Exercise responses in patients with IDDM

OBJECTIVE

The hemodynamic, respiratory, and metabolic responses to exercise were studied in IDDM patients and control subjects to detect diabetic cardiomyopathy.

RESEARCH DESIGN AND METHODS

Eight subjects aged 25-40 years with diabetes of at least 10 years' duration were compared with eight control subjects aged 21-46 years. All subjects underwent a progressive incremental bicycle exercise test with measurement of gas exchange, blood glucose, lactate, fat metabolite, and catecholamine levels and two steady-state exercise tests with measurement of cardiac output by a CO2 rebreathing method. A new first-pass radionuclide method was used to measure cardiac ejection fractions (EFs) at rest, peak exercise, and steady-state exercise.

RESULTS

The peak achieved oxygen consumption was similar in the diabetic and control subjects (29.9 [25.1-34.6] and 31.4 [26.9-35.9] ml.min-1.kg-1, respectively; mean [95% CI]). There were no significant differences in heart rate, double product, ventilation, respiratory exchange ratio, or ventilatory equivalents for oxygen and CO2 during the incremental test. Glucose levels were higher in the diabetic subjects, but there were no significant differences in levels of lactate, catecholamines, free fatty acids, glycerol, or beta-hydroxybutyrate. Left ventricular EF fell from rest to peak exercise within the diabetic group (66.0% [59.6-72.4] at rest; 53.6% [45.6-61.6] at peak; P < 0.05) but this did not differ significantly from the control group (58.7% [52.3-65.1] at rest; 60.3% [48.9-71.7] at peak). Right ventricular EFs were similar in each group, and there was no reduction in peak filling rate to suggest diastolic dysfunction. The cardiac output responses to exercise were also similar in the two groups.

CONCLUSIONS

There is no evidence of impairment of the exercise response in subjects with long-standing diabetes, and the apparent fall in left ventricular EF at peak exercise could be related to hemodynamic adaptation.

Treatment of diabetic ketoacidosis using normalization of blood 3-hydroxybutyrate concentration as the endpoint of emergency management. A randomized controlled study

OBJECTIVE

To compare the efficacy of an extended insulin regimen using correction of hyperketonemia as endpoint with a more conventional regimen in the treatment of diabetic ketoacidosis.

RESEARCH DESIGN AND METHODS

A total of 22 patients admitted to a Belfast teaching hospital with clinical and biochemical features of diabetic ketoacidosis (pH < 7.25 and/or bicarbonate < 16 mmol/l) were randomized to either conventional or extended insulin regimens. In the conventional regimen, insulin was administered at 5 U/h until near-normoglycemia (blood glucose < or = 10 mmol/l) and then administered at a reduced rate until clinical recovery. In the extended regimen, administration of insulin at 5 U/h was continued beyond attainment of normoglycemia, until resolution of hyperketonemia (3-hydroxybutyrate < 0.5 mmol/l). Main outcome measures were 3-hydroxybutyrate and bicarbonate levels during the 24 h after attainment of near-normoglycemia.

RESULTS

After near-normoglycemia, correction of hyperketonemia was achieved earlier with the extended treatment (5.9 +/- 0.8 vs. 21.8 +/- 3.4 h, P = 0.0004 [mean +/- SD]). The area under the curve of 3-hydroxybutyrate against time for 24 h after near-normoglycemia was reduced with the extended treatment (24.9 +/- 3.8 vs. 55.9 +/- 6.7 mmol.l-1.h-1, P = 0.001). These differences remained statistically significant after adjustment for higher baseline levels of 3-hydroxybutyrate at near-normoglycemia in the extended treatment group. Bicarbonate levels at 6 and 12 h after near-normoglycemia were not significantly different between groups.

CONCLUSIONS

The extended insulin regimen, which was easy to implement at ward level, produced a more rapid resolution of ketosis than the conventional regimen.

Metformin

Metformin, a dimethylbiguanide, was first synthesized in 1929 and was shown to be a potent hypoglycemic agent. It was rediscovered in 1957 and was widely used in Europe to treat obese type II patients. Metformin resurfaced in the 1980s and was shown to increase insulin sensitivity; this has led to its introduction to clinical practice in the United States for the first time. The small risk of lactic acidosis is now well documented and appropriate therapeutic guidelines have been established. Metformin is a sage and effective drug for management of non-insulin-dependent diabetes mellitus.

