PubMed Health⌕ Search

Biomedical subjects

J Bringer

Publications and source records attributed to J Bringer.

At least 19 recordsLinked to original sources
PubMed2006

Resting energy expenditure and fuel metabolism following laparoscopic adjustable gastric banding in severely obese women: relationships with excess weight lost.

BACKGROUND: Although adjustable gastric banding is increasingly proposed for massively obese patients, little is known about the modifications of resting metabolic rate and substrate oxidation or about metabolic determinants of weight loss following this type of bariatric surgery. OBJECTIVES: To evaluate the relationships between excess weight loss, resting metabolic rate (RMR) and substrate oxidation, and to identify metabolic predictive factors of weight loss after adjustable gastric banding. SUBJECTS: Seventy-three obese nondiabetic women aged 39.1+/-10.4 years (18.4-64.8). DESIGN: Resting metabolic rate and substrate oxidation (indirect calorimetry), body composition (bio-impedance), lipid profile and insulin sensitivity indexes were assessed before and after (13.3+/-6.0 months, range 6.0-31.1) adjustable gastric banding. Patients were classified according to postsurgery time: group A (6-12 months, n=39); group B (12-18 months, n=21); group C (>18 months, n=13). Metabolic parameters associated with the percentage of excess weight lost (EWL) 1 year after surgery were analyzed in univariate and multivariate regressions. RESULTS: Mean weight loss was 26.2+/-11.4 kg. Mean fat mass loss was 17.3+/-8.1 kg. All biological parameters associated with excess weight improved after surgery. Excess weight lost at 1 year was 45.9+/-17.1% in group A, 47.4+/-17.1% in group B and 51.4+/-18.5% in group C (P=NS). Resting metabolic rate/fat-free mass (FFM) slightly decreased (28.9+/-3.26 vs 30.3+/-2.8, P<0.00001) and RMR/body weight slightly increased (18.5+/-2.8 vs 17.3+/-1.9, P<0.00001) after surgery. Respiratory quotient (0.81+/-0.06 vs 0.82+/-0.05) and FFM-adjusted lipid oxidation (1.10+/-0.41 vs 1.05+/-0.33 mg/min/kg FFM) were not significantly modified after surgery. In multiple linear regression analysis, difference in RMR/body weight, difference in energy sparing, baseline BMI and postsurgery time, were significantly and independently correlated with EWL (total R2=72.5%). CONCLUSIONS: Adjustable gastric banding promotes gradual but sustained weight loss and is associated with long-term conservation of lipid oxidation and energy expenditure. The individual variability in energy sparing mechanisms predicts weight loss during the first year after surgery.

Adolescent↗
PubMed2006

Artificial beta-cell: clinical experience toward an implantable closed-loop insulin delivery system.

AIM: Restoration of long-term normal blood glucose control in diabetic patients supports the elaboration of an artificial beta cell. The possibility of implantation of the three crucial components of such a system (insulin delivery device, glucose sensor and controller) is analyzed. METHODS: The Long-Term Sensor System project, aiming at a fully implantable artificial beta cell, assessed the feasibility of glucose control by the combined implantation of a pump for peritoneal insulin delivery and a central intravenous glucose sensor close to the right atrium, connected via a subcutaneous lead. It was initiated in 10 Type 1 diabetic patients in our clinic from 2000. Data obtained during this experience are reviewed and confronted to reported closed-loop trials using other approaches. RESULTS: No significant complication related to prolonged implantation of intravenous sensors occurred and the combined implants were well tolerated. Glucose measurement by the intravenous sensors correlated well with meter values (r=0.83-0.93, with a mean absolute deviation of 16.5%) and accuracy has been sustained for an average duration of 9 months. Uploading of pump electronics by algorithms designed for closed-loop insulin delivery allowed in-patient 48 hour-trials aiming at automated glucose control. Glucose control was similar to that reported by investigations combining subcutaneous sensors to wearable pumps for subcutaneous insulin infusion. The benefits of more physiological insulin kinetics due to intra-peritoneal delivery have been hampered by the slow response time of intravenous sensors. CONCLUSION: Although the concept of a fully implantable artificial beta cell has been validated as feasible, the limited performance in achieving glucose control requests improvements in the sensor structure to increase its longevity and decrease sensor delay.

