References of "Letiexhe, Michel"
     in
Bookmark and Share    
Peer Reviewed
See detailImplications virales dans l'etiopathogenie du diabete de type 1: donnees actuelles.
Radermecker, Régis ULg; Scheen, André ULg; Letiexhe, Michel ULg et al

in Revue Médicale de Liège (1998), 53(10), 597-602

Type 1 diabetes mellitus results from autoimmune destruction of pancreatic beta cells. After having described genetic, immunological and metabolic factors, some researchers have hypothezised that ... [more ▼]

Type 1 diabetes mellitus results from autoimmune destruction of pancreatic beta cells. After having described genetic, immunological and metabolic factors, some researchers have hypothezised that environmental factors might trigger the autoimmune process. Based on epidemiological, anatomoclinical and animal studies, they suggest a role for virus infections. [less ▲]

Detailed reference viewed: 46 (2 ULg)
Peer Reviewed
See detailPharma clinics. Comment je traite ... un patient diabetique avec obesite severe.
Scheen, André ULg; Triches, K.; Luyckx, Françoise ULg et al

in Revue Médicale de Liège (1998), 53(7), 386-9

Obesity plays a crucial role in type 2 diabetes pathophysiology and a major weight loss markedly improves glycaemic control. The common failure of classical treatments leads to the use of more aggressive ... [more ▼]

Obesity plays a crucial role in type 2 diabetes pathophysiology and a major weight loss markedly improves glycaemic control. The common failure of classical treatments leads to the use of more aggressive weight-reduction approaches, such as very-low-calorie diets (VLCDs), anti-obesity drugs or even bariatric surgery. VLCDs are very successful in the short-term but rather disappointing in the long-term. Anti-obesity compounds only induce a modest mean weight reduction, even if some patients appear to be better responders. Interestingly, serotoninergic agents increase insulin sensitivity and glycaemic control, independently of weight loss. Bariatric surgery provides the most impressive results. In well-selected subjects, gastroplasty (either vertical ring gastroplasty or adjustable silicone gastric banding) generally induces a considerable weight loss which results in a remarkable and sustained glycaemic control improvement and allows the reduction, or even the suppression, of any antidiabetic treatment. This ultimate solution should not be neglected after failure of medical approaches, provided that the indication is correct, the surgical procedure is performed in a specialized centre and the followup is well organized by a multidisciplinary team. [less ▲]

Detailed reference viewed: 11 (0 ULg)
Peer Reviewed
See detailA propos de quelques utilisations non conventionnelles de la metformine
SCHEEN, André ULg; PAQUOT, Nicolas ULg; LETIEXHE, Michel ULg et al

in Médecine et Hygiène (1997), 55

Detailed reference viewed: 13 (1 ULg)
Peer Reviewed
See detailPlasma leptin levels, insulin secretion, clearance and action on glucose metabolism in anorexia nervosa.
Letiexhe, Michel ULg; Scheen, André ULg; Lefebvre, Pierre ULg

in Eating and Weight Disorders [=EWD] (1997), 2(2), 79-86

From a metabolic point of view, anorexia nervosa may be viewed as a mirror image of obesity. We compared insulin secretion, clearance and action on glucose metabolism during an intravenous glucose ... [more ▼]

