Comparative efficacy study of atorvastatin vs simvastatin, pravastatin, lovastatin and placebo in type 2 diabetic patients with hypercholesterolaemia

Although there is little information from primary or secondary prevention trials on cholesterol-lowering medication in diabetic patients, the reduction of elevated cholesterol is widely recommended for this group. The American Diabetes Association (ADA) recommends drug therapy in diabetic patients if low density lipoprotein (LDL)-cholesterol remains at > 130 mg/dl, or > 100 mg/dl in patients with macroangiopathy, after dietary intervention. When cholesterollowering medication is indicated, the choice of the drug must take into account the other lipid abnormalities that are often present and the need to maintain optimal glycaemic control. In the present study we compared the efficacy and safety of the novel HMG-CoA reductase inhibitor atorvastatin at the dose of 10 mg/day with simvastatin , lovastatin and pravastatin at doses of 10, 20 and 20 mg/day, respectively, and placebo, in type 2 diabetic patients with moderate elevation of LDL-cholesterol with or without elevation of triglycerides. All the quoted agents are enzyme inhibitors effective in lowering LDL-cholesterol in humans. The efficacy endpoints were the mean per cent changes in plasma LDL-cholesterol (primary), total cholesterol, triglycerides, and high-density lipoprotein (HDL)-cholesterol concentrations from baseline to the end of treatment (24 weeks). Atorvastatin at a dose of 10 mg/day produced: (1) a significant reduction in LDL-cholesterol (-37%) in comparison with equivalent doses of simvastatin (-26%), pravastatin (-23%), lovastatin (-21%), and placebo (-1%); (2) HDL-cholesterol increases (7.4%) comparable to or greater than those obtained with simvastatin (7.1%), pravastatin (3.2%), lovastatin (7.21%), and placebo (-0.5%); (3) a significantly greater reduction in total cholesterol (- 29%) than that obtained with simvastatin (-21%), pravastain (-16%), lovastatin (-18%), and placebo (1%); and (4) a significantly greater reduction in triglycerides than that obtained with all the other drugs and placebo. In all treatment groups no significant variation in fibrinogen concentration was observed. All reductase inhibitors studied had similar levels of tolerance. There were no incidents of persistent elevations of serum aminotransferases or myositis.

Effects of insulin-glucose infusion on left ventricular function at rest and during dynamic exercise in healthy subjects and noninsulin dependent diabetic patients: a radionuclide ventriculographic study

OBJECTIVES

The aim of this study was to evaluate: 1) the effects of insulin administration on left ventricular ejection fraction (LVEF) during exercise, and 2) the eventual impairment of the cardiovascular response to insulin in noninsulin dependent diabetes mellitus.

BACKGROUND

Insulin influences the cardiovascular system, but its effect on left ventricular function has yet to be established.

METHODS

The effects of normal saline (test A) and insulin-glucose (insulin = 1.7 mU x kg(-1) x min(-1); glucose = 6 mg x kg(-1)min(-1)) (test B) infusions on systolic and diastolic functions at rest and during dynamic exercise were examined by radionuclide ventriculography. Twenty-two noninsulin-dependent diabetic patients and 22 gender, age and body mass index matched healthy subjects were investigated.

RESULTS

Both groups had normal scintigraphic parameters at rest and during dynamic exercise. Rest- and stress-LVEF as well as rest- and stress-peak filling rate were significantly (p < 0.001) lower in diabetic than in healthy subjects, both in test A and B. Rest-LVEF was significantly higher during test B than it was in test A only in diabetic subjects (p < 0.01). Stress-LVEF was significantly higher (p < 0.05) during test B than it was in test A, in both groups. Insulin-glucose infusion did not modify rest- and stress-peak filling rate in either group. No difference in left ventricular end diastolic volume and in mean blood pressure was found between test A and B at rest and during exercise in either group. A significant linear correlation between LVEF and the index of insulin sensitivity was found in diabetic patients.

CONCLUSIONS

In both normal and diabetic humans, insulin induces a very important rise in LVEF after submaximal work. However, the rise is significantly lower in diabetic than in nondiabetic subjects. The increase in exercise-LVEF on insulin is likely due to an enhancement of ventricular contractility. Insulin resistance could justify the lower angioscintigraphic indexes in diabetic subjects.

