Experimental infusion thrombophlebitis. Importance of the pH of glucose solutions

An experimental method is presented, which compares the tendency of different infusions to cause thrombophlebitis. It is based on a quantitative histological analysis of the inflammatory changes in the veins of rabbit ears after infusions under standardized conditions. By means of this method the inflammatory changes in the veins have been shown to be significantly less pronounced when the pH of glucose solutions is altered from 3.0 to 3.6. This pH change has been prescribed in the 1971 corrections to Pharmacopoea Nordica 1963. By complete neutralization of 5% glucose a further reduction of the damage to the veins has been obtained. For this purpose phosphate buffer is recommended.     

Experimental infusion thrombophlebitis. Importance of the infusion rate

The importance of the method of administration of acid glucose infusions for the venous inflammatory response has been investigated in two series of experimental trials. 60 ml of 5% glucose solution was administered into rabbit-ear veins in three ways: 1) continuously over 5 hours (slow infusion), 2) continuously over 1 hour (rapid infusion), 3) discontinuously during 2 x 30 minutes with an interval of 4 hours (discontinuous infusion). Microscopical examination of the veins revealed that the inflammatory changes were less pronounced after rapid and discontinuous infusions than after slow infusions.     

Effects of intravenously administered fructose and glucose on splanchnic amino acid and carbohydrate metabolism in hypertriglyceridemic men.

Splanchnic metabolism was studied in the fed state during prolonged intravenous administration (30 g/h) of either fructose or glucose to hypertriglyceridemic men who had been maintained on a high-carbohydrate diet for 2 wk. Splanchnic exchange of amino acids and carbohydrates was quantified by measurement of splanchnic flow and of blood or plasma arteriohepatic venous concentration gradients. Results obtained in subjects receiving fructose were compared with those obtained in (a) similar subjects receiving glucose and (b) postabsorptive controls maintained on isocaloric, balanced diets. Mean arterial plasma levels of alanine, glycine, serine, threonine, methionine, proline, valine, leucine, histidine, lysine, and ornithine were significantly higher in subjects given fructose than in those give glucose (P less than 0.05). The mean arterial concentration and splanchnic uptake of alanine were significantly higher in subjects given fructose than in postabsorptive controls, despite a significantly lower fractional extraction of alanine in the former (P less than 0.05). The mean arterial plasma levels of serine and ornithine were significantly lower in subjects receiving fructose than in postabsorptive controls (P less than 0.05). About half of the administered fructose or glucose was taken up in the splanchnic region, where approximately 15% was converted to CO2 and 10% to lactate. Half of the fructose taken up in the splanchnic region was converted to glucose released from the liver. The amount of hexose carbon remaining for hepatic synthesis of liquids in subjects given fructose was less than half of that of subjects given glucose. These studies demonstrate that fructose and glucose have divergent effects on amino acid metabolism and that during hypercaloric infusion of glucose (as with fructose), the human liver is a major site of lactate production.     

Metabolic effects of dietary fructose in diabetic subjects.

OBJECTIVE--To assess the metabolic effects of chronic dietary fructose consumption in diabetic subjects. RESEARCH DESIGN AND METHODS--Six type I and 12 type II diabetic subjects consumed, in random order, two isocaloric study diets for 28 days. In one diet, 20% of energy was derived from fructose. In the other diet, < 3% of energy came from fructose, and carbohydrate energy was derived primarily from starch. Both study diets were composed of common foods. All meals were prepared in a metabolic kitchen where all foods were weighed during meal preparation. RESULTS--Mean plasma glucose, urine glucose, and serum glycosylated albumin values were lower during the fructose diet than during the starch diet, but the differences achieved only marginal statistical significance. The day-28 value for mean plasma glucose was 12.5% lower (P = 0.03) during the fructose diet than during the starch diet. At days 14, 21, and 28, fasting serum cholesterol and LDL cholesterol were both significantly higher during the fructose diet than during the starch diet. The day-28 values for serum cholesterol and LDL cholesterol during the fructose diet were 6.9% (P = 0.008) and 10.9% (P = 0.002) higher, respectively, than the corresponding values during the starch diet. No differences were observed between the study diets in fasting serum HDL cholesterol, fasting serum triglycerides, peak postprandial serum triglycerides, or fasting serum lactate. Peak postprandial serum lactate was significantly higher during the fructose diet. Type I and type II diabetic subjects responded to the diets in a consistent way, but type I subjects experienced significantly more hypoglycemia during the fructose diet than during the starch diet. CONCLUSIONS--A high-fructose diet may result in reduced glycemia in diabetic subjects but at the expense of increased fasting serum total and LDL cholesterol.     

