There are several types of diabetes, other than type 1 and type 2 diabetes. Below is a description of some of these types of diabetes:

• Gestational Diabetes
• MODY
• Type 3 Diabetes
• Type 3c Diabetes
• LADA
• NODAT
• Endocrine causes for diabetes
• Medication causing diabetes
• Genetic causes for diabetes
• Problems with pancreas leading to diabetes

Gestational Diabetes

Gestational diabetes occurs when you have high blood glucose levels during pregnancy. Gestational diabetes is usually developed in the third trimester, that is between 24 and 28 weeks.  Diabetes typically disappears after the baby is born. Women who develop gestational diabetes during pregnancy are much more likely to develop type 2 diabetes later on in life.

Gestational diabetes can lead to problems to both mother and baby if not treated. As baby is larger, there is difficulty during delivery and premature birth is known to occur. There is an increased likelihood of caesarean section. Baby, may also have low blood glucose and/or jaundice. Mothers have an increased risk of developing pre-eclampsia.

Usually there are no symptoms of gestational diabetes. Gestational diabetes is usually diagnosed during screening. Symptoms when they do occur are similar to the normal symptoms of diabetes, which include: excessive thirst and urination. Sometimes these symptoms could be masked by how women feel during early pregnancy.

Women in the following categories have a risk of gestational diabetes

• Obese women
• Previous large babies (more than 10lb)
• Asian, Black or African-Caribbean origin
• Previous history of gestational diabetes

It is always important to see a diabetes specialist, if you are concerned about gestational diabetes. Gestational diabetes should be managed by the obstetric and the diabetes team.

MODY

MODY or Maturity Onset Diabetes of Young is a rare form of diabetes which runs strongly in families. MODY is caused by a mutation of a single gene.

People with MODY are usually:

• Diagnosed with diabetes under the age of 25.
• Have at least one parent with diabetes, and a history of diabetes in two or more generations.
• Do not need insulin.

About 90% of people with MODY are mistakenly diagnosed with Type 1 or Type 2 diabetes.

The most common types of MODY are:

• HNF1-alpha.This gene causes about 70 per cent of cases of MODY
• HNF4-alph
• HNF1-beta
• Glucokinase

All types of MODY apart from glucokinase carry a risk of the long-term complications of diabetes.

If you suspect that you have MODY you should see a diabetes specialist.

Investigations for MODY includes:

• Blood for antibodies and urine tests to check for C-peptide
• Genetic testing, which is processed in Exeter.

More information on MODY and monogenetic diabetes can be obtained from this website: www.diabetesgenes.org

Type 3 Diabetes

This condition also has been used by some to describe people who have type 2 diabetes and are also diagnosed with Alzheimer’s disease dementia. The classification of type 3 diabetes is highly controversial.

Some scientist feel that Alzheimer’s disease could be due to insulin resistance. Loosely it has been called: “Diabetes of Brain”.

People with type 2 diabetes, if not well controlled can have poor blood supply to the brain, affecting small blood vessels. This results in reduced blood supply to several areas in the brain, leading to vascular dementia.

Symptoms of type 3 diabetes are similar to symptoms of dementia, such as memory loss, difficulty completing familiar tasks and sudden change in personality.

There are no specific investigations for type 3 diabetes. Dementia in general is diagnosed based on a neurological examination, neurophysiological testing, CSF test and an MRI.

Treating type 2 diabetes and adapting healthy life style reduces the risk of dementia.

Type 3c Diabetes

The pancreas has both endocrine and exocrine function. Endocrine function of the pancreas is to produce hormones like insulin by the beta cells, glucagon by the alpha cells and other hormones.

When the exocrine pancreas becomes diseased, it affects the endocrine pancreas, which leads to type 3c diabetes. This may be due to:

• chronic pancreatitis
• cystic fibrosis
• exocrine pancreatic cancer

What is LADA or type 1.5 diabetes?

LADA or Latent Onset Diabetes of Adults, also called type 1.5 diabetes, is a type of diabetes like type 1 diabetes, with some features of type 2 diabetes.

The symptoms of LADA are the same as diabetes, which include excessive urination, thirst, weight loss and tiredness.

These are some of the characteristics of people with LADA:

• Age of onset above 30 years
• Family or personal history of autoimmune disorders
• Lower body mass index and blood pressure compared to people with type 2 diabetes

LADA generally develops much slower than type 1 diabetes. People with LADA have usually normal BMI. Diagnosing LADA can be difficult and some people are diagnosed with having type 2 diabetes by mistake.

If you have LADA, you may have antibodies detected like in type 1 diabetes.

People with LADA are usually treated with oral medications but may soon be commenced on insulin. There is no separate protocol for management of diabetes and hence treatment should be personalised.

Some diabetologists manage LADA based on C-peptide levels.

NODAT

New-onset Diabetes After Transplantation (NODAT): This is a serious form of diabetes and is a frequent metabolic complication after kidney transplantation. Development of NODAT depends on immunosuppression regimen used. NODAT is usually seen during the first 6 months after transplantation.

Kidney transplant recipients with NODAT develop complications like other people with type 2 diabetes, but complications develop rapidly. NODAT patients should therefore be monitored frequently and regularly by the diabetes team.

Endocrine causes of Diabetes

In addition to the above causes of diabetes, there are several other reasons why someone could develop diabetes. Some hormone disorders like:

• Acromegaly
• Cushing’s syndrome
• Glucagonoma
• Pheochromocytoma
• Thyrotoxicosis
• Aldosteronoma (Conns Syndrome)
• Somatostatinoma

If you have any concerns about the type of diabetes, it is important see an endocrinologist near you for appropriate investigation and management.

Medications which could lead to diabetes

• Olanzepine and other antipsychotics
• Steroids
• Alpha-interferon
• Thiazides

Infections like rubella and cytomegalovirus also can cause diabetes.

Genetic causes for Diabetes

• Downs syndrome
• Turners syndrome
• Klinefelters syndrome
• Prader-Willi syndrome
• Porphyria and many more….

Problems with pancreas leading to Diabetes

• Recurrent pancreatitis or inflammation of pancreas
• Pancreatic cancer
• Injury to pancreas
• Haemochromatosis (increased iron load)
• Cystic fibrosis

Dr Chinnadorai Rajeswaran is a consultant Physician specialising in Endocrinology, Diabetes and Obesity. As a private endocrinologist he  has private endocrine, diabetes and weight loss clinics in Harley Street, London, Chennai (India), Claremont Hospital, Sheffield, Nuffield Hospital, Leeds and Simplyweight, Bradford.

He has face to face consultations with people from Barnsley, Rotherham, Chesterfield, Doncaster, Wakefield, Huddersfield, Bradford, Harrogate, Leeds, Sheffield, London and Chennai (India). He also offers video consultations.