Mortality risk factors in community-dwelling, subjectively healthy, Swiss older adults: update after 8-years follow-up

BACKGROUND

Worldwide population is ageing, but little is known regarding risk factors associated with increased mortality in subjectively healthy, community-dwelling older adults. We present the updated results of the longest follow-up carried out on Swiss pensioners and we provide results on potential risk factors associated with mortality before the onset of the COVID-19 pandemic.

MATERIALS AND METHODS

Within the SENIORLAB study, we collected demographic data, anthropometric measures, medical history, and laboratory parameters of 1467 subjectively healthy, community-dwelling, Swiss adults aged ≥ 60 years over a median follow-up of 8.79 years. The variables considered in the multivariable Cox-proportional hazard model for mortality during follow-up were selected based on prior knowledge. Two separate models for males and females were calculated; moreover, we fitted the old model obtained in 2018 to the complete follow-up data to highlight differences and similarities.

RESULTS

The population sample included 680 males and 787 females. Age of participants ranged between 60 and 99 years. We experienced 208 deaths throughout the entire follow-up period; no patients were lost at follow-up. The Cox-proportional hazard regression model included female gender, age, albumin levels, smoking status, hypertension, osteoporosis and history of cancer within predictors of mortality over the follow-up period. Consistent findings were obtained also after gender stratification. After fitting the old model, female gender, hypertension, and osteoporosis still showed statistically significant independent associations with all-cause mortality.

CONCLUSIONS

Understanding the predictors of a healthy survival can improve the overall quality of life of the ageing population and simultaneously reduce their global economic burden.

TRIAL REGISTRATION

The present study was registered in the International Standard Randomized Controlled Trial Number registry: https://www.isrctn.com/ISRCTN53778569 (registration date: 27/05/2015).

Perianastomotic Irrigation With Passive Drainage Dramatically Decreases POPF Rate After High-risk Pancreaticoduodenectomy

Objective

To assess whether prophylactic irrigation and passive drainage of pancreatico-jejunal anastomosis could reduce leak and mortality rates after high-risk pancreaticoduodenectomies.

Background

Postoperative pancreatic fistula (POPF) is a life-threatening complication following pancreaticoduodenectomy. Several risk factors have been proposed likewise potential mitigation strategies. Regarding the latter, surgical drain policy remains a "hot topic." We propose an innovative approach to mitigate POPF and POPF-related mortality following high-risk pancreaticoduodenectomies.

Methods

One hundred fifty-seven patients undergoing pancreaticoduodenectomy between January 2012 and November 2021 were included in the study. Subjects with main pancreatic duct ≤ 3 mm and soft parenchyma were classified as high-risk for POPF development. Since August 2015, high-risk patients received prophylactic irrigation and drainage of the perianastomotic area. These patients were compared with risk-matched historical controls.

Results

We identified 73 high-risk patients. Of these, the 47 subjects receiving prophylactic perianastomotic irrigation showed significantly lower POPF rates (12.7% vs 69.2%, P < 0.001). Multivariate regression analysis confirmed the significant association between irrigation drainages and POPF (odds ratio 0.014, P = 0.01). Although not significant, mortality was lower in the irrigation group (4.2% vs 13.0%, P = 0.340). However, none of the fatalities in the irrigation-drainage group were POPF-related. No significant difference in length of hospital stay was observed between the 2 groups (18.0 vs 21.0 days, P = 0.091).

Conclusions

Irrigation and drainage of the perianastomotic area represents a powerful approach to reduce POPF and, potentially, mortality after high-risk pancreaticoduodenectomies.

Osteoporosis, diabetes, and hypertension are major risk factors for mortality in older adults: an intermediate report on a prospective survey of 1467 community-dwelling elderly healthy pensioners in Switzerland

BACKGROUND

Osteoporosis is an important morbidity factor for ageing populations in developed countries. However, compared to the amount of information available on diabetes and cardiovascular disease, little is known about the direct impact of osteoporosis on general mortality in older age.

METHODS

We obtained data from a prospective population-based cohort of pensioners from the SENIORLAB study who were subjectively healthy. The inclusion criteria were an age of at least 60 years and Swiss residence. We assessed and analysed clinical measures, voluntary reports, and laboratory values.

