An observational study in HbA1c, Peritoneal Diseases and Glycated Albumin, sponsored by Rigshospitalet, Denmark. Completed at 5 sites in Denmark. Open to participants aged 18 Years to 90 Years. Per ClinicalTrials.gov, last updated 2020-09-29.
Sponsored by Rigshospitalet, Denmark · Observational
The aim is to investigate the correlation between mean glucose measured by continuous glucose monitoring (CGM) and mean glucose estimated from glycated haemoglobin A1c (HbA1c) in persons with type 2 diabetes undergoing peritoneal dialysis compared with patients with type 2 diabetes and normal renal function. Furthermore, the aim is to compare CGM and HbA1c with glycated albumin and fructosamine.
Background:
In persons with type 2 diabetes, glycated haemoglobin A1c (HbA1c) is used as an indirect measure of the mean glucose over the past 3-4 months. The normal range of HbA1c and the correlation to the mean glucose has been determined from studies in subjects without severe chronic kidney disease.
In persons with end-stage renal disease (ESRD) and type 2 diabetes, HbA1c has been shown in small studies to underestimate mean glucose when compared with continuous glucose monitoring (CGM) or alternative glycaemic markers such as glycated albumin or fructosamine. The cause of a falsely low HbA1c in persons with ESRD and diabetes is not clear, but adjuvant erythropoietin treatment and iron infusion increase erythropoiesis, thus increasing the number of new non-glycated erythrocytes that are thought to lower HbA1c. Furthermore, the erythrocyte life span was found to be decreased in individuals receiving hemodialysis and peritoneal dialysis, which may also contribute to a reduction in HbA1c.
CGM is an alternative to HbA1c in glycaemic monitoring and measures interstitial glucose that calibrates with blood glucose within minutes. CGM measures interstitial glucose every five minutes for up to eight days (Medtronic's Ipro2). Studies of persons with type 1 diabetes and CGM measurements performed over three months showed that approximately two-weeks of CGM measurements correlated to HbA1c. When CGM was performed beyond 14 days, the correlation between the mean glucose from CGM and HbA1c improved only modestly.
Values of CGM measurements also provide a basis for monitoring glycaemic variability, time-in-range and hypoglycaemic episodes. For persons with diabetes undergoing peritoneal dialysis, there are only a few studies validating HbA1c and none have been prospective with a control group over a long period of time. A retrospective study of 60 persons with diabetes and in peritoneal dialysis (without control group) found a significant correlation between HbA1c and mean interstitial glucose as measured by CGM (r = 0.48, P≤0.0001). A prospective study of 25 persons with diabetes and in peritoneal dialysis (without control group) also found a significant correlation (r = 0.51, P≤0.01). A study of three persons with diabetes and in peritoneal dialysis (without control group) found that HbA1c compared to CGM underestimated mean glucose in one, but overestimated mean glucose in the other two. However, all three studies did not include a control group and had few days of CGM measurements, which collectively mean that the evidence for the use of HbA1c in this patient group is sparse.
In a study of peritoneal dialysis subjects with diabetic nephropathy (n = 1296), 17.7% had normal HbA1c and were without antidiabetic treatment. When the same study included glycated albumin, 10.9% were found to have normal HbA1c, normal glycated albumin (defined as less than 16%) and were without antidiabetic medication. The study concluded that normal HbA1c alone overestimates the prevalence of burnt-out diabetes.
The uncertainty associated with HbA1c in persons with type 2 diabetes undergoing peritoneal dialysis is a problem both in terms of diagnosing and treating diabetes appropriately. CGM, glycated albumin and fructosamine are independent of erythrocyte turnover thus allowing for a validation of HbA1c in this group of patients.
Objective:
To investigate the correlation between mean glucose measured by continuous glucose monitoring (CGM) and mean glucose estimated from glycated haemoglobin A1c (HbA1c) in persons with type 2 diabetes undergoing peritoneal dialysis compared with a control group of persons with type 2 diabetes and normal renal function.
Method:
Prospective case-control study over 16 days with 26 persons in each group. The case group consist of persons with type 2 diabetes undergoing peritoneal dialysis and the control group consists of persons with type 2 diabetes with normal renal function (defined as an estimated glomerular filtration rate (eGFR) above 60 ml/min and urine albumin-creatinine ratio below 300mg/g). CGM is performed for a maximum of 16 days. On visit 1 (day 0), CGM is performed for 8 days and visit 2 (day 8) (+7/-4 days), CGM is performed for another 8 days. Glycaemic markers are measured at baseline and on visit 3 (final day of the study). At least 12 days of CGM must be completed for each person. Data is collected using REDcap.
Statistics:
The null hypothesis is that there is no difference in the ratio between the two groups measured as mean glucose concentration measured over 16 days at CGM (mmol / L) divided by the estimated glucose concentration from HbA1c (mmol / L) measured at day 16.
