Electrolyte imbalances as poor prognostic markers in COVID-19: a systemic review and meta-analysis.

PURPOSE: Serum electrolyte imbalances are highly prevalent in COVID-19 patients. However, their associations with COVID-19 outcomes are inconsistent, and of unknown prognostic value. We aim to systematically clarify the associations and prognostic accuracy of electrolyte imbalances (sodium, calcium, potassium, magnesium, chloride and phosphate) in predicting poor COVID-19 clinical outcome. METHODS: PubMed, Embase and Cochrane Library were searched. Odds of poor clinical outcome (a composite of mortality, intensive-care unit (ICU) admission, need for respiratory support and acute respiratory distress syndrome) were pooled using mixed-effects models. The associated prognostic sensitivity, positive and negative likelihood ratios (LR + , LR-) and predictive values (PPV, NPV; assuming 25% pre-test probability), and area under the curve (AUC) were computed. RESULTS: We included 28 observational studies from 953 records with low to moderate risk-of-bias. Hyponatremia (OR = 2.08, 95% CI = 1.48-2.94, I2 = 93%, N = 8), hypernatremia (OR = 4.32, 95% CI = 3.17-5.88, I2 = 45%, N = 7) and hypocalcemia (OR = 3.31, 95% CI = 2.24-4.88, I2 = 25%, N = 6) were associated with poor COVID-19 outcome. These associations remained significant on adjustment for covariates such as demographics and comorbidities. Hypernatremia was 97% specific in predicting poor outcome (LR + 4.0, PPV = 55%, AUC = 0.80) despite no differences in CRP and IL-6 levels between hypernatremic and normonatremic patients. Hypocalcemia was 76% sensitive in predicting poor outcome (LR- 0.44, NPV = 87%, AUC = 0.71). Overall quality of evidence ranged from very low to moderate. CONCLUSION: Hyponatremia, hypernatremia and hypocalcemia are associated with poor COVID-19 clinical outcome. Hypernatremia is 97% specific for a poor outcome, and the association is independent of inflammatory marker levels. Further studies should evaluate if correcting these imbalances help improve clinical outcome.

Reduction in unplanned hospitalizations associated with a physician focused intervention to reduce potentially inappropriate medication use among older adults: a population-based cohort study.

BACKGROUND: A multimodal general practitioner-focused intervention in the Local Health Authority (LHA) of Parma, Italy, substantially reduced the prevalence of potentially inappropriate medication (PIM) use among older adults. Our objective was to estimate changes in hospitalization rates associated with the Parma LHA quality improvement initiative that reduced PIM use. METHODS: This population-based longitudinal cohort study was conducted among older residents (> 65 years) using the Parma LHA administrative healthcare database. Crude and adjusted unplanned hospitalization rates were estimated in 3 periods (pre-intervention: 2005-2008, intervention: 2009-2010, post-intervention: 2011-2014). Multivariable negative binomial models estimated trends in quarterly hospitalization rates among individuals at risk during each period using a piecewise linear spline for time, adjusted for time-dependent and time-fixed covariates. RESULTS: The pre-intervention, intervention, and post-intervention periods included 117,061, 107,347, and 121,871 older adults and had crude hospitalization rates of 146.2 (95% CI: 142.2-150.3), 146.8 (95% CI: 143.6-150.0), and 140.8 (95% CI: 136.9-144.7) per 1000 persons per year, respectively. The adjusted pre-intervention hospitalization rate was declining by 0.7% per quarter (IRR = 0.993; 95% CI: 0.991-0.995). The hospitalization rate declined more than twice as fast during the intervention period (1.8% per quarter, IRR = 0.982; 95% CI: 0.979-0.985) and was nearly constant post-intervention (IRR: 0.999; 95% CI: 0.997-1.001). Contrasting model predictions for the intervention period (Q1 2009 to Q4 2010), the intervention was associated with 1481 avoided hospitalizations. CONCLUSION: In a large population of older adults, a multimodal general practitioner-focused intervention to decrease PIM use was associated with a decline in the unplanned hospitalization rate. Such interventions to reduce high risk medication use among older adults warrant consideration by health systems seeking to improve health outcomes and reduce high-cost acute care utilization.

Comparison of two different optical coherence tomography angiography devices in detecting healthy versus glaucomatous eyes - an observational cross-sectional study.