Natural history of hepatitis C virus carriers with persistently normal aminotransferase levels

BACKGROUND & AIMS

Some patients with serum hepatitis C virus (HCV) have persistently normal aminotransferase (ALT) levels and are affected by cirrhosis. This study prospectively evaluated progression of the disease in a group of anti-HCV-positive patients with persistently normal ALT levels.

METHODS

Thirty-seven subjects were studied. Each subject underwent liver biopsy at baseline and after 5 years of follow-up. At baseline, serum samples were tested for genotypes and HCV RNA load. ALT levels and serum HCV RNA were tested every other month and every 6 months, respectively. Patients with increased ALT were discharged from the study and treated with IFN. Five years after the end of IFN therapy, a liver biopsy was performed.

RESULTS

Liver biopsy at baseline showed chronic hepatitis in 34 patients and normal histology in 3 patients, 2 of whom were negative for HCV RNA and 1 positive. HCV genotypes were distributed as follows: 2a, 56%; 1b, 41%; and 1a, 3%. At the end of 7-year follow-up, 73% of the patients still had normal ALT values. Liver histology after 5 years was comparable to that observed at entry to study.

CONCLUSIONS

Most patients with persistently normal ALT serum levels have very mild chronic hepatitis. However, healthy anti-HCV-positive subjects exist. In patients with HCV-related chronic hepatitis associated with persistently normal ALT levels, the grade of disease activity does not increase over years and progression to cirrhosis is slow or absent.

Cochlear dysfunction in type 2 diabetes: a complication independent of neuropathy and acute hyperglycemia

The effects of type 2 diabetes on evoked otoacoustic emissions (e-OAEs) elicited by clicks in subjects with normal hearing and the involvement of the central (CNS) and peripheral nervous system and acute hyperglycemia were investigated. In study 1, 110 type 2 diabetic patients and 106 control subjects matched for age and gender were investigated by e-OAEs. Central and peripheral neuropathy were evaluated respectively by auditory brainstem responses (ABRs) and according to San Antonio Consensus Conference criteria. In study 2, 10 healthy and 10 type 2 diabetic men matched for age, all with normal e-OAEs, underwent a 5-hour hyperglycemic clamp study. e-OAE tests were performed before and during the hyperglycemic clamp. In study 1, e-OAEs were impaired in 51.8% (57 of 110) of the diabetic subjects, in comparison to 4.7% (five of 106) of the control group (P < .0001). Diabetics with impaired e-OAEs (e-OAEs-), in comparison to those with normal e-OAEs (e-OAEs+), were older (51.0+/-5.8 v 45.1+/-6.0 years, P < .001), had diabetes longer (11.5+/-4.4 v 7.0+/-3.9 years, P < .001), achieved poorer metabolic control as judged by hemoglobin A1c ([HbA1c] 6.9%+/-0.4% v 6.5%+/-0.3%, P < .001), and had more peripheral neuropathy (46% v 23%, P < .02). No difference was observed between e-OAEs- and e-OAEs+ subjects for retinopathy or nephropathy. Nevertheless, when the duration of diabetes was corrected by multiple regression analysis, the correlation between sensorineural damage and peripheral neuropathy lost significance (P = .12). Diabetic groups (e-OAEs+ and e-OAEs-) showed greater latency in waves I, III, and V and greater interwave latency for waves I to V than the control group, but there was no significant difference in ABRs between e-OAEs+ and e-OAEs- subjects. In study 2, there were no significant changes in e-OAE intensities compared with basal values during the entire hyperglycemic clamp in either type 2 diabetic or control subjects. No difference was observed between the two groups at each time of the clamp. Thus, type 2 diabetic subjects show a higher rate of compromised e-OAEs than healthy individuals. The e-OAE dysfunction does not associate with either an injury to the auditory nervous pathway or diabetic microvasculopathy. The apparent interference of peripheral neuropathy in e-OAEs loses significance when corrected for the duration of diabetes.

