Antidiabetic properties of ethanolic extract of Cnidoscolus aconitifolius on alloxan induced diabetes mellitus in rats

This research was designed to investigate the antidiabetic properties of ethanolic extract of Cnidoscolus aconitifolius in alloxan-induced diabetes mellitus in Wistar male albino rats. Thirty male albino rats were used. Diabetes mellitus was induced in five of the six groups (B-F) by a single intra-peritoneal injection at the dose of 100mg/kg after normal fasting blood glucose had been determined. Group A served as the positive control while groups C-E received 100mg/kg, 500mg/kg and 1000mg/kg of Cnidoscolus aconitifolius extract respectively. Group B did not received any treatment while group F received chlorpropamide, a standard drug used in the treatment of diabetes mellitus. Blood glucose and body weights were monitored weekly for four weeks. Plasma lipids and electrolytes such as Total cholesterol, Triglyceride, Low Density Lipoproteins (LDL), High Density Lipoproteins (HDL), Creatinine and Blood Urea Nitrogen (BUN) were determined after four weeks of treatment with Cnidoscolus aconitifolius extract. The results show significant reduction (P<0.001) in the blood glucose in group C (100mg/kg of Cnidoscolus aconitifolius) when compared with diabetic control (Alloxan only) and other treatment groups. There was gradual increase in weight of all treatment groups compared with the diabetic control, which had progressive weight loss. Plasma cholesterol levels also significantly reduced (P<0.001) in rats treated with 1,000mg/kg Cnidoscolus aconitifolius extract. From this study, Cnidoscolus aconitifolius extract was found to considerably reduce blood glucose and plasma cholesterol levels and progressively increase weight gain in diabetic treated rats confirming its traditional use for the treatment of diabetes.

Ameliorative effects of Cnidoscolus aconitifolius on alloxan toxicity in Wistar rats

BACKGROUND

Diabetes has been associated with several complications occasioned by oxidative stress. Thus, in treatment of the condition, these complications must also be taken into consideration. This study evaluates the effect of Cnidoscolus aconitifolius complications of diabetes induced by alloxan, on haematology and sperm morphometry using the Wistar rats.

METHODS

Diabetes was induced in 25 rats using alloxan. The diabetic rats were then divided into five groups B-F consisting of five rats per group. Groups C-E were administered with 100 mg/kg, 500 mg/kg and 1000 mg/kg of ethanolic leaves extract of Cnidoscolus aconitifolius, respectively, for four weeks post treatment with alloxan, while group F received Chlorpropamide (Diabenes®, Pfizer). The diabetic rats in group B were not treated while group A served as the non diabetic control.

RESULT

Following treatment with alloxan, there was anaemia, thrombocytopenia and leucopenia, while the sperm count, motility and live/dead ratio were significantly reduced. Sperm morphological abnormalities and erythrocyte osmotic fragility also increased significantly. Following treatment of alloxan treated-rats with the extract, there were significant increases in the PCV, RBC, Hb, WBC, MCV and the platelet values. Erythrocyte osmotic fragility, sperm count, motility and live/dead ratio also improved significantly.

CONCLUSION

Cnidoscolus aconitifolius extract was found to ameliorate the effects of alloxan induced diabetes on the haematology but not on the abnormal sperm morphometry in rats.

Hepatic glucose-6-phosphatase activity in non-insulin dependent diabetics. Effect of enzyme-inducing drugs

The role of glucose-6-phosphatase (G6Pase) in postreceptional glucose handling in non-insulin dependent diabetics ( NIDDs ) was in investigated by comparing the enzyme values in diagnostic liver biopsy samples with fasting blood glucose (BG), immunoreactive insulin (IRI) and plasma antipyrine half-life (T/2). The NIDDs , treated with sulphonylureas, had elevated serum aminotransferase and alkaline phosphatase values associated with fatty liver with or without fibrosis. G6Pase activity was reduced in the NIDDs compared with subjects who had undergone gallstone surgery (p less than 0.001), insulin dependent diabetics (p less than 0.001), and age- and sex-matched non-diabetics (p less than 0.001). G6Pase was inversely related to BG and antipyrine T/2, but not to IRI or conventional liver function tests. Therapy with phenobarbital and medroxyprogesterone acetate, known inducers, increased G6Pase activity, shortened antipyrine T/2, reduced BG and did not alter IRI, in four NIDDs . Low liver G6Pase activity in NIDDs may hence be one factor underlying the impaired glycemic control.

The Effect of Deinsuring Chlorpropamide on the Prescribing of Oral Antihyperglycemics for Nova Scotia Seniors’ Pharmacare Beneficiaries

On behalf of the Nova Scotia Seniors' Pharmacare Program, the Drug Evaluation Alliance of Nova Scotia developed a multicomponent intervention plan to facilitate the removal of chlorpropamide as an insured benefit. Chlorpropamide has caused serious hypoglycemia in seniors to a greater extent than some other agents. Pharmacy administrative claims were used to compute monthly use rates for insulin and each oral antihyperglycemic drug from January 1, 2000-December 30, 2002, in an intervention cohort (patients receiving chlorpropamide) and a control cohort (patients receiving an antihyperglycemic agent other than chlorpropamide). Initially, 630 patients were receiving chlorpropamide therapy. By the time chlorpropamide was deinsured, only 10% of the treatment cohort continued receiving chlorpropamide; shortly after deinsurance, no beneficiaries continued receiving the drug. The antihyperglycemics with the greatest increase in prescription were glyburide and gliclazide. The deinsuring of chlorpropamide and the educational strategies that accompanied it resulted in the selection of more appropriate antihyperglycemics for Nova Scotia seniors.

The advantages and disadvantages of a 'herbal' medicine in a patient with diabetes mellitus: a case report

BACKGROUND

Patient-initiated alternative treatments in the management of chronic conditions are common and increasing in the United Kingdom. To date, there have been no reports of herbal medicine use alone in the management of diabetes mellitus. We report here the case of a man who attained excellent glycaemic control using a 'herbal' medicine and reveal how important it was to identify the products of active constituents.

CASE REPORT

A 48-year-old man attending our clinic in Tooting, South London with known Type 2 diabetes, with evidence of both micro- and macro-vascular diabetes-related complications, was poorly controlled despite a drug regimen consisting of oral metformin and twice daily insulin. He went to India for at least 1 year and on returning to the clinic had excellent glycaemic control off all diabetic medication. While away he had started himself on a regimen of three different 'herbal' balls. Samples of blood were found to contain chlorpropamide in a therapeutic concentration; chlorpropamide was also found in one of the balls. He has been counselled on the potential risks associated with chlorpropamide and his treatment reverted to a more conventional treatment regimen.

CONCLUSIONS

General practitioners and hospital physicians should be alert to those patients returning from abroad on effective 'herbal' medications that these may in fact contain an active ingredient.

Hypoglycemic effect of Sclerocarya birrea [(A. Rich.) Hochst.] [Anacardiaceae] stem-bark aqueous extract in rats

This study was undertaken to evaluate the hypoglycemic effect of Sclerocarya birrea [(A. Rich.) Hochst.] subspecies caffra (Sond.) Kokwaro [family: Anacardiaceae] stem-bark aqueous extract in normal (normoglycemic) and in streptozotocin (STZ)-treated, diabetic Wistar rats. In one set of experiments, graded doses of S. birrea stem-bark aqueous extract (SB, 100-800 mg/kg p.o.) were separately administered to groups of fasted normal and fasted diabetic rats. In another set of experiments, a single dose of the plant aqueous extract (SB, 800 mg/kg p.o.) was used. The hypoglycemic effect of this single dose (SB, 800 mg/kg p.o.) of S. birrea stem-bark aqueous extract was compared with that of chlorpropamide (250 mg/kg p.o.) in both fasted normal and fasted diabetic rats. Following acute treatment, relatively moderate to high doses of S. birrea stem-bark extract (SB, 100-800 mg/kg p.o.) produced dose-dependent, significant reductions (P < 0.05-0.001) in the blood glucose concentrations of both fasted normal and fasted diabetic rats. Chlorpropamide (250 mg/kg p.o.) also produced significant reductions (P < 0.05-0.001) in the blood glucose concentrations of the fasted normal and fasted diabetic rats. Administrations of the single dose of S. birrea stem-bark aqueous extract (SB, 800 mg/kg p.o.) significantly reduced (P 0.01 < 0.001) the blood glucose levels of both fasted normal (normoglycemic) and fasted STZ-treated, diabetic rats. The results of this experimental animal study indicate that aqueous extract of Sclerocarya birrea possesses hypoglycemic activity, and thus lend credence to the suggested folkloric use of the plant in the management and/or control of adult-onset, type-2 diabetes mellitus in some African communities.

