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A Thorell

Publications and source records attributed to A Thorell.

At least 19 recordsLinked to original sources
PubMed2000

Exercise induces isoform-specific increase in 5'AMP-activated protein kinase activity in human skeletal muscle.

The 5'AMP-activated protein kinase (AMPK) is stimulated by contractile activity in rat skeletal muscle. AMPK has emerged as an important signaling intermediary in the regulation of cell metabolism being linked to exercise-induced changes in muscle glucose and fatty acid metabolism. In the present study, we determined the effects of exercise on isoform-specific AMPK activity (alpha1 and alpha2) in human skeletal muscle. Needle biopsies of vastus lateralis muscle were obtained from seven healthy subjects at rest, after 20 and 60 min of cycle ergometer exercise at 70% of VO(2)max, and 30 min following the 60 min exercise bout. In comparison to the resting state, AMPK alpha2 activity significantly increased at 20 and 60 min of exercise, and remained at a higher level with 30 min of recovery. AMPK alpha1 activity tended to slightly decrease with 20 min of exercise at 70%VO(2)max; however, the change was not statistically significant. AMPK alpha1 activities were at basal levels at 60 min of exercise and 30 min of recovery. On a separate day, the same subjects exercised for 20 min at 50% of VO(2)max. Exercise at this intensity did not change alpha2 activity, and similar to exercise at 70% of VO(2)max, there was no significant change in alpha1 activity. In conclusion, exercise at a higher intensity for only 20 min leads to increases in AMPK alpha2 activity but not alpha1 activity. These results suggest that the alpha2-containing AMPK complex, rather than alpha1, may be involved in the metabolic responses to exercise in human skeletal muscle.

Adenosine Triphosphate↗
PubMed2000

The hyperinsulinaemic-euglycaemic glucose clamp: reproducibility and metabolic effects of prolonged insulin infusion in healthy subjects.

To examine the reproducibility of the hyperinsulinaemic-euglycaemic clamp technique at mid-physiological hyperinsulinaemia, seven healthy subjects ¿age 50 (25, 59) years [median (range)], body mass index 23.1 (20.8, 25.5) kg.m(-2)¿ were investigated with three 2 h hyperinsulinaemic (60 micromol.l(-1))-euglycaemic (4.5 mmol.l(-1)) clamps performed 48 h and 14 days apart respectively. The third clamp was prolonged to 8 h in order to examine effects on glucose disposal during prolonged clamps. The glucose infusion rates (GIRs) during the three 2 h clamps were 7.41 (4.28, 10.96), 7.26 (5.38, 11. 02) and 6.63 (4.42, 10.3) mg.kg(-1).min(-1), with a median intra-individual coefficient of variation of 5.8 (2.6, 22) %. During the 8 h clamp a highly variable gradual increase in GIR was observed, reaching a plateau between 4 and 5 h at 32 (5, 101) % above the GIR between 1 and 2 h (P<0.05). This increase was correlated inversely with the GIR between 1 and 2 h (r=-0.82; P<0.05), and directly with age (r=0.86; P<0.05). Carbohydrate oxidation measured by indirect calorimetry was stable during the repeated 2 h clamps and the 8 h clamp. Endogenous glucose production measured by infusion of [6, 6-(2)H(2)]glucose was suppressed during the 8 h clamp. The 2 h hyperinsulinaemic-euglycaemic clamp is reproducible at a mid-physiological range of hyperinsulinaemia. If prolonged, it results in a delayed increase in non-oxidative glucose disposal, which is most pronounced in subjects with low insulin sensitivity. The findings underline the importance of selecting age-matched controls in studies of insulin resistance.

Adult↗
PubMed1999

Preoperative oral carbohydrates and postoperative insulin resistance.

