Increased Hemoglobin A1c Time in Range Reduces Adverse Health Outcomes in Older Adults With Diabetes

Relationship Between Glycosylated Hemoglobin Variability and the Severity of Coronary Artery Disease in Patients With Type 2 Diabetes Mellitus

Background: Glycosylated hemoglobin (HbA1c) variability is a risk factor for cardiovascular complications in patients with Type 2 diabetes mellitus (T2DM), but its relationship with the severity of coronary artery disease (CAD) is unclear. Methods: Patients with T2DM who underwent coronary angiography due to angina were enrolled. HbA1c variability was expressed as coefficient of variation (CV), standard deviation (SD), variability independent of mean (VIM), and time in range (TIR). The severity of CAD was expressed by the number of involved vessels and Gensini score. Multivariate regression models were constructed to test the relationship between HbA1c variability, number of involved vessels, and the Gensini score, followed by linear regression analysis. Results: A total of 147 patients were included. In multivariate analysis, VIM-HbA1c (OR = 2.604; IQR: 1.15, 5.90; r = 0.026) and HbA1cTIR (OR = 0.13; IQR: 0.04, 0.41; r < 0.001) were independent risk factors for the number of involved vessels. After adjustment, HbA1cTIR (OR = 0.01; IQR: 0.002, 0.04; r < 0.001), SD-HbA1c (OR = 4.12, IQR: 1.64, 10.35; r = 0.001), CV-HbA1c (OR = 1.41, IQR: 1.04, 1.92; r = 0.007), and VIM-HbA1c (OR = 3.26; IQR: 1.43, 7.47; r = 0.003) were independent risk factors for the Gensini score. In the linear analysis, the Gensini score was negatively correlated with HbA1cTIR (β = -0.629; r < 0.001) and positively correlated with SD-HbA1c (β = 0.271; r = 0.001) and CV-HbA1c (β = 0.176; r = 0.033). After subgroup analysis, HbA1cTIR was a risk factor for the number of involved vessels. The Gensini score was negatively correlated with HbA1cTIR and positively correlated with SD-HbA1c at subgroups of subjects with a mean HbA1c ≤ 7%. Conclusions: Our analysis indicates that HbA1c variability, especially HbA1cTIR, plays a role for the severity of CAD in patients with T2DM. HbA1c variability may provide additional information and require management even at the glycemic target. Translational Aspects: Studies have shown that HbA1c variability is related to cardiovascular complications. Further, we explore the correlation between HbA1c variability and the severity of CAD. HbA1c variability is a risk factor for coronary stenosis in T2DM. It may be a potential indicator reflecting glycemic control for the prevention and treatment of cardiovascular complications.

Glycated Hemoglobin A1c Time in Range and Dementia in Older Adults With Diabetes

Importance

Individuals with diabetes commonly experience Alzheimer disease and related dementias (ADRD). Factors such as hypoglycemia, hyperglycemia, and glycemic variability have been associated with increased risk of ADRD. Traditional glycemic measures, such as mean glycated hemoglobin A1c (HbA1c), may not identify the dynamic and complex pathophysiologic factors in the association between diabetes and ADRD. The HbA1c time in range (TIR) is a previously developed measure of glycemic control that expresses HbA1c stability over time within specific ranges. This measure may inform the current understanding of the association between glucose levels over time and ADRD incidence.

Objective

To examine the association between HbA1c TIR and incidence of ADRD in older veterans with diabetes.

Design, Setting, and Participants

The study sample for this cohort study was obtained from administrative and health care utilization data from the Veterans Health Administration and Medicare from January 1, 2004, to December 31, 2018. Veterans 65 years or older with diabetes were assessed. Participants were required to have at least 4 HbA1c tests during the 3-year baseline period, which could start between January 1, 2005, and December 31, 2014. Data analysis was conducted between July and December 2023.

Main Outcomes and Measures

Hemoglobin A1c TIR was calculated as the percentage of days during baseline in which HbA1c was in individualized target ranges based on clinical characteristics and life expectancy, with higher HbA1c TIR viewed as more favorable. The association between HbA1c TIR and ADRD incidence was estimated. Additional models considered ADRD incidence in participants who were above or below HbA1c target ranges most of the time.