Coefficient of failure: a methodology for examining longitudinal beta-cell function in Type 2 diabetes

AIMS

We describe a new method, the determination of the coefficient of failure, which allows the assessment of beta-cell failure from any index of glycaemia. Previous methods using glycaemic thresholds and calculating time-to-failure have systematic deficiencies relating to bias, reproducibility and statistical power. Analyses using threshold methodologies and conventional survival analysis have an intrinsic disadvantage in that they use categorical data and thus make no allowance for near-failure, or progression towards failure. In contrast, the coefficient of failure includes all data in the analysis and takes into account improvement of glycaemia as well as deterioration of glycaemia.

METHODS

We describe the use of a 'coefficient of failure' defined as the slope of the least-squares regression line of a glycaemic index vs. time calculated for each individual patient on constant monotherapy. We exemplify the method using HbA1c levels from data from patients on chlorpropamide (n = 64) or glibenclamide (n = 65) monotherapy in the Oxford cohort of the UKPDS.

RESULTS

Chlorpropamide-treated patients showed a mean coefficient of failure of 0.34 HbA(1c)%/year (0.44%/year sd) and glibenclamide-treated patients 0.50 HbA(1c)%/year (0.50%/year sd) (P = 0.046; unpaired two-tailed t-test). Kolmogorov-Smirnov testing demonstrated that the coefficients did not differ significantly from a normal distribution (chlorpropamide P = 0.12; glibenclamide P = 0.13).

CONCLUSIONS

The coefficient of failure gives an estimate of beta-cell failure using any index of glycaemia. The coefficient is not constrained by predetermined glycaemic thresholds for failure and it allows the rate of decline in beta-cell function to be determined on any therapy or combination of therapies.

Differences in pharmacotherapy and in glucose control of type 2 diabetes patients in two neighbouring towns: a longitudinal population-based study

AIM

To compare prescribing, dosage and blood glucose levels in patients with type 2 diabetes in two communities with differences in anti-hyperglycaemic drug utilization.

METHODS

A retrospective longitudinal (1984-1994) population-based study in two neighbour towns in southern Sweden. The mean prescribed daily dose was expressed as a fraction of the Defined Daily Dose (DDD) for each drug.

RESULTS

In town A, prescribing of oral agents and insulin was predominantly made by one specialized diabetes clinician, while in town B it was spread among several different general practitioners and one specialist. Altogether 44 636 medical visits by 2348 patients were identified. In each town, about 40% of the patients were treated without anti-hyperglycaemic drugs, about 40% with oral agents and about 20% with insulin. However, there were pronounced between-town differences in dosage and glucose control. The mean prescribed daily dose of sulphonylurea monotherapy decreased gradually from approximately 0.7 to approximately 0.5 DDD in town B but remained approximately 0.8 DDD in town A. The proportion of patients on both sulphonylurea and metformin increased substantially in town A but not in town B. In these patients, the mean prescribed daily dose of sulphonylurea exceeded 1.0 DDD in both towns, although it decreased with time in town B. The mean prescribed daily dose of insulin increased from 1.05 to 1.2 DDD in town A but remained virtually unchanged at 0.95 DDD in town B. The mean fasting blood glucose was lower in town A than in town B both overall (7.7 vs. 8.8 mmol/l), in those treated without any anti-hyperglycaemic drugs (7.2 vs. 8.1 mmol/l), in those on sulphonylurea monotherapy (8.3 vs. 9.7 mmol/l) and in those treated with insulin (8.1 vs. 10.2 mmol/l).

CONCLUSIONS

Glucose control in routine care was better when most patients were treated by a diabetes specialist and were exposed to more intense pharmacotherapy.

Sensitivity to sulphonylureas in patients with hepatocyte nuclear factor-1alpha gene mutations: evidence for pharmacogenetics in diabetes

INTRODUCTION

Maturity-onset diabetes of the young (MODY) is characterized by autosomal dominantly inherited, early-onset, non-insulin-dependent diabetes. Mutations in the hepatocyte nuclear factor (HNF)-1alpha gene are the commonest cause of MODY. Individual patients with HNF-1alpha mutations have been reported as being unusually sensitive to the hypoglycaemic effects of sulphonylurea therapy. We report three patients, attending a single clinic, with HNF-1alpha mutations that show marked hypersensitivity to sulphonylureas.

CASE REPORTS

In cases 1 and 2 there were marked changes in HbA1c on cessation (4.4% and 5.8%, respectively) and reintroduction (5.0% and 2.6%) of sulphonylureas. Case 3 had severe hypoglycaemic symptoms on the introduction of sulphonylureas despite poor glycaemic control and was shown with a test dose of 2.5 mg glibenclamide to have symptomatic hypoglycaemia (blood glucose 2 mmol/l) after 4 h despite eating.

CONCLUSIONS

HNF-1alpha MODY diabetic subjects are more sensitive to sulphonylureas than Type 2 diabetic subjects and this is seen in different families, with different mutations and may continue up to 13 years from diagnosis. This is an example of pharmacogenetics, with the underlying aetiological genetic defect altering the pharmacological response to treatment. The present cases suggest that in HNF-1alpha MODY patients: (i) sulphonylureas can dramatically improve glycaemic control and should be considered as initial treatment for patients with poor glycaemic control on an appropriate diet; (ii) hypoglycaemia may complicate the introduction of sulphonylureas and therefore very low doses of short acting sulphonylureas should be used initially; and (iii) cessation of sulphonylureas should be undertaken cautiously as there may be marked deterioration in glycaemic control.

The effect of oral hypoglycaemic agents on dyslipidaemia in Nigerian patients with newly diagnosed non-insulin dependent diabetes mellitus--a prospective study

Thirty-five patients with non-insulin dependent diabetes (NIDDM) were treated and followed up for 24 weeks. Six of whom were managed with diet and/or metformin, nine received glibenclamide, twelve had a combination of metformin and glibenclamide, while the remaining eight patients received metformin and/or some other type of sulphonylurea (chlorpropamide or glipizide). By an analysis of variance, the different drug regimes showed equivalent glycaemic controlling effects, but the influence on dyslipidaemia was variable within the treatment groups, while these changes were insignificant between the groups. It is thus concluded that commonly used oral hypoglycaemic agents do not adversely affect plasma lipid levels in Nigerian patients with NIDDM.

Efficacy of indapamide in central diabetes insipidus

BACKGROUND

Central diabetes insipidus (CDI) results from deficient vasopressin (antidiuretic hormone) secretion and causes polydipsia and polyuria. Desmopressin, a synthetic analog of vasopressin, is the drug of choice in the treatment of CDI, but in mild cases, there are alternative drugs that can be used, including chlorpropamide, carbamazepine, and thiazides.

