Bernhard Ludvik

Improvement in Glucose Tolerance and Insulin Resistance in Obese Subjects Treated with Troglitazone

BACKGROUND Troglitazone decreases insulin resistance and hyperglycemia in patients with non-insulin-dependent diabetes mellitus (NIDDM), but its effects on subjects without diabetes are not known. METHODS We performed oral and intravenous glucose-tolerance tests, studies with the euglycemic-hyperinsulinemic clamp, meal-tolerance tests, and 24-hour blood-pressure measurements at base line and after the administration of troglitazone, 200 mg orally twice daily, or placebo for 12 weeks in 18 nondiabetic obese subjects, 9 of whom had impaired glucose tolerance. RESULTS The mean (+/- SD) rates of glucose disposal increased from 4.7 +/- 1.7 to 6.0 +/- 1.7 mg per kilogram of body weight per minute (P = 0.004) and from 9.0 +/- 1.8 to 9.9 +/- 1.3 mg per kilogram per minute (P = 0.02) during insulin infusions of 40 and 300 mU per square meter of body-surface area per minute, respectively, in the troglitazone group. The insulin-sensitivity index, calculated from the results of intravenous glucose-tolerance tests, increased from 0.7 +/- 0.6 x 10(-4) to 1.6 +/- 0.9 x 10(-4) in subjects given troglitazone, and their glycemic response to oral glucose and to mixed meals decreased. The mean fasting plasma insulin concentration decreased by 48 percent (P = 0.002), and the plasma insulin response to oral glucose and mixed meals decreased by 40 and 41 percent, respectively. The changes were similar in the subjects with normal glucose tolerance and those with impaired glucose tolerance. Systolic and diastolic blood pressure decreased by 5 +/- 2 mm Hg (P = 0.05) and 4 +/- 2 mm Hg (P = 0.04), respectively, after treatment with troglitazone. There were virtually no changes in the placebo group. CONCLUSIONS Troglitazone decreases insulin resistance and improves glucose tolerance in obese subjects with either impaired or normal glucose tolerance. The ability of troglitazone to reduce insulin resistance could be useful in preventing NIDDM:

Sleeve gastrectomy and gastric banding: effects on plasma ghrelin levels.

Background: Different changes of plasma ghrelin levels have been reported following gastric banding, Roux-en-Y gastric bypass, and biliopancreatic diversion. Methods: This prospective study compares plasma ghrelin levels and weight loss following laparoscopic sleeve gastrectomy (LSG) and laparoscopic adjustable gastric banding (LAGB) in 20 patients. Results: Patients who underwent LSG (n=10) showed a significant decrease of plasma ghrelin at day 1 compared to preoperative values (35.8 ± 12.3 fmol/ml vs 109.6 ± 32.6 fmol/ml, P=0.005). Plasma ghrelin remained low and stable at 1 and 6 months postoperatively. In contrast, no change of plasma ghrelin at day 1 (71.8 ± 35.3 fmol/ml vs 73.7 ± 24.8 fmol/ml, P=0.441) was found in patients after LAGB (n=10). Increased plasma ghrelin levels compared with the preoperative levels at 1 (101.9 ± 30.3 fmol/ml vs 73.7 ± 24.8 fmol/ml, P=0.028) and 6 months (104.9 ± 51.1 fmol/ml vs 73.7 ± 24.8 fmol/ml, P=0.012) after surgery were observed. Mean excess weight loss was higher in the LSG group at 1 (30 ± 13% vs 17 ± 7%, P=0.005) and 6 months (61 ± 16% vs 29 ± 11%, P=0.001) compared with the LAGB group. Conclusions: As a consequence of resection of the gastric fundus, the predominant area of human ghrelin production, ghrelin is significantly reduced after LSG but not after LAGB. This reduction remains stable at follow-up 6 months postoperatively, which may contribute to the superior weight loss when compared with LAGB.

