Low-dose bedtime NPH insulin in treatment of secondary failure to glyburide

Efficacy of Sulfonylureas with Insulin in Type 2 Diabetes Mellitus

BACKGROUND:

In subjects with type 2 diabetes mellitus, glycemic control deteroriates while patients use sulfonylurea drugs during the course of the disease. Adjunctive therapy with insulin at this stage requires a lesser daily insulin dose in comparison with insulin monotherapy while restoring desirable glycemic control. However, data regarding direct comparison between various sulfonylureas in this regard are lacking.

OBJECTIVE:

To examine comparative efficacies of adjunctive therapy with insulin in subjects with type 2 diabetes manifesting lapse of glycemic control while receiving various individual sulfonylurea drugs.

METHODS:

Four groups of 10 subjects, each presenting with glycosylated hemoglobin (HbA1C) >8.0% while using either tolazamide, glyburide, glipizide Gastrointestinal Therapeutic System (GITS), or glimepiride, were recruited. Two from each group were randomized to receive placebo; the others continued the same drug. Pre-supper subcutaneous 70 NPH/30 regular insulin was initiated at 10 units and gradually increased and adjusted as necessary to attain fasting blood glucose levels between 80 and 120 mg/dL and maintain the same range for 6 months. Fasting plasma glucose, plasma C-peptide, and HbA1C concentrations were determined prior to the addition of insulin and at the end of the study. Daily insulin dose and changes in body weight (BW) were noted at the end of the study, and the number of hypoglycemic events during the last 4 weeks of the study was determined.

RESULTS:

Daily insulin dose (units/kg BW), weight gain, and number of hypoglycemic events were significantly lower (p < 0.01) in subjects receiving sulfonylureas in comparison with placebo. However, the daily insulin dose alone was significantly lower (p < 0.05) with glimepiride (0.49 ± 0.10; mean ± SE) than with other sulfonylureas (tolazamide 0.58 ± 0.12, glyburide 0.59 ± 0.12, glipizide GITS 0.59 ± 0.14). Finally, a significant correlation (r = 0.68; p < 0.001) was noted between suppression of plasma C-peptide level and the daily insulin dose among all participants.

CONCLUSIONS:

By lowering the daily insulin dose, sulfonylurea drugs appear to improve the sensitivity of exogenous insulin in subjects with type 2 diabetes mellitus manifesting lapse of glycemic control. Moreover, glimepiride appears to possess a greater insulin-sparing property than other sulfonylureas.

Comparative efficacy of glimepiride and/or metformin with insulin in type 2 diabetes

BACKGROUND AND AIMS

The data regarding comparison of efficacy of metformin with glimepiride, newest Sulfonylurea, or with the use of both drugs in combination with insulin is rare in the literature. Therefore, we assessed the daily insulin dose, hypoglycemic events and body weight on achieving desirable glycemic control after addition of insulin, to glimepiride 8 mg and/or metformin 2500 mg, in subjects with type 2 DM manifesting lapse of glycemic control.

METHODS

S.C. insulin Novolog Mix [70/30], pre-supper was initiated in 12 subjects on metformin, 14 subjects on glimepiride, and 12 subjects receiving both drugs, with HbA1C > 7.5% and eight subjects receiving placebo. Insulin dose was increased by 4 U at weekly interval until fasting blood sugar [FBS] between 6.6 and 8 mM/l was attained and then further titrated by 2 U every week to attain and maintain FBS between 4.5 and 6.7 mM/l over the next 4 months. The comparisons were conducted between these groups for HbA1C, the daily insulin dose, body weight noted at the end of this study period as well as the hypoglycemic episodes per patient during the last 4 weeks of the study period.

