Trends in recorded capillary blood glucose and hypoglycaemia in hospitalised patients with diabetes

Spontaneous and iatrogenic hypoglycemia in cystic fibrosis

Spontaneous episodes of hypoglycemia can occur in people with cystic fibrosis (CF) without diabetes, who are not on glucose lowering medications. Spontaneous hypoglycemia in CF could occur both in the fasting or postprandial state (reactive hypoglycemia). The pathophysiology of fasting hypoglycemia is thought to be related to malnutrition and increased energy expenditure in the setting of inflammation and acute infections. Reactive hypoglycemia is thought to be due to impaired first phase insulin release in response to a glucose load, followed by a delayed and extended second phase insulin secretion; ineffective counterregulatory response to dropping glucose levels may also play a role. The overall prevalence of spontaneous hypoglycemia varies from 7 to 69% as examined with oral glucose tolerance test (OGTT) or with continuous glucose monitoring (CGM) under free living conditions. Spontaneous hypoglycemia in CF is associated with worse lung function, higher hospitalization rates, and worse clinical status. In addition, patients with CF related diabetes on glucose-lowering therapies are at risk for iatrogenic hypoglycemia. In this article, we will review the pathophysiology, prevalence, risk factors, clinical implications, and management of spontaneous and iatrogenic hypoglycemia in patients with CF.

Admission Glucose Number (AGN): A Point of Admission Score Associated With Inpatient Glucose Variability, Hypoglycemia, and Mortality

AIMS

We investigated a point of admission metric of glycemia, the Admission Glucose Number (AGN), and its relationship with both high risk inpatient glucose patterns and mortality in hospital inpatients with type 2 diabetes (T2DM).

METHODS

Inpatient capillary blood glucose (CBG) data for patients with T2DM in our health board were identified for a 5-year period and associated with most recent preadmission HbA1c. AGN was calculated as first CBG measured during admission (mmol/L), subtracted from most recent preadmission HbA1c (converted to estimated median glucose mmol/l) within 15 months preadmission. The association between AGN and CBG variability (interquartile range), hypoglycemia free survival (HR) and both inpatient and 100-day mortality (HR) were investigated.

RESULTS

A total of 21 045 first admissions with available HbA1c data were identified. A positive correlation between AGN and glycemic variability was described (partial correlation coefficient 0.25, P < .001), which was stronger than the correlation of either of AGNs' individual components: adjusted CBG1 = 0.07 ( P < .001), eAG = 0.08 ( P < .001). The hazard ratio for time to first recorded CBG < 3 mmol/L for high AGN versus low AGN was 1.74 (95% CI 1.55-1.96), P < .001. A high AGN was associated with increased 100-day mortality (HR 1.26, P = .005), however not with in-hospital mortality (HR = 1.31, P = .08).

CONCLUSION

AGN is a simple metric that combines 2 readily available measures associated with adverse outcome in T2DM. AGN may be a useful tool to stratify patients for risk of hypoglycemia and postdischarge death.

A Systematic Approach for the Prevention and Reduction of Hypoglycemia in Hospitalized Patients

PURPOSE OF REVIEW

Hypoglycemia and severe hypoglycemia (SH) in the inpatient setting are associated with poor outcomes. This review is designed to highlight approaches to predict and prevent inpatient hypoglycemia that has been successfully implemented focusing on developing overlapping policies and procedures that allow safe glycemic management to occur at all levels of the institution.

RECENT FINDINGS

Standardizing point-of-care (POC) testing, nursing protocols, meal delivery, and formulary restriction are useful tools to prevent hypoglycemia. Informatics and real-time alert processes are highly effective tools to reduce hypoglycemia but require a significant investment in time and infrastructure as well as clear policies on how alerts are acted upon. Computerized dosing support technology and continuous glucose monitoring (CGM) technology are an emerging area of investigation showing promising results. Inpatient hypoglycemia is often predictable and preventable and requires institutional support to deliver targeted and safe diabetes care. This requires each institution to do periodic reassessment of policies and technologies. Future research needs to focus on the cost/benefits of interventions including studies of automated dosing algorithms as well as CGM in higher-risk patient populations.

