Blutwerte · Marker

HbA1c

Glykiertes Hämoglobin · Glycated Hemoglobin · A1c · Langzeitzucker

Stoffwechsel & Glukose

Einheit:: %

HbA1c quantifies the percentage of hemoglobin molecules in the blood that are glycated, reflecting average blood glucose levels over two to three months.

Reference Ranges

Reference

4–5.6%

4.5

5.4

5.6

LowNormalHigh

Reference

Optimal

Unit · %

Reference ranges may vary slightly by laboratory and population.

Overview

Übersicht

Hemoglobin A1c (HbA1c) is a form of hemoglobin that is chemically linked to a sugar. It is used as a biomarker to measure the average plasma glucose concentration over prolonged periods, typically reflecting the glycemic history of the preceding two to three months. Researchers have found that HbA1c is a critical indicator for diagnosing and managing diabetes, as it provides a reliable measure of chronic hyperglycemia and correlates with the risk of long-term diabetes complications, such as coronary heart disease and stroke. In the context of athletic performance and biohacking, maintaining optimal HbA1c levels can be crucial for metabolic health and longevity, as it reflects efficient glucose metabolism and reduced risk of metabolic disorders. However, several factors can confound HbA1c measurements, including conditions that affect red blood cell turnover, such as anemia, chronic kidney disease, and recent blood transfusions. These factors may lead to inaccurate readings, necessitating careful interpretation of results.

Klinische Bedeutung
Elevated HbA1c levels indicate poor long-term glycemic control and increased risk of diabetes complications. Lower values suggest better glucose management but may also indicate conditions like anemia or recent blood loss.

Dynamics

Trend Interpretation

Rising Values

Progressively rising HbA1c values suggest worsening glycemic control, necessitating review of diabetes management strategies. Retest in 3 months if elevated.

Falling Values

Falling HbA1c values indicate improved glycemic control, but sudden drops may require investigation for underlying conditions like anemia.

Re-test Interval

3 months if outside optimal range

Etiology

Causes — High & Low

Cause

Elevated Levels

Poor glycemic control
Diabetes mellitus
Chronic kidney disease
Iron deficiency anemia
Splenectomy

Cause

Low Levels

Hemolytic anemia
Recent blood transfusion
Chronic liver disease
Vitamin B12 deficiency
Acute blood loss

Protocol

How to Optimize

Lever

Lifestyle

Regular physical activity
Weight management
Stress reduction

Lever

Nutrition

Low glycemic index foods
High fiber diet
Balanced macronutrient intake

Lever

Supplementation

Chromium
Berberine

Note:

Consult a healthcare provider before starting any supplementation, especially if managing diabetes or other chronic conditions.

Testing Guidelines

✓Fasting Not Required

✓Not Time-Sensitive

Testing Frequency

Every 3-6 months for individuals with diabetes or at risk.

Interfering Factors

Recent blood transfusion
Hemoglobinopathies
Chronic kidney disease

Related Peptides & Hormones

C Peptide

Correlated with

hormone or peptide

Open Research Questions

Current research suggests that the interpretation of HbA1c levels in populations with advanced chronic kidney disease and thalassemia remains debated due to confounding factors affecting red blood cell lifespan and glycemic control. Researchers have not yet established optimal HbA1c targets for these groups, nor have they fully validated alternative biomarkers like glycated albumin. Unanswered clinical questions include the precise impact of HbA1c variability on long-term complications in diverse patient populations.

45 Research Publications

2,650

Total Citations

Human/RCT

10.0

Avg. Influence

2024

Latest

Sort

Filter

01Top

#01

Significance of HbA1c Test in Diagnosis and Prognosis of Diabetic Patients.

ReviewInfluence74.0

1211

This review examined the significance of HbA1c as a biomarker for diagnosing and predicting outcomes in diabetes patients. Researchers found that elevated HbA1c levels correlate with long-term complications, including coronary heart disease and stroke, making it a reliable indicator of chronic hyperglycemia.

View on PubMed

02Top

#02

CLINICAL PRACTICE. Polycystic Ovary Syndrome.

Case ReportInfluence17.0

399

This study examined a 22-year-old woman with polycystic ovary syndrome (PCOS) who presented with symptoms such as hirsutism and irregular menses. Researchers found that her glycated hemoglobin (HbA1c) level was 5.7%, indicating a slightly elevated level compared to normal values. This case highlights the importance of evaluating and managing symptoms associated with PCOS.

View on PubMed

03Top

#03

Glycemic Monitoring and Management in Advanced Chronic Kidney Disease.

ReviewInfluence12.0

183

This study explored the challenges of using HbA1c for glycemic monitoring in patients with advanced chronic kidney disease (CKD). Researchers found that while HbA1c remains the preferred biomarker, its accuracy can be compromised by CKD-related factors, suggesting a target range of 7% to 8% for optimal management.

View on PubMed

#04

Novel biomarkers for prediabetes, diabetes, and associated complications.