RESULTS

In total, 1467 subjects were included in the cohort. The mean follow-up time was 3.68 years (95% confidence interval, 3.64-3.71). The ages of the included participants ranged from 60 to 99 years. At follow-up, there were 1401 survivors, and 66 participants had died. According to the multivariate analysis (Cox regression), osteoporosis was the most important risk factor for all-cause mortality (hazard ratio, 4.46; 95% confidence interval, 1.82-10.91), followed by diabetes (hazard ratio, 2.17; 95% confidence interval, 1.04-4.52) and hypertension (hazard ratio, 1.81; 95% confidence interval, 1.09-3.03).

CONCLUSIONS

Osteoporosis is a major risk factor for all-cause mortality in a subjectively healthy senior population, followed by type 2 diabetes mellitus and hypertension. Osteoporosis should be more actively diagnosed in healthy pensioners before they develop osteoporosis-associated health incidents.

TRIAL REGISTRATION

The present study was registered in the International Standard Randomized Controlled Trial Number registry: ISRCTN53778569 .

Effect of a test meal on meal responses of satiation hormones and their association to insulin resistance in obese adolescents

OBJECTIVE

The role of gastrointestinal (GI) hormones in the pathophysiology of obesity is unclear, although they are involved in the regulation of satiation and glucose metabolism. To (i) examine glucagon-like peptide 1 (GLP-1), amylin, ghrelin, and glucagon responses to a meal in obese adolescents and to (ii) test which GI peptides are associated with insulin resistance are presented.

METHODS

A total of 16 obese (body mass index (BMI) ≥ 97th percentile for age and gender) and 14 control (BMI between 25th and 75th percentiles) adolescents were included. Subjects were instructed to eat a test meal (490 kcal). Plasma samples were collected for hormone and glucose analysis.

RESULTS

Obese adolescents were insulin resistant as expressed by the Homeostasis Model Assessment (HOMA) index and had significantly increased fasting glucagon and amylin levels compared to the control group (P = 0.003 and 0.044, respectively). In response to the meal, the increase in GLP-1 levels was reduced in obese adolescents (P < 0.001). In contrast, amylin secretion was significantly increased in the obese population compared to the control group (P < 0.005).

CONCLUSIONS

Obese adolescents have increased fasting glucagon and amylin levels and attenuated post-prandial GLP-1 concentrations compared with the control group. These factors could contribute to the metabolic syndrome.

Primary care emergency services utilization in German-speaking Switzerland: a population-based cross-sectional study

BACKGROUND

Traditionally, emergency consultations have been done by a general practitioner (GP) in Switzerland. Over the last years, there seems to have been a shift between general practice to hospital emergency ward utilisation. There are several local initiatives of general practitioners and hospitals to change the organisation of emergency care. To plan a new organisation form of emergency care, delivery should be based on population based data.

OBJECTIVE

The aim of the study was to investigate the epidemiology and distribution of emergency consultations of primary care in a hospital and in a practice of general practitioners. In addition, factors of clinical performance in emergency consultations are of great public health interest.

METHODS

For this survey, all emergency patient contacts of general practitioners from the catchment area of Bülach, serving 27 088 inhabitants, were assessed by a questionnaire during the fourth quarter of 2006. Sex, age, time, duration of the contact and triage diagnosis were assessed. In addition, all patients seen by the emergency ward at the local hospital were assessed. Contact rates and hospitalisation rates per 100 000 inhabitants were determined. In addition, a multiple linear regression model was performed to determine factors associated with consultation time as a marker for clinical performance.

RESULTS

Between October 1th and December 31th 2006, 1001 patient contacts were registered at the same time period in the hospital and general practice. The patient contact rate was 94.8 contacts per 100 000 inhabitants per day, and the hospitalisation rate was 9.1 patient per 100 000 inhabitants. Patients seen at the hospital were older than in general practice (41.2 ± 22.8 vs. 32.6 ± 26.3 years) and consultation and waiting time was longer in the hospital than consultation time with the GP (144.8 ± 106.5 vs. 19.6 ± 17.6 minutes).

CONCLUSION

Nearly 1 out of 1000 inhabitants were looking for emergency primary care help, and 10% of the patients were seen urgently by general practitioners and hospital staff and were hospitalised. These numbers are important information for planning emergency primary care facilities. The most prevalent triage diagnoses in practice are infections, traumatological reasons and ENT-problems, whereas in hospital the most frequent triage diagnosis is a traumatological disorder, followed by thoracic pain and infections. In addition, GP's treat patients more rapidly than a hospital does and treat patients in shorter time intervals.