RESULTS

HbA1C levels were < 7.0% in all subjects at the end of the study. The daily insulin dose (units), total and per kg/BW was significantly lower [p < 0.001] with metformin (51 +/- 5, 0.51 +/- 0.10), glimepiride (40 +/- 4, 0.42 +/- 0.09) as well as with both drugs (23 +/- 7, 0.21 +/- 0.07) in comparison to placebo (82 +/- 10, 0.82 +/- 0.12). The insulin dose was also significantly lower [p < 0.05] in subjects on both drugs than subjects receiving them individually. Weight gain was less [p < 0.001] with metformin [2.5 +/- 0.74 kg], glimepiride [2.3 +/- 0.7 kg], and both drugs [2.2 +/- 0.61 kg] in comparison to placebo [5.2 +/- 1.4 kg] whereas the hypoglycemic episodes were lesser with metformin (3.8 +/- 1.2) and glimepiride (3.3 +/- 0.9) and least with both drugs (2.5 +/- 0.6) in comparison to placebo (5.2 +/- 1.0).

CONCLUSION

Glimepiride and metformin are effective individually in achieving a glycemic goal with a less daily insulin dose, weight gain, and hypoglycemic episodes in comparison to insulin monotherapy in subjects with type 2 diabetes mellitus with further marked reduction in these parameters when used concurrently.

Diabetes mellitus and pharmacological therapy

Diabetes mellitus can be a devastating lifelong disease if not treated appropriately. The physician and the patient should be aware of both extremes involved with DM: hyperglycemia and hypoglycemia. Patient education and preventive care are perhaps more important in this disease than many others. A multidisciplinary approach involving the patient, physician, and diabetic educator is best to assure a better quality of life. Enormous advances in the treatment of diabetes have occurred over the past decade and even greater ones can be expected in the future. New drugs, insulin delivery devices, and noninvasive glucose monitoring machines have the potential to normalize blood sugar levels and return diabetics to a near normal lifespan without complications.

Insulin lispro in the treatment of patients with type 2 diabetes mellitus after oral agent failure

This study assessed the safety profile and efficacy of a new combination therapy (insulin lispro plus sulfonylurea) in patients with type 2 diabetes mellitus experiencing secondary oral agent failure. A total of 423 patients were randomly assigned to 3 treatment groups: preprandial insulin lispro plus sulfonylurea (L + S), bedtime neutral protamine Hagedorn (NPH) insulin plus sulfonylurea (N + S), and preprandial insulin lispro plus bedtime NPH insulin (L + N). Mean decreases in glycosylated hemoglobin from baseline were 1.60%+/-1.27% for patients receiving L + S, 1.21%+/-1.21% for those receiving N + S, and 1.40%+/-1.46% for those receiving L + N (within treatment, P<0.001; for L + S vs. N + S, P = 0.003). Fasting blood glucose level was higher in patients receiving L + S (171+/-46.5 mg/dL) or L + N (166+/-52.5 mg/dL) than in those receiving N + S (144+/-48.2 mg/dL) (P<0.001, for both comparisons). Conversely, postprandial blood glucose level was lower in patients receiving L + S (165+/-41.6 mg/dL) or L + N (165+/-46.3 mg/dL) than in those receiving N + S (213+/-58.3 mg/dL) (P<0.001, for both comparisons). The overall rate of hypoglycemia (episodes per 30 days) was not statistically significant when the L + S, N + S, and L + N therapies were compared (0.99+/-1.74 vs. 0.87+/-2.31 vs. 1.16+/-2.38, respectively). The rate of nocturnal hypoglycemia was lowest in the L + S group (0.00+/-0.00 vs. 0.10+/-0.37 for the N + S group vs. 0.15+/-0.54 for the L + N group; P = 0.004). L + S, which has a safety profile equal to those of N + S and L + N, is an effective treatment for patients with type 2 diabetes who experience oral sulfonylurea agent failure. L + S offers an alternative to these established combination therapies in patients whose type 2 diabetes cannot be controlled with a sulfonylurea alone.