UNLABELLED: Infusions of carbohydrates before surgery have been shown to reduce postoperative insulin resistance. Presently, we investigated the effects of a carbohydrate drink, given shortly before surgery, on postoperative insulin sensitivity. METHODS: Insulin sensitivity and glucose turnover ([6, 6,(2)H(2)]-D-glucose) were measured using hyper-insulinemic, normoglycemic clamps before and after elective surgery. Sixteen patients undergoing total hip replacement were randomly assigned to preoperative oral carbohydrate administration (CHO-H, n = 8) or the same amount of a placebo drink (placebo, n = 8) before surgery. Insulin sensitivity was measured before and immediately after surgery. Patients undergoing elective colorectal surgery were studied before surgery and 24 h postoperatively (CHO-C (n = 7), and fasted (n = 7), groups). The fasted group underwent surgery after an overnight fast. In both studies, the CHO groups received 800 ml of an isoosmolar carbohydrate rich beverage the evening before the operation (100g carbohydrates), as well as another 400 ml (50g carbohydrates) 2 h before the initiation of anesthesia. RESULTS: Immediately after surgery, insulin sensitivity was reduced 37% in the placebo group (P < 0.05 vs. preoperatively) while no significant change was found in the CHO-H group (-16%, p = NS). During clamps performed 24h postoperatively, insulin sensitivity and whole-body glucose disposal was reduced in both groups, but the reduction was greater compared to that in the CHO-C group (-49 +/- 6% vs. -26 +/- 8%, P>> 0.05 fasted vs. CHO-C). CONCLUSIONS: Patients given a carbohydrate drink shortly before elective surgery displayed less reduced insulin sensitivity after surgery as compared to patients undergoing surgery after an overnight fast.

Administration, Oral↗
PubMed1999

Value of diagnostic laparoscopy in fertile women with suspected appendicitis.

OBJECTIVE: To assess the value of diagnostic laparoscopy in women of child-bearing age with suspected appendicitis. DESIGN: Prospective, non-randomised study. SETTING: University hospital, Sweden. SUBJECTS: 94 women aged between 15 and 40 years with suspected appendicitis. INTERVENTION: Diagnostic laparoscopy. If necessary, the appendix was removed either laparoscopically or by open operation. The outcomes were compared with those during 1994, during which all appendicectomies were done through a laparotomy. MAIN OUTCOME MEASURES: Rates of unnecessary appendicectomy, operating time, and length of hospital stay. RESULTS: 77 had diagnostic laparoscopy, and 17 primary open appendicectomy. 73 appendixes were removed; 53 open and 20 laparoscopically. 12 appendicectomies (13%) were unnecessary compared with 27/80 (34%) during the year 1994. The duration of the open operation was significantly shorter (mean (SD) 35 (14) minutes) than the laparoscopic one (78 (18) minutes) (p<0.001), and there were no differences in duration of postoperative hospital stay. No patients developed complications. CONCLUSIONS: Diagnostic laparoscopy is safe and helpful in suspected cases of appendicitis and could substantially reduce the rate of unnecessary appendicectomies. However, the data suggest that laparoscopic appendicectomy offers no advantages over primary open appendicectomy in terms of postoperative course.

Adolescent↗
PubMed1999

Insulin resistance: a marker of surgical stress.

Elective surgery causes a marked, transient reduction in insulin sensitivity. The degree of the reduction is related to the magnitude of the operation. The type and duration of surgery performed, perioperative blood loss, and also the degree of postoperative insulin resistance have significant influences on the length of hospital stay. A novel approach to minimize insulin resistance after surgery is being presented and suggests that simply pretreating the elective surgical patient with sufficient amounts of carbohydrates instead of fasting can significantly reduce postoperative insulin resistance. It is not clear which mediators are the most important for the development of insulin resistance after surgery. Nevertheless, marked insulin resistance can develop after elective surgery without concomitant elevations in cortisol, catecholamines or glucagon. The main sites for insulin resistance seem to be extrahepatic tissues, probably skeletal muscle, where preliminary data suggest that the glucose transporting system is involved.