Glucagon-like peptide-1 is involved in sodium and water homeostasis in humans

In previous studies with glucagon-like peptide-1 (GLP-1) we have observed that this peptide modulates fluid intake and increases renal sodium excretion in healthy volunteers and in patients with diabetes mellitus type 2. The effect of GLP-1 on thirst, water intake and on osmoregulation has, however, not been examined in detail in humans.

METHODS

Seventeen healthy male subjects were enrolled in two double-blind, placebo-controlled studies. In study part A, 8 volunteers participated in a protocol with an intravenous salt load of 26.7 +/- 0.9 g comparing the effect of an infusion of GLP-1 (1.5 pmol/kg x min) to isotonic saline (placebo). Sodium excretion and water intake were measured. In part B, 9 volunteers were challenged with an oral salt load of 27.7 +/- 0.5 g; sodium excretion and water intake were determined comparing an infusion of GLP-1 (1.5 pmol/kg x min) to isotonic saline (placebo). In part C, intestinal biopsies along the gastrointestinal tract were obtained from 14 healthy subjects. Expression of human GLP-1 receptor mRNA was measured by real-time polymerase chain reaction.

RESULTS

In study part A, an increase in renal sodium excretion was demonstrated: FeNa rose from 1.6 +/- 0.3 (placebo) to 2.7 +/- 0.2% (GLP-1; p = 0.0005). There was no difference in water consumption between the two treatments: 1,291 +/- 69 (saline) vs. 1,228 +/- 74 ml (GLP-1; p = 0.49). In part B, an oral salt challenge of 27.7 +/- 0.5 g led to an increased renal excretion of sodium during GLP-1: FeNa increased from 1.6 +/- 0.2% (placebo) to 2.0 +/- 0.2% (GLP-1; p = 0.012). In contrast to part A, oral water intake was reduced by 36% under GLP-1 treatment: 1,848 +/- 331 ml (placebo) vs. 1,181 +/- 177 ml (GLP-1; p = 0.0414). Three subjects in part B did not finish treatment with GLP-1 because of diarrhea. Human GLP-1 receptor mRNA expression was highest in the proximal human small intestine compared to terminal ileum and colon (p < 0.02).

CONCLUSIONS

GLP-1 acts on renal tissue reducing sodium absorption, probably via similar sodium transporters, which also may be localized in the gastrointestinal tract. This hypothesis needs to be confirmed by further studies.

MAPPING OF MULTIDRUG RESISTANCE GENE 1 AND MULTIDRUG RESISTANCE-ASSOCIATED PROTEIN ISOFORM 1 TO 5 mRNA EXPRESSION ALONG THE HUMAN INTESTINAL TRACT

Efflux transporters such as P-glycoprotein and multidrug resistance-associated proteins (MRPs) in the intestinal wall restrict intestinal drug transport. To overcome this limitation for enteral drug absorption, galenical targeting approaches have been proposed for site-specific luminal drug release in segments of the gut, where expression of the respective absorption-limiting transporter is minimal. Therefore, expression of multidrug resistance gene 1 (MDR1) and MRP1-5 was systematically investigated in 10 healthy subjects. Biopsies were taken from different segments of the gastrointestinal tract (from duodenum and terminal ileum, as well as ascending, transverse, descending, and sigmoid colon). Gene expression was investigated by quantitative real-time PCR (TaqMan). MRP3 appeared to be the most abundantly expressed transporter in investigated parts of the human intestine, except for the terminal ileum, where MDR1 showed the highest expression. The ranking of transporter gene expression in the duodenum was MRP3 >> MDR1 > MRP2 > MRP5 > MRP4 > MRP1. In the terminal ileum, the ranking order was as follows: MDR1 > MRP3 >> MRP1 approximately MRP5 approximately MRP4 > MRP2. In all segments of the colon (ascending, transverse, descending, and sigmoid colon), the transporter gene expression showed the following order: MRP3 >> MDR1 > MRP4 approximately MRP5 > MRP1 >> MRP2. We have shown, for the first time, systematic site-specific expression of MDR1 and MRP mRNA along the gastrointestinal tract in humans. All transporters showed alterations in their expression levels from the duodenum to sigmoid colon. The most pronounced changes were observed for MRP2, with high levels in the small intestine and hardly any expression in colonic segments. This knowledge may be useful to develop new targeting strategies for enteral drug delivery.

