Diabetes MODY: Signs, Causes, Treatment, Lifestyle Changes

MODY stands for maturity-onset diabetes of the young. 

MODY describes diabetes that is more similar to type 2 diabetes than type 1 diabetes but occurs in younger people.

Compared to other types of diabetes, MODY is more rare and results from a genetic mutation. 

The most common type of MODY genetic mutation is HNF1-alpha, which is estimated to impact around 70% of people with MODY. 

This genetic mutation results in a reduction of the amount of insulin produced by the pancreas in people with MODY. 

However, patients with MODY aren’t necessarily insulin resistant like type 2, nor do they have insulin deficiency like type 1.

MODY typically impacts people under the age of 25, which is why it’s sometimes confused with other subsets of diabetes, such as latent autoimmune diabetes of adults (LADA) and type 1 diabetes. 

Signs and symptoms of MODY

The signs of MODY are the same as other types of diabetes and occur due to high blood glucose (blood sugar) levels. 

It’s possible to be developing MODY for months or years before you start to develop symptoms, which is why routine blood sugar screening is an important part of preventive health visits.

Some of the potential signs and symptoms of MODY can include:

• Frequent or increased urination (polyuria)
• Feeling more thirsty (polydipsia)
• Increased hunger
• Dehydration
• Changes in your vision, such as blurry vision
• Slowly-healing wounds
• Recurrent yeast infections and other types of infections

MODY is typically diagnosed with various blood tests, including genetic testing. 

In addition to genetic tests to look for gene mutations, other testing can include pancreatic antibodies and testing for C-peptide, which can help differentiate MODY from other types of diabetes. 

To diagnose MODY, here are some of the requirements:

• Onset before 25 years of age
• Presence of diabetes in two consecutive family generations
• Absence of β-cell autoantibodies (which indicates type 1 diabetes versus MODY)
• Blood C-peptide level of >200 pmol/L, which indicates normal insulin secretion (C-peptide is usually low in type 1 diabetes and high with regular type 2 diabetes)

What causes MODY?

Genetic mutation

MODY is caused by a genetic mutation, which is why it’s rarer than type 2 diabetes and type 1 diabetes.

If a parent has the gene for MODY, their children each have a 50% chance of developing MODY.

One of the characteristics that sets MODY apart from type 1 and 2 diabetes is that patients generally aren’t insulin-dependent and can be treated with either no insulin or a low insulin dose and/or oral diabetes drugs, most notably sulfonylureas.

Another aspect of MODY is that it can impact any ethnic group or gender, whereas type 2 diabetes is more common in certain ethnicities such as Native Americans, Latinos, and African Americans.

Other subsets of MODY

As mentioned earlier, the most common genetic mutation that causes MODY is HNF1-alpha. However, other types exist.

HNF4-alpha

This type of MODY typically occurs in people who have a birth weight of 9 pounds (~4 kilograms) or more, in addition to possibly having low blood sugar soon after birth. 

This subset of MODY usually requires insulin for treatment at some point after initially using a sulfonylurea (oral diabetes medication).

HNF1-beta

People with this type of MODY are more likely to need insulin treatment compared to other types. 

This type is also associated with other issues such as cysts on your kidneys, gout, and uterine abnormalities in women.

Glucokinase (also called GCK or MODY2)

This type of MODY is not typically associated with long-term health risks of diabetes (such as eye problems, nerve damage, and more) and doesn’t typically require treatment. 

Because it doesn’t have symptoms, it’s usually only detected during routine blood work, such as having blood tests done during pregnancy.

Treatment options for MODY

Treatment is usually required for all types of MODY except MODY2 (GCK). Some of the preferred treatment options for MODY are listed below.

Sulfonylureas

The first-line treatment for MODY is the use of a sulfonylurea, a type of oral diabetes medication. Sulfonylureas stimulate your pancreas to secrete more insulin.

Sulfonylureas come with a risk of low blood sugar (hypoglycemia), which sets them apart from other popular oral diabetes medications like metformin (predominately used to treat type 2 diabetes).

The sulfonylureas used today (second-generation versions) include:

• Gliclazide (common brand name Diamicron)
• Glipizide (common brand name Glucotrol)
• Glibenclamide (common brand name Glynase)
• Glimepiride (common brand name Amaryl)
• Glyburide (only available as a generic)

Insulin

Insulin isn’t typically required for the most common type of MODY (HNF1-alpha), and if it is required, it’s usually only needed in low doses.

Some patients with MODY might require insulin, which is injected under the skin. Insulin treatment usually consists of long-acting insulin (basal insulin) with or without a shorter-acting insulin (also called bolus or mealtime insulin).