Does Gastric Dilatation Limit the Success of Sleeve Gastrectomy as a Sole Operation for Morbid Obesity

Background: Sleeve gastrectomy as the sole bariatric operation has been reported for high-risk super-obese patients or as first-step followed by Roux-en-Y gastric bypass (RYGBP) or duodenal switch (DS) in super-super obese patients. The efficacy of laparoscopic sleeve gastrectomy (LSG) for morbidly obese patients with a BMI of <50 kg/m2 and the incidence of gastric dilatation following LSG have not yet been investigated. Methods: 23 patients (15 morbidly obese, 8 super-obese) were studied prospectively for weight loss following LSG. The incidence of sleeve dilatation was assessed by upper GI contrast studies in patients with a follow-up of >12 months. Results: Patients who underwent LSG achieved a mean excess weight loss (EWL) at 6 and 12 months postoperatively of 46% and 56%, respectively. No significant differences were observed in %EWL comparing obese and super-obese patients. At a mean follow-up of 20 months, dilatation of the gastric sleeve was found in 1 patient and weight regain after initial successful weight loss in 3 of the 23 patients. Conclusion: LSG has been highly effective for weight reduction for morbid obesity even as the sole bariatric operation. Gastric dilatation was found in only 1 patient in this short-term follow-up. Weight regain following LSG may require conversion to RYGBP or DS. Follow-up will be necessary to evaluate long-term results.

CC Chemokine and CC Chemokine Receptor Profiles in Visceral and Subcutaneous Adipose Tissue Are Altered in Human Obesity

BACKGROUND/AIMS Obesity is associated with a low-grade inflammation, insulin resistance, and macrophage infiltration of adipose tissue. The role of CC chemokines and their respective receptors in human adipose tissue inflammation remains to be determined. METHODS sc and visceral adipose tissue of obese patients (body mass index 53.1 +/- 11.3 kg/m(2)) compared with lean controls (body mass index 25.9 +/- 3.8 kg/m(2)) was analyzed for alterations in inflammatory gene expression. RESULTS Macrophage infiltration was increased in sc and visceral adipose tissue of obese patients as determined by increased mRNA expression of a macrophage-specific marker (CD68) and by elevated macrophage infiltration. Gene expression of CC chemokines involved in monocyte chemotaxis (CCL2, CCL3, CCL5, CCL7, CCL8, and CCL11) and their receptors (CCR1, CCR2, CCR3, and CCR5) was higher in sc and visceral adipose tissue of obese patients. Serum concentrations of the inflammatory marker IL-6 and C-reactive protein were elevated in obese patients compared with lean controls. Obese patients revealed increased insulin resistance as assessed by the homeostasis model assessment of insulin resistance index and reduced plasma adiponectin concentrations. Adipose tissue expression of many CC chemokines and their receptors in the obese group positively correlated with CD68 expression. CONCLUSION Up-regulation of the CC chemokines and their respective receptors in adipose tissue occurs in human obesity and is associated with increased systemic inflammation.

Pronounced Insulin Resistance and Inadequate β-cell Secretion Characterize Lean Gestational Diabetes During and After Pregnancy

OBJECTIVE To evaluate β-cell secretion and glucose metabolism in lean subjects with gestational diabetes mellitus (GDM) compared with that in subjects with normal pregnancy and obesity. RESEARCH DESIGN AND METHODS Insulin secretion, insulin sensitivity (S1), and hepatic insulin extraction were assessed in pregnant women with GDM before and after delivery and in those with normal glucose tolerance (NGT) in comparison to healthy nonpregnant lean and obese women. Kinetic analysis of glucose, insulin, and C-peptide plasma concentrations during oral and intravenous glucose tolerance tests was performed by mathematical modeling. RESULTS S1 was blunted in pregnant women with GDM by 84% and in those with NGT by 66% compared with lean nonpregnant women (P < 0.005 vs. healthy nonpregnant lean control subjects; P < 0.05, GDM vs. pregnant women with NGT), whereas glucose effectiveness was decreased by 33% in both pregnant groups (P < 0.05 vs. healthy nonpregnant lean control subjects). Insulin secretion was 30% higher (P < 0.05) in subjects with GDM than in pregnant women with NGT or in nonpregnant lean women, but decreased (P < 0.005) when compared with obese women with a comparable degree of insulin resistance. Fractional hepatic insulin extraction was similar in both pregnant groups, being lower (P < 0.0001) by 30% versus nonpregnant females. β-cell sensitivity to glucose for insulin release was decreased in subjects with GDM versus pregnant women with NGT as well as nonpregnant women by 40-50% (P < 0.01). Twelve weeks after delivery, GDM returned to normal glucose tolerance, but S1 remained 50% lower than that in lean nonpregnant women, while β-cell sensitivity to glucose did not change (P < 0.01 vs. healthy nonpregnant lean control subjects). CONCLUSIONS Pregnancy is characterized by insulin resistance, diminished hepatic insulin extraction, and glucose effectiveness. Lean subjects with GDM are additionally characterized by having more pronounced insulin resistance and inadequate insulin secretion, which persist after delivery. Compared with other insulin-resistant prediabetic states like impaired glucose tolerance (IGT), defective insulin secretion seems to be a predominant defect in lean GDM subjects, indicating that it might represent a specific prediabetic condition.

