Clinical practice recurrent severe obscure gastro intestinal-bleeding in a 20 year old man.

Morbus Osler-Weber-Rendu syndrome also known as Hereditary hemorrhagic telangiectasia (HHT) and Meckel's diverticulum is a rare combination disorder. Our case presented with the recurrent obscure gastrointestinal (GI) bleeding for several years. He came with a massive active lower gastrointestinal bleeding. Ultimatively, he underwent an exploratory laparotomy along with intraoperative colonoscopy. A Meckel's diverticulum in combination with multiple erosions was found as a probable cause of the massive gastrointestinal bleeding. An ileo-caeacal resection had been performed and by the pathologist multiple telangiectasias in the resected ileum were established. Blood was sent for genetics and was negative for ENG, ALK-1, and SMAD-4 genes. The patient was discharged after 10 days from time of admission and is under regular follow up without any further bleeding. In this case, despite sophisticated techniques for investigations the cause of the GI-bleeding with several esophagogastroduodenoscopies and colonoscopies, mesenteric angiography and finally an oral double balloon enteroscopy was misdiagnosed till the intra operative endoscopy showed a middle GI-bleeding. The management for obscure GI-bleeding is discussed for countries with lower medical facilities like Nepal in our case with Morbus Osler-Weber-Rendu syndrome.

Eosinophilic cholangitis and wirsungitis as cause of simultaneous bile duct obstruction and pancreatitis.

Eosinophilic cholangitis is a rare clinical entity characterised by transmural eosinophilic infiltration of the biliary system. The aetiology of this disease is still unclear. We report on a 49-year-old male patient who presented with symptoms of obstructive jaundice and imaging suggestive for periampullary carcinoma. After partial pancreatoduodenectomy for suspected pancreatic cancer, pathology revealed massive eosinophilic cholecystitis as well as intra- and extrahepatic eosinophilic cholangitis with pseudopolypoid papillary lesions. Our case illustrates the diagnostic pitfalls in eosinophilic cholangitis as careful imaging procedures - optimally interdisciplinary - should be considered and performed in such patients. In conclusion, eosinophilic cholangitis is an uncommon, inflammatory condition that needs to be considered as a differential diagnosis for periampullary malignancies.

Insulin interacts directly with Na⁺/K⁺ATPase and protects from digoxin toxicity.

Insulin has shown to have cardioprotective effect in diabetic patient after digoxin intoxication. The latter, prompted us to study whether insulin interacts directly with Na⁺/K⁺-ATPase. The interaction of insulin with Na⁺/K⁺-ATPase was explored using enzyme activity, Biacore and Western blot. We also used, flow cytometry, immunohistochemistry and chronotropy on both neonatal and adult rats cardiomyocytes. Insulin at concentration 1.7e⁻7 M blunted the effect of digoxin on Na⁺/K⁺-ATPase activity. In Western blot, the same insulin concentration decreased enzyme α subunit immunoreactivity. Insulin and digoxin decreased both enzyme α subunit immunoreactivity but insulin/digoxin co-treatment did not. Biacore confirmed a direct interaction between insulin and Na⁺/K⁺-ATPase. In neonatal rat cardiomyocytes, insulin plus digoxin induced cell apoptosis but not alone. In adult rat cardiomyocytes, insulin at optimal dose did not induce apoptosis but prevented the one induced by digoxin. In immunocytochemsitry both insulin and digoxin altered Na⁺/K⁺-ATPase α subunit immunoreactivity while their association did not. Finally, insulin increased the beating rate of neonatal rat cardiomyocytes (45±7 beats/min); so did digoxin (36±13 beats/min). The effect of insulin was prevented after pre-treated with digoxin. These results demonstrate that insulin interacts directly with Na⁺/K⁺-ATPase pump and alters the effect of digoxin. This would have important clinical relevance in cardiac complications related to type I and II diabetes.

Autoantibodies against serotoninergic 5-HT(4) receptor in patients with heart failure.