A fuzzy linguistic model for the prediction of carpal tunnel syndrome risks in an occupational environment

This research presents the development and evaluation of a fuzzy linguistic model designated to predict the risk of carpal tunnel syndrome (CTS) in an occupational setting. CTS has become one of the largest problems facing ergonomists and the medical community because it is developing in epidemic proportions within the occupational environment. In addition, practitioners are interested in identifying accurate methods for evaluating the risk of CTS in an occupational setting. It is hypothesized that many factors impact an individual's likelihood of developing CTS and the eventual development of CTS. This disparity in the occurrence of CTS for workers with similar backgrounds and work activities has confused researchers and has been a stumbling block in the development of a model for widespread use in evaluating the development of CTS. Thus this research is an attempt to develop a method that can be used to predict the likelihood of CTS risk in a variety of environments. The intent is that this model will be applied eventually in an occupational setting, thus model development was focused on a method that provided a usable interface and the desired system inputs can also be obtained without the benefit of a medical practitioner. The methodology involves knowledge acquisition to identify and categorize a holistic set of risk factors that include task-related, personal, and organizational categories. The determination of relative factor importance was accomplished using analytic hierarchy processing (AHP) analysis. Finally a mathematical representation of the CTS risk was accomplished by utilizing fuzzy set theory in order to quantify linguistic input parameters. An evaluation of the model including determination of sensitivity and specificity is conducted and the results of the model indicate that the results are fairly accurate and this method has the potential for widespread use. A significant aspect of this research is the comparison of this technique to other methods for assessing presence of CTS. The results of this evaluation technique are compared with more traditional methods for assessing the presence of CTS.

Macrovascular disease and hyperglycaemia: 10-year survival analysis in Type 2 diabetes mellitus: the Belfast Diet Study

The relationship between macrovascular disease and blood glucose control in long-term follow-up of Type 2 (non-insulin-dependent) diabetes mellitus is difficult to study because of the gradual rise in fasting plasma glucose due to ongoing beta-cell failure. We used time-dependent covariates in Cox's proportional hazards model to allow variables measured annually during a 10-year prospective follow-up to be related to risk of myocardial infarction or cerebrovascular accident. Data for 432 newly diagnosed diabetic patients were available, 112 of whom suffered myocardial infarction (fatal or non-fatal). Analysis of baseline measurements only gave relative hazards (95% CL) of 1.04 (0.99, 1.09) per mmol l(-1) increase in fasting plasma glucose, 1.43 (1.12, 1.83) per decade increase in age and 1.07 (0.98, 1.17) per 10 % increase in percentage of ideal weight. Analysis incorporating ongoing measurements gave corresponding figures of 1.07 (1.02, 1.12) for fasting plasma glucose, 1.64 (1.23, 2.20) for age and 1.06 (0.95, 1.18) for percentage of ideal weight. The risk of myocardial infarction while on insulin treatment 1.09 (0.58, 2.06) or oral agents 1.41 (0.86, 2.31) was not significantly elevated relative to dietary treatment. Baseline smoking status, systolic blood pressure, and previous myocardial infarction were also significant predictors of myocardial infarction. Similar relationships were found for cerebrovascular accident and total mortality. Increasing fasting plasma glucose is a significant independent predictor of macrovascular disease in diabetes.

Phylogenetic survey of soluble saxitoxin-binding activity in pursuit of the function and molecular evolution of saxiphilin, a relative of transferrin

Saxiphilin is a soluble protein of unknown function which binds the neurotoxin, saxitoxin (STX), with high affinity. Molecular characterization of saxiphilin from the North American bullfrog, Rana catesbeiana, has previously shown that it is a member of the transferrin family. In this study we surveyed various animal species to investigate the phylogenetic distribution of saxiphilin, as detected by the presence of soluble [3H]STX binding activity in plasma, haemolymph or tissue extracts. We found that saxiphilin activity is readily detectable in a wide variety of arthropods, fish, amphibians, and reptiles. The pharmacological characteristics of [3H]STX binding activity in phylogenetically diverse species indicates that a protein homologous to bullfrog saxiphilin is likely to be constitutively expressed in many ectothermic animals. The results suggest that the saxiphilin gene is evolutionarily as old as an ancestral gene encoding bilobed transferrin, an Fe(2+)-binding and transport protein which has been identified in several arthropods and all the vertebrates which have been studied.