METHODS

In this study, we investigated the efficacy of treatment with indapamide, which is an antihypertensive diuretic oral agent, in 20 consecutive patients with CDI. The diagnosis of CDI was established by water-deprivation and vasopressin tests. Before the study, serum and urinary osmolality, daily urinary volume, and serum electrolyte levels were measured in all 20 patients. Indapamide (2.5 mg/d) was administered for 10 days, and then the investigations were performed again; for purposes of comparison, 250 mg/d of chlorpropamide was also administered to 11 of the 20 patients who had been given indapamide.

RESULTS

Indapamide revealed a 40.56% +/- 9.70% (mean +/- SD) (range, 19.6%-55.0%) reduction in 24-hour urinary volume and an increase in urinary osmolality, as well as a decrease in serum osmolality, and was as effective as chlorpropamide (P<.05) in the treatment of CDI.

CONCLUSION

Because of its low cost and lack of significant adverse effects, indapamide may be a suitable, easy-to-use alternative oral agent for some patients with CDI.

The antihyperglycamic effect of Telfaria occidentalis in mice

The hypoglycemic effect of Telfaria occidentalis was studied in mice. The effect of the aqueous extract of the leaves on blood glucose level were assessed in normoglycaemic, glucose induced hyperglycaemic and streptozotocin (STZ) induced diabetic mice. The aqueous extract given orally in 1 g/kg did not alter the blood glucose level in normoglycaemic mice. In glucose-induced hyperglycemia, antidiabetic activity was seen when the extract and glucose were administered simultaneously and when the extract was giving to the mice 60 minutes before glucose. In STZ-induced diabetic mice, a reduction in the blood glucose level was seen from day two of the administration of the extract. The hypoglycemic effect of the aqueous extract was compared with that of an oral dose of chlorpropamide (200 mg/kg) under the same conditions. The results of this study indicate that the aqueous extract of the leaves of Telfaria occidentalis possess hypoglycaemic activity.

United Kingdom prospective diabetes study (UKPDS): what now or so what?

The UKPDS was a 20-year study involving 23 centres in the United Kingdom. More than 5000 patients with Type 2 diabetes were recruited. The aim of the study was to determine the impact of intensive blood glucose control on 21 predetermined clinical endpoints using, in the care of blood glucose control, sulphonylureas or insulin therapy or, in the overweight patient, treatment with metformin. In addition, the study investigated the impact of intensive blood pressure control on macro- and microvascular complications of diabetes and compared captopril treatment with atenolol. UKPDS found that improved control of blood glucose or blood pressure reduced the risk of major diabetic eye disease by one quarter, serious deterioration of vision by nearly one half, early kidney damage by one third, strokes by one third, and death from diabetes-related causes by one third. Blood glucose control had little or no effect on macrovascular events. There was no evidence of a major detrimental effect of the drugs or insulin on survival or outcome other than the expected risk of hypoglycaemia. Metformin appeared to be the drug of choice in obese diabetic patients. The targets of glucose and blood pressure control were often achieved by using several drugs. Many patients at the end of the studies were on four or five drugs for blood glucose and blood pressure treatment. The results and implications of the study are discussed. It is proposed that the results of UKPDS herald a new era of more focused therapy of Type 2 diabetes.

Effect of intensive blood-glucose control with metformin on complications in overweight patients with type 2 diabetes (UKPDS 34). UK Prospective Diabetes Study (UKPDS) Group

BACKGROUND

In patients with type 2 diabetes, intensive blood-glucose control with insulin or sulphonylurea therapy decreases progression of microvascular disease and may also reduce the risk of heart attacks. This study investigated whether intensive glucose control with metformin has any specific advantage or disadvantage.

METHODS

Of 4075 patients recruited to UKPDS in 15 centres, 1704 overweight (>120% ideal bodyweight) patients with newly diagnosed type 2 diabetes, mean age 53 years, had raised fasting plasma glucose (FPG; 6.1-15.0 mmol/L) without hyperglycaemic symptoms after 3 months' initial diet. 753 were included in a randomised controlled trial, median duration 10.7 years, of conventional policy, primarily with diet alone (n=411) versus intensive blood-glucose control policy with metformin, aiming for FPG below 6 mmol/L (n=342). A secondary analysis compared the 342 patients allocated metformin with 951 overweight patients allocated intensive blood-glucose control with chlorpropamide (n=265), glibenclamide (n=277), or insulin (n=409). The primary outcome measures were aggregates of any diabetes-related clinical endpoint, diabetes-related death, and all-cause mortality. In a supplementary randomised controlled trial, 537 non-overweight and overweight patients, mean age 59 years, who were already on maximum sulphonylurea therapy but had raised FPG (6.1-15.0 mmol/L) were allocated continuing sulphonylurea therapy alone (n=269) or addition of metformin (n=268).

FINDINGS

Median glycated haemoglobin (HbA1c) was 7.4% in the metformin group compared with 8.0% in the conventional group. Patients allocated metformin, compared with the conventional group, had risk reductions of 32% (95% CI 13-47, p=0.002) for any diabetes-related endpoint, 42% for diabetes-related death (9-63, p=0.017), and 36% for all-cause mortality (9-55, p=0.011). Among patients allocated intensive blood-glucose control, metformin showed a greater effect than chlorpropamide, glibenclamide, or insulin for any diabetes-related endpoint (p=0.0034), all-cause mortality (p=0.021), and stroke (p=0.032). Early addition of metformin in sulphonylurea-treated patients was associated with an increased risk of diabetes-related death (96% increased risk [95% CI 2-275], p=0.039) compared with continued sulphonylurea alone. A combined analysis of the main and supplementary studies showed fewer metformin-allocated patients having diabetes-related endpoints (risk reduction 19% [2-33], p=0.033). Epidemiological assessment of the possible association of death from diabetes-related causes with the concurrent therapy of diabetes in 4416 patients did not show an increased risk in diabetes-related death in patients treated with a combination of sulphonylurea and metformin (risk reduction 5% [-33 to 32], p=0.78).

INTERPRETATION

Since intensive glucose control with metformin appears to decrease the risk of diabetes-related endpoints in overweight diabetic patients, and is associated with less weight gain and fewer hypoglycaemic attacks than are insulin and sulphonylureas, it may be the first-line pharmacological therapy of choice in these patients.

Intensive blood-glucose control with sulphonylureas or insulin compared with conventional treatment and risk of complications in patients with type 2 diabetes (UKPDS 33). UK Prospective Diabetes Study (UKPDS) Group

BACKGROUND

Improved blood-glucose control decreases the progression of diabetic microvascular disease, but the effect on macrovascular complications is unknown. There is concern that sulphonylureas may increase cardiovascular mortality in patients with type 2 diabetes and that high insulin concentrations may enhance atheroma formation. We compared the effects of intensive blood-glucose control with either sulphonylurea or insulin and conventional treatment on the risk of microvascular and macrovascular complications in patients with type 2 diabetes in a randomised controlled trial.

METHODS

3867 newly diagnosed patients with type 2 diabetes, median age 54 years (IQR 48-60 years), who after 3 months' diet treatment had a mean of two fasting plasma glucose (FPG) concentrations of 6.1-15.0 mmol/L were randomly assigned intensive policy with a sulphonylurea (chlorpropamide, glibenclamide, or glipizide) or with insulin, or conventional policy with diet. The aim in the intensive group was FPG less than 6 mmol/L. In the conventional group, the aim was the best achievable FPG with diet alone; drugs were added only if there were hyperglycaemic symptoms or FPG greater than 15 mmol/L. Three aggregate endpoints were used to assess differences between conventional and intensive treatment: any diabetes-related endpoint (sudden death, death from hyperglycaemia or hypoglycaemia, fatal or non-fatal myocardial infarction, angina, heart failure, stroke, renal failure, amputation [of at least one digit], vitreous haemorrhage, retinopathy requiring photocoagulation, blindness in one eye, or cataract extraction); diabetes-related death (death from myocardial infarction, stroke, peripheral vascular disease, renal disease, hyperglycaemia or hypoglycaemia, and sudden death); all-cause mortality. Single clinical endpoints and surrogate subclinical endpoints were also assessed. All analyses were by intention to treat and frequency of hypoglycaemia was also analysed by actual therapy.

