Ventricular ectopic activity, left ventricular mass, hyperinsulinemia, and intracellular magnesium in normotensive patients with obesity.

Insulin resistance, a well-known feature of obesity, is associated with several pathological changes, which are potentially arrhythmogenic. Ventricular ectopic activity in normotensive obese patients has not been studied in detail. Therefore the authors designed a study to investigate potential relationships among ventricular ectopic activity, left ventricular mass, hyperinsulinemia, and intracellular magnesium concentration in obese patients. Thirty-two obese patients and 32 nonobese control subjects, who were referred to outpatient department because of ventricular ectopy, participated in the study. The groups were matched for age and gender. All had normal glucose tolerance. All subjects underwent a 75-g glucose tolerance test, and blood samples were obtained at 30, 60, and 120 minutes thereafter for determination of glucose and insulin concentrations. Echocardiography was performed and left ventricular mass index was calculated. The number of ventricular ectopic beats per hour (VEB/hour) was recorded by 24-hour ECG Holter monitoring. Plasma and erythrocyte magnesium concentrations were determined by atomic absorption spectrophotometer. Obese patients had higher body weight, body mass index, heart rate, and left ventricular mass index. Obese subjects had higher fasting insulin as well as insulin/glucose ratio and broader area under the curve of insulin (AUC-I) compared to nonobese subjects. Insulin sensitivity appeared to be lower in the obese group. Holter monitoring showed more VEB/hour in the obese group. Magnesium concentration in serum and in erythrocytes was lower in obese persons. In the obese group a positive correlation was found between left ventricular mass index and fasting insulin (r=0.345, p=0.027), insulin/glucose index (r=0.351, p=0.049), and AUC-I (r=0.405, p=0.011). The number of VEB/hour in obese patients was in positive correlation with age (r=0.681, p<0.001), left ventricular mass index (r=0.542, p=0.001), fasting insulin (r=0.380, p=0.016), and AUC-I (r=0.493, p=0.002) and in negative correlation with magnesium concentration in erythrocytes (r=-0.457, p=0.004). Multiple regression analysis showed that age and AUC-I are the only determinants of VEB/hour and together explained 56% of the variability in the obese subjects. It appears that in obese normotensive subjects, ventricular ectopic beats are related to age, insulin resistance, left ventricular mass index, and decreased intracellular magnesium content.

Are insulin metabolism and night-time blood pressure related to left ventricular hypertrophy?

Essential hypertensives in whom blood pressure does not fall during sleep (non-dippers) are thought to be at greater risk of cardiovascular morbidity. Insulin resistance is also suggested to be a risk factor for cardiovascular morbidity. The purpose of the present study was to evaluate the relationship of insulin metabolism to left ventricular hypertrophy in dippers and non-dippers. Thirty male, non-diabetic out-patients with newly diagnosed arterial hypertension were included in the study: 21 dippers (mean age 45+/-13 years; body mass index 28.2+/-4.0 kg/m2) and nine non-dippers (mean age 48+/-10 years, body mass index 28.6+/-3.9 kg/m2). Patients were subdivided into dippers and non-dippers on the basis of 24-h ambulatory blood pressure monitoring. Insulin and glucose responses to an oral glucose load have been evaluated. C-peptide levels were determined. Left ventricular mass was assessed by echocardiography. Non-dippers had significantly higher mean night-time systolic (non-dippers: 148+/-9; dippers: 123+/-16 mmHg; P<0.001), diastolic blood pressure (non-dippers: 90+/-8; dippers: 77+/-8 mmHg; P<0.001) and non-significantly higher left ventricular mass (279+/-92 g) and left ventricular mass index (135+/-46 g/m2). No significant difference was found between C-peptide, insulin, glucose levels and incremental areas between the two groups. Night-time blood pressure, insulin, C-peptide and glucose did not correlate with left ventricular mass in non-dippers. Dippers showed a positive correlation between fasting C-peptide and left ventricular mass (r=0.48, P=0.02) and between glucose and left ventricular mass (r=0.42, P=0.05). Our data indicate that night-time blood pressure and insulin are not related to left ventricular hypertrophy in patients with essential hypertension.

Diastolic function and insulin resistance in essential hypertension.