Insulin action and hepatic glucose cycling in Cushing's syndrome

OBJECTIVE

Although it is well established that hypercortisolism causes insulin resistance, the mechanisms responsible for impaired insulin action in Cushing's syndrome are unclear. This study investigated the contribution of the glucose/glucose-6-phosphate substrate cycle (G/G6P).

PATIENTS

Eight patients with Cushing's syndrome and seven control subjects were studied. All had normal fasting plasma glucose.

DESIGN

Insulin action was assessed using the euglycaemic glucose clamp at insulin infusion rates of 0.4 and 2.0 mU/kg/min combined with a simultaneous infusion of [2(3)H]- and [6(3)-H]-glucose. Glucose/ glucose-6-phosphate cycle activity was calculated as the difference in glucose turnover rates determined separately for [2(3)H]- and [6(3)H]-glucose by selective enzymatic detritiation.

MEASUREMENTS AND RESULTS

Exogenous glucose infusion rates required to maintain euglycaemia were significantly lower in Cushing's patients compared to controls, during the 0.4 mU/kg/min (7.8 +/- 1.2 vs 15.7 +/- 0.5 mumol/kg/min, P < 0.001) and the 2.0 mU/ kg/min insulin infusions (26.2 +/- 2.8 vs 51.5 +/- 3.5 mumol/ kg/min, P < 0.001). Endogenous glucose production was similar in both groups in the postabsorptive state (10.2 +/- 0.3 vs 10.8 +/- 0.4 mumol/kg/min, P = 0.50) and suppressed to a similar degree during hyperinsulinaemia. G/G6P cycle activity was markedly increased in the Cushing's group in the postabsorptive state (5.4 +/- 1.1 vs 2.0 +/- 0.5 mumol/kg/min, P = 0.028) and during the 0.4 mU/kg/min (3.2 +/- 0.6 vs 1.2 +/- 0.4 mumol/kg/min, P = 0.014) and 2.0 mU/kg/min insulin infusions (3.3 +/- 0.8 vs 1.1 +/- 0.5 mumol/kg/min, P = 0.049).

CONCLUSIONS

Patients with Cushing's syndrome show marked peripheral insulin resistance and enhanced hepatic G/G6P cycle activity. In the fasting state increased glucose/glucose-6-phosphate cycle activity may be a protective mechanism limiting hyperglycaemia. During hyperinsulinaemia G/G6P cycle activity was increased but insulin resistance was predominantly due to reduced peripheral glucose uptake.

Community-acquired lower respiratory tract infection: implementation of an antibiotic protocol

Enthusiastic formulation of clinical guidelines continues to increase but although theoretical difficulties in guideline implementation have been recognised, little attention has been paid to their effectiveness in everyday clinical practice. The introduction of a protocol for empirical treatment of lower respiratory tract infection (PETRI) to an acute medical take-in unit in Belfast is described. Early involvement of all relevant staff, preparation of user-friendly flow charts, and imaginative publicity, resulted in an initial implementation rate of 75%. The role of implementation as a significant rate-limiting step in the audit cycle is emphasised.

Skeletal muscle blood flow is not a determinant of insulin resistance in essential hypertension

OBJECTIVE

To investigate the haemodynamic effects of insulin and their relationship to insulin resistance in essential hypertension.

DESIGN

Group comparison between patients with essential hypertension and normal controls.

SETTING

Outpatient clinics serving the greater Belfast area.

PATIENTS

Eleven patients with essential hypertension and eight age-, sex- and weight-matched control subjects were recruited. Administration of all antihypertensive agents to the hypertensive patients was stopped 6 weeks prior to the study.

METHODS

Leg blood flow was measured using venous occlusion plethysmography. Insulin action was assessed using the hyperinsulinaemic euglycaemic clamp technique.

RESULTS

The hypertensive subjects were insulin-resistant compared with the normal controls. Insulin infusion resulted in similar increases in calf blood flow in the two groups. There was no correlation between calf blood flow and measurements of insulin sensitivity in either group.

CONCLUSIONS

Differences in whole-body glucose uptake in hypertensive and control subjects are not likely to be related to differences in insulin-induced stimulation of muscle blood flow.