FINDINGS

Over 10 years, haemoglobin A1c (HbA1c) was 7.0% (6.2-8.2) in the intensive group compared with 7.9% (6.9-8.8) in the conventional group--an 11% reduction. There was no difference in HbA1c among agents in the intensive group. Compared with the conventional group, the risk in the intensive group was 12% lower (95% CI 1-21, p=0.029) for any diabetes-related endpoint; 10% lower (-11 to 27, p=0.34) for any diabetes-related death; and 6% lower (-10 to 20, p=0.44) for all-cause mortality. Most of the risk reduction in the any diabetes-related aggregate endpoint was due to a 25% risk reduction (7-40, p=0.0099) in microvascular endpoints, including the need for retinal photocoagulation. There was no difference for any of the three aggregate endpoints between the three intensive agents (chlorpropamide, glibenclamide, or insulin). Patients in the intensive group had more hypoglycaemic episodes than those in the conventional group on both types of analysis (both p<0.0001). The rates of major hypoglycaemic episodes per year were 0.7% with conventional treatment, 1.0% with chlorpropamide, 1.4% with glibenclamide, and 1.8% with insulin. Weight gain was significantly higher in the intensive group (mean 2.9 kg) than in the conventional group (p<0.001), and patients assigned insulin had a greater gain in weight (4.0 kg) than those assigned chlorpropamide (2.6 kg) or glibenclamide (1.7 kg).

INTERPRETATION

Intensive blood-glucose control by either sulphonylureas or insulin substantially decreases the risk of microvascular complications, but not macrovascular disease, in patients with type 2 diabetes.(ABSTRACT TRUNCATED)

Effect of intensive blood-glucose control with metformin on complications in overweight patients with type 2 diabetes (UKPDS 34). UK Prospective Diabetes Study (UKPDS) Group

BACKGROUND

In patients with type 2 diabetes, intensive blood-glucose control with insulin or sulphonylurea therapy decreases progression of microvascular disease and may also reduce the risk of heart attacks. This study investigated whether intensive glucose control with metformin has any specific advantage or disadvantage.

METHODS

Of 4075 patients recruited to UKPDS in 15 centres, 1704 overweight (>120% ideal bodyweight) patients with newly diagnosed type 2 diabetes, mean age 53 years, had raised fasting plasma glucose (FPG; 6.1-15.0 mmol/L) without hyperglycaemic symptoms after 3 months' initial diet. 753 were included in a randomised controlled trial, median duration 10.7 years, of conventional policy, primarily with diet alone (n=411) versus intensive blood-glucose control policy with metformin, aiming for FPG below 6 mmol/L (n=342). A secondary analysis compared the 342 patients allocated metformin with 951 overweight patients allocated intensive blood-glucose control with chlorpropamide (n=265), glibenclamide (n=277), or insulin (n=409). The primary outcome measures were aggregates of any diabetes-related clinical endpoint, diabetes-related death, and all-cause mortality. In a supplementary randomised controlled trial, 537 non-overweight and overweight patients, mean age 59 years, who were already on maximum sulphonylurea therapy but had raised FPG (6.1-15.0 mmol/L) were allocated continuing sulphonylurea therapy alone (n=269) or addition of metformin (n=268).

FINDINGS

Median glycated haemoglobin (HbA1c) was 7.4% in the metformin group compared with 8.0% in the conventional group. Patients allocated metformin, compared with the conventional group, had risk reductions of 32% (95% CI 13-47, p=0.002) for any diabetes-related endpoint, 42% for diabetes-related death (9-63, p=0.017), and 36% for all-cause mortality (9-55, p=0.011). Among patients allocated intensive blood-glucose control, metformin showed a greater effect than chlorpropamide, glibenclamide, or insulin for any diabetes-related endpoint (p=0.0034), all-cause mortality (p=0.021), and stroke (p=0.032). Early addition of metformin in sulphonylurea-treated patients was associated with an increased risk of diabetes-related death (96% increased risk [95% CI 2-275], p=0.039) compared with continued sulphonylurea alone. A combined analysis of the main and supplementary studies showed fewer metformin-allocated patients having diabetes-related endpoints (risk reduction 19% [2-33], p=0.033). Epidemiological assessment of the possible association of death from diabetes-related causes with the concurrent therapy of diabetes in 4416 patients did not show an increased risk in diabetes-related death in patients treated with a combination of sulphonylurea and metformin (risk reduction 5% [-33 to 32], p=0.78).

INTERPRETATION

Since intensive glucose control with metformin appears to decrease the risk of diabetes-related endpoints in overweight diabetic patients, and is associated with less weight gain and fewer hypoglycaemic attacks than are insulin and sulphonylureas, it may be the first-line pharmacological therapy of choice in these patients.

Intensive blood-glucose control with sulphonylureas or insulin compared with conventional treatment and risk of complications in patients with type 2 diabetes (UKPDS 33). UK Prospective Diabetes Study (UKPDS) Group

BACKGROUND

Improved blood-glucose control decreases the progression of diabetic microvascular disease, but the effect on macrovascular complications is unknown. There is concern that sulphonylureas may increase cardiovascular mortality in patients with type 2 diabetes and that high insulin concentrations may enhance atheroma formation. We compared the effects of intensive blood-glucose control with either sulphonylurea or insulin and conventional treatment on the risk of microvascular and macrovascular complications in patients with type 2 diabetes in a randomised controlled trial.

METHODS

3867 newly diagnosed patients with type 2 diabetes, median age 54 years (IQR 48-60 years), who after 3 months' diet treatment had a mean of two fasting plasma glucose (FPG) concentrations of 6.1-15.0 mmol/L were randomly assigned intensive policy with a sulphonylurea (chlorpropamide, glibenclamide, or glipizide) or with insulin, or conventional policy with diet. The aim in the intensive group was FPG less than 6 mmol/L. In the conventional group, the aim was the best achievable FPG with diet alone; drugs were added only if there were hyperglycaemic symptoms or FPG greater than 15 mmol/L. Three aggregate endpoints were used to assess differences between conventional and intensive treatment: any diabetes-related endpoint (sudden death, death from hyperglycaemia or hypoglycaemia, fatal or non-fatal myocardial infarction, angina, heart failure, stroke, renal failure, amputation [of at least one digit], vitreous haemorrhage, retinopathy requiring photocoagulation, blindness in one eye, or cataract extraction); diabetes-related death (death from myocardial infarction, stroke, peripheral vascular disease, renal disease, hyperglycaemia or hypoglycaemia, and sudden death); all-cause mortality. Single clinical endpoints and surrogate subclinical endpoints were also assessed. All analyses were by intention to treat and frequency of hypoglycaemia was also analysed by actual therapy.

FINDINGS

Over 10 years, haemoglobin A1c (HbA1c) was 7.0% (6.2-8.2) in the intensive group compared with 7.9% (6.9-8.8) in the conventional group--an 11% reduction. There was no difference in HbA1c among agents in the intensive group. Compared with the conventional group, the risk in the intensive group was 12% lower (95% CI 1-21, p=0.029) for any diabetes-related endpoint; 10% lower (-11 to 27, p=0.34) for any diabetes-related death; and 6% lower (-10 to 20, p=0.44) for all-cause mortality. Most of the risk reduction in the any diabetes-related aggregate endpoint was due to a 25% risk reduction (7-40, p=0.0099) in microvascular endpoints, including the need for retinal photocoagulation. There was no difference for any of the three aggregate endpoints between the three intensive agents (chlorpropamide, glibenclamide, or insulin). Patients in the intensive group had more hypoglycaemic episodes than those in the conventional group on both types of analysis (both p<0.0001). The rates of major hypoglycaemic episodes per year were 0.7% with conventional treatment, 1.0% with chlorpropamide, 1.4% with glibenclamide, and 1.8% with insulin. Weight gain was significantly higher in the intensive group (mean 2.9 kg) than in the conventional group (p<0.001), and patients assigned insulin had a greater gain in weight (4.0 kg) than those assigned chlorpropamide (2.6 kg) or glibenclamide (1.7 kg).

