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Biomedical subjects

G Slama

Publications and source records attributed to G Slama.

At least 55 records · Page 3Linked to original sources
PubMed2000

[Considerations on delocalized HbA1c assays].

Availability and knowledge of HbA(1c) value during consultation is an important feature for diabetologists, that permits a better adaptation of therapy and a better motivation of patients. This expectation explains the request for delocalized assays of HbA(1c), even though life prognosis is not affected, like in the other cases of point of care testing. One of the most frequent solutions is the use of immunological delocalized HbA(1c) assays. Technically, these methods have to meet the same criteria as those used in laboratories. They have to be standardized, and controlled according to the "Guide de Bonne Exécution des Analyses de Biologie Médicale" (GBEA) rules. Solutions chosen for delocalization must respect specific skills of clinicians and biologists and cope with cost limitations. This paper reviews rationales for delocalized HbA(1c) assays, steps of their implementation, and their use in practical routine, with a special emphasis given on the necessary complementarity between clinicians and biologists.

Biomarkers↗
PubMed1999

Grid photocoagulation for focal diabetic macular edema with focal leaks and hard exsudates involving the peri-foveolar area.

This study was conducted to determine whether indirect grid laser therapy is effective in reducing focal diabetic macular edema characterised by focal leaks and hard exsudates involving the para-foveal area (less than 300 microns from the center of the fovea). Since focal coagulation of microaneurysms in such a critical location can be deleterious, indirect grid pattern laser treatment may be used in such cases.

Adult↗
PubMed1999

Varying the protein source in mixed meal modifies glucose, insulin and glucagon kinetics in healthy men, has weak effects on subjective satiety and fails to affect food intake.

OBJECTIVE: To evaluate the influence of three dietary protein types (casein, gelatin, soy protein) on satiety and food intake, at two levels of loading (total energy of test meals: 3.6 or 1.8 MJ). DESIGN: The study employed a repeated measures design. Test meals were controlled for energy, macronutrients, fiber and palatability, and contained about 23% energy as protein (of which about 65% was experimentally manipulated). Postprandial subjective satiety and hunger, plasma glucose, insulin and glucagon were assessed for 8 h, and energy and macronutrient intakes were monitored for 24 h. SUBJECTS: Nine healthy normal-weight men. RESULTS: No effect of the type of protein on 24 h energy and macronutrient intakes was observed despite a significant effect of protein source on the kinetics of peripheral metabolic responses (but only after 3.6 MJ lunches), and inconsistent effects on subjective hunger and satiety responses A casein-enriched lunch delayed glucose and insulin responses for 1.5 h, compared with soy protein, probably due to a lag in gastric emptying. CONCLUSION: Varying the protein source in a mixed meal modifies glucose, insulin and glucagon kinetics in healthy men, but these variations in satiety-implicated factors have inconsistent effects on subjective satiety and fail to affect food intake. SPONSORSHIP: Eridania Béghin-Say, Vilvoorde, Belgium and Association Nationale de la Recherche Technique, France (Convention CIFRE no 537/94).

Adult↗
PubMed1999

Euglycemic hyperinsulinemic clamp to assess posthepatic glucose appearance after carbohydrate loading. 1. Validation in pigs.

