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Principal Investigator: Peter D Reaven
Organization: PHOENIX VA HEALTH CARE SYSTEM
Fiscal Year: 2024
Funding agency: Veterans Affairs
Summary: Continuous glucose monitoring (CGM) is increasing rapidly in the Veterans Administration Health
Care System (VAHCS). Experience with CGM is greatly modifying our concepts of glucose control and our
understanding of how to define and achieve optimal glucose goals. Most available data on CGM has been
derived from short-term small trials or observational studies conducted in classic early onset T1D patients and
have illustrated the value of CGM in these patients with respect to glucose lowering and reduced hypoglycemia.
However, much less is known about benefits of CGM in T1D that develops later in life nor in the far more frequent
setting of T2D. There is also very little known about CGM related effects on the many serious, debilitating and
costly diabetes complications that are so prevalent in both T1D and T2D. Because use of CGM has substantial
financial costs and requires extensive time on the part of patients, physicians, nurses and other staff participating
in diabetes care to implement and sustain CGM, we need to better understand how to best use CGM and what
is gained from it. Our preliminary data demonstrate we can extract clinical and demographic information for
T1D and T2D patients and evaluate the benefits of CGM initiation on short-term glucose control and several
adverse outcomes. There is also a striking signal of potential benefits on major comorbidities such as renal
disease, cardiovascular disease and even mortality. Now we propose to expand the years of data collection and
follow-up time to directly focus on the benefits of CGM initiation on long-term clinically important outcomes. There
will be three main aims for this project. In Aim 1, we will assess in T1D and T2D within the VAHCS the effect of
CGM initiation (compared with matched nonCGM users) on the occurrence of ER or hospital admissions for
hypoglycemia and hyperglycemia and all-cause hospital admissions over 4 years. In all three aims we will use
overlap propensity score weighting to balance CGM users and nonusers and will conduct multiple sensitivity
analyses to assess and adjust for potential bias in matching. As a secondary analyses we will compare the
effects in T1D and T2D of initiating CGM on long-term glucose control. We will also examine baseline features,
such as age, racial/ethnic identity, glycemic control, hypoglycemic risk, complication status, CGM type as well
as patterns of CGM use to identify subgroups with differential long-term benefits of CGM on these outcomes. In
Aim 2, we will assess in T1D and T2D the effects of CGM on development of renal disease and diabetes
complications. To achieve this aim, we will compare the effects in T1D and T2D of initiating CGM (vs. nonCGM
users) on development of a composite outcome indicating severe renal disease and assess change in a validated
diabetes complication index score. As in Aim 1, we will also attempt to identify subgroups with differential benefits
of CGM on these outcomes. We will also explore the contribution of improved HbA1c to CGM related
improvements in outcomes. Aim 3 will build on promising preliminary data to examine the effects of CGM on a
cardiovascular disease composite outcome (myocardial infarction, ischemic stroke and heart failure) and all-
cause mortality. We will initially compare CGM users and nonusers in combined cohorts of T1D and T2D patients
to ensure sufficient event numbers to detect small group differences, but will subsequently examine them in
distinct groups. We will also conduct subgroup comparisons as described for Aims 1 and 2. To minimize
differences in extent of follow-up between individuals we will initially limit follow-up time to 4 years, although
secondary analyses will explore extending the follow-up time to 6 years where appropriate. This study will clarify
the range of benefits that can be obtained with longer-term use of CGM, and determine if these extend well
beyond improvements in glycemic control. These aims will determine whether CGM initiation may reduce
multiple relevant outcomes and how to best identify these individuals. Results from this study could add
prevention of serious clinical outcomes to the rationale for initiating CGM. Overall, the study will advance our
ability to apply precision medicine in our application of CGM to both later-onset T1D and T2D patients.