Animals↗
PubMed1999

Surgery-induced insulin resistance in human patients: relation to glucose transport and utilization.

To investigate the underlying molecular mechanisms for surgery-induced insulin resistance in skeletal muscle, six otherwise healthy patients undergoing total hip replacement were studied before, during, and after surgery. Patients were studied under basal conditions and during physiological hyperinsulinemia (60 microU/ml). Biopsies of vastus lateralis muscle were used to measure GLUT-4 translocation, glucose transport, and glycogen synthase activities. Surgery reduced insulin-stimulated glucose disposal (P < 0.05) without altering the insulin-stimulated increase in glucose oxidation or suppression of endogenous glucose production. Preoperatively, insulin infusion increased plasma membrane GLUT-4 in all six subjects (P < 0.05), whereas insulin-stimulated GLUT-4 translocation only occurred in three patients postoperatively (not significant). Moreover, nonoxidative glucose disposal rates and basal levels of glycogen synthase activities in muscle were reduced postoperatively (P < 0.05). These findings demonstrate that peripheral insulin resistance develops immediately postoperatively and that this condition might be associated with perturbations in insulin-stimulated GLUT-4 translocation as well as nonoxidative glucose disposal, presumably at the level of glycogen synthesis.

Arthroplasty, Replacement, Hip↗
PubMed1999

Exercise and insulin cause GLUT-4 translocation in human skeletal muscle.

Studies in rodents have established that GLUT-4 translocation is the major mechanism by which insulin and exercise increase glucose uptake in skeletal muscle. In contrast, much less is known about the translocation phenomenon in human skeletal muscle. In the current study, nine healthy volunteers were studied on two different days. On one day, biopsies of vastus lateralis muscle were taken before and after a 2-h euglycemic-hyperinsulinemic clamp (0.8 mU. kg(-1). min(-1)). On another day, subjects exercised for 60 min at 70% of maximal oxygen consumption (VO(2 max)), a biopsy was obtained, and the same clamp and biopsy procedure was performed as that during the previous experiment. Compared with insulin treatment alone, glucose infusion rates were significantly increased during the postexercise clamp for the periods 0-30 min, 30-60 min, and 60-90 min, but not during the last 30 min of the clamp. Plasma membrane GLUT-4 content was significantly increased in response to physiological hyperinsulinemia (32% above rest), exercise (35%), and the combination of exercise plus insulin (44%). Phosphorylation of Akt, a putative signaling intermediary for GLUT-4 translocation, was increased in response to insulin (640% above rest), exercise (280%), and exercise plus insulin (1,000%). These data demonstrate that two normal physiological conditions, moderate intensity exercise and physiological hyperinsulinemia approximately 56 microU/ml, cause GLUT-4 translocation and Akt phosphorylation in human skeletal muscle.

Adult↗
PubMed1998

Preoperative oral carbohydrate administration reduces postoperative insulin resistance.

UNLABELLED: Infusions of carbohydrates before surgery reduce postoperative insulin resistance. We in-vestigated the effects of a carbohydrate drink, given shortly before surgery, on postoperative metabolism. METHOD: Insulin sensitivity, glucose turnover ([6,6, 2H2]-D-glucose) and substrate utilization were measured using hyperinsulinemic normoglycemic clamps and indirect calorimetry in two matched groups of patients before and after elective colorectal surgery. The drink group (n = 7) received 800 ml of an isoosmolar carbohydrate rich beverage the evening before the operation (100 g carbohydrates), as well as another 400 ml (50 g carbohydrates) 2 h before the initiation of anesthesia. The fasted group (n = 7) was operated after an overnight fast. RESULTS: After surgery, energy expenditure increased in both groups. Endogenous glucose production was higher after surgery and the difference was significant during low insulin infusion rates in both groups (P < 0.05). The supressibility of endogenous glucose production by the two step insulin infusion was similar pre-and postoperatively in both groups. At the high insulin infusion rate postoperatively, whole body glucose disposal was more reduced in the fasted group (-49 +/- 6% vs -26 +/- 8%, P < 0.05 vs drink). Furthermore, during high insulin infusion rates, glucose oxidation decreased postoperatively only in the fasted group (P < 0. 05) and postoperative levels of fat oxidation were greater in the fasted group (P < 0.05 vs drink). Only minor postoperative changes in cortisol and glucagon were found and no differences were found between the treatment groups. CONCLUSIONS: Patients given a carbohydrate drink shortly before elective colorectal surgery displayed less reduced insulin sensitivity after surgery as compared to patients who were operated after an overnight fast.