BACKGROUND: Precise knowledge of the rate of glucose absorption after meal feeding requires invasive methods in humans. OBJECTIVE: This study aimed to validate in an animal model a technique combining the euglycemic hyperinsulinemic clamp and oral carbohydrate loading (OC-Clamp) as a noninvasive procedure to quantify the posthepatic appearance of glucose after oral carbohydrate loading. DESIGN: Twenty-one pigs were fitted with arterial, jugular, portal, and duodenal catheters and a portal blood flow probe. At glucose clamp steady state, duodenal glucose (0.9 g/kg; DG-Clamp) and oral carbohydrate (140 g corn or mung bean starch as part of a mixed meal; OC-Clamp) were administered while the glucose infusion was progressively reduced to compensate for the incremental posthepatic appearance of glucose. [3-3H]glucose was used to assess the glucose turnover rate. RESULTS: Hepatic glucose production was totally suppressed by insulin infusion, and the whole-body glucose turnover rate remained stable during glucose absorption. The incremental portal appearance of glucose after the DG load was not altered by hyperinsulinemia, and the cumulative posthepatic appearance of glucose was 63 +/- 3% (x +/- SEM) of the DG load. The net hepatic portal appearance of glucose remained constant during absorption (34 +/- 3% of the load). After the OC load, the respective portal appearance rates of glucose were significantly different between carbohydrate sources; however, the rates paralleled those of the posthepatic appearance of glucose. Again, net hepatic glucose uptake expressed as portal appearance was similar for both carbohydrates. CONCLUSIONS: The results validate the OC-Clamp method to monitor the posthepatic appearance of glucose after carbohydrate ingestion and to discriminate between different carbohydrate sources. The results suggest that the technique be used in humans.

Analysis of Variance↗
PubMed1999

Euglycemic hyperinsulinemic clamp to assess posthepatic glucose appearance after carbohydrate loading. 2. Evaluation of corn and mung bean starches in healthy men.

BACKGROUND: The rate of absorption of glucose from carbohydrates is important in several aspects of health. We recently validated a noninvasive technique in pigs, euglycemic hyperinsulinemic clamp plus oral carbohydrate loading (OC-Clamp), to quantify the rate of net posthepatic appearance of glucose after ingestion of carbohydrates. OBJECTIVE: The OC-Clamp procedure was performed in 8 healthy men to compare the net posthepatic appearance of glucose after ingestion of 1 of 3 carbohydrates. DESIGN: Human volunteers underwent the OC-Clamp procedure at an insulin infusion rate of 1.5 mU x kg(-1) x min(-1) (n = 5). The oral carbohydrate load (1 g/kg) consisted of glucose, cornstarch, or mung bean starch. During the OC-Clamp procedure, the glucose infusion rate decreased during absorption to maintain plasma glucose steady state and the decrease reflected the net posthepatic appearance of glucose. In addition, carbohydrates were loaded without insulin infusion (n = 6) and glycemic indexes were calculated (with glucose as the reference). RESULTS: The mean (+/-SEM) glycemic index of cornstarch was higher (95 +/- 18) than that of mung bean starch (51 +/- 13). In the OC-Clamp experiments, the posthepatic appearance of glucose and cornstarch did not differ significantly and represented 79.4 +/- 5.0% and 72.6 +/- 4.0%, respectively, of the load after complete absorption (within 3 h). In contrast, the net posthepatic appearance of glucose from mung bean starch was significantly lower (35.6 +/- 4.6% of the load, P < 0.001) than that from glucose and cornstarch, even 4.5 h postprandially. CONCLUSIONS: The OC-Clamp technique allows a continuous assessment of net posthepatic appearance of glucose after ingestion of carbohydrates and significant discrimination between corn and mung bean starches.

Analysis of Variance↗
PubMed1999

HBA1c: clinical and biological agreement for standardization of assay methods. Report by the experts of ALFEDIAM (Association de Langue Française pour lEtude du Diabète et des Maladies Métabolique) and SFBC (Société Française de Biologie Clinique).

Glycohaemoglobin, and particularly haemoglobin A1c(HbA1c), assays have been used for many years to retrospectively evaluate the glycaemic control of diabetic patients. Cut-off values have been established for deciding treatment modifications. The techniques used in the laboratories however exhibit varying quality, and all of them are not yet standardized. The consequence is an under-utilization of this test, especially in non-hospital practice. In this context, working groups of Société Française de Biologie Clinique (SFBC), Association de Langue Française pour l'Etude du Diabète et des Maladies Métaboliques (ALFEDIAM) and Société Française d'Endocrinologie (SFE) have met together, in order to analyze the national status, and to propose practical recommendations for implementing a standardization process on the basis of international experiences. It is recommended to exclusively express results as HbA1c percentage, using methods standardized and certified by comparison to reference methods such as those using Diabetes Control and Complications Trial (DCCT) values. Simultaneously, contacts have been established with manufacturers, and the realisation of periodic quality control surveys was encouraged.