From a metabolic point of view, anorexia nervosa may be viewed as a mirror image of obesity. We compared insulin secretion, clearance and action on glucose metabolism during an intravenous glucose tolerance test in nine women with anorexia nervosa and in nine age-matched normal-weight controls. Insulin secretion (ISR) was derived by deconvolution of plasma C-peptide levels, insulin clearance (MCR(I)) was obtained by dividing the area under the curve (AUC(0-180 min)) of ISR by the corresponding AUC of plasma insulin levels, insulin sensitivity (S(I)) and glucose effectiveness index (S(G)) were calculated by Bergman's minimal model. The anorectic women had markedly lower BMI values (13.7+/-0.6 vs 23.2+/-0.8 kg/m2, p<0.0001) and serum basal leptin levels (2.8+/-0.6 vs 8.9+/-1.8 ng/mL, p=0.005) than control women. The anorectic women exhibited clear-cut lower fasting and post-glucose plasma insulin levels but similar corresponding plasma C-peptide concentrations when compared to controls. Consequently, ISR was similar in both groups while MCR(I) was significantly increased in anorexia nervosa (MCR(I): 3320+/-881 vs 822+/-79 mL x min(-1) x m(-2), p<0.02). The index S(I) tended to be higher in anorectic women than in normal-weight subjects, but without reaching the level of statistical significance because of a high between-subject variability (20.2+/-5.7 vs 12.5+/-2.2 10(-5) x min(-1)/pmol x L(-1), NS). The index S(G) was similar in both groups (0.022+/-0.004 vs 0.018+/-0.002 min(-1), NS). In conclusion, low plasma insulin levels observed in women with anorexia nervosa result from high MCR(I) rather than from depressed insulin secretion. Insulin sensitivity is not systematically increased and glucose effectiveness is unchanged in anorectic women when compared to normal-weight controls. [less ▲]

Detailed reference viewed: 46 (0 ULg)
Peer Reviewed
See detailComment explorer la sensibilite a l'insuline chez l'homme?
Scheen, André ULg; Paquot, Nicolas ULg; Letiexhe, Michel ULg et al

in Annales d'Endocrinologie (1995), 56(5), 523-30

The two most widely used methods for studying insulin sensitivity in man are the euglycaemic hyperinsulinaemic clamp and the intravenous glucose tolerance test with minimal model assessment. The glucose ... [more ▼]

The two most widely used methods for studying insulin sensitivity in man are the euglycaemic hyperinsulinaemic clamp and the intravenous glucose tolerance test with minimal model assessment. The glucose clamp is the reference method, well validated and easy to interpret, which allows various extensions to the basic experimental procedure in order to obtain more valuable information on the specific effects of insulin on the various aspects of glucose metabolism. However, it is time-consuming and labour-intensive. In contrast, the intravenous glucose tolerance test is easier to perform, but its interpretation is much more difficult and requires a modeling approach called the "minimal model". If the intravenous glucose tolerance test probably represents a good screening test, mainly on a population basis, the glucose clamp still remains the gold standard method to study insulin sensitivity in man. [less ▲]

Detailed reference viewed: 57 (0 ULg)
Peer Reviewed
See detailGlucose metabolism in obese subjects: lessons from OGTT, IVGTT and clamp studies.
Scheen, André ULg; Paquot, Nicolas ULg; Letiexhe, Michel ULg et al

in International Journal of Obesity & Related Metabolic Disorders (1995), 19 Suppl 3

Impaired glucose tolerance and overt diabetes are more frequent in presence than in absence of obesity. In obese subjects, glucose tolerance can be maintained within the normal range by compensating for ... [more ▼]

Impaired glucose tolerance and overt diabetes are more frequent in presence than in absence of obesity. In obese subjects, glucose tolerance can be maintained within the normal range by compensating for insulin resistance by peripheral hyperinsulinism, the latter resulting from both increased insulin secretion and reduced insulin clearance. Impaired glucose tolerance is observed when insulin resistance is associated to impaired first-phase insulin response, which results in a significant increase in plasma glucose levels and a late insulin hyperresponsiveness. Both hyperinsulinaemia and hyperglycaemia are then able to overcome peripheral insulin resistance and impaired glucose disposal. When a more marked defect in insulin secretion is present, hyperglycaemia progresses, probably due to an additional participation of impaired suppression of hepatic glucose output. Overt diabetes then occurs with persistent post-absorptive hyperglycaemia. All these abnormalities can be reversed after a marked weight loss and recovery of ideal body weight, arguing for acquired rather than inherited metabolic defects in presence of morbid obesity. If a sufficient weight reduction can not be obtained, pharmacological approaches may be considered to improve insulin resistance of obese subjects, especially those with impaired glucose tolerance or overt diabetes. [less ▲]

