What’s Behind Racial and Ethnic Disparities in Diagnosing Type 2 Diabetes?

Diabetes is a chronic disease that causes high blood sugar levels, and type 2 is the most common form. In type 2 diabetes, the body doesn’t respond to insulin.¹ This hormone controls blood sugar levels by allowing glucose to move into cells. Due to insulin resistance, people with type 2 diabetes have high blood sugar and insulin levels. 

Diabetes can lead to serious complications, including kidney diseases, blindness, cardiovascular disease, and fatty liver disease.² Therefore, early diagnosis and treatment are important because these complications can reduce prognosis and quality of life.³

Type 2 diabetes (T2D) is more common in minority racial and ethnic groups.⁴ Socioeconomic and environmental factors may play a role in creating racial and ethnic disparities. These include education, housing, income, environmental exposures, and genetic predisposition.⁵

Prevalence of T2D among different racial and ethnic groups

Diabetes affects more than 37 million people in the United States, including 28.7 million diagnosed and 8.5 million undiagnosed people.⁶ Approximately 90% of the cases correspond to type 2 diabetes.⁷ Around 1.4 million people are diagnosed each year.⁸

Type 2 diabetes is becoming more common. Research suggests that the number of US adults diagnosed with diabetes will triple by 2060.⁹ Rates of diabetes are also increasing in youth. If the current trend continues, we will see a 673% increase in people under the age of 20 by then.¹⁰

However, this disease doesn’t affect everyone equally. Diabetes disproportionately affects Black, Indigenous, and other people of color in the United States.¹¹

The current rates of diagnosed diabetes are: 

• 12.7% of Black people 

• 11.3% of Asian people

• 11.1% of Hispanic people

• 11% of white people

• 23.5% of American Indian/Alaskan Native people¹²

• 19.8% of Native Hawaiian or other Pacific Islander¹³

Diabetes is currently the eighth leading cause of death in the US.¹⁴ The death rates of diabetics are higher in minority races. Black people are twice as likely, Hispanic people 1.3 times more likely, and Native Americans/Alaskan Natives almost twice as likely to die from diabetes than white people.¹⁵ ¹⁶

Differences in hospital admissions are also pronounced. Black people are 2.5 times more likely to be hospitalized for uncontrolled diabetes with complications than white people.¹⁷

People from ethnic minority groups are more likely to develop diabetic ketoacidosis, cardiovascular complications, and end-stage kidney disease. They are also more likely to suffer strokes and require amputations.¹⁸

What are the most common symptoms of T2D?

Common symptoms of type 2 diabetes include:¹⁹

• Increased urination

• Persistent thirst

• Hunger, despite eating often

• Extreme fatigue

• Blurred vision

• Slow healing of cuts or bruises

• Tingling, pain, or numbness in the hands and feet

• Frequent infections in the genital areas, urinary tract, skin, and mouth²⁰

• Erectile dysfunction

• Dry mouth 

Some people in the early stages of diabetes have very minor or no symptoms, so early screening is not always accurate.²¹

How is type 2 diabetes diagnosed?

Type 2 diabetes diagnosis is based on plasma glucose levels. Doctors can measure plasma glucose in a few ways, including:²²

Fasting plasma glucose

A blood test is taken after fasting for at least eight hours. Plasma glucose levels greater than 126 mg/dL (7.0 mmol/L) indicate diabetes. 

Two-hour plasma glucose tolerance test

Blood tests are taken before and after consuming a glucose solution. Plasma glucose levels greater than 200 mg/dL (11.1 mg/dL) indicate diabetes. 

HbA1C

This blood test measures HbA1c, the amount of glucose linked to hemoglobin, an oxygen-carrying protein. HbA1c levels greater than 6.5% (48 mmol/L) indicate diabetes. 

As hemoglobin regularly remains in the body for ~120 days, HbA1c levels indicate high blood sugar levels for long periods. Consequently, HbA1c is a longer-term measure than the other two tests. 

In a patient with classic symptoms of hyperglycemia or a hyperglycemia crisis, a random plasma glucose test with levels above 200 mg/dL (11.1 mmol/L) can also diagnose diabetes. 

In the absence of unequivocal hyperglycemia, a diabetes diagnosis requires either two abnormal tests from the same sample or two separate test samples.²³

Nonnmodifiable type 2 diabetes risk factors

You can’t manage some risk factors for type 2 diabetes, including:²⁴

Age

The risk of type 2 diabetes increases with age. It is most common after age 35, but children and teens are more frequently developing the disease. 