Acarbose vs. bedtime NPH insulin in the treatment of secondary failures to sulphonylurea-metformin therapy in type 2 diabetes mellitus

OBJECTIVE

To evaluate the efficacy of acarbose in the treatment of secondary failures to sulphonylurea-metformin therapy, its comparison against bedtime NPH insulin, and to measure the changes in postprandial metabolism resulting from both treatments.

METHODS

One hundred type 2 diabetic patients in a secondary failure were included. The study begun with a run-in diet period of 6 weeks, in which an isocaloric diet was prescribed. Only subjects who continued hyperglycaemic were randomly assigned to placebo and acarbose (n = 17) or bedtime NPH insulin (n = 12). Acarbose (300 mg/day) or placebo were administered using a randomized, double blind, crossover design. Treatment periods of 3 months were separated by a 3-week washout period. Insulin was administered during 3 months. At the beginning and the end of each treatment period, an i.v. glucose tolerance test and a meal test were performed. Safety tests were done every 4 weeks.

RESULTS

Acarbose resulted in a small but significant improvement in fasting plasma glucose (13.5 +/- 2.4 vs. 11.3 +/- 3.9 mmol/l, p = 0.05), HbA1c (11.1 +/- 3.4 vs. 10.3 +/- 2.5%, P = 0.3) and in a decreased plasma glucose during the meal test. Bedtime insulin significantly decreased fasting plasma glucose (13.1 +/- 2.9 vs. 8.2 +/- 2.3 mmol/l, p < 0.01), HbA1c (11.7 +/- 2.9 vs. 9.4 +/- 2.7%, p < 0.01) and plasma cholesterol. No change in insulin secretion resulted from insulin and acarbose treatment.

CONCLUSIONS

Acarbose decreases blood glucose in secondary failure to sulphonylurea-metformin therapy; however, the decrease is not enough to reach the desired metabolic control. Bedtime NPH insulin is, by far, a more effective alternative.

Oral antidiabetic drug use in the elderly

Non-insulin-dependent diabetes mellitus (NIDDM) is a metabolic disease that is common in the elderly, and is characterised by insulin insufficiency and resistance. Measures such as bodyweight reduction and exercise improve the metabolic defects, but pharmacological therapy is the most frequently used and successful therapy. The sulphonylureas stimulate insulin secretion. Metformin and troglitazone increase glucose disposal and decrease hepatic glucose output without causing hypoglycaemia. Acarbose is a dietary aid that spreads the dietary carbohydrate challenge to endogenous insulin over time. These pharmacological agents, either alone or in combination, should improve blood glucose regulation in patients with NIDDM.

Inappropriate use of high-dose glyburide to treat uncontrolled type 2 diabetes mellitus

OBJECTIVE

To report a case of chronic glyburide overdose.

CASE SUMMARY

A patient with noninsulin-dependent diabetes mellitus (NIDDM) who had previously developed secondary failure while taking a maximal dosage of glipizide was switched to glyburide 5 mg/d. The patient initially experienced adequate glycemic control while taking glyburide, but subsequently experienced deterioration in glycemic control. This necessitated gradual increases in the dosage of glyburide until the maximum dosage of 20 mg/d was reached. Because the patient's diabetic control did not improve with this dosage of glyburide, she decided independently to increase the dosage further. She ingested an average daily dose of 37.7 mg of glyburide over the 18 days that preceded her clinic visit without experiencing any glyburide-related adverse effects.

DISCUSSION

Progression of NIDDM may be responsible for the development of secondary sulfonylurea failure in NIDDM patients treated with oral sulfonylurea drugs. Consequently, these patients should be treated as patients dependent on insulin.

CONCLUSIONS

NIDDM patients treated with oral sulfonylurea drugs require long-term blood glucose monitoring to detect the development of secondary sulfonylurea failure. Patients who experience secondary failure to a particular sulfonylurea drug do not appear to develop long-term blood glucose control when switched to a different oral sulfonylurea drug. These patients should be treated with insulin therapy.