Results

The study included 374 021 veterans with diabetes (mean [SD] age, 73.2 [5.8] years; 369 059 [99%] male). During follow-up of up to 10 years, 41 424 (11%) developed ADRD. Adjusted Cox proportional hazards regression models showed that lower HbA1c TIR was associated with increased risk of incident ADRD (HbA1c TIR of 0 to <20% compared with ≥80%: hazard ratio, 1.19; 95% CI, 1.16-1.23). Furthermore, the direction of out-of-range HbA1c levels was associated with incident ADRD. Having greater time below range (≥60%, compared with ≥60% TIR) was associated with significantly increased risk (hazard ratio, 1.23; 95% CI, 1.19-1.27). Findings remained significant after excluding individuals with baseline use of medications associated with hypoglycemia risk (ie, insulin and sulfonylureas) or with hypoglycemia events.

Conclusions and Relevance

In this study of older adults with diabetes, increased HbA1c stability within patient-specific target ranges was associated with a lower risk of ADRD. Lower HbA1c TIR may identify patients at increased risk of ADRD.

The association between glycated hemoglobin levels and long-term prognosis in patients with diabetes and triple-vessel coronary disease across different age groups: A cohort study

AIM

Our study aimed to investigate the correlation between glycated hemoglobin (HbA1c) and adverse prognostic events in patients with diabetes and triple-vessel coronary disease (TVD).

METHODS

This study ultimately included 2051 patients with TVD and diabetes. Patients were categorized into five groups based on their HbA1c levels: < 6.0 %, 6.0-6.4 %, 6.5-6.9 %, 7.0-7.9 %, and ≥ 8.0 %. The primary endpoint was all-cause death, and the secondary endpoint was major adverse cardiovascular and cerebrovascular events (MACCE).

RESULTS

The median follow-up time was 5.88 years. During this period, a total of 323 (15.7 %) all-cause deaths and 537 (26.2 %) MACCEs were recorded. The relationship between HbA1c and the risk of endpoint events showed a J-shaped pattern, with the lowest risk observed between 6.0 % and 6.4 %. Further analysis revealed a significant interaction between HbA1c and age. In the subgroup with age < 70 years, as HbA1c increased, the risk of endpoint events gradually rose. While in the subgroup with age ≥70 years, there was an L-shaped relationship between HbA1c and endpoint events, with the highest risk observed in patients with HbA1c < 6.0 %.

CONCLUSION

Our study revealed variations in the relationship between HbA1c levels and endpoint events among patients with TVD and diabetes of different ages. In younger patients, elevated HbA1c levels were associated with a higher risk of death and MACCE, while in older patients, excessively low HbA1c levels (HbA1c < 6 %) were linked to a higher risk of death and MACCE.

Clinical and Financial Outcomes of a Pilot Pharmacist-Led Continuous Glucose Monitoring Clinic

Purpose: What are the clinical and financial outcomes of patients using a continuous glucose monitor (CGM) as part of a pilot pharmacist-led service in a Federally Qualified Health Center (FQHC)? Methods: This single-center, prospective cohort conducted in a FQHC from October 2022 to September 2023 was submitted to IRB for review [EXMT-P-22-F-17]. Patients were seen by a pharmacist in collaboration with an attending physician during diabetes specific visits. A total of 15 patients were seen in the pharmacist-led clinic (5 males and 10 females). While follow-up visits were scheduled in-person every 3 months to obtain a hemoglobin A1c (HbA1c), patients could also be seen in the clinic for additional visits. Reimbursement rates were analyzed to determine financial outcomes of the pharmacy service. Results: Pharmacists saw 15 patients for their initial CGM visits, with 8 patients returning for follow-up. The average HbA1c at the first visit was 10% ± 2.49 and decreased at the last follow-up to 8.05% ± 0.29. Time in range (TIR) was obtained for 8 patients through the CGM device or online data monitoring. The average TIR 2 weeks after the first pharmacist visit was 39.625% ± 23.19 and increased to 48.75% ± 11.41 at the completion of the project. A total of 39 visits were conducted, with a total reimbursement rate of $5,978.54. Conclusion: This pharmacist-led pilot CGM clinic showed improvements in clinical outcomes and provided financial reimbursement for diabetes management in addition to typical office visit revenue. Further research should focus on clinical impact of pharmacist-led continuous glucose monitor clinics in larger patient populations, as well as financial sustainability of the service in both physician clinics and FQHC's.