Terms: <Accident and Emergency department><Active Follow-up><Adult-Onset Diabetes Mellitus><Adverse Experience><Adverse event><Age><Apoplexy><Brain Vascular Accident><Brittle Diabetes Mellitus><Cardiac infarction><Cardiovascular><Cardiovascular Body System><Cardiovascular Diseases><Cardiovascular Organ System><Cardiovascular system><Caring><Cell Communication and Signaling><Cell Signaling><Cerebral Stroke><Cerebrovascular Apoplexy><Cerebrovascular Stroke><Cessation of life><Characteristics><Clinical><Complication><Complications of Diabetes Mellitus><Continuous Glucose Monitor><D-Glucose><Data><Data Collection><Data Set><Death><Decision Making><Development><Dextrose><Diabetes Complications><Diabetes Mellitus><Diabetes-Related Complications><Diabetic Complications><Disease Outcome><Emergency Department><Emergency room><Ensure><Equilibrium><Ethnic Origin><Ethnicity><Event><Financial cost><Fostering><Frequencies><Glucose><Glycohemoglobin A><Glycosylated hemoglobin A><Goals><Hb A1><Hb A1a+b><Hb A1c><HbA1><HbA1c><Health><Health Care Providers><Health Care Systems><Health Personnel><Healthcare Providers><Healthcare Systems><Healthcare worker><Heart Vascular><Heart failure><Hemoglobin A(1)><Hospital Admission><Hospitalization><Humulin R><Hyperglycemia><Hypoglycemia><IDDM><Individual><Insulin><Insulin-Dependent Diabetes Mellitus><Intracellular Communication and Signaling><Ischemic Heart><Ischemic Heart Disease><Ischemic Stroke><Ischemic myocardium><Juvenile-Onset Diabetes Mellitus><Ketosis-Prone Diabetes Mellitus><Ketosis-Resistant Diabetes Mellitus><Kidney Diseases><Life><Long-Term Effects><Longterm Effects><Maturity-Onset Diabetes Mellitus><Myocardial Infarct><Myocardial Infarction><Myocardial Ischemia><NIDDM><Nephropathy><Non-Insulin Dependent Diabetes><Non-Insulin-Dependent Diabetes Mellitus><Noninsulin Dependent Diabetes><Noninsulin Dependent Diabetes Mellitus><Novolin R><Nurses><Observation research><Observation study><Observational Study><Observational research><Outcome><Patients><Pattern><Perception><Physicians><Prevention><Race><Races><Regimen><Regular Insulin><Renal Diabetes><Renal Disease><Renal Glycosuria><Risk><Serious Adverse Event><Severe Adverse Event><Signal Transduction><Signal Transduction Systems><Signaling><Slow-Onset Diabetes Mellitus><Stable Diabetes Mellitus><Stroke><Subgroup><Sudden-Onset Diabetes Mellitus><T1 DM><T1 diabetes><T1D><T1DM><T2 DM><T2D><T2DM><Time><Type 1 Diabetes Mellitus><Type 1 diabetes><Type 2 Diabetes Mellitus><Type 2 diabetes><Type I Diabetes Mellitus><Type II Diabetes Mellitus><Type II diabetes><Veterans Health Administration><Veterans Health Affairs><active followup><adult onset diabetes><adverse consequence><adverse outcome><ages><balance><balance function><biological signal transduction><blood glucose regulation><brain attack><cardiac failure><cardiac infarct><cardiac ischemia><cardiovascular disorder><cerebral vascular accident><cerebrovascular accident><circulatory system><clinical development><clinical relevance><clinically relevant><co-morbid><co-morbidity><cohort><comorbidity><continuous blood glucose monitor><continuous blood sugar monitor><continuous glucose measurement><continuous sugar monitor><coronary attack><coronary infarct><coronary infarction><coronary ischemia><cost><developmental><diabetes><early onset><ethnic identity><experience><follow up><follow-up><followed up><followup><glucose control><glucose homeostasis><glucose regulation><glycemic control><health care personnel><health care worker><health provider><health record><health workforce><healthcare personnel><heart attack><heart infarct><heart infarction><heart ischemia><hemoglobin A1c><high risk><hospitalization rates><hyperglycemic><hypoglycemic><hypoglycemic episodes><improved><indexing><insulin dependent diabetes><insulin dependent diabetes mellitus onset><insulin dependent type 1><juvenile diabetes><juvenile diabetes mellitus><ketosis prone diabetes><ketosis resistant diabetes><kidney disorder><maturity onset diabetes><medical personnel><monetary cost><mortality><myocardial ischemia/hypoxia><myocardium ischemia><nurse><precision medicine><precision-based medicine><prevent><preventing><racial><racial background><racial origin><renal disorder><secondary analysis><serious adverse experience><serious adverse reaction><stroked><strokes><treatment provider><type 1 and type 2 diabetes><type 1 diabetes onset><type 2 DM><type I and type II diabetes><type I diabetes><type II DM><type one diabetes><type two diabetes>