HbA1c is the test recommended to be used in the diagnosis of Type 2 Diabetes by the American Diabetes Association and the World Health Organization, which provides information about the long-term glucose level. It stands for Glycosed Hemoglobin.
HbA1C is formed by the binding of glucose and red blood cells. The HbA1C test is also called Glycosed Hemoglobin.
Red blood cell life span is estimated to be around 117 days in men and 106 days in women. Red Blood Cells are exposed to glucose in the blood. The higher the blood sugar, the higher the HbA1C. The HbA1C value is the value that shows the average blood glucose level of people for a period of 2-3 au(1).
In normal individuals, the average HbA1C value is around 5%. However, HbA1C is not always 100% related to blood glucose. It may change as a result of some external factors.
For example, if your Red Blood Cells live longer than normal or if the size of your red blood cells, which we call MCV, is smaller than normal, your HbA1C value may be high.
What is the normal HbA1C value range?
HbA1C value is expected between 4% and 5.6% in healthy individuals. These values may vary by 0.2 points with the laboratory’s own reference values.
People with an HbA1C value between 5.7% and .4% are in the high risk group for diabetes.
If the value is above 6.5%, we can say that the person has diabetes. However, HbA1C value alone may not be sufficient to diagnose diabetes. In some studies, it has been shown that HbA1C and 2-hour postprandial glucose values are different from each other.
It is recommended that patients diagnosed with diabetes have HbA1C tests at least twice a year.
What are the Advantages of Hba1c Test over Other Tests?
It does not require hunger, it is a test that can be done anytime.
It is not affected by situations that may occur before the test such as physical activity and stress
It is not affected by short-term hormone levels
It can be done quickly, it is a time-saving test.
HbA1C is more stable at 37 degrees than glucose.
Hba1c Value Variations
By Time:
HbA1C varies with time. In the studies, HbA1C tests performed in the summer months gave higher results than those performed in the winter months. This difference is around 0.3%. This difference may change due to reasons such as exercise, sun exposure time, and decreased carbohydrate intake.
By Race:
HbA1C values were found to be between 0.27 and 0.4% higher in African and South Asian people compared to European people.
It was stated that the HbA1C level of Black Africans reached less than 7% more easily, and in addition, eye, kidney, and cardiovascular problems were less common.
By Gender:
Metabolic Problems were observed to be higher in people with higher HbA1C in men than in women.
Age:
HbA1C increases with age, independent of diabetes.
The HbA1C value is 0.47% higher in patients over 70 years of age than in patients younger than 30 years of age.
According to the studies conducted on the increase in HbA1C with age, an increase of 0.074% – 0.094% is observed every 10 years.
This value increases more in patients with family history and diabetes.
HbA1C Increases in Diabetes Patients:
We mentioned that HbA1C being above 6.5% is a very important indicator for diabetes.
In a study conducted in Japan, it was determined that the higher the HbA1C value in subjects between the ages of 30-79, the higher the risk of diabetes.
It has been determined that people are at risk of diabetes in the future when the HbA1C value is above 5.7%.
In 2015, the American Diabetes Association stated that patients with an HbA1C value between 5.7% and 6.4% were in the pre-diabetes risk group and the risk of diabetes in the future was very high. It was also determined that 9.3% of the population in America was diabetic.
Diabetes Complications Increase with High Hba1c Value:
In the study, increased HbA1C value in type 1 diabetes patients causes an increase in kidney and eye problems. This problem is not seen below the value of 7.6%.
Of course, this is not only dependent on the HbA1C value. In addition, many other problems cause results to vary.
In addition, non-healing wounds occur in the extremities such as hands and feet in individuals with increased HbA1C and cause cuts.
Compared to patients with an HbA1C value of less than 8, pain increased 2 times in people with an HbA1C value of 8 or more.
HBA1C Value Increases in Kidney Diseases:
The risk of chronic kidney disease increases in people with high HbA1C values.
Of course, there are other parameters in addition to the HbA1C value.
However, increased HbA1C value may be affected by blood urea. Values may vary in patients with chronic kidney disease.
Diabetes and Hearing Defects:
It has been proven by many studies that high HbA1C value causes an increase in hearing defects in people who do not have diabetes.
High Hba1c Value Causes Increase in Cognitive (Intellectual) Problems:
It has been understood that high HbA1C value causes intellectual disorders in healthy adults. In addition, these people have been noticed in attacks of forgetfulness. This condition is more common in women.
Learning and memory problems are seen in people with an HbA1C value above 8.8 in childhood.
High Hba1c Value Increases Alzheimer’s and Dementia Risk:
High HbA1C value causes an increase in Alzheimer’s and dementia risk.
High Hba1c Value is Associated with the Increase in Dental and Gum Diseases:
Oral hygiene is associated with blood glucose levels. It has been determined that the HbA1C value is high in people with gingival problems in diabetes controls.
Blood Iron Value And Anemia Affects Hba1c Values:
The level of blood iron value is affected by the HbA1C value, especially in deeply anemic individuals. Many forms of anemia have been proven to be associated with low HbA1C.