Association of Body Weight Time in Target Range With the Risk of Kidney Outcomes in Patients With Overweight/Obesity and Type 2 Diabetes Mellitus

OBJECTIVE

We assessed the relationship of body weight time in target range (TTR) with composite kidney outcome in people with overweight/obesity and type 2 diabetes mellitus (T2DM).

RESEARCH DESIGN AND METHODS

Included in this study were 3,601 participants with baseline estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m2 from the Look AHEAD (Action for Health in Diabetes) trial. Body weight TTR was defined as the proportion of time during the first 4 years that body weight was within the weight loss target (a weight loss of ≥7% from baseline). The primary outcome was composite kidney outcome, defined as eGFR decline ≥30% from baseline and to a level <60 mL/min/1.73 m2 at follow-up visit, or end-stage kidney disease.

RESULTS

During a median follow-up of 8.0 years, 435 cases of composite kidney outcome were documented. Body weight TTR during the first 4 years was inversely associated with the subsequent risk of composite kidney outcome (per SD increment; adjusted hazard ratio [HR] 0.81; 95% CI 0.70-0.93). Accordingly, the adjusted HRs (95% CI) of composite kidney outcome were 1.00 (reference), 0.73 (0.54-1.00), 0.71 (0.52-0.99), and 0.54 (0.36-0.80) for participants with body weight TTR of 0%, >0% to <29.9%, 29.9% to <69.7%, and 69.7% to <100%, respectively. Similar results were found for a doubling of the urine albumin to creatinine ratio (secondary outcome).

CONCLUSIONS

A higher body weight TTR, with a weight loss target of losing ≥7% of initial weight, was associated with a lower risk of kidney outcomes in participants with overweight/obesity and T2DM.

Key indices of glycaemic variability for application in diabetes clinical practice

Near normal glycaemic control in diabetes consists to target daily glucose fluctuations and quarterly HbA1c oscillations in addition to overall glucose exposure. Consequently, the prerequisite is to define simple, and mathematically undisputable key metrics for the short- and long-term variability in glucose homeostasis. As the standard deviations (SD) of either glucose or HbA1c are dependent on their means, the coefficient of variation (CV = SD/mean) should be applied instead as it that avoids the correlation between the SD and mean values. A CV glucose of 36% is the most appropriate threshold between those with stable versus labile glucose homeostasis. However, when near normal mean glucose concentrations are achieved a lower CV threshold of <27 % is necessary for reducing the risk for hypoglycaemia to a minimal rate. For the long-term variability in glucose homeostasis, a CVHbA1c < 5 % seems to be a relevant recommendation for preventing adverse clinical outcomes.

Diabetes Mellitus in the Elderly Adults in Korea: Based on Data from the Korea National Health and Nutrition Examination Survey 2019 to 2020

BACKGRUOUND

We evaluated the prevalence and management of diabetes mellitus (DM) in elderly Korean patients based on data from the Korea National Health and Nutrition Examination Survey (KNHANES).

METHODS

A total of 3,068 adults aged 65 years and older (19.8% of total population) were analyzed using KNHANES from 2019 to 2020. Prevalence, awareness, treatment, and control rates, and comorbidities were analyzed. Lifestyle behaviors and energy intake were also measured.

RESULTS

The prevalence of DM and prediabetes was 29.6% and 50.5%, respectively. The awareness, treatment and control rates were 76.4%, 73.3%, and 28.3%, respectively. The control rate was 77.0% if A1C <7.5% criteria was used. The mean A1C value of individuals with known DM was 7.1%, and 14.5% of the known DM patients had A1C ≥8.0%. Abdominal obesity, hypertension, and hypercholesterolemia were combined with DM in 63.9%, 71.7%, and 70.7%, respectively, and the rate of integrated management was 36.0% (A1C <7.5% criteria). A total of 40.1% of those with DM walked regularly. The percentage of energy intake from carbohydrates was higher in those with DM than in those without DM (P=0.044), while those of fat (P=0.003) and protein (P=0.025) were lower in those with DM than in those without DM in women.

