Effect of low-protein intake on all-cause mortality in subjects with an estimated glomerular filtration rate higher than 60 mL/min/1.73 m2 with or without albuminuria

BACKGROUND

We aimed to investigate the effect of a low-protein intake on all-cause mortality in subjects with an estimated glomerular filtration rate (eGFR) ≧60 mL/min/1.73 m² with or without albuminuria using data from the National Health and Nutrition Examination Survey (NHANES).

METHODS

We analysed participants in the NHANES from 2003 to 2010. We excluded participants with an eGFR less than 60 mL/min/1.73 m² from the analyses. Low-protein intake was defined as a protein intake of less than 0.8 g/kg/day. The Healthy Eating Index 2010 was used to assess diet quality. The vital status of all participants in the NHANES was determined by linking to the National Death Index through the end of 2011. The hazard ratios (HRs) for the association of low-protein intake and mortality were determined using weighted Cox proportional hazards regression models.

RESULTS

A total of 7730 participants were included in the analyses. After a median follow up of 4.7 years, 462 participants died. A low-protein intake was associated with a higher risk of mortality (HRs 1.394, 95% CI 1.121-1.734, P = .004) with adjustment for diet quality and relevant risk factors. The higher risk of mortality associated with a low-protein intake was consistent in subjects with or without albuminuria (P interaction .280).

CONCLUSION

A protein intake of less than 0.8 g/kg/day was associated with a higher risk of mortality in subjects with an eGFR ≧60 mL/min/1.73 m² , irrespective of whether they had albuminuria.

Development and validation of a short food questionnaire to screen for low protein intake in community-dwelling older adults: The Protein Screener 55+ (Pro55+)

In old age, sufficient protein intake is important to preserve muscle mass and function. Around 50% of older adults (65+ y) consumes ≤1.0 g/kg adjusted body weight (BW)/day (d). There is no rapid method available to screen for low protein intake in old age. Therefore, we aimed to develop and validate a short food questionnaire to screen for low protein intake in community-dwelling older adults. We used data of 1348 older men and women (56–101 y) of the LASA study (the Netherlands) to develop the questionnaire and data of 563 older men and women (55–71 y) of the HELIUS study (the Netherlands) for external validation. In both samples, protein intake was measured by the 238-item semi-quantitative HELIUS food frequency questionnaire (FFQ). Multivariable logistic regression analysis was used to predict protein intake ≤1.0 g/kg adjusted BW/d (based on the HELIUS FFQ). Candidate predictor variables were FFQ questions on frequency and amount of intake of specific foods. In both samples, 30% had a protein intake ≤1.0 g/kg adjusted BW/d. Our final model included adjusted body weight and 10 questions on the consumption (amount on average day or frequency in 4 weeks) of: slices of bread (number); glasses of milk (number); meat with warm meal (portion size); cheese (amount and frequency); dairy products (like yoghurt) (frequency); egg(s) (frequency); pasta/noodles (frequency); fish (frequency); and nuts/peanuts (frequency). The area under the receiver operating characteristic curve (AUC) was 0.889 (95% CI 0.870–0.907). The calibration slope was 1.03 (optimal slope 1.00). At a cut-off of ≤0.8 g/kg adjusted BW/d, the AUC was 0.916 (96% CI 0.897–0.936). Applying the regression equation to the HELIUS sample, the AUC was 0.856 (95% CI 0.824–0.888) and the calibration slope 0.92. Regression coefficients were therefore subsequently shrunken by a linear factor 0.92. To conclude, the short food questionnaire (Pro⁵⁵⁺) can be used to validly screen for protein intake ≤1.0 g/kg adjusted BW/d in community-dwelling older adults. An online version can be found at www.proteinscreener.nl. External validation in other countries is recommended.

[Protein deficiency - a rare nutrient deficiency]

There is a widespread myth that we have to be careful about what we eat so that we do not cause protein deficiency. We know today that it is virtually impossible to design a calorie-sufficient diet, whether it is based on meat, fish, eggs, various vegetarian diets or even unprocessed whole natural plant foods, which is lacking in protein and any of the amino acids. The body is capable of taking incomplete proteins and making them complete by utilizing the amino acid recycling mechanism. The majority of amino acids absorbed from the intestinal tract are derived from recycled body protein. Research shows that high levels of animal protein intake may significantly increase the risk of premature mortality from all causes, among them cardiovascular diseases, cancer and type 2 diabetes.

Parenteral nutrition in intensive care patients: medicoeconomic aspects

PURPOSE OF REVIEW

Parenteral nutrition (PN) alone or as supplemental parenteral nutrition (SPN) has been shown to prevent negative cumulative energy balance, to improve protein delivery and, in some studies, to reduce infectious morbidity in ICU patients who fail to cover their needs with enteral nutrition (EN) alone.

RECENT FINDINGS

The optimization of energy provision to an individualized energy target using either early PN or SPN within 3-4 days after admission has recently been reported to be a cost-saving strategy mediated by a reduction of infectious complications in selected intensive care patients.

SUMMARY

EN alone is often insufficient, or occasionally contraindicated, in critically ill patients and results in growing energy and protein deficit. The cost benefit of using early PN in patients with short-term relative contraindications to EN has been reported. In selected patients SPN has been associated with a decreased risk of infection, a reduced duration of mechanical ventilation, a shorter stay in the ICU. Altogether four studies have investigated the costs associated with these interventions since 2012: two of them from Australia and Switzerland have shown that optimization of energy provision using SPN results in cost reduction, conflicting with other studies. The latter encouraging findings require further validation.

The relevance of dietary protein after bariatric surgery: what do we know?

PURPOSE OF REVIEW

The growing obesity epidemic is associated with an increased demand for bariatric surgery with Roux-en-Y Gastric Bypass and Sleeve Gastrectomy as the most widely performed procedures. Despite beneficial consequences, nutritional complications may arise because of anatomical and physiological changes of the gastrointestinal tract. The purpose of this review is to provide an update of the recent additions to our understanding of the impact of bariatric surgery on the intake, digestion and absorption of dietary protein.

RECENT FINDINGS

After bariatric surgery, protein intake is compromised because of reduced gastric capacity and aversion for certain foods. A minority of patients reaches the recommended protein intake of minimal 60 g per day, which results in the loss of fat-free mass rather than the desired loss of fat mass. Despite inadequate protein intake, protein digestion and absorption do not seem to be impaired suggesting that other mechanisms could counteract the reduced secretion of digestive enzymes and their delayed inlet.