Interaction between GLP-1 and CCK-33 in inhibiting food intake and appetite in men

Glucagon-like peptide-1 (GLP-1) and CCK-33 were intravenously infused alone or in combination into normal weight men for 60 min before they were served a lunch of ham sandwiches, chocolate mousse, and orange juice. Infusion of GLP-1 (dose: 0.9 pmol·kg−1·min−1) or CCK-33 (dose: 0.2 pmol·kg−1·min−1) each reduced calorie intake of the test meal. However, simultaneous infusion of these peptide doses reduced calorie intake less than the sum of the peptides' individual effects. Infusions of the same doses of GLP-1 plus CCK-33 had neither individual nor interactive effects on meal size or calorie consumption. The combination of GLP-1 plus CCK-33 induced, however, a significant reduction in hunger feelings in the premeal period ( P = 0.036 vs. all other treatments). In summary, intravenous infusion of near physiological doses of CCK-33 and GLP-1 produced specific inhibitions of hunger feeling in men; the simultaneous infusion resulted in an infra-additive reduction in calorie consumption, rejecting thereby the hypothesis that the two peptides exert a positive synergistic effect on food intake compared with the effects observed with infusion of individual peptides. In conclusion, CCK and GLP-1 are meal-related satiety signals that are released from the gastrointestinal tract during food intake.

Glucagon-like peptide 1 (GLP-1) and eating

New information regarding gastrointestinal mechanisms that participate in the control of food intake has extended our understanding of appetite control. Although each new signaling pathway discovered in the gut is a potential target for drug development in the treatment of obesity, the growing number of such signaling molecules indicates that a highly complex process controls food intake. The present summary focuses on the role of glucagon-like peptide 1 (GLP-1) in this regulatory process. The different biological effects of GLP-1 (glucose-lowering properties, inhibition of appetite and food intake) provide a powerful impetus for development of GLP-1-based new drugs.

Glucagon-like peptide 1 induces natriuresis in healthy subjects and in insulin-resistant obese men

Glucagon-like peptide-1-(7-36)-amide (GLP-1) is involved in satiety control and glucose homeostasis. Animal studies suggest a physiological role for GLP-1 in water and salt homeostasis. This study's aim was to define the effects of GLP-1 on water and sodium excretion in both healthy and obese men. Fifteen healthy subjects and 16 obese men (mean body mass index, 36 kg/m2) were examined in a double-blind, placebo-controlled, crossover study to demonstrate the effects of a 3-h infusion of GLP-1 on urinary sodium excretion, urinary output, and the glomerular filtration rate after an i.v. 9.9-g salt load. Infusion of GLP-1 evoked a dose-dependent increase in urinary sodium excretion in healthy subjects (from 74 +/- 8 to 143 +/- 18 mmol/180 min, P = 0.0013). In obese men, there was a significant increase in urinary sodium excretion (from 59 to 96 mmol/180 min, P = 0.015), a decrease in urinary H+ secretion (from 1.1 to 0.3 pmol/180 min, P = 0.013), and a 6% decrease in the glomerular filtration rate (from 151 +/- 8 to 142 +/- 8 ml/min, P = 0.022). Intravenous infusions of GLP-1 enhance sodium excretion, reduce H+ secretion, and reduce glomerular hyperfiltration in obese men. These findings suggest an action at the proximal renal tubule and a potential renoprotective effect.

Increasing blood flow increases kt/V(urea) and potassium removal but fails to improve phosphate removal

BACKGROUND

Hyperphosphatemia and hyperkalemia are major determinants of morbidity and mortality in hemodialysis patients. Half of the dialysis population suffers from hyperphosphatemia which is now recognized as an important cardiovascular disease risk factor. It is, therefore, necessary to improve the removal of these molecules. In this study, we investigated the effect of enhancing blood flow on Kt/V for urea (Kt/Vu), potassium and phosphate removal.

METHODS

Thirteen patients were investigated in a randomized, cross-over, prospective study using 3 blood flows (Qb) of 200,250 and 300 ml/min which gave 39 standardized high-flux hemodialysis treatments. Effective blood flows were measured by ultrasonic flow meter. Quantification of delivered dialysis dose was performed by partial dialysate and ultrafiltrate collection for the determination of potassium and phosphate removal and by blood urea concentrations for determination of Kt/Vu.

RESULTS

Kt/Vu rose significantly from 1.10 +/- 0.14 to 1.22 +/- 0.14 and finally to 1.39 +/- 0.16 (p = 0.0001) with increasing Qb similar to the increase in potassium removal from 53.0 +/- 2.4 to 63.4 +/- 2.6 and to 74.2 +/- 3.8 mMol (p = 0.01). Phosphate removal only improved from 28.1 +/- 1.3 to 31.4 +/- 1.5 (p = 0.050) when Qb was increased from 200 to 250 ml/min but remained unchanged at 31.2 +/- 1.5 mMol (NS compared to phosphate removal at Qb = 250 ml/min) when Qb was increased to 300 ml/min.