Short- and long-term treatments with iloprost in diabetic patients with peripheral vascular disease: effects on the cardiovascular risk factor plasminogen activator inhibitor type-1

OBJECTIVES

Iloprost, an analogue of prostacyclin, is often utilised in subjects with diabetes mellitus complicated by macroangiopathy.

METHODS

The effects of iloprost infusion on plasminogen activator inhibitor type-1 (PAI-1), glucometabolic control and cardiovascular equilibrium in patients with type-2 diabetes mellitus and peripheral arterial occlusive disease were investigated. Thirteen (7 men/6 women) normal-weight, normotensive and non-smoker type-2 diabetic patients (63.8 +/- 3.4 years, mean +/- SD) with peripheral arterial occlusive disease, stage-II according to Fontaine classification, were enrolled. Eight (four men/four women) patients underwent three study designs, each separated by a 1-week interval: study I, infusion of iloprost (3 ng kg(-1) min(-1) for 5 h) for 1 day alone (short-term treatment); study II, infusion of saline (for 5 h) for 1 day (control treatment); study III, infusion of iloprost (3 ng kg(-1) min(-1) for 5 h) over a period of 28 days (long-term treatment). The remaining five (three men/two women) patients underwent study IV only, infusion of saline over a period of 28 days (placebo treatment). Plasma levels of glucose, plasminogen, PAI-1 activity and fibrinogen, blood pressure and heart rate were determined in all studies, while plasma insulin levels, blood HbA(1c), walking distance and Winsor index only in studies III and IV.

RESULTS

Both short- and long-term treatments with iloprost significantly reduced PAI-1 activity (baseline vs end: 17.4 +/- 1.9 AU/ml vs 15.0 +/- 1.6 AU/ml, P < 0.02; 20.5 +/- 7.6 AU/ml vs 7.9 +/- 2.1 AU/ml, P < 0.002, respectively). Long-term treatment with iloprost significantly increased walking distance (baseline vs end: 325 +/- 41 m vs 496 +/- 52 m, P < 0.0001), but not Winsor index. Neither glucometabolic control nor cardiovascular equilibrium were affected by short- and long-term treatments with iloprost. Control and placebo treatments did not cause any significant modifications in the parameters evaluated.

CONCLUSION

If confirmed by further investigations, the results of this pilot study suggest that iloprost, infused for both brief and long periods, is able to reduce the cardiovascular risk factor PAI-1, increases free walking capacity and does not affect glucometabolic control and blood pressure in type-2 diabetic patients complicated by macroangiopathy.

[Non-insulin-dependent diabetes mellitus associated with nonalcoholic liver cirrhosis: an evaluation of treatment with the intestinal alpha-glucosidase inhibitor acarbose]

Non-insulin-dependent diabetes mellitus not responding to diet only in patients with non-alcoholic liver cirrhosis is characterized by high post-prandial hyperglycemia. The aim of this study was to evaluate the safety and efficacy of 24 weeks of treatment with 300 mg acarbose per day in 76 consecutive outpatients affected by type 2 diabetes and well-compensated liver cirrhosis. The study design was double-blind cross-over vs placebo. All patients tolerated both treatments well, and no significant variations in liver function tests were observed (< 5% vs pre-treatment). A significant reduction of several parameters was observed only after acarbose: fasting glycemia (19 +/- 6 vs 2 +/- 0.5%; p < 0.01), post-prandial glycemia (41 +/- 9 vs 3 +/- 0.6%; p < 0.01), mean glycemia (30 +/- 8 vs 14 +/- 5%; p < 0.01), daily glycemic variation (52 +/- 8 vs 8 +/- 1%; p < 0.01), HbA1c (16 +/- 1 vs 2 +/- 0.5; p < 0.05), incremental area of C-peptide after a standard meal (80 +/- 19 vs 200 +/- 36 ng/mL/300 min; p < 0.01). After acarbose a significant increase of intestinal voiding/week (98 vs 28%; p < 0.01) and a parallel reduction of blood ammonia levels (52 +/- 9 vs 9 +/- 5%; p < 0.01) were observed. Results clearly document the good tolerability and the absence of toxic effects of acarbose on the liver, due to a theoretic absence of both absorption by the gut and hepatic metabolism of the drug. In fact, acarbose increases peristaltic movement of the gut, stimulates the proliferation of saccharolytic bacteria and simultaneously reduces proteolytic bacterial proliferation, thus actively reducing blood ammonia levels. These unexpected effects of acarbose may be used to advantage for the treatment of type 2 diabetes mellitus in patients with well-compensated liver cirrhosis.