SUMMARY

After bariatric surgery, protein supplementation or diet enrichment could attribute to achieve the minimal recommended protein intake and benefit the amount and composition of postoperative weight loss.

Protein malnutrition after weaning disrupts peripheral clock and daily insulin secretion in mice

Changes in nutritional state may alter circadian rhythms through alterations in expression of clock genes. Protein deficiency has a profound effect on body metabolism, but the effect of this nutrient restriction after weaning on biological clock has not been explored. Thus, this study aims to investigate whether the protein restriction affects the daily oscillation in the behavior and metabolic rhythms, as well as expression of clock genes in peripheral tissues. Male C57BL/6 J mice, after weaning, were fed a normal-protein (NP) diet or a low-protein (LP) diet for 8 weeks. Mice fed an LP diet did not show difference in locomotor activity and energy expenditure, but the food intake was increased, with parallel increased expression of the orexigenic neuropeptide Npy and disruption of the anorexigenic Pomc oscillatory pattern in the hypothalamus. LP mice showed disruption in the daily rhythmic patterns of plasma glucose, triglycerides and insulin. Also, the rhythmic expression of clock genes in peripheral tissues and pancreatic islets was altered in LP mice. In pancreatic islets, the disruption of clock genes was followed by impairment of daily glucose-stimulated insulin secretion and the expression of genes involved in exocytosis. Pharmacological activation of REV-ERBα could not restore the insulin secretion in LP mice. The present study demonstrates that protein restriction, leading to development of malnutrition, alters the peripheral clock and metabolic outputs, suggesting that this nutrient provides important entraining cues to regulate the daily fluctuation of biological clock.

Peculiarities of the free radical processes in rat liver mitochondria under toxic hepatitis on the background of alimentary protein deficiency

The rate of superoxide anion radical, hydroxyl radical and hydrogen peroxide generation, the level of oxidative modification of mitochondrial proteins in the liver of rats with toxic hepatitis was investigated on the background of alimentary protein deficiency. We did not find significant increases of the intensity of free radical processes in liver mitochondria of rats maintained on the protein-deficient ration. The most significant intensification of free radical processes in liver mitochondria is observed under the conditions of toxic hepatitis, induced on the background of alimentary protein deprivation. Under these conditions the aggravation of all studied forms of reactive oxygen species generation was observed in liver mitochondria. The generation rates were increased as follows: O2 – by 1.7 times, Н2О2 – by 1.5 times, •ОН – practically double on the background of accumulation of oxidized mitochondria-derived proteins. The established changes in thiol groups’ redox status of respiratory chain proteins insoluble in 0.05 M sodium-phosphate buffer (pH 11.5), and changes of their carbonyl derivatives content may be considered as one of the regulatory factors of mitochondrial energy-generating function.

Nutritional and Protein Deficiencies in the Short Term following Both Gastric Bypass and Gastric Banding

BACKGROUND

The number of morbidly obese patients undergoing bariatric surgery (BS) has increased dramatically in recent years. Therefore, monitoring food intake and its consequences in terms of nutritional status is necessary to prevent nutritional deficiencies. The aim of this study was to analyze the effect of food restriction on nutritional parameters in the short-term (≤3 months) period after BS in morbid obesity.

METHOD

In a prospective study, we followed 22 obese women who underwent Roux-en-Y gastric bypass (GBP) or adjustable gastric banding (AGB) at baseline (T0) and 1 (T1) and 3 (T3) months after surgery. We evaluated food intake, nutrient adequacy and serum concentrations of vitamins and minerals known to be at risk for deficiency following BS.

RESULTS

Before surgery, we observed suboptimal food intakes, leading to a risk of micronutrient deficiencies. Serum analysis confirmed nutritional deficiencies for iron and thiamine for 27 and 23% of the patients, respectively. The drastic energy and food reduction seen in the short term led to very low probabilities of adequacy for nutrients equivalent across both surgeries. Serum analysis demonstrated a continuous decrease in prealbumin during the follow-up, indicating mild protein depletion in 21 and 57% of GBP patients and 50 and 63% of AGB patients, respectively, at T1 and T3. Regarding vitamins and minerals, systematic supplementation after GBP prevented most nutritional deficiencies. By contrast, AGB patients, for whom there is no systematic supplementation, developed such deficiencies.

CONCLUSIONS

Our results suggest that cautious monitoring of protein intake after BS is mandatory. Furthermore, AGB patients might also benefit from systematic multivitamin and mineral supplementation at least in the short term.

Clinical outcomes of duodenal switch with a 200-cm common channel: a matched, controlled trial

BACKGROUND

Biliopancreatic diversion with duodenal switch (BPD-DS) with a 100-cm common channel has been our treatment of choice for morbid obesity since the early 1990s. This procedure offers excellent long-term weight loss but can be associated with significant side effects.

OBJECTIVES

To assess the effect on clinical and nutritional parameters of increasing the common channel to 200 cm.

SETTINGS

University-affiliated tertiary care center.

METHODS

Patients who underwent a BPD-DS with a 200-cm common channel (study group, n = 36) were matched 1:1 for age, sex, body mass index (BMI), and main co-morbidities with patients who underwent a BPD-DS with a 100-cm common channel (control group). The strict alimentary limb was 150 cm in both groups.

RESULTS

The mean age was 55±9 versus 53±7 years (P = .3), with 50% women and a BMI of 49±8 kg/m(2) versus 50±6 kg/m(2) (P = .9). Follow-up rate was 97%, with a minimum follow-up of 3 years. There were no significant differences in the remission rate of major co-morbidities between the 2 groups. At 3 years, the excess weight loss was 61±22% versus 68±18% (P = .18) and the total weight loss was 33±11% versus 38±9% (P = .055) in the study group versus control group, respectively. The study group had a lower incidence of severe protein deficiency (11% versus 19%, P = .3) and hyperparathyroidism (17.1% versus 35.3%, P = .17); required a lower amount of vitamins A and D (P<.05); and had a decreased number of daily bowel movements (2.0 versus 2.9, P = .03).

CONCLUSION

In this population, BPD-DS with a 200-cm common channel offered similar remission rate of co-morbidities compared with standard BPD-DS. It was associated with similar weight loss at nadir, followed by a more significant weight regain. It might yield a lower rate of nutritional complications. Long-term randomized data are needed to detect other potential advantages.