Clinical Trials as Topic↗
PubMed2006

Accuracy of continuous subcutaneous glucose monitoring with the GlucoDay in type 1 diabetic patients treated by subcutaneous insulin infusion during exercise of low versus high intensity.

AIM: The GlucoDay allows continuous glucose monitoring by subcutaneous microdialysis in sedentary conditions. To validate it when glycaemia may undergo rapid and dramatic changes, we investigated its accuracy during two exercise sessions with markedly different glucose disposal rates. METHODS: Nine male diabetic patients, aged 32-61, treated by insulin pumps, first underwent a standard maximal exercise-test designed for determining the maximal oxygen consumption and the first ventilatory threshold (Vt1). Then two 30 min steady-state workloads at 15% below and 15% above the Vt1 were performed in random order with the GlucoDay, and measurement of CHO oxidation rates was made by indirect calorimetry. RESULTS: CHO oxidation during exercise at +15% Vt1 was higher (+943.5 mg/min, ie +45.5%, P<0.01) than during exercise at -15% Vt1 No hypoglycaemia occurred. Due to breakages of 39% of subcutaneous probes, eleven steady-state sessions in 7 subjects allowed to compare 141 paired glucose (sensor vs. venous) determinations. The Clarke error grid situates 92.9% of glucose values within the A zone and 6.4% within the B zone, while only one pair of values (0.7%) falls in the D zone. Venous glucose tended to decrease more rapidly than sensor glucose during exercise. Bland-Altman plots evidence for a few cases of underestimation of venous glucose at high intensity. CONCLUSIONS: This study showed satisfactory accuracy of the GlucoDay during exercise. A slight lag time in sensor values likely explains a few discrepancies that do not appear as clinically meaningful. Reduction of probe fragility and confirmed sensor accuracy in hypoglycaemia would further support applicability of GlucoDay at exercise.

Adult↗
PubMed2004

[Long-term risks of polycystic ovaries syndrome].

The prevalence of the polycystic ovaries syndrome (PCOS) is high but it is a heterogeneous disorder with implications in numerous medical domains. Abdominal obesity and insulin resistance, which are the main metabolic disorders, are strong links between hormonal abnormalities and long-term medical consequences. The latter begin to be better understood. Some studies suggest that PCOS may increase the risk for several conditions, including type 2 diabetes, dyslipidemia, hypertension, cardiovascular disease and some cancers.

Cardiovascular Diseases↗
PubMed2003

[Menopause: towards treatment "à la carte" ].

In spite of questioning and doubt arising from WHT study hormone substitution therapy (HST) has proven efficacy on climacteric symptoms and certain short-term and long-term consequences of menopause. Among 1000 women taking HST for ten years, eight supplementary cases of breast cancer and 6 fewer cases of colonic cancer are observed. No cardiovascular protection has been demonstrated. A history of coronary artery disease, vascular disease, stroke or thromboembolism are contraindications for HST. The vascular impact of estradiol administered via an extra-digestive route in women with a low vascular risk cannot be extrapolated from the HERS and WHI trials because these trials were conducted is high-risk women, using specific types of steroids given orally. Tibolone has demonstrated efficacy and in an alternative to HST after more than one year of menopause. The usefulness of phytoestrogens remains to be determined, particularly due to the wide individual variability of their effects on climacteric symptoms and the low level of proof provided by epidemiological or clinical studies conducted to study the prevention of osteoporosis and the risk of breast cancer. Most of the analyses present methodological biases. Currently, the most widely accepted notion is that there is a beneficial effect on cardiovascular risk. To date, SERMs have selective indications and cannot be prescribed for all women: raloxifen is used for the prevention and treatment of menopause-related osteoporosis. The relative risk of venous thromboembolism with SERMs (raloxifen and tamoxifen) is comparable to that observed with HST. HST or any other treatment given for menopause must be an individual decision balancing the benefits against the risks and taking into account the desires of the patient perfectly informed of the currently available evidence. Prescriptions should be part of an overall scheme including nutritional advise and physical exercise aimed at preserving quality of life and preventing age-related effects which largely depend on genetic predisposition and the psycho-affective environment.