Clinical significance of insulin resistance

Insulin resistance has emerged in the last 20 years as a concept familiar to clinicians in many specialties. No easily performed laboratory test is available to assess insulin action in routine clinical practice. Several rare syndromes of severe insulin resistance are recognized but most clinicians will encounter insulin resistance as a manifestation of common diseases. Physiological and treatment induced changes in insulin sensitivity influence insulin doses required in insulin-dependent diabetes mellitus. In non-insulin-dependent diabetes mellitus insulin resistance is fundamental to pathogenesis but it is also influenced by standard dietary and pharmacological treatment, and probably mediated by changes in prevailing glycaemia. Antihypertensive agents appear to have diverse effects on the insulin resistance of essential hypertension though the long term significance of these remains unclear. The importance of insulin as a risk factor for coronary heart disease and the concept of an insulin resistance syndrome as a common precursor of conditions with increased vascular risk remains controversial.

Association between insulin secretory pulse frequency and peripheral insulin action in NIDDM and normal subjects

Abnormalities of both insulin secretion and insulin action occur in NIDDM. It is not clear, however, which is the primary defect. Recently, it has been suggested that the frequency of insulin pulses is an important factor regulating insulin action in normal humans. We examined the relationship between pulsatile insulin secretion and insulin action in eight NIDDM subjects and eight health matched control subjects. Insulin action was assessed prevailing fasting glucose levels before and after hype insulinemia (2-h insulin infusion at 2.0 mU / kg / min). Pulsatility of insulin was assessed by sampling every 2 min for 90 min after an overnight fast and identifying insulin pulses using the computer program Pulsar. Fasting plasma glucose and postabsorptive endogenous glucose production were both greater in diabetic subjects compared with control subjects (10.1 +/- 1.2 vs. 5.4 +/- 0.1 mmol/l, P < 0.01; 11.8 +/- 0.8 vs. 9.9 +/- 0.4 micromol / kg / min, P < 0.05). During the 2.0 mU insulin infusion, glucose clearance was lower in the diabetic subjects (3.6 +/- 0.7 vs. 6.9 +/- 0.5 ml / kg / min), P < 0.05), whereas endogenous glucose production was suppressed to a similar degree in both groups (4.5 +/- 0.8 vs. 3.6 +/- 0.7 micromol x kg(-1) x min(-1), NS). The frequency of insulin pulses and glucose clearance were negatively correlated in both diabetic subjects (r = -0.75, P < 0.05) and normal control subjects (r = -0.82, P < 0.01). This negative correlation was also present in both groups taken together (r = -0.72, P < 0.001). There was no correlation between insulin pulse frequency and endogenous glucose production either in the fasting state or during hyperinsulinemia. We concluded that the frequency of insulin pulses and peripheral insulin sensitivity are closely linked in NIDDM and normal subjects.

Unnecessary delays in accident and emergency departments: do medical and surgical senior house officers need to vet admissions?

Work was carried out to determine whether patients requiring emergency medical or surgical admission to hospital via accident and emergency (A&E) departments benefit from initial assessment by the ward senior house officer (SHO) as well as the A&E SHO. Two comparable consultant-led A&E departments sharing the same catchment population and receiving similar numbers of new patients each year were studied. A panel of four consultants audited the A&E notes and in-patient records of consecutive emergency medical and surgical patients admitted to two hospitals over the same 6 month period. In one hospital patients were seen and admitted by the A&E SHO alone. In the other hospital patients were seen by the A&E SHO and the medical or surgical SHO from the admitting unit. Diagnostic errors, inappropriate admissions to hospital and admission of patients to inappropriate wards were used as outcome measures. There was no significant difference in the rates of diagnostic error or inappropriate admissions between those patients seen by an A&E SHO only, and those seen in A&E by the A&E and ward SHOs. Detaining emergency medical and surgical patients in the A&E department for further assessment by ward SHOs does not alter inappropriate admission rate or improve diagnostic accuracy.

A comparison of the effects of low- and conventional-dose thiazide diuretic on insulin action in hypertensive patients with NIDDM