Leucine restores murine hepatic triglyceride accumulation induced by a low-protein diet by suppressing autophagy and excessive endoplasmic reticulum stress

Although it is known that a low-protein diet induces hepatic triglyceride (TG) accumulation in both rodents and humans, little is known about the underlying mechanism. In the present study, we modeled hepatic TG accumulation by inducing dietary protein deficiency in mice and aimed to determine whether certain amino acids could prevent low-protein diet-induced TG accumulation in the mouse liver. Mice fed a diet consisting of 3 % casein (3C diet) for 7 days showed hepatic TG accumulation with up-regulation of TG synthesis for the Acc gene and down-regulation of TG-rich lipoprotein secretion from hepatocytes for Mttp genes. Supplementing the 3 % casein diet with essential amino acids, branched-chain amino acids, or the single amino acid leucine rescued hepatic TG accumulation. In the livers of mice fed the 3 % casein diet, we observed a decrease in the levels of the autophagy substrate p62, an increase in the expression levels of the autophagy marker LC3-II, and an increase in the splicing of the endoplasmic reticulum (ER) stress-dependent Xbp1 gene. Leucine supplementation to the 3 % casein diet did not affect genes related to lipid metabolism, but inhibited the decrease in p62, the increase in LC3-II, and the increase in Xbp1 splicing levels in the liver. Our results suggest that ER stress responses and activated autophagy play critical roles in low-protein diet-induced hepatic TG accumulation in mice, and that leucine suppresses these two major protein degradation systems. This study contributes to understanding the mechanisms of hepatic disorders of lipid metabolism.

[NADH:ubiquinone reductase and succinate dehydrogenase activity in the liver of rats with acetaminophen-induced toxic hepatitis on the background of alimentary protein deficiency]

The ratio between the redox forms of the nicotinamide coenzymes and key enzymatic activity of the I and II respiratory chain complexes in the liver cells mitochondria of rats with acetaminophen-induced hepatitis under the conditions of alimentary deprivation of protein was studied. It was estimated, that under the conditions of acute acetaminophen-induced hepatitis of rats kept on a low-protein diet during 4 weeks a significant decrease of the NADH:ubiquinone reductase and succinate dehydrogenase activity with simultaneous increase of the ratio between redox forms of the nicotinamide coenzymes (NAD+/NADH) is observed compared to the same indices in the liver cells of animals with experimental hepatitis kept on the ration balanced by all nutrients. Results of research may become basic ones for the biochemical rationale for the approaches directed to the correction and elimination of the consequences of energy exchange in the toxic hepatitis, induced on the background of protein deficiency.

[SURGICAL COMPLICATIONS IN ACUTE POISONING AND PROTEIN--ENERGY DYSFUNCTION]

The article presents a review of acute surgical pathology and the frequency of its occurrence, complicating alcohol poisoning, cauterizing liquids, narcotic and psychotropic drugs and acute emerging metabolic (protein-energy). The development of surgical complications in poisoning was observed in patients in severe and very severe condition and is accompanied by a sharp increase in mortality (75%) and severe energy dysfunction. The most diverse and difficult flowing surgical complications were encountered in alcohol poisoning and cauterizing liquids.

Physiological slowing and upregulation of inhibition in cortex are correlated with behavioral deficits in protein malnourished rats

Protein malnutrition during early development has been correlated with cognitive and learning disabilities in children, but the neuronal deficits caused by long-term protein deficiency are not well understood. We exposed rats from gestation up to adulthood to a protein-deficient (PD) diet, to emulate chronic protein malnutrition in humans. The offspring exhibited significantly impaired performance on the 'Gap-crossing' (GC) task after reaching maturity, a behavior that has been shown to depend on normal functioning of the somatosensory cortex. The physiological state of the somatosensory cortex was examined to determine neuronal correlates of the deficits in behavior. Extracellular multi-unit recording from layer 4 (L4) neurons that receive direct thalamocortical inputs and layers 2/3 (L2/3) neurons that are dominated by intracortical connections in the whisker-barrel cortex of PD rats exhibited significantly low spontaneous activity and depressed responses to whisker stimulation. L4 neurons were more severely affected than L2/3 neurons. The response onset was significantly delayed in L4 cells. The peak response latency of L4 and L2/3 neurons was delayed significantly. In L2/3 and L4 of the barrel cortex there was a substantial increase in GAD65 (112% over controls) and much smaller increase in NMDAR1 (12-20%), suggesting enhanced inhibition in the PD cortex. These results show that chronic protein deficiency negatively affects both thalamo-cortical and cortico-cortical transmission during somatosensory information processing. The findings support the interpretation that sustained protein deficiency interferes with features of cortical sensory processing that are likely to underlie the cognitive impairments reported in humans who have suffered from prolonged protein deficiency.

Treatment of metabolic syndrome by combination of physical activity and diet needs an optimal protein intake: a randomized controlled trial

BACKGROUND

The recommended dietary allowance (RDA) for protein intake has been set at 1.0-1.3 g/kg/day for senior. To date, no consensus exists on the lower threshold intake (LTI = RDA/1.3) for the protein intake (PI) needed in senior patients ongoing both combined caloric restriction and physical activity treatment for metabolic syndrome. Considering that age, caloric restriction and exercise are three increasing factors of protein need, this study was dedicated to determine the minimal PI in this situation, through the determination of albuminemia that is the blood marker of protein homeostasis.

METHODS

Twenty eight subjects (19 M, 9 F, 61.8 ± 6.5 years, BMI 33.4 ± 4.1 kg/m²) with metabolic syndrome completed a three-week residential programme (Day 0 to Day 21) controlled for nutrition (energy balance of -500 kcal/day) and physical activity (3.5 hours/day). Patients were randomly assigned in two groups: Normal-PI (NPI: 1.0 g/kg/day) and High-PI (HPI: 1.2 g/kg/day). Then, patients returned home and were followed for six months. Albuminemia was measured at D0, D21, D90 and D180.

RESULTS

At baseline, PI was spontaneously 1.0 g/kg/day for both groups. Albuminemia was 40.6 g/l for NPI and 40.8 g/l for HPI. A marginal protein under-nutrition appeared in NPI with a decreased albuminemia at D90 below 35 g/l (34.3 versus 41.5 g/l for HPI, p < 0.05), whereas albuminemia remained stable in HPI.