The alternative hypothesis is that there is a 17% difference between groups for the ratio of mean glucose concentration measured by CGM (mmol / L) divided by the mean glucose concentration from HbA1c (mmol / L). In a pilot study of persons with type 2 diabetes and dialysis dependent ESRD compared with persons with normal renal function, a 17% difference was found in the ratio between the two groups. In a two-sided unpaired t-test with α = 0.05, SD = 1.17 and power of 90%, a sample size of 24 individuals in each group will show a significant difference. A drop of approximately 10% is expected and a total of 26 are included in each group.
Rigshospitalet, Denmark is the lead sponsor of 1,017 studies on the registry; 183 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Total of 52 participants with 26 in each group.
Case group: 26 patients on peritoneal dialysis with type 2 diabetes.
Control group: 26 patients with type 2 diabetes and normal renal function (defined as eGFR >60 ml/min and with Urine Albumin-to-Creatinine Ratio below 300mg/g.
The patients are recruited from the department of Endocrinology or Nephrology at Rigshospitalet, from Herlev Hospital department of Nephrology, Steno Diabetes Center Copenhagen, Hillerød Hospital department of Nephrology and Roskilde Hospital department of Nephrology.
Inclusion criteria for case group (on peritoneal dialysis with type 2 diabetes):
Exclusion criteria for case group (on peritoneal dialysis with type 2 diabetes):
Inclusion criteria for control group (type 2 diabetes and normal renal function):
Exclusion criteria for control group (type 2 diabetes and normal renal function):
Severe infections
*Inclusion with diagnosis of type 2 diabetes was defined as ongoing antidiabetic treatment and previously diagnosed with type 2 diabetes according to the following criteria:
Case group with type 2 diabetes undergoing peritoneal dialysis for at least 3 months.
Device: Continuous glucose monitoring · Diagnostic Test: Glycaemic markers
Control group with type 2 diabetes and no nephropathy (defined as eGFR above 60ml/min and UACR below 300mg/g).
Device: Continuous glucose monitoring · Diagnostic Test: Glycaemic markers
Continuous glucose monitoring over 16 days
Measurement of HbA1c, glycated albumin and fructosamine.
HbA1c evaluated by the total mean glucose from continuous glucose monitoring
Difference between the two groups in the ratio of mean glucose measured by continuous glucose monitoring (measured over 16 days) divided by the estimated mean blood glucose from HbA1c (measured at the final visit). For each person at least 12 days of CGM must be completed.
Time frame: 16 days
Glycated albumin
Correlation between mean glucose from continuous glucose monitoring (measured over 16 days) and glycated albumin ((%) measured at the final visit).
Time frame: 16 days
Fructosamine
Correlation between mean glucose from continuous glucose monitoring (measured over 16 days) and fructosamine ((μmol/l) measured at the final visit).
Time frame: 16 days
Standard deviation
Standard deviation for glycaemic variability measured by continuous glucose monitoring in both groups.
Time frame: 16 days
Coefficient variation
Coefficient variation for glycaemic variability measured by continuous glucose monitoring in both groups.
Time frame: 16 days
Low Blood Glucose Index
Low Blood Glucose Index for glycaemic variability measured by continuous glucose monitoring in both groups. Is a risk index for predicting hypoglycaemia.
Time frame: 16 days
High Blood Glucose Index
High Blood Glucose Index for glycaemic variability measured by continuous glucose monitoring in both groups. Is a risk index for predicting hyperglycaemia.
Time frame: 16 days
Time in hypoglycaemic range below 3.0 mmol/l
Time in hypoglycaemic range(%) below 3.0 mmol/l evaluated by continuous glucose monitoring .
Time frame: 16 days
Time in hypoglycaemic range below 3.9 mmol/l to 3.0 mmol/l
Time in hypoglycaemic range(%) below 3.9 mmol/l to 3.0 mmol/l evaluated by continuous glucose monitoring .
Time frame: 16 days
Time in hyperglycaemic range above 10.0 mmol/l
Time in hyperglycaemic range(%) above 10.0 mmol/l evaluated by continuous glucose monitoring .
Time frame: 16 days
Time in hyperglycaemic range above 13.9 mmol/l
Time in hyperglycaemic range(%) above 13.9 mmol/l evaluated by continuous glucose monitoring
Time frame: 16 days
Hypoglycaemic events
Beginning of a CGM event is defined as a reading below the threshold for at least 15 min for either a value below 3.0 mmol/l or between 3.9 mmol/l to 3.0 mmol/l. The end of a CGM event is defined as a reading for 15 min above 3.9 mmol/l.
Time frame: 16 days
This study is completed, as verified in Sep 2020. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Peritoneal Diseases
Rigshospitalet, Denmark