Cardiovascular Diseases↗
PubMed2002

Simplified measurement of insulin sensitivity with the minimal model procedure in type 2 diabetic patients without measurement of insulinemia.

This study aimed to evaluate a simplified minimal model protocol for measuring insulin sensitivity in mild and severe type 2 diabetes, considering that changes in serum insulin during an insulin-modified intravenous glucose tolerance test almost only reflect the insulin injection. Two groups of diabetics treated with high doses of antidiabetic agents were recruited. Mean insulin responses were calculated in group 1 (n = 30). In group 2 (n = 38), we compared insulin sensitivity (SI) obtained with reference protocol with SI calculated by a minimal model procedure including the theoretical average insulin profile determined in group 1, and with Homeostasis Model Assessment (HOMA-R). Additionally, the cost of each procedure was calculated. SI measured by the reference method strongly correlated with SI determined by the simplified protocol (r = 0.966, p < 0.0001), while no correlation was found with HOMA-R (r = - 0.349, NS). Reduction of cost for HOMA-R and simplified minimal model procedure were - 92 and - 81 %, respectively. This simplified and relative inexpensive protocol, using minimal model procedure without insulin measurement, accurately measures SI regardless of beta-cell defect degree. This approach could be of interest when limits of validity of simple indexes are reached.

Costs and Cost Analysis↗
PubMed2002

[From external to implantable insulin pump, can we close the loop?].

The project to finalize a 'closed loop' insulin delivery according to blood glucose level, i.e. an implanted artificial beta cell, is born from the development of the first miniaturized portable insulin pumps during the 1970s. Continuous improvements in micro-electronics, as well as in the development of biomaterials and stable insulin solutions, have led to the availability of implantable pumps able to infuse insulin by the peritoneal route, in a continuous and programmable way, for several years. These systems represent the most efficient and physiological mode of insulin therapy at the present time. More recently, we have demonstrated during clinical trials that intravascular, implantable, glucose sensors using glucose-oxidase were able to measure with good accuracy real-time blood glucose for several months. The combination of these two devices to form a prototype of implantable artificial beta cell, designated as Long Term Sensor System, allowed us to perform the first trials of closed-loop insulin delivery according to sensor signal for periods of 48 hours in type 1 diabetic patients. This mode of functioning appeared to be feasible and able to establish glucose control closer to physiology than the use of implantable pumps in open-loop, i.e. by adapting insulin delivery according to capillary blood glucose. Although algorithms tuning automated insulin delivery are improvable, the success of these initial trials materializes the perspective of a possible restoration of physiological insulin function by the mean of an implanted artificial beta cell in diabetic patients.

Blood Glucose↗
PubMed2002

[Obesity and pregnancy].

As the prevalence of obesity is currently increasing in Western countries, maternal obesity is one of the most frequently encountered high-risk obstetrical situations. Pregnancies in obese women are characterized by a high incidence of maternal (gestational diabetes, hypertensive disorders) and fetal (macrosomia, neural tube defects, late fetal deaths) complications. Because of those complications, cesarean sections rate is higher in obese women than in lean women. The occurrence of materno-fetal complications parallels the level of obesity, but even moderate overweight amplifies the risk. Long-term complications include worsening of maternal obesity, type 2 diabetes in the mother, and development of childhood obesity. Prenatal care should include a tight monitoring of weight gain and screening for gestational diabetes. Long term follow-up is necessary.

Female↗
PubMed2001

A prospective prognostic study of the hormonal milieu at the time of surgery in premenopausal breast carcinoma.