INTERPRETATION

Intensive blood-glucose control by either sulphonylureas or insulin substantially decreases the risk of microvascular complications, but not macrovascular disease, in patients with type 2 diabetes.(ABSTRACT TRUNCATED)

UKPDS 26: Sulphonylurea failure in non-insulin-dependent diabetic patients over six years. UK Prospective Diabetes Study (UKPDS) Group

Patients with Type 2 (non-insulin-dependent) diabetes mellitus (DM) on sulphonylurea therapy convert to insulin progressively as the sulphonylureas 'fail'. The rate of failure and the features of those who fail have been poorly described. To assess secondary failure rates of sulphonylureas, we report on the responses in 1305 patients with newly diagnosed Type 2 DM randomly allocated to therapy with either chlorpropamide or glibenclamide in the UK Prospective Diabetes Study (UKPDS). These patients were initially treated by diet for 3 months and had a fasting plasma glucose > 6 mmol l(-1); mean age 53 (SD 9) years; BMI 26.8 (SD 5.0) kg m(-2); and median fasting plasma glucose 9.1 (7.6-12.5 quartiles) mmol l(-1). If their fasting plasma glucose subsequently rose above 15.0 mmol l(-1), or they developed hyperglycaemic symptoms, additional hypoglycaemic therapy was given: metformin, ultratard insulin, and soluble insulin as required. By 6 years, 44% had required additional therapy. Of those randomized to glibenclamide, 48% required additional therapy by 6 years, compared with 40% of those allocated to chlorpropamide (p < 0.01). Sixty-one per cent, 39%, and 23%, respectively, of patients with fasting plasma glucose > or = 10.0 mmol l(-1), > or = 7.8 mmol l(-1) to < 10.0 mmol l(-1) and < 7.8 mmol l(-1) at randomization required additional therapy (p < 0.001). In the initial 3 years, non-obese subjects (BMI < 30 kg m(-2)) were more likely to require additional therapy than obese patients (BMI > or = 30 kg m(-2)) (43% vs 53% at 6 years; p < 0.001). Modelled beta-cell function showed that those with lower function were more likely to fail (p < 0.0001). Thus sulphonylureas fail as a therapeutic agent at rates which are dependent both on the phenotype at presentation and perhaps on the agent used initially. Higher failure rates were found in those with higher glucose concentrations, those who were younger, those with lower beta-cell reserve and those randomized to glibenclamide compared with chlorpropamide.

UKPDS 28: a randomized trial of efficacy of early addition of metformin in sulfonylurea-treated type 2 diabetes. U.K. Prospective Diabetes Study Group

OBJECTIVE

To assess the efficacy over 3 years of the addition of metformin to maximum sulfonylurea therapy in type 2 diabetes.

RESEARCH DESIGN AND METHODS

This multicenter randomized open-controlled trial was conducted in outpatient diabetes clinics in 15 U.K. hospitals. A total of 591 subjects who had already been randomly allocated to sulfonylurea therapy were taking maximum doses with suboptimal glycemic control, i.e., raised fasting plasma glucose (FPG) concentrations of 6-15 mmol/l but no significant hyperglycemic symptoms. The main outcome measures included FPG, glycated hemoglobin, protocol-defined marked hyperglycemia, body weight, blood pressure, fasting plasma lipids, compliance, and hypoglycemia and other side effects.

RESULTS

After the addition of metformin, FPG concentrations decreased by mean (95% CI) -0.47 (-0.82 to -0.13) mmol/l over 3 years compared with an increase of 0.44 (0.07-0.81) mmol/l in subjects on sulfonylurea alone (P < 0.00001). Median FPG concentrations at 3 years were 8.6 vs. 9.9 mmol/l, respectively (P < 0.00001), and HbA1c values were 7.5 and 8.1%, respectively (P = 0.006). Adjustment for baseline BMI or FPG concentration did not affect response to therapy. Only 7% of those allocated to sulfonylurea plus metformin developed protocol-defined marked hyperglycemia compared with 36% of those allocated to sulfonylurea alone (P < 0.0001). Fasting plasma lipids, body weight, and blood pressure did not change significantly. The incidence of hypoglycemic episodes did not differ between groups: 4% on sulfonylurea plus metformin and 2% on sulfonylurea alone (NS).

CONCLUSIONS

Early addition of metformin improved glycemic control in patients with suboptimal glycemic control while taking maximum sulfonylurea therapy, irrespective of obesity or baseline FPG concentrations.

Auditing prescription practice using explicit criteria and computerized drug benefit claims data

Bringing information on patterns of existing practice together with information on appropriate practice is an essential component of efforts to improve health care. In this study, computerized claims from a universal and comprehensive drug benefit plan for the elderly were brought together with explicit criteria for appropriate prescribing in the elderly in order to provide an estimate of the extent of potentially inappropriate prescribing in the covered population and the degree to which inappropriate prescribing was associated with defined physician characteristics. The analysis showed that 38% of elderly people who received antidepressants, 19% of those who received oral hypoglycemics, 18% of those who received sedative hypnotics and 13% of those who received non-steroidal anti-inflammatory drugs were defined as having received a potentially inappropriate drug. Older physicians and physicians without speciality certification were more likely to prescribe potentially inappropriate drugs. This analysis shows that criteria-based audits of drug claims databases can be used to provide an overview of prescribing problems at a population level and can reveal physician characteristics that may predict poor prescription practice. However, since neither explicit criteria nor claims databases can accurately capture the clinical details that ultimately define the appropriateness of care, audits of claims data should be linked to a more definitive measure of appropriateness and strategies designed to improve care.

Metabolic effects of dietary sucrose and fructose in type II diabetic subjects

OBJECTIVE

To investigate the metabolic effects of dietary fructose and sucrose in type II diabetic patients.

RESEARCH DESIGN AND METHODS

Sixteen well-controlled type II diabetic subjects were fed three isocaloric diets for 28 days each. The three diets provided 50-55, 15, and 30-35% of total energy from carbohydrate, protein, and fat, respectively. In one diet, 20% of total calories were derived from fructose; in another, 19% of total calories were derived from sucrose; and in the control diet, only 5% of daily calories were derived from sugars, all other carbohydrates being supplied as polysaccharides.

RESULTS

No significant differences were observed between either the fructose or the sucrose diet and the control polysaccharide diet in any of the measures of glycemic control, serum lipid levels, or insulin and C-peptide secretion.

CONCLUSIONS

Our data suggest that in the short and middle terms, high fructose and sucrose diets do not adversely affect glycemia, lipemia, or insulin and C-peptide secretion in well-controlled type II diabetic subjects.

United Kingdom Prospective Diabetes Study (UKPDS). 13: Relative efficacy of randomly allocated diet, sulphonylurea, insulin, or metformin in patients with newly diagnosed non-insulin dependent diabetes followed for three years

OBJECTIVE

To assess the relative efficacy of treatments for non-insulin dependent diabetes over three years from diagnosis.

DESIGN

Multicentre, randomised, controlled trial allocating patients to treatment with diet alone or additional chlorpropamide, glibenclamide, insulin, or metformin (if obese) to achieve fasting plasma glucose concentrations < or = 6 mmol/l.