We studied the relationship of insulin metabolism to diastolic function in 41 hypertensive patients and 24 healthy subjects. They underwent a 75-g oral glucose tolerance test. Integrated response of insulin to the glucose load was calculated as the area under the curve of insulin (AUC-I) and glucose (AUC-G). The ratio AUC-I/AUC-G was taken as an index of insulin resistance. Echocardiographic examination was performed to measure left ventricular mass. We used pulsed Doppler technique to assess the ratio of early to late transmitral peak velocity (E/A). The hypertensives had higher fasting insulin concentrations, insulin levels at 60 min and at 120 min after oral glucose load. They had higher AUC-I and higher index of insulin resistance compared to normotensives. Patients with hypertension had a lower E/A ratio in comparison to normotensive volunteers. In all subjects, the E/A ratio was negatively correlated with fasting insulin and insulin concentrations at 30, at 60 and at 120 min, AUC-I and insulin resistance index. Multiple regression analysis was performed to evaluate the above relationships, when the effects of confounding factors such as age, heart rate and systolic blood pressure were taken into account. We found that E/A ratio is negatively correlated to insulin concentrations at 120 min and to AUC-I in hyperinsulinemic subgroup of subjects (fasting insulin> 10). We conclude, that insulin metabolism and E/A ratio, which reflects diastolic function of the left ventricle, are related in hypertension.

Filling a dialysis circuit with albumin does not prevent platelet activation during hemodialysis: in vivo study.

The aim of our prospective clinical study was to evaluate whether filling a dialysis circuit with albumin before hemodialysis (HD) can prevent platelet activation during the procedure. Eight patients with chronic HD participated in the study, each dialyzed first with albumin and a week later without it. All other parameters of the HD procedure were unchanged (cellulose acetate hollow fiber dialyzer, blood flow of 300 ml/min, and low dose heparin). Before HD with albumin, 6.7% human albumin in saline was recirculated in the dialysis circuit for 10 min at a flow rate of 100 ml/min, and infused into the patient. We found a significant increase in the beta-thromboglobulin levels during both procedures. We found no difference in plasma coagulation system activation measured by fibrinopeptide A concentration. Neither was there any difference in the macroscopic antithrombotic activity assessed at the end of HD by measuring the volume of clots in the arterial and venous bubble trap and by counting the number of clotted fibers in the dialyzer. It seemed that filling the dialysis circuit, which had a cellulose acetate dialyzer, with human albumin did not improve its thrombogenicity.

Sphincter of Oddi function studied by radioimmunoassay of biliary trypsin in patients with bile duct stones and in controls.

The trypsin level in bile was studied by radioimmunoassay in a prospective series of 63 patients with gallstone disease but without signs or symptoms of cholecystitis or pancreatitis in order to find indirect evidence of a retrograde flow of pancreatic juice. Mobile duct stones were present in 18 patients and impacted stones in 12. The remaining 33 patients had stones only in the gallbladder and served as controls. The average intraoperative trypsin level of the ductal bile was normal, both in the control group and in the group with stones occluding a potential retrograde reflux of pancreatic juice. After removal of the impacted stones, the bile showed a significantly higher trypsin level. The average intraoperative trypsin level for the group with mobile stones was significantly higher than that of the control group, and was further increased 10 days postoperatively. The trypsin level of ductal bile from 23 of the 30 patients (77%) with bile duct stones exceeded that of the 33 patients with stone-free bile ducts, indicating an inflow of pancreatic juice to the bile ducts of patients with bile duct stones. The present results correspond well to those in a previous report on retrograde phasic contractions of the sphincter of Oddi in the majority of patients with bile duct stones. This dysfunction of the sphincter, which persisted for 10 days after surgical stone removal, may be the primary disorder, probably consisting of a retrograde propulsive activity of the sphincter of Oddi.

In vitro fertilization and embryo transfer programme in Ljubljana.

Results of the IVF-ET programme from June 1983 to July 1984 are presented. The procedure was performed in 98 women in 127 cycles. Six normally ongoing clinical pregnancies, three early spontaneous abortions and six biochemical pregnancies were achieved. The laparoscopic techniques of oocyte retrieval were used. Ovulation was first stimulated by clomiphene citrate and later on by gonadotropins only. Comparison of these two regimens showed gonadotropin stimulation to be more effective than clomiphene stimulation, considering the respective transfer rate of 73.3% (gonadotropins) and 18.8% (clomiphene).