Coronary flow reserve, insulin resistance and blood pressure response to standing in patients with normoglycaemia: is there a relationship?

AIMS

To establish the relationships between coronary flow reserve, cardiovascular autonomic function, and insulin resistance characterized by the homeostasis model assessment insulin resistance score in patients with normal carbohydrate metabolism according to the World Health Organization (WHO) and American Diabetes Association (ADA) criteria, and with morphologically normal epicardial coronary arteries.

METHODS

Twenty-five patients [12 women and 13 men, mean (sd) age: 53 +/- 11 years] with normal coronary angiography were enrolled into the study. Coronary flow reserve was measured during stress transoesophageal echocardiography. Autonomic dysfunction was assessed by means of five standard cardiovascular reflex tests. The fasting serum glucose and insulin levels were determined and the homeostasis assessment model insulin resistance score was calculated.

RESULTS

In patients with normal carbohydrate metabolism, negative correlations were observed between the coronary flow reserve and both the serum insulin level (r = -0.445, P = 0.026) and the homeostasis assessment model insulin resistance score (r = -0.449, P = 0.024). The systolic blood pressure response to standing also correlated with the coronary flow reserve (r = -0.519, P = 0.011). The heart rate response to deep breathing, the Valsalva ratio, the 30/15 ratio and the sustained handgrip test results were not correlated with the coronary flow reserve.

CONCLUSIONS

Our data suggest the possible role of insulin resistance and early sympathetic nerve dysfunction in the development of decreased coronary flow reserve in patients without diabetes mellitus or impaired glucose tolerance.

Regional Differences in the Manifestation of Gastrointestinal Motor Disorders in Type 1 Diabetic Patients with Autonomic Neuropathy

OBJECTIVE

The aim of this work was to establish the prevalence and severity of different gastrointestinal symptoms and their relationships to esophageal, gastric and recto-anal motor disturbances by manometry in patients with Type 1 diabetes mellitus and autonomic neuropathy.

PATIENTS AND METHODS

Sixteen patients (mean age: 53.4 +/- 14.9 years) with long standing type 1 diabetes mellitus (mean diabetes duration: 22.1 +/- 14.7 years) and autonomic neuropathy (mean Ewing score: 5.73 +/- 2.34) were investigated. The gastrointestinal symptom scores were established by using the Talley dyspepsia questionnaire. The motor function of the digestive tract was tested in the esophagus, in the stomach, and in the ano-rectum by perfusion manometry.

RESULTS

Manometric evaluation of the esophagus did not reveal significant abnormalities in the region of the upper sphincter in patients with diabetes mellitus. In contrast, diabetic patients had decreased peristaltic wave amplitude, prolonged duration, decreased wave propagation velocity, and increased number of simultaneous contractions in the esophageal body, and decreased lower esophageal sphincter pressures with prolonged relaxation compared to the age- and sex-matched controls. Symptom analysis showed correlations between reflux symptoms and LES relaxation times, and between dysphagia scores and esophageal body peristaltic wave duration, propagation velocity and the rate of simultaneous contractions. In the gastric antrum, frequent, and often severe, fasting motility disorders were observed, which had no correlation with dyspeptic symptoms. In the ano-rectal region the diabetic patients had a lower squeezing-resting pressure difference, and impaired fecal expulsive function. Motility disorders were simultaneously present at multiple parts of the gastrointestinal tract in 13/16 cases.

CONCLUSIONS

In patients with type 1 diabetes mellitus and autonomic neuropathy gastrointestinal motility disorders were observed frequently, and in most of the cases simultaneously. While esophageal and ano-rectal symptoms correlated better with the manometric abnormalities, the lack of correlation between the impaired fasting gastric motility and dyspeptic symptoms shows that, on the basis of the clinical symptom analysis, the prevalence of such motor disorders could be underestimated. The early recognition of gastrointestinal motility disorders may be important for the better long-term management of patients with type 1 diabetes mellitus.

Impaired accommodation of proximal stomach in patients with alcoholic liver cirrhosis

BACKGROUND

Impaired gastric emptying has previously been detected by ultrasonography in cirrhotic patients, and the role of the type of meal has also been discussed. While these earlier studies dealt with the distal part of the stomach, the aim of our study was to examine the effects of three different types of meal on the proximal stomach in cirrhotic patients.