The role of autonomic neuropathy as a risk factor of Helicobacter pylori infection in dyspeptic patients with type 2 diabetes mellitus

A high prevalence of upper gastrointestinal symptoms is described in diabetic patients and, at least in part, this has been attributed to abnormal emptying of the stomach. In an unselected small series of dyspeptic patients with Type 2 diabetes mellitus (DM2), we previously described a higher prevalence of Helicobacter pylori (Hp) infection associated with autonomic neuropathy (AN) than in non-diabetic subjects. To evaluate the prevalence of Hp and its relationship with AN, we studied 164 DM2 patients, matched for sex, age ( +/- 5 years) and body weight ( +/- kg) to 164 non-diabetic subjects, all affected with dyspepsia of unknown origin. Results document that the prevalence of peptic ulcer is similar in both groups of patients (20.1 vs 29.3% P = n.s.); chronic gastritis was 50% in the control group and 35.4% in the DN2 group (P < 0.01) and dyspepsia without ulcer and gastritis (simple dyspepsia) was significantly more frequent in DM2 patients than in non-diabetics (44.5 vs 20.7%, P < 0.01). Hp infection was documented by histology of gastrointestinal mucosa in 74.4% of the DM2 patients and in 50% of the controls (P < 0.01) (ulcer: 97 vs 71%, P < 0.05; gastritis: 72 vs 43.5%, P < 0.05; simple dyspepsia: 66 vs 35%, P < 0.01, respectively). Autonomic neuropathy was found in 65.2% of the DM2 patients (90.9% of patients with ulcer, 65.5% with gastritis and 53.4% with simple dyspepsia). A significant concordance (84.7%, P < 0.001) was found between the presence of AN and Hp infection. Data provide, for the first time, direct evidence for a higher frequency of Hp infection in dyspeptic patients affected with DM2 than in non-diabetic subjects. In addition, in diabetic patients the frequency of non-ulcer, non-gastritis dyspepsia is two times higher than in non-diabetics and is strictly associated with autonomic neuropathy, acting as a favoring factor for occurrence and recurrence of gastrointestinal disease.

Thrombocytopenia as a sensitive marker of immunologic activity in a patient with autoimmune chronic active hepatitis

The case of autoimmune chronic active hepatitis in a 57-year-old female is reported. Onset was signalled by an abrupt and dramatic thrombocytopenia, which was also the only laboratory parameter able to monitor treatment and progression of the disease. It is concluded that thrombocytopenia together with the presence of antiplatelet-antibodies might be useful markers to monitor the treatment and evolution of the disease.

Non-ulcer dyspepsia and Helicobacter pylori in type 2 diabetic patients: association with autonomic neuropathy

Diabetic patients often suffer from symptoms arising from the gastrointestinal tract. Several factors are considered responsible for these alterations, including abnormalities of gastric motility. Recently Helicobacter pylori (HP) has been identified in a relevant aliquot of subjects with or without gastrointestinal abnormalities, but only scarce and controversial data are available on the prevalence of HP and the association between HP and chronic gastritis or peptic ulcer in diabetic patients. In addition, the possible association between alterations of gastric motility induced by autonomic neuropathy (AN) and the presence of HP has never been evaluated in diabetic subjects. In this study we document the presence of HP in the gastric biopsies of 73% out of a series of 29 patients affected by type 2 diabetes and non-ulcer dyspepsia (3 with oesophagitis, 10 with gastritis, 7 with bulbar duodenitis, and 9 with a normal endoscopy), with a significantly higher prevalence (P < 0.01) in subjects with AN (74%) than in subjects without AN (26%). Two other tests have been compared with the histological evidence of HP (used as golden standard), i.e. the urease test (CP-test) and the assay of anti-HP G-immunoglobulins, both of which were positive in a significantly (P < 0.01) higher percentage of neuropathic patients in comparison with non-neuropathic patients. The sensitivity and the specificity of the CP-test were 96% and 100%, respectively. Similarly, both the sensitivity and the specificity of the assay of IgG HP-Ab were 100%. Since patients affected by non-ulcer dyspepsia and NIDDM complicated by autonomic neuropathy are under a higher risk to be carriers of HP than non-neuropathic or non-diabetic patients. The assay of serum IgG HP-Ab could be used as a screening method, thus avoiding the more expensive and time-consuming endoscopy.

