Impact of frailty, malnutrition and socioeconomic status on perioperative outcomes

BACKGROUND

Frailty, malnutrition and low socioeconomic status may mutually perpetuate each other in a self-reinforcing and interdependent manner. The intertwined nature of these factors may be overlooked when investigating impacts on perioperative outcomes. This study aimed to investigate the impact of frailty, malnutrition and socioeconomic status on perioperative outcomes.

METHODS

A multicentre cohort study involving six Australian tertiary hospitals was undertaken. All consecutive surgical patients who underwent an operation were included. Frailty was defined by the Hospital Frailty Risk Score, malnutrition by the Malnutrition Universal Screening Tool (MUST) and low socioeconomic status by the Index of Relative Socioeconomic Disadvantage. Linear mixed-effects and binary logistic generalised estimated equation models were performed for the outcomes: inpatient mortality, length of stay, 30-day readmission and re-operation.

RESULTS

A total of 21 976 patients were included. After controlling for confounders, malnutrition and socioeconomic status, patients at high risk of frailty have a mean hospital length of stay 3.46 times longer (mean ratio = 3.46; 95% confidence interval (CI): 3.20, 3.73; P value < .001), odds of 30-day readmission 2.4 times higher (odds ratio = 2.40; 95% CI: 2.19, 2.63; P value < .001) and odds of in-hospital mortality 12.89 times greater than patients with low risk of frailty (odds ratio = 12.89; 95% CI: 4.51, 36.69; P value < .001). Elevated MUST scores were also significantly associated with worse outcomes, but to a lesser extent. Socioeconomic status had no association with outcomes.

CONCLUSION

Perioperative risk evaluation should consider both frailty and malnutrition as separate, significant risk factors. Despite strong causal links with frailty and malnutrition, socioeconomic disadvantage is not associated with worse postoperative outcomes. Additional studies regarding the prospective identification of these patients with implementation of strategies to mitigate frailty and malnutrition and assessment of perioperative risk are required.

Exogenous glucagon-like peptide-1 attenuates glucose absorption and reduces blood glucose concentration after small intestinal glucose delivery in critical illness

OBJECTIVE

To evaluate the effect of exogenous glucagonlike peptide-1 (GLP-1) on small intestinal glucose absorption and blood glucose concentrations during critical illness.

DESIGN, SETTING AND PARTICIPANTS

A prospective, blinded, placebo-controlled, cross-over, randomised trial in a mixed medical-surgical adult intensive care unit, with 12 mechanically ventilated critically ill patients, who were suitable for receiving small intestinal nutrient.

INTERVENTIONS

On consecutive days, in a randomised order, participants received intravenous GLP-1 (1.2 pmol/ kg/min) or placebo (0.9% saline) as a continuous infusion over 270 minutes. After 6 hours of fasting, intravenous infusions of GLP-1 or placebo began at T = -30 min (in which T = time), with the infusion maintained at a constant rate until study completion at T = 240 min. At T = 0 min, a 100 mL bolus of mixed liquid nutrient meal (1 kcal/mL) containing 3 g of 3-O-methyl-D-gluco-pyranose (3-OMG), a marker of glucose absorption, was administered directly into the small intestine, via a post-pyloric catheter, over 6 minutes.

MAIN OUTCOME MEASURES

Blood samples were taken at regular intervals for the measurement of plasma glucose and 3-OMG concentrations.

RESULTS

Intravenous GLP-1 attenuated initial small intestinal glucose absorption (mean area under the curve [AUC]0-30 for 3-OMG: GLP-1 group, 4.4 mmol/L/min [SEM, 0.9 mmol/L/min] v placebo group, 6.5 mmol/L/min [SEM, 1.0 mmol/L/min]; P = 0.01), overall small intestinal glucose absorption (mean AUC0-240 for 3-OMG: GLP-1, 68.2 mmol/L/ min [SEM, 4.7 mmol/L/min] v placebo, 77.7 mmol/L/min [SEM, 4.4 mmol/lLmin]; P = 0.02), small intestinal glucose absorption and overall blood glucose concentration (mean AUC0-240 for blood glucose: GLP-1, 2062 mmol/L/min [SEM, 111 mmol/L/min] v placebo 2328 mmol/L/min [SEM, 145 mmol/L/min]; P = 0.005).