CONCLUSION

During the treatment based on restricted diet and exercise in senior people with metabolic syndrome, the lower threshold intake for protein must be set at 1.2 g/kg/day to maintain blood protein homeostasis.

High-carbohydrate/low-protein-induced hyperinsulinemia does not improve protein balance in children after cardiac surgery

OBJECTIVE

In pediatric cardiac surgery, fluid-restricted low-protein (LoProt) diets account for cumulative protein deficits with increased morbidity. In this setting, we aimed to inhibit proteolysis by a high-carbohydrate (HiCarb)-intake-induced hyperinsulinemia and improve protein balance.

METHODS

The effect of a HiCarb/LoProt (glucose 10 mg · kg(-1) · min(-1)/protein 0.7 g · kg(-1) · d(-1)) versus a normal-carbohydrate (NormCarb)/LoProt (glucose 7.5 mg · kg(-1) · min(-1)/protein 0.3 g · kg(-1) · d(-1)) enteral diet on whole-body protein breakdown and balance was compared in a prospective, randomized, single-blinded trial in 24 children after cardiac surgery. On the second postoperative day, plasma insulin and amino acid concentrations, protein breakdown (endogenous rate of appearance of valine), protein synthesis (non-oxidative disposal of valine), protein balance, and the rate of appearance of urea were measured by using an isotopic infusion of [1-(13)C]valine and [(15)N(2)]urea.

RESULTS

The HiCarb/LoProt diet led to a serum insulin concentration that was three times higher than the NormCarb/LoProt diet (596 pmol/L, 80-1833, and 198 pmol/L, 76-1292, respectively, P = 0.02), without differences in plasma glucose concentrations. There were no differences in plasma amino acid concentrations, non-oxidative disposal of valine, and endogenous rate of appearance of valine between the groups, with a negative valine balance in the two groups (-0.65 μmol · kg(-1) · min(-1), -1.91 to 0.01, and -0.58 μmol · kg(-1) · min(-1), -2.32 to -0.07, respectively, P = 0.71). The serum cortisol concentration in the HiCarb/LoProt group was lower compared with the NormCarb/LoProt group (204 nmol/L, 50-544, and 532 nmol/L, 108-930, respectively, P = 0.02).

CONCLUSION

In children with fluid restriction after cardiac surgery, a HiCarb/LoProt diet compared with a NormCarb/LoProt diet stimulates insulin secretion but does not inhibit proteolysis further and therefore cannot be advocated for this purpose.

Nitrogen balance, protein loss, and the open abdomen

OBJECTIVE

Goal-directed nutritional support is essential to improving morbidity and mortality. Open abdominal decompression is similarly crucial to the successful treatment of intra-abdominal hypertension and abdominal compartment syndrome. The open abdomen, however, places the patient at risk for potentially significant fluid, electrolyte, and presumably protein losses from the exposed viscera. Although nutritional protein assessments are frequently utilized to measure urinary nitrogen, these calculations do not consider the loss of protein from the open abdomen. We hypothesize that accurate assessment of nitrogen balance in the patient requiring an open abdomen must include either a measurement or estimation of abdominal fluid nitrogen loss.

DESIGN

Prospective, observational cohort study.

SETTING

Adult surgical/trauma intensive care unit of a level I trauma center.

PATIENTS

Surgical/trauma patients requiring laparotomy.

INTERVENTIONS

Serial 24-hr collections of urine and abdominal fluid protein were performed to characterize abdominal fluid protein loss and evaluate the clinical effect of accounting for abdominal fluid nitrogen as part of nitrogen balance calculations.

MEASUREMENTS AND MAIN RESULTS

Nitrogen intake correlates with urinary nitrogen loss but not with abdominal fluid nitrogen loss. Abdominal fluid nitrogen loss is significant and remains relatively stable in the early postoperative period. Nutritional calculations that fail to account for abdominal fluid nitrogen loss significantly overestimate actual nitrogen balance by an average of 3.5 g/24 hrs.

CONCLUSIONS

The open abdomen represents a significant source of protein/nitrogen loss in the critically ill. Failure to account for this loss in nutritional calculations may lead to underfeeding and inadequate nutritional support with a direct effect on patient outcome. Although direct measurement of abdominal fluid protein loss may be optimal, an estimate of 2 g of nitrogen per liter of abdominal fluid output should be included in the nitrogen balance calculations of any patient with an open abdomen.

Review: long-term impact of bariatric surgery on body weight, comorbidities, and nutritional status

CONTEXT

The number of patients who undergo Roux-en-Y gastric bypass (RYGB) and gastric banding (GB) surgeries has increased dramatically over the past decade, yet the long-term impact of these surgeries on body weight, comorbidities, and nutritional status remains unclear, as do the mechanisms of weight regain.

EVIDENCE ACQUISITION

The articles were found via PubMed searches. To review the impact of bariatric surgery on weight maintenance and comorbidities, only articles with a postoperative follow-up of 3 yr or longer were included. The articles on nutritional status had a follow-up of 12 months or longer.

CONCLUSIONS

RYGB and GB surgeries lead to substantial weight loss in individuals with morbid obesity. However, significant weight regain occurs over the long term, and according to the only well-designed prospective controlled study, the improvement in comorbidities associated with weight loss mitigates in the long term on weight regain. There is some evidence from a retrospective study that RYGB surgery is associated with a modest decrease in long-term mortality. These results remain to be substantiated by well-designed, long-term, randomized and prospective controlled studies. The mechanisms that lead to weight regain need to be further examined and may include increase in energy intake due to enlargement of stoma and adaptive changes in the levels of gut and adipocyte hormones such as ghrelin and leptin, which regulate energy intake; decrease in physical activity; changes in energy expenditure; and other factors. In addition to weight regain, RYGB surgery is associated with frequent incidence of iron, vitamin B12, folate, calcium, and vitamin D deficiency, which requires regular supplementation and monitoring.

Biliopancreatic diversion. Clinical experience

AIM

Biliopancreatic diversion (BPD) has been accepted as an effective surgical treatment of morbid obesity. The paper presents the results of a personal clinical experience with this procedure, with special focus on the quality of life.