The involvement of the opioid system in human obesity: a study in normal weight relatives of obese people

The involvement of the opioid system in human obesity has been demonstrated, but whether the abnormalities in the endorphinergic system play a primary role in overfeeding and weight gain or represent a simple biochemical feature is still unclear. The objectives of this study were to investigate the effects of both physiological and pharmacological plasma beta-endorphin levels on some metabolic and hormonal parameters in a normal weight, but prone to obesity, young population consisting of first degree relatives of obese subjects and in body mass index-, sex, and age- matched control subjects without a family history of obesity. Each subject underwent a 1-h infusion of synthetic human beta-endorphin at a constant rate of 4.5 ng/kg.min (low rate), then after a 1-week interval, at a rate of 500 micrograms/h (high rate). Under basal conditions, there was no significant difference in plasma glucose and pancreatic hormones (insulin, C peptide, and glucagon) between the two groups, except for plasma beta-endorphin levels, which were significantly (P < 0.01) higher in relatives of obese individuals. The low rate of beta-endorphin infusion induced physiological elevations of plasma opioid levels in both groups; no significant change in plasma glucose and pancreatic products in control subjects; and a significant (at least P < 0.05) rise in plasma insulin, C peptide, and glucagon concentrations in relatives of the obese. The high rate of beta-endorphin infusion produced pharmacological elevations of opioid plasma levels in both groups; significant (at least P < 0.05) increments in plasma glucose and glucagon levels and no appreciable modification of plasma insulin and C peptide levels in the control group; and a significant (at least P < 0.05) positive response of plasma glucose, insulin, C peptide, and glucagon levels in relatives of obese subjects. These findings suggest that 1) opioid peptides at least in part play a primary, rather than secondary, role in some metabolic events of obesity; and 2) both physiological and pharmacological plasma levels of beta-endorphin are able to provoke marked islet hormone release in the early phase of human obesity.

Hyperinsulinemia in offspring of non-insulin-dependent diabetes mellitus patients: the role played by abnormal clearance of insulin

Insulin resistance and hyperinsulinemia are often found in first-degree relatives of non-insulin-dependent diabetes mellitus (NIDDM) patients, and are currently considered a familial trait of this population at increased risk for diabetes. This study was undertaken to determine the role played by the metabolic clearance rate (MCR) of insulin (MCR-I) in the hyperinsulinism of these subjects. The proband population, consisting of 48 subjects aged 29.2 +/- 4.4 (mean +/- SD) years (18 men and 30 women; body mass index, 24.6 +/- 0.8 kg/m2; fasting plasma glucose, 4.54 +/- 0.37 mmol/L), was assigned in random order to four groups (I, II, III, and IV), each receiving a double insulin/glucose infusion (I, 0.025/2.0; II, 0.050/3.5; III, 0.100/6.0; and IV, 0.200/8.0 U/kg.h and mg/kg.min, respectively) to calculate MCR-I and MCR of glucose (MCR-G). Forty (14 men and 26 women) age- and body mass index-matched healthy individuals served as controls. All subjects had a normal response to an oral glucose tolerance test (75 g) according to World Health Organization criteria. Basal plasma insulin and C-peptide levels in probands were significantly (P < .05) higher than in controls in each study group; similarly, MCR-I was significantly (at least P < .05) lower in probands than in controls in all groups. MCR-G was significantly (at least P < .05) decreased in probands as compared with controls of groups III and IV.(ABSTRACT TRUNCATED AT 250 WORDS)

Hemorheological and cardiovascular responses to beta-endorphin and naloxone in healthy subjects and in patients with essential hypertension