Hypoglycemia and Clinical Outcomes in Hospitalized Patients With Diabetes: Does Association With Adverse Outcomes Remain When Number of Glucose Tests Performed Is Accounted For?

BACKGROUND

Hypoglycemia is associated with increased length of stay in hospital patients, but previous studies have not considered the confounding effect of increased hypoglycemia detection associated with increased capillary blood glucose (CBG) measurement in prolonged admissions. We aimed to determine the effect of recorded hypoglycemia on length of stay of hospital inpatients (LOS) when this mathematical association is subtracted.

METHODS

CBG data were analyzed for inpatients within our health board area (01/2009-01/2015). A simulated CBG data set was generated for each patient with an identical sampling frequency to the measured CBG data set. The mathematical component of increased LOS was determined using the simulated data set. Subtraction of this confounding mathematical association was used to provide measurement of the true clinical association between recorded hypoglycemia (CBG < 4 mmol [< 72mg/dl]) and LOS.

RESULTS

A total of 196 962 admissions of 52 475 individuals with known diabetes were analyzed. 68 809 admissions of 29 551 individuals had >4 CBG measurements made and were included in analysis. After subtraction of the mathematical association of increased sample number, the clinical effect of recorded hypoglycemia is reduced-but persists-compared to previous studies. 1-2 days with recorded hypoglycemia has a relatively minor effect on LOS. LOS increases rapidly if there are ≥3 days with recorded hypoglycemia, with an increase of 0.75 days LOS per additional day with hypoglycemia.

CONCLUSIONS

This technique increases accuracy of economic modeling of the impact of hypoglycemia on health care systems. This could assist study of the impact of hypoglycemia on other outcomes by factoring for bias of increased sample numbers.

Is all hypoglycaemia treated as equal? An observational study of how the type of diabetes and treatment prescribed prior to admission influences quality of treatment of inpatient hypoglycaemia

AIMS

Inpatient hypoglycaemia is common and associated with adverse outcomes. There is often increased vigilance of hypoglycaemia in inpatients with type 1 diabetes (T1DM) compared to type 2 diabetes (T2DM). We aimed to investigate this apparent discrepancy, utilising the time to repeat (TTR) capillary blood glucose (CBG) measurement as a surrogate for engagement with guidelines stating that CBG should be rechecked following intervention within 15 min of an initial CBG of <4 mmol/L.

METHODS

This is an observational study of inpatient CBG data from 8 hospitals over a 7-year period. A national diabetes registry allowed identification of individual's diagnosis and diabetes therapy. For each initial (index) CBG, the TTR for individuals with T2DM-on insulin or sulphonylurea-was compared with the TTR for individuals with T1DM, using a t test for significance performed on log(TTR). The median TTR was plotted for each group per index CBG.

RESULTS

In total, 1480,335 CBG measurements were obtained. A total of 26,664 were <4 mmol/L. The TTR in T2DM individuals on sulphonylurea was significantly greater than in T1DM individuals where index CBG was ≥2.3 mmol/L (except index CBG 2.6 mmol/L). For T2DM patients receiving insulin significance exists for index CBGs of ≥3.2 mmol/L.

CONCLUSIONS

This analysis suggests that quality of care of hypoglycaemia varies according to diagnosis and medication. The group with the highest TTR (T2DM sulphonylurea treated) are possibly the clinical group in whom hypoglycaemia is most concerning. These data therefore suggest a need for education and raising awareness within the inpatient nursing staff.