CONCLUSIONS

Increasing delivered Kt/Vu and potassium removal with higher Qb fails to produce the same desired effect with phosphate removal during high-flux hemodialysis.

Estimating phosphate removal in haemodialysis: an additional tool to quantify dialysis dose

BACKGROUND

Half of the dialysis population suffers from hyperphosphataemia, which is now recognized as a major factor of haemodialysis (HD) morbidity and mortality. Current control is focussed on reducing dietary phosphate intake and diminishing absorption using phosphate binders, whereas control and quantification of phosphate removal by HD is undervalued. The aim of this prospective study was to develop a simple, bedside formula to estimate dialytic phosphate removal in stable HD patients.

METHODS

This was a prospective, randomized trial. Phosphate and urea elimination were assessed in a representative group of patients at two dialysis centres using randomly different dialysers (1.3-2.4 m(2)). Quantification was performed by partial dialysate collection, concentration measurements in blood and effluent dialysate spot samples, and Kt/V(urea) during standard high-flux HD. Multiple linear regression analyses were used in 77% of all data sets to generate an equation to predict phosphate removal. The formula was validated in the remaining 23% of data sets, in the same group of patients using a large capillary filter, and in diabetic patients treated with a small dialyser at different blood flows (200, 250, and 300 ml/min).

RESULTS

A formula allowing quantification of phosphate removal within one HD session was developed in 18 of 74 patients during 41 treatments (137 out of 177 data sets) and was determined as: M(PO4pred)=0.1t -17+50c(ds60)+11c(b60), where t is treatment time in min, c(ds60) and c(b60) are phosphate concentrations in dialysate and plasma measured 60 min into HD in mmol/l, and M(PO4pred) is estimated phosphate removed in mmol. The precision was remarkable (r(2)=0.92-0.94). The comparison of phosphate and Kt/V(urea) showed a significant association (r(2)=0.28), albeit with remarkable scatter.

CONCLUSIONS

We present the first approach to quantify phosphate removal during high-flux HD by a bedside formula. Only 28% of the variation in phosphate removal was explained by Kt/V(urea). It appears that other factors not adequately accounted for by Kt/V(urea) affect phosphate removal. Therefore, we propose an individual control and quantification of phosphate removal in HD.

A meta-analysis of the effect of glucagon-like peptide-1 (7-36) amide on ad libitum energy intake in humans

Seven studies have now been published pertaining to the acute effect of iv administration of glucagon-like peptide-1 (7-36) amide on ad libitum energy intake. In four of these studies energy intake was significantly reduced following the glucagon-like peptide-1 infusion compared with saline. In the remaining studies, no significant effect of glucagon-like peptide-1 could be shown. Lack of statistical power or low glucagon-like peptide-1 infusion rate may explain these conflicting results. Our aim was to examine the effect of glucagon-like peptide-1 on subsequent energy intake using a data set composed of subject data from previous studies and from two as yet unpublished studies. Secondly, we investigated whether the effect on energy intake is dose dependent and differs between lean and overweight subjects. Raw subject data on body mass index and ad libitum energy intake were collected into a common data set (n = 115), together with study characteristics such as infusion rate, duration of infusion, etc. From four studies with comparable protocol the following subject data were included if available: plasma concentrations of glucagon-like peptide-1, subjective appetite measures, well-being, and gastric emptying rate of a meal served at the start of the glucagon-like peptide-1 infusion. Energy intake was reduced by 727 kJ (95% confidence interval, 548-908 kJ) or 11.7% during glucagon-like peptide-1 infusion. Although the absolute reduction in energy intake was higher in lean (863 kJ) (634-1091 kJ) compared with overweight subjects (487 kJ) (209-764 kJ) (P = 0.05), the relative reduction did not differ between the two groups (13.2% and 9.3%, respectively). Stepwise regression analysis showed that the glucagon-like peptide-1 infusion rate was the only independent predictor of the reduction in energy intake during glucagon-like peptide-1 (7-36) amide infusion (r = 0.4, P < 0.001). Differences in mean plasma glucagon-like peptide-1 concentration on the glucagon-like peptide-1 and placebo day (n = 43) were related to differences in feelings of prospective consumption (r = 0.40, P < 0.01), fullness (r = 0.38, P < 0.05), and hunger (r = 0.26, P = 0.09), but not to differences in ad libitum energy intake. Gastric emptying rate was significantly lower during glucagon-like peptide-1 infusion compared with saline. Finally, well-being was not influenced by the glucagon-like peptide-1 infusion. Glucagon-like peptide-1 infusion reduces energy intake dose dependently in both lean and overweight subjects. A reduced gastric emptying rate may contribute to the increased satiety induced by glucagon-like peptide-1.