Detailed reference viewed: 38 (2 ULg)
Peer Reviewed
See detailPostgastroplasty recovery of ideal body weight normalizes glucose and insulin metabolism in obese women.
Letiexhe, Michel ULg; Scheen, André ULg; Gerard, Pascale ULg et al

in Journal of Clinical Endocrinology and Metabolism (1995), 80(2), 364-9

To study the metabolic effects of normalizing body weight, a frequently sampled iv glucose tolerance test (0.3 g/kg) was performed before [body mass index (BMI), 37.7 +/- 0.5 kg/m2] and 14 +/- 2 months ... [more ▼]

To study the metabolic effects of normalizing body weight, a frequently sampled iv glucose tolerance test (0.3 g/kg) was performed before [body mass index (BMI), 37.7 +/- 0.5 kg/m2] and 14 +/- 2 months after successful gastroplasty (BMI, 23.7 +/- 0.6 kg/m2) in eight obese women and, for comparison, in eight age- and weight-matched nonobese control women (BMI, 23.6 +/- 0.7 kg/m2). All subjects had normal oral glucose tolerance. The insulin secretion rate (ISR) was derived by deconvolution of plasma C-peptide levels and the insulin MCR (MCRI) by dividing the 0-180 min area under the curve (AUC) of ISR by that of plasma insulin levels (IRI). The insulin sensitivity index (SI) and the glucose effectiveness index (SG) were calculated using Bergman's minimal model. Before gastroplasty, obese subjects showed higher AUC-IRI (P < 0.001) and AUC-ISR (P < 0.02), lower MCRI (P < 0.005) and SI (P < 0.002), but similar SG values, compared to nonobese controls. After gastroplasty, the AUC-IRI dramatically decreased, due to both a reduction of AUC-ISR (from 58,252 +/- 8,437 to 36,675 +/- 4,274 pmol; P < 0.05) and an increase in MCRI (from 658 +/- 117 to 1,299 +/- 127 mL/min.m-2; P < 0.02). SI significantly rose from 4.74 +/- 0.74 to 9.15 +/- 0.96 10(-5) min-1/pmol.L (P < 0.01), whereas SG remained unchanged. All of these parameters became similar to those in nonobese controls (respectively, 32,522 +/- 3,458, 1,180 +/- 101, and 8.48 +/- 1.25; all P = NS). In conclusion, after gastroplasty-induced normalization of body weight, postobese women recover normal insulin secretion, clearance, and action on glucose metabolism. [less ▲]

Detailed reference viewed: 13 (1 ULg)
Peer Reviewed
See detailShort administration of metformin improves insulin sensitivity in android obese subjects with impaired glucose tolerance.
Scheen, André ULg; Letiexhe, Michel ULg; Lefebvre, Pierre ULg

in Diabetic Medicine : A Journal of the British Diabetic Association (1995), 12(11), 985-9

In a double-blind, randomized, cross-over study, the metabolic effects of a short treatment with metformin (2 x 850 mg day-1 for 2 days and 850 mg 1 h before evaluation) were compared to those of placebo ... [more ▼]

In a double-blind, randomized, cross-over study, the metabolic effects of a short treatment with metformin (2 x 850 mg day-1 for 2 days and 850 mg 1 h before evaluation) were compared to those of placebo in 15 obese subjects (BMI: 33.2 +/- 0.9 kg m-2), with abdominal distribution of adipose tissue and impaired glucose tolerance. An intravenous glucose tolerance test (0.3 g glucose kg-1) was performed after each period of treatment. Areas under the curve (AUC0-180 min) were calculated for plasma glucose, insulin, and C-peptide levels. Glucose tolerance was estimated by the coefficient of glucose assimilation (KG). Insulin sensitivity (SI) and glucose effectiveness (SG) indices were calculated using Bergman's minimal model. Insulin secretion rate (ISR) was determined by deconvolution of plasma C-peptide levels and insulin metabolic clearance rate (MCR) was estimated by dividing AUC 1SR by AUC insulin. Fasting plasma insulin levels were reduced after metformin (89.3 +/- 15.9 vs 112.4 +/- 24.3 pmol l-1; p = 0.04). AUC glucose, KG and SG were similar in both tests. However, AUC insulin was reduced (39.7 +/- 6.5 vs 51.8 +/- 10.4 nmol min l-1; p = 0.02), while SI (6.98 +/- 1.14 vs 4.61 +/- 0.42 10(-5) min-1 pmol-1 l; p = 0.03) and insulin MCR (715 +/- 116 vs 617 +/- 94 ml min-1 m-2; p = 0.03) were increased after metformin. The demonstration that metformin rapidly improves insulin sensitivity should encourage further research to evaluate the long-term effects of metformin in android obese subjects with impaired oral glucose tolerance. [less ▲]

