Premeal insulin lispro plus bedtime NPH or twice-daily NPH in patients with type 2 diabetes: acute postprandial and chronic effects on glycemic control and cardiovascular risk factors

Effects of insulin analogs as an add-on to metformin on cutaneous microcirculation in type 2 diabetic patients

BACKGROUND

A single insulin injection was shown to improve microcirculatory blood flow. Our aim was to examine the effects of 4weeks of insulin therapy by three randomly assigned insulin analog regimens (Detemir, Aspart, and their combination) on cutaneous blood flow (CBF) and microcirculatory endothelial function as an add-on to metformin in type 2 diabetic patients poorly controlled on oral antidiabetic treatment.

METHODS

Fourty-two type 2 diabetic patients with no history of cardiovascular disease in secondary failure to oral antidiabetic agents had CBF measurements before and after acetylcholine (Ach) iontophoretic administration. CBF measurements were performed at fasting and after a standardized breakfast during the post-prandial period. Before randomization (Visit 1, V1) during the tests, participants took only metformin. The same tests were repeated after 4weeks of insulin treatment (Visit 2, V2).

RESULTS

Thirty-four patients had good quality recordings for both visits. During V1, CBF and CBF response to Ach increased in the post-prandial period. After 4weeks of insulin treatment, metabolic parameters improved. Compared to V1, CBF at fasting did not increase at V2 but there was an improvement in endothelial function at fasting after Ach iontophoresis, without difference across insulin regimens. Oxidative stress markers were not modified, and E-selectin and vascular cell adhesion molecule 1 levels decreased after insulin treatment, without differences between insulin groups.

CONCLUSIONS

A strategy of improving glycemic control for 4weeks with insulin analogs improves microcirculatory endothelial reactivity and reduces endothelial biomarkers at fasting, whatever the insulin regimen used. Insulin therapy associated to metformin is able to improve fasting microvascular endothelial function even before complete metabolic control.

Rationale for treatment options for mealtime glucose control in patients with type 2 diabetes

While glycemic control is routinely assessed using HbA1c and fasting glucose measures, postprandial glucose (PPG) is also an important contributor of overall glycemia. Furthermore, PPG excursions have been linked to complications of diabetes. This review examines the effects of glucose-lowering therapies (including treatments administered at mealtime) on postprandial hyperglycemia in patients with type 2 diabetes. A PubMed search was conducted to identify clinical studies of treatments for mealtime glucose control in type 2 diabetes. Different treatments may have comparable effects on HbA1c but varying effects on PPG control and glucose fluctuations. Older classes of oral glucose-lowering treatments administered at mealtime to lower PPG include meglitinides and α-glucosidase inhibitors. Injectable therapies, including prandial insulin analogs, glucagon-like peptide-1 receptor agonists (GLP-1RAs), and the amylin analog pramlintide, all effectively target postprandial hyperglycemia. Compared with longer-acting GLP-1RAs, short-acting GLP-1RAs, such as exenatide twice daily and lixisenatide once daily, have a greater effect on PPG control, which is primarily mediated by a more pronounced effect on delayed gastric emptying. Dipeptidyl peptidase-4 inhibitors and sodium-glucose cotransporter 2 inhibitors also reduce postprandial hyperglycemia. To achieve more physiologically normal glycemic control, choice of therapy should ideally aim to address daily glucose fluctuations, including hyperglycemic peaks and hypoglycemic troughs, and long-term glycemic control.

Efficacy and safety of insulin lispro in geriatric patients with type 2 diabetes: a retrospective analysis of seven randomized controlled clinical trials

Background and Aims

Glycemic control in geriatric patients with type 2 diabetes (T2DM) remains clinically challenging. The objective of this study was to compare the safety and efficacy of insulin lispro in patients ≥65 years (geriatric) to those <65 years (non-geriatric), using a meta-analysis of randomized controlled clinical trials (RCT).

Methods

This is a retrospective analysis of predefined endpoints from an integrated database of seven RCTs of T2DM patients treated with insulin lispro. The primary efficacy measure tested the non-inferiority of insulin lispro (geriatric vs. non-geriatric; non-inferiority margin 0.4 %) in terms of hemoglobin A_1c (HbA_1c) change from baseline to Month 3 (N = 1,525), with change from baseline to Month 6 as a supportive analysis (N = 885). Changes in HbA_1c from baseline were evaluated with an analysis of covariance model. Secondary measures included incidence and rate of hypoglycemia, and incidence of cardiovascular events.

Results

Mean change in HbA_1c from baseline to Month 3 was similar for geriatric (−0.97 %) and non-geriatric patients (−1.05 %); least-square (LS) mean difference (95 % CI) was 0.02 % (−0.11, 0.15 %; p = 0.756). Similar results were observed in patients treated up to Month 6; LS mean difference (95 % CI) was 0.07 % (−0.12, 0.26 %; p = 0.490). Decrease in HbA_1c from baseline to Months 3 and 6 was non-inferior in geriatric compared with non-geriatric patients. There were no significant differences in the incidence and the rate of hypoglycemia, incidence of cardiovascular events, or other serious adverse events including malignancy, post-baseline between the two cohorts.