Genetics and family history

Genetic variants can make people more susceptible to type 2 diabetes. Some variants affect the insulin-secreting beta cells in the pancreas or impact insulin action in another way.²⁵

If you have a family member with a history of diabetes, you may have a genetic predisposition. People with a family history of diabetes are more likely to develop the disease themselves.

Having gestational diabetes

Women who have had gestational diabetes, the type that occurs during pregnancy, are more likely to develop type 2 diabetes. Babies born to a mother with gestational diabetes are also at an increased risk. 

Race

Those who are Black, Native American, Asian American, Hispanic, or Pacific Islander are more likely to develop diabetes. 

Birth weight

Babies born with a low birth weight are at increased risk of developing type 2 diabetes later in life. 

Potentially manageable risk factors of T2D

Some people can manage certain diabetes risk factors, including: 

Weight

Excess weight or increased body fat in the abdominal region increases the risk of diabetes.²⁶

Low physical activity

Exercising less than three times per week increases the risk of diabetes.²⁷

Diet

A diet high in red and processed meat, sugary drinks, and refined grains increases the risk of diabetes.²⁸ Socioeconomic factors are often barriers to obtaining and consuming nutritious food.²⁹

Smoking

People who smoke and have exposure to second- and third-hand smoke are more likely to develop diabetes.³⁰ There’s also a small risk for former smokers. 

Exposure to pollutants

Organic pollutants can accumulate in adipose tissue (fat), increasing the risk of type 2 diabetes.³¹

How do education, environment, and access to healthcare play a role?

Social determinants of health are the non-medical factors that impact health and quality of life. These influence type 2 diabetes occurrence, diagnosis, and treatment. 

Examples of social determinants include: 

• Economic stability

• Education

• Access to healthcare

• Neighborhood

• Social community

For example, in developed countries, people with low socioeconomic status are more likely to get diabetes, with links to low education.³² The region where someone lives is also a factor. 

Researchers have found that environmental and genetic factors interact in causing type 2 diabetes.³³

Still, we need more research to fully understand how fixed genetic and environmental factors related to the social determinants of health contribute to diabetes development. 

Racial disparity in diabetes diagnosis: understanding the root

One study found that around 650,000 Black people in the US have a genetic variant that reduces the accuracy of the HbA1c blood test.³⁴ This suggests diabetes screening may not always be effective for Black people.

However, larger structural barriers negatively affect Black people and other minority populations, which research has explored. 

Barriers to accessing diabetes screening and diagnostic services

Minority racial groups experience barriers to diabetes screening and diagnostic services. More than 80% of people from minority groups don’t know they have prediabetes.³⁵

Minority populations are less likely to receive preventative care, HbA1c testing, and screening for diabetes complications, such as cholesterol testing and retina examinations.³⁶ One study found less than half of Asian Americans who met the criteria for testing actually received it.³⁷

Racial disparities in medical care exist. Structural racism continues to affect the access and quality of care provided to people from minority races, among other socioeconomic and environmental factors. 

The following factors are barriers to diabetes screening and diagnostic services:

Lack of healthcare coverage and insurance

Insurance is important for people with diabetes because it reduces the cost burden and improves access to care.³⁸

Uninsured people are more likely to experience challenges accessing crucial routine and preventative care relating to diabetes complications and disease progression.³⁹

The Affordable Care Act intervention has increased insurance coverage for people who otherwise couldn’t access it. 

Despite these improvements, people from racial minority groups are still more likely to be uninsured and lack a usual source of healthcare compared to white people.⁴⁰ Additionally, some states have not expanded their Medicaid program.⁴¹

Geographical disparities

Researchers have described a “diabetes belt” in the United States: Diabetes rates are heavily concentrated in 644 counties among 15 states, most of which are southern.⁴²

Black people are more likely to live in states inside the “diabetes belt.” Researchers believe access to care and lack of health insurance coverage in these areas are the main reasons for health disparities in this region.⁴³

Lack of culturally sensitive care

A study found that women with gestational diabetes experienced challenges surrounding screening for type 2 diabetes.⁴⁴ This was due to cultural differences and language barriers between them and their healthcare providers. 

Cultural sensitivity and awareness are important. Healthcare professionals may not understand the cultural significance behind a minority population’s diet and staple cultural foods, like rice and bread.⁴⁵

People who have not had diabetes screening are more likely to note these negative experiences. 

