OVERVIEW

What is Mitochondrial Diabetes?

Mitochondrial diabetes is a rare form of diabetes caused by mitochondrial gene defects, inherited maternally.

It typically develops early, often between ages 30-40. In addition to classic diabetes symptoms (polyphagia, polydipsia, polyuria, and weight loss), it is frequently accompanied by sensorineural hearing loss.

Dietary restrictions may be relaxed slightly in treatment, with greater reliance on insulin for blood sugar control. Biguanides are contraindicated.

Is Mitochondrial Diabetes Common?

It has an extremely low incidence rate and is considered a rare type of diabetes.

SYMPTOMS

What are the manifestations of mitochondrial diabetes?

• Maternal inheritance: The patient's mother usually also has diabetes.

• Sensorineural hearing loss: Over 60% of patients experience varying degrees of bilateral hearing impairment, which may occur before or after diabetes onset and worsens with age.

• Weight loss: Patients typically have a lean body type at the time of onset.

• Early onset: It generally occurs around 35–40 years of age.

• Pancreatic β-cell function: Progressive decline is observed, with 3243A→G mutation carriers showing significantly faster deterioration compared to typical type 2 diabetes patients.

• Associated symptoms: Such as neuromuscular disorders, cardiomyopathy, arrhythmias, etc.

CAUSES

What is the cause of mitochondrial diabetes?

The cause is a defect in mitochondrial genes, most commonly the 3243A→G mutation.

Is mitochondrial diabetes hereditary?

Yes, it is hereditary.

It follows maternal inheritance, meaning children of female patients may inherit the condition (though not all will), while children of male patients will not.

DIAGNOSIS

What tests may be needed for mitochondrial diabetes?

In addition to blood glucose measurement, genetic mutation testing is also required.

Which diseases can mitochondrial diabetes be easily confused with?

Some cases of mitochondrial diabetes are often misdiagnosed as type 2 diabetes.

TREATMENT

Which department should I visit for mitochondrial diabetes?

Endocrinology.

How is mitochondrial diabetes treated?

Patients with mitochondrial diabetes tend to be underweight, so dietary restrictions can be appropriately relaxed.

In the early stages, oral hypoglycemic drugs may be used, but after a few years, oral medications may become ineffective, and insulin therapy should be initiated early.

Biguanides are not recommended because they inhibit mitochondrial redox capacity and may increase the risk of lactic acidosis, so they should not be used.

How effective is the treatment for mitochondrial diabetes?

Blood sugar control is slightly more challenging compared to type 2 diabetes.

Does mitochondrial diabetes affect fertility?

No.

However, female patients may pass the disease and defective genes to the next generation.

DIET & LIFESTYLE

What should patients with mitochondrial diabetes pay attention to in their daily life and diet?

Patients with mitochondrial diabetes tend to be underweight, so dietary restrictions can be appropriately relaxed. Due to elevated blood lactate levels, they should only engage in light exercise.

PREVENTION

Can mitochondrial diabetes be prevented and screened?

There are no preventive measures. Women with a family history are advised to undergo pre-pregnancy testing.