The purpose of the present study was to determine if opioid agonism (beta-endorphin) and antagonism (Naloxone) exert rheological and cardiovascular effects in normal humans and in patients with essential hypertension. Eight hypertensive patients were matched for age, sex, and body habitus (body mass index, waist to hip ratio) with eight normotensive healthy subjects. In all subjects, heart rate and blood pressure (continuous automatic recording), blood and plasma viscosity, fibrinogen, hematocrit, and platelet aggregation to ADP were evaluated during an infusion of human synthetic beta-endorphin (0.5 mg/h). On a different day and in randomized order, the subjects were submitted to another beta-endorphin infusion preceded by an i.v. naloxone bolus (5 mg in 5 min). beta-Endorphin and naloxone failed to significantly alter heart rate or blood pressure in both normotensive and hypertensive subjects. In hypertensive patients, beta-endorphin significantly increased blood viscosity and ADP-induced platelet aggregation, but only the former effect was naloxone-sensitive. In normotensive subjects, beta-endorphin caused a transient but significant decrease of platelet aggregation that was reversed by naloxone. These data suggest that beta-endorphin may play some role in the inhibitory control of platelet aggregation in normal subjects. An altered responsiveness of some rheological determinants to beta-endorphin seems to be present in human hypertension.

Detection of early sympathetic cardiovascular neuropathy by squatting test in NIDDM

OBJECTIVE

To determine the role of the squatting test in the detection of early sympathetic neuropathy in patients with non-insulin-dependent diabetes mellitus (NIDDM).

RESEARCH DESIGN AND METHODS

Three groups of nonsmoking, nonobese subjects were studied: 10 healthy subjects, 10 NIDDM patients without autonomic neuropathy (AN), and 10 NIDDM patients with AN defined by the presence of a pathological deep-breathing value. All subjects were given three postural tests: lying-to-standing, sitting-to-standing, and squatting test. Heart rate (HR) and finger arterial pressure were recorded with a noninvasive technique.

RESULTS

Blood pressure (BP) fall (expressed as decremental area) was not significantly different among the groups at standing up after sitting or lying. By contrast, a significantly greater BP drop occurred in NIDDM patients with AN (1,123 +/- 245 mm2) compared with NIDDM patients without AN (460 +/- 232 mm2) or normal subjects (429 +/- 138 mm2, P < 0.001). The HR increase after all the orthostatic maneuvers was smaller in diabetic patients with AN (P < 0.01) compared with that recorded in other groups. Significant correlations were observed between BP fall after squatting and either the expiration:inspiration ratio at deep breathing (r = -0.77, P < 0.001) or the duration of diabetes (r = 0.76, P < 0.001).

CONCLUSIONS

The intrinsic orthostatic load of the squatting test, which is greater than conventional postural maneuvers, makes the squatting test an easy and useful test to detect early orthostatic dysregulation in NIDDM.

Tolrestat for mild diabetic neuropathy. A 52-week, randomized, placebo-controlled trial

OBJECTIVE

To evaluate the effectiveness and safety of tolrestat, an aldose-reductase inhibitor, in patients with mild diabetic autonomic and peripheral neuropathy.

DESIGN

Randomized, placebo-controlled, double-blind 52-week trial.

SETTING

University hospital clinic.

PATIENTS

Forty-five diabetic patients with asymptomatic autonomic neuropathy identified by at least one pathologic cardiovascular reflex test result.

INTERVENTIONS

All patients were given placebo during a 4-week run-in period (single-blind). Twenty patients were randomly assigned to continue to receive placebo, and 25 were assigned to treatment with tolrestat (200 mg/d given in the morning).

MEASUREMENTS AND RESULTS

At 12 months, improvements in nerve functions occurred in patients receiving tolrestat. Compared with baseline values, postural hypotension decreased by a value of 5.9 mm Hg (95% Cl, 1.6 to 8.7); deep-breathing, maximum/minimum heart rate (expiration/inspiration ratio) increased by a value of 0.026 (Cl, 0.015 to 0.036); and lying-to-standing heart rate ratio (30:15 ratio) increased by a value of 0.032 (Cl, 0.027 to 0.052). In the placebo group, all test results except postural hypotension deteriorated. Vibration perception threshold at the malleolus and great toe of the dominant leg improved in the tolrestat group (-1.4; Cl, -3.69 to -1.09) but tended to worsen in the placebo group during the study period. No important side effects were detected in either group.