Clinical Laboratory Techniques↗
PubMed1999

[Possible consequences on the follow up of type 2 diabetic patients of a recent modification of a glycosylated hemoglobin assay].

Glycated hemoglobin assay is considered as the gold standard for the follow-up of diabetic patients, and the assay must now be calibrated on the results of the method used in the DCCT study. It is considered as appropriate to intensify the therapy of type 2 diabetic patients when two consecutive values higher than 8% are observed. We present herein a case report illustrating the possible consequences on the follow up of type 2 diabetic patients of a recent significant modification, not reported elsewhere, aimed to eliminate a bias vs the DCCT method of a system, DCA 2000, largely used to determine HbA1c level in diabetic patients: before this modification, the DCA 2000 method underestimated the glycated hemoglobin level by 0.5% for a 8% value. Such is no more the case.

Adult↗
PubMed1998

Uncommon early-onset neuropathy in diabetic patients.

An acute neuropathy rarely occurs early in the course of diabetes mellitus. Five cases are described of adult patients who developed a peripheral neuropathy at the time or shortly after the onset or discovery of diabetes mellitus. Patient 1, an 80-year-old woman who developed a subacute tetraparesis with proximal and distal muscle weakness with normal cranial nerves, proved to have insulin-requiring diabetes mellitus. In the other patients, all men aged 23-34 years, symptomatic neuropathy occurred simultaneously (patient 2) or 1-6 months after the onset of insulin-dependent diabetes mellitus (IDDM) (patients 3-5). Patients 2 and 3 developed a symptomatic multifocal neuropathy; patients 4 and 5, a painful distal symmetrical sensory polyneuropathy (DSSP) shortly after beginning treatment with insulin. Nerve biopsy showed active axonal lesions in patients 2 and 5 and mixed axonal and demyelinating lesions in the others, with severe axon loss in patients 4 and 5. Vasculitic lesions were found in patient 2, who improved without additional treatment. Neurological examination remained unchanged after 2 years in patients 3-5. Although a coincidence cannot be excluded for patients 1-3, whose neuropathy was not of the pattern commonly found in diabetes, it is suggested that acute disequilibrium in the diabetic status may facilitate the occurrence of a variety of neuropathies. Alternatively, the autoimmune process which led to IDDM may also trigger an autoimmune neuropathy with vasculitis (patient 2) or demyelinative nerve lesions. Only the distal symmetrical sensory polyneuropathy with severe axonal lesions observed in patients 4 and 5 seems directly related to diabetes mellitus. In spite of their occurrence shortly after beginning insulin therapy, the role of treatment with insulin in the onset is uncertain.

Acute Disease↗
PubMed1998

French cross-cultural adaptation of the Health Utilities Indexes Mark 2 (HUI2) and 3 (HUI3) classification systems. Clinical and Economic Working Groups.

The McMaster Health Utilities Indexes Mark 2 (HUI2) and 3 (HUI3) are multiattribute health classification systems, for which multiattribute preference functions have been developed in Canada. They provide a comprehensive instrument for use in economic evaluations and population health survey studies. This paper reports on the first results on the adaptation of the HUI2 and HUI3 systems cross-culturally and the assessment of the validity and reliability of the French self-report questionnaire in different patient populations. The cross-cultural adaptation included translation, backtranslations, an expert consensus meeting and pre-test with a few patients and healthy subjects in order to produce a conceptually equivalent French version of the 15 question self-report questionnaire and the HUI2 and HUI3 classification systems. Different groups of patients attending specialized clinics (n = 709) completed the questionnaire and another generic questionnaire (the Sickness Impact Profile (SIP)) for validity assessment. Physicians and patients were also asked for a global subjective assessment of the patient's health status. The French questionnaire was well received by the patients. The criterion and convergent validities of both classification systems (correlations with the patients' and physicians' assessments and with the responses to the SIP questionnaire) were satisfactory. The internal consistency was acceptable too (Cronbach's alpha = 0.81), as was the 3 day test-retest reproducibility. These first results authorize careful use of the 15 question self-report questionnaire in French. An assessment of the multiattribute preference function for the HUI3 system in France will be the study's next objective.