Failure of common glycation assays to detect glycation by fructose.

Serum albumin was modified by in vitro glycation with either fructose or glucose, to see whether the common clinical assays for glycation were able to detect both fructose- and glucose-induced changes in protein structure in diabetes. Although fluorescence measurements showed that fructose causes far more protein damage than glucose, neither serum fructosamine (SFA) nor phenylboronate affinity (PBA) glycation assays reflected these changes. The SFA method implied that fructose causes only about 5% of the glycation induced by glucose; with PBA the proportion was 25%. The thiobarbituric acid- and periodate-based assays also greatly underestimated the true extent of fructation. We discuss these discrepancies with respect to the underlying chemistry, emphasizing the difference between aldehydic and ketonic Amadori products (exemplified by fructose and glucose derivatives, respectively). The implications for detecting fructose-induced secondary diabetic complications are also discussed.     

Comparison of various submucosal injection solutions for maintaining mucosal elevation during endoscopic mucosal resection

BACKGROUND AND STUDY AIMS: One of the major complications of endoscopic mucosal resection (EMR) for gastrointestinal tumors is perforation, and the most effective way of preventing perforation is to elevate the lesion sufficiently by endoscopic injection of fluid into the submucosa. MATERIALS AND METHODS: In order to compare the lesion-lifting properties of several different solutions, 1 ml of each of the following solutions was injected into the submucosa of the resected porcine stomach: normal saline, 3.75 % NaCl, 20 % dextrose water, 10 % glycerin with 0.9 % NaCl plus 5 % fructose, and two sodium hyaluronate (SH) solutions. RESULTS: Significantly higher initial elevation was produced by both SH solutions, and it remained higher than that achieved by the other solutions at all times. Hypertonic solutions, especially 10 % glycerin with 0.9 % NaCl plus 5 % fructose, tended to produce and maintain greater mucosal elevation than normal saline, but the difference was not significant. CONCLUSIONS: SH solutions were the most suitable ones for producing and maintaining long-term mucosal elevation, while the superiority of hypertonic solutions over normal saline was not clearly demonstrated.     

The effects of sucrose, fructose, and high-fructose corn syrup meals on plasma glucose and insulin in non-insulin-dependent diabetic subjects

We have previously shown that fructose and sorbitol given with a standard meal cause less increment in plasma glucose than sucrose and high fructose corn syrup (HFCS) in patients with NIDDM. However, there was no direct comparison of sucrose with HFCS. Sixteen men and one woman aged 54-67) with NIDDM were given either 35 g sucrose, 35 g fructose, or 43.75 g HFCS containing 35 g carbohydrate as part of a 400-calorie test meal. Blood samples were obtained at frequent intervals up to 3 h and were analyzed for glucose and insulin. As compared with a fructose meal, the mean increment in plasma glucose (delta PG) after a sucrose meal was significantly higher at 45 min and after an HFCS meal it was significantly higher at 30 and 45 min, but sucrose and HFCS meals did not differ. When delta PGs were compared in nine patients with basal PG greater than 140 mg/dl and in eight patients with basal PG less than 140 mg/dl, differences in delta PG after sucrose and HFCS versus fructose meals became more significant but still did not differ from each other. The integrated total areas under the delta PG curves after sucrose, HFCS, and fructose meals were not statistically different. However, the areas under the curves up to 90 min after sucrose and HFCS meals, which did not differ, were greater than the fructose meal. The mean delta IRI after sucrose meals was markedly elevated at 45, 60, and 75 min (P less than 0.05) and after HFCS meals at 45 min as compared with fructose meals.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparative studies on the use of equimolar 14C-labeled glucose and fructose infusions in normal subjects and patients with liver cirrhosis