Adolescent↗
PubMed1998

Extracellular-regulated protein kinase cascades are activated in response to injury in human skeletal muscle.

The mitogen-activated protein (MAP) kinase signaling pathways are believed to act as critical signal transducers between stress stimuli and transcriptional responses in mammalian cells. However, it is not known whether these signaling cascades also participate in the response to injury in human tissues. To determine whether injury to the vastus lateralis muscle activates MAP kinase signaling in human subjects, two needle biopsies or open muscle biopsies were taken from the same incision site 30-60 min apart. The muscle biopsy procedures resulted in striking increases in dual phosphorylation of the extracellular-regulated kinases (ERK1 and ERK2) and in activity of the downstream substrate, the p90 ribosomal S6 kinase. Raf-1 kinase and MAP kinase kinase, upstream activators of ERK, were also markedly stimulated in all subjects. In addition, c-Jun NH2-terminal kinase and p38 kinase, components of two parallel MAP kinase pathways, were activated following muscle injury. The stimulation of the three MAP kinase cascades was present only in the immediate vicinity of the injury, a finding consistent with a local rather than systemic activation of these signaling cascades in response to injury. These data demonstrate that muscle injury induces the stimulation of the three MAP kinase cascades in human skeletal muscle, suggesting a physiological relevance of these protein kinases in the immediate response to tissue injury and possibly in the initiation of wound healing.

Biopsy, Needle↗
PubMed1998

Perioperative insulin and glucose infusion maintains normal insulin sensitivity after surgery.

Elective surgery was performed after overnight fasting, a routine that may affect the metabolic response to surgery. We investigated the effects of insulin and glucose infusions before and during surgery on postoperative substrate utilization and insulin sensitivity. Seven patients were given insulin and glucose infusions 3 h before and during surgery (insulin group), and a control group of six patients underwent surgery after fasting overnight. Insulin sensitivity and glucose kinetics (D-[6,6-2H2]glucose) were measured before and immediately after surgery using a hyperinsulinemic, normoglycemic clamp. Glucose infusion rates and whole body glucose disposal decreased after surgery in the control group (-40 and -29%, respectively), whereas no significant change was found in the insulin group (+16 and +25%). Endogenous glucose production remained unchanged in both groups. Postoperative changes in cortisol, glucagon, fat oxidation, and free fatty acids were attenuated in the insulin group (vs. control). We conclude that perioperative insulin and glucose infusions minimize the endocrine stress response and normalize postoperative insulin sensitivity and substrate utilization.

Arthroplasty, Replacement, Hip↗
PubMed1998

Postoperative induction of insulin-like growth factor binding protein-3 proteolytic activity: relation to insulin and insulin sensitivity.