SETTING

Outpatient diabetic clinics in 15 British hospitals.

SUBJECTS

2520 subjects who, after a three month dietary run in period, had fasting plasma glucose concentrations of 6.1-14.9 mmol/l but no hyperglycaemic symptoms.

MAIN OUTCOME MEASURES

Fasting plasma glucose, glycated haemoglobin, and fasting plasma insulin concentrations; body weight; compliance; and hypoglycaemia.

RESULTS

Median fasting plasma glucose concentrations were significantly lower at three years in patients allocated to chlorpropamide, glibenclamide, or insulin rather than diet alone (7.0, 7.6, 7.4, and 9.0 mmol/l respectively; P < 0.001) with lower mean glycated haemoglobin values (6.8%, 6.9%, 7.0%, and 7.6%, respectively; P < 0.001). Mean body weight increased significantly with chlorpropamide, glibenclamide, and insulin but not diet (by 3.5, 4.8, 4.8, and 1.7 kg; P < 0.001). A similar pattern was seen for mean fasting plasma insulin concentration (by 0.9, 1.2, 2.4, and -0.1 mU/l; P < 0.001). In obese subjects metformin was as effective as the other drugs with no change in mean body weight and significant reduction in mean fasting plasma insulin concentration (-2.5 mU/l; P < 0.001). More hypoglycaemic episodes occurred with sulphonylurea or insulin than with diet or metformin.

CONCLUSION

The drugs had similar glucose lowering efficacy, although most patients remained hyperglycaemic. Long term follow up is required to determine the risk-benefit ratio of the glycaemic improvement, side effects, changes in body weight, and plasma insulin concentration.

[Response of insulin and C-peptide to a mixed meal in non-insulin-dependent diabetics treated with insulin and chlorpropamide]

Glucose control in NIDDM is prone to progressive deterioration due to secondary failure to oral hypoglycemic therapy. Insulin may subsequently be required for optimal control in spite of peripheral hyperinsulinemia. In Mexico, diabetes associated with obesity is common. We therefore designed a prospective study combining insulin and chloropropamide in order to evaluate any improvement in insulin response to a standardized meal load and a consequent amelioration of glucose control. METHODS. Twenty diabetic patients with secondary failure to full doses of hypoglycemic drugs and moderate hyperglycemia were recruited. Therapy was initiated with human insulin 20 IU/day and 500 mg cholopropamide, titrating insulin dosage in order to achieve euglycemia. Before treatment and at the end of the study period, a glucose/insulin/C peptide response curve to a mixed standardized meal was performed. Blood glucose, serum lipids fructosamine and glycosylated hemoglobin levels were also determined. All patients were followed by capillary glucose measurements three times a week and glucose and fructosamine concentrations every two weeks during the study period. RESULTS. All patients required less insulin, and glucose control improved significantly. Glucose, fructosamine and glycosylated hemoglobin levels decreased from 262 mg/dL, 369 mmol/L and 14% to 111 mg/dL, 252 mmol/L, and 8% respectively; all differences were statistically significant. Insulin and C peptide levels increased significantly from 22.2 mU/mL and 1.65 ng/mL to 29.8 mU/mL and 1.97 ng/mL, respectively. When we measured the area under the curve, total values improved from 110 and 7.69 to 127 and 9.37, respectively; this was also statistically significant. Lipids levels decreased significantly, including triglicerides, total and LDL cholesterol whereas HDL cholesterol levels increased. CONCLUSIONS. Glucose control improved in our patient cohort the pancreatic insulin response probably due to a more adequate glycemic microenvironment and a possible enhanced exogenous and endogenous insulin function.

Improved metabolic control does not reverse left ventricular filling abnormalities in newly diagnosed non-insulin-dependent diabetes patients

In this study left ventricular diastolic function at rest was evaluated in ten newly diagnosed, non-insulin-dependent diabetic patients by Doppler echocardiography, performed at the onset of disease and after 6 and 12 months of adequate glycaemic control. Glycosylated haemoglobin A1C, total cholesterol and triglyceride levels were assessed at the same time. The control group consisted of ten healthy subjects of matching age and body mass index. The following parameters of left ventricular function were evaluated: ejection fraction (EF), peak velocity of the early (E) and late atrial (A) mitral flow, A/E ratio, duration of the early (Ei) and of the atrial (Ai) filling phase, and heart rate. The diabetic patients had significantly higher total cholesterol and triglyceride levels compared with healthy subjects. These remained elevated throughout the follow-up period, in spite of improved glycaemic control. A significantly shorter duration of Ei (0.15 +/- 0.008 vs 0.18 +/- 0.004, P < 0.01) and a higher value of A (0.51 +/- 0.02 vs 0.39 +/- 0.01, P < 0.001) and A/E (1.06 +/- 0.05 vs 0.73 +/- 0.02, P < 0.001) were found in the diabetic patients before treatment. The parameters did not significantly change after 1 year of adequate glycaemic control. These results indicate a left ventricular filling abnormality which is present in newly diagnosed non-insulin-dependent diabetic patients and does not reverse with improved glycaemic control.

[A comparative evaluation of the hypoglycemic activity of acetyl-alpha-carnitine and chlorpropamide in experimental diabetes]

The comparison of the action shown by acetyl-alpha-carnitine and chloropropamide in rabbits with experimental diabetes has demonstrated that the former has a more pronounced hypoglycemic action. In combined administration, acetyl-alpha-carnitine substantially enhanced the effects of chloropropamide in the animals with experimental diabetes, which should be taken into account by clinicians in its use.

Administration of sulfonylureas can increase glucose-induced insulin secretion for decades in patients with maturity-onset diabetes of the young

OBJECTIVE

To ascertain whether the effect of sulfonylureas on glucose-mediated insulin release persists for years to decades in patients with maturity-onset diabetes of the young.

RESEARCH DESIGN AND METHODS

The effect of sulfonylurea treatment on glucose-induced insulin secretion was ascertained prospectively for up to 33 yr in 12 diabetic patients of the maturity-onset diabetes of the young RW pedigree, who are genetically homogeneous because they share DNA markers on chromosome 20q. In 7 of these patients, paired glucose tolerance tests, given while the patients were on and off sulfonylureas, were performed after 7-31 yr.

RESULTS

Glucose-induced insulin secretion showed an average increase of 68% in diabetic patients who remained responsive to chlorpropamide after having been on and off the drug for decades. In most patients, however, glucose-induced insulin secretion declines over time (1-4%/yr). Some patients become unresponsive to sulfonylureas after 3-25 yr and then have very small or no increases in glucose-induced insulin secretion and require treatment with insulin to normalize fasting hyperglycemia.

CONCLUSIONS

Increase in glucose-induced insulin secretion remains the most important mechanism of the action of sulfonylureas during long-term administration.

Hypertension secondary to chlorpropamide with amelioration by changing to insulin

A retrospective analysis of the records of 22 type II diabetics whose treatment had been changed from insulin to chlorpropamide was performed to investigate the relative effects of insulin and chlorpropamide on blood pressure. Although diastolic BP index was not significantly different between the treatments, systolic BP index was significantly higher on chlorpropamide than on insulin (141 +/- 3 v 135 +/- 3 mm Hg, P = .02). In 10 patients in whom insulin was reinstituted, systolic BP fell significantly (P < .005), suggesting that in type II diabetics chlorpropamide exerts a relative hypertensive effect in comparison to insulin.