Common long- and ultra-long-acting insulin include:

• Insulin glargine (Lantus, Basaglar, Toujeo)
• Insulin detemir (Levemir)
• Insulin degludec (Tresiba)

Common short- and rapid-acting insulin include:

• Insulin lispro (Humalog)
• Insulin aspart (Novolog)
• Regular insulin (Humulin R)

Natural lifestyle changes to help manage MODY symptoms

In addition to pharmacological treatment, lifestyle changes are recommended for all types of diabetes, including MODY.

Diet and diabetes

One of the most important lifestyle habits to address with MODY is your food and drink choices. Diet is strongly linked to blood sugar control since certain foods are broken down into glucose after you eat them.

Carbohydrates (also called carbs) are a type of nutrient your body uses for energy and are found in foods like:

• Grains
• Legumes
• Fruits
• Vegetables
• Some dairy products like milk and yogurt

Carbs are also found in sugars, both natural (like honey) and refined (like table sugar). 

Many vegetables are very low in carbohydrates, but a few vegetables are considered starchy, which means they’re higher in carbs and can raise your blood sugar levels more significantly. 

Some examples of starchy vegetables include:

• Potatoes
• Winter squash
• Corn
• Peas

Because they contain sweeteners like table sugar, corn syrup, and others, sweetened foods are higher in carbs. Examples include:

• Cold cereals
• Flavored yogurt
• Sugary drinks
• Many other processed foods

Diet changes

You don’t have to follow a low-carb diet like the ketogenic diet to effectively manage your blood sugar with MODY. 

Instead, aim to reduce added sugars and refined carbs and replace them with nutrient-rich carbohydrates like whole grains, fruits, and vegetables. 

In addition to choosing healthier carbs and cutting down on added sugar, make sure to include plenty of protein in your diet, which can help stabilize blood sugar levels. 

Another bonus of protein is that it doesn’t raise blood sugar like carbs do.

Some examples of protein to include in your diet include:

• Meat 
• Poultry
• Eggs
• Nuts and seeds
• Legumes, including soybeans
• Dairy products like yogurt, cheese, milk, and whey protein

Physical activity

Being active is one of the best ways to promote healthy blood sugar levels. Besides controlling blood sugar levels, physical activity is linked with better mental health and heart health and can help reduce the likelihood of developing chronic diseases.

Aim to get a mix of cardiovascular activity (such as walking, jogging, and swimming) in addition to strength training to build muscle. 

The more muscle you have, the less likely you are to have insulin resistance, according to research.

Simple bodyweight exercises like lunges and squats are beneficial for strength training, so you can build muscle even without using weights. You can also use resistance bands for low-impact resistance training.

Vitamins and supplements

There are countless vitamins and supplements available, but not all of them are proven to help control blood sugars. 

Certain vitamins and minerals, such as magnesium and vitamin D, are associated with improved insulin sensitivity.

If you’re interested in learning more about which vitamins, minerals, and other supplements might help improve your health with MODY, reach out to your primary care provider or registered dietitian for guidance.

What is the difference between diabetes and MODY?

MODY is caused by a genetic mutation, whereas type 1 and type 2 diabetes are not. MODY is also different because it’s more similar to type 2 diabetes in presentation, but occurs in younger patients.

Is MODY an autoimmune disease?

Unlike type 1 diabetes, MODY isn’t an autoimmune disease. Instead, it’s caused by a genetic mutation and presents more like type 2 diabetes but in younger patients (under the age of 25).

Is MODY insulin resistance?

Patients with MODY can have insulin resistance, but it’s not always the case. MODY results in reduced insulin secretion, but that doesn’t mean patients with MODY are resistant to insulin. 

Insulin resistance is the root cause of type 2 diabetes, which is one of many ways MODY is different from more common types of diabetes.

What are the HbA1c levels in MODY patients?

A1c levels can be as low as 5.6% in patients with MODY2 (the least harmful type) but are generally above 6.5% in other types of MODY. 6.5% is the starting A1c level, indicating diabetes, with higher A1c levels indicating high blood sugar levels.

Conclusion

• MODY stands for “maturity-onset diabetes of the young” and is a type of diabetes that usually impacts people under the age of 25.
• Unlike type 1 and type 2 diabetes, MODY is caused by a genetic mutation. It’s not an autoimmune disease like type 1 and isn’t caused by insulin resistance like type 2.
• MODY is more similar to type 2 diabetes but occurs in younger patients (usually under the age of 25 instead of the more typical age of 45 and older).
• Some types of MODY don’t require treatment, while most forms require sulfonylureas and/or a lower dose of insulin therapy.

Explore More

What You Need to Know About Type 1.5 Diabetes (LADA).