Insulin glargine improves glycaemic control after coronary surgery in patients with diabetes or pre-diabetes

Sliding scale insulin for non-critically ill hospitalised adults with diabetes mellitus

BACKGROUND

Diabetes mellitus is a metabolic disorder resulting from a defect in insulin secretion, function, or both. Hyperglycaemia in non-critically ill hospitalised people is associated with poor clinical outcomes (infections, prolonged hospital stay, poor wound healing, higher morbidity and mortality). In the hospital setting people diagnosed with diabetes receive insulin therapy as part of their treatment in order to achieve metabolic control. However, insulin therapy can be provided by different strategies (sliding scale insulin (SSI), basal-bolus insulin, and other modalities). Sliding scale insulin is currently the most commonly used method, however there is uncertainty about which strategy provides the best patient outcomes.

OBJECTIVES

To assess the effects of SSI for non-critically ill hospitalised adults with diabetes mellitus.

SEARCH METHODS

We identified eligible trials by searching MEDLINE, Embase, LILACS, and the Cochrane Library. We searched the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) and ClinicalTrials.gov trial registers. The date of the last search for all databases was December 2017. We also examined reference lists of identified randomised controlled trials (RCTs) and systematic reviews, and contacted trial authors.

SELECTION CRITERIA

We included RCTs comparing SSI with other strategies for glycaemic control in non-critically ill hospitalised adult participants of any sex with diabetes mellitus.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data, assessed trials for risk of bias, and evaluated the overall certainty of evidence utilising the GRADE instrument. We synthesised data using a random-effects model meta-analysis with 95% prediction intervals, if possible, or descriptive analysis, as appropriate.

MAIN RESULTS

Of 720 records screened, we included eight trials that randomised 1048 participants with type 2 diabetes (387 SSI participants and 615 participants in comparator groups were available for final analysis). We included non-critically ill medical and surgical adults with the diagnosis of diabetes mellitus. The mean follow-up time was measured by the mean length of hospital stay and ranged between five and 24 days. The mean age of participants was 44.5 years to 71 years.Overall, we judged the risk of bias on the trial level as unclear for selection bias, high for outcome-related performance and detection bias with regard to hypoglycaemic episodes, other adverse events, and mean glucose levels, and low for all-cause mortality and length of hospital stay. Attrition bias was low for all outcome measures.Six trials compared SSI with a basal-bolus insulin scheme, three of which investigating 64% of all participants in this category also applying an SSI approach in the bolus comparator part. One trial had a basal insulin-only comparator arm, and the remaining trial used continuous insulin infusion as the comparator. For our main comparison of SSI versus basal-bolus insulin, the results were as follows. Four trials reported mortality data. One out of 268 participants in the SSI group (0.3%) compared with two out of 334 participants in the basal-bolus group (0.6%) died (low-certainty evidence). Severe hypoglycaemic episodes, defined as blood glucose levels below 40 mg/dL (2.2 mmol/L), showed a risk ratio (RR) of 0.22, 95% confidence interval (CI) 0.05 to 1.00; P = 0.05; 5 trials; 667 participants; very low-certainty evidence. The 95% prediction interval ranged between 0.02 and 2.57. All nine severe hypoglycaemic episodes were observed among the 369 participants on basal-bolus insulin (2.4%). The mean length of hospital stay was 0.5 days longer for the SSI group, 95% CI -0.5 to 1.4; P = 0.32; 6 trials; 717 participants; very low-certainty evidence. The 95% prediction interval ranged between -1.7 days and 2.7 days. Adverse events other than hypoglycaemic episodes, such as postoperative infections, showed a RR of 1.16, 95% CI 0.25 to 5.37; P = 0.85; 3 trials; 481 participants; very low-certainty evidence. The mean blood glucose levels ranged across basal-bolus groups from 156 mg/dL (8.7 mmol/L) to 221 mg/dL (12.3 mmol/L). The mean blood glucose level in the SSI groups was 14.8 mg/dL (0.8 mmol/L) higher (95% CI 7.8 (0.4) to 21.8 (1.2); P < 0.001; 6 trials; 717 participants; low-certainty evidence). The 95% prediction interval ranged between -3.6 mg/dL (-0.2 mmol/L) and 33.2 mg/dL (1.8 mmol/L). No trial reported on diabetes-related mortality or socioeconomic effects.