Increased serum insulin-like growth factor (IGF)-binding protein-3 (IGFBP-3) proteolytic activity (IGFBP-3-PA) has been demonstrated in a number of clinical states of insulin resistance, including severe illness, after surgery, and in noninsulin-dependent diabetes mellitus. In the present study we assessed the role of insulin sensitivity in expression of IGFBP-3-PA in serum. In 18 patients studied, a significant increase in IGFBP-3-PA (P < 0.005) was demonstrated after colo-rectal surgery. Eight patients receiving an oral glucose load before surgery demonstrated a significant greater relative increase in IGFBP-3-PA compared with 10 patients not receiving glucose (32.9 +/- 7.1% vs. 8.6 +/- 6.7%, respectively; P < 0.05). Both groups had reduced insulin sensitivity after surgery (-58 +/- 4%; P < 0.0001; n = 18), as determined by hyperinsulinemic, normoglycemic clamps; however, the group not receiving glucose displayed 18% less insulin sensitivity than the oral glucose load group (P < 0.05). Multiple regression analysis demonstrated that the relative changes in IGFBP-3-PA and C peptide levels were inversely correlated (P < 0.05), suggesting that increased IGFBP-3-PA, presumably increasing IGF bioavailability, may be associated with decreased insulin demands. Interestingly, insulin infusion during the 4-h hyperinsulinemic, normoglycemic clamp performed 24 h after surgery (post-op) resulted in a further increase in IGFBP-3-PA in both groups (P < 0.005), whereas no significant responses could be demonstrated during the pre-op clamp. The expression of increased IGFBP-3-PA was accompanied by conversion of endogenous intact 39/42-kDa IGFBP-3 into its 30-kDa fragmented form as determined by Western immunoblotting, and this conversion was virtually complete after the 4-h post-op clamp in patients displaying marked increases in IGFBP-3-PA. Characterization of the IGFBP-3-PA demonstrated that it was specific for IGFBP-3, as no degradation of IGFBP-1 and -2 was detected, and the use of various protease inhibitors demonstrated that serine proteases and possibly matrix metalloproteinases contribute to the increased IGFBP-3-PA level after surgery. We propose that IGF bioavailability may be increased by the induction of IGFBP-3-PA in insulin-resistant subjects, and that insulin regulates IGFBP-3-PA in this state.

Administration, Oral↗
PubMed1997

Site of insulin resistance after surgery: the contribution of hypocaloric nutrition and bed rest.

1. Insulin resistance after surgery has been shown to be related to several important derangements in protein and fat metabolism. However, mechanisms of impaired glucose tolerance after surgery remain ill-defined. 2. Insulin sensitivity and glucose kinetics (6,6(2)H2-glucose) were studied in seven patients before and after elective surgery (surgery group), by two step-hyperinsulinaemic (0.3 and 0.8 munits kg-1 min-1), normoglycaemic (4.5 mmol/l) clamps. Six healthy subjects were studied, using the same protocol, before and after a similar period of bed rest and hypocaloric nutrition (fast/bed rest group) to delineate the effects of surgery per se. 3. Basal endogenous glucose production and whole-body glucose disposal was higher after surgery (P < 0.001), whereas no change was found after fast/bed rest. During glucose clamps, the glucose infusion rates required to maintain normoglycaemia and whole-body glucose disposal decreased (P < 0.001) after surgery, while endogenous glucose production increased (P < 0.001). In the control subjects, levels of endogenous glucose production remained unchanged after fast/bed rest. In contrast, glucose infusion rates and whole-body glucose disposal during glucose clamps also decreased after fast/bed rest (P < 0.01). However, the relative decrease in both these parameters was greater after surgery compared with after fast/bed rest (P < 0.01). 4. After surgery, energy expenditure and fat oxidation increased (P < 0.001), whereas glucose oxidation decreased (P < 0.05). No significant change was found in glucose utilization postoperatively. After fast/bed rest, no change was found in energy expenditure. However, fat oxidation increased (P < 0.01), whereas glucose oxidation and glucose utilization decreased (P < 0.05). 5. In conclusion, impaired glucose tolerance develops after surgery as a result of decreased insulin-stimulated whole-body glucose disposal as well as increased endogenous glucose release. Despite the increase in endogenous glucose production, the reduction in endogenous glucose production with each elevation of insulin was unaffected by surgery. Perioperative bed rest and/or hypocaloric nutrition contribute to the decrease in insulin-stimulated whole-body glucose disposal in the post-operative state, whereas these factors have no effects on endogenous glucose production.

