Continuation versus discontinuation of insulin secretagogues when initiating insulin in type 2 diabetes.

We compared the combined use of basal insulin, metformin and insulin secretagogues with a combination of basal insulin and metformin in patients with type 2 diabetes starting basal insulin analogue therapy. This analysis was part of a 24-week trial, in which 964 insulin-naive patients with type 2 diabetes inadequately controlled on oral agents (including metformin) were randomized to insulin glargine or detemir. Secretagogues were stopped or maintained at the site-investigators' discretion. During the study, 57.6% of patients continued their secretagogue treatment. Compared with patients stopping secretagogues, those who continued experienced significantly more hypoglycaemia and weight gain. Insulin doses, however, were significantly lower: 0.6 ± 0.4 versus 0.8 ± 0.4 U/kg/day (p < 0.001). The difference between groups in mean HbA1c reduction was not statistically significant. In conclusion, in type 2 diabetic patients starting basal insulin analogue therapy, continuing both metformin and secretagogues results in more hypoglycaemia and weight gain and lower insulin doses than only maintaining metformin.

Contact frequency determines outcome of basal insulin initiation trials in type 2 diabetes.

AIMS/HYPOTHESIS: The aim of the present study was to investigate whether predetermined contact frequency with the study team and endpoint insulin dose are associated with study outcomes in basal insulin initiation trials in type 2 diabetes. METHODS: A systematic Medline search was performed. Using data from the selected studies, contact frequency was plotted against HbA(1c) reduction and endpoint insulin dose. The importance of face-to-face vs telephone contact was also analysed. Insulin dose was plotted against HbA(1c) reduction, hypoglycaemia rate and weight gain. To investigate non-specific study effects, the relationship between contact frequency and HbA(1c) was also assessed in dipeptidyl peptidase-4 (DPP-4) inhibitor trials. RESULTS: The reduction in HbA(1c) was highly correlated with contact frequency and endpoint insulin dose (r (2) = 0.751, p < 0.001 and r (2) = 0.433, p = 0.008, respectively). However, after adjusting for contact frequency, the relationship between insulin dose and HbA(1c) reduction was no longer significant (p = 0.270). The frequency of both clinical and telephone contacts were independent predictors of HbA(1c) improvement (p = 0.010 and p < 0.001, respectively). We found no dose-response relationship between end-of-study insulin dose and hypoglycaemia or weight gain. In DPP-4 inhibitor studies, contact frequency was not positively associated with HbA(1c). CONCLUSIONS/INTERPRETATION: The frequency of contact with the study team is highly correlated with the improvement in HbA(1c) achieved in basal insulin initiation trials in type 2 diabetic patients. This has important implications for trial design and interpretation, as well as for clinical care.

Changing the glucose cut-off values that define hypoglycaemia has a major effect on reported frequencies of hypoglycaemia.

AIMS/HYPOTHESIS: The aim of this analysis was to quantify the relationship between the frequency of hypoglycaemia and various glucose cut-off points for the definition of hypoglycaemia, within a range of HbA(1c) strata. METHODS: Data from two trials examining insulin glargine dose titration in 12,837 type 2 diabetic participants starting insulin therapy were combined. Curves for hypoglycaemia frequency plotted against endpoint HbA(1c) level were constructed, using a range of glucose cut-off points for hypoglycaemia. RESULTS: During the 12-week study period, 3,912 patients recorded 21,592 hypoglycaemic episodes, comprising 242 severe, 8,871 symptomatic and 12,479 asymptomatic events, corresponding to hypoglycaemia event rates of 0.10, 3.8 and 5.3 events per patient year. Increasing the hypoglycaemia cut-off point from, for instance, <3.1 to <3.9 mmol/l more than doubled the percentage of affected patients, e.g. from 17.7 to 43.3% at HbA(1c) 7.0-7.2%. At higher hypoglycaemia cut-off points the proportion of patients having only asymptomatic hypoglycaemia increased, e.g. from 30.7% at <3.1 mmol/l to 61.7% of patients at a cut-off point of <3.9 mmol/l. In sensitivity analysis, 121 of 1,756 patients with at least one self-monitored blood glucose value <3.1 mmol/l experienced severe hypoglycaemia, compared with 149 of 3,912 patients with a self-monitored blood glucose level of <3.9 mmol/l. Thus, to identify 28 more patients with severe hypoglycaemia, the number of patients experiencing only non-severe hypoglycaemia more than doubled. CONCLUSIONS/INTERPRETATION: The glucose cut-off point defining hypoglycaemia greatly affects the reported frequency of hypoglycaemia. When hypoglycaemia is to be defined by a predetermined glucose level, to have clinical relevance the cut-off should be set at a lower level than the threshold of 3.9 mmol/l proposed by the American Diabetes Association.

The interpretation of glucose clamp studies of long-acting insulin analogues: from physiology to marketing and back.

Glucose clamp studies assessing the time-action profile of long-acting insulin analogues have reported conflicting results. In an attempt to reconcile the data, we organised an expert meeting of four leading European clamp groups, during which consensus was reached on some but not all points discussed. In this paper, which reflects our personal views only, we aim to provide guidance for readers and reviewers on the interpretation of this type of clamp study and to clarify its inherent limitations.Glucose clamp studies are either performed manually or using an automated procedure, but differences in clamp methodology hardly seem a satisfactory explanation for the conflicting results. (Un)conscious investigator-related bias, especially during manual studies, cannot be ruled out, despite attempts at blinding the study insulin during the clamp.The duration of action of study insulins is influenced by many factors, such as glucose and insulin levels prior to injection, endogenous insulin secretion, insulin dose, definitions used for onset and end of action, and insulin sensitivity (which is influenced by the necessity of fasting during the clamp). These factors limit the translation of clamp study results into daily practice.Because of the inherent limitations of the glucose clamp technique and the lack of reproducibility of the outcomes, its results should be regarded as no more than an indication of the clinical action profile of long-acting insulin preparations.