In 11 normal subjects (NS) and 12 patients with liver cirrhosis (LC) the utilisation of 14C-glucose and 14C-fructose infusions (0.75 g/kg/h for 4 h) was compared. There were nor relevant side effects. Lactate and pyruvate were in both groups during fructose infusion slightly increased compared to glucose infusion. The free fatty acids were significantly decreased. The serum glucose level rose more in LC than in NS when given fructose infusion. During glucose and fructose infusion in LC higher insulin concentrations were calculated than in NS. 15 min after infusion of 14C-fructose 20% of the total serum activity was 14C-glucose, after 2 to 4 h the level was 30%. Differences between NS and LC were not found to be significant. The specific activity of 14CO2 was the same in both the 14C-glucose infusion and the 14C-fructose infusion. The glucose oxidation was impaired in LC, but not the 14CO2-exhalation during infusion of 14C-fructose. Unimpaired 14CO2-exhalation, and normal utilisation and conversion to glucose are arguments for the use of fructose in infusion treatment of cirrhotics.     

Differential effects of honey, sucrose, and fructose on blood sugar levels

It is now recognized that dietary carbohydrate components influence the prevalence and severity of common degenerative diseases such as dental problems, diabetes, heart disease and obesity. Fructose and sucrose have been evaluated and compared to glucose using glucose tolerance tests, but few such comparisons have been performed for a "natural" sugar source such as honey. In this study, 33 upper trimester chiropractic students volunteered for oral glucose tolerance testing comparing sucrose, fructose and honey during successive weeks. A 75-gm carbohydrate load in 250 ml of water was ingested and blood sugar readings were taken at 0, 30, 60, 90, 120 and 240 minutes. Fructose showed minimal changes in blood sugar levels, consistent with other studies. Sucrose gave higher blood sugar readings than honey at every measurement, producing significantly (p less than .05) greater glucose intolerance. Honey provided the fewest subjective symptoms of discomfort. Given that honey has a gentler effect on blood sugar levels on a per gram basis, and tastes sweeter than sucrose so that fewer grams would be consumed, it would seem prudent to recommend honey over sucrose.     

Do fat emulsions protect against infusion thrombophlebitis?

The clinical experience that a fat emulsion (Intralipid^®) protects the vein against infusion thrombophlebitis caused by an amino acid solution (Aminosol^®) was controlled by an experimental method based on a quantitative histological analysis of the inflammatory changes observed in the veins of rabbit ears after infusions. In a controlled blind study, sequential analysis failed to reveal any difference in the histological changes which developed after infusion of Aminosol alone and Aminosol plus Intralipid. In a second series of experiments in which Intralipid was compared with 0.9% NaCl it was demonstrated that the fat emulsion alone gave rise to considerable inflammatory changes in the veins.     

Depletion of liver adenosine phosphates and metabolic effects of intravenous infusion of fructose or sorbitol in man and in the rat

Summary. 1. The effect of parenteral administration of fructose and sorbitol on hepatic adenosine phosphates (AP) and intermediates of carbohydrate metabolism was examined in man and rat.—2. Intravenous injection of fructose rapidly decreases ATP, total adenosine phosphates (AP), and inorganic phosphate in the liver of fed male and female rats. The depletion in hepatic ATP and total AP is also observed in the regenerating rat liver following partial hepatectomy. Equimolar administration of sorbitol has the same effect on liver AP has that observed following fructose, while glucose administration produces no significant changes.—3. In man i.v. infusion of 0.6–0.8 g/kg body weight of fructose or sorbitol reduces hepatic ATP to about 50 %, and total AP to about 65 % of initial values. Glucose has no effect. Blood AP content is not affected by intravenous infusion of 500 ml of 10 % fructose in man.—-4. Fructose distinctly increases the content of various hexose phosphates and triose phosphates in the liver of man. Fructose-1-phosphate accumulates 4-to 5-fold and α-glycerophosphate 3-fold during infusion of 0.6–0.8 g/kg body weight of fructose within 30 minutes.—5. RNA-synthesis in the regenerating rat liver following partial hepatectomy as neasured by incorporation of 6-¹⁴C-orotic acid is distinctly inhibited by i. v. injection of 1.6 g of fructose kg. The incorporation rate of 1-¹⁴C-D, L-leucine into rat liver protein drops to 35 % of initial levels within 10 minutes after the same amount of fructose, whereas glucose has no inhibitory effect.—6. Both ATP and Pi are important inhibitors of AMP degradation. Thus the drop in total AP content can be explained by the increased breakdown of the latter. This assumption is supported by the observation that injection of fructose plus equimolar amounts of Pi reduces the decrease in total AP, but not in ATP content. The concentration of the final product of AMP degradation, uric acid, increases distinctly following i. v. fructose administration in man.—7. These results indicate that in clinical medicine infusion of large doses of fructose or sorbitol have more disadvantages than advantages compared to glucose.     