ReviewInfluence12.0

170

This review discussed the limitations of current biomarkers for diagnosing prediabetes and diabetes. Researchers found that combining multiple biomarkers may improve the identification of individuals at high risk for developing diabetes, addressing the growing epidemic of dysglycemic disorders.

View on PubMed

#05

HbA1c and factors other than diabetes mellitus affecting it.

ReviewInfluence5.0

121

This article reviewed the factors influencing HbA1c levels beyond blood sugar. Researchers found that various physiological factors can affect HbA1c, emphasizing the importance of understanding these influences for accurate clinical interpretation.

View on PubMed

#06

Potential Biomarkers for Post-Stroke Cognitive Impairment: A Systematic Review and Meta-Analysis.

Meta-AnalysisInfluence6.0

121

This systematic review and meta-analysis evaluated blood biomarkers for post-stroke cognitive impairment (PSCI). Researchers found that while HbA1c levels did not differ significantly between PSCI and non-PSCI groups, other biomarkers like homocysteine and C-reactive protein showed potential as indicators.

View on PubMed

#07

Is There a Role for HbA1c in Pregnancy?

ReviewInfluence5.0

108

This study examined the role of HbA1c testing during pregnancy. Researchers found that while HbA1c can indicate underlying hyperglycemia, its utility in diagnosing gestational diabetes is limited compared to oral glucose tolerance tests. The study suggests that HbA1c may be more useful postpartum when combined with other assessments.

View on PubMed

#08

Glycated Hemoglobin (HbA1c) as a Biomarker for Diabetic Foot Peripheral Neuropathy.

ReviewInfluence1.0

This systematic review investigated the role of HbA1c in predicting diabetic foot peripheral neuropathy. Researchers found that HbA1c levels are associated with complications related to diabetic foot, but emphasized the need for more research in this area. The study suggests that HbA1c could be a useful biomarker for early diagnosis and management.

View on PubMed

#09

Laboratory Parameters of Hemostasis, Adhesion Molecules, and Inflammation in Type 2 Diabetes Mellitus: Correlation with Glycemic Control.

HumanInfluence2.0

This study examined the relationship between glycemic control and various hemostatic and inflammatory markers in type 2 diabetes mellitus (T2DM) patients. Researchers found that poor glycemic control, indicated by higher HbA1c levels, correlated with increased inflammatory markers and prothrombotic states.

View on PubMed

#10

Glycated Hemoglobin (HbA1c): Clinical Applications of a Mathematical Concept.

UnknownInfluence1.0

This study presented a mathematical model to understand HbA1c as a reflection of glucose exposure over time. Researchers found that this model could help patients and clinicians better interpret HbA1c levels in relation to blood glucose monitoring.

2018

Primary outcome

Change in HbA1c

Type1diabetesType1 Diabetes MellitusGlucose Metabolism Disorders

Study to Assess the Effects and Safety of ZGN-1061 in Overweight and Obese Participants With Type 2 Diabetes

NCT03254368Phase 2COMPLETED

Sponsor

Zafgen, Inc.

Enrollment

188

Started

2017

Primary outcome

Change in HbA1c

Type 2 Diabetes MellitusOverweight and Obesity

Research Study Comparing a New Medicine Semaglutide to Liraglutide in People With Type 2 Diabetes

NCT03191396Phase 3COMPLETED

Sponsor

Novo Nordisk A/S

Enrollment

577

Started

2017

Primary outcome

Change in HbA1c

DiabetesDiabetes Mellitus, Type 2

TriMaster: Study of a DPP4 Inhibitor, SGLT2 Inhibitor and Thiazolidinedione as Third Line Therapy in Patients With Type 2 Diabetes.

NCT02653209Phase 4COMPLETED

Sponsor

Royal Devon and Exeter NHS Foundation Trust

Enrollment

525

Started

2016

Primary outcome

On treatment HbA1c in obese patients (BMI >30kgm-2), compared to non-obese patients

Type 2 Diabetes

Integrative Care for Type 2 Diabetes

NCT02843724Phase 1/2UNKNOWN

Sponsor

The Canadian College of Naturopathic Medicine

Enrollment

148

Started

2016

Primary outcome

Clinically meaningful reduction of HbA1c above and beyond that of control arm

Diabetes Mellitus, Type 2

Trial to Incentivise Adherence for Diabetes

NCT02224417COMPLETED

Sponsor

Duke-NUS Graduate Medical School

Enrollment

240

Started

2015

Primary outcome

HbA1c levels

Type 2 Diabetes Mellitus

Efficacy and Safety of Ertugliflozin (MK-8835/PF-04971729) With Sitagliptin in the Treatment of Participants With Type 2 Diabetes Mellitus (T2DM) With Inadequate Glycemic Control on Diet and Exercise (MK-8835-017)