Adolescent↗
PubMed1998

Reducing ice cream energy density does not condition decreased acceptance or engender compensation following repeated exposure.

OBJECTIVES: The preferences for high-fat foods are believed to be based on their sensory attributes and energy density; however less is known about how such preferences might be weakened, other than in response to deterioration in flavor or textural quality. The aim of the present study was to see whether acceptability of reduced fat/energy foods would wane as the original post-ingestive nutritional benefits are reduced when palatability remains essentially constant. DESIGN: Repeated measures, within-subjects design conducted in two counterbalanced three week trials. SETTING/SUBJECTS: Sixteen normal-weight males (mean age 25.8 +/- 1.2 y) came to our laboratory at the Hôpital Hotel Dieu in Paris to eat an afternoon snack on 13 consecutive days (excluding weekends). INTERVENTION/OUTCOME MEASURES: Intake was recorded following repeated exposure to two flavors of standard (10% fat as a percentage of total solids weight), and low (3%) fat ice cream. One group received standard vanilla or low-fat strawberry ice cream on alternate days for two consecutive weeks; these flavor associations were reversed for a second group. The two flavors were rated as equipalatable at the beginning of the experiment at all energy levels. RESULTS: Subjects consumed the same quantity of ice cream throughout the experimental period, independent of energy density or flavor. Consequently, aggregate (summed) energy intake for subjects consuming low-fat ice cream was significantly lower (by 581 kJ (139 kcal), 15.4 g fat). Food intake records for the 24 h period immediately following the test sessions revealed no compensation for fat or energy. Despite the 28% reduction in energy density for the low-fat version, acceptance for the flavors associated with the reduced-energy versions had not declined by the end of the experimental period. CONCLUSIONS: The findings suggest that acceptance of reduced-fat foods may not be critically dependent on the post-ingestive metabolic effects when the reductions in energy density are small. Further tests with more severe reductions, and perhaps over more prolonged time periods, will be necessary to determine at what level of substitution acceptance might begin to deteriorate.

Adult↗
PubMed1998

Satiating effect of proteins in healthy subjects: a comparison of egg albumin, casein, gelatin, soy protein, pea protein, and wheat gluten.

The influence of six dietary protein types (egg albumin, casein, gelatin, soy protein, pea protein, and wheat gluten) on satiety and food intake was investigated. Twelve healthy subjects ingested six protein-manipulated lunches (approximately 5.2 MJ, 22% of energy as protein) according to a within-subjects design. Test meals were controlled for energy, macronutrients, fiber, and palatability. Nearly 65% of total protein varied between sessions. After lunch, satiety was assessed for 8 h and energy and macronutrients intakes were measured for 24 h. Blood was collected for determination of postprandial plasma glucose and insulin responses. Results showed no effect of the type of protein on satiety, on 24-h energy or macronutrient intakes, or on postprandial plasma glucose and insulin concentrations. These findings differ in part from those obtained previously in humans, which suggested that proteins may be differentiated in terms of their satiating capacities. We conclude that varying the protein source in a mixed meal does not affect food behavior in healthy humans, probably because coingestion of carbohydrate and fat with protein buffers the kinetics of the physiologic mechanisms implicated in postprandial satiety after a protein load.