CONCLUSIONS

Short-term administration of exogenous GLP-1 reduces small intestinal glucose absorption for up to 4 hours during critical illness. This is likely to be an additional mechanism for the glucose-lowering effect of this agent.

Radiation enteritis

Acute radiation enteritis is almost inevitable in the curative treatment of malignant tumors of the abdomen and pelvic area. It is frequently a self-limiting disorder of intestinal function associated with reversible mucosal changes of the intestine. The prevalence of chronic radiation enteritis has been underestimated in most surgical series and the majority of patients with symptoms probably do not seek medical advice until a serious complication occurs. Although associated with specific histologic features, the mechanism of chronic radiation injury is poorly understood. The prevalence, pathogenesis, diagnosis and approaches to the treatment and prevention of acute and chronic radiation enteritis are discussed herein. Recent investigative techniques should lead to a better understanding of the physiopathologic characteristics of radiation enteritis and, thereby, provide a more rational basis for treatment which, at the present time, is unsatisfactory. Attempts to reduce the prevalence of radiation enteritis should be directed toward careful patient selection for radiation treatment of the pelvis and to minimize injury to the small intestine, by reducing the volume of small intestine in the radiation area and providing more individualized dosimetry.

Diabetes mellitus is an independent risk factor for a greater frequency of early satiation and diarrhea at one and three years: Two prospective longitudinal population-based studies

BACKGROUND

Psychological and lifestyle factors have been associated with gastrointestinal (GI) symptoms in individuals with diabetes mellitus, but it remains unclear whether they explain the relationship over time. We aimed to determine in two independent population-based studies whether diabetes is an independent risk factor for GI symptoms at a 1- and 3-year follow-up, adjusting for these factors.

METHODS

In study 1, 1900 individuals completed a baseline and 1-year follow-up survey, while in study 2, 1322 individuals completed a baseline and 3-year follow-up survey. Both studies asked about self-reported diagnoses of diabetes and GI symptoms over the previous 3 months. Psychological, lifestyle factors (body mass index [BMI], smoking) and age and sex were assessed.

KEY RESULTS

The baseline prevalence of diabetes was 7.8% in Survey 1 and 8.9% in Survey 2. In a multivariate model that included age, sex, BMI, anxiety, depression and smoking status at follow-up, reporting diabetes at baseline was an independent predictor of at least weekly early satiation (OR 1.58, 95% CI 1.05, 2.39, p = 0.03; OR = 1.67, 95% CI 1.14, 2.45, p = 0.009), fecal urgency (OR 1.44,95% CI 1.06, 1.95, p = 0.02; OR = 2.17, 95% CI 1.47, 3.22, p = 0.0001), > 3 bowel motions a day (OR 1.50, 95% CI 1.08, 2.07, p = 0.02; OR = 1.67, 95% CI 1.11, 2.51, p = 0.01), and loose stools (OR 1.40, 95% CI 1.04, 1.90, p = 0.03; OR = 1.68, 95% CI 1.13, 2.51, p = 0.01) at the 1- and 3-year follow-ups, respectively.

CONCLUSIONS & INFERENCES

Diabetes is an independent risk factor for a greater frequency of early satiation and diarrhea, adjusting for lifestyle and psychological factors.

Acute decrease in the plasma tryptophan-to-large-neutral-amino-acids ratio attenuates the effects of L-tryptophan on gut hormones and energy intake in healthy males: a randomized, cross-over, exploratory trial

BACKGROUND

L-tryptophan ("Trp") and L-leucine ("Leu"), when administered intraduodenally, increase plasma cholecystokinin (CCK) and glucagon-like peptide 1 (GLP-1) and stimulate pyloric pressures, which all slow gastric emptying and suppress subsequent energy intake. The circulating Trp-to-large-neutral-amino-acids ("Trp/LNAAs") ratio is also inversely related to energy intake.