Frozen desserts and glycemic response in well-controlled NIDDM patients

Fructose is known to elicit a lower glycemic response than sucrose, and high-fructose desserts have been recommended for a diabetic diet. We compared a cholesterol-free tofu-based frozen dessert (TFD) containing high-fructose corn syrups with a dairy-based sucrose-sweetened ice cream (IC). Six male and six female non-insulin-dependent diabetic patients (mean age 51 yr, mean ideal body weight 143%, fasting blood glucose less than 160 mg/dl) with well-controlled diabetes and managed on oral hypoglycemic agents were studied. Subjects underwent three trials. In the first trial they ingested 50 g glucose, and in the next two trials they ingested 50-g carbohydrate equivalents of either TFD or IC in random sequence. Venous blood was drawn at intervals during the 3-h trials for glucose and insulin determinations. Fasting plasma glucose was not statistically different between IC and TFD trials (130 vs. 121 mg/dl). Peak glucose responses were at 120 min in both trials (190 mg/dl for IC and 222 mg/dl for TFD), with those for TFD being significantly higher (P less than 0.01). Mean glucose area and glycemic index for TFD were significantly greater than for IC (P less than 0.01 and P less than 0.03, respectively). There was no significant difference between mean insulin areas. In summary, the TFD, which contains soybean curd and high-fructose corn syrup, might have been expected to produce more satisfactory postprandial blood glucose levels than IC, which contains sucrose, yet a higher glycemic response was elicited. This is related to the substantial amount of total glucose in this "fructose" dessert.(ABSTRACT TRUNCATED AT 250 WORDS)     

Moderate Amounts of Fructose Consumption Impair Insulin Sensitivity in Healthy Young Men: A randomized controlled trial

OBJECTIVE

Adverse effects of hypercaloric, high-fructose diets on insulin sensitivity and lipids in human subjects have been shown repeatedly. The implications of fructose in amounts close to usual daily consumption, however, have not been well studied. This study assessed the effect of moderate amounts of fructose and sucrose compared with glucose on glucose and lipid metabolism.

RESEARCH DESIGN AND METHODS

Nine healthy, normal-weight male volunteers (aged 21–25 years) were studied in this double-blind, randomized, cross-over trial. All subjects consumed four different sweetened beverages (600 mL/day) for 3 weeks each: medium fructose (MF) at 40 g/day, and high fructose (HF), high glucose (HG), and high sucrose (HS) each at 80 g/day. Euglycemic-hyperinsulinemic clamps with [6,6]-²H₂ glucose labeling were used to measure endogenous glucose production. Lipid profile, glucose, and insulin were measured in fasting samples.

RESULTS

Hepatic suppression of glucose production during the clamp was significantly lower after HF (59.4 ± 11.0%) than HG (70.3 ± 10.5%, P < 0.05), whereas fasting glucose, insulin, and C-peptide did not differ between the interventions. Compared with HG, LDL cholesterol and total cholesterol were significantly higher after MF, HF, and HS, and free fatty acids were significantly increased after MF, but not after the two other interventions (P < 0.05). Subjects’ energy intake during the interventions did not differ significantly from baseline intake.