Adult↗
PubMed1998

Dietary amylose-amylopectin starch content affects glucose and lipid metabolism in adipocytes of normal and diabetic rats.

The aim of this study was to evaluate the effects of the chronic consumption of two starches, characterized by different glycemic indices and amylose-amylopectin content, on glucose metabolism in rat epididymal adipocytes. The two chosen starches were from mung bean (32% amylose) and cornstarch (0.5% amylose). The alpha-amylase digestibility was higher for the waxy cornstarch than that of the mung bean starch (60 +/- 4 vs. 45 +/- 3%, mean +/- SEM, respectively). The glycemic index of the waxy cornstarch diet (575 g starch /kg diet) was higher than that of the mung bean starch diet (107 +/- 7 vs. 67 +/- 5%, P < 0.01) when measured in vivo in two groups of normal rats (n = 9). In a subsequent study, normal and diabetic (streptozotocin-injected on d 2 of life) male Sprague-Dawley rats (18 per group) consumed a diet containing 575 g starch/kg diet as either waxy cornstarch or mung bean starch. After 3 wk, food intake, epididymal fat pad weights, and plasma glucose, insulin and triglyceride concentrations did not differ between diet groups. Adipocyte diameter was smaller in rats that consumed mung bean starch compared with those that consumed the waxy cornstarch diet (P < 0.01). The mung bean diet increased maximal insulin-stimulated 14C-glucose oxidation (% of basal values, P < 0. 05). In contrast, incorporation of 14C-glucose into total lipids was significantly lower in rats that consumed the mung bean diet (P < 0. 05). We conclude that in both normal and diabetic rats, the chronic replacement of a high glycemic index starch by a low glycemic index one in a mixed diet increases insulin-stimulated glucose oxidation, decreases glucose incorporation into total lipids and decreases epididymal adipocyte diameter. Thus, the type of starch mixed into the diet has important metabolic consequences at the cellular level in both normal and diabetic rats.

Adipocytes↗
PubMed1998

A high glycemic index starch diet affects lipid storage-related enzymes in normal and to a lesser extent in diabetic rats.

The of this study was to evaluate the chronic effects of a high (waxy corn) vs. a low (mung beans) glycemic index starch diet on the lipogenic enzymes, fatty acid synthase (FAS) and lipoprotein lipase (LPL). Normal and diabetic (streptozotocin-injected on d 2 of life) male Sprague-Dawley rats consumed a diet containing 575 g/kg carbohydrates either as waxy cornstarch (WCS) or as mung bean starch (MBS). After 3 wk, neither body weights nor relative epididymal fat pad weights differed. In diabetic rats, the WCS diet induced high basal plasma insulin levels. Plasma triglycerides were not significantly affected by diet in either normal or diabetic rats. Adipose tissue and liver LPL activities were not modified by the type of starch in the diet. In normal rats, FAS activity and gene expression in epididymal adipose tissue but not in liver were greater in rats consuming the WCS diet than in those consuming MBS. To evaluate the implication of insulin in this regulation, two genes regulated by insulin [GLUT4 and phosphoenolpyruvate carboxykinase (PEPCK)] were also studied. The high glycemic index WCS diet compared with the low glycemic index MBS diet resulted in lower hepatic PEPCK mRNA in both normal and diabetic rats. Normal, but not diabetic rats fed WCS had greater GLUT4 gene expression in adipocytes than did those fed MBS. We conclude that the total replacement of 575 g/kg low glycemic index starch by a high glycemic index starch for 3 wk caused the following in normal rats: 1) high FAS activity and mRNA in adipose tissue but not in liver and 2) high GLUT4 gene expression in adipose tissue. In both normal and diabetic rats this same diet resulted in lower hepatic PEPCK mRNA. Therefore, high glycemic index starch diet is implicated in stimulating FAS activity and lipogenesis and might have undesirable long-term metabolic effects.

