Continuous glucose monitoring as a tool to identify hyperglycaemia in non-diabetic patients with acute coronary syndromes

Evaluation of continuous glucose monitoring system for detection of alterations in glucose homeostasis in pediatric patients with β-thalassemia major

BACKGROUND

Disturbances of glucose metabolism are common in β-thalassemia major (β-TM).

AIM

This study was conducted to assess the pattern of glucose homeostasis in pediatric β-TM patients comparing oral glucose tolerance test (OGTT) and continuous glucose monitoring system (CGMS).

METHODS

Two-hundred β-TM patients were studied and those with random blood glucose (RBG) ≥7.8 mmol/L (140 mg/dL) were subjected to OGTT, insertion of CGMS and measurement of fasting C peptide, fasting insulin, and hemoglobin A1c (HbA1c).

RESULTS

Twenty patients (10%) had RBG ≥ 7.8 mmol/L. Using OGTT, 6 out of 20 patients (30%) had impaired glucose tolerance (IGT) while 7 (35%) patients were in the diabetic range. CGMS showed that 7/20 (35%) patients had IGT and 13 (65%) patients had diabetes mellitus (DM); 10 of the latter group had HbA1c readings within diabetic range. The percentage of diabetic patients diagnosed by CGMS was significantly higher than that with OGTT (P = 0.012). Serum ferritin was the only independent variable related to elevated RBG. All β-TM patients with DM were non-compliant to chelation therapy.

CONCLUSIONS

The use of CGMS in the diagnosis of early glycemic abnormalities among pediatric patients with β-TM appears to be superior to other known diagnostic modalities.

Continuous glucose monitoring system and new era of early diagnosis of diabetes in high risk groups

Continuous glucose monitoring (CGM) systems are an emerging technology that allows frequent glucose measurements to monitor glucose trends in real time. Their use as a diagnostic tool is still developing and appears to be promising. Combining intermittent glucose self-monitoring (SGM) and CGM combines the benefits of both. Significant improvement in the treatment modalities that may prevent the progress of prediabetes to diabetes have been achieved recently and dictates screening of high risk patients for early diagnosis and management of glycemic abnormalities. The use of CGMS in the diagnosis of early dysglycemia (prediabetes) especially in high risk patients appears to be an attractive approach. In this review we searched the literature to investigate the value of using CGMS as a diagnostic tool compared to other known tools, namely oral glucose tolerance test (OGTT) and measurement of glycated hemoglobin (HbA1C) in high risk groups. Those categories of patients include adolescents and adults with obesity especially those with family history of type 2 diabetes mellitus, polycystic ovary syndrome (PCO), gestational diabetes, cystic fibrosis, thalassemia major, acute coronary syndrome (ACS), and after renal transplantation. It appears that the ability of the CGMS for frequently monitoring (every 5 min) glucose changes during real-life settings for 3 to 5 days stretches the chance to detect more glycemic abnormalities during basal and postprandial conditions compared to other short-timed methods.

Continuous glucose monitoring in acute coronary syndrome

BACKGROUND

Diabetes mellitus is an independent risk factor for cardiovascular disease.

OBJECTIVE

To compare the efficacy of devices for continuous glucose monitoring and capillary glucose monitoring in hospitalized patients with acute coronary syndrome using the following parameters: time to achieve normoglycemia, period of time in normoglycemia, and episodes of hypoglycemia.

METHODS

We performed a pilot, non-randomized, unblinded clinical trial that included 16 patients with acute coronary artery syndrome, a capillary or venous blood glucose ≥ 140 mg/dl, and treatment with a continuous infusion of fast acting human insulin. These patients were randomized into 2 groups: a conventional group, in which capillary measurement and recording as well as insulin adjustment were made every 4h, and an intervention group, in which measurement and recording as well as insulin adjustment were made every hour with a subcutaneous continuous monitoring system. Student's t-test was applied for mean differences and the X(2) test for qualitative variables.