AUTHORS' CONCLUSIONS

We are uncertain which insulin strategy (SSI or basal-bolus insulin) is best for non-critically hospitalised adults with diabetes mellitus. A basal-bolus insulin strategy in these patients might result in better short-term glycaemic control but could increase the risk for severe hypoglycaemic episodes. The certainty of the body of evidence comparing SSI with basal-bolus insulin was low to very low and needs to be improved by adequately performed, well-powered RCTs in different hospital environments with well-educated medical staff using identical short-acting insulins in both intervention and comparator arms to compare the rigid SSI approach with flexible insulin application strategies.

Comparative efficacy and safety of insulin analogs in hospitalized adults

PURPOSE

The comparative efficacy, safety, and cost-effectiveness of rapid and long-acting insulin analogs compared with regular or neutral protamine Hagedorn nonanalog insulins or with oral antidiabetic agents in hospitalized adults were evaluated.

METHODS

A literature search was conducted to identify studies that compared the effects of rapid-acting, long-acting, or mixed insulin analogs with short- or intermediate-acting insulin or any other oral antidiabetic medication.

RESULTS

Twenty-three primary studies were included in the review. Rapid-acting analogs and basal-bolus analog regimens were found to reduce the duration of hospital stay by approximately one day compared with regular insulin and basal-bolus nonanalog regimens. One large cohort study found an adjusted 48% relative risk reduction in mortality with rapid-acting analogs versus regular insulin in a heterogeneous hospitalized hyperglycemic population. A randomized controlled trial found a significant reduction in postoperative complications with basal-bolus analogs compared with basal-bolus nonanalog insulin. When compared with regular sliding-scale insulin (SSI), fixed-dose insulin glargine with or without insulin glulisine was found to reduce the blood glucose concentration in patients with type 2 diabetes and reduce postoperative complications in surgical patients with diabetes. The quality of evidence was primarily very low or low for most outcomes.

CONCLUSION

A systematic literature review revealed a very low or low quality of evidence, suggesting that, compared with nonanalog regimens, rapid-acting insulin analogs reduce the duration of hospital stay and mortality rates and that basal- bolus analog regimens may reduce the duration of hospital stay and postoperative complications. There is also a low quality of evidence to suggest that a fixed-dose analog regimen of insulin glargine with or without insulin glulisine is more effective than regular SSI for reducing blood glucose concentrations and postoperative complications.

Sliding-scale insulin used for blood glucose control: a meta-analysis of randomized controlled trials

BACKGROUND

Sliding-scale insulin has been widely used in treating inpatient hyperglycemia. A systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted to evaluate the efficacy and possible adverse effects of sliding-scale insulin in hospitalized patients.

METHODS

PubMed, EMBASE, Cochrane Library, Scopus, and ClinicalTrials.gov registry were searched for studies published up to May 2015. Individual effect sizes were standardized, and a meta-analysis was performed to calculate a pooled effect size using random effects models.

RESULTS

Eleven RCTs containing a total of 1322 patients were identified. Among eight studies in which the RISS was compared with other regimens, no significant difference was observed in the percentage of patients who achieved the mean blood glucose level between the two groups, which was determined according to the numbers of blood samples (RR: 2.84; 95% CI: 0.94 to 8.59) and patients (RR: 1.75; 95% CI: 0.86 to 3.55). The mean blood glucose level (weighted mean difference=27.33, 95% CI: 14.74 to 39.92) and incidence of hyperglycemic events were significantly higher in the RISS group than in the non-sliding-scale group. No significant difference in the incidence of severe hypoglycemia and length of hospitalization between the groups was identified.