METHODS

From January 1, 1992 to June 30, 2002, 122 patients (F/M: 108/14, mean age: 40.2 years, range 21-61) underwent BPD. Mean preoperative body weight was 122.4 kg (range 91-200), with a mean Body Mass Index of 49.1 kg/m2 (range 38-78). Three of these patients were converted from a previous vertical banded gastroplasty to BPD (1 patients with stomach preservation). After at least a 36-month follow-up, 10 patients underwent abdominal dermolipectomy (8 associated to incisional hernia repair, 1 associated to thigh dermolipectomy).

RESULTS

Mean postoperative hospital stay was 12 days (range: 11-30). Follow-up is currently in progress in all patients. Weight loss of initial overweight was 75% in 88 patients with a 36-month follow-up, with excellent long-term weight maintenance. Protein deficiency was the main specific complication, encountered in 6 patients (4.9%). Beneficial effects, other than those consequent to weight loss, included permanent normalization of serum cholesterol and glucose without any medication and on a totally free diet. Almost 80% of the patients reported an improvement in their self-esteem, physical activity, work condition and social life.

CONCLUSIONS

This clinical experience supports the effectiveness and safety of BPD, despite some criticism. The small number of side effects and complications, the excellent weight loss and the recovery of most co-morbidity leads to a great improvement in quality of life.

Effects of protein deficiency induced by raw soy with and without sucrose on dentine formation and dentinal caries in young rats

OBJECTIVES

The effects of protein deficiency and sucrose on formation and mineralization of dentine and dental caries in the molars of young rats were investigated.

MATERIALS AND METHODS

Two groups of weaning Wistar rats received raw soy flour to induce protein deficiency with sucrose or starch as the carbohydrate source; the other two groups received skim milk powder as the protein source with sucrose or starch as the carbohydrate source. At the onset, tetracycline was injected to mark the dentine formed at that moment. After 6 weeks, lower molars were sectioned sagittally, and the areas of dentine formation and dentinal caries developed during the experiment were quantified separately in the first and second molars. Dental caries was also classified according to Schiff's reaction. Calcium (Ca), phosphorus (P) and total mineral elements were analyzed using an electron probe microanalyzer.

RESULTS

Rats in both protein-deficient groups and normal protein sucrose group had significantly larger areas of dentine formed compared with rats fed with normal protein starch diet. Ca, P and total mineral elements in dentine were significantly reduced by normal protein sucrose diet. P content was significantly reduced in dentine of rats in protein-deficient sucrose group. Rats in normal protein sucrose group had significantly more and larger dentinal caries lesions than in any other group.

CONCLUSION

This study suggests that protein deficiency induced by soy prevents the progression of dental caries even in highly cariogenic environment.

[Assessment of diet of students from Orenburg region]

The article this research is devoted to the Orenburg student youth diet. The revealed deficiency of major nutrients (protein, fats and especially carbohydrates), as vitamins (C, PP, E, D, B groups) and analysis of diet ration concerning basis nourishing components, vitamins, macro- micro elements (Zn, Cu, I, Cr, Se).

Macronutrient intakes as determinants of dietary protein and amino acid adequacy

It has long been known that dietary amino acid adequacy is markedly influenced by energy balance but in recent years the importance of this has been generally underestimated. Important practical issues include unintentional variation in energy intake and consequence energy balance that may be responsible for much of the apparent variability in protein requirements. Because variation in energy expenditure and intakes in subjects in energy balance may influence nitrogen balance (NB), a framework for evaluating studies of protein or amino acid adequacy in relation to the level of energy intake needs definition. The common assumption that the type of energy influences protein utilization is probably incorrect with fat as effective as carbohydrate in maintaining NB at energy maintenance. A more difficult conceptual issue relates to the use of protein:energy (P:E) ratios in evaluating adequacy of intakes in relation to requirements. This is necessary given that protein intakes are determined by overall food energy intake that varies markedly throughout the life cycle and with lifestyle. For any diet that might be considered limiting in protein, population groups most likely to be at risk are those with the lowest energy requirements, the sedentary elderly. Thus, increased amino acid density of diets becomes more important for this population, and increased physical activity and higher food intakes at energy balance are likely to reduce the extent of any deficiency. Modeling of the implications of proposed protein and amino acid requirement values for likely risk of deficiency by comparing P:E ratios of intakes and requirements implies high levels of deficiency risk in both developing and developed population groups. This raises the question of whether proposed values for the lysine requirement need to be reevaluated and consideration given to the extent to which adaptive mechanisms might enable the metabolic requirement for protein to be met from current intakes.

Plasma amino acids profiles in children with autism: potential risk of nutritional deficiencies

The plasma amino acid profiles of 36 children with autism spectrum disorders were reviewed to determine the impact of diet on amino acid patterns. Ten of the children were on gluten and casein restricted diets administered by parents, while the other 26 consumed unrestricted diets. No amino acid profile specific to autism was identified. However, children with autism had more essential amino acid deficiencies consistent with poor protein nutrition than an age/gender matched control group. There was a trend for children with autism who were on restricted diets to have an increased prevalence of essential amino acid deficiencies and lower plasma levels of essential acids including the neurotransmitter precursors tyrosine and tryptophan than both controls and children with autism on unrestricted diets. These data indicate that larger, more focused studies of protein nutrition in children with autism are needed in order to determine the extent to which restricted diets might place the developing brains of children with autism at risk from protein malnutrition. The high rate of tryptophan and tyrosine deficiency in this group is also of concern given their role as neurotransmitter precursors.

Insights into the abnormalities of chronic renal disease attributed to malnutrition

Low values of serum proteins and loss of lean body mass are commonly found in patients with chronic renal insufficiency (CRI) and especially in dialysis patients. These abnormalities have been attributed to malnutrition (i.e., an inadequate diet), but available evidence indicates that this is not the principal cause. In contrast, there is persuasive evidence that secondary factors associated with the CRI condition cause abnormalities in protein turnover and ultimately result in low serum protein levels and loss of lean body mass. Recent reports have identified some factors that could interfere with the control of protein turnover in CRI patients, including acidosis, inflammation, and/or resistance to anabolic hormones. Each of these stimulates protein breakdown in muscle and activates a common proteolytic pathway, the ubiquitin-proteasome pathway. Moreover, acidosis or inflammation suppress hepatic albumin synthesis. Understanding the biochemical mechanisms that regulate the ubiquitin-proteasome and other catabolic pathways are required to identify new strategies for preventing protein deficits that are associated with CRI.