Weight loss reverses secondary failure of oral hypoglycaemic agents in obese non-insulin-dependent diabetic patients independently of the duration of the disease

The aim of the present study was to evaluate whether reduction of body weight is able to restore sensitivity to oral hypoglycaemic agents in obese non-insulin-dependent diabetic patients with secondary failure of to the anti-diabetic drugs. 80 obese patients (BMI approximately 30 kg/m2) with Type 2 diabetes lasting 1-30 years and showing hyperglycaemia for at least 3 months (51 on insulin, 29 on oral drugs) received an 800 kcal diet for 20-24 days, lost about 6.3% BMI, and returned to euglycaemia; 22 obese euglycaemic Type 2 diabetes patients (9 on insulin, 13 on oral therapy) underwent the same treatment, and lost approximately 8.3% BMI. As a result insulin could be withdrawn in 18 out of 60 patients and reduced (from 0.5 to 0.2 U.kg day) in the remaining patients. Oral therapy could be withdrawn in 17 out of 42 cases and reduced (from 12.1 to 8.6 mg glibenclamide/day) in the remaining cases. As a control group, 20 non obese (BMI < 24.0 kg/m2) hyperglycaemic Type 2 diabetic patients (10 on oral hypoglycaemic agents, 10 on insulin) with Type 2 diabetes lasting 1-26 years, underwent the same dietary regimen, lost about 3.2% of body weight, but could not withdraw insulin, which had to be started in 6 previously oral hypoglycaemic drugs treated patients. Systolic and diastolic blood pressure and serum cholesterol and triglyceride levels also decreased in obese, but not in non-obese Type 2 diabetes patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of bed time intermediate acting insulin in NIDDM subjects refractory to a combination of sulphonylureas and biguanides

The effect of a single dose of intermediate acting (Lente) insulin given subcutaneously at 9.00 P.M. in 22 NIDDM subjects refractory to a combination of Sulphonylureas and Biguanides was analysed. Euglycemia was achieved and maintained during the study period of three months with a mean insulin requirement of 14.22 +/- 5.98 units/day. Plasma FFA, Total cholesterol, triglyceride and VLDL-cholesterol also showed significant reduction. The level of FFA modulates hepatic glucose production, which in turn correlates positively with the fasting blood glucose. The therapeutic modality of bed time Lente Insulin based on physiological principles is an effective way of achieving glycemic control in NIDDM subjects who have become non-responsive to oral hypoglycemic agents.

Risk factors for hyperinsulinemia in chlorpropamide-treated diabetic patients: a three-year follow-up

To elucidate the presence of chronic hyperinsulinemia and its relation to clinical and biochemical parameters, 112 (53 females and 59 males) Chinese non-insulin-dependent diabetes mellitus (NIDDM) patients under chlorpropamide therapy were closely monitored for three years. Clinical and biochemical risk factors for chronic hyperinsulinemia were studied by regular monitoring of body weight, fasting insulin levels and various biochemical data. Chronic hyperinsulinemia was defined as a mean fasting level over 20 microU/mL (highest level observed in 35 non-diabetics). Among 112 diabetics, 52 cases (46.4%) showed chronic hyperinsulinemia. From simple linear regression analysis, female gender, high BMI and elevated triglyceride and uric acid levels were correlated with insulin levels (p < 0.05). The presence of diabetic complications (retinopathy, neuropathy and nephropathy) and the degree of glycemic control were not significantly different between the normoinsulinemic and hyperinsulinemic groups. In conclusion, 1) NIDDM patients treated with chlorpropamide showed higher fasting insulin levels with 46.4% of them meeting the criteria for chronic hyperinsulinemia; 2) female gender, uric acid, BMI and triglyceride were the risk factors correlated with chronic hyperinsulinemia; and 3) the presence of diabetic complications and diabetic control correlated poorly with chronic hyperinsulinemia.

Is combination sulfonylurea and insulin therapy useful in NIDDM patients? A metaanalysis

OBJECTIVE

To assess the efficacy of combination therapy with insulin and sulfonylurea in the treatment of NIDDM.

RESEARCH DESIGN AND METHODS

Studies published between January 1966 and January 1991 were identified through a computerized Medline search and by hand searching the bibliographies of identified articles. We identified 17 eligible randomized, controlled trials of combination therapy in NIDDM. These trials had a minimum duration of 8 wk and at least one of three outcome measures (fasting glucose, HbA1, or C-peptide) with SD or SE of the mean reported to do metaanalysis. With standardized forms, three independent reviews abstracted measures of study quality and specific descriptive information about population, intervention, and outcome measurements.

RESULTS

We calculated effect size and weighted mean changes of the three outcome measures for control and treatment groups. In the treatment group, the fasting plasma glucose decreased from a mean of 11.4 mM (206 mg/dl) at baseline to a mean of 9.16 mM (165 mg/dl) posttreatment, whereas the control group decreased from (11.3 to 10.8 mM) (204 to 194 mg/dl) (effect size 0.39, P less than 0.0001). For HbA1, the treatment group decreased from a baseline of 11.0 to 10.2% compared to 11.0 and 11.2% in the control group (effect size 0.43, P less than 0.0001). For fasting C-peptide, the treatment group increased from 0.49 to 0.58 nM (1.45 to 1.75 ng/ml) compared with 0.47 and 0.43 (1.42 and 1.30) for the control group (effect size 0.26, P less than 0.017).

CONCLUSION

Combined insulin-sulfonylurea therapy leads to modest improvement in glycemic control compared with insulin therapy alone. With combined therapy, lower insulin doses may be used to achieve similar control. Obese patients with higher fasting C-peptides may be more likely to respond than others.

Combination daytime chlorpropamide-metformin/bedtime insulin in the treatment of secondary failures in non insulin dependent diabetes

OBJECTIVES

To determine the effectiveness of the combination therapy with daytime chlorpropamide-metformin and bedtime NPH insulin in the treatment of secondary failures in NIDDM and to study its effects on insulin secretion.

DESIGN

Non randomized open study with a duration of two months. The patients were followed six months after ending the study.

INSTITUTION

Department of Diabetes and Lipid Metabolism. Instituto Nacional de la Nutrición "Salvador Zubirán", Mexico City. CHARACTERISTICS OF THE PATIENTS: Nine patients (seven women and two men) were included. All had NIDDM and secondary failure to antidiabetic oral drugs. Their fasting plasma glucose was 14.5 +/- 2 mM/L and their HbA1c 13.37 +/- 2.9%. At the entry and at the end of the study a 5h-OGTT was done with assays of plasma glucose and C-peptide.

TREATMENT

Chlorpropamide (375 mg/day) plus metformin (1200 mg/day) and bedtime insulin (0.1 U/kg/day).

RESULTS

After two months on combination therapy, fasting plasma glucose and HbA1c levels were remarkably improved (decreases of 7.3 +/- 0.6 and 9.1 +/- 1.02 respectively, p less than 0.002). The insulin dose was small (6.77 +/- 2.09 U/day). Side effects were minimal and infrequent. During the 5h-OGTT, the mean glucose area under the curve also decreased. The insulin secretion did not change but the C-peptide/glucose ratio increased. At the end of the study, the insulin dose was tapered off and stopped when possible. The four patients with the best glycemic control during the study were able to suspend the bedtime insulin and maintain a good control six months after the insulin suspension.

CONCLUSIONS

The combination therapy is useful in the treatment of secondary failures in NIDDM: Its advantages are the very low mean daily insulin dose needed, the low incidence of side effects and, if a HbA1c less than 8.7% is achieved, the restoration of oral antidiabetic drugs efficacy. The very low insulin dose used in this study could be explained by complementary effects of metformin and bedtime insulin on hepatic glucose output and a putative decrease in peripheral resistance attributable both to sulfonylurea and metformin.

[The efficacy of quercetin in alloxan diabetes]

It has been established that quercetin in doses of 10 and 50 mg/kg promotes normalization of the level of glycemia and blood coagulation, increases liver glycogen content, reduces high blood serum concentrations of cholesterol and low density lipoproteins, seen in diabetes. In some cases, the efficacy of quercetin exceeds that of chlorpropamide and dry Eleutherococcus extract in white rats with alloxan diabetes.