Stigma and distrust in the healthcare system

People with diabetes often experience stigma relating to their condition.⁴⁶ Negative attitudes and fear of judgment, discrimination, or prejudice can affect how someone manages their diabetes. 

In addition, Black and Hispanic people are more likely to report a lack of trust in healthcare professionals.⁴⁷ Plus, some healthcare professionals show bias in favor of white patients.⁴⁸

Long-lasting discrimination in the healthcare system also contributes to racial inequities surrounding healthcare use, treatment, and care. Historical unethical medical experiments have also contributed to distrust in the healthcare system today.  

How to reduce disparity in T2D screening and diagnosis

Enhancing access to screening services is an important way to improve disparities in obtaining a type 2 diabetes diagnosis. 

One way to improve access to screening services is to ensure federal and national programs are available for high-risk minority groups by making them free or subsidized. 

This could include expanding insurance coverage for prediabetes and type 2 diabetes screening and diagnostic testing, as Medicaid may not cover this for prediabetes.⁴⁹

Screening for G6PD variant

The HbA1c test can be inadequate for diagnosing type 2 diabetes in some Black people due to the unique genetic variant that reduces HbA1c blood levels.⁵⁰

Specifically, GP6D shortens the life cycle of red blood cells. This means the test can underestimate the amount of hemoglobin bound to glucose. 

Because of this, screening for the glucose-6-phosphate dehydrogenase (G6PD) genetic variant alongside HbA1c may be best.⁵¹ Alternatively, doctors could use other diagnostic tests like fasting glucose levels.

Screening for prediabetes

Screening can lead to earlier detection, diagnosis, and treatment of type 2 diabetes.⁵² This can reduce the disease progression and prevent complications, such as kidney or cardiovascular disease. 

Current screening recommendations

The American Diabetes Association (ADA) recommends screening the following groups for diabetes:⁵³

• Adults who are overweight (BMI of at least 25 kg/m2 and 23 kg/m2 in Asian Americans) and have at least one other diabetes risk factor. 

• General screening should begin at age 45. 

• People with prediabetes should be tested yearly.

• People with a history of gestational diabetes should be tested every three years. 

• Children who are overweight (above the 85th percentile) should be tested if they: 

• Have a mother with diabetes or who had gestational diabetes 

• Have a family history in a first or second-degree relative

• Show signs of insulin resistance

• Belong to a minority group 

Culturally competent care

Healthcare providers need to develop culturally appropriate approaches to healthcare to reduce the burden of type 2 diabetes in minority populations.⁵⁴

These may include:

• Developing policy and marketing to increase screening rates and uptake of lifestyle programs aimed at preventing diabetes.

• Training healthcare providers to better meet the needs of our diverse population through education on unconscious bias, diversity, and anti-racism.⁵⁵

• Providing equitable, effective, understandable, and respectful high-quality healthcare that considers cultural beliefs and practices while enhancing health literacy.

• Introducing payment reform to support high-risk people and allow them to receive healthcare.

• Diversifying the healthcare workforce to make it more inclusive, such as increasing the amount of bilingual and culturally competent healthcare providers.⁵⁶

The lowdown

Type 2 diabetes disproportionately affects minority populations, such as Black and Hispanic people. Even with the high rates of the disease, socioeconomic factors and systemic racism means many people remain undiagnosed and unaware of their condition. 

Research needs to focus on developing interventions to improve diagnostic efforts in minority populations so treatment and prevention of complications can begin earlier. 

Frequently asked questions

What is the best diabetic medication for African Americans?

Metformin is usually the first-line treatment for type 2 diabetes, but it’s not equally effective for everyone. Some research suggests that Black adults are more responsive to metformin than people of European descent.⁵⁷ However, this may not be true for the entire Black population because people respond to medications differently.

Another study found that metformin is only effective in Black American youth less than half the time.⁵⁸ These findings suggest that your doctor should determine the most suitable medication based on personal factors rather than race alone.

Can type 2 diabetes be reversed?

It’s easiest to prevent type 2 diabetes from developing in the first place by catching it at the prediabetes stage.

However, people with type 2 diabetes can often reverse their insulin resistance and the disease by making dietary changes, increasing their physical activity, and sometimes taking medication and supplements.

Still, this can depend on the person, and the complexity of the endocrine and metabolic issues in diabetes may prevent reversal.