Nutritional status of children with solid tumors

BACKGROUND

The purposes of the study were to evaluate prospectively the nutritional status of children with solid tumors who were receiving chemotherapy, to find the most sensitive parameter of protein energy malnutrition, and to determine whether the stage of disease and aggressiveness of chemotherapy have any influence on nutritional status.

METHODS

Fifty patients were followed prospectively from the time of diagnosis throughout chemotherapy. Serum albumin, prealbumin, and weight were measured at the time of diagnosis and before each course of chemotherapy.

RESULTS

At diagnosis, only 2.7% of patients had albumin levels < 3.5 g/dL whereas 36% had prealbumin levels below the normal limit. All patients showed a weight increment of 81 g/day (P = 0.0001), an albumin increment of 0.001 U/day (P = 0.0001), and a prealbumin increment of 0.044 U/day (P = 0.0407). The change in prealbumin values was much more prominent (10-fold higher) in children age < 2 years. Changes in albumin values were not statistically significant by stage of disease but the increment of prealbumin did show statistical significance, which was most prominent in patients with Stage IV disease CCG (children's cancer group classification ) (P = 0.0003). The intensity of chemotherapy had no influence on changes in weight or albumin levels. However, it did influence changes in prealbumin levels, which were most pronounced in the group receiving high dose chemotherapy.

CONCLUSIONS

Based on the results of the current study, the authors believe prealbumin is the most powerful test overall with which to evaluate the nutritional status of children with solid tumors both at the time of diagnosis and throughout chemotherapy.

[Nutrition and chronic liver disease]

The prevalence, causes, and consequences of energy-protein malnutrition (EPM) are reviewed in cirrhosis and its treatment, with special emphasis on those aspects that can be carried out in the ambulatory regime. EPM is a highly prevalent situation in advanced cirrhosis, but it probably already occurs in early stages of the disease. EPM has an important prognosis in cirrhosis. Specifically, the nutritional status could be a better predictor of the evolution after a liver transplant than the conventional prognostic indicators. The increase in the oxidation of fats and proteins is the most important mechanisms in EPM in these patients. The hypermetabolism and the deficit in ingestion are also relevant factors in the EPM in cirrhosis. Conventional diet therapy is the most important tool in the long term nutritional treatment in cirrhosis. The administration of nightly carbohydrate supplements could partially revert the alteration in the oxidation of the energetic substrates in these patients. Also, oral supplements of chemically defined diets could improve the quality of life and the long term survival of these patients. When artificial nutrition is indicated, enteral nutrition is the modality of choice in these patients. Enteral nutrition in cirrhosis is safe, nutritionally effective (as it guarantees an adequate energetic-proteineic ingestion), and in some studies it has been associated with a better short term survival. Adding branched chain amino acids to the diets or enteral supplements meant for cirrhotics would only be essential in patients who show intolerance to the conventional protein. Other changes in the components of the diet formulae meant for cirrhotics are open to further research.

Protein deficiency in a colony of western lowland gorillas (Gorilla g. gorilla)

A syndrome of alopecia and weight loss in a colony of 10 western lowland gorillas (Gorilla gorilla gorilla) in Gabon during a 3-yr period was apparently due to a dietary protein deficiency, with nine individuals affected to some extent. The most severely afflicted was a 4-yr-old female who eventually died as a result of acute gastroenteritis caused by Shigella flexneri. Clinical signs included chronic alopecia, hair discoloration, failure to thrive, and weight loss, and their severity was directly correlated with the degree of hypoalbuminemia (12 g/L in the most extreme case) and normocytic normochromic anemia. Preliminary clinical tests and autopsy results suggested a dietary protein or amino acid deficiency as the cause of the hypoalbuminemia, and further analyses of serum amino acid and protein levels were consistent with a diagnosis of dietary protein deficiency. Supplementation of the colony diet with a protein preparation for humans produced a rapid amelioration of signs and improvement in body and coat condition, a normalization of serum albumin and total protein levels, and disappearance of the anemia in all affected animals except a 12-yr-old male, who responded well to treatment with anabolic steroids. The natural diet of western lowland gorillas is surprisingly high in protein, and the dietary protein requirement of captive gorillas may be increased as a result of the absence of commensal gastrointestinal ciliates.

Replacement of amino acid and protein losses with 1.1% amino acid peritoneal dialysis solution

OBJECTIVE

Losses of nutrients into dialysate may contribute to malnutrition. Peritoneal dialysis (PD) patients are reported to lose 3-4 g/day of amino acids (AAs) and 4-15 g/day of proteins. The extent to which one exchange with a 1.1% AA dialysis solution (Nutrineal, Baxter, Deerfield, IL, U.S.A.) offsets these losses was investigated in a 3-day inpatient study in 20 PD patients.

DESIGN

Simple, open-label, cross-over study on consecutive days in a clinical research unit. On day 1 all patients were given a peritoneal equilibration test (PET). On day 2 they received 1.5% dextrose Dianeal (Baxter) as the first exchange of the day and their usual regimen thereafter. On day 3, the first exchange of the day was the 1.1% AA solution in place of 1.5% Dianeal and the usual PD regimen thereafter. On days 2 and 3 all dialysate effluent was collected and analyzed for AAs and proteins. Patients were maintained on a constant diet.

RESULTS

Losses of AAs and total proteins on day 2 were 3.4 +/- 0.9 g and 5.8 +/- 2.4 g, respectively, totaling 9.2 +/- 2.7 g. The net uptake of AAs on day 3 was 17.6 +/- 2.6 g (80 +/- 12% of the 22 g infused). Mean gains of AAs on day 3 exceeded losses of proteins and AAs on day 2, p < 0.001. Losses of total proteins, but not losses of AAs, and the net absorption of AAs from the dialysis solution were correlated directly with peritoneal membrane transport characteristics, obtained from the PET.

CONCLUSION

Daily losses of AAs and proteins into dialysate are more than offset by gains of AAs absorbed from one exchange with 1.1% AA-based dialysis solution. Net gains of AAs exceeded losses of proteins and AAs in all patients studied. The difference was relatively constant across a wide range of membrane transport types. Net AA gains were approximately two times the total AA and protein losses.

[Nutritional status of patients with HIV infection. Spontaneous evolution during the hospital stay]

BASICS: Evaluate the nutritional status of HIV positive patients who are admitted to hospital for some acute process, and their evaluation, without nutritional support, during the admission.