CONCLUSION

In 2019 to 2020, three of 10 adults aged 65 years and older in Korea had DM, and approximately 70% of them had comorbidities. A strategy for more individualized comprehensive care for the elderly patients with DM is urgently needed.

Association of hemoglobin A1c stability with mortality and diabetes complications in older adults with diabetes

INTRODUCTION

Hemoglobin A1c (A1c) treatment goals in older adults should be individualized to balance risks and benefits. It is unclear if A1c stability over time within unique target ranges also affects adverse outcomes.

RESEARCH DESIGN AND METHODS

We conducted a retrospective observational cohort study from 2004 to 2016 of veterans with diabetes and at least four A1c tests during a 3-year baseline. We generated four distinct categories based on the percentage of time that baseline A1c levels were within patient-specific target ranges: ≥60% time in range (TIR), ≥60% time below range (TBR), ≥60% time above range (TAR), and a mixed group with all times <60%. We assessed associations of these categories with mortality, macrovascular, and microvascular complications.

RESULTS

We studied 397 634 patients (mean age 76.9 years, SD 5.7) with an average of 5.5 years of follow-up. In comparison to ≥60% A1c TIR, mortality was increased with ≥60% TBR, ≥60% TAR, and the mixed group, with HRs of 1.12 (95% CI 1.11 to 1.14), 1.10 (95% CI 1.08 to 1.12), and 1.06 (95% CI 1.04 to 1.07), respectively. Macrovascular complications were increased with ≥60% TBR and ≥60% TAR, with estimates of 1.04 (95% CI 1.01 to 1.06) and 1.06 (95% CI 1.03 to 1.09). Microvascular complications were lower with ≥60% TBR (HR 0.97, 95% CI 0.95 to 1.00) and higher with ≥60% TAR (HR 1.11, 95% CI 1.08 to 1.14). Results were similar with higher TIR thresholds, shorter follow-up, and competing risk of mortality.

CONCLUSIONS

In older adults with diabetes, mortality and macrovascular complications are associated with increased time above and below individualized A1c target ranges. Higher A1c TIR may identify patients with lower risk of adverse outcomes.

Glucagon-Like Peptide 1 Receptor Agonists Have the Potential to Revolutionize the Attainment of Target A1C Levels in Type 2 Diabetes-So Why Is Their Uptake So Low?

A target A1C of <7% is the recommended goal for most people with type 2 diabetes. However, many are not achieving this target with their current treatment. Glucagon-like peptide 1 (GLP-1) receptor agonists are highly efficacious in achieving glycemic control and could aid primary care providers (PCPs) in getting patients to their A1C target. However, despite their potential, use of GLP-1 receptor agonists in the primary care setting is limited. This review provides guidance for PCPs on how to help patients achieve their glycemic target and overcome perceived barriers of GLP-1 receptor agonist use, with the overall goal of improving PCP confidence in prescribing these agents.

Association of hemoglobin A1c time in range with risk for diabetes complications

INTRODUCTION

We assessed the association between hemoglobin A1c time in range (A1c TIR), based on unique patient-level A1c target ranges, with risks of developing microvascular and macrovascular complications in older adults with diabetes.

RESEARCH DESIGN AND METHODS

We used a retrospective observational study design and identified patients with diabetes from the Department of Veterans Affairs (n=397 634). Patients were 65 years and older and enrolled in Medicare during the period 2004-2016. Patients were assigned to individualized A1c target ranges based on estimated life expectancy and the presence or absence of diabetes complications. We computed A1c TIR for patients with at least four A1c tests during a 3-year baseline period. The association between A1c TIR and time to incident microvascular and macrovascular complications was studied in models that included A1c mean and A1c SD.