Serotoninergic 5-HT(4) receptors have been detected in several tissues including the heart. An autoimmune mechanism may underline the pathogenesis of heart failure. The aim of this work was to look for autoantibodies to the 5-HT(4) receptor in patients with heart failure. We looked for the presence of autoantibodies against 5-HT(4) receptor as well as angiotensin II type (AT1), ß(1)-adrenoceptor, and muscarinic M2 receptors in the sera of 176 patients with heart failure (female: n=96, male: n=80) and in 108 controls (female: n=69; male: n=39). The prevalence of 5-HT(4) receptor autoantibodies was 18.8% (n=33) in the group of patients with heart failure and 4.6% (n=5) in the control group (p<0.002). The prevalence of autoantibodies against AT1 was 1.7 (n=3), ß(1)-adrenoreceptor 0.6 (n=1), and muscarinic-receptor M2 4.2 (n=5). Female patients with diabetes and heart failure had a positive trend (p=0.07) to the presence of 5-HT(4) receptor autoantibodies. In the group of female heart failure patients we found a significant correlation with the presence of coronary heart disease (p=0.05). The clinical relevance of 5-HT(4) receptor autoantibodies has to be further studied. The prevalence of 5-HT(4) receptor autoantibodies was highly significant in patients with chronic heart failure. It was also a significant correlation between these autoantibodies and the female subgroup with coronary heart disease. It is conceivable that the increased prevalence of autoantibodies against the 5-HT(4) receptor in patients with heart failure is more than just an epiphenomenon.

Weight loss and severe jaundice in a patient with hyperthyroidism.

BACKGROUND: Thyrotoxicosis may significantly alter hepatic function and is associated with autoimmune disorders of the liver. CASE REPORT: We report the case of a thyrotoxic patient with Graves' disease and histologically established cholestatic hepatitis. Medical treatment of hyperthyroidism normalized liver function tests. CONCLUSIONS: In patients with elevated liver function parameters and jaundice of unknown origin, thyroid function should generally be tested. Moreover, medical treatment of hyperthyroidism with thyrostatics may cause severe hepatitis whereas untreated hyperthyroid patients are at risk of developing chronic liver failure.

[A patient with chronic diarrhoe, head pigmentation and alopecia. Cronkhite-Canada syndrome]. / Patient mit chronischer Diarrhoe, Pigmentierungsstörung und Haarausfall. Cronkhite-Canada Syndrom.

HISTORY AND FINDINGS ON ADMISSION: A 70-year-old man with a 14 month history of chronic severe diarrhea treated with budenosid and mesalazin was admitted because of peripheral oedema and weight loss of about 26 kg. INVESTIGATIONS AND DIAGNOSIS: A general pigmentation of the skin, especially on scull and hands, as well as dystrophic nail changes and alopecia of scalp and facial hair were seen. The tests showed a slight macrocytotic, normochromic anemia. Total protein and the clotting factors were decreased. Endoscopy revealed multiple sessile polyps in the stomach and duodenum in appearance to colon and rectum. Endoscopic removal of a polyp showed histologically cystic dilatation of foveolae and oedematous mucosa. The histological features, the wide distribution of the polyps together with the skin changes, lead to the diagnosis of Cronkhite-Canada syndrome (CCS). TREATMENT AND COURSE: The patient was initially treated with prednisolon 60 mg/d i. v. for 2 weeks, resulting in a marked improvement of symptoms and weight gain. He is at present in good health under prednisolon 20 mg/d per os and is followed up in our outpatient department. CONCLUSION: CCS is in up to 14 % of the cases associated with a carcinoma of the gastrointestinal tract. At present there are only reports about a successful treatment by steroids, prophylactic gastrectomy and proctocolectomy. Typical myopathic lesions of CCS have not been described to date, but the demonstrated improvement of creatinin kinase with successful treatment suggests a common pathophysiological mechanism.

[Portal vein hypertension during azathioprine therapy in patients with Crohn's disease--a frequent phenomenon?]. / Portale Hypertension unter Azathioprin bei Morbus Crohn--ein häufiges Phänomen?

HISTORY AND FINDINGS ON ADMISSION: A 45-year-old man with 18 years history of Crohn's disease who was on treatment with azathioprine (AZA) for the past 48 months was admitted because of haematemesis and melaena. INVESTIGATIONS AND DIAGNOSIS: Tests showed a slight elevation of bilirubin and a low platelet count. Endoscopy revealed esophageal and gastric fundus varices. Magnetic resonance imaging (MRI) revealed severe portal vein hypertension with a spleen-kidney convolute of varices. Liver biopsy showed hyperplasia of hepatocytes and a reticular fibrosis, consistent with the diagnosis of nodular regenerative hyperplasia (NRH). TREATMENT AND COURSE: AZA treatment was stopped. The fundal varices were treated with endoscopic histoacryl injection. The patient is at present in good health and is followed up in our outpatient department. CONCLUSION: AZA as a widely used immunosuppressive drug has side effects in about 5 - 10 % of the cases. The risk of hepatotoxicity in patients treated with AZA is often underestimated. Therefore, physicians treating patients with inflammatory bowel disease have to be precocious regarding the increase of hepatic enzymes and pathologic signs in liver imaging in relation of AZA treatment. The latter might refer to NRH which would lead to severe portal vein hypertension.