BACKGROUND: To understand the differences between two different optical coherence tomography angiography (OCTA) devices in detecting glaucomatous from healthy eyes by comparing their vascular parameters, diagnostic accuracy and test-retest reliability. METHODS: A cross-sectional observational study was performed on healthy and glaucoma subjects, on whom two sets of OCTA images of optic disc and macula were acquired using both AngioVue (Optovue, USA) and Swept Source (Topcon, Japan) OCTA devices during one visit. A novel in-house software was used to calculate the vessel densities. Diagnostic accuracy of the machines in differentiating healthy versus glaucomatous eyes was determined using area under the receiver operating characteristic curve (AUROC) and test-retest repeatability of the machines was also evaluated. RESULTS: A total of 80 healthy and 38 glaucomatous eyes were evaluated. Glaucomatous eyes had reduced mean vessel density compared to healthy controls in all segmented layers of the optic disc and macula using AngioVue (p ≤ 0.001). However, glaucomatous eyes had higher mean vessel density on optic disc scans using Swept Source, with lack of statistically significant difference between healthy and glaucomatous eyes. The AUROC showed better diagnostic accuracy of AngioVue (0.761-1.000) compared to Swept Source (0.113-0.644). The test-retest reliability indices were generally better using AngioVue than Swept Source. CONCLUSIONS: AngioVue showed better diagnostic capability and test-retest reliability compared to Swept Source. Further studies need to be undertaken to evaluate if there is any significant difference between the various machines in diagnosing and monitoring glaucoma.

Strategies to Improve the Potential Functionality of Fruit-Based Fermented Beverages.

It is only recently that fermentation has been facing a dynamic revival in the food industry. Fermented fruit-based beverages are among the most ancient products consumed worldwide, while in recent years special research attention has been granted to assess their functionality. This review highlights the functional potential of alcoholic and non-alcoholic fermented fruit beverages in terms of chemical and nutritional profiles that impact on human health, considering the natural occurrence and enrichment of fermented fruit-based beverages in phenolic compounds, vitamins and minerals, and pro/prebiotics. The health benefits of fruit-based beverages that resulted from lactic, acetic, alcoholic, or symbiotic fermentation and specific daily recommended doses of each claimed bioactive compound were also highlighted. The latest trends on pre-fermentative methods used to optimize the extraction of bioactive compounds (maceration, decoction, and extraction assisted by supercritical fluids, microwave, ultrasound, pulsed electric fields, high pressure homogenization, or enzymes) are critically assessed. As such, optimized fermentation processes and post-fermentative operations, reviewed in an industrial scale-up, can prolong the shelf life and the quality of fermented fruit beverages.

The Ski proto-oncogene regulates body composition and suppresses lipogenesis.

OBJECTIVE: The Ski gene regulates skeletal muscle differentiation in vitro and and in vivo. In the c-Ski overexpression mouse model there occurs marked skeletal muscle hypertrophy with decreased adipose tissue mass. In this study, we have investigated the underlying molecular mechanisms responsible for the increased skeletal muscle and decreased adipose tissue mass in the c-Ski mouse. APPROACH: Growth and body composition analysis (tissue weights and dual energy X-ray absorptiometry) coupled with skeletal muscle and white adipose gene expression and metabolic phenotyping in c-Ski mice and wild-type (WT) littermate controls was performed. RESULTS: The growth and body composition studies confirmed the early onset of accelerated body growth, with increased lean mass and decreased fat mass in the c-Ski mice. Gene expression analysis in skeletal muscle from c-Ski mice compared with WT mice showed significant differences in myogenic and lipogenic gene expressions that are consistent with the body composition phenotype. Skeletal muscle of c-Ski mice had significantly repressed Smad1, 4, 7 and myostatin gene expression and elevated myogenin, myocyte enhancer factor 2, insulin-like growth factor-1 receptor and insulin-like growth factor-2 expression. Strikingly, expression of the mRNAs encoding the master lipogenic regulators, sterol-regulatory enhancer binding protein 1c (SREBP1c), and the nuclear receptor liver X-receptor-alpha, and their downstream target genes, SCD-1 and FAS, were suppressed in skeletal muscle of c-Ski mice, as were the expressions of other nuclear receptors involved in adipogenesis and metabolism, such as peroxisome proliferator-activated receptor-gamma, glucocorticoid receptor and retinoic acid receptor-related orphan receptor-alpha. Transfection analysis demonstrated Ski repressed the SREBP1c promoter. Moreover, palmitate oxidation and oxidative enzyme activity was increased in skeletal muscle of c-Ski mice. These results suggest that the Ski phenotype involves attenuated lipogenesis, decreased myostatin signalling, coupled to increased myogenesis and fatty acid oxidation. CONCLUSION: Ski regulates several genetic programs and signalling pathways that regulate skeletal muscle and adipose mass to influence body composition development, suggesting that Ski may have a role in risk for obesity and metabolic disease.