Adult↗
PubMed1997

Vitamin A concentration in the liver decreases with age in patients with cystic fibrosis.

BACKGROUND: Vitamin A deficiency is a common manifestation in cystic fibrosis (CF), but high levels of vitamin A in the liver have also been described. High levels of vitamin A in the liver are toxic, while normal levels might be protective against liver damage. In order to investigate whether liver damage in patients with CF is related to vitamin A content of the liver, vitamin A status was investigated in 15 patients with CF aged 8 to 34 years. METHODS: Liver biopsy was performed on clinical indication and the vitamin A concentration in the liver was determined as retinylpalmitate. Serum levels of retinol and retinol-binding protein were investigated on the morning of the biopsy. Eight patients had morphologic signs of cirrhosis. Eight patients had been on treatment with ursodeoxycholic acid for 1 to 3 years. All but three patients had been on vitamin A supplementation for years. RESULTS: Five patients had serum concentrations of retinol below the reference range and seven patients had decreased serum levels of retinol-binding protein. There was a strong correlation between serum levels of retinol and retinol-binding protein (rs = 0.90, p = 0.01), but no correlations with age, Shwachamn score, or genotype. Six of the patients had vitamin A concentrations in the liver < 40 micrograms/g wet weight, and the concentrations decreased significantly with age (rs = 0.77, p = 0.01), without correlation to clinical score or liver disease. There was no indication of hypervitaminosis, although younger patients had been or were being treated with vitamin A in fat-water emulsion. CONCLUSIONS: Our results indicate that the risk of vitamin a deficiency in cystic fibrosis increases with age. The data do not support the view that patients are at risk for hypervitaminosis by long-term supplementation with vitamin A. No correlation was found between the severity of liver disease and the vitamin A content in the liver.

Adolescent↗
PubMed1996

The effect of preoperative carbohydrate loading on hormonal changes, hepatic glycogen, and glucoregulatory enzymes during abdominal surgery.

The effect of preoperative glucose infusion on preoperative alterations in hepatic glycogen content, the activity of key hepatic glucoregulatory enzymes (fructose 1,6-diphosphatase [FDPase]), pyruvate kinase (PK), hormonal developments, and plasma levels of free fatty acids (FFA) were investigated in 16 patients undergoing open cholecystectomy. Patients were randomized to receive (group G) or not receive (group C) overnight glucose infusion (5 mg.kg-1.d-1) preoperatively. Infusion of glucose overnight resulted in preoperative elevations of insulin and c-peptide (P < 0.05) and lower plasma levels of FFA, while the same glucose levels were found in both groups, 4.6 mmol/L. During and after surgery, only minor changes in the plasma levels of insulin, c-peptide, catecholamines, glucagon, cortisol, growth hormone, and FFA were found, with minimal differences between groups. The hepatic glycogen content was 65% higher in group G and a significant reduction was confirmed only in this group of patients during surgery. The higher glycogen content was associated with a higher FDPase activity ratio (P < 0.05), which remained unchanged during surgery. In contrast, a significant (P < 0.05) increase in the activity of this enzyme was found in group C. The PK activity ratio did not differ between groups and remained unchanged during surgery. The finding of enhanced FDPase activity suggests that the indirect route (via gluconeogenesis) represents an important contributor to the increased glycogen formation during glucose infusion. Additionally, surgery in the overnight fasted patient induces enzymatic changes favoring gluconeogenesis. Lastly, preoperative high-dose glucose infusion has only minor effects on the endocrine response, plasma levels of FFA, and glycogen depletion during elective open cholecystectomy.

Adult↗
PubMed1996

Determination of protein synthesis in lymphocytes in vivo after surgery.