Adipose Tissue↗
PubMed1998

Plasma lipids and fatty acid synthase activity are regulated by short-chain fructo-oligosaccharides in sucrose-fed insulin-resistant rats.

The aim of this study was to evaluate the chronic effects of a short-chain fructo-oligosaccharide (FOS)-containing diet on plasma lipids and the activity of fatty acid synthase (FAS) in insulin-resistant rats. Normal male Sprague-Dawley rats, 5 wk old, were randomly assigned to two groups and fed either a sucrose-rich diet (S, 575 g sucrose /kg diet and 140 g lipids/kg diet) or a sucrose-rich diet supplemented with 10 g/100 g short-chain fructo-oligosaccharides (S/FOS). A third reference group (R) was fed a standard nonpurified diet (g/kg, 575 g starch, 50 g fat). After 3 wk the sucrose-fed rats (compared with the R group) were characterized by the following: 1) higher insulin responses after a glucose challenge (P < 0.05); 2) heavier liver (P < 0.001) and retroperitoneal adipose tissue (P < 0.01); 3) hypertriglyceridemia (P < 0.0001) and higher plasma free fatty acids (P < 0.0001); and 4) higher fatty acid synthase activity in the liver but a low activity in the adipose tissue (P < 0.001). The addition of FOS to the diet resulted in 11% lower liver weight than in the S group (P < 0.05) and tended to result in lower adipose tissue weight (P < 0.11). Plasma triglycerides and plasma free fatty acids were lower in S/FOS- than in S-fed rats (P < 0.05). Chylomicrons + VLDL, and intermediate density lipoprotein (IDL) concentrations did not differ between groups, nor was plasma cholesterol influenced by diet. Hepatic FAS activity was lower in S/FOS-fed rats than in the S-fed rats (P < 0.05). In adipose tissue, however, this activity tended to be greater in rats fed S/FOS than in rats fed the S diet (P < 0.07). In conclusion, in a rat model of diet-induced (57.5% sucrose and 14% lipids) insulin resistance, the addition of short-chain FOS prevented some lipid disorders, lowered fatty acid synthase activity in the liver and tended to raise this activity in the adipose tissue. Short-chain FOS, in addition to being a nondigestible sweetener with good bulking capacity, might be useful in the treatment of insulin resistance and hyperlipidemia.

Animals↗
PubMed1998

Moderate intake of n-3 fatty acids for 2 months has no detrimental effect on glucose metabolism and could ameliorate the lipid profile in type 2 diabetic men. Results of a controlled study.

OBJECTIVE: To evaluate the effect of a moderate dose of fish oil on glycemic control and in vivo insulin action in type 2 diabetic men with elevated plasma triacylglycerols and to determine the effect of the same treatment on gene expression of GLUT4, lipoprotein lipase (LPL), and hormone-sensitive lipase (HSL) in the abdominal adipose tissue. RESEARCH DESIGN AND METHODS: A total of 12 type 2 diabetic men were randomly allocated to 2 months of 6 g daily of either fish oil or sunflower oil, separated by a 2-month washout interval, in a double-blind crossover design. RESULTS: For glucose metabolism, 2 months of fish oil supplementation compared with sunflower oil led to similar fasting plasma insulin, glucose, and HbA1c. Basal hepatic glucose production did not increase after fish oil. There was no difference in insulin suppression of hepatic glucose production nor in insulin stimulation of whole-body glucose disposal measured by the euglycemic-hyperinsulinemic clamp. Fish oil did not ameliorate the low mRNA level of GLUT4 in adipose tissue of these patients. For lipid profile, fish oil lowered plasma triacylglycerol more than sunflower oil (P < 0.05) and tended to increase the amount of mRNA of both LPL and HSL in adipose tissue. CONCLUSIONS: A moderate dose of fish oil did not lead to deleterious effects on glycemic control or whole-body insulin sensitivity in type 2 diabetic men, with preserved triacylglycerol-lowering capacities.

Basal Metabolism↗