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PERL Continuous Glucose Monitoring (CGM) Study

Completed
Conditions
Diabetic Nephropathies
Interventions
Other: Mean blood glucose
Other: Blood glucose CV
Other: % time 70-180 mg/dL
Other: % time below 54 mg/dL
Other: % time above 180 mg/dL
Other: % time above 250 mg/dL
Other: MAGE (Mean amplitude of glucose excursions)
Other: LBGI (Low Blood Glucose Index)
Other: HBGI (High Blood Glucose Index)
Drug: Placebo
Drug: Allopurinol
Registration Number
NCT03334318
Lead Sponsor
Joslin Diabetes Center
Brief Summary

Seven-point capillary profiles have shown that mean glucose correlates with both diabetic retinopathy and nephropathy risk. However, there remains great controversy as to whether the degree of variability around mean glucose may also contribute to these microvascular complications. The PERL trial (NCT02017171), testing whether treatment with allopurinol can slow down kidney function loss in type 1 diabetes, provides a unique opportunity to assess the role of glycemic variability in the progression of diabetic kidney disease in individuals who already have mild to moderate kidney disease. By applying Continuous Glucose Monitoring (CGM) in the PERL Study population, the investigators will be able to better understand how metrics of glycemia (mean, time above and below range, and various measures of variability) are associated with renal outcomes in the PERL population as a whole, but also in important subgroups (e.g., albuminuric vs. normoalbuminuric subjects with ongoing GFR decline, allopurinol vs. placebo arms). The nvestigators also aim to obtain precise information on the range of blood glucose corresponding to any given HbA1c value in this population since previous studies generally excluded patients with renal disease.

Detailed Description

Participants who consent to the study will have an Abbott Freestyle Libre Pro sensor placed on the back of their upper arm at their first PERL visit after this ancillary study has begun and at all subsequent PERL Visits. The sensor will be continuously worn by participants for 14 days. At the end of the 14 days, the sensor will be removed and mailed by the participant to the Coordinating center. Since subjects are at various stages of the PERL protocol, the number of remaining visits at which the CGM will be applied will vary among subjects.

STUDY AIMS

1. To assess the effect of glycemic variability, as measured by the coefficient of variation of CGM glucose (CV, the ratio of standard deviation and the mean of CGM glucose values), on the PERL renal functional endpoint (iohexol GFR at the end of study).

2. To assess the effect of other glycemic parameters measured by CGM (mean glucose, % time 70-180 mg/dL, % time below 54 mg/dL, % time below 70 mg/dL, % time above 180 mg/dL, % time above 250 mg/dL, mean amplitude of glucose excursions \[MAGE\], low blood glucose index \[LBGI\], high blood glucose index \[HBGI\]) on the PERL renal functional endpoint.

3. To assess the relationship between CGM-measured glycemic parameters and HbA1c at various levels of renal function.

4. To compare the effects of CGM metrics on the PERL renal endpoint and the corresponding effect of HbA1c.

5. To assess the effect of allopurinol treatment on all of the different glycemic metrics including HbA1c, CV, etc. and on their association with the PERL renal endpoint.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
175
Inclusion Criteria

• Being an active participant in the PERL clinical trial

Read More
Exclusion Criteria
  • Having completed PERL Visit 16
  • Pregnancy
  • History of skin reactions in relation to the application of Abbott Freestyle Libre Pro
Read More

Study & Design

Study Type
OBSERVATIONAL
Study Design
Not specified
Arm && Interventions
GroupInterventionDescription
Placebo-treated% time below 54 mg/dLParticipants in the PERL Clinical Trial (NCT02017171) randomized to placebo
Placebo-treated% time above 180 mg/dLParticipants in the PERL Clinical Trial (NCT02017171) randomized to placebo
Placebo-treated% time above 250 mg/dLParticipants in the PERL Clinical Trial (NCT02017171) randomized to placebo
Placebo-treatedMAGE (Mean amplitude of glucose excursions)Participants in the PERL Clinical Trial (NCT02017171) randomized to placebo
Placebo-treatedLBGI (Low Blood Glucose Index)Participants in the PERL Clinical Trial (NCT02017171) randomized to placebo
Placebo-treatedHBGI (High Blood Glucose Index)Participants in the PERL Clinical Trial (NCT02017171) randomized to placebo
Allopurinol-treatedMean blood glucoseParticipants in the PERL Clinical Trial (NCT02017171) randomized to allopurinol
Placebo-treatedPlaceboParticipants in the PERL Clinical Trial (NCT02017171) randomized to placebo
Allopurinol-treatedBlood glucose CVParticipants in the PERL Clinical Trial (NCT02017171) randomized to allopurinol
Allopurinol-treated% time 70-180 mg/dLParticipants in the PERL Clinical Trial (NCT02017171) randomized to allopurinol
Allopurinol-treated% time below 54 mg/dLParticipants in the PERL Clinical Trial (NCT02017171) randomized to allopurinol
Allopurinol-treated% time above 180 mg/dLParticipants in the PERL Clinical Trial (NCT02017171) randomized to allopurinol
Allopurinol-treated% time above 250 mg/dLParticipants in the PERL Clinical Trial (NCT02017171) randomized to allopurinol
Allopurinol-treatedMAGE (Mean amplitude of glucose excursions)Participants in the PERL Clinical Trial (NCT02017171) randomized to allopurinol
Placebo-treatedMean blood glucoseParticipants in the PERL Clinical Trial (NCT02017171) randomized to placebo
Placebo-treatedBlood glucose CVParticipants in the PERL Clinical Trial (NCT02017171) randomized to placebo
Placebo-treated% time 70-180 mg/dLParticipants in the PERL Clinical Trial (NCT02017171) randomized to placebo
Allopurinol-treatedLBGI (Low Blood Glucose Index)Participants in the PERL Clinical Trial (NCT02017171) randomized to allopurinol
Allopurinol-treatedHBGI (High Blood Glucose Index)Participants in the PERL Clinical Trial (NCT02017171) randomized to allopurinol
Allopurinol-treatedAllopurinolParticipants in the PERL Clinical Trial (NCT02017171) randomized to allopurinol
Primary Outcome Measures
NameTimeMethod
iGFR at the end of the PERL trialWeek 164 of the PERL trial