OBJECTIVES

This exploratory study characterized the impact of standardized changes in the plasma Trp/LNAAs ratio, achieved by combining a fixed-load intraduodenal infusion of Trp with increasing loads of Leu, on the appetite-inhibitory effects of enteral Trp.

METHODS

Twelve males of normal weight [mean ± standard deviation; age: 23 ± 2 y; body mass index (in kg/m2: 23±1)], received on 4 separate occasions, 90-min iso-osmotic intraduodenal infusions of 1) isotonic 0.9% saline ("control"), 2) Trp (0.15 kcal/min; "Trp"), 3) Trp + Leu (0.22 kcal/min; "Trp+Leu-0.22"), or 4) Trp + Leu (0.45 kcal/min; "Trp+Leu-0.45"), in a randomized, double-blind, cross-over fashion. Immediately postinfusion ad-libitum energy intake was quantified. Plasma CCK, GLP-1, amino acid concentrations, and antropyloroduodenal pressures were measured throughout.

RESULTS

Although there was a transient stimulation of CCK and GLP-1 by Trp + Leu - 0.45 (at t = 15 min), only Trp led to a sustained increase in plasma CCK (P = 0.04) and GLP-1 (P = 0.009) from t = 60-90 min, and stimulated pyloric pressures (P = 0.01), compared with control. Only Trp reduced energy intake [kcal (mean ± standard error of the mean); control: 1085 ± 49, Trp: 881 ± 75, Trp + Leu - 0.22: 963 ± 57, Trp + Leu - 0.45: 932 ± 60] compared with control (P = 0.008). The Trp/LNAAs ratio was dose-dependently decreased by Trp + Leu - 0.22 and Trp + Leu - 0.45, compared with Trp (all P = 0.001), and energy intake correlated inversely with the Trp/LNAAs ratio (R = -0.38; P = 0.02).

CONCLUSIONS

Acute reduction in the Trp/LNAAs ratio appears to be associated with a diminished capacity of Trp to stimulate CCK and GLP-1 and suppress energy intake. Although these observations should be interpreted with caution given the exploratory nature of the study, they attest to the complexity of the relationships between pre and postabsorptive mechanisms underlying Trp's appetite-inhibitory effect. This trial was registered at the Australian New Zealand clinical trial registry as ACTRN12620001275954.

Relationship between forearm and vertebral mineral density in postmenopausal women with primary hyperparathyroidism

Vertebral and forearm mineral density of 28 postmenopausal women with mild primary hyperparathyroidism was measured and compared with expected values on the basis of age and years since menopause. In these patients we found that the bone deficit in the distal forearm was greater than in the spine, and 8 patients had already suffered one or more peripheral fractures. This suggests that postmenopausal women with mild, asymptomatic hypercalcemia of primary hyperparathyroidism are likely to be relatively more predisposed to peripheral than vertebral fractures, which is clear evidence of the need for treatment to prevent bone loss in these patients.

Modification and validation of a single-isotope radiocalcium absorption test

This study was done to establish and allow for the influence of body weight on plasma radioactivity after administering radiocalcium to measure calcium absorption.

METHODS

We administered 5 microCi 45Ca in 20 mg of calcium carrier in 250 ml distilled water to 103 premenopausal volunteers over the age of 40 yr, after an overnight fast. Venous blood was withdrawn when the dose was given (to serve as a blank) and exactly 60 min later, and the counts were determined in a liquid scintillation counter. After the exclusion of three outliers, the fraction of the administered dose per liter of plasma at 60 min was a curvilinear inverse function of body weight and a positive linear function of the reciprocal of body weight, with an r value of 0.45 (p < 0.001). This latter relationship then was used to correct the plasma radioactivity to a standard body weight of 65 kg, in which the volume of distribution of the dose was assumed to be 10 liters. This yielded the estimated fraction of the dose circulating at 1 hr, which then was converted into a fractional absorption rate from our previously published equation.