In conventional doses, thiazide diuretics impair glucose tolerance and decrease insulin sensitivity, making them an unpopular choice for treating diabetic patients with hypertension. However, use of low-dose thiazide diuretics may avoid the adverse metabolic effects seen with conventional doses. In a double-blind, randomised crossover study we assessed peripheral and hepatic insulin action in 13 hypertensive non-insulin-dependent diabetic patients after a 6-week placebo run-in and following two 12-week treatment periods with either low (1.25 mg) or conventional (5.0mg) dose bendrofluazide. There were no differences between doses in their effects on systolic and diastolic blood pressure. Bendrofluazide 1.25 mg had significantly less effect on serum potassium, uric acid, fasting glucose and HbA1C concentrations than the 5.00 mg dose. Exogenous glucose infusion rates required to maintain euglycaemia were significantly different between doses (p < 0.05) with conventional-dose bendrofluazide worsening peripheral insulin resistance compared to baseline (23.8 +/- 2.9 vs 27.3 +/- 3.5 mumol.kg-1.min-1, p < 0.05) and low-dose bendrofluazide producing no change compared to baseline (26.8 +/- 3.6 vs 27.3 +/- 3.5 mumol.kg-1.min-1, p = NS). Postabsorptive endogenous glucose production was higher on treatment with bendrofluazide 5.0 mg compared to 1.25 mg (11.7 +/- 0.5 vs 10.2 +/- 0.3 mumol.kg-1.min-1, p < 0.05) and suppressed to a lesser extent following insulin (4.0 +/- 0.7 vs 2.0 +/- 0.4 mumol.kg-1.min-1, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Failure of complete suppression of endogenous glucose production by euglycaemic hyperinsulinaemia in normal humans

In normal subjects, endogenous glucose production (EGP) is usually assumed to be completely suppressed during euglycaemic clamp studies performed at high insulin levels (> 100 mU L-1). However, this assumption is based on non-steady-state tracer measurements of EGP which are prone to negative errors. We have used purified [6-(3)H]glucose in an optimal tracer infusion protocol to assess the suppression of EGP during 4 h euglycaemic clamps in eight normal men. An insulin infusion rate of 5 mU kg-1 min-1 was chosen to achieve supraphysiological (> 500 mU L-1) plasma insulin concentrations. Using a labelled exogenous glucose infusion, plasma glucose (mean +/- SEM 5.3 +/- 0.1 mmol L-1) and glucose specific activities (mean 100 +/- 3% of basal) were maintained constant from 80 to 240 min. During hyperinsulinaemia, isotopically determined glucose appearance rates (Ra) were greater than glucose infusion rates (GIR) throughout the euglycaemic clamp period (P < 0.001) and EGP (Ra-GIR) was always greater than zero. In seven of the eight subjects studied EGP was partly suppressed but showed a wide variation (EGP 5 to 91% of basal at 80-120 min and 12 to 87% of basal at 200-240 min) while in one subject EGP rose above basal (by 72% at 80-120 min and 49% at 200-240 min). We conclude that EGP is not completely suppressed during euglycaemic clamps at high insulin levels.

Rehabilitation of disability benefit claimants other than dependency

Canadian sponsors of successful rehabilitation programs have found they offer impressive benefits for participants in long-term disability plans, as well as for employers and insurers. However, multiemployer plans frequently are not able to capitalize on these benefits.

Insulin and C-peptide secretion in non-insulin-dependent diabetes mellitus and its response to dietary therapy

We studied insulin and C-peptide levels in patients with non-insulin-dependent diabetes mellitus (NIDDM) during standard oral or intravenous glucose tolerance tests (GTT) at the time of diagnosis and after 3 months dietary therapy. On the second occasion they also had an 'augmented' GTT, in which slow intravenous infusion of glucose raised basal plasma glucose to a level similar to that at the time of diagnosis. Eight patients had oral tests, and seven patients intravenous tests. In both groups, dietary therapy significantly reduced fasting and peak plasma glucose (p < 0.05 for oral; p < 0.01 for intravenous GTT). Serum insulin levels during conventional oral GTT were not significantly different after dietary therapy compared to diagnosis, but were significantly higher during the 'augmented' oral GTT (p < 0.05). In those patients who underwent intravenous GTT, there was a significant increase in both the total amount of insulin secreted (0-60 min) and in first-phase insulin secretion (0-10 min) during the 'augmented' test compared to diagnosis (p < 0.01), but first-phase insulin secretion during the conventional intravenous GTT was unchanged. Serum C-peptide responses were also greater during 'augmented' tests (p < 0.05), similar in pattern to serum insulin. There is a relative deficiency in insulin secretion in untreated NIDDM, which can be reversed by dietary therapy. It is essential to study insulin and C-peptide secretion in controlled 'fasting' glucose conditions.