A Practical Approach to Glucose Abnormalities in Cystic Fibrosis

Cystic fibrosis is a common genetic condition and abnormal glucose handling leading to cystic fibrosis-related diabetes (CFRD) is a frequent comorbidity. CFRD is mainly thought to be the result of progressive pancreatic damage resulting in beta cell dysfunction and loss of insulin secretion. Whilst Oral Glucose Tolerance Testing is still recommended for diagnosing CFRD, the relationship between glucose abnormalities and adverse outcomes in CF is complex and occurs at stages of dysglycaemia occurring prior to diagnosis of diabetes by World Health Organisation criteria. Insulin remains the mainstay of treatment of CF-related glucose abnormalities but the timing of insulin commencement, optimum insulin regime and targets of glycaemic control are not clear. These complexities are compounded by common issues with nutritional status, need for enteral feeding, steroid use and high disease burden on CF patients.

Patterns and Impact of Hypoglycemia, Hyperglycemia, and Glucose Variability on Inpatients with Insulin-Treated Cystic Fibrosis-Related Diabetes

INTRODUCTION

Mortality in patients with cystic fibrosis-related diabetes (CFRD) is higher than that in patients with cystic fibrosis without diabetes. Hypoglycemia, hyperglycemia, and glucose variability confer excess mortality and morbidity in the general inpatient population with diabetes.

METHODS

We investigated patterns of hypoglycemia and the association of hypoglycemia, hyperglycemia, and glucose variability with mortality and readmission rate in inpatients with CFRD. All capillary blood glucose (CBG) readings (measured using the Abbott Precision web system) of patients with insulin-treated CFRD measured within our health board between January 2009 and January 2015 were. Frequency and timing of hypoglycemia (<4 mmol/L) and was recorded. The effect of dysglycemia on readmission and mortality was investigated with survival analysis.

RESULTS

Sixty-six patients were included. A total of 22,711 CBG results were included in the initial analysis. Hypoglycemia was common with 1433 episodes (6.3%). Hypoglycemia ascertainment was highest between 2400 and 0600 h. Hypoglycemia was associated with a significantly higher rate of readmission or death over the 3.5-year follow-up period (P = 0.03). There was no significant association between hyperglycemia or glucose variability and the rate of readmission and mortality.

CONCLUSION

Among inpatients with CFRD hypoglycemia is common and is associated with an increased composite endpoint of readmission and death. As with previously reported trends in general inpatient population this group shows a peak incidence of hypoglycemic during the night.

Predictors of recurrent hypoglycemia following a severe hypoglycemic event among hospitalized patients

OBJECTIVES

Severe hypoglycemia is associated with poor hospital outcomes, but variables contributing to the adequacy of treatment have not been described. The objective of this study was to determine predictors of recurrent hypoglycemia among hospitalized patients with a severe hypoglycemic event.

METHODS

Patients with severe hypoglycemia (glucose <40 mg/dl) with a concomitant insulin order were identified using the study institution's Information Warehouse. The primary outcome was the prevalence of recurrent hypoglycemia (defined as <70 mg/dl within 24 hours) and to identify independent predictors of recurrent hypoglycemia. Secondary outcomes included time to blood glucose recheck, time to blood glucose ≥ 70 mg/dl, and rebound hyperglycemia (defined as glucose >300 mg/dl within 24 hours). Multivariable linear and logistic regression models were performed.

RESULTS

A total of 129 patients with severe hypoglycemia were identified. The median time to repeat glucose measurement was 29 (IQR 15-61) minutes, while the time to resolution of hypoglycemia was 49 (IQR 26-103) minutes. Recurrent hypoglycemia occurred in 49% of patients, while 19% of patients experienced rebound hyperglycemia. Independent predictors of recurrent hypoglycemia included lower repeat glucose (p = 0.025), low glomerular filtration rate (p = 0.033), and lack of insulin adjustment (p = 0.012). Independent predictors of maximum glucose post-event were type 1 diabetes (p = 0.0003), history of any diabetes (p = 0.013), and total bolus dose of insulin (p < 0.0001). Overnight timing of events was the only predictor of shorter time to hypoglycemia resolution (p < 0.0001).

