated with total hospitalization days. There were no significant variations of the examined parameters in a year later evaluation. In our experience TMM is the parameter which better correlates with clinical findings.

[Nutritional evaluation of a group of patients with terminal uremia treated with an artificial diet]

The effects of a low protein died supplemented with essential aminoacids (EAA) and keto analogues (KA) on nutritional status have been evaluated in eight chronic uremic patients. After six months of diet, no significant reduction of protidemia (changing from 6.66 +/- 0.5 g/dl to 6.61 +/- 0.8 g/dl) and albuminemia (changing from 4.13 +/- 0.4 g/dl to 3.90 +/- 0.5 g/dl) was observed. Moreover, neither body weight (changing from 70.437 +/- 8.03 kg to 69.500 +/- 8.26 kg) nor total muscular mass (changing from 25.26 +/- 3.83 kg to 25.36 +/- 5.74 kg) showed significant variations. Therefore, in our experience, low protein diet supplement with EAA and KA has not induced any deterioration of nutritional status.

The fate of leached di-(2-ethylhexyl)-phthalate (DEHP) in patients on chronic haemodialysis

The fate of the plasticiser di-(2-ethylhexyl)-phthalate and/or its metabolites, phthalic acid esters (PAE), in 12 patients on chronic haemodialysis was studied. The total amount of PAE retained by the patients was estimated by monitoring the plasma concentrations from the inflow and outflow tubes of the dialyzer during 4-h dialysis sessions. There was an estimated uptake of 46 mg of PAE during a single dialysis session. The values for a volumetric factor (Vf) related to the increment in plasma PAE concentrations were found to increase during the first hour of treatment (72 litres at steady-state), and then to progressively decrease. The changes in the kinetic parameters during the dialysis session were grouped into three phases according to the fate of the plasticiser in the patient. We also monitored the plasma concentrations of PAE in the same patients for 40 days during dialysis with another kind of plasticised (tri-(2-ethylhexyl)-trimellitate [TOTM]) tubes. The PAE concentrations were similar to those found in healthy humans after about 5 weeks.

[Humoral markers of iron status in patients on maintenance hemodialysis]

In forty-nine patients on regular dialysis treatment (RDT) we evaluated following parameters for a period of twenty-four months: serum ferritin (SF), transferrin, T.I.B.C. percental saturation (Fe/TIBC%), haemoglobin (Hb). Twenty-five patients had received more than 5 g intra-venous iron or several blood transfusions, before the beginning of the study, while the other twenty four patients had never received iron treatment nor transfusions. Serum ferritin and Fe/TIBC% proved to be a good estimate of iron stores in RDT patients. In fact both parameters showed significantly higher levels in iron loaded patients than in never treated patients. Furthermore, in patients who no longer received iron loads during the study period, both SF and Fe/TIBC% showed a significant decrease, without changes in haematologic values. This study demonstrated that oral ferritinic iron (40 mg/day for 6 months) doesn't increase either SF and Fe/TIBC% levels, or modifies haematologic values.

[Acute renal insufficiency caused by diflunisal. Description of a case]

A case of kidney failure in a patient with cirrhosis of the liver in the ascitic stage after treatment of a non-steroid anti-inflammatory drug, diflunisal, is reported. The pathogenesis of the kidney impairment, quickly reversed by withdrawal of the drug, is attributed to pharmacological inhibition of cyclo-oxygenase and prostaglandin synthesis with consequent alterations of intrarenal haemodynamics and renal blood flow.

[Effects of long-term treatment with L-carnitine on dyslipemia in hemodialysis patients]

The effect of long-term intravenous administration of L-carnitine on the lipid pattern of 18 patients on intermittent haemodialysis has been evaluated. Serum levels of carnitine were assayed at the beginning and after 4 months of treatment: no significant change was observed. At the end of our investigation, we found a significant reduction of HDL-cholesterol and a significant increase of triglyceride levels, compared with basal values. On the contrary cholesterol levels did not change. Five of the patients though behaved as responders to the treatment: their triglyceride levels decrease while their carnitine values rose significantly. The Authors discuss the therapeutic importance of L-carnitine and its possible influence on dyslipaemia of uremic haemodialysed patients.

[Nephrotoxicity of contrast media for urography in patients with chronic renal insufficiency]

The incidence of nephrotoxicity caused by intravenous pielography (IVP) contrast media was retrospectively evaluated in 42 patients with chronic renal failure. In 14 patients renal function was acutely impaired after IVP. In most cases the dysfunction was only temporary; in 3 cases permanent damage was induced, one of which required dialytic treatment. In the cases described there appears to be no correlation between the degree of renal failure and the incidence of nephrotoxicity but the former is clearly linked to the severity of the nephrotoxic response.

Does renal tubular dysfunction account for the enhanced CAm/CCr ratio in acute pancreatitis?

To verify whether renal tubular dysfunction may account for the CAm/CCr enhancement in acute pancreatitis (AP), we have measured the renal excretion of amylase, lysozyme, and gamma-glutamyl-transpeptidase (GGTP) in 22 patients with AP and in 8 with acute tubular necrosis. While the CAm/CCr ratio was elevated in most patients with AP, the CLys/CCr ratio fell within the normal range in 60% of these patients. The subdivision of patients with AP in subgroups with elevated and normal CLys/CCr ratios revealed a mean CAm/CCr not statistically different. Moreover, no correlation was present in AP between amylase vs. both lysozyme and GGTP clearances. These data suggest that tubular dysfunction does occur in some but not in all the patients with AP and seems not to play a major role in the pathogenesis of the increased CAm/CCr ratio in this condition.

Amylase to creatine clearance ratio in renal diseases

In order to assess to what extent glomerular or tubular function is involved in the renal handling of amylase and the lysozyme to creatine clearance ratios (CAm/CCr and CLys/CCr) were evaluated in 22 healthy volunteers and in 71 patients with different renal diseases. In normal controls, the mean CAm/CCr was 2.55 +/-1.54 SD, with an upper normal limit of 5.56. A normal ratio was found in patients with glomerulonephritis, with or without a nephrotic syndrome, and in patients with pyelonephritis. A significantly elevated ratio (P less than 0.001) was instead found in patients with uremia and in patients with uremia and in patients with either chronic or acute tubular damage. The CLus/CCr ratio was elevated in all the groups, except in patients with glomerulonephritis and minimal proteinuria. These results show that in humans, as in animals, the amylase filtered load undergoes partial tubular reabsorption. In renal diseases, an increase of the CAm/CCr is caused by either a marked reduction of functioning nephrons or a severe tubular damage, while the glomerular permeability does not seem to be involved. Some other mechanism is probably involved in the elevation of the CAm/CCr during acute pancreatitis.