CONCLUSIONS

The progression of mild diabetic autonomic and peripheral neuropathy may be halted or even reversed by pharmacologic intervention with the aldose-reductase inhibitor tolrestat.

Nicardipine does not cause deterioration of glucose homoeostasis in man: a placebo controlled study in elderly hypertensives with and without diabetes mellitus

The effect of the calcium antagonist nicardipine on insulin secretion and glucose homoeostasis was investigated in elderly hypertensives with and without diabetes mellitus; 15 patients with essential hypertension for at least 10 years and normal glucose tolerance according to standard criteria (Group I) and 15 elderly hypertensive patients affected by Type 2 diabetes mellitus and on treatment with diet or oral drugs (Group 2). In the basal state, all patients were submitted to an oral glucose tolerance test (OGTT, 75 g) and an iv arginine test (30 g), on two different days and in random order. The same tests were repeated after one month of treatment with nicardipine 60 mg/day, in three spaced doses, the last being given 1 h before the post-treatment test. Nicardipine did not change overall glucose homoestasis, as assessed by haemoglobin Alc and fructosamine, nor did it significantly affect the plasma insulin response either to glucose or arginine in Groups 1 and 2. Only the glucagon response to arginine was significantly reduced in diabetic hypertensives. Small, non-significant variations in the metabolic and hormonal parameters were seen in additional two groups of patients (Groups 3 and 4), matched with Groups 1 and 2 for age, sex and diseases, who took capsules containing placebo. Thus, nicardipine did not produce any significant overall alteration in glucose homoestasis when given to elderly diabetic or nondiabetic hypertensive subjects.

Impaired glucose metabolism and reduced insulin clearance in elderly hypertensives

Diabetes mellitus and essential hypertension are characterized by a continuous rise of prevalence with aging and this association may not be casual. Thirty nonobese nondiabetic elderly patients with primary hypertension and 28 healthy normotensives matched for age, sex, and body weight were evaluated for insulin secretion (oral glucose tolerance test, day-long glycemic and insulinemic profiles), action (euglycemic moderately hyperinsulinemic glucose clamp associated with 3H-3-glucose dilution technique), and clearance (120 min insulin/glucose infusion at two prefixed doses). Compared with normotensives, hypertensive elderly patients were characterized by the following: 1) plasma insulin and C-peptide were similar in basal conditions but significantly enhanced in response to both oral glucose and a mixed meal; 2) insulin-stimulated glucose uptake was significantly impaired with a similar rate of hepatic glucose production; 3) exogenous insulin metabolic clearance rate was significantly lower at both insulin infusion rates. The multiple alterations of insulin secretion, action and metabolism found in nonobese nondiabetic elderly hypertensives seem to support a role for this hormone in the regulation of arterial blood pressure.

Physiological elevations of plasma beta-endorphin alter glucose metabolism in obese, but not normal-weight, subjects

The present study was undertaken to evaluate the metabolic and hormonal responses to physiologic elevations of plasma beta-endorphin concentrations in both normal-weight and obese healthy subjects. The infusion of synthetic human beta-endorphin (4.5 ng/kg/min) produced the following: (1) in normal-weight subjects, no significant change of plasma glucose and pancreatic hormones (insulin, C-peptide, and glucagon), a significant plasma free fatty acids (FFA) increase, and a suppression of glycerol plasma levels; (2) in obese subjects, significant increases of glucose, insulin, C-peptide, and glucagon, a progressive decline of circulating FFA, and no change in glycerol plasma levels. In obese subjects, the intravenous administration of naloxone, given as a bolus (5 mg injected in 5 minutes) before the start of beta-endorphin infusion, reduced the plasma glucose response to the opioid by approximately half, annulled the pancreatic hormonal responses, and also reduced the FFA, but not glycerol, response. In normal-weight subjects, naloxone pretreatment did not induce any change of the flat glucose and hormonal responses to beta-endorphin, but reversed its effects on circulating FFA and glycerol. These data suggest that physiological elevations of plasma beta-endorphin concentrations produce metabolic and hormonal effects in obese subjects significantly different from those occurring in normal-weight subjects; these effects are partially naloxone-sensitive, suggesting the mediation of endogenous opioid receptors.