METHODS

Prospective study in HIV positive patients. Nutritional evaluation (on admission and on release); (1) anthropometric (weight, size, triceps, fold, circumference of the arm, and muscular circumference of the arm, and (2) biochemical (albumin, cholesterol, triglycerides, lymphocytes, pre-albumin, and transferrin). Statistical study: comparison of the paired means and chi squared test.

RESULTS

60 patients. Mean age 32 +/- 4.8 years, 76% men and 23% women. Staging: AIDS 84.8%, non-AIDS 15.2%. Main reason for admission: Infection (80%). Mean stay: 14 days +/- 9.5. Initial nutritional evaluation: normal: 1.7%, protein malnutrition: 5.3%, caloric malnutrition: 38.5%, mixed malnutrition: 54.3%, 85% of the patients refer weight loss. 21 patients (35%) were followed up. There were no significant differences in the anthropometric nor in the biochemical parameters, except in the levels of pre-albumin and transferrin, which improved (p < 0.001). Nutritional evaluation on release: normal: 9.5%, caloric malnutrition: 66.5%, mixed malnutrition: 23.7%. There were no cases of protein malnutrition.

CONCLUSIONS

The vast majority of the HIV+ patients who are admitted, are malnourished, and after curing the acute process, 90.5% of them remain malnourished. The anthropometric measurements, albumin, cholesterol, and triglycerides do not vary during the hospital admission, despite the treatment and the clinical improvement. The increase of proteins with a short half life is due to controlling the infection, which is why these are not good parameters for the nutritional evaluation in these patients.

Caloric rather than protein deficiency predominates in stable chronic haemodialysis patients

BACKGROUND

The monitoring of energy and protein intake is considered fundamental in uraemic patients. However, in the clinical practice only protein ingestion is indirectly evaluated by the protein catabolic rate.

METHODS

In a cross-sectional study we evaluated the relationship between caloric and protein intake of 29 stable chronic haemodialysis patients (18M, 11F, mean age 49 +/- 17 years, 68 +/- 6 months on maintenance haemodialysis), and the validity of protein catabolic rate determination. Normalized protein catabolic rate was obtained according to Sargent's formula, and Watson's equation was used to calculate urea distribution volume. Caloric and protein intake were recorded during a 3-day period, and average daily ingestion of nutrients was calculated using a computerized diet analysis system.

RESULTS

A greater reduction of daily energy intake (26.8 +/- 11.9 Kcal/kg bw) than daily protein intake (1.02 +/- 0.4 g/kg bw) was observed. Fifty-nine percent of patients had low protein intake while 86% of patients had lower caloric intake than recommended. An inverse relationship between age and protein (r = -0.65, P < 0.001) or caloric intake (r = -0.67, P < 0.001) was observed. Negative relationships between daily protein (r = -0.60, P < 0.01) and also caloric intake (r = -0.39, P < 0.05) and the ratio between the urea generation rate and the total dietary nitrogen were found, indicating that in patients with low nutrient intake the nitrogen balance tends to be negative. Normalized protein catabolic rate was directly correlated with protein intake (r = 0.77, P < 0.001). A protein catabolic rate cut-off of 1 g/kg bw correctly identified all patients with normal daily protein intake, and 14 of 17 patients with deficient daily protein intake (< 1 g/kg bw). Thus in only 10% of haemodialysis patients an imbalance between both parameters was observed. Moreover, patients with a daily protein intake lower than 1 g/kg bw were older and showed lower BUN and protein catabolic rate values than their counterparts.

CONCLUSIONS

Nutritional abnormalities are frequently found, even in apparently clinically stable patients on chronic haemodialysis. Caloric rather than protein undernutrition is the major abnormality of their wasting. Inadequate intake of proteins and calories appears more commonly in older patients, and in association with lower BUN and protein catabolic rate values. Although normalized protein catabolic rate shows a direct correlation with a daily protein intake, the identity line shows that when daily protein intake was lower than 1 g/kg bw, it was overestimated by protein catabolic rate. Conversely, when daily protein intake is higher than 1 g/kg bw it is underestimated by the protein catabolic rate. This relationship should to be considered when interpreting the protein catabolic rate in a clinical setting.

Nutritional effect of continuous hemodiafiltration

Continuous arterial-venous and veno-venous hemodiafiltration are reliable methods of renal replacement therapy and are particularly suited to critically ill patients in acute renal failure. Fluid and uremic toxin removal from continuous hemodiafiltration is sufficient to allow unrestricted nutrition support. However, the hemodiafilter cannot discriminate between uremic toxins and nutrients. Therefore, the potential exists for significant nutrient loss during continuous hemodiafiltration. Amino acid loss during continuous hemodiafiltration is approximately 10-15 g/day, although in individual cases > or = 30 g/day can be lost. Neither lipids nor intact proteins are lost to any appreciable degree during continuous hemodiafiltration. Small amounts of glucose are lost if dextrose-free dialysate is used for dialysis. If dextrose-containing dialysate is used, significant amounts of glucose can be absorbed (35-45% of the infused glucose). Fluid replacement with dextrose-containing electrolyte solutions can also lead to significant infusion of glucose. Vitamin and mineral losses during continuous hemodiafiltration are not known; neither are the vitamin requirements for patients receiving continuous hemodiafiltration. Effects of continuous hemodiafiltration on vitamin and mineral loss and status remain an important research question.

[Treatment of severe obesity by calibrated vertical gastroplasty. 55 cases]

OBJECTIVES

Evaluate short-term outcome of calibrated vertical gastroplasty in obese subjects.

METHODS

Calibrated vertical gastroplasty was performed in 55 obese subjects (BMI 43 +/- 1; age range 20-59 year). There were no post-operative complications. All the subjects were followed for 6 months and thirty one for a year.

RESULTS

Weight loss reached 28 kg at 6 months and 36 kg at 1 year with an improvement in functional manifestations, especially for dyspnoea and, in half of the subjects, for signs of depression. New or worsened psychiatric problems were observed in 4 subjects. Post-prandial vomiting persisted for 1 year in 28 patients. Dietary intake was lowered (946 +/- 61 kcal/day) as was protein intake (43 +/- 3 g/24 hr). Impaired glucose tolerance, raised serum insulin, triglyceride and androgen levels were corrected in patients with abnormal levels before surgery. Serum vitamin B1 declined.