Detailed reference viewed: 14 (1 ULg)
Peer Reviewed
See detailMeasurement of insulin sensitivity by the minimal model method using a simplified intravenous glucose tolerance test: validity and reproducibility.
Duysinx, Bernard ULg; Scheen, André ULg; Gerard, Pascale ULg et al

in Diabète & Métabolisme (1994), 20(4), 425-32

This study aimed at testing whether 12 rather than 26 plasma glucose and insulin determinations can be used to calculate the indices of insulin sensitivity and of glucose effectiveness using Bergman's ... [more ▼]

This study aimed at testing whether 12 rather than 26 plasma glucose and insulin determinations can be used to calculate the indices of insulin sensitivity and of glucose effectiveness using Bergman's minimal model during a simple intravenous glucose tolerance test performed without tolbutamide injection. Two intravenous glucose tolerance tests (separated by 1 week) were performed in 7 lean normal subjects and a single test was performed in 9 severely obese non-diabetic subjects. Intra-subject reproducibility of insulin sensitivity was not significantly different when 26 or 12 time-points were analyzed (CV = 16.8 +/- 3.4 versus 18.9 +/- 3.8% respectively). Compared with the insulin sensitivity of the lean subjects, that of obese subjects was significantly (P < 0.001) and similarly reduced when using 12 (2.14 +/- 0.34 versus 7.97 +/- 1.29 10(-4)min-1/mU.1-1) rather than 26 determinations (2.13 +/- 0.42 versus 6.95 +/- 1.12 10(-4) min-1/mU.1-1) respectively. Glucose effectiveness was less reproducible than insulin sensitivity and was slightly diminished by the reduction of blood samples (relative error: -9.7 +/- 4.4%; P < 0.05). Finally, glucose effectiveness tended to be slightly lower in the morbidly obese subjects than in the lean controls with both modes of calculation. In conclusion, in non-diabetic subjects, the insulin sensitivity index can be accurately measured during a simple intravenous glucose tolerance test, without tolbutamide injection and with only 12 blood samples. The possibility of performing a simplified test should contribute to increase the use of the minimal model method for estimating insulin sensitivity in clinical practice. [less ▲]

Detailed reference viewed: 29 (2 ULg)
Peer Reviewed
See detailInsulin secretion, clearance and action before and after gastroplasty in severely obese subjects.
Letiexhe, Michel ULg; Scheen, André ULg; Gerard, Pascale ULg et al

in International Journal of Obesity & Related Metabolic Disorders (1994), 18(5), 295-300

This study investigated the effects of a drastic weight reduction on insulin secretion rate (ISR), insulin metabolic clearance rate (MCRI) and insulin sensitivity (SI) in severely obese subjects. A ... [more ▼]

