Latent autoimmune diabetes in adults (LADA) is a form of diabetes that sits between type 1 and type 2, often causing confusion for both patients and doctors. Sometimes called “type 1.5 diabetes,” this condition involves the body slowly attacking its own insulin-producing cells, leading to gradually worsening blood sugar problems that can take months or even years to become severe.

What Makes LADA Different

Latent autoimmune diabetes in adults is a unique condition that shares features with both the more commonly known types of diabetes. Like type 1 diabetes, LADA happens because the immune system mistakenly creates antibodies—special proteins that normally fight infections—that attack and destroy the beta cells in the pancreas. Beta cells are the specialized cells responsible for making insulin, the hormone that allows sugar to enter cells and be used for energy. However, unlike classic type 1 diabetes which typically appears in children and teenagers and progresses rapidly, LADA develops slowly in adults, usually after age 30.^[1]

Because the destruction of beta cells happens gradually over months to years, people with LADA may still produce some insulin when first diagnosed. This partial insulin production makes the condition appear similar to type 2 diabetes, which is why many people with LADA are initially misdiagnosed. In type 2 diabetes, the problem is mainly that the body becomes resistant to insulin’s effects, rather than an immune system attack. The slow progression of LADA means that patients might not need insulin injections immediately, unlike those with classic type 1 diabetes who require insulin from the moment of diagnosis to survive.^[2]

How Common Is This Condition

Although many people have never heard of LADA, it is surprisingly common. Research studies suggest that between 4% and 12% of adults who initially receive a type 2 diabetes diagnosis actually have LADA instead. The numbers vary somewhat depending on the geographic location and the specific population studied, with European countries reporting rates between 4% and 12%, while Asian countries show rates between 3.8% and 9%.^[4]

To put these percentages in perspective, approximately 530 million adults worldwide currently live with type 2 diabetes. This means that several million people globally may actually have LADA rather than type 2 diabetes. The condition is diagnosed most often in adults between ages 30 and 50, which is older than the typical age for type 1 diabetes diagnosis but younger than many people develop type 2 diabetes.^[1]

In one significant study called the U.K. Prospective Diabetes Study, researchers tested 5,000 patients with type 2 diabetes and found that 10% actually had antibodies indicating LADA. Interestingly, the presence of these antibodies was much higher in younger patients—34% of those aged 25 to 34 years tested positive for the antibodies associated with autoimmune diabetes.^[3]

What Causes LADA to Develop

The underlying cause of LADA is an autoimmune process, meaning the body’s own immune system turns against itself. In this case, the immune system produces antibodies that specifically target and destroy the insulin-producing beta cells in the pancreas. When these cells are damaged or destroyed, the pancreas gradually loses its ability to make insulin. Without sufficient insulin, sugar (glucose) cannot enter the body’s cells properly and instead builds up in the bloodstream, leading to high blood sugar levels and diabetes symptoms.^[1]

The exact reason why the immune system begins attacking beta cells in LADA remains unclear to researchers. What makes LADA particularly puzzling is why the autoimmune destruction happens so much more slowly compared to classic type 1 diabetes. Some experts believe this slower progression may be related to a lighter genetic load—meaning that while genetics play a role, the genetic factors in LADA may not be as strong or numerous as those in classic type 1 diabetes.^[4]

LADA is considered a polygenic disease, which means multiple genes are involved in its development. The condition shares some genetic risk factors with type 1 diabetes and some with type 2 diabetes, but it also has genetic characteristics that are unique to LADA itself. This genetic complexity helps explain why LADA behaves differently from both type 1 and type 2 diabetes.^[4]

Who Is at Higher Risk

LADA has a strong genetic component, meaning that family history plays an important role. If your biological parents or grandparents have LADA or type 1 diabetes, you may have a higher chance of developing the condition yourself. However, having family members with diabetes does not guarantee that you will develop LADA—it simply means your risk is elevated compared to someone without this family history.^[1]