Role of gender upon basal and postprandial systemic and splanchnic haemodynamics in humans

BACKGROUND

Food intake, accompanied by systemic and splanchnic haemodynamic changes, has only been studied in males. The extent to which splanchnic postprandial hyperaemia shows gender differences is unknown.

METHODS

We tested 1) the splanchnic hyperaemic response to food in females and 2) whether postprandial haemodynamic changes show gender differences. Twenty-four healthy women (aged 20-35 years) and 20 healthy men (aged 21-34 years) participated in the study. A liquid test meal (Ensure plus, 1.5 kcal/ml) was perfused intraduodenally for 75 min through an enteral feeding tube at a rate of 3 ml/min after a 45-min basal period. Blood flow parameters were measured using Echo-Doppler technology.

RESULTS

Basal diastolic arterial blood pressure was significantly (P < 0.05) lower in females (66+/-2 versus 72+/-2 mmHg), whereas heart rate was the same (58+/-2 b/min, ns). Postprandially, diastolic blood pressure fell, but reached significance only in males (-10+/-3 mmHg; P < 0.05). Mean velocity in the superior mesenteric artery (SMA) was significantly (P < 0.05) higher in females compared to males at baseline (47+/-3 versus 39+/-2 cm/s), whereas maximal postprandial changes were similar (64+/-6 versus 56+/-6 cm/s, ns). Volume flow in the portal vein (PV) at baseline was 656+/-29 and 716+/-35 ml/min females and males, respectively (ns between gender). Maximal postprandial changes amounted to 808+/-86 and 884+/-107 ml/min, respectively (ns).

CONCLUSIONS

1) Perfusion of a liquid test meal induces significant increases in flow parameters in the SMA and PV in both genders. 2) These changes are partly paralleled by alterations in systemic haemodynamics. 3) Postprandial splanchnic flow parameters are qualitatively and quantitatively not different between genders.

Low-potassium and glucose-free dialysis maintains urea but enhances potassium removal

BACKGROUND

The influence of potassium (K) removal on dialysis efficiency as measured by urea elimination is not clear. In this prospective, randomized, cross-over study we investigated the magnitude of K removal and its effect on urea (u) elimination during high-flux haemodialysis (HD).

METHODS

Twelve stable, non-diabetic HD patients were investigated during three one-week standardized HD periods (1.8 m(2) high-flux polysulphone dialyser, treatment time 240 min, Qb = 300 ml/min, Qd = 500 ml/min, dialysate without glucose, bicarbonate 40 mmol/l), using dialysates containing 0 (0K), 1 (1K), and 2 (2K) mmol/l of K. Mass removal of K (M(K)) and u (M(U)) were measured during the mid-week treatment by partial dialysate collection. Urea reduction rate (URR) and Kt/V were determined.

RESULTS

0K, 1K and 2K treatments were perfectly comparable. Plasma K (PK) continuously declined reaching stable concentrations after 180 min. While 0K dialysate removed 117.1 mmol, 80.2 and 63.3 mmol (P < 0.001) were removed by 1K and 2K baths respectively. M(U) was not influenced by M(K) (r = 0.22) and amounted to 491.1 (0K), 508.6 (1K), and 506.2 (2K) mmol (NS) respectively. Accordingly, urea clearance, URR and Kt/V were constant during 0K, 1K and 2K treatments.

CONCLUSIONS

Potassium-free dialysate significantly enhances potassium elimination. Potassium removal has no influence on urea elimination. High potassium removal, when needed, does not impair dialysis efficiency as measured by urea kinetics in high-flux, glucose-free, 40 mmol/l bicarbonate HD.