CONCLUSIONS

The overall results of the meta-analysis indicated that applying the RISS alone or in combination with other antidiabetic medications did not provide any benefits in blood glucose control, but was accompanied by an increased incidence of hyperglycemic events. Therefore, we suggest that the use of sliding-scale insulin be discontinued in hospitals.

Perioperative glycaemic control for diabetic patients undergoing surgery

BACKGROUND

Patients with diabetes mellitus are at increased risk of postoperative complications. Data from randomised clinical trials and meta-analyses point to a potential benefit of intensive glycaemic control, targeting near-normal blood glucose, in patients with hyperglycaemia (with and without diabetes mellitus) being submitted to surgical procedures. However, there is limited evidence concerning this question in patients with diabetes mellitus undergoing surgery.

OBJECTIVES

To assess the effects of perioperative glycaemic control for diabetic patients undergoing surgery.

SEARCH METHODS

Trials were obtained from searches of The Cochrane Library, MEDLINE, EMBASE, LILACS, CINAHL and ISIS (all up to February 2012).

SELECTION CRITERIA

We included randomised controlled clinical trials that prespecified different targets of perioperative glycaemic control (intensive versus conventional or standard care)

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and assessed risk of bias. We summarised studies using meta-analysis or descriptive methods.

MAIN RESULTS

Twelve trials randomised 694 diabetic participants to intensive control and 709 diabetic participants to conventional glycaemic control. The duration of the intervention ranged from just the duration of the surgical procedure up to 90 days. The number of participants ranged from 13 to 421, and the mean age was 64 years. Comparison of intensive with conventional glycaemic control demonstrated the following results for our predefined primary outcomes: analysis restricted to studies with low or unclear detection or attrition bias for infectious complications showed a risk ratio (RR) of 0.46 (95% confidence interval (CI) 0.18 to 1.18), P = 0.11, 627 participants, eight trials, moderate quality of the evidence (grading of recommendations assessment, development and evaluation - (GRADE)). Evaluation of death from any cause revealed a RR of 1.19 (95% CI 0.89 to 1.59), P = 0.24, 1365 participants, 11 trials, high quality of the evidence (GRADE).On the basis of a posthoc analysis, there is the hypothesis that intensive glycaemic control may increase the risk of hypoglycaemic episodes if longer-term outcome measures are analysed (RR 6.92, 95% CI 2.04 to 23.41), P = 0.002, 724 patients, three trials, low quality of the evidence (GRADE). Analysis of our predefined secondary outcomes revealed the following findings: cardiovascular events had a RR of 1.03 (95% CI 0.21 to 5.13), P = 0.97, 682 participants, six trials, moderate quality of the evidence (GRADE) when comparing the two treatment modalities; and renal failure also did not show significant differences between intensive and regular glucose control (RR 0.61, 95% CI 0.34 to 1.08), P = 0.09, 434 participants, two trials, moderate quality of the evidence (GRADE). We did not meta-analyse length of hospital stay and intensive care unit (ICU) stay due to substantial unexplained heterogeneity. Mean differences between intensive and regular glucose control groups ranged from -1.7 days to 2.1 days for ICU stay and between -8 days to 3.7 days for hospital stay (moderate quality of the evidence (GRADE)). One trial assessed health-related quality of life in 12/37 (32.4%) of participants in the intervention group and 13/44 (29.5%) of participants in the control group, and did not show an important difference (low quality of the evidence (GRADE)) in the measured physical health composite score of the short-form 12-item health survey (SF-12). None of the trials examined the effects of the interventions in terms of costs.

AUTHORS' CONCLUSIONS

The included trials did not demonstrate significant differences for most of the outcomes when targeting intensive perioperative glycaemic control compared with conventional glycaemic control in patients with diabetes mellitus. However, posthoc analysis indicated that intensive glycaemic control was associated with an increased number of patients experiencing hypoglycaemic episodes. Intensive glycaemic control protocols with near-normal blood glucose targets for patients with diabetes mellitus undergoing surgical procedures are currently not supported by an adequate scientific basis. We suggest that insulin treatment regimens, patient- and health-system relevant outcomes, and time points for outcome measures should be defined in a thorough and uniform way in future studies.