High thermal stress responses of Echinolittorina snails at their range edge predict population vulnerability to future warming.

Populations at the edge of their species' distribution ranges are typically living at the physiological extreme of the environmental conditions they can tolerate. As a species' response to global change is likely to be largely determined by its physiological performance, subsequent changes in environmental conditions can profoundly influence populations at range edges, resulting in range extensions or retractions. To understand the differential physiological performance among populations at their distribution range edge and center, we measured levels of mRNA for heat shock protein 70 (hsp70) as an indicator of temperature sensitivity in two high-shore littorinid snails, Echinolittorina malaccana and E. radiata, between 1°N to 36°N along the NW Pacific coast. These Echinolittorina snails are extremely heat-tolerant and frequently experience environmental temperatures in excess of 55 °C when emersed. It was assumed that animals exhibiting high temperature sensitivity will synthesize higher levels of mRNA, which will thus lead to higher energetic costs for thermal defense. Populations showed significant geographic variation in temperature sensitivity along their range. Snails at the northern range edge of E. malaccana and southern range edge of E. radiata exhibited higher levels of hsp70 expression than individuals collected from populations at the center of their respective ranges. The high levels of hsp70 mRNA in populations at the edge of a species' distribution range may serve as an adaptive response to locally stressful thermal environments, suggesting populations at the edge of their distribution range are potentially more sensitive to future global warming.

The effect on protein and amino acid metabolism of an intravenous nutrition regimen providing seventy percent of nonprotein calories as lipid.

BACKGROUND: The purpose of this study was to determine which peripheral intravenous nutrition (IVN) regimen, one containing 70% nonprotein calories as lipid IVN or one containing all nonprotein calories as glucose IVN, was most effective at reversing some effects of surgery on protein metabolism. METHODS: Twenty patients who required IVN after operation were randomized into two well-matched groups that received 36 kcal.kg-1.day-1 glucose IVN or 37 kcal.kg-1.day-1 lipid IVN. RESULTS: Both IVN regimens resulted in similar changes of nitrogen balance, plasma liver enzymes, blood urea, plasma albumin, and plasma prealbumin. Mean plasma transferrin rose significantly after glucose IVN (p less than 0.01), a change greater than that after lipid IVN (p less than 0.05). Lipid IVN resulted in continued net efflux of alanine from peripheral tissues at rates similar to pretreatment values; glucose IVN significantly reduced net alanine efflux (p less than 0.05). Most of the extra alanine produced by peripheral tissues during lipid IVN appeared to derive from an increased uptake of intramuscular glutamate and from an increased uptake of branched chain amino acids. CONCLUSIONS: The results of this study indicate that 38 kcal.kg-1.day-1 lipid IVN was equivalent to glucose IVN, except for the continuing gluconeogenesis of alanine and the delayed recovery of plasma transferrin concentration after surgery. A greater infusion rate of such a regimen may be necessary to provide sufficient glucose to suppress gluconeogenesis.

Organ clearance of tyrosyl-arginine and its effect on amino acid metabolism in young sheep.