BACKGROUND: Despite numerous studies, the influence of timing at surgery in relation to the menstrual cycle on the prognosis of breast carcinoma is still controversial. Most studies are retrospective, and the reliability of the menstrual history data is limited by the lack of hormonal assessment at the time of surgery. The authors prospectively studied the influence of the menstrual cycle phase as determined by circulating hormones at the time of surgery on the outcome of breast carcinoma. METHODS: A population of 360 premenopausal women with nonmetastatic breast carcinoma operated on from 1992 to 1995 was analyzed. Serum estradiol, progesterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) levels were assayed the day of surgery to define the menstrual cycle phase (follicular, n = 186; ovulatory, n = 24; luteal, n = 150). The mean follow-up was 48 months. RESULTS: There were no relations between the menstrual phase at surgery and tumor size, cathepsin D level, Scarff-Bloom-Richardson grade, Pg receptor (PgR), and the number of positive lymph nodes. The mean estrogen receptor level was higher during the follicular phase than in the ovulatory and luteal phases (P < 0.02). Univariate analysis of recurrence free survival (RFS) and overall survival (OS) showed no relations with the menstrual phase or the level of estradiol and progesterone at the time of surgery. High LH or FSH levels (above the medians) were associated with shorter RFS (P = 0.02 and P = 0.04, respectively) or OS (P < or = 0.01 and P = 0.01, respectively). In multivariate analysis, lymph node status, PgR status and LH level were the most significant parameters for predicting OS. There appeared to be no survival differences between menstrual cycle groups after stratification by lymph node status. CONCLUSIONS: This prospective study showed a lack of prognostic value of timing at surgery in relation to the menstrual period or to estrogen and progesterone levels in premenopausal breast carcinoma. Conversely, high gonadotropin levels could predict OS independently of other prognostic factors.

Breast Neoplasms↗
PubMed2001

Role of allelic variants Gly972Arg of IRS-1 and Gly1057Asp of IRS-2 in moderate-to-severe insulin resistance of women with polycystic ovary syndrome.

To assess the role of insulin receptor, insulin receptor substrate (IRS)-1, and IRS-2 genes in insulin resistance, we explored the genomic DNA in women with polycystic ovary syndrome (PCOS) and a variable degree (mean +/- SE) of insulin resistance (homeostasis model assessment index for insulin resistance [HOMA(IR)] 3.2 +/- 0.6, n = 53; control subjects 1.56 +/- 0.34, n = 102) using direct sequencing. Whereas no novel mutations were found in these genes, gene-dosage effects were found on fasting insulin for the Gly972Arg IRS-1 variant and on 2-h plasma glucose for the Gly1057Asp IRS-2 variant. The Gly972Arg IRS-1 variant was more prevalent in insulin-resistant patients compared with non-insulin-resistant individuals or control subjects (39.3 vs. 4.0 and 16.6%, P < 0.0031, respectively). A multivariate model that included BMI as a variable revealed significant effects of the Gly1057Asp IRS-2 variant on insulin resistance (P < 0.016, odds ratio [OR] 7.2, 95% CI 1.29-43.3). HOMA(IR) was higher in carriers of both IRS variants than in those with IRS-2 mutations only or those with wild-type variants (6.2 +/- 2.3, 2.8 +/- 0.5, and 1.8 +/- 0.2, respectively; P < 0.01), and it was significantly associated with this genotype (P < 0.0085, OR 1.7, 95% CI 1.09-2.99). We conclude that polymorphic alleles of both IRS-1 and IRS-2, alone or in combination, may have a functional impact on the insulin-resistant component of PCOS.

Adult↗
PubMed2001

Implantable insulin pumps: infections most likely due to seeding from skin flora determine severe outcomes of pump-pocket seromas.

Complications at implantation site of implantable insulin pumps may lead to premature removal. To elucidate the origins and the outcomes of these local adverse events. We investigated seromas of the 'pump-pocket' that have been detected for an eight month-period during the follow-up of such-treated forty type 1 diabetic patients. At the start of study period, skin bacterial flora was sampled at umbilicus and groin, and isolated strains of Staphylococcus epidermidis were preserved in specific vials at -20 degrees C. Each time a seroma was detected at transcutaneous 45 days-refill of pump reservoir, it was sampled for bacterial cultures. Isolated strains of S. epidermidis from seroma were genetically compared to preserved strains of corresponding patients using Pulsed-Field Gel Electrophoresis (PFGE) after genomic restriction by SmaI. Among the ten seromas that occurred after a mean time of 9.9 months since implantation, S. epidermidis were isolated in five cases. Genetic comparison of isolated strains could be performed in three cases. Compared strains showed identical (in 2 cases) or closely related (in one case) PFGE profiles. While the five aseptic seromas resolved with rest, four infected cases required explantations after one to nineteen months in spite of antibiotic therapy and the fifth one persisted without impairment under long-term antibiotics. Our results suggest that seeding from the skin flora is a key-factor determining the severity of pump-pocket complications. We recommend that bacterial investigations of pump-pocket seromas should be systematically performed, while prophylactic measures might include antibiotic cover for each puncture of the pump-pocket.