Microalbuminuria as identified by a spot morning urine specimen in non-insulin-treated diabetes: an eight-year follow-up study

This study followed up a cohort of patients with microalbuminuria identified on a spot morning urine sample 8 years earlier and aimed to determine if a spot morning urinary albumin concentration was able to identify patients with non-insulin treated diabetes at increased risk of mortality and progression to nephropathy. In 1984, 47 of 216 patients chosen by random selection from our teaching hospital-based diabetes clinic were identified as having microalbuminuria (urinary albumin concentration 35-300 micrograms ml-1). Subjects were compared with an age-matched control group from the 1984 cohort who did not have microalbuminuria. Eight years later, 22 of 47 (46.8%) patients with microalbuminuria had died compared to 10 of 47 (21.3%) patients without albuminuria (p < 0.05). The majority of deaths were from cardiovascular disease (53.1%). Logistic regression showed microalbuminuria to be an independent predictor of mortality, not influenced by age, duration of diabetes, blood pressure, glycosylated haemoglobin or creatinine at the initial examination. Eight years later, in the group with initial microalbuminuria, eight still had microalbuminuria and five patients had developed nephropathy. In the group without albuminuria in 1984, only one patient had progressed to microalbuminuria and no patients to nephropathy. In conclusion, a spot urinary albumin concentration is of value in identifying patients with an increased risk of mortality or progression to nephropathy, and is simple to obtain at a clinic.

Is a random urinary albumin concentration a useful screening test in insulin-treated diabetic patients?

The debate continues on how to screen for microalbuminuria in clinical practice in patients with insulin-dependent diabetes mellitus. Our study assesses the value of a spot morning urine specimen obtained at a clinic visit. In 1984, as part of a randomised survey of our diabetes clinic, 43 of 249 patients with insulin treated diabetes mellitus, were found to have microalbuminuria (urinary albumin concentration 35-300 ug ml-1) on a spot morning urine sample. These subjects were compared with an age-matched control group from the 1984 cohort who did not have microalbuminuria. Eight years later, in the group with microalbuminuria, 10 had died compared to six in the control group (p = 0.17) with 62.5% of all deaths being from cardiovascular disease. In the group with microalbuminuria, 10 of 27 still had incipient nephropathy while five had progressed to nephropathy. In the group without microalbuminuria only three of 33 patients had progressed to microalbuminuria while none had progressed to nephropathy. In conclusion a spot morning urine sample is a useful screening test to identify patients at risk of progression to nephropathy.

Effects of low dose versus conventional dose thiazide diuretic on insulin action in essential hypertension

OBJECTIVE

To see whether low dose thiazide diuretics given to patients with essential hypertension might avoid the adverse metabolic consequences seen with conventional doses.

DESIGN

Double blind randomised crossover study of two 12 week treatment periods with either low dose (1.25 mg) or conventional dose (5.0 mg) bendrofluazide given after a six week placebo run in period.

SETTING

Outpatient clinics serving the greater Belfast area.

SUBJECTS

16 white non-diabetic patients (9 male) under 65 with essential hypertension recruited from general practices within the greater Belfast area.

MAIN OUTCOME MEASURES

Systolic and diastolic blood pressure and peripheral and hepatic insulin action.

RESULTS

One man failed to complete the study. There were no differences between doses in their effects on systolic and diastolic blood pressure. Bendrofluazide 1.25 mg had substantially less effect on serum potassium concentration than the 5.0 mg dose. There were no intertreatment differences in fasting glucose, insulin, cholesterol, and triglyceride concentrations. Bendrofluazide 5.0 mg significantly increased postabsorptive endogenous glucose production compared with baseline (mean 10.9 (SD 1.2) v 10.0 (0.8) mumol/kg/min), whereas bendrofluazide 1.25 mg did not. Postabsorptive endogenous glucose production was significantly higher with bendrofluazide 5.0 mg compared with 1.25 mg (10.9 (1.2) v 9.9 (0.8) mumol/kg/min) but was suppressed to a similar extent after insulin (bendrofluazide 5.0 mg 2.8 (1.5) mumol/kg/min v bendrofluazide 1.25 mg 2.2 (1.5) mumol/kg/min). Exogenous glucose infusion rates required to maintain euglycaemia were not significantly different between doses and were similar to baseline.

CONCLUSIONS

Bendrofluazide 1.25 mg is as effective as conventional doses but has less adverse metabolic effect. In contrast with conventional doses, low dose bendrofluazide has no effect on hepatic insulin action. There is no difference between low and conventional doses of bendrofluazide in their effect on peripheral insulin sensitivity.