Morning versus bedtime isophane insulin in type 2 (non-insulin dependent) diabetes mellitus

Morning versus bedtime administration of NPH insulin was compared in 12 subjects with Type 2 diabetes and overt fasting hyperglycaemia. Subjects were studied at baseline (diet alone) and after 2 months on each of the two insulin programmes in a random crossover design, in which dosage was increased until at least one daily preprandial blood glucose was consistently in the range of 3.9 to 6.0 mmol l-1. Mean (+/- SEM) daily total insulin dosage was equivalent for the morning (0.36 +/- 0.03 units kg-1) and for the bedtime (0.37 +/- 0.03 units kg-1) insulin administration schedules. Glycaemic control was improved on both insulin regimens, but was better on bedtime than morning insulin. Fasting plasma glucose (mmol l-1) was 12.0 +/- 0.7 (baseline), 8.6 +/- 0.7 (morning), and 4.6 +/- 0.3 (bedtime), respectively. Mean 24 h plasma glucose (mmol l-1) was 13.3 +/- 1.3, 9.0 +/- 0.7, and 7.8 +/- 0.7. Glycated haemoglobin (%) was 7.65 +/- 0.35, 6.23 +/- 0.26, and 5.81 +/- 0.32. The improvement of basal glycaemia is a consequence of increased basal metabolic clearance of glucose (baseline, 47.6 +/- 3.1 ml m-2 min-1; morning 63.5 +/- 5.4, bedtime 103.5 +/- 7.1). There was no change in hepatic glucose output. It is concluded that bedtime administration of intermediate acting insulin results in increased basal insulinaemia, leading to improved basal glycaemia and consequent improved overall metabolic control, compared to morning insulin administration. Therefore, bedtime may be the preferable timing of insulin therapy for patients with Type 2 diabetes and overt fasting hyperglycaemia.

Effects of the combination of insulin and gliclazide compared with insulin alone in type 2 diabetic patients with secondary failure to oral hypoglycemic agents

Twenty non-insulin-dependent diabetic patients on insulin therapy for more than 2 months due to secondary failure to oral hypoglycemic agents (OHA) were additionally treated with gliclazide, 80 mg b.i.d., for 1 month and 160 mg b.i.d. for a further 2 months, while reducing insulin dose gradually according to glycemic control. At the end of the first month, fasting blood glucose had decreased from 12.8 +/- 0.7 to 9 +/- 0.8 mM (mean +/- standard error; P < 0.005) and thereafter remained stable. Insulin requirements decreased from 34.2 +/- 2.5 to 18.3 +/- 3.2 U/day (P < 0.001). Three patients were able to cease insulin treatment altogether. A direct correlation was found between final insulin dose and previous duration of infusion monotherapy (r = 0.52; P < 0.05). C-peptide/glucose score (fasting C-peptide/fasting BG x 100) increased from 0.11 +/- 0.03 to 0.21 +/- 0.05 (P < 0.05). We conclude that combined therapy reduces insulin requirement by increasing endogenous secretion, which may mainly affect hepatic glucose production as indicated by greater improvement in fasting vs. post-prandial blood glucose. This therapy could avoid hyperinsulinemia, which has been reported to be involved in macrovascular complications, and the additional haemovascular properties of gliclazide could make it more effective in such a combination.

Combining insulin and sulfonylurea. A therapeutic option for type II diabetes

Non-insulin-dependent (type II) diabetes mellitus is a progressive disease that requires sequential therapy to achieve optimal control. When diet and sulfonylurea fail to maintain glycemic control, the addition of a single daily injection of insulin may be indicated. The best candidates for this combined therapy are patients with typical adult-onset disease that has been present less than 10 to 15 years.