METHODS

The proximal stomach was examined by ultrasonography in 15 healthy volunteers and in 21 alcoholic cirrhotic patients. The subjects received a liquid meal with a low calorie content and two different semisolid test meals with a low calorie content or high calorie and fat contents. The proximal gastric size was assessed by ultrasonography in a sagittal area and a frontal diameter. On the basis of assessment of the autonomic nervous function, the cirrhotic patients were divided into two groups: autonomic neuropathy positive and autonomic neuropathy negative.

RESULTS

The postcibal gastric size immediately after ingestion of the liquid test meal was significantly lower in the cirrhotic patients than in the healthy controls. In the healthy volunteers, the measures of the proximal gastric size were significantly higher than in either group of cirrhotic patients at to, and at 10, 20 or 30 min after ingestion of a semisolid test meal with low calorie and fat contents. The proximal gastric sizes in the three groups of investigated subjects did not differ when the meal with high fat and calorie contents was tested. When the liquid meal was administered, the proximal gastric size was significantly lower in the cirrhotic patients with autonomic neuropathy. A significant intragroup difference was not observed when the semisolid meals were tested.

CONCLUSIONS

This study reveals an impairment of the proximal stomach in alcoholic cirrhotic patients. The low calorie liquid meal distinguishes between the two groups of cirrhotic patients and healthy controls.

Gallbladder hypomotility in diabetic polyneuropathy

This study was performed to evaluate the gallbladder motility in long-standing diabetes mellitus. The gallbladder function of diabetic patients was measured by means of quantitative hepatobiliary scintigraphy, and the severity of the associated autonomic and sensory polyneuropathy was determined. The presence of a marked gallbladder hypomotility was established, and a positive correlation was observed between the severity of the autonomic disturbance and the contractile disorder. This study underlines the important role of the neuropathy in the development of gallbladder hypomotility accompanying long-term diabetes mellitus.

Brainstem auditory-evoked potential examinations in diabetic patients

Brainstem auditory-evoked potential (BAEP) examinations were performed in 15 patients with long-standing type-1 diabetes mellitus (DM). Cardiovascular reflex tests were applied for assessment of autonomic neuropathy. The aim of our investigation was to compare the BAEP results of this patient group with controls and to look for a possible correlation between the alteration of the auditory brainstem function and the cardiovascular autonomic neuropathy. Analysis of the latencies (waves I, II, III and V) and the inter-peak latencies (waves I-III and I-V) of BAEPs revealed a significant difference between diabetics and healthy controls. The amplitudes of waves I, III and V were definitely lower in comparison with those of healthy controls. A positive correlation was observed between the overall autonomic score and the latencies (waves III and V) and inter-peak latencies (waves I-III and I-V). These data support the hypothesis that long-standing DM and diabetic neuropathy might be related as a cause of certain dysfunctions of the central auditory pathways.

[Diagnosis of Verner-Morrison syndrome (VDHA) and its treatment with sandostatin an streptozocitin]

A case report is presented of a man with Verner-Morrison syndrome of extreme severity, caused by an unresectable pancreatic VIPoma. The pathological role of vasoactive intestinal polypeptide (VIP) is discussed in the pathogenesis of Watery Diarrhoea, Hypokalaemia, Achlorhydria (WDHA) syndrome. The authors describe the typical symptoms of the syndrome and provide a diagnostic and therapeutic strategy. Plasma level of VIP was determined by the authors' own VIP RIA method. Administration of a long acting somatostatin analogue, octreotide (Sandostatin, Sandoz) at a dose of 100 micrograms daily, decreased the plasma level of VIP from about 55 to 38 fmol/ml, which was associated with complete regression of the diarrhoea. Due to the 'escape phenomenon' the dose of Sandostatin was gradually increased and finally completed with streptozotocin (Zanosar, Upjohn) administration, which was repeated every 8 weeks. The combination of Sandostatin and streptozotocin resulted in complete regression of diarrhoea and substantial diminution of the tumour mass. The patient displayed a weight gain and returned to normal life.