[Rapidly progressing cyst of the pancreas as a manifestation of an undifferentiated pancreatic carcinoma with osteoclastic giant cells]. / Rasch progrediente Pankreaskopfzyste als Manifestation eines undifferenzierten Pankreaskarzinoms mit osteoklastären Riesenzellen.

HISTORY AND FINDINGS ON ADMISSION: A 62-year-old woman presented with acute abdominal pain. INVESTIGATIONS AND DIAGNOSIS: Examination revealed a 3 cm large cyst of the pancreatic head accompanied by an acute pancreatitis. TREATMENT AND COURSE: The cystic mass showed rapid increase. After explorative laparatomy a pancreaticoduodenectomy was performed. Pathologic examination revealed an undifferentiated carcinoma with osteoclast-like giant cells. The tumor grew rapidly and the patient died 10 weeks after admission. CONCLUSIONS: An undifferentiated carcinoma with osteoclast-like giant-cells is a very rare cystic tumor of the pancreas. An accurate preoperative diagnosis of cystic tumors is only achieved in about 30 percent. Therefore, surgical exploration should be considered for all cystic neoplasms and cystic tumors that are not clearly defined.

[A 63 year old Turkish woman with recurrent pneumonia]. / 63-jährige Türkin mit rezidivierenden Pneumonien.

The differential diagnosis of a sinubronchial syndrome includes cystic fibrosis, allergic bronchopulmonic aspergillosis, Kartagener's syndrome, hypogammaglobulinemia and bronchioli-associated processes. The latter include cryptogenic organising pneumonia, constrictive bronchiolitis obliterans as well as the respiratory bronchiolitis. Our case presented a persistent interstitial shadow in the x-rax of the thorax and a relevant, mixed ventilation disturbance in lung function. A surgically performed lung biopsy finally allowed the diagnosis of diffuse panbronchiolitis, which is seldom found in central Europe. This disease is of unknown etiology and responds to long-term macrolide therapy.

Ghrelin/Leptin-imbalance in patients with primary biliary cirrhosis.

BACKGROUND: The recently discovered peptide hormone ghrelin mainly produced in gastric oxyntic cells may act as a counterpart to leptin in the regulation of food intake and fat utilization. Leptin, involved in the stimulation of proinflammatory cytokines and catabolic energy balance, is elevated in patients with liver cirrhosis. In the present study, we evaluated serum ghrelin and bound leptin levels in patients with primary biliary cirrhosis (PBC) in relation to C-peptide and glucose concentration. METHODS: In 22 female patients with PBC (Child-Pugh stage A) and in 36 female controls we measured serum ghrelin, bound leptin, and C-peptide levels using specific immunoassays. RESULTS: In comparison to controls serum bound leptin levels were significantly higher in patients with PBC ( p < 0.01) whereas serum ghrelin levels were decreased compared to the control group ( p < 0.01). In parallel, C-peptide concentrations were increased ( p < 0.01) with no significant change in circulating glucose levels. CONCLUSION: Our data confirm in PBC patients that serum bound leptin levels are increased and clearly show a parallel decrease in serum ghrelin concentrations acting as a physiological counterpart to leptin. Furthermore, we suggest that these changes are linked to the insulin resistance observed in our patients.

[Haematemesis and dysphagia in a 20-year-old woman with congenital spine malformation and situs inversus partialis]. / Hämatemesis und Dysphagie bei 20 Jahre alter Frau mit kongenitalem kaudalen Regressionssyndrom und Situs inversus partialis.