In a long-term multiple-catheter sheep model (n = 5), organ clearance of the dipeptide tyrosyl-arginine (TyrArg) and its effects on interorgan amino acid metabolism were investigated. Clearance by hindlimb and splanchnic tissues was measured during infusion into the external iliac artery and superior mesenteric artery, respectively. The hindlimb, intestine, and total splanchnic region removed 32% +/- 9.2% (mean +/- SE), 23% +/- 15%, and 33% +/- 24%, respectively, of the amount of TyrArg infused. There was a large release of tyrosine and arginine when TyrArg was infused into either the hindlimb or intestine, which was quantitatively similar to the TyrArg taken up by these organs. However, across the total splanchnic region, the baseline influx of tyrosine and arginine was not altered by infusion of TyrArg. During either clearance study, only trace amounts of TyrArg or its constituent amino acids were excreted in urine. Infusion of TyrArg produced the following effects on interorgan amino acid metabolism: (1) a reduction in the initial efflux of phenylalanine, leucine, isoleucine, and valine from the hindlimb; (2) a reduction in net efflux of citrulline by the intestine and total splanchnic tissues; and (3) a reduction in efflux of arginine and uptake of citrulline from the kidney. In conclusion, we have shown that TyrArg is cleared from the bloodstream by hindlimb (predominantly muscle) and splanchnic tissues. These results indicate that TyrArg taken up by the hindlimb and intestine was hydrolyzed to its constituent amino acids, which were released quantitatively into the circulation. Of the tissues studied, only the liver appeared to use the amino acids liberated from hydrolysis of TyrArg.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of dipeptide structure on dipeptide and amino acid clearance in rats.

The kinetics of disappearance from the blood of GlyTyr, TyrArg, AlaTyr, TyrAla, GlnGly, GlyGln, GlnAla, and AlaGln and their constituent amino acids was assessed in anesthetized (pentabarbitone) Sprague-Dawley rats (n = 5 for each peptide). Catheters were inserted into both internal jugular veins. A bolus injection of dipeptide was administered into one catheter, and rapid blood samples were taken from the other catheter for measurement of dipeptide and amino acid concentrations. Kinetic parameters for the disappearance of dipeptides and of the amino acids released from the dipeptides from the blood were calculated using standard equations. All dipeptides were cleared rapidly from the blood (clearances ranged from 42.9 +/- 3.28 mL/min/kg body weight for GlyGln to 278 +/- 70.7 for GlnAla, mean +/- SD). Glutaminyl dipeptides with alanine or glycine in the C-terminal position or dipeptides with alanine in the N-terminal position had the greatest clearance values and the shortest half-lives (t1/2). There were significant differences (P < .001) in the volume of distribution of the dipeptides. Many dipeptides had volumes of distribution greater than the blood volume of the animals. The amino acids released from the dipeptides had a longer t1/2 (P < .001) than their parent dipeptides. The t1/2 and the weight-corrected area under the blood concentration-versus-time curve (AUC) of the same amino acid released from different dipeptides differed (P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of hyperglycemia on pyruvate dehydrogenase activity and energy metabolites during ischemia and reperfusion in gerbil brain.

The effects of hyperglycemia on brain pyruvate dehydrogenase (PDH) and metabolites (ATP, PCr, and lactate) were investigated at 20 min ischemia, 0, 20, and 60 min, and 4 h reperfusion. During reperfusion, PDH activities were suppressed corresponding to the poor recovery of ATP and PCr concentrations and the increase in lactate concentration in the hyperglycemic group, suggesting that preischemic hyperglycemia may impair metabolism by suppressing PDH activity.

The effect of the rate and route of nutrient delivery on total body and organ composition in rats.

To assess the effects of administering increasing rates of total parenteral nutrition (TPN) on total-body and organ composition, infusion catheters were implanted aseptically into the right jugular vein of Sprague-Dawley rats. Animals received 14 d of either a high (H), medium (M), or low (L) rate of TPN infusion (1.22, 1.49, 1.74 MJ.kg-1BW.d-1 and 1.74, 1.48, 1.22 gN.kg-1BW.d-1, respectively: 1:1 lipid:glucose energy), or the TPN solution orally (O TPN group). Weight-matched (w) chow-fed (c) animals were sacrificed at the same final weight as the L TPN and O TPN groups (190 g, LWC group), or the M and H TPN groups (250 g, HWC group). There were 5 animals in each group. The rates of body weight increase of the M TPN, H TPN, and HWC groups were similar (p > 0.05) and greater than the L TPN and O TPN groups (p < 0.001). The L TPN and O TPN groups who received similar amounts of nutrients had similar rates of weight gain. Total body lipid expressed as a percentage of body weight was significantly greater (P < 0.01) in the L, M, and H TPN groups compared to the orally fed groups. The proportion of water and protein in the fat-free wet weight were similar for all groups (p > 0.05). The lipid content of the liver as a percentage of its weight was greater (P < 0.05) in the orally fed groups. There was no significant difference in the percentage of water or protein of individual organs or the total viscera between any group. These finding indicate that: (a) TPN administration can maintain similar rates of protein and water deposition compared to normal growth-maintaining oral diets; (b) there is an effect of route of TPN administration on lipid deposition in adipose tissues; and (c) infusion of a glucose/lipid TPN regimen at rates in excess of requirements for growth in rats promotes lipid deposition in adipose tissues rather than visceral tissues.