RESULTS

We observed a statistically significant difference in the mean time for achieving normoglycemia, favoring the conventional group with a P = 0.02.

CONCLUSION

Continuous monitoring systems are as useful as capillary monitoring for achieving normoglycemia.

Continuous glucose monitoring after kidney transplantation in non-diabetic patients: early hyperglycaemia is frequent and may herald post-transplantation diabetes mellitus and graft failure

OBJECTIVES

New onset of diabetes after transplantation (NODAT) is a known complication of renal transplantation, but early glycaemic status after transplantation has not been described prospectively. This study aimed to assess blood glucose (BG) levels immediately following kidney transplantation in non-diabetic subjects and to explore their relationship to later graft outcomes and NODAT occurrence.

PATIENTS AND METHODS

Over a 9-month period, 43 consecutive non-diabetic patients who received a kidney transplant were prospectively investigated. During the first 4 days after transplantation, fasting BG was measured and the 24-h BG profile assessed by continuous glucose monitoring (CGM). Capillary BG was measured on hospital admittance and at least four times a day for CGM calibration thereafter. All adverse events were recorded, and fasting BG and HbA1c were assessed at 3, 6 and 12 months and at the last visit to our centre.

RESULTS

Immediately following renal transplantation, capillary BG was 12.2 ± 3.8 mmol/L. On day 1 (D1), fasting BG was 9.9 ± 4.3 mmol/L and decreased to 6.0 ± 1.5 mmol/L on D3. The CGM-reported mean 24-h BG (mmol/L) was 10.2±2.4 on D1, 7.7 ± 1.3 on D2 and 7.5 ± 1.1 on D3. From D1 to D4, 43% of patients spent>12h/day with BG levels>7.7 mmol/L. While morbidity during the 3 months following transplantation appeared unrelated to BG, the first post-transplantation capillary BG measurement and fasting BG on D1 tended to be higher in patients who developed diabetes 3 months later. Tacrolimus treatment was associated with a higher incidence of dysglycaemia at 3 and 6 months. After a mean follow-up of 72 months, NODAT was frequently seen (18.6%), and was associated with tacrolimus medication (P<0.01) and a higher rate of renal transplantation failure (RR: 3.6, P<0.02).

CONCLUSION

Hyperglycaemia appears to be a nearly constant characteristic immediately following transplantation in non-diabetic kidney recipients. Higher BG values could identify patients at risk for later post-transplant diabetes and graft failure.

Detection of glycemic abnormalities in adolescents with beta thalassemia using continuous glucose monitoring and oral glucose tolerance in adolescents and young adults with β-thalassemia major: Pilot study

BACKGROUND

Both insulin deficiency and resistance are reported in patients with β-thalassemia major (BTM). The use of continuous blood glucose monitoring (CGM), among the different methods for early detection of glycemic abnormalities, has not been studied thoroughly in these adolescents.

MATERIALS AND METHODS

To assess the oralglucose tolerance (OGT) and 72-h continuous glucose concentration by the continuous glucose monitoring system (CGMS) and calculate homeostatic model assessment (HOMA), and the quantitative insulin sensitivity check index (QUICKI) was conducted in 16 adolescents with BTM who were receiving regular blood transfusions every 2-4 weeks and iron-chelation therapy since early childhood.