CONCLUSIONS

This study clearly shows that moderate amounts of fructose and sucrose significantly alter hepatic insulin sensitivity and lipid metabolism compared with similar amounts of glucose.In the U.S., the consumption of fructose increased by more than 25% between 1970 and 1997 as the total sugar intake of the population rose (1). During the same period, the prevalence of obesity rose dramatically, paralleling the increase in fructose consumption and the introduction of high-fructose corn syrup (2). Whether there is a causal relationship between those developments, however, remains unclear. Total fructose consumption from natural and added sources, estimated from food disappearance data, was estimated to be 97 g/person/day in 1997 in the U.S. (1) and 83 g/person/day in 1998 in Switzerland (3).Epidemiologic and intervention studies of fructose and other caloric sweeteners have shown detrimental effects on health. In a cross-sectional study in U.S. adults, for example, the consumption of caloric sweeteners was associated with increased dyslipidemia (4) and in the Health Professionals Follow-up Study, high intakes of sugar-sweetened beverages (SSB) increased the risk for type 2 diabetes (5). Intervention trials have provided evidence that high- to very high–fructose doses led to increases in de novo lipogenesis, blood triglycerides, and hepatic insulin resistance (6–8).Not all of these studies found consistent effects for all parameters, however. In the study by Lê et al. (6), where 1.5 g fructose/kg body weight were consumed during a 4-week period, fasting lipids and glucose were affected, but insulin resistance, as determined by a euglycemic-hyperinsulinemic clamp, did not change. However, their study only tested fructose, without comparison with other sugars. Furthermore, relatively high amounts of fructose were consumed in most of these studies, reaching up to 25% of total energy intake. In a recent intervention study in healthy Swiss men, we found adverse effects of low to moderate amounts of fructose—but also glucose and sucrose—on fasting glucose and inflammatory markers, whereas only beverages containing fructose seemed to negatively affect LDL particle size. Even though fasting glucose was altered, none of the interventions showed any effect on glucose tolerance or on indices of insulin sensitivity calculated during an oral glucose tolerance test (9).The aim of the current study was therefore to assess the effect of moderate amounts of fructose and sucrose, compared with the same amounts of glucose, specifically on hepatic insulin sensitivity but also on lipid profiles of healthy human subjects using euglycemic-hyperinsulinemic clamps with [6,6]-²H₂ labeled glucose.     

The presence of furan derivatives in patients receiving fructose-containing solutions intravenously

Several commercially available fructose-containing solutions for intravenous nutrition have been shown, using gas chromatography-mass spectrometry, to contain considerable amounts (up to 1.2 g per liter) of 5-hydroxymethyl-2-furfural, 2-(2'hydroxyacetyl)-furan, levulinic acid and 2-keto-3-deoxyglucose. These decomposition products of fructose are formed if the pH has been kept at less than 4.0 during the sterilisation process.Patients receiving furan-containing sugar solutions intravenously convert about 50% of the 5-hydroxymethyl-2-furfural into 5-hydroxymethyl-2-furoic acid and furan-2,5-dicarboxylic acid, which are excreted in the urine. The remaining part of the aldehyde and the 2-(2'-hydroxyacetyl)-furan (after in vivo oxidation) are probably bound to thiol and amino groups of proteins and enzymes. The furan derivatives present in sterile fructose-containing solutions may consequently cause harmful effects when infused intravenously in humans. It is emphasised that the pH of sugar solutions should be more carefully controlled than appears to be common practice today, so that unwanted decomposition products of fructose can be avoided in mixtures used for parenteral nutrition.     

Acceleration of fructose mediated collagen glycation

The effect of fructose on the formation of advanced Maillard reaction products which show fluorescence and have crosslinking was investigated. Type I collagen was added to various concentrations of glucose and fructose which were then incubated at 37 degrees C for 4 weeks. The level of furosine and the fluorescence intensity both increased in direct proportion to glucose and fructose levels and to the duration of incubation. Incubation with fructose produced less furosine but more intense fluorescence than incubation with glucose. Furthermore, collagen was significantly less soluble after incubation with fructose than after incubation with glucose. These results suggest that fructose in the polyol pathway plays an important role in the formation of advanced Maillard products.     