Conclusion

Key measures of efficacy and safety in geriatric patients with T2DM were not significantly different from non-geriatric patients when utilizing insulin lispro. Insulin lispro may be considered a safe and efficacious therapeutic option for the management of T2DM in geriatric patients.

Metabolic control and risk of hypoglycaemia during the first year of intensive insulin treatment in type 2 diabetes: systematic review and meta-analysis

AIM

Aim of this study was to analyse clinical correlates of HbA1c, and of overall, nocturnal, and severe hypoglycaemia, through direct-weighted regressions, as well as the effect of different insulin regimens and insulin analogues, through meta-analysis.

METHODS

Appropriate methodology (PRISMA statement) was used. Sixty-seven randomized studies, published as full papers were analysed to identify predictors of both HbA1c and hypoglycaemia; studies were included in a meta-analysis to study the effect of different insulin regimens or insulin analogues on HbA1c and hypoglycaemia during the first year of insulin treatment in type 2 diabetes patients.

RESULTS

Final HbA1c, change of HbA1c, hypoglycaemia, nocturnal hypoglycaemia and severe hypoglycaemia were associated with intensity of treatment. Final HbA1c was higher with basal than with twice-a-day or prandial, and with twice-a-day than with prandial regimen, with opposite figures for hypoglycaemia. Within basal regimens, detemir and glargine were similar to NPH insulin on HbA1c, with less hypoglycaemia and nocturnal hypoglycaemia; within prandial regimens, new analogues were more effective than regular insulin on HbA1c, and induced less hypoglycaemia. The effect of glargine on HbA1c and on hypoglycaemia vanished with increasing number of insulin injections.

CONCLUSION

Metabolic control and hypoglycaemia are associated with intensity of treatment. Basal regimens have a reduced effect on metabolic control, but are associated with lower frequency of hypoglycaemia. Newer analogues, short- and long-acting, yield better control and less hypoglycaemia than older analogues.

The economic and clinical benefits of adequate insulin initiation and intensification in people with type 2 diabetes mellitus

AIM

To study the clinical and economic benefits associated with adequate and early initiation and intensification of insulin in people with type 2 diabetes mellitus (T2DM).

METHODS

A systematic review was performed using published articles from January 2000 to August 2010 that linked intervention, disease, study design and outcomes. Studies were further classified as initiation and intensification based on predefined criteria. Individual studies in systematic reviews and meta-analysis were searched and included if relevant.

RESULTS

A total of 2690 articles were screened with 76 (40 initiation and 36 intensification) studies included. Most initiation studies had mean baseline HbA1c values of >8.5%. The endpoint HbA1c values were reduced with insulin treatment in these studies, with endpoint values ranging from 6.6 to 9.8%. Similar results were seen with the intensification studies (endpoint HbA1c: 6.4-9.6%). Addition of insulin to oral antidiabetics (OADs) resulted in better glycaemic control in most studies. Blood glucose levels reduced substantially with OADs + insulin compared with OADs alone. Quality of life outcomes and treatment satisfaction were reported in six studies and not significantly different for insulin vs. OADs. Hypoglycaemic events were manageable with insulin initiation. However, all insulin types were associated with weight gain although the comparison with OADs elicited varying results.

CONCLUSIONS

Proactive management with early insulin initiation and intensification should be considered in people with T2DM in inadequate glycaemic control. The economic benefits with early initiation and intensification have to be fully explored.

Increase of body weight during the first year of intensive insulin treatment in type 2 diabetes: systematic review and meta-analysis

AIM

This systematic review and meta-analysis was to evaluate the body weight increase and its clinical correlates, through direct weighted regressions, as well as the effect of different insulin regimens and insulin analogues, through meta-analysis.

METHODS

Appropriate methodology according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was adhered to. Forty-six randomized studies, published as full papers, reporting the effect of insulin treatment on change in body weight were identified, and used to identify predictors of weight change; studies were included in a meta-analysis to study the effect of different insulin regimens or insulin analogues on weight change.

RESULTS

Intensity of treatment [aim of study (fasting blood glucose, mg/dl), dose of insulin, final HbA1c, change of HbA1c and frequency of hypoglycaemia] was significantly associated with body weight increase, with small differences between basal versus twice-a-day and prandial regimen. At meta-analysis, body weight increase was lower with basal regimen than with twice-a-day regimen and than with a prandial regimen. Within all regimens, body weight increase was lower with detemir than with NPH, with no difference between glargine and NPH; only two studies directly compared detemir and glargine, indicating lower weight gain with the former insulin. Within twice-a-day regimens and within prandial regimens, comparison was between newer analogues and older drugs, with no significant difference in body weight increase.

CONCLUSION

Body weight increase during the first year of insulin treatment is associated with the intensity of treatment; body weight increase also depends on the insulin regimen applied.

Predictors of responders to insulin therapy at 1 year among adults with type 2 diabetes

BACKGROUND

The effectiveness of insulin therapy to lower blood glucose levels in patients with type 2 diabetes (T2D) may depend on a variety of factors. This study aims to determine baseline parameters including body mass index (BMI) threshold that might predict responders to insulin therapy.