Basal and stimulated plasma levels of pancreatic amylin indicate its co-secretion with insulin in humans.

SummaryAmylin is a 37-amino acid pancreatic polypeptide, probably involved in the pathophysiology of Type 2 (non-insulin-dependent) diabetes mellitus. We have determined amylin in human plasma by extraction-based radioimmunoassay (Sep-Pak C18). Of 23 healthy control subjects plasma amylin was determined as 11.9+-3.5 ng/l. Of 27 patients with Type 2 diabetes receiving insulin the amylin levels were lower, and in 16 patients with Type 2 diabetes on oral medication they were higher than in the control subjects: 8.2+-4.4 ng/l (p<0.01) vs 18.8+-9.9 ng/l (p<0.05). In 14 Type 1 (insulin-dependent) diabetic patients we found extremely low mean amounts of amylin: 2.9+-1.9 ng/l (p<0.002). Thus, basal amylin appears to be associated with the capacity to release insulin. An oral glucose load stimulated the release of amylin, this was more pronounced in patients with Type 2 diabetes than in healthy subjects. An excellent correlation of mean amylin with mean insulin concentrations was obtained (r=0.949). In patients with Type 2 diabetes amylin was reduced congruent to a decrease in C-peptide during a hyperinsulinaemic, euglycaemic glucose clamp experiment (r=0.971 for linear correlation between C-peptide levels and amylin). We conclude, that amylin and insulin are co-secreted in humans, and that the amylin release is under feedback-control by insulin.

Increased plasma leptin in gestational diabetes

Aims/hypothesis. Insulin resistance as well as marked changes in body weight and energy metabolism are associated with pregnancy. Its impact on plasma leptin is not known and was determined in this longitudinal study in both diabetic and normal pregnancy. Methods. At 28 gestational weeks plasma concentrations of leptin and B-cell hormones were measured at fasting and after an oral glucose load (OGTT:75 g) in women with gestational diabetes and pregnant women with normal glucose tolerance and compared with women who were not pregnant (C). Results. Plasma leptin (ng/ml) was higher (p < 0.001) in women with gestational diabetes (24.9 ± 1.6) than in women with normal glucose tolerance (18.2 ± 1.5) and increased in both groups when compared with the non-pregnant women (8.2 ± 1.3; p < 0.0005). No change in plasma leptin concentrations was induced by OGTT in any group. Basal insulin release was higher (p < 0.05) in women with gestational diabetes compared with the pregnant women with normal glucose tolerance. Marked insulin resistance was confirmed by a 20 % lower (p < 0.05) insulin sensitivity in subgroup analysis and a decrease of almost 40 % in fasting glucose/insulin ratio (p < 0.005) in women with gestational diabetes. Leptin correlated in women with gestational diabetes with basal plasma concentrations of glucose (p < 0.02), insulin (p < 0.004) and proinsulin (p < 0.01) as well as with BMI (p < 0.001) and overall pregnancy induced maternal weight gain (p < 0.009). With normalisation of blood glucose 8 weeks after delivery in women with gestational diabetes their plasma leptin decreased (p < 0.0005) to 17.3 ± 1.9 ng/ml but did not completely normalize (p < 0.05 vs non-pregnant women). Conclusion/interpretation. Our data show that women with gestational diabetes without any change in plasma leptin upon oral glucose loading have increased plasma leptin concentrations during and after pregnancy, a clear association of plasma leptin with the respective concentration of glucose and insulin resistance as well as with changes in body weight, and a failure to normalize spontaneously BMI to the same extent as pregnant women with normal glucose tolerance when compared with matched control subjects. [Diabetologia (2001) 44: 164–172]

Feasibility of a Mobile Phone–Based Data Service for Functional Insulin Treatment of Type 1 Diabetes Mellitus Patients