One-year response to evening insulin therapy in non-insulin-dependent diabetes

We studied the 1-year response and predictors of the response to combination therapy with evening insulin and oral agents in NIDDM patients with a secondary failure. Injection of intermediate-acting (Monotard HM) or long-acting (Ultratard HM) insulin was added to previous oral therapy in 17 diabetics (of mean age (+/- SD) 54 +/- 2 years, BMI 27.6 +/- 0.5 kg m-2). The initial insulin dose was in the range 10-16 U, and the mean dose was 23 +/- 2 U d-1 at 12 months. During the year, combination therapy reduced the mean fasting blood glucose concentration (12.7 +/- 0.6 vs. 8.4 +/- 0.7 mmol l-1, P less than 0.001) and HbA1 (10.7 +/- 0.3 vs. 9.8 +/- 0.4%, P less than 0.01). Body weight increased by 4.4 +/- 0.7 kg (P less than 0.001). The serum cholesterol concentration decreased by 14% (P less than 0.01), but serum triglyceride and HDL-cholesterol levels remained unchanged. Elevation of serum triglycerides and plasma free fatty acids (FFAs) at baseline predicted a poor long-term outcome to this mode of therapy. In conclusion, the addition of evening injections of insulin to oral therapy improves glycaemic control in poorly controlled NIDDM patients. However, initial hypertriglyceridaemia predicts a poor long-term outcome to evening insulin supplementation.

Combined therapy for obese type 2 diabetes: suppertime mixed insulin with daytime sulfonylurea

Combined insulin and sulfonylurea therapy for type 2 diabetes may improve the effectiveness of a single injection of insulin, thereby postponing the need for multiple injections. This concept was tested in 21 obese subjects imperfectly controlled by 20 mg of glyburide daily in a double masked, placebo-controlled, parallel design, 16-week protocol. Premixed 70% NPH/30% Regular insulin was taken before supper, and the dosage was adjusted weekly by an algorithm seeking nearly normal fasting glycemia. Eleven subjects using insulin plus 10 mg glyburide before breakfast had lower mean fasting glucose at 10-16 weeks than 10 subjects using insulin with placebo (mean +/- SEM; 5.9 +/- 0.3 versus 7.5 +/- 0.7 mmol/L; p less than 0.05), and had a greater decrement of glycosylated hemoglobin from baseline values (1.3 +/- 0.1 versus 0.8 +/- 0.2% A1, p less than 0.05). After 16 weeks the combined therapy group used half as much insulin as the insulin-only group (50 +/- 5 versus 101 +/- 13 units/d; p less than 0.01). Fasting serum free insulin values increased 58% from baseline after insulin therapy in the insulin-only group (p less than 0.05) but did not increase with combined therapy. Weight gain was similar in the two groups. These data support this form of combined therapy as one option for treating obese persons with type 2 diabetes no longer responsive to oral therapy alone.

Insulin therapy in maturity-onset diabetes

A prime target of insulin action in patients with maturity onset diabetes is suppression of hepatic glucose production in both the fasting and postprandial states. In patients who fail to respond to oral treatment insulin improves glycaemic control, has an antiatherogenic effect on the serum lipoprotein pattern, and increases well being. The beneficial long-term effects of insulin therapy on morbidity and mortality are, however, still unproved. The regimens of insulin therapy are not established. In patients with normal or increased basal serum C-peptide concentration treatment may start with intermediate or long-acting insulin at bedtime together with oral medication, or in the morning with or without oral medication. If this fails two injections of intermediate-acting insulin or multiple injections of short-acting insulin should be started. Hypoglycaemia is uncommon in maturity onset diabetes treated with insulin, but moderate weight gain usually occurs. The possible role of hyperinsulinemia as a predisposing factor for atherogenesis remains unresolved. Despite controversies over treatment, any patient with maturity onset diabetes not responding to oral agents should be regarded as a candidate for insulin therapy.

Advances in the management of diabetes mellitus

This article shall highlight several areas where recent developments have made, and may make in the future, practical advances to diabetes care. These advances have been in the areas of insulin therapy, glucose monitoring, identifying pre-diabetics and using immunosuppressive agents in pre-diabetes and early diabetes, pancreatic transplantation, and managing acute and chronic complications of diabetes.