The Combination of Insulin and Metformin in Treatment of Non-Insulin-Dependent Diabetes Mellitus

Use of Continuous Subcutaneous Insulin Infusion Pump in Patients With Type 2 Diabetes Mellitus

Purpose

In patients with type 2 diabetes, the control of hyperglycemia is often difficult despite full doses of oral hypoglycemic agents and extremely large doses of insulin. These patients pose a major management problem. The authors therefore investigated whether insulin given as a subcutaneous continuous infusion of insulin (CSII) would result in an improvement in glucose homeostasis.

Methods

Four patients with badly controlled type 2 diabetes, on treatment with extremely high doses of insulin and oral hypoglycemic agents, were started on CSII.

Results

All four patients had a marked improvement in plasma glucose concentrations with a corresponding fall in HbA1c levels. This improvement was associated with a marked fall in the insulin doses necessary to maintain adequate glucose homeostasis.

Conclusions

Since HbA1c levels fell from levels that would be associated with diabetic complications to those at which complications are markedly reduced, we recommend that patients with type 2 diabetes uncontrolled on extremely high doses of insulin be given a trial of treatment with CSII.

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.

Is beta-cell failure in type 2 diabetes mellitus reversible?

BACKGROUND:

In the UK Prospective Diabetes Study (UKPDS), many subjects maintained glycemic goal (HbA_1c < 7.0%) at 9 years, showing that β-cell function was preserved and that the initial decline in β-cell function recovered with sulphonylureas. Moreover, obese subjects using high daily doses of insulin for several years rarely require insulin or oral hypoglycemic agents to maintain their glycemic goal following weight loss achieved by gastric bypass surgery. Thus, declining β-cell function during the course of type 2 diabetes mellitus (T2DM) is neither universal nor permanent.

OBJECTIVE:

To assess β-cell function in morbidly obese subjects before insulin withdrawal and on attaining the glycemic goal with weight loss and oral agents.

MATERIALS AND METHODS:

Serum C-peptide (CPEP) and glucose (G) concentrations were determined up to 180 min during an oral glucose tolerance test (OGTT) with 75 glucose in 10 obese men with T2DM, before insulin withdrawal, and on achieving the glycemic goal with metformin, glimepiride, and weight loss. Ten age-matched healthy men participated as controls. Cumulative responses (CR) of CPEP and G were calculated by adding differences between the level at each time-period during OGTT and fasting (F) concentration. β-Cell function was expressed as the FCPEP as well as the insulinogenic index (CRCPEP/CRG). Insulin sensitivity was determined as FCEP × FG.

RESULTS:

FCPEP was decreased, though still present, prior to insulin withdrawal. Moreover, on attaining the glycemic goal over 6-9 months, FCPEP, CRPEP/CRG, and FCPEP × FG improved markedly (P < 0.001).

CONCLUSION:

Decline in β-cell function in morbidly obese T2DM may not be progressive and is reversible on improving insulin sensitivity and on eliminating the inhibition by exogenous insulin.

Metabolic syndrome and type 2 diabetes: can we stop the weight gain with diabetes?

Many patients with type 2 diabetes also have the metabolic syndrome with its cardinal features of central adiposity, insulin resistance, dyslipidemia, and hypertension. Although there is strong evidence for the importance of tight glycemic control in minimizing the microvascular complications of diabetes, many of the current therapies used for optimizing glycemic control also cause weight gain. With this treatment-induced weight gain, there is a risk of worsening the patient's insulin resistance. Physicians need to be aware of this vicious cycle in their overweight type 2 diabetic patients. This article reviews the strategies currently available to achieve glycemic control while at the same time minimizing weight gain and the associated complications.

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.

Primary, secondary, tertiary, and quaternary treatment with troglitazone in type 2 diabetes mellitus in an outpatient clinical practice

OBJECTIVE

To assess the value of troglitazone in various combinations of therapy with sulfonylureas, biguanides, and insulin, including triple oral agent therapy with and without insulin, in an outpatient clinical practice.

METHODS

We compiled results in our first 207 patients with type 2 diabetes treated for 1 year with troglitazone. In eight study groups, troglitazone was added to the following prior regimens: (1) diet alone, (2) sulfonylurea, (3) metformin, (4) sulfonylurea and metformin, (5) insulin, (6) insulin and sulfonylurea, (7) insulin and metformin, and (8) insulin, sulfonylurea, and metformin. Glycosylated hemoglobin, fasting plasma glucose, hemoglobin, weight, and insulin dose were recorded every 3 months for 1 year and are reported.

RESULTS

The glycosylated hemoglobin decreased in all study groups during the 1-year period. With the addition of troglitazone, it declined from 8.0% to 6.0% in the diet-only treatment group, from 8.9% to 7.3% in the sulfonylurea group, from 8.4% to 7.2% in the metformin group, and from 8.6% to 7.5% in the group treated with sulfonylurea and metformin. For the groups receiving insulin, glycosylated hemoglobin decreased in conjunction with a significant decline in insulin dose. The dose of insulin was reduced from a baseline of 62 to 41 U per patient in the insulin-only treatment group, from 36 to 12 U per patient in the group treated with insulin and sulfonylurea, and from 28 to 11 U per patient in the group treated with insulin and metformin. In the group treated with insulin, sulfonylurea, and metformin, the dose of insulin was decreased from 36 to 13 U.

CONCLUSION

From our data in more than 200 patients with type 2 diabetes, who participated in a 1-year follow-up in an outpatient clinical practice, we found that troglitazone improved glycemic control in each study group and also decreased the insulin dose in the insulin-requiring patients. Troglitazone improves glycemic control as a primary, secondary, tertiary, or even quaternary therapy in patients with type 2 diabetes.