RESULTS

In the 100 volunteers, the mean value of the radiocalcium absorption rate (termed alpha2, to distinguish it from our original calculation) was 0.75/hr, with 98 of the 100 values falling between 0.30 and 1.20. The value alpha2 was significantly related to serum calcitriol in these 100 volunteers (r = 0.29; p = 0.003) and in 89 normal postmenopausal women (r = 0.46; p < 0.001). It also was significantly related to the 24-hr urine calcium in the same 89 women (r = 0.48; p < 0.001) and to net calcium absorption corrected for intake in balance studies on another 103 postmenopausal women (r = 0.44; p < 0.001). In most respects, alpha2 was marginally superior to alpha1 but, unlike alpha1, was independent of body weight.

CONCLUSION

The modified low-carrier radiocalcium absorption test is a valid indicator of calcium absorption status over a wide range of calcium intakes and is independent of body weight.

Gastric emptying and intragastric distribution of oil in the presence of a liquid or a solid meal

There is little information about gastric emptying of extracellular fat. A marker for liquid fat, 99mTc-(V)-thiocyanate, was used to compare gastric emptying and intragastric distribution of oil to that of aqueous liquid and solid meal components. Eight volunteers consumed 60 ml of 99mTc-labeled oil and 290 ml of 113m-In-labeled soup (total 505 kcal) on one day and 280 g 113mIn-minced beef (500 kcal), 60 ml 99mTc-labeled oil and 290 ml nonlabeled soup (505 kcal) on another day. In the oil/soup meal, gastric emptying of oil was slower than soup (50% emptying time 139.1 +/- 16.5 min versus 47.9 +/- 4.5 min, p less than 0.01). There was retention of oil in the proximal stomach (p less than 0.01) and retrograde movement of oil from distal into proximal stomach. In the oil/soup/beef meal, there was no difference in emptying of oil and beef from the total stomach (retention at 180 min 71.4% +/- 3.4% versus 58.3% +/- 7.6%, ns), but more oil was retained in the proximal stomach and more beef was retained in the distal stomach (p less than 0.01). The emptying rate of oil in the oil/soup meal was about twice that for oil consumed in the other meal. There was no difference between the two meals in the number of calories emptied in the first 180 min. These results demonstrate major differences in the intragastric distribution of oil compared to solid and aqueous liquid meals.

Effect of increasing the caloric/osmotic content of the liquid component of a mixed solid and liquid meal on gastric emptying in obese subjects

A dual isotope scintigraphic technique was used to assess the effect of increasing the caloric content of the liquid component of a mixed solid and liquid meal on gastric emptying in control and obese subjects. For the two test meals used gastric emptying of solid was significantly slower in the obese subjects compared to the control subjects. In both obese and control subjects the substitution of 25 per cent dextrose for water as the liquid component of the meal resulted in a significant delay of both solid and liquid emptying. The magnitude of this change was similar in obese and control subjects. The results suggest that the duodenal receptor mechanisms which slow gastric emptying are not defective in obesity.

Morally opposed? A theory of public attitudes and emerging military technologies

Military technology does not exist in a vacuum; it is mediated by difficult choices about development and use. Public attitudes influence these choices, but emerging technologies present a challenge: assessing public opinion without a clear picture of the technology's use. Focusing on autonomous weapon systems, we argue that attitude stability depends on moral conviction and concern with inherent characteristics or outcomes. Combining these dimensions into four reasoning categories creates a new framework for attitudes toward emerging technologies, validated with two Cooperative Congressional Election Study surveys. We find that moral conviction is prevalent, current opposition heterogeneous, and some attitudes depend on outcomes, especially civilian protection.

Diabetes distress and depression are independently associated with gastrointestinal symptoms in type 2 diabetes in Bangladesh

BACKGROUND AND AIMS

Gastrointestinal (GI) symptoms, common in type 2 diabetes (T2D), are typically bothersome, socially embarrassing, and impact negatively on quality of life. They may also contribute to diabetes distress (DD), but this has never been formally evaluated. We aimed to investigate the relationships between GI symptoms, DD and depressive symptoms in a large cohort of individuals with T2D in Bangladesh.

MATERIALS AND METHODS

1406 unselected T2D individuals (female 58.8%; mean age 51.0 ± 12.5 years) from four diabetes clinics in Bangladesh completed validated questionnaires evaluating GI symptoms (PAGI-SYM), DD (DDS-17) and depressive symptoms (PHQ-9).