Adult↗
PubMed2001

[Insulin sensitivity and polycystic ovarian syndrome].

Insulinresistance, commonly associated with polycystic ovarian syndrome (PCOS), raises many unresolved debates about its prevalence, mechanism and true pathological role. Low insulin sensibility may have multiple origins among them genetic molecular defects in pathways of cellular insulin effects. A weight gain and android distribution of fat mass may reveal or increase insulin resistance and hyperinsulinemia. The preexisting unbalanced ovarian steroidogenesis secondary to abnormalities in gene coding for enzymes of P450C17 alpha might be the necessary support facilitating the stimulatory effect of hyperinsulinemia or other factors (LH, IGF1) on ovarian androgens. In practice, the phycisian has to know how to evaluate and to treat insulin resistance in view of its implication in dysovulation and, later on, metabolic and cardiovascular risks. Nutritional education and regular physical exercice are the necessary approaches. The efficacy and indications of metformin and thiazolidinediones have to be further evaluated.

Adipose Tissue↗
PubMed2001

Balance of substrate oxidation during submaximal exercise in lean and obese people.

OBJECTIVES: To compare fat and carbohydrate oxidation at different exercise intensities between overweight and normal-weight subjects, in order to analyze the influence of muscular metabolic abnormalities in obese people on substrate utilization during exercise. MATERIAL AND METHODS: 32 healthy sedentary overweight subjects (Body Mass Index (BMI): 30.8 +/- 0.8 kg/m(2); body fat: 37.4 +/- 1.1%; mean +/- SEM) and 26 controls (BMI: 23 +/- 0.4 kg/m(2); body fat: 22.7 +/- 1.1%) matched for age and sex were examined. The test consisted in four six-min. submaximal steady-state workloads with calculation of substrate oxidation rates and derived quantitative parameters, i.e., crossover point (defined as the power at which carbohydrate-derived energy becomes predominant) and maximal fat oxidation rate point. In addition, the accuracy of the test was analyzed and was found to be satisfactory. RESULTS: While exercise intensities were similar in both group, fat oxidation rates were significantly lower in overweight group (p<0.05). The crossover and the maximal fat oxidation rate points were significantly lower in overweight subjects than in controls: 33.3 +/- 2 vs 50.1 +/- 3.4% and 30.5 +/- 2.3 vs 44.6 +/- 3.3% of maximal aerobic power, respectively (p<0.001). CONCLUSION: Sedentary overweight subjects, compared to controls at the same exercise intensities, exhibited an alteration of the balance of substrate oxidation, reflected by lower rates of fat oxidation and a shift of quantitative parameters to lower intensities. The test appeared to be reliable and could be of interest to advise an individualized exercise prescription in obese people.

Adult↗
PubMed2001

[Which contraception to choose for the diabetic woman?].

Low-dose oral contraceptives can be used by a great number of women with IDDM or a previous gestational diabetes mellitus. Others hormonal contraceptives (progestogen-only preparations) are less convenient and the compliance is poor with an increasing risk of gynaecologic side effects. The safety of this contraceptives as regards vascular diabetic complications is not evaluated well. Nulliparous patients with progressive complications can use barrier methods of contraception after education. Macroprogestative contraception is a adequate choice for women within forties. For multiparous diabetic women, intra-uterine devices represent the first choice.

Contraceptives, Oral↗
PubMed2001

[Insulin therapy in type 1 diabetes for and during pregnancy: by which means and for which objectives?].