Chlorpropamide induced syndrome of inappropriate secretion of antidiuretic hormone

This is a report of a patient who developed symptomatic hyponatraemia during chlorpropamide therapy for diabetes mellitus. The patient's clinical and biochemical abnormalities were corrected by withdrawal of chlorpropamide. This represents a drug induced, reversible form of the syndrome of inappropriate secretion of antidiuretic hormone (SIADH).

Efficacy of gliclazide in comparison with other sulphonylureas in the treatment of NIDDM

Three studies were performed to assess the efficacy of various sulphonylureas in the management of diet-failed NIDDM patients. In the first study, 224 patients inadequately controlled by diet alone or with oral hypoglycaemics received gliclazide in addition to diet or in place of existing drugs for three months. The dosage was adjusted to obtain adequate control or up to the maximum recommended dosage. Good glycaemic control was achieved in 65% of patients. Conversion from other oral hypoglycaemics to gliclazide led to an improvement in control except in cases previously treated with glibenclamide. In the second study, diabetic control was compared in 112 NIDDM patients treated concurrently for one year with chlorpropamide, glipizide, gliquidone, glibenclamide or gliclazide. On the basis of HbA1 levels, the best results were obtained with glibenclamide and gliclazide, leading to normal HbA1 levels in 74% and 80% of patients, respectively. In the third study, secondary failure rates were assessed in 248 NIDDM patients treated for five years with gliclazide, glibenclamide or glipizide. Gliclazide had the lowest secondary failure rate (7%) and was significantly better than glipizide (25.6% failures in five years), but the difference relative to glibenclamide (17.9%) just failed to reach the threshold of significance. The results of these studies show that gliclazide is a potent hypoglycaemic agent which compares favourably with others of its type. It has a low incidence of side effects, few problems with hypoglycaemia, and retains its efficacy longer than other sulphonylureas. Gliclazide may therefore be considered a first choice for the therapy of diet-failed NIDDM patients.

Effects of lovastatin in diabetic patients treated with chlorpropamide

Patients with non-insulin dependent diabetes mellitus (NIDDM) have a higher risk of atherosclerotic cardiovascular disease than nondiabetic subjects. In seven patients with both hypercholesterolemia and NIDDM controlled by chlorpropamide, lovastatin (20 mg b.i.d. for 6 weeks) lowered low-density lipoprotein cholesterol by 28%, total cholesterol by 24%, and apolipoprotein B by 24%. Lovastatin levels for a 4-hour period (measured as 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitory activity) were similar to those measured previously in nondiabetic patients. Lovastatin did not alter chlorpropamide kinetics or glycemic profiles. No patient had an elevation in serum transaminases or creatinine phosphokinase, and no patient had any other laboratory or clinical drug-related adverse experience during the study. Lovastatin was as effective in reducing low-density lipoprotein cholesterol in patients with NIDDM as in nondiabetic subjects. Diabetic control was unaltered, and no evidence of alteration in lovastatin or chlorpropamide blood levels was noted.

The individual over time: time series applications in health care research

This paper presents a summary and a brief theoretical introduction to time series ARIMA modeling of single subject data. Time series, a statistical technique that may be appropriate when data are measured repeatedly and at nearly equal intervals of time, has potential research applications in the study of chronic diseases such as diabetes, hypertension, and herpes simplex. Both intervention models and multivariate models are covered, with examples illustrating the utility of time series techniques in chronic disease research. Time series modeling of a subject with diabetes before and after being placed on a regimen of chlorpropamide is used to demonstrate the potential of intervention analysis. Multivariate time series techniques are illustrated by modeling the relationship between exercise and blood glucose, and by modelling the relationship between psychosocial distress and lymphocyte subsets of the cellular immune system.

Transient neonatal diabetes mellitus in a pair of twins

The occurrence of transient neonatal diabetes mellitus in male twins with almost identical courses of illness is reported. A trial with chlorpropamide treatment of twin A had no obvious influence on the insulin consumption or on duration of treatment. Very low values of plasma C-peptide and serum proinsulin with no detectable insulin antibodies supports the theory of delayed maturation of the beta-cell.

Prolonged cholestasis and disappearance of interlobular bile ducts following chlorpropamide and erythromycin ethylsuccinate. Case of drug interaction?

A 52-year-old man, having been treated for 4 months with chlorpropamide for diabetes mellitus type II, developed severe cholestatic hepatitis following a short course of erythromycin ethylsuccinate. Despite prompt withdrawal of both drugs, the cholestatic picture worsened and was associated with morphological evidence of disappearing interlobular bile ducts. After a 2-year course of profound cholestasis complicated by steatorrhea and striking hyperlipidemia, the patient died of ischemic cardiomyopathy. It is believed that this is the first published case of irreversible cholestasis with disappearance of ducts potentially related to a metabolic interaction between erythromycin ethylsuccinate and chlorpropamide.

Lactic acidosis due to metformin therapy in a low risk patient

A 55 year old diabetic women treated with chlorpropamide and metformin for three years presented with acute oliguric renal failure and lactic acidosis from which she died. The plasma metformin level was very high suggesting that the lactic acidosis was caused by the drug. There were no contraindications to metformin therapy and renal function was normal three months previously. This case demonstrates that lactic acidosis can occur as a result of metformin therapy in the absence of pre-existing risk factors.

Association of hyperinsulinemia with chlorpropamide toxicity

Clinical and metabolic features of chlorpropamide toxicity are described in two patients with diabetes mellitus and accidental chlorpropamide overdosage. Elevated serum insulin levels were found during hypoglycemia in both patients. The world's literature was reviewed for other cases of chlorpropamide toxicity in which insulin levels have been measured during hypoglycemia. A consistent feature of chlorpropamide toxicity is hyperinsulinemia. It is concluded that stimulation of the pancreatic beta cells during chlorpropamide toxicity leads to hyperinsulinemia and hypoglycemia.

Modification of therapy from insulin to chlorpropamide decreases HDL cholesterol in patients with non-insulin-dependent diabetes mellitus

In 27 patients with non-insulin-dependent diabetes mellitus, we determined fasting serum glucose, hemoglobin A1, body weight, serum triglycerides, cholesterol, low-density lipoprotein cholesterol (LDL-chol), high-density lipoprotein cholesterol (HDL-chol), and very-low-density lipoprotein cholesterol during treatment with insulin and several months after changing treatment to chlorpropamide. In five patients, diabetic control deteriorated to the point where insulin was reinitiated. In the remaining 22 patients, despite a significant decrease in weight (122 +/- 5 vs. 114 +/- 5% ideal body wt; P less than .025) on chlorpropamide, HDL-chol fell from 49 +/- 4 to 40 +/- 4 mg/dl (P less than .01) when therapy was modified from insulin to the sulfonylurea. There was a concomitant increase in LDL-chol:HDL-chol from 3.6 +/- 0.3 to 4.4 +/- 0.5 (P less than .05). In the 5 patients in whom insulin was reinstituted, HDL-chol increased to its previous level on insulin (P less than .05). Changing antidiabetic medication from insulin to sulfonylureas may alter the lipoproteins in a manner that increases cardiovascular risk.

Glyburide and glipizide in treatment of diabetic patients with secondary failures to tolazamide or chlorpropamide

We evaluated therapeutic usefulness of the second-generation sulfonylurea agents glyburide and glipizide in non-insulin-dependent diabetic patients who were secondary failures on chlorpropamide or tolazamide. Twenty patients were treated with glyburide, and 10 of them were subsequently treated with glipizide. Fasting and postprandial serum glucose, insulin, C-peptide, glycosylated hemoglobin, urinary C-peptide, and glucose levels all failed to show significant improvement. We concluded that both glyburide and glipizide proved ineffective in the treatment of secondary failures to first-generation sulfonylureas.