RESULTS

31.1% of participants reported GI symptoms (36.2% females, 23.7% males), while 51.1% had elevated DD and 37.8% depressive symptoms. GI symptoms exhibited independent relationships with both DD and depressive symptoms, and their likelihood was higher among those with DD (OR: 3.6 [2.2-5.6] and with depressive symptoms (OR: 5.9 [3.5-9.9]).

CONCLUSIONS

GI symptoms are independently associated with both DD and depressive symptoms in people with T2D in Bangladesh.

Biochemical effects of a calcium supplement in osteoporotic postmenopausal women with normal absorption and malabsorption of calcium

Although calcium supplements are widely used to reduce bone resorption in osteoporosis, their beneficial effect is not conclusively established. We have studied the acute (after 12 h) effects of an oral calcium load (1 g) in a group of 35 osteoporotic postmenopausal women, comprising 19 subjects with normal absorption and 16 subjects with malabsorption of calcium. In the subjects with normal calcium absorption the fasting urinary total hydroxyproline/creatinine ratio fell from 0.021 to 0.017 (p less than 0.001), but in those with malabsorption of calcium it did not change significantly. This difference between the two groups was significant (p less than 0.01). These results indicate that an oral calcium load rapidly suppresses bone resorption in osteoporotic subjects with normal absorption of calcium, but not in those with malabsorption of calcium.

Abnormalities of gastric emptying in obese patients

The pattern of gastric emptying in 15 obese patients and 11 control subjects has been assessed using a double isotope technique for measuring solid and liquid emptying with a scintillation camera. In all studies solid emptying was characterized by a lag period (before food enters the duodenum) followed by linear emptying. Liquid emptying was faster than solid and was non-linear. In obese patients solid emptying was delayed due to prolongation of the lag period, and the duration of the lag period correlated with excess body weight. There was no significant change in liquid emptying in obese patients. In control subjects no relationship between gastric emptying rates and body weight was apparent.

Gastric emptying after gastric bypass

Gastric emptying of two test meals, consisting of ground beef and water and ground beef with 25 percent dextrose was measured with a scintigraphic technique in patients after gastric bypass surgery and in control subjects. Solid emptying was slower and liquid emptying was more rapid after gastric bypass and 25 percent dextrose emptied as rapidly as water. The pattern of gastric emptying after gastric bypass would favour more rapid initial absorption with liquid calories and may also be implicated in the dumping syndromes sometimes seen after gastric bypass.

Effects of erythromycin on gastric emptying, alcohol absorption and small intestinal transit in normal subjects

The effects of erythromycin on gastric emptying and intragastric distribution of a mixed solid/liquid meal, alcohol absorption and small intestinal transit were examined in eight male volunteers. Each subject received, in double-blind randomized order, either erythromycin as the lactobionate (3 mg.kg-1 i.v. over 20 min) or saline immediately before the consumption of a radioisotopically labeled test meal, which consisted of 330 g minced beef and 400 ml of orange juice containing ethanol (0.5 g.kg-1 body weight) and 10 g lactulose. Erythromycin increased the rate of total stomach emptying and proximal stomach emptying of both the solid and liquid components of the meal (p < 0.001), but slowed small intestinal transit (p < 0.01). Peak blood alcohol concentrations (p < 0.01) were higher after erythromycin, with a mean increase of 40%. There was a significant inverse relationship between peak blood alcohol concentrations and the 50% emptying time for the liquid component of the meal after saline (r = -0.70, p < 0.05), but not after erythromycin (r = -0.57, p < 0.1). The total area under the venous blood alcohol concentration time curve (i.e., total absorption) was greater (p < 0.01) after erythromycin. These results suggest that: faster emptying from the proximal stomach contributes to more rapid gastric emptying induced by erythromycin, erythromycin retards small intestinal transit and that erythromycin increases the total amount of alcohol absorbed as well as the rate of alcohol absorption. These latter effects are likely to reflect more rapid delivery of alcohol to the small intestine and reduced metabolism of alcohol by the gastric mucosa.