Interaction between CCK and a preload on reduction of food intake is mediated by CCK-A receptors in humans

Cholecystokinin (CCK) interacts with neural signals to induce satiety in several species, but the mechanisms are unclear. We therefore tested the hypothesis that alimentary CCK (CCK-A) receptors mediate the interaction of CCK with an appetizer on food intake in humans. CCK octapeptide (CCK-8, 0.75 microgram infused over 10 min) or saline (placebo) with concomitant infusions of saline (placebo) or loxiglumide, a specific CCK-A antagonist, was infused into 16 healthy men with use of a double-blind, four-period design. All subjects received a standard 400-ml appetizer (amounting to 154 kcal) but were free to eat and drink thereafter as much as they wished. The effect of these infusions on feelings of hunger and satiety and on food intake was quantified. CCK-8 induced a reduction in calorie intake (P < 0.05) compared with saline. Furthermore, a decrease in hunger feelings (P < 0.05, saline-CCK-8 vs. all other treatments) and an increase in fullness were observed. These effects were antagonized for hunger and fullness by loxiglumide. We conclude that CCK-8 interacts with an appetizer to modulate satiety in humans. These effects are mediated by CCK-A receptors.

Inhibition of food intake in response to intestinal lipid is mediated by cholecystokinin in humans

Intraduodenal fat inhibits gastric emptying and exerts early satiation in animals and humans, but it is not clear whether the effects are mediated by cholecystokinin (CCK) in humans. Here, we tested whether CCK-A receptors mediate the inhibition of fat on food intake. Two sequential, double-blind, crossover studies were performed in 24 male subjects. First, subjects received either intraduodenal fat or saline together with a preload of either water or banana shake. Second, 12 subjects received either intraduodenal fat or saline perfusion plus a concomitant infusion of saline or loxiglumide, a specific CCK-A receptor antagonist, together with a preload of banana shake. In both studies, subjects were free to eat and drink as much as they wished. Fat induced a reduction in calorie intake (P < 0.05) compared with controls. Furthermore, a decrease in hunger feelings was observed. Infusion of loxiglumide abolished the effects of fat. Duodenal fat interacts with an appetizer to modulate energy intake in humans. This effect is mediated by CCK-A receptors.

Hemodiafiltration--a new treatment option for hyperphosphatemia in hemodialysis patients

BACKGROUND

Hemodiafiltration is used to increase the convective transport and thereby the elimination of small and middle molecules, mainly beta2-microglobulin (beta2-M) across the dialysis membranes. There is little information concerning urea, creatinine, beta2-M and principally phosphate kinetics during hemodiafiltration in vivo. In this prospective study, we evaluated the transmembrane solute mass removal (TSR) and clearance (Kd) of urea, creatinine and phosphate as well as serum beta2-M reduction rate (beta2-MRR) and collected beta2-M in dialysate plus ultrafiltrate during high-flux hemodialysis (HD) and post-dilutional hemodiafiltration (HDF).

PATIENTS AND METHODS

16 patients were studied using a polysulfone capillary filter (1.6 m2 surface area, 40 microm fiber internal diameter and 200 microm, wall thickness) during 2 one-week periods: first week HD 1.6 m2 and second week HDF 1.6 m2. Treatment time was 4 hours, blood flow rate 300 ml/min with constant dialysate and ultrafiltration rates for HD and HDF periods. TSR, Kd, beta2-MRR and beta2-M collection were assessed during the mid-week treatment. In a second part of the study, we repeated the same protocol using a second high-flux polysulfone capillary filter (2.4 m2 surface area, 30 microm fiber diameter and 150 microm wall thickness).

RESULTS

TSR and Kd of urea and creatinine were not improved by HDF, however, HDF increased TSR and Kd of phosphate. Phosphate clearance rose from 120 (HD 1.6 m2) to 159 (HDF 1.6 m2) (p < 0.005) and from 146 (HD 2.4 m2) to 206 (HDF 2.4 m2) (p < 0.005) ml/min. Beta2-MRR increased from 64.1 +/- 8.6 to 77.7 +/- 8.2% (p < 0.005) and from 75.0 +/- 5.1 to 82.9 +/- 8.5% (p < 0.005) during HDF 1.6 m2 and HDF 2.4 m2, respectively. Collected beta2-M remained unchanged. This discrepancy seems to be due to an enhanced beta2-M adsorption to the polysulfone membrane during HDF.

CONCLUSION

Our results provide a strong evidence that HDF has no advantage over HD with respect to urea and creatinine removal in vivo. However, HDF did improve the elimination of phosphate and should be considered as an additional treatment option for hyperphosphatemia in dialysis patients. HDF improves significantly the elimination of beta2-M.