A 20-year-old woman with a four-week history of dysphagia, weight loss of four kilograms and unspecific abdominal pain was admitted because of sudden haematemesis. The physical examination showed a patient with a prominent kyphoskoliosis. The patient reported of having a situs inversus abdominalis and a tethered cord syndrome. Bladder function disorders were present since childhood. Upper endoscopy demonstrated a 4 cm large, exophytically growing necrotic tumour of the oesophagus. The CT scan showed a space occupying tumour of the oesophagus and metastases in a size of 1.5 cm in both lungs. Further imaging revealed a UICC-Stadium IVB (T2NxMIb ). Histology of the tumour biopsies showed a poor differentiated squamous cell carcinoma. Staging after the 6 th dose cisplatin (100 mg/m2/die) and 5-fluorouracil (5 x 1000 mg/m2/die) showed a mild reduction of the tumour and the metastases. The patient died ten months later of multiorgan failure after severe progress of tumour and metastatic growth. The manifestation of squamous cell carcinoma of the oesophagus is unusual in people at the age of twenty. Genetic and chromosomal analysis of the patient gave no evidence for a hereditary disorder. Drug history revealed that the patient had been treated with the alpha-receptor blocking drug phenoxybenzamine over at least 12 years for bladder dysfunction. Animal experiments of rats with exposition of phenoxybenzamine over 24 months produced gastrointestinal malignomas. By the German admission board phenoxybenzamine is only recommended for short term therapy. It seems to be likely that even in humans phenoxybenzamine acts as a mutagenic substance and should be carefully used in long-term treatment.

Leptin mediates a proliferative response in human gastric mucosa cells with functional receptor.

BACKGROUND: Recently, the rat stomach was reported as a source of leptin, a hormone mainly secreted by adipocytes. Also Helicobacter pylori-induced gastritis in humans was associated with locally elevated leptin levels. In addition, it was suggested that gastric leptin adjusts the function of the intestinal tract in parallel to the function of hypothalamic satiety centers. AIMS: Here we examined the synthesis and potential physiologic role of leptin in the human stomach. METHODS: RT-PCR was employed to detect leptin mRNA in the human stomach and the human gastric carcinoma cell line AGS while immunogold staining and electron microscopy were used to detect leptin protein. The in vitro effects of leptin on cell proliferation were examined in the AGS cell line. RESULTS: No leptin mRNA could be detected by RT-PCR, yet immunogold labeling and electron microscopy allowed visualization of leptin protein in the human gastric mucosa. At concentrations of 100 nM, leptin led to a significantly increased BrdU-uptake in AGS cells (+27%, p < 0.017). The MAP-kinase-1-specific inhibitor U0126 blocked the leptin-induced cell proliferation in a dose-dependent fashion. CONCLUSIONS: Leptin protein may not be produced but rather stored in human gastric cells. Leptin-induced increases in the proliferation of gastric mucosa cells suggests that leptin might contribute to mucosal integrity and gastroprotection.

[Secondary high-grade MALT lymphoma of the stomach in a 69-year-old patient with gastrocolic fistula]. / Sekundär hoch malignes MALT-Lymphom des Magens bei einem 69-jährigen Patienten mit gastrokolischer Fistel.

A 69-year-old man was referred to our department with an exorbitant foetor ex ore, dysphagia and dyspepsia. Upper endoscopy had been performed prior by an outpatient gastroenterologist and the patient had received an eradication therapy for a Helicobacter pylori-induced gastritis. At admission upper endoscopy showed a gastric ulcer which drained a stinking fluid. Endosonography, computed tomography and an upper gastrointestinal series with water soluble media revealed a gastrocolic fistula. Multiple biopsies showed a low-grade gastric MALT lymphoma. Therefore, a surgical reconstruction with Roux-en-Y esophagojejunostomy and transverso-descendostomy was performed. The histology of the completely removed stomach revealed a high-grade Non Hodgkin Lymphoma (NHL) with parts of a low-grade NHL. 3 weeks after surgery chemotherapy was started with the CHOP-regime which was well-tolerated by the patient.

[Symptomatic cyst of the pancreas and asymptomatic bilateral phaeochromocytoma]

