Type 1.5 diabetes?

Karen Staveley

Karen Staveley

It took three years and a heart attack before Karen Staveley was properly diagnosed with a slow-onset form of type 1 diabetes. Words and photos by Karen Reed.

Most people have heard about type 1 and type 2 diabetes, even if they are a bit fuzzy about the differences (more of this later).

But how many know someone with a third type of diabetes, called LADA, sometimes referred to as type 1.5 diabetes?

Latent Autoimmune Diabetes in Adults, or LADA for short, is a slow-onset form of type 1 diabetes that can be misdiagnosed as type 2 diabetes, sometimes with serious health consequences.

Diabetes NZ wants to raise awareness of LADA because up to 10% of people diagnosed with type 2 diabetes may actually have this form of diabetes. The treatment pathway is very different for each condition.

Karen Staveley, of Rotorua, knows only too well the impact of being misdiagnosed because it almost killed her.

She was diagnosed with type 2 diabetes in November 2011 after several months of being unwell with shingles. She was first prescribed metformin, however her blood glucose levels remained high (in the 20s).

Karen, a supermarket checkout supervisor, was slim and underweight for her height. She had felt tired and unwell for three years, suffering unexplained and recurrent periods of thrush and urinary infections.

“It was a miserable period,” she recalls. “I was continually feeling unwell. At one stage I became really sick with pneumonia. My blood sugar level was 31.”

Karen decided to take part in a clinical trial being run in Rotorua. She started once-a-day long-acting insulin injections. But this didn’t make her feel any better. Then she developed another serious bladder infection and was prescribedantibiotics. Taking them, she had what was thought to be an allergic reaction – she became short of breath and had serious chest pain. After an ambulance was called, she was given antihistamine and sent home.

Four hours later, another ambulance was called – Karen had suffered a heart attack. The cardiac team at Waikato referred her to specialists at Rotorua Hospital. Eventually, with blood glucose levels still persistently in the 20s, she was diagnosed with a slow-onset form of type 1 diabetes called LADA.

Karen knew they had the diagnosis right this time because just one injection of a fast-acting insulin, Novorapid, made her feel so much better.

“It was such a relief to be properly diagnosed, three years after my initial type 2 diagnosis. I felt alive again, it was amazing. And I still feel so much better now.”

But the misdiagnosis of her diabetes as type 2 – and subsequent inadequate treatment – caused three years of suffering that Karen could have done without.

“I still feel angry sometimes about the length of time it took to get the correct diagnosis.

“It’s been a bit of a journey, but I’m pleased to be feeling well again and I now have my blood glucose levels under control.”

Karen says it took a while to readjust her mindset from having type 2 diabetes to having type 1. Instead of concentrating on a general low-carb low-fat low-sugar kind of diet with lots of exercise, she had to start thinking about carb counting and adjusting her insulin doses to get the ratio of insulin to carbs right.

“It took me a while to get the hang of things, but I feel so much better now, it’s incredible,” she adds.

Karen’s specialist Dr Nic Crook confirmed her LADA diagnosis.

If you think you may have LADA, talk to your GP or diabetes provider. There are blood tests available to confirm this type of diabetes.

 

WHAT IS SLOW-ONSET TYPE 1 DIABETES?

This type of diabetes has been referred to as type 1.5 diabetes because it is a form of type 1 diabetes but shares features more commonly associated with type 2 diabetes.

LADA, or Latent Autoimmune Diabetes in Adults, is diagnosed during adulthood like most cases of type 2 diabetes.

However, LADA is an autoimmune disease, like type 1 diabetes, and sooner or later the insulin-producing beta cells in the pancreas will be destroyed. Eventually insulin is needed for survival, usually within a few years of type 2 diagnosis.

Some features of LADA may include:

• being slim, or at least not overweight

• a history of autoimmune problems

• no ketoacidosis at diagnosis

• a positive GAD antibody test (blood test)

• the patient may need insulin relatively soon after initial diagnosis – usually within 3-5 years

MISDIAGNOSIS COMMON

Up to 10% of people diagnosed with type 2 diabetes may actually have LADA, according to endocrinologist Dr Rick Cutfield, of Waitemata District Health Board.

The consequences of misdiagnosis could be grave – as they were for Karen – or of little impact. Metformin is the first medication usually given when someone is diagnosed with type 2 diabetes. This helps reduce insulin resistance, a key feature in the majority of cases.

However people with immune-mediated diabetes, like LADA or type 1 diabetes, have little or no resistance to insulin. Quite the opposite – they are sensitive to insulin so metformin doesn’t work for them.

Other medications for type 2, which increase insulin production, may work for a while in people with LADA. This often means their misdiagnosis takes longer to recognise.

Doctors are encouraged to consider the possibility of LADA in cases of type 2 diabetes that don’t fit usual clinical features.

 

WHY DOES TYPE 1 DIABETES DEVELOP EARLY IN LIFE IN SOME PEOPLE BUT LATER IN LIFE IN OTHERS?

Karen Reed

Karen Reed

The current line of thinking is that our genes provide a risk/susceptibility to (or possibly protection from) type 1 diabetes. Whether you develop T1 depends on the interplay of our genes with environmental factors.

My family history tells a story in itself. My father was 15 years old when he developed diabetes, his sister was 27, and his brother 38 when they were diagnosed. They all had type 1 diabetes.

If the genetic causes in each of the siblings were similar, then the initiation and/or the length of the disease process was presumably more related to environmental factors.

By the way, I was 10 years old when I was diagnosed with T1. – Karen Reed

 

Aimee shared her story in the Winter 2019 issue of Diabetes magazine.  Subscribe to Diabetes NZ today to receive your copy.

To read back issues, visit here.

 
Jo Chapman