CONCLUSION

These favourable results in the weight curve, functional problems and metabolic data should not mask the disadvantages and potential risks involved. Long-term prospective studies are required to determine the precise indications for this technique.

Acid-base regulation in peritoneal dialysis

To prevent increased protein degradation and renal bone disease, optimal correction of acidosis should therefore be a priority in the management of CAPD patients. Initial results suggest that bicarbonate solutions may be more biocompatible than lactate, and one would expect increasing use over the next decade. Manufacturers could help to improve acid-base regulation in CAPD by providing a range of solutions with varying lactate and bicarbonate concentration, so that correction of acidosis could be optimized individually.

Macrobiotic nutrition and child health: results of a population-based, mixed-longitudinal cohort study in The Netherlands

A population-based study on the nutritional status of children consuming macrobiotic diets was carried out in The Netherlands. Participants followed a macrobiotic diet based mainly on whole-grain cereals, pulses, and vegetables. Studies in children aged 0-10 y suggested that growth was retarded mainly between 6 and 18 mo. This was confirmed in a subsequent mixed-longitudinal study (including data on diet, anthropometry, blood chemistry, and pediatric examination) in 4-18 mo-old macrobiotic infants and a matched omnivorous control group. Ubiquitous deficiencies of energy, protein, vitamin B-12, vitamin D, calcium, and riboflavin were detected in macrobiotic infants, leading to retarded growth, fat and muscle wasting, and slower psychomotor development. Breast milk from macrobiotic mothers contained less vitamin B-12, calcium, and magnesium. Supplementation of the macrobiotic diet with fat (minimum 20-25 g/d), fatty fish (minimum 100-150 g/wk), and dairy products (minimum 150-250 g/d) is recommended.

Body protein and lipid deficit in tumour-bearing rats in relation to age

Cancer cachexia is among the most dramatic situations of depletion in body energy reserves. To ascertain whether the pattern of body composition alteration during tumour development is influenced by aging as in uncomplicated starvation, we compared the difference of body composition between Yoshida sarcoma bearing rats and young (200 g, 7 weeks) and adult (400 g, 13 weeks) control rats. After the same duration of tumour bearing, mass and composition of tumours were similar in adult and young rats, indicating that they are independent of host age. Food intake decreased to a remarkably similar value in both young and adults. Body water content was elevated in hosts of both ages. The relative deficit of body lipid vs controls was similar for both, the absolute lipid deficit being therefore larger in adult than in young tumour-bearing rats (14.3 +/- 4.4 g vs 6.8 +/- 0.9 g; P < 0.01). In contrast, there was a relatively larger deficit of body protein in young rats. Paradoxically, these rats still maintained a positive nitrogen balance whereas this balance was negative in adult tumour-bearing rats. In conclusion, as previously shown in uncomplicated undernutrition, the anorexia induced by Yoshida sarcoma development is still associated with some protein accretion in young rats whereas cachexia develops in adults.

[Evaluation of protein compliance in patients with chronic renal insufficiency undergoing hemodialysis treatment]

The majority of hemodialyzed patients manifests a proteic malnutrition. This metabolic status is a main factor in the morbidity and mortality of such subjects. It is therefore necessary to dispose of more adequate diagnostic instrumentation to offset this highly invalidating condition. The ongoing and severe evaluation of the nutritional status by means of up-to-date and sophisticated techniques such as antroproteic parameters may contribute to the maintenance of good conditions while refraining the evolution of various and often lethal complications induced by chronic renal failure.

Stunting and nutrient deficiencies in children on alternative diets

Studies in children fed alternative diets showed that anthropometric parameters and the intake of energy and nutrients by macrobiotic children deviated most from current norms. Therefore weaning practice, growth and haematological status were investigated in 3 age-cohorts of macrobiotic fed infants between 4 and 18 months of age and a control group. A mixed longitudinal design was used for this study. Main findings were a growth retardation which was strongest in the second cohort (8-14 months of age) and related to a diet low in energy density, fat and protein. Haematological data revealed very low vitamin B12 concentrations with consequently low values of haematocrit and red blood cell count and higher values of mean corpuscular volume and mean corpuscular haemaglobin mass in the macrobiotic group. High folate concentrations also seemed to be a consequence of Vitamin B12 deficiency. Iron deficiency was found in 15% of the macrobiotic group vs. no infants in the control group. Nutritional recommendations acceptable within the macrobiotic philosophy are discussed.

[System for assessing the nutritional status of the surgical patient at admission. Nutritional assessment in surgery]

Many studies have shown that the prevalence of malnutrition in hospitals is high. Our aim in this study is to ensure the systematic use of a preoperative nutritional evaluation (PNE) that ensures simplicity and usefulness in hospital nursing assistance. A total of 96 patients were studied, of whom 31 were diagnosed as having neoplasia and 65 non-neoplasia. For the purpose of this evaluation, the Chang method was used, completed with the application of retarded immunity skin tests. Malnutrition was observed in 71% por patients with neoplasia, mainly corresponding to slight Marasmo grade. In non-neoplasic patients malnutrition was 46%, also corresponding to slight Marasmo grade. In patients with neoplasia, anergy was evident in 54.9% of cases, and accounted for 23.1% in non-neoplasic patients. The development of anergy in both types of patients was significantly greater (p less than 0.05) in patients over 65 years of age. The inclusion of a PNE should form part of the nursing protocols, being used systematically in the study and control of surgical patients.

[Protein malnutrition in insulin-dependent or type I diabetes mellitus. Relationship with the degree of metabolic control]

Fifty-eight insulin-dependent diabetic (IDDM) patients with a disease duration of more than three years were evaluated and divided in three groups depending on the mean sugar blood levels in a three month follow-up. In the first group sugar blood level was lower than 7.7 mmol/l, in the second group it was between 7.7 and 11.1 mmol/l, and in the third group it was higher than 11.1 mmol/l. The nutritional status was evaluated. Protein malnutrition was found in 50% of the evaluated subjects, with a significant relation between the degree of metabolic control and the prevalence of protein malnutrition. In group I (sugar blood level less than 7.7 mmol/l) the prevalence of malnutrition was 31%, whereas in groups II and III (greater than 7.7 mmol/l) it was 54% and 61%, respectively. We discuss the importance to evaluate the nutritional status in diabetic patients, as protein malnutrition is a significant cause of general morbidity and mortality, which can be added to those attributable to diabetes itself.