Glucagon-like peptide-1 promotes satiety and reduces food intake in patients with diabetes mellitus type 2

Glucagon-like peptide-1-(7-36) amide (GLP-1) is an incretin hormone of the enteroinsular axis. Recent experimental evidence in animals and healthy subjects suggests that GLP-1 has a role in controlling appetite and energy intake in humans. We have therefore examined in a double-blind, placebo-controlled, crossover study in 12 patients with diabetes type 2 the effect of intravenously infused GLP-1 on appetite sensations and energy intake. On 2 days, either saline or GLP-1 (1.5 pmol. kg-1. min-1) was given throughout the experiment. Visual analog scales were used to assess appetite sensations; furthermore, food and fluid intake of a test meal were recorded, and blood was sampled for analysis of plasma glucose and hormone levels. GLP-1 infusion enhanced satiety and fullness compared with placebo (P = 0.028 for fullness and P = 0.026 for hunger feelings). Energy intake was reduced by 27% by GLP-1 (P = 0.034) compared with saline. The results demonstrate a marked effect of GLP-1 on appetite by showing enhanced satiety and reduced energy intake in patients with diabetes type 2.

Glucagon-like peptide-1: a potent regulator of food intake in humans

BACKGROUND/AIMS

Studies in animals suggest a physiological role for glucagon-like peptide-1-(7-36)-amide (GLP-1) in regulating satiety. The role of GLP-1 in regulating food intake in man has, however, not been investigated. Subjects-Sixteen healthy male subjects were examined in a double blind placebo controlled fashion.

METHODS

The effect of graded intravenous doses (0, 0.375, 0.75, and 1.5 pmol/kg/min) of synthetic human GLP-1 on food intake and feelings of hunger and satiety was tested in healthy volunteers.

RESULTS

Graded GLP-1 infusions resulted in a dose dependent reduction in food intake (maximal inhibition 35%, p<0.001 v control) and a similar reduction in calorie intake (32%; p<0.001). Fluid ingestion was also reduced by GLP-1 (18% reduction, p<0.01). No overt side effects were produced by GLP-1, but subjects experienced less hunger and early fullness in the period before a meal during GLP-1 infusion at the highest dose (p<0.05).

CONCLUSIONS

Intravenous infusions of GLP-1 decrease spontaneous food intake even at physiological plasma concentrations, implying an important role for GLP-1 in the regulation of the early satiety response in humans.

Aortic valve stenosis as a cause of major systemic embolism--a case report

This is the first documented case of a patient suffering from embolic occlusion of the left brachial artery caused by a large embolus growing on a lesion of a stenosed calcified aortic valve. Supported by their own additional observations the authors suggest that severe calcified aortic valve stenosis should be considered as an indication for anticoagulation in the period before surgical valve replacement.

Effect of intravenous human gastrin-releasing peptide on food intake in humans

BACKGROUND/AIMS

Bombesin and gastrin-releasing peptide (GRP) are closely related peptides. Both have been proposed to serve as a satiety signal in animals.

METHODS

To explore further the role of GRP in humans, its effects on satiety and eating behavior were investigated by infusion of GRP into healthy men at three dosages (10, 40, and 160 pmol/kg per hour) and compared with saline infusions.

RESULTS

GRP produced a significant reduction in calorie intake (P < 0.05) but only a 19% (nonsignificant) reduction in food intake. Fluid ingestion was not affected by GRP. No overt side effects were produced by GRP, but subjects experienced d less hunger and early fullness in the premeal period during GRP infusion but not when receiving saline (P < 0.05-0.01).

CONCLUSIONS

This study shows that intravenous infusions of GRP can decrease spontaneous food intake at concentrations that produce physiological effects, such as stimulation of acid or pancreatic secretion or gallbladder contraction. The data imply that GRP-like peptides can act as satiety signals in humans, confirming data previously reported in animals.

Distinct hemodynamic and gastric effects of human CGRP I and II in man

The human calcitonin gene-related peptides I and II (or alpha and beta) (CGRP I and II) are encoded by two different genes, but they have 34 of the 37 amino acid residues in common. Human CGRP I more potently stimulated blood flow through the skin and carotid artery (p less than 0.01), and the heart rate (p less than 0.05), and plasma renin activity and aldosterone secretion than human CGRP II (p less than 0.02). Inhibition of pentagastrin-stimulated gastric acid output, on the other hand, was only obtained with CGRP II. The separate effects of human CGRP I and II on the cardiovascular and gastric systems are presumably mediated by different receptors or receptor pathways recognized by the two closely related neuropeptides.