Addition of tyrosyl-arginine to parenteral nutrition is anabolic in unstressed rats.

To determine whether the addition of tyrosine and arginine (Arg), as tyrosyl-arginine (TyrArg), to parenteral nutrition (PN) can promote anabolism, rats were assigned to: 1) PN (1.20 MJ. kg body weight [BW](-1) x d(-1) and 1.22 gN x kgBW(-1) x d(-1); PN control group, n = 5), 2) PN plus TyrArg (2.6 mmol. kgBW(-1) x d(-1); TyrArg group, n = 6), or 3) PN plus Arg (2.6 mmol. kgBW(-1). d(-1); Arg group, n = 5). Results from these three groups were compared with an unoperated chow-fed reference group (chow control group, n = 5). The BW gain during PN and the proportion of lipid in the total body after 14 d of PN was greater for the TyrArg group than for the PN group (P<0.01). Although the differences in weight gain, body water, lipid, and protein between the TyrArg and Arg groups were not significant, the mean weight gain throughout PN was greater in the TyrArg group than in the Arg group. The proportion of protein in the small intestine, colon, and gastrocnemius muscle was greater in the TyrArg and Arg groups than in the PN group (P<0.01). A distinct requirement for tyrosine has not been demonstrated in this model, and additional studies in stressed animals are required. In contrast, arginine had tissue-specific anabolic activity.

Metabolic response to a high-lipid, high-nitrogen peripheral intravenous nutrition solution after major upper-gastrointestinal surgery.

We compared the metabolic response to peripheral intravenous nutrition (peripheral IVN) with the response to central IVN when given after major gastrointestinal surgery. Eighteen consecutive patients who had undergone upper-gastrointestinal surgery were randomly assigned to receive either peripheral IVN (75% nonprotein calories supplied as lipid, n = 9) or central IVN (n = 9). Each group received 0.50 +/- 0.03 g N.kg-1 fat-free mass.day-1 (mean +/- SD with 100:1 kcal:g N (0.42 MJ:1 g N). Metabolic studies were undertaken before IVN (2nd postoperative day) and after 10 days of IVN. Negative nitrogen balance was reversed with both treatments (p < 0.001). The significant net efflux of individual amino acids from peripheral tissue before IVN was reduced toward balance, and there were no significant differences between the groups. The postoperative response of the plasma proteins (fibronectin, prealbumin, and transferrin) was similar in both groups. Peripheral IVN decreased postoperative peripheral net uptake of glucose to a net balance. Central IVN resulted in decreased free fatty acid, glycerol, and beta-hydroxybutyrate concentration with increases in plasma insulin concentration and the net uptake of glucose and pyruvate in peripheral tissue. The effect of intravenous nutrition on the metabolic response to major surgery was similar when nonprotein calories were supplied wholly as glucose requiring a central delivery system or when 75% of nonprotein calories were given as lipid when a peripheral delivery system was used. This study supports the development of peripheral IVN feeding systems.

Simultaneous human forearm and calf metabolic exchange.

Simultaneous forearm and leg metabolic exchange studies were performed to compare metabolic exchange and change in metabolic activity over time across the forearm and calf skeletal muscle beds in response to nutritional treatment. Seven postoperative upper-gastrointestinal resection patients received intravenous nutrition (IVN) for 10 days. Immediately before IVN was begun, simultaneous ipsilateral forearm and calf blood flow with arterial and venous sampling for plasma glucose and free fatty acids (FFAs), and whole-blood glycerol, lactate, pyruvate, and nitrogen were measured. After 10 days of IVN, these parameters were repeated in carefully standardized steady-state conditions. Although there were no differences between the arm and the leg with mean flux measurements, correlation of arm and leg flux values were only significant for FFA (p < 0.01) and blood nitrogen (p < 0.05). Forearm and leg metabolic exchange results were not in sufficient agreement to permit reliable use of these results interchangeably for individuals. Errors in blood flow measurement appear to be a major determinant of the poor relationship between forearm and leg flux measurements (limits of agreement 3.32-4.72 ml.dl-1 tissue.min-1). In conclusion, both forearm and leg metabolic exchange studies can be used to show the metabolic effects of treatment when groups of subjects are studied, but variability of the methods used result in poor agreement for the measurements of an individual.