Glomerular filtration rate (GFR) at the end of the PERL trial, measured by the plasma clearance of non-radioactive iohexol (iGFR) and adjusted for the iGFR at baseline.

Secondary Outcome Measures
NameTimeMethod
HbA1c at week 142 of the PERL trialWeek 142 of the PERL Trial

Hba1c value at week 142 of the PERL trial

HbA1c at week 80 of the PERL trialWeek 80 of the PERL Trial

Hba1c value at week 80 of the PERL trial

HbA1c at week 96 of the PERL trialWeek 96 of the PERL Trial

Hba1c value at week 96 of the PERL trial

HbA1c at week 112 of the PERL trialWeek 112 of the PERL Trial

Hba1c value at week 112 of the PERL trial

HbA1c at week 128 of the PERL trialWeek 128 of the PERL Trial

Hba1c value at week 128 of the PERL trial

% time above 250 mg/dLFrom week 80 to week 164 of the PERL trial

Percentage of time with blood glucose above 250 mg/dL (as measured by continuous glucose monitoring)

HbA1c at week 156 of the PERL trialWeek 156 of the PERL Trial

Hba1c value at week 156 of the PERL trial

HbA1c at week 164 of the PERL trialWeek 164 of the PERL Trial

Hba1c value at week 164 of the PERL trial

Mean blood glucoseFrom week 80 to week 164 of the PERL trial

Mean of blood glucose values measured by continuous glucose monitoring

CV (coefficient of variation) of blood glucoseFrom week 80 to week 164 of the PERL trial

Coefficient of variation of blood glucose values measured by continuous glucose monitoring

% time 70-180 mg/dLFrom week 80 to week 164 of the PERL trial

Percentage of time with blood glucose in the 70-180 mg/dL range (as measured by continuous glucose monitoring)

% time below 54 mg/dLFrom week 80 to week 164 of the PERL trial

Percentage of time with blood glucose below 54 mg/dL (as measured by continuous glucose monitoring)

% time above 180 mg/dLFrom week 80 to week 164 of the PERL trial

Percentage of time with blood glucose above 180 mg/dL (as measured by continuous glucose monitoring)

MAGE (Mean amplitude of glucose excursions)From week 80 to week 164 of the PERL trial

Mean amplitude of glucose excursions as measured by continuous glucose monitoring

LBGI (Low blood glucose index)From week 80 to week 164 of the PERL trial

Low blood glucose index based on blood glucose values measured by continuous glucose monitoring

HBGI (High blood glucose index)From week 80 to week 164 of the PERL trial

High blood glucose index based on blood glucose values measured by continuous glucose monitoring

Trial Locations

Locations (19)

ICAHN School of Medicine at Mount Sinai

🇺🇸

New York, New York, United States

Washington University

🇺🇸

Saint Louis, Missouri, United States

Unversity of Calgary

🇨🇦

Calgary, Alberta, Canada

Barbara Davis Center / University of Colorado Denver

🇺🇸

Aurora, Colorado, United States

Northwestern University Feinberg School of Medicine

🇺🇸

Chicago, Illinois, United States

Emory University - Grady Memorial Hospital

🇺🇸

Atlanta, Georgia, United States

Brehm Center for Diabetes Research / University of Michigan

🇺🇸

Ann Arbor, Michigan, United States

Henry Ford Health System

🇺🇸

Detroit, Michigan, United States

University of Minnesota

🇺🇸

Minneapolis, Minnesota, United States

SUNY Upstate Medical University

🇺🇸

Syracuse, New York, United States

UT Southwestern Dallas

🇺🇸

Dallas, Texas, United States

Virginia Mason Medical Center

🇺🇸

Seattle, Washington, United States

University of Washington

🇺🇸

Seattle, Washington, United States

University of Toronto

🇨🇦

Toronto, Ontario, Canada

Joslin Diabetes Center

🇺🇸

Boston, Massachusetts, United States

BC Diabetes

🇨🇦

Vancouver, British Columbia, Canada

Providence Sacred Heart Medical Center

🇺🇸

Spokane, Washington, United States

Albert Einstein College of Medicine / Montefiore Medical Center

🇺🇸

Bronx, New York, United States

University of Alberta

🇨🇦

Edmonton, Alberta, Canada

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