Clinical data in the 1980s showed a close relationship between the conceptional glycated hemoglobin and the occurrence of spontaneous early abortions and fetal malformations. Blood glucose level during pregnancy was similarly correlated with the risk of fetal macrosomia, due to significant links between birthweight, fetal hyperinsulinemia and mean maternal blood glucose. Tight blood glucose control from conception to term was shown to be able to lower the risk of fetal malformations and perinatal mortality to that of the offspring of a non diabetic mother. Prerequisites include: 1) contraception until tight blood glucose control, 2) close partnership between diabetologist and obstetrician, 3) assessment of diabetic complications. Seldom, coronary heart disease or advanced nephropathy contraindicate pregnancy. Uncontrolled proliferative or pre-proliferative retinopathy, or macular edema, are temporary contraindications to pregnancy. Laser photocoagulation must then be performed before tightening blood glucose control. A complete review of diabetes management is associated with therapeutic intensification. Blood glucose objectives allow as limits: 70 to 100 mg/dl before meals, up to 140 mg/dl one hour and 120 mg/dl two hours after meals. HbA1c allowing conception is close to 7%. Blood glucose monitoring requires 6-7 measurements per day. The most efficient insulin regimens include 3 to 4 shots per day. The distribution between regular and NPH or lente insulins is adapted individually. Lispro insulin, now appearing as safe, may be used to improve post-meal blood glucose control. Insulin pumps may be useful in case of late-night poor control or frequent hypoglycemic events. Patient acceptance of this option is unavoidable to obtain a benefit. Preconceptional insulin therapy must be maintained until pregnancy term. Follow-up must be intensified after twenty fourth week. Labor and delivery, cesarean section, fetal maturation by corticosteroids and use of i.v. betamimetic drugs require continuous i.v. insulin delivery. The continuation of intensive insulin management in post-partum is encouraged.

Blood Glucose↗
PubMed2000

Comparison of octreotide acetate LAR and lanreotide SR in patients with acromegaly.

BACKGROUND AND OBJECTIVE: The most effective option for the medical treatment of patients with acromegaly is the use of somatostatin analogues. Long-acting depot formulations for intramuscular injection of two somatostatin analogues have recently become available: octreotide acetate LAR (Sandostatin LAR, Novartis Pharma AG) and lanreotide SR (Somatuline, Ipsen Biotech). We wished to compare efficacy of octreotide LAR and lanreotide SR in acromegalic patients. PATIENTS AND METHODS: A group of 125 patients with acromegaly (67 females; mean age, 47 years; 59 patients had previous pituitary irradiation) from 26 medical centres in France, Spain and Germany were studied. Before the study, all patients had been treated with intramuscular injections of lanreotide SR (mean duration, 26 months) at a dose of 30 mg which was injected every 10 days in 64 and every 14 days in 61 patients, respectively. All patients were switched from lanreotide SR to intramuscular injections of 20 mg of octreotide LAR once monthly for three months. In order to obtain efficacy and safety data of lanreotide SR under study conditions, it was decided to randomly assign at day 1, in a 3 : 1 ratio, the time point of the treatment switch; 27 of the patients were randomly assigned to continue the lanreotide SR treatment for the first 3 months of the study (group A); they were on octreotide LAR 20 mg from month 4-6. The other 98 patients were assigned to be switched to treatment with octreotide LAR 20 mg at day 1 (group B). In group B patients, octreotide LAR treatment was continued until month 6, with an adjustment of the dose based on GH levels obtained at month 3. RESULTS: The mean GH concentration decreased from 9.6 +/- 1.3 mU/l at the last evaluation on lanreotide SR to 6.8 +/- 1.0 mU/l after three injections of octreotide LAR (P < 0.001). The percentages of patients with mean GH values < or = 6.5 mU/l (2.5 microg/l) and < or = 2.6 mU/l (1.0 microg/l) at the last evaluation on lanreotide SR were 54% and 14%, and these values increased after 3 months treatment with octreotide LAR to 68% and 35% (P < 0.001), respectively. IGF-I levels were normal in 48% at the last evaluation on lanreotide SR and in 65% after 3 months on octreotide LAR (P < 0.001). Patients with pre-study pituitary irradiation had lower mean GH and IGF-I concentrations. But the effects of the treatment change did not differ between the irradiated and the nonirradiated patients. In general both drugs were well tolerated. CONCLUSION: Octreotide LAR 20 mg administered once monthly was more effective than lanreotide SR 30 mg administered 2 or 3 times monthly in reducing GH and IGF-I in patients with acromegaly.

Acromegaly↗