RESULTS

We identified 74 016 patients to assess for incident microvascular complications and 89 625 patients to assess for macrovascular complications during an average follow-up of 5.5 years. Cox proportional hazards models showed lower A1c TIR was associated with higher risk of microvascular (A1c TIR 0% to <20%; HR=1.04; 95%) and macrovascular complications (A1c TIR 0% to <20%; HR=1.07; 95%). A1c mean was associated with increased risk of microvascular and macrovascular complications but A1c SD was not. The association of A1c TIR with incidence and progression of individual diabetes complications within the microvascular and macrovascular composites showed similar trends.

CONCLUSIONS

Maintaining stability of A1c levels in unique target ranges was associated with lower likelihood of developing microvascular and macrovascular complications in older adults with diabetes.

Cardiovascular effects of intensive lifestyle intervention in adults with overweight/obesity and type 2 diabetes according to body weight time in range

BACKGROUND

We aimed to assess whether the cardiovascular effects of intensive lifestyle intervention (ILI) vary for those who can maintain the lower body weight after weight loss through ILI.

METHODS

In the secondary analysis of the Look AHEAD trial, we identified the status of weight loss for the participants in the ILI arm based on body weight time in range (TIR). These participants were allocated to three groups according to body weight TIR: 0% (n = 727), >0% to 50% (n = 656), and >50% to 100% (n = 811). For each group, cardiovascular outcomes were compared with matched participants receiving diabetes support & education (DSE) using 1:1 propensity score matching and Cox regression.

FINDINGS

During a median of 9·5 years of follow-up, participants with TIR of >50% to 100% can effectively maintain their body weight after weight loss through ILI; participants with TIR of 0% or >0% to 50% do not achieve or maintain weight loss. Compared with the corresponding matched participants in the DSE arm, participants with TIR of >50% to 100% in the ILI arm had a 45% lower risk of the primary outcome (HR 0·55, 95% CI 0·40-0·76), and no significant effects were found on the risk of the primary outcome in participants with TIR of 0% (HR 1·12, 95% CI 0·86-1·46) or >0% to 50% (HR 1·14, 95% CI 0·85-1·52).

INTERPRETATION

In adults with overweight/obesity and type 2 diabetes, ILI might help in lowering the risk of cardiovascular events when the lower body weight is maintained after weight loss.

FUNDING

None.

The Association Between Sustained HbA1c Control and Long-Term Complications Among Individuals with Type 2 Diabetes: A Retrospective Study

INTRODUCTION

The prevalence of type 2 diabetes (T2D) represents a rising burden in the US and worldwide, with the condition shown to be associated with relatively large human and economic costs. Part of the reason for such high costs associated with T2D is that the condition is often accompanied by additional health-related complications. The goal of this research is to examine the association between glycemic control and diabetes-related complications for individuals with T2D.

METHODS

The Optum Clinformatics® Data Mart (CDM) database from 2007 to 2020 was used to identify adults with T2D. Individuals were classified as having sustained glycemic control (all hemoglobin A1c [HbA1c] < 7%) or poor glycemic control (all HbA1c ≥ 7%) over the 5-year post-period, and diabetes-related complications were identified based upon the Diabetes Complications Severity Index. Multivariable analyses examined the association between sustained glycemic control and diagnosis of a diabetes-related complication in the post-period.

RESULTS

Maintaining HbA1c < 7% over the 5-year post-period, compared to maintaining HbA1c ≥ 7%, was associated with reduced odds of the diabetes-related complications of cardiovascular disease (odds ratio [OR] = 0.76, 95% confidence interval [CI] 0.61-0.94), metabolic disease (OR = 0.37, 95% CI 0.22-0.600), neuropathy (OR = 0.62, 95% CI 0.45-0.84), nephropathy (OR = 0.81, 95% CI 0.69-0.94), and peripheral vascular disease (OR = 0.52, 95% CI 0.33-0.83). There was no statistically significant association between sustained glycemic control and cerebrovascular disease.

CONCLUSIONS

Sustained glycemic control was found to be associated with significant reductions in the odds of being diagnosed with diabetes-related complications over a 5-year post-period.