NCT02226003Phase 3COMPLETED

Sponsor

Merck Sharp & Dohme LLC

Enrollment

291

Started

2014

Primary outcome

Change From Baseline in Hemoglobin A1C (HbA1C) at Week 26 - Full Analysis Set (FAS Population Excluding Rescue Approach

Type 2 Diabetes Mellitus

The Link Between "Time In Range" Versus HbA1c and the Presence of Chronic COmplications in Type 1 Diabetes: a Longitudinal Study

NCT05530369COMPLETED

Sponsor

University Hospital, Antwerp

Enrollment

479

Started

2014

Primary outcome

Time In Range (TIR, 70-180 mg/dL)

Diabetes Mellitus, Type 1

Ertugliflozin and Sitagliptin Co-administration Factorial Study (VERTIS FACTORAL, MK-8835-005)

NCT02099110Phase 3COMPLETED

Sponsor

Merck Sharp & Dohme LLC

Enrollment

1,233

Started

2014

Primary outcome

Change From Baseline in A1C at Week 26: Excluding Rescue Approach

Type 2 Diabetes Mellitus

Safety and Efficacy of Ertugliflozin in the Treatment of Participants With Type 2 Diabetes Mellitus Who Have Inadequate Glycemic Control on Metformin and Sitagliptin (MK-8835-006; VERTIS SITA2)

NCT02036515Phase 3COMPLETED

Sponsor

Merck Sharp & Dohme LLC

Enrollment

464

Started

2014

Primary outcome

Change From Baseline in Hemoglobin A1C at Week 26

Type 2 Diabetes Mellitus

A Study To Evaluate The Efficacy And Safety Of Ertugliflozin In Participants With Type 2 Diabetes Mellitus And Inadequate Glycemic Control On Metformin Monotherapy (MK-8835-007).

NCT02033889Phase 3COMPLETED

Sponsor

Merck Sharp & Dohme LLC

Enrollment

621

Started

2013

Primary outcome

Change From Baseline in A1C at Week 26 (Excluding Rescue Approach)

Type 2 Diabetes Mellitus

A Study of the Safety and Efficacy of Glimepiride, Gliclazide, Repaglinide or Acarbose When Added to Sitagliptin + Metformin Combination Therapy in Chinese Participants With Diabetes (MK-0431-313)

NCT01709305Phase 4COMPLETED

Sponsor

Merck Sharp & Dohme LLC

Enrollment

5,570

Started

2012

Primary outcome

Change From Phase 2 Baseline to Week 44 in Hemoglobin A1c (HbA1c) Levels (Phase 2)

Type 2 Diabetes Mellitus

Behavioral Activation Therapy for Rural Veterans With Diabetes and Depression

NCT01572389COMPLETED

Sponsor

VA Office of Research and Development

Enrollment

225

Started

2012

Primary outcome

Change in Hemoglobin A1C

Diabetes MellitusDepression

A Study of the Safety and Efficacy of Omarigliptin (MK-3102) Compared With Glimepiride in Participants With Type 2 Diabetes Mellitus With Inadequate Glycemic Control on Metformin (MK-3102-016)

NCT01682759Phase 3COMPLETED

Sponsor

Merck Sharp & Dohme LLC

Enrollment

751

Started

2012

Primary outcome

Change From Baseline in Hemoglobin A1C at Week 54

Type 2 Diabetes Mellitus

A Study of the Effect of Ezetimibe on Glucose Metabolism in Type 2 Diabetics With Hypercholesterolemia (P06541)

NCT01611883Phase 4COMPLETED

Sponsor

Organon and Co

Enrollment

152

Started

2012

Primary outcome

Change in Glycated Hemoglobin (HbA1c) From Baseline

Hypercholesterolemia

A Study in Participants With Type 1 Diabetes Mellitus

NCT01481779Phase 3COMPLETED

Sponsor

Eli Lilly and Company

Enrollment

455

Started

2012

Primary outcome

Hemoglobin A1c (HbA1c) at 26 Weeks

Diabetes Mellitus, Type 1

NCT01024244Phase 2TERMINATED

Sponsor

Eli Lilly and Company

Enrollment

Started

2009

Primary outcome

Change From Baseline in Glycosylated Hemoglobin A1c (HbA1c) at 12 Weeks

Diabetes Mellitus, Type 2

Improving Function, Quality of Life, Glycemia in Diabetics With Dementia

NCT00792662Phase 4WITHDRAWN

Sponsor

University of Nebraska

Enrollment

Started

2008

Primary outcome

Hemoglobin A1C as a Marker for Glycemic Control

Diabetes MellitusAlzheimer's DiseaseApathyDementia

Study In People With Type 2 Diabetes

NCT00196989Phase 2COMPLETED

Sponsor

GlaxoSmithKline

Enrollment

448

Started

2005

Primary outcome

Percentage change from Baseline (Day 1) in glycated hemoglobin (HbA1c) levels at Week 16 as a measure of improvement in glucose control

Diabetes Mellitus, Type 2

Publication Trend

Research publications about HbA1c over time

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