Decreased insulin clearance as a feature of essential hypertension

Several studies report that essential hypertension is associated with hyperinsulinemia. This condition may depend on enhanced pancreatic insulin secretion and/or a decreased MCR of the circulating hormone. Twenty-five nonobese glucose-normotolerant patients with primary hypertension were divided into 5 groups, each consisting of 5 subjects. Each group was submitted to continuous 120-min double infusion of different doses of insulin (group I, 0.025; II, 0.05; III, 0.1; IV, 0.2; V, 0.4 U/kg.h) and glucose (I, 2; II, 3.5; III, 6; IV, 8; V, 10 mg/kg.min). The same procedures were applied to 25 healthy normotensive volunteers. Basal and steady state plasma levels of glucose, insulin, and C-peptide were significantly (P less than 0.05 or less) higher in hypertensive patients than in control subjects of all groups. The MCR of insulin (milliliters per kg/min) at all insulin-glucose infusion rates was significantly (P less than 0.05 or less) lower in hypertensive than normotensive subjects. Despite the significantly higher steady state plasma insulin levels in hypertensives, the MCR of glucose (milliliters per kg/min) was significantly (P less than 0.05 or less) lower in hypertensive than normotensive subjects. These results suggest that an altered insulin removal may contribute to the hyperinsulinemia found in the essential hypertensive subjects. In addition, a defect in insulin-stimulated glucose uptake which persists at supraphysiological insulin concentrations is confirmed in this population.

Sensorimotor evaluation of ano-rectal complex in diabetes mellitus

To evaluate the status of ano-rectal complex in diabetic patients, 20 patients with no fecal incontinence and/or local ano-rectal disorders and 18 normal subjects underwent to: 1) ano-rectal manometry; 2) defecography; and 3) rectal sensation tests. In all subjects, the five classic cardiovascular reflexes tests were performed to detect autonomic neuropathy. No significant difference between diabetic patients and controls was found in length, maximum resting pressure and strength of phasic external anal sphincter or anal canal at ano-rectal manometry; similarly, no significant difference between diabetic and normal subjects was found by the same technique in threshold and amplitude of ano-rectal inhibitory reflex. Ano-rectal angle of diabetic patients was not significantly different from normals both at resting and during straining at defecographic study. By rectal sensation testing, it was possible to demonstrate a significant difference between diabetic and normal subjects in perception of rectal distension (87.5 +/- 27.5 vs 39.2 +/- 6.5 ml, p less than 0.05; mean +/- SEM) and of stimulus of defecation (147.0 +/- 56.3 vs 52.9 +/- 18.5 ml, p less than 0.001) but not in perception of maximum tolerable volume (343.5 +/- 69.9 vs 322.0 +/- 48.5 ml, p = NS). No relationship was found between these results and the score of autonomic neuropathy and/or duration of diabetic disease. These data suggest that an early involvement of only sensory parasympathetic fibers of ano-rectal complex occurs in diabetic patients without gastrointestinal symptoms.

Restoration of sensitivity to sulfonylurea after strict glycaemic control with insulin in non-obese type 2 diabetic subjects

Ten non-obese type 2 diabetic patients with secondary failure to sulfonylureas received an intensive insulin therapy (four doses schedule) for 90 days. The glycaemic control was poor at entry (HbA1c = 11.7 +/- 1.2%) and ameliorated significantly after insulin (HbA1c = 7.1 +/- 0.7%, p less than 0.01). The reintroduction of the sulfonylurea after insulin withdrawal resulted in a persistent satisfactory long-term control (300 days) in all, but two diabetics responded no more after about 3 and 4 months of clinical remission (good control on sulfonylurea). Both basal and stimulated (iv glucagon and mixed meal) beta-cell secretory activity increased significantly at 3 months and declined thereafter without falling below baseline values. Three months of strict metabolic control seem to restore the sensitivity to sulfonylurea by enhancing beta-cell secretory activity in non-obese type 2 diabetic patients.