Similarly, it is noteworthy that the HbA1C value is high in anemic individuals and those with low B12 levels.
In addition, it was observed that anemia patients improved as HbA1C normalized.
Hba1c Value Is Associated with Fatigue:
Permanent fatigue occurs in 45% of type 1 diabetes patients. Studies have shown that the higher the HbA1C value, the greater the fatigue.
On the other hand, in patients with type 2 diabetes, significant fatigue is observed in patients with an HbA1C value of more than 7%.
High HbA1C Value Increases Anxiety and Depression:
Diabetics often have an increased risk of depressive mode, sleep problems, appetite disorders, and suicide. This increase was shown at the same rate as the increase in HbA1C value. This situation is also more common in Type 1 patients than in Type 2 patients.
The risk of suicide increases significantly in people with an HbA1C value above 6.5%.
In a study conducted in Africa, the risk of depression and anxiety increased in individuals with an HbA1C value above 9.
Relationship between High HbA1C and Hyperactivity:
Hyperactivity is seen more frequently in children with high HbA1C value than in children with normal blood glucose value.
The Relationship between High HbA1C and Atherosclerosis:
Atherosclerosis is more common in type 1 adolescent patients with high HbA1C values.
Vascular occlusion is associated with HbA1C value and blood sugar value.
Elevated HbA1C causes more atherosclerosis in diabetic patients than in individuals without diabetes.
Relationship between elevated HbA1C and heart diseases:
Heart disease-related deaths have increased in both diabetic and nondiabetic patients with elevated HbA1C.
Each 1% increase in HbA1C value increases the death rate due to Cardiovascular Diseases up to 35%. In patients without diabetes, this risk is around 26%.
An increase in HbA1C value causes an increase in LDL (Male Cholesterol), blood cholesterol and triglyceride values at the same rate.
In addition, chronically increased glucose value causes a decrease in heart functions at the same rate.
Helicobacter Pylori Infection May increase HbA1C value:
The relationship of chronic HbA1C elevation in elderly people with helicobacter pylori infection has been proven. In addition, H. Pylori treatment causes a decrease in HbA1C value in people with insulin resistance. In the light of these two studies, it is understood that H.Pylori infection affects the HbA1C value.
High HbA1C May Be Related to Digestive System Anomalies:
Digestive system anomalies, especially Colorectal Anematous Polyps, have been seen in people with high HbA1C values. This effect is particularly evident over the age of 50.
High HbA1C Relationship with Fatty Liver:
It has been proven by studies that both obesity and fatty liver increase with increasing HbA1C value in people who do not have diabetes.
Especially in patients with HbA1C value above 6.5%, fatty liver shows significant increases.
High HbA1C Impairs Immune Response:
Studies have shown that individuals who have influenza vaccine and whose HbA1C value is above 7.6% show lower immunity to the virus.
High Hba1c Value Causes Sleep Disorders:
Both sleep disorder problems in which long and short-term sleep occur are associated with increased HbA1C value.
In addition, the increase in HbA1C value also causes deterioration in sleep quality.
Sleep apnea is more common in Type 1 diabetes patients with high HbA1C values.
The Relationship Between Irregular Menstrual Cycle and Hba1c Value:
There are some changes in the menstrual cycle in women with type 1 diabetes. In particular, for every 1 point HbA1C increase, the menstrual period is prolonged by 3 days.
The relationship between high HbA1C value and Bone loss:
Another complication found in diabetes patients is osteoporosis.
Osteocalcin is a protein produced in bone cells. It is involved in bone density and bone formation. In a study conducted with type 1 diabetes patients, it was reported that patients with high HbA1C values had low osteocalcin values.
In addition, women with high HbA1C value have a higher rate of cheesic dissolution.
High Hba1c Association with Metabolic Syndrome:
Many studies have proven that high HbA1C levels are associated with metabolic syndrome in people without diabetes.
High HbA1C Relationship with Obesity:
The relationship between obesity and insulin resistance is known. It has been proven that high body mass index, increase in waist and hip width are associated with increased HbA1C value.
High HbA1C value Relation to Cancer:
Cancer patients with high HbA1C values have a higher death rate than cancer patients with low HbA1C values.
Increased HbA1C value has been proven to be associated with an increase in colorectal, pancreatic, respiratory tract, and female genital cancers.
In addition, 5-year survival rate is lower in patients with HbA1C value above 7.5% compared to normal individuals.
HbA1C and Pregnancy:
In addition to this information, it is obvious that pregnant women with high HbA1C values pose a higher risk for gestational diabetes.
In addition, the risk of preeclampsia is more common in individuals with an HbA1C value greater than 5.9%.
In addition, in a study, the rate of congenital baby anomaly was 27.8% in those with a diabetic level of HbA1C, while it was 9.8% in those with prediabetic and 3% in those with normal.
HbA1C is an important test in the diagnosis of diabetes and in predicting many risk factors that may develop.