Glucose absorption from maltotriose and glucose oligomers in the human jejunum

The jejunal absorption of glucose from (1-4)-linked glucose oligomers including maltotriose has been compared with that from free glucose and sucrose in normal subjects. A steady-state perfusion technique in vivo was used to study proximal jejunal assimilation of isotonic sugar-saline solutions isocaloric with 140 mmol/l glucose. Endogenous alpha-amylase was excluded from the test segment by proximal balloon occlusion. The glucose oligomer mixture consisted mainly of maltotriose, maltotetraose, maltopentaose and maltoheptaose. Glucose absorption was significantly faster from maltotriose alone and from the glucose oligomer mixture than from 140 mmol/l glucose controls, whereas glucose absorption from 70 mmol/l sucrose was similar to that from 70 mmol/l glucose plus 70 mmol/l fructose. Hydrolysis in vivo of maltotriose, the oligomer mixture and sucrose were similar, indicating that capture of glucose released by brush border sucrose hydrolysis was less efficient than that associated with (1-4)-linked oligomer hydrolysis. This suggests that the stoichiometric relationship of the active hydrolysis sites for sucrose to the glucose transport system is less advantageous than that of active sites for maltose hydrolysis. Hydrolysis of oligomers larger than maltohexaose may be rate limiting for glucose absorption in the absence of luminal amylase activity.     

Effects of Fructose and Glucose on Ethanol-Induced Metabolic Changes and on the Intensity of Alcohol Intoxication and Hangover

The effects of fructose and glucose on the metabolic changes induced by ethanol and on the intensity of alcohol intoxication and hangover were studied in 109 healthy male volunteers. After 10 hours of fasting, the subjects were given 1.75 g of ethanol per kg body wt during 3 hours under controlled laboratory conditions. Fructose or glucose were adminstered either simultaneously with ethanol or 12 hours later during the hangover period. The intensity of alcohol intoxication and hangover were estimated 10 times during the experimental period of 20 hours using subjective and objective rating scales. Sequential determinations of blood ethanol, acetaldehyde, glucose, lactate, free fatty acids, triglycerides, ketone bodies and capillary blood acid-base balance were also made during the experiment. Under these experimental conditions neither fructose nor glucose had any significant effect on the intensity of alcohol intoxication and hangover. The sugars also had no significant effect on the rate of ethanol elimination or on the blood acetaldehyde concentration during the course of the experiment. Blood glucose concentration was decreased and blood lactate, free fatty acid and ketone body concentrations were increased during the hangover period in the subjects who had been given only ethanol. These subjects also had a marked metabolic acidosis during hangover. Glucose and fructose significantly inhibited the metabolic alterations induced by ethanol. In this respect fructose was more effective than glucose. The results indicate that both fructose and glucose effectively inhibit the metabolic disturbances induced by ethanol but they do not affect the symptoms or signs of alcohol intoxication and hangover. The results support the view that hangover is not directly related to the metabolic effects of ethanol or to its metabolic products.     

Metabolic consequence of two-week fructose feeding in diabetic subjects

We studied the metabolic effects of 2-wk fructose feeding as the sweetener in the diet of seven non-insulin-dependent diabetic individuals. The data demonstrated reduced postprandial hyperglycemia to an oral glucose challenge after 14 days without a significant difference in insulin response. There was no change in the markedly blunted glucose response to a fructose challenge but a significantly lower insulin response (area under the 3-h curve) was observed after 14 days of fructose feeding. There was reduced postprandial hyperglycemia after 14 days of fructose feeding with test meals as compared with baseline, without significant differences in insulin response. We also found no significant difference in free fatty acids, cholesterol, high-density lipoprotein (HDL) cholesterol, pyruvate, lactate, or uric acid after fructose feedings. There was a 13% increase in triglyceride levels after 14 days in 5 subjects with initial fasting hypertriglyceridemia (greater than 150 mg/dl). Insulin receptor binding to isolated adipocytes did not change after 14 days of fructose feeding.     

Peritoneal transport characteristics with glycerol-based dialysate in peritoneal dialysis.