This study investigated the effects of a drastic weight reduction on insulin secretion rate (ISR), insulin metabolic clearance rate (MCRI) and insulin sensitivity (SI) in severely obese subjects. A frequently sampled intravenous glucose tolerance test (FSIVGTT, 0.3 g/kg) was performed before and 8 +/- 1 months after a vertical ring gastroplasty in 12 overnight-fasted obese non-diabetic subjects; the results were compared to those obtained in 12 lean controls matched for age and sex. ISR was derived by deconvolution of plasma C-peptide levels; MCRI was obtained by dividing the area under the curve (AUC180 min) of ISR by the corresponding AUC of plasma insulin levels (IRI); the SI and the glucose effectiveness index (SG) were calculated by Bergman's minimal model. Before gastroplasty, obese subjects showed significantly higher ISR (P < 0.02), lower MCRI (P < 0.001), lower SI (P < 0.001) but similar SG when compared to lean controls. After gastroplasty (reduction of body weight from 104.8 +/- 3.8 to 73.4 +/- 3.6 kg and of BMI from 37.9 +/- 0.8 to 26.5 +/- 0.9 kg/m2; P < 0.001), ISR only decreased from 53,125 +/- 7968 to 42,302 +/- 3716 pmol/180 min (not significant) while AUC-IRI dramatically fell from 53,626 +/- 6378 to 21,111 +/- 2584 pmol.min/l; P < 0.001); consequently, MCRI markedly increased from 526 +/- 96 to 1257 +/- 150 ml/min/m2; P < 0.01). SI significantly rose from 3.12 +/- 0.45 to 7.10 +/- 1.20 x 10(-4) l/mU/min (P < 0.005) while SG remained unchanged.(ABSTRACT TRUNCATED AT 250 WORDS) [less ▲]

Detailed reference viewed: 62 (2 ULg)
Peer Reviewed
See detailEffects of moderate versus marked weight loss on insulin sensitivity and androgenic markers in obese women
LETIEXHE, Michel ULg; SCHEEN, André ULg; PAQUOT, Nicolas ULg et al

in International Journal of Obesity (1993), 17(suppl 2), 96

Detailed reference viewed: 22 (2 ULg)
See detailEffects of moderate vs marked weight loss on insulin sensitivity and androgenic markers in obese women
LETIEXHE, Michel ULg; SCHEEN, André ULg; PAQUOT, Nicolas ULg et al

in Ditschuneit, H.; Gries, F. A.; Hauner, H. (Eds.) et al Obesity in Europe (1993)

Detailed reference viewed: 17 (0 ULg)
Peer Reviewed
See detailInsulin secretion, clearance, and action on glucose metabolism in cirrhotic patients.
Letiexhe, Michel ULg; Scheen, André ULg; Gerard, Pascale ULg et al

in Journal of Clinical Endocrinology and Metabolism (1993), 77(5), 1263-8

To study the mechanisms of glucose intolerance and hyperinsulinism in liver cirrhosis, we compared the plasma glucose, insulin, and C-peptide levels during a frequently sampled i.v. glucose tolerance test ... [more ▼]

To study the mechanisms of glucose intolerance and hyperinsulinism in liver cirrhosis, we compared the plasma glucose, insulin, and C-peptide levels during a frequently sampled i.v. glucose tolerance test (0.3 g glucose/kg BW) in nine compensated cirrhotic patients and nine healthy volunteers well matched for age, sex, and body weight. The insulin secretion rate was derived by the deconvolution of plasma C-peptide levels, insulin sensitivity was calculated using Bergman's minimal model method, and insulin clearance was estimated by dividing the 0-180 min area under the curve of insulin secretion rate by that of peripheral plasma insulin levels. The cirrhotic patients were characterized during the frequently sampled i.v. glucose tolerance test by a 60% greater insulin secretion rate (P < 0.05), a markedly reduced insulin sensitivity index (SI; 2.82 +/- 0.75 vs. 5.86 +/- 0.68 x 10(-4) min/mU.L; P < 0.01) and a 40% reduced insulin clearance (725 +/- 169 vs. 1165 +/- 99 mL/min.m-2; P < 0.05). The reduction of insulin clearance was significantly correlated with the amplitude of the portosystemic shunt, measured using an isotopic method (r = 0.75; P < 0.02). In conclusion, cirrhosis is characterized by an important peripheral hyperinsulinism, resulting from both a higher insulin secretion rate and a reduced insulin hepatic clearance; the severe insulin resistance explains the glucose metabolism alterations. [less ▲]

Detailed reference viewed: 31 (1 ULg)
Peer Reviewed
See detailLa péricardite tuberculeuse: intérêt du dosage de l'activité de l'adénosine déaminase
Letiexhe, Michel ULg; Pierard, Luc ULg; Kulbertus, Henri ULg

in Revue Médicale de Liège (1992), 47(10), 502-9

Detailed reference viewed: 57 (3 ULg)