CONCLUSIONS

Recurrent hypoglycemia following severe hypoglycemia is common in the hospital, suggesting the need for enhanced monitoring in such patients. Further research is needed to identify methods to reduce the incidence of recurrent hypoglycemia.

Taking a Closer Look--Continuous Glucose Monitoring in Non-Critically Ill Hospitalized Patients with Type 2 Diabetes Mellitus Under Basal-Bolus Insulin Therapy

BACKGROUND

Inpatient glucose management is based on four daily capillary blood glucose (BG) measurements. The aim was to test the capability of continuous glucose monitoring (CGM) for assessing the clinical impact and safety of basal-bolus insulin therapy in non-critically ill hospitalized patients with type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

Eighty-four patients with T2DM (age, 68±10 years; glycosylated hemoglobin, 72±28 mmol/mol; body mass index, 31±7 kg/m(2)) were treated with basal-bolus insulin. CGM was performed with the iPro(®)2 system (Medtronic MiniMed, Northridge, CA) and calibrated retrospectively.

RESULTS

A remarkable consistency between CGM and BG measurements and therapy improvement was shown over the study period of 501 patient-days. The number of CGM and BG measurements (CGM/BG) in the range from 3.9-10 mmol/L increased from 67.7%/67.2% (on Day 1) to 77.5%/78.6% (on the last day) (P<0.04). The number of low glycemic episodes (3.3 to <3.9 mmol/L) during nighttime detected by CGM was 15-fold higher, and the number of episodes >13.9 mmol/L detected by CGM during night was 12.5-fold higher than the values from the BG measurements. Ninety-nine percent of data points were in the clinically accurate or acceptable Clarke Error Grid Zones A+B, and the relative numbers of correctly identified episodes of <3.9 and >13.9 mmol/L detected by CGM (sensitivity) were 47.3% and 81.5%, respectively.

CONCLUSIONS

Our data exhibit a good agreement between overall CGM and BG measurements, but there were a high number of missed hypo- and hyperglycemic episodes with BG measurements, particularly during nighttime. Overall assessment of glycemic control using CGM is feasible, whereas the use of CGM for individualized therapy decisions needs further improvement.

Randomized controlled trial of insulin supplementation for correction of bedtime hyperglycemia in hospitalized patients with type 2 diabetes

OBJECTIVE

Clinical guidelines recommend point-of-care glucose testing and the use of supplemental doses of rapid-acting insulin before meals and at bedtime for correction of hyperglycemia. The efficacy and safety of this recommendation, however, have not been tested in the hospital setting.

RESEARCH DESIGN AND METHODS

In this open-label, randomized controlled trial, 206 general medicine and surgery patients with type 2 diabetes treated with a basal-bolus regimen were randomized to receive either supplemental insulin (n = 106) at bedtime for blood glucose (BG) >7.8 mmol/L or no supplemental insulin (n = 100) except for BG >19.4 mmol/L. Point-of-care testing was performed before meals, at bedtime, and at 3:00 a.m. The primary outcome was the difference in fasting BG. In addition to the intention-to-treat analysis, an as-treated analysis was performed where the primary outcome was analyzed for only the bedtime BG levels between 7.8 and 19.4 mmol/L.

RESULTS

There were no differences in mean fasting BG for the intention-to-treat (8.8 ± 2.4 vs. 8.6 ± 2.2 mmol/L, P = 0.76) and as-treated (8.9 ± 2.4 vs. 8.8 ± 2.4 mmol/L, P = 0.92) analyses. Only 66% of patients in the supplement and 8% in the no supplement groups received bedtime supplemental insulin. Hypoglycemia (BG <3.9 mmol/L) did not differ between groups for either the intention-to-treat (30% vs. 26%, P = 0.50) or the as-treated (4% vs. 8%, P = 0.37) analysis.

CONCLUSIONS

The use of insulin supplements for correction of bedtime hyperglycemia was not associated with an improvement in glycemic control. We conclude that routine use of bedtime insulin supplementation is not indicated for management of inpatients with type 2 diabetes.