Symptomatic cyst of the pancreas and asymptomatic bilateral phaeochromocytoma. HISTORY AND CLINICAL FINDINGS: A 39-year-old woman was admitted to our department of gastroenterology with recurrent epigastrical pain. Ten years previously the diagnosis of von Hippel-Lindau (VHL)-syndrome has been established. Two years before a germ line mutation in exon 3 of the VHL-tumour suppressor gene has been detected. The patient has a healthy son with a normal VHL-gene and four healthy siblings who had refused a genetic blood test. INVESTIGATIONS: At abdominal ultrasound at the head of the pancreas three 4 2 cm large cysts and in the region of the left adrenal gland a 2,9 2,7 cm large tumor were visible. MRI of the abdomen revealed in addition a 2,2 1,5 cm large tumour of the right adrenal gland. An asymptomatic biadrenal phaeochromocytoma was detected by elevated urine catecholamines and 123I-MIBG-scintigraphy. TREATMENT AND COURSE: The cysts of the pancreas were punctured under endosonographical control and analysis of the cyst fluid was not suspicious of a malignant cystic tumour. The patient had no further abdominal complaints. After oral treatment with the alpha-blocker phentolamine the biadrenal phaeochromocytoma was treated by retroperitoneal laparoscopic surgery in an organ-sparing fashion. Postoperatively ACTH-stimulating test revealed a normal cortisol response. CONCLUSION: Adrenocortical function can be preserved by la-paroscopic adrenal-sparing surgery in bilateral phaeochromocytoma.

Apoptosis and cell proliferation in the metaplasia-dysplasia-carcinoma-sequence of Barrett's esophagus.

BACKGROUND/AIMS: The regulation of apoptosis as a distinctive form of cell death and proliferation in the process of carcinogenesis in Barrett's esophagus is poorly understood. To investigate regulation of apoptosis, proliferation and the participation of the tumor suppressor gene p53, we examined these parameters in Barrett's metaplasia, dysplasia, and adenocarcinoma. METHODOLOGY: Apoptotic cells were identified and quantified in tissue specimens of 45 patients with different stages of Barrett's esophagus and normal fundus epithelium, respectively, using the in situ end-labeling and electron microscopy method in combination with morphological criteria. The tumor suppressor gene p53 was examined by direct sequencing of exon 4-8 as well as immunohistochemically. The proliferative activity was assessed by Ki67 immunostaining. RESULTS: Apoptotic cell death, identified by the in situ end-labeling and ultrastructural technique was significantly increased in Barrett's epithelium with intestinal metaplasia than in specimens with normal fundic epithelium and Barrett's carcinomas (P < 0.01). The proliferative activity, defined as Ki67 labeling index, was highest in adenocarcinomas (P < 0.01). P53 mutations were found in 8/9 adenocarcinomas and 2/5 specimens with dysplasia. Apoptosis was lower in p53 positive specimens of the metaplasia-dysplasia-carcinoma-sequence than in p53 negative specimens of Barrett's esophagus (P < 0.05). CONCLUSIONS: The higher levels of both apoptosis and proliferation indicate an increased cell turnover in Barrett's epithelium. Apoptosis seems to maintain tissue homeostasis, which is regulated by p53, and gradually lost in the metaplasia-dysplasia-carcinoma-sequence of Barrett's esophagus.

Diabetes insipidus in a patient with a highly malignant B-cell lymphoma and stomatitis.

A 37-year-old male patient with a diffuse pleomorphic B-cell-lymphoma, which has been diagnosed two month earlier with the primary site at the pterygopalatine fossa on both sides with infiltration of the clivus and cavernous sinus was referred to our hospital for continuation of the third course of CHOP chemotherapy. At admission he reported about a recent history of painful swallowing and intermittent substernal chest pain. Alleviation of the pain on swallowing and the chest pain was apparently only possible by drinking 10 to 15 l of cold coca cola throughout the day and night, a regimen that resulted in polyuria. Physical examination revealed extensive thrush stomatitis and soor esophagitis. Despite successful treatment with fluconazole, polydipsia continued unabated. The classic osmotic test of dehydration and exogenous vasopressin revealed hypothalamic diabetes insipidus (DI). Basal hormones and stimulated endocrine function tests of the adenohypophysis were found to be normal. MRI-scan revealed lymphoma infiltration of the neurohypophysis. After the third course of CHOP chemotherapy the patient surprisingly recovered completely from his excessive thirst. The present report shows that clinical disorders such as thrush stomatitis can mask diabetes insipidus caused by an early relapsing lymphoma.

Frequency of TPR-MET rearrangement in patients with gastric carcinoma and in first-degree relatives.