METHODS

This was a retrospective UK population-based study derived from 358 general practices electronic dataset. We included all patients with T2D, diagnosed at the age of >18 years old and who were initiated on insulin from January 2000 to December 2006. Insulin responders were defined as HbA1c <7.5% and/or HbA1c reduction by >1% at 12 months postinsulin initiation.

RESULTS

Results are expressed in mean (s.d.). A total of 6032 patients were identified. Baseline age was 63 years (11.7). In all, 61% of patients (3696) responded to insulin. At 1-year postinsulin initiation, HbA1c was significantly reduced (9.8 vs. 8.4%, p < 0.001) and weight increased (85.7 vs. 87.9 kg, p < 0.001). Using logistic regression model, older age (p < 0.001), lower BMI (p = 0.046), higher HbA1c (p < 0.001), basal-bolus insulin therapy and premixed insulin compared to basal insulin alone at baseline were independent predictors of responders to insulin. Gender and social class were not significant predictors of insulin responders. A BMI of <35.3 was derived as a cut-point for response to insulin (p = 0.038).

CONCLUSION

Overall, insulin therapy confers significant HbA1c reduction and weight increase in patients with T2D. The responsiveness to insulin therapy however appears to depend on baseline age, BMI, HbA1c and insulin regime. Clinicians should take these factors into consideration when making a decision to initiate insulin therapy in patients with T2D.

Optimal insulin regimens in type 2 diabetes mellitus: systematic review and meta-analyses

AIMS/HYPOTHESIS

We compared the effect of biphasic, basal or prandial insulin regimens on glucose control, clinical outcomes and adverse events in people with type 2 diabetes.

METHODS

We searched the Cochrane Library, MEDLINE, EMBASE and major American and European conference abstracts for randomised controlled trials up to October 2008. A systematic review and meta-analyses were performed.

RESULTS

Twenty-two trials that randomised 4,379 patients were included. Seven trials reported both starting insulin dose and titration schedules. Hypoglycaemia definitions and glucose targets varied. Meta-analyses were performed pooling data from insulin-naive patients. Greater HbA(1c) reductions were seen with biphasic and prandial insulin, compared with basal insulin, of 0.45% (95% CI 0.19-0.70, p = 0.0006) and 0.45% (95% CI 0.16-0.73, p = 0.002), respectively, but with lesser reductions of fasting glucose of 0.93 mmol/l (95% CI 0.21-1.65, p = 0.01) and 2.20 mmol/l (95% CI 1.70-2.70, p < 0.00001), respectively. Larger insulin doses at study end were reported in biphasic and prandial arms compared with basal arms. No studies found differences in major hypoglycaemic events, but minor hypoglycaemic events for prandial and biphasic insulin were inconsistently reported as either higher than or equivalent to basal insulin. Greater weight gain was seen with prandial compared with basal insulin (1.86 kg, 95% CI 0.80-2.92, p = 0.0006).

CONCLUSIONS/INTERPRETATION

Greater HbA(1c) reduction may be obtained in type 2 diabetes when insulin is initiated using biphasic or prandial insulin rather than a basal regimen, but with an unquantified risk of hypoglycaemia. Studies with longer follow-up are required to determine the clinical relevance of this finding.

Insulin therapy in type 2 diabetes: what is the evidence?

AIM

To systematically review the literature regarding insulin use in patients with type 2 diabetes mellitus

METHODS

A Medline and Embase search was performed to identify randomized controlled trials (RCT) published in English between 1 January 2000 and 1 April 2008, involving insulin therapy in adults with type 2 diabetes mellitus. The RCTs must comprise at least glycaemic control (glycosylated haemoglobin (HbA1c), postprandial plasma glucose and /or fasting blood glucose (FBG)) and hypoglycaemic events as outcome measurements.

RESULTS

The Pubmed search resulted in 943 hits; the Embase search gave 692 hits. A total of 116 RCTs were selected by title or abstract. Eventually 78 trials met the inclusion criteria. The studies were very diverse and of different quality. They comprised all possible insulin regimens with and without combination with oral medication. Continuing metformin and/or sulphonylurea after start of therapy with basal long-acting insulin results in better glycaemic control with less insulin requirements, less weight gain and less hypoglycaemic events. Long-acting insulin analogues in combination with oral medication are associated with similar glycaemic control but fewer hypoglycaemic episodes compared with NPH insulin. Most of the trials demonstrated better glycaemic control with premix insulin therapy than with a long-acting insulin once daily, but premix insulin causes more hypoglycaemic episodes. Analogue premix provides similar HbA1c, but lower postprandial glucose levels compared with human premix, without increase in hypoglycaemic events or weight gain. Drawing conclusions from the limited number of studies concerning basal-bolus regimen seems not possible. Some studies showed that rapid-acting insulin analogues frequently result in a better HbA1c or postprandial glucose without increase of hypoglycaemia than regular human insulin.

CONCLUSION

A once-daily basal insulin regimen added to oral medication is an ideal starting point. All next steps, from one to two or even more injections per day should be taken very carefully and in thorough deliberation with the patient, who has to comply with such a regimen for many years.