Background Patients with type 1 diabetes mellitus (DM1) have to be active participants in their treatment because they are inevitably responsible for their own day-to-day-care. Availability of mobile Internet access is advancing rapidly and mobile phones are now widely available at low cost. Thus, mobile phones have the potential to assist in daily diabetes management and to enable a telemedical interaction between patients and health care professionals. Objective The aim of the study was to evaluate the feasibility and user acceptance of a mobile phone–based data service to assist DM1 patients on intensive insulin treatment. Methods A software application called Diab-Memory (based on Java 2 Mobile Edition) has been developed to support patients when entering diabetes-related data with synchronization to the remote database at the monitoring center. The data were then processed to generate statistics and trends, which were provided for the patient and his/her health care professional via a Web portal. The system has been evaluated in the course of a clinical before-after pilot trial. Outcome measures focused on patients’ adherence to the therapy, availability of the monitoring system, and the effects on metabolic status. General user acceptance of the system was evaluated using a questionnaire. Results Ten patients (four female) with DM1 participated in the trial. Mean age was 36.6 years (± 11.0 years) and prestudy glycated hemoglobin (HbA1c) was 7.9% (± 1.1%). A total of 3850 log-ins were registered during the 3 months of the study. The total number of received datasets was 13003, which equates to an average of 14 transmitted parameters per patient per day. The service was well accepted by the patients (no dropouts), and data transmission via mobile phone was successful on the first attempt in 96.5% of cases. Upon completion of the study, a statistically significant improvement in metabolic control was observed (HbA1c: prestudy 7.9% ± 1.1% versus poststudy 7.5% ± 0.9%;P= .02). While there was a slight decrease in average blood glucose level (prestudy 141.8 mg/dL ± 22.5 mg/dL vs poststudy 141.2 mg/dL ± 23.1 mg/dL;P= .69), the difference was not statistically significant. Conclusion The results of the clinical pilot trial indicate that this proposed diabetes management system was well accepted by the patients and practical for daily usage. Thus, using the mobile phone as patient terminal seems to provide a ubiquitous, easy-to-use, and cost efficient solution for patient-centered data acquisition in the management of DM1. To confirm the promising results of the pilot trial further research has to be done to study long-term effects on glycemic control and cost-effectiveness.

Effect of Obesity on Insulin Resistance in Normal Subjects and Patients With NIDDM

Insulin resistance (IR) is a characteristic feature of non-insulin-dependent diabetes mellitus (NIDDM) as well as obesity, and a majority of NIDDM patients are obese. To assess the effect of obesity independent of NIDDM on IR, we studied the relationship between IR and obesity in 65 normal and 58 NIDDM subjects; we used body mass index (BMI) as a measure of obesity and glucose infusion rate (GINF) during a euglycemic hyperinsulinemic (120 mU · m−2 · min−1) glucose clamp as a measure of IR. In lean normal subjects, GINF was 57.7 ± 2.2 μmol · kg−1 · min−1 (10.4 ± 0.4 mg · kg−1 · min−1) and the lean NIDDM subjects were markedly insulin-resistant, with a GINF of 34.4 ± 2.8 μmol · kg−1 · min−1 (6.2 ± 0.5 mg · kg−1 · min−1). Obese normal subjects were also insulin-resistant compared with lean normal subjects, with a GINF of 36.1 ± 2.2 μmol · kg−1 · min−1 (6.5 ± 0.4 mg · kg−1 · min−1), and obesity caused an increase in IR in NIDDM, with a GINF of 21.1 ± 1.4 μmol · kg−1 · min−1 (3.8 ± 0.25 mg · kg−1 · min−1) in the obese NIDDM subjects. Therefore, ∼61% of the IR in obese NIDDM subjects is due to NIDDM, with 39% due to obesity, demonstrating a greater impact of NIDDM than of obesity in causing IR. The correlation between GINF and BMI was much better in normal subjects (r = −0.75) than in NIDDM subjects (r = −0.50) as was the relationship between fasting insulin level and BMI (r = −0.59 in normal subjects, r = −0.48 in NIDDM subjects). As expected, the fasting insulin level was also strongly correlated to GINF in normal subjects (r = −0.61); however, this relationship was weaker in NIDDM subjects (r = −0.46). In conclusion, 1) obesity has a major impact to cause insulin resistance in nondiabetic subjects, but the effect of obesity on IR in NIDDM is less; 2) NIDDM per se is the major contributor to IR in NIDDM; and 3) the fasting insulin level is a better surrogate marker of IR in nondiabetic subjects than in NIDDM patients.

Impact of laparoscopic adjustable gastric banding on plasma ghrelin, eating behaviour and body weight

Background  Plasma ghrelin, an orexigenic peptide derived from the stomach and duodenum, increases following weight loss and might contribute to weight regain. The aim of the present study was to evaluate the effect of laparoscopic adjustable gastric banding (LAGB) on body weight and body composition as well as plasma ghrelin in relation to eating behaviour in morbidly obese patients.