An articulation model to increase student enrollment in a dental hygiene program.

Models to increase student enrollment have been presented accessing both community college and university systems. While these approaches identify certain potential student consumers, the secondary and postsecondary student has not been considered as a viable recruit for baccalaureate degree programs. The purposes of this paper are to (1) present a model to access secondary students with entry-level skills using a partnership agreement; (2) establish a mechanism where dental aides are provided with opportunity for advanced placement; (3) provide ladder educational steps for advancing motivated and qualified health professionals; and (4) provide criteria for statewide development and sources of potential external funding for statewide implementation. This articulation model is an example of one method to increase student enrollment in both associate and baccalaureate degree programs utilizing an established statewide secondary vocational program.

Resting energy expenditure of morbidly obese patients using indirect calorimetry: a systematic review.

The increasing proportion of acutely ill hospital patient admissions presenting with a morbidly obese body mass index (BMI ≥ 40 kg m(-2) ) as a comorbidity is an emerging clinical concern. Suboptimal food intake and malnutrition is prevalent in the acute care hospital setting. The energy requirements necessary to prevent malnutrition in acutely ill patients with morbid obesity remains unclear. The aim of this systematic review was to identify studies in the literature that have used indirect calorimetry to measure the resting energy expenditure of patients with morbid obesity to establish their minimum energy requirements and the implications for optimal feeding practices in acutely ill hospitalized patients. A total of 20 studies from PubMed, Cochrane Library and Embase met the inclusion criteria and were reviewed. All articles were graded using the Australian National Health and Medical Research Council levels of evidence and given a quality rating using the American Dietetic Association recommendations. Studies were categorized according to the mean BMI of its subjects. The most commonly measured resting energy expenditures for morbidly obese patients are between 2,000 and 3,000 kcal d(-1) (8,400-12,600 kJ d(-1) ). Activity and injury factors of acutely ill morbidly obese patients could result in significantly greater energy requirements for this patient group and are unlikely to be met by standard hospital menus. Establishing the minimum energy requirements for this population group will help inform adequate and accurate energy provision in the acute setting. Outcomes of underfeeding and overfeeding in morbidly obese patients warrant further research.

An investigation into the temperature dependence of the rheological synergy between xanthan gum and locust bean gum mixtures.

The interaction between xanthan gum (XG) and locust bean gum (LBG) in water has been investigated using texture analysis, thermorheological analysis and high sensitivity differential scanning calorimetry. For the batches of XG and LBG used in the present study and at a total polymer concentration of 1% w/v, texture analysis indicated that the greatest synergy occurred at approximately 10% w/w XG, while the technique also allowed measurement of the increase in strength resulting from heating the mixes to 70 and 80 degrees C and cooling to room temperature. Thermorheological studies showed a maximum in viscosity for the xanthan gum gels at approximately 45 degrees C; this maximum became less pronounced as the concentration of XG decreased. High sensitivity differential scanning calorimetry indicated that XG undergoes two transitions at approximately 30 and 80 degrees C on heating, but on cycling a single transition is seen at approximately 74 degrees C. It was also noted that the transitions were diminished or were absent in the presence of LBG.

Metabolic evaluation of a 75% lipid/25% glucose high nitrogen solution for intravenous nutrition.