RESULTS

SIXTEEN ADOLESCENTS WITH BTM (AGE: 19.75 ± 3 years) were investigated. Using OGTT, (25%) had impaired fasting blood (plasma) glucose concentration (BG) (>5.6 mmol/L). 2-h after the glucose load, one of them had BG = 16.2 mmol/L (diabetic) and two had impaired glucose tolerance (IGT) (BG > 7.8 and <11.1 mmol/L). Monitoring the maximum (postprandial) BG using CGMS,4 adolescents were diagnosed with diabetes (25%) (BG >11.1 mmol/L) and 9 with IGT (56%). HOMA and QUICKI revealed levels <2.6 (1.6 ± 0.8) and >0.33 (0.36 ± 0.03), respectively, ruling out significant insulin resistance in these adolescents. There was a significant negative correlation between the β-cell function (B%) on one hand and the fasting and the 2-h BG (r=-0.6, and - 0.48, P < 0.01, respectively) on the other hand. Neither fasting serum insulin nor c-peptide concentrations were correlated with fasting BG or ferritin levels. The average and maximum blood glucose levels during CGM were significantly correlated with the fasting BG (r = 0.68 and 0.39, respectively, with P < 0.01) and with the BG at 2-hour after oral glucose intake (r = 0.87 and 0.86 respectively, with P < 0.001). Ferritin concentrations were correlated with the fasting BG and the 2-h blood glucose levels in the OGTT (r = 0.52, and r = 0.43, respectively, P < 0.01) as well as with the average BG recorded by CGM (r = 0.75, P < 0.01).

CONCLUSION

CGM has proven to be superior to OGTT for the diagnosis of glycemic abnormalities in adolescents with BTM. Defective β-cell function rather than insulin resistance appeared to be the cause for these abnormalities.

Management of blood glucose in patients with stroke

Stroke is a leading cause of death worldwide and the most common cause of long-term disability amongst adults, more particularly in patients with diabetes mellitus and arterial hypertension. Increasing evidence suggests that disordered physiological variables following acute ischaemic stroke, especially hyperglycaemia, adversely affect outcomes. Post-stroke hyperglycaemia is common (up to 50% of patients) and may be rather prolonged, regardless of diabetes status. A substantial body of evidence has demonstrated that hyperglycaemia has a deleterious effect upon clinical and morphological stroke outcomes. Therefore, hyperglycaemia represents an attractive physiological target for acute stroke therapies. However, whether intensive glycaemic manipulation positively influences the fate of ischaemic tissue remains unknown. One major adverse event of management of hyperglycaemia with insulin (either glucose-potassium-insulin infusions or intensive insulin therapy) is the occurrence of hypoglycaemia, which can also induce cerebral damage. Novel insights into post-stroke hyperglycaemia management have been derived from continuous glucose monitoring systems (CGMS). This article aims: 1) to describe the adverse effects of hyperglycaemia following acute ischaemic stroke and the risk associated with iatrogenic hypoglycaemia; 2) to summarise the evidence from current glucose-lowering treatment trials; and 3) to show the usefulness of CGMS in both non-diabetic and diabetic patients with acute stroke.

Real-time continuous glucose monitoring in critically ill patients: a prospective randomized trial

OBJECTIVE To evaluate the impact of real-time continuous glucose monitoring (CGM) on glycemic control and risk of hypoglycemia in critically ill patients. RESEARCH DESIGN AND METHODS A total 124 patients receiving mechanical ventilation were randomly assigned to the real-time CGM group (n = 63; glucose values given every 5 min) or to the control group (n = 61; selective arterial glucose measurements according to an algorithm; simultaneously blinded CGM) for 72 h. Insulin infusion rates were guided according to the same algorithm in both groups. The primary end point was percentage of time at a glucose level <110 mg/dl. Secondary end points were mean glucose levels and rate of severe hypoglycemia (<40 mg/dl). RESULTS Percentage of time at a glucose level <110 mg/dl (59.0 +/- 20 vs. 55.0 +/- 18% in the control group, P = 0.245) and the mean glucose level (106 +/- 18 vs. 111 +/- 10 mg/dl in the control group, P = 0.076) could not be improved using real-time CGM. The rate of severe hypoglycemia was lower in the real-time CGM group (1.6 vs. 11.5% in the control group, P = 0.031). CGM reduced the absolute risk of severe hypoglycemia by 9.9% (95% CI 1.2-18.6) with a number needed to treat of 10.1 (95% CI 5.4-83.3). CONCLUSIONS In critically ill patients, real-time CGM reduces hypoglycemic events but does not improve glycemic control compared with intensive insulin therapy guided by an algorithm.