BACKGROUND: The activation of the c-met protooncogene through a rearrangement has been detected previously in gastric carcinoma tissue and precancerous lesions. In the current study the authors analyzed the rearrangement of TPR-MET in gastric carcinoma patients and in first-degree relatives to evaluate the potential role and timepoint of this genetic alteration in the process of gastric carcinogenesis and its potential value in identifying those individuals with an increased risk of developing gastric carcinoma. METHODS: The presence of TPR-MET mRNA was determined in gastric tissue from 19 patients with gastric carcinoma and in the gastric mucosa of 18 first-degree relatives without gastric carcinoma and in the gastric mucosa of 18 first-degree relatives without gastric carcinoma using a nested reverse transcriptase-polymerase chain reaction (RT-PCR) and Southern blot analysis. A 205-base pair (bp) cDNA fragment and a 70-bp cDNA fragment spanning the breakpoint were amplified by nested PCR. Amplification products were hybridized with an oligonucleotide labeled at the 3'-end with DIG-11-dUTP spanning the breakpoint using Southern blot analysis. The MNNG-HOS cell line served as a positive control. RESULTS: TPR-MET mRNA was detected in nine gastric carcinoma patients (47%). Among these patients, TPR-MET mRNA was present in the both tumor and tumor free tissues in 5 patients (26%), in the tumor tissue only in 2 patients (11%), and in the tumor free gastric mucosa only in 2 patients (11%). It is interesting to note that TPR-MET rearrangement also was detected in the gastric corpus mucosa of 1 first-degree relative (6%), but in none of the control subjects. CONCLUSIONS: The data from the current study indicate that TPR-MET activation may be an early event in gastric carcinogenesis and may be useful for the identification of individuals with an increased risk of developing gastric carcinoma.

Leptin and its receptor in normal human gastric mucosa and in Helicobacter pylori-associated gastritis.

BACKGROUND: Leptin, a newly discovered weight-reducing hormone, is mainly produced in fat cells. Recently, this hormone has been reported to be produced in rat gastric mucosa cells. In the present study we analyzed the localization and expression of leptin and its receptors in normal human gastric mucosa and in patients with Helicobacter pylori-associated gastritis. METHODS: Plasma leptin levels and gastric mucosa leptin content were determined in 39 patients with dyspepsia. Cellular localization of leptin and of the signaling receptor (Ob-RL) were assessed by immunohistochemistry. Reverse transcriptase polymerase chain reaction (RT-PCR) for leptin receptor isoforms was performed on gastric epithelial cells isolated by laser-capture-microdissection. RESULTS: Leptin content of the corpus gastric mucosa in H. pylori-positive patients was significantly increased (4.6+/-1.2. n = 15) as compared with the H. pylori-negative group (27.5+/-0.5 pg/mg, n = 24, P = 0.006). The presence of leptin immunoreactivity was shown in the lower half of corpus epithelial glands. By RT-PCR no leptin mRNA was detectable in human gastric tissue. In contrast, expression of both Ob-R(L) and the leptin receptor isoforms could be detected in gastric epithelial cells. Leptin receptor protein was detected throughout the mucosa. CONCLUSIONS: Leptin itself is stored and secreted but not produced in human gastric mucosa. The functional receptor and all isoforms are present in human gastric mucosa. H. pylori-associated gastritis leads to significant increases in local leptin concentration in the gastric corpus.

Relation of free and specifically bound leptin to insulin secretion in patients with impaired glucose tolerance (IGT).

Impaired glucose tolerance (IGT) is frequently associated with an increased fat mass and an altered fat distribution. The adipocyte derived hormone, leptin has been shown to interact with insulin at various levels and may be intimately involved in this process. However, only limited data concerning the interaction of insulin, glucose tolerance and leptin are available and no data exist on the potential influence of bound vs. free circulating leptin. We therefore studied free and bound leptin in 136 patients (77 males, 59 females) with IGT, in relation to plasma glucose, insulin, proinsulin and C-peptide levels as well as serum free and bound leptin concentrations during an oral glucose tolerance test (oGTT). The expected positive relation of free serum leptin levels with body mass index (BMI) was found. Free leptin concentrations were higher in women than in men. Analysis in tertiles revealed a significant relation between free leptin (16-58, 60-160, and 169-932 pmol/l) and mean fasting insulin levels (65, 93, and 100 pmol/l). This relationship remained significant in a multiple regression analysis with BMI and gender as covariates. Similar independent relationships to leptin serum levels were observed for HbA1c and plasma C peptide levels and the proinsulin/insulin ratio but not for plasma glucose and proinsulin levels. These data suggest a fine tuning of leptin by small changes in circulating insulin levels observed in impaired glucose tolerance.