OBJECTIVE: To compare the metabolic response to a 75% lipid/25% glucose regimen of intravenous feeding with that of a regimen of isocaloric isonitrogenous glucose alone. DESIGN: Randomised crossover study. SETTING: University department of surgery. SUBJECTS: 14 Patients (of 18 consecutive) who did not develop infections after major upper gastrointestinal operations. INTERVENTIONS: Patients received five days of each of two regimens, both of which provided 0.38 g nitrogen and 0.155 MJ (37 kcal)/kg/day. MAIN OUTCOME MEASURES: Nitrogen balance, prealbumin and transferrin concentrations, and basal efflux of amino acids from the lower limb before and after a five day course of each regimen. RESULTS: Mean (SD) nitrogen balance increased from -11.4 (2.6) g/day to 1.7 (4.1) and 1.6 (5.5) g/day after lipid/glucose and glucose alone, respectively (p < 0.0001). Basal prealbumin and transferrin concentrations increased after both regimens, but significantly so only after lipid/glucose (p < 0.01 and < 0.02, respectively). Mean (SD) net basal efflux of total amino acids from the lower limb was significantly reduced after both regimens, (p < 0.0001 in each case). Net basal alanine efflux was significantly reduced only by glucose alone, and basal glutamine efflux only by lipid/glucose (p < 0.05 in each case). Plasma free fatty acids were increased only by glucose alone (p < 0.001), and glucose alone augmented tissue uptake of glucose significantly more than lipid/glucose (p < 0.01 and < 0.05, respectively). CONCLUSIONS: The solution high in lipids and nitrogen was well tolerated. There was no difference in improvements in nitrogen balance or amino acid flux across the lower limb, but lipid/glucose was associated with higher increases in visceral protein concentrations.

Validity of urinary urea nitrogen as a measure of total urinary nitrogen in adult patients requiring parenteral nutrition.

The validity of the urinary urea nitrogen (UUN) estimate of total urinary nitrogen (TUN) was tested in patients who required iv nutrition. UUN and TUN were determined in 120 urine collections from ten preoperative, 13 postoperative, and 11 stressed patients. The relationship between TUN and UUN was examined by linear regression, and analysis of covariance was used on log-transformed data to assess differences between the patient groups. Although there was a close relationship between UUN and TUN for the preoperative patients (r2 = .94, total range of differences = 3.85 g N), this was not as accurate in postoperative and stressed patients (r2 = .69 and .76, respectively, total range of differences = 16.8 and 10.7 g N, respectively). There was no significant difference between the slopes of the regression lines for the relationship between UUN and TUN for three groups (f = 1.1, df = 2114, p less than .3), but the intercepts of the regression lines differed between the preoperative and stressed patient groups (t = 3.47, v = 114, p less than .001). The relationship between TUN and UUN for the whole group was improved by the inclusion of the independent variables of both the patient's clinical state and the urinary creatinine excretion. Arm muscle circumference, which is an estimate of muscle mass, may replace creatinine excretion with little loss in prediction accuracy.

Parenteral amino acid intake alters the anabolic actions of insulin-like growth factor I in rats.

The anabolic properties of insulin-like growth factor (IGF) I are attenuated by oral diets that are low in protein. However, it is not known whether parenteral nutrition (PN) providing a low amino acid (AA) input will influence IGF-I action. With the use of a rat model, this study examined the interaction between AA input (1.27 and 0.62 g N. kg body wt(-1). 24 h(-1), AA and 1/2AA groups, respectively) and recombinant human IGF-I (rhIGF-I, 2.5 mg. kg body wt(-1). 24 h(-1)) infusion on the composition of the carcass and organs and on plasma insulin, IGF-I, IGF-binding protein 1 (IGFBP-1), and acid-labile subunit (ALS) concentrations. Carcass protein deposition only occurred in the AA groups (P < 0.003) and was not influenced by administration of rhIGF-I. However, visceral protein loss persisted in the AA group but was prevented by rhIGF-I infusion. The changes in water content of the carcass and the organs were generally in the expected proportion of normal lean tissue. The accumulation of lipid that follows the infusion of the AA-deficient PN was prevented by rhIGF-I infusion, which may indicate an improved energy utilization. Neither serum insulin nor ALS concentrations were influenced by the level of AA infusion but were reduced by rhIGF-I administration. However, plasma IGF-I levels were elevated by higher AA infusion and by IGF-I administration. Also, IGFBP-1 concentrations were reduced by the higher AA infusion and increased with rhIGF-I administration. Interestingly, there was a significant interaction effect between both of these influences. It is concluded that free IGF-I concentration, which may be regulated by IGFBP-1 through a direct effect of AAs on the liver, may have an important role in regulating anabolism in visceral and possibly skeletal tissue during PN.