1. The stimulation and depression of peripheral blood lymphocytes has previously been studied in vitro, showing an immune depression postoperatively; however, it is difficult to interpret these in vitro findings. Therefore, an in vivo technique has been established for determination of the fractional protein synthesis rate, as an index of metabolic activity in human peripheral blood lymphocytes, by using a stable isotope technique. 2. The rate of protein synthesis was calculated from the increase in enrichment of L-[2H5]phenylalanine in protein of a mixed population of mononuclear leucocytes, isolated by density gradient, after an intravenous flooding dose of L-[2H5]phenylalanine. A linear time course of isotopic incorporation into the cells was demonstrated. 3. The fractional rate of protein synthesis of a mixed population of mononuclear leucocytes was studied in relation to surgical interventions and to potential modifiers of the response. The fractional synthesis rate increased 24 h after open and laparoscopic cholecystectomy (49 +/- 19% and 40 +/- 14% respectively, P < 0.02), irrespective of postoperative total parenteral nutrition or preoperative glucose infusion. In contrast to surgery, insulin did not stimulate protein synthesis in peripheral mononuclear leucocytes.

Adult↗
PubMed1996

The metabolic response to cholecystectomy: insulin resistance after open compared with laparoscopic operation.

OBJECTIVE: To study the changes in insulin sensitivity and plasma concentrations of interleukin-6 (IL-6) after open compared with laparoscopic cholecystectomy. DESIGN: Prospective open study. SETTING: University hospital, Sweden. SUBJECTS: 12 otherwise healthy patients undergoing either open (n = 6) or laparoscopic (n = 6) cholecystectomy. MAIN OUTCOME MEASURE: Relative insulin sensitivity (compared with preoperative) on the day after operation. Changes in IL-6 concentrations postoperatively. RESULTS: The mean (SEM) relative reduction in insulin sensitivity was significantly smaller after laparoscopic (18 (5)%) compared with the open operation, (58 (4)%) (p < 0.01). There was a significant increase in plasma concentrations of IL-6 postoperatively, but there was no difference between the groups. CONCLUSION: Insulin sensitivity is less affected 24 hours after laparoscopic than after open cholecystectomy, which in this study was not accompanied by a simultaneous difference in the IL-6 response. The small postoperative reduction of insulin sensitivity may be a contributing factor to the clinical benefit of improved wellbeing observed after laparoscopic surgery.

Adult↗
PubMed1995

Laparoscopic cholecystectomy does not prevent the postoperative protein catabolic response in muscle.

OBJECTIVE: The authors determined the effect of laparoscopic cholecystectomy on protein synthesis in skeletal muscle. In addition to a decrease in muscle protein synthesis, after open cholecystectomy, the authors previously demonstrated a decrease in insulin sensitivity. This study on patients undergoing laparoscopic and open surgery, therefore, included simultaneous measurements of protein synthesis and insulin sensitivity. SUMMARY BACKGROUND DATA: Laparoscopy has become a routine technique for several operations because of postoperative benefits that allow rapid recovery. However, its effect on postoperative protein catabolism has not been characterized. Conventional laparotomy induces a drop in muscle protein synthesis, whereas degradation is unaffected. METHODS: Patients were randomized to laparoscopic or open cholecystectomy, and the rate of protein synthesis in skeletal muscle was determined 24 hours postoperatively by the flooding technique using L-(2H5)phenylalanine, during a hyperinsulinemic normoglycemic clamp to assess insulin sensitivity. RESULTS: The protein synthesis rate decreased by 28% (1.77 +/- 0.11%/day vs. 1.26 +/- 0.08%/day, p < 0.01) in the laparoscopic group and by 20% (1.97 +/- 0.15%/day vs. 1.57 +/- 0.15%/day, p < 0.01) in the open cholecystectomy group. In contrast, the fall in insulin sensitivity after surgery was lower with laparoscopic (22 +/- 2%) compared with open surgery (49 +/- 5%). CONCLUSIONS: Laparoscopic cholecystectomy did not avoid a substantial decline in muscle protein synthesis, despite improved insulin sensitivity. The change in the two parameters occurred independently, indicating different mechanisms controlling insulin sensitivity and muscle protein synthesis.

Adult↗