BACKGROUND: Glycerol is a low molecular weight solute (MW 92 D) that can be used as an osmotic agent in continuous ambulatory peritoneal dialysis (CAPD). Due to its low molecular weight, the osmotic gradient disappears rapidly. Despite the higher osmolality at the beginning of a dwell, ultrafiltration has been found to be lower for glycerol compared to glucose (MW 180 D) when equimolar concentrations are used. Previous studies have shown glycerol to be safe for long-term use, but some discrepancies have been reported in small solute transport and protein loss. OBJECTIVE: To assess permeability characteristics for a 1.4% glycerol dialysis solution compared to 1.36% glucose. DESIGN: Two standardized peritoneal permeability analyses (SPA), one using 1.4% glycerol and the other using 1.36% glucose, in random order, were performed within a span of 2 weeks in 10 stable CAPD patients. The length of the study dwell was 4 hours. Fluid kinetics and solute transport were calculated and signs of cell damage were compared for the two solutions. SETTING: Peritoneal dialysis unit in the Academic Medical Center, Amsterdam. RESULTS: Median values for the 1.4% glycerol SPA were as follows: net ultrafiltration 251 mL, which was higher than that for 1.36% glucose (12 mL, p < 0.01); transcapillary ultrafiltration rate 2.12 mL/min, which was higher than that for glucose (1.52 mL/min, p = 0.01); and effective lymphatic absorption rate 1.01 mL/min, which was not different from the glucose-based solution. Calculation of peritoneal reflection coefficients for glycerol and glucose showed lower values for glycerol compared to glucose (0.03 vs 0.04, calculated with both the convection and the diffusion models). A marked dip in dialysate-to-plasma ratio for sodium was seen in the 1.4% glycerol exchange, suggesting uncoupled water transport through water channels. Mass transfer area coefficients for urea, creatinine, and urate were similar for both solutions. Also, clearances of the macromolecules beta2-microglobulin, albumin, IgG, and alpha2-macroglobulin were not different for the two osmotic agents. The median absorption was higher for glycerol, 71% compared to 49% for glucose (p < 0.01), as could be expected from the lower molecular weight. The use of a 1.4% glycerol solution during a 4-hour dwell caused a small but significant median rise in plasma glycerol, from 0.22 mmol/L to 0.45 mmol/L (p = 0.02). Dialysate cancer antigen 125 and lactate dehydrogenase (LDH) concentrations during the dwell were not different for both solutions. CONCLUSIONS: These findings show that glycerol is an effective osmotic agent that can replace glucose in short dwells and show no acute mesothelial damage. The higher net ultrafiltration obtained with 1.4% glycerol can be explained by the higher initial net osmotic pressure gradient. This was seen especially in the first hour of the dwell. Thereafter, the osmotic gradient diminished as a result of absorption. The dip in dialysate-to-plasma ratio for sodium seen in the glycerol dwell can also be explained by this high initial osmotic pressure gradient, implying that the effect of glycerol as an osmotic agent is more dependent on intact water channels than is glucose.     

短期胰岛素强化治疗重症肺炎合并血糖异常临床研究

目的：探讨短期胰岛素强化治疗重症肺炎合并血糖异常的临床效果。方法将76例重症肺炎合并血糖异常患者按随机数字表法分为观察组和对照组,每组38例,均应用抗生素有效控制感染,观察组给予胰岛素强化治疗,对照组给予常规降糖治疗,观察5d。治疗前后检测血小板计数、C反应蛋白和空腹血糖水平的变化,比较两组有效率和并发症发生率。结果治疗后观察组血小板计数、C反应蛋白水平较治疗前显著升高,空腹血糖水平较治疗前显著下降（P＜0．05或0．01）,血小板计数显著高于对照组,C反应蛋白及空腹血糖水平显著低于对照组（ P＜0．05或0．01）。观察组总有效率（94．7％）显著高于对照组（78．9％）（χ2＝4．15,P＜0．05）;观察组并发症主要表现为低血糖,发生率（73．7％）显著高于对照组（47．4％）（χ2＝5．51,P＜0．05）。结论短期胰岛素强化治疗重症肺炎合并血糖异常患者能显著降低高炎症反应状态,有利于控制感染和控制血糖水平,提高临床疗效,但在治疗过程中应加强血糖监控,预防低血糖的发生。