Beyond genetics, several lifestyle and environmental factors appear to influence the risk of developing LADA. Research has shown that obesity increases the risk, particularly when combined with having diabetes in the family. This connection to body weight is somewhat similar to type 2 diabetes risk factors. Physical inactivity also appears to increase LADA risk, while regular physical activity may have a protective effect.^[7]

Certain dietary factors have been linked to LADA risk. Studies indicate that consumption of sweetened beverages and processed red meat may increase the likelihood of developing the condition. Coffee consumption has shown unclear results in research, with some studies suggesting it might actually increase LADA risk—which differs from its protective effect against type 2 diabetes. On the other hand, eating fatty fish appears to have a protective effect against developing LADA.^[7]

Interestingly, low birth weight has been identified as a potential risk factor for LADA, in addition to its known association with type 2 diabetes. Smoking has been shown to increase the risk of type 2 diabetes, but its relationship with LADA remains less clear and requires further research.^[7]

Recognizing the Symptoms

The symptoms of LADA are similar to those seen in both type 1 and type 2 diabetes, as they all result from high blood sugar levels. However, the symptoms in LADA typically develop much more slowly than in type 1 diabetes—over months rather than weeks—while often appearing more obvious and progressing faster than what would be expected with type 2 diabetes.^[8]

One of the most common symptoms is excessive thirst, medically known as polydipsia. People with LADA may find themselves constantly thirsty and drinking much more fluid than usual. This happens because the body tries to flush out excess sugar through urine, leading to dehydration. Along with increased thirst comes polyuria, or frequent urination. High glucose levels in the blood lead to high glucose in the urine, which causes the kidneys to work harder to filter it out. Many people notice they need to urinate more often, especially at night, which can disrupt sleep.^[1]

Unexplained weight loss is another hallmark symptom of LADA. Because the body cannot use glucose properly for energy when insulin is insufficient, it begins breaking down fat and muscle tissue instead. This can lead to losing weight despite eating normally or even eating more than usual. Some people also experience increased hunger as the body tries to compensate for the lack of usable energy.^[6]

Blurred vision is a common symptom that occurs when high blood sugar levels cause changes in the eye. The excess sugar can damage blood vessels in the retina, affecting how clearly a person can see. Fatigue is another frequent complaint—people with LADA often feel unusually tired because their cells are not getting the glucose they need for energy. Itchy, dry skin can also develop as the body becomes dehydrated from excessive urination.^[1]

Preventing LADA or Slowing Its Progression

Because the exact causes of LADA are not fully understood and involve complex interactions between genetic and environmental factors, there is no guaranteed way to prevent the condition from developing. However, since lifestyle factors play a role in LADA risk, making healthy choices may help reduce the likelihood of developing the disease or slow its progression once it begins.^[2]

Maintaining a healthy weight through balanced eating and regular physical activity appears to be beneficial. While being overweight or obese increases LADA risk, it is important to note that many people with LADA have a normal or only slightly elevated body weight. This differs from type 2 diabetes, where excess weight is a major risk factor. Nevertheless, adopting healthy lifestyle habits can support overall metabolic health.^[3]

Regular physical activity has shown a protective effect against LADA in research studies. Exercise helps improve the body’s insulin sensitivity and metabolic function, which may help preserve beta cell function for longer. Making dietary choices that include fatty fish while limiting sweetened beverages and processed red meats may also be beneficial based on current research findings.^[7]

For people already diagnosed with LADA, early treatment with insulin has been suggested by some experts as a way to preserve remaining beta cell function and potentially slow the disease progression. The theory is that by taking insulin early, the pancreas does not have to work as hard, which might give the remaining beta cells a better chance of surviving longer. However, this approach has not yet been proven definitively in large prospective studies.^[3]

How the Body Changes in LADA

Understanding what happens inside the body during LADA helps explain why symptoms develop and why treatment is necessary. The disease process involves both autoimmune attack and gradual loss of pancreatic function. In LADA, the immune system produces specific antibodies that recognize beta cells as foreign invaders rather than normal body tissue. These antibodies trigger an inflammatory response that gradually damages and destroys beta cells over time.^[4]

As beta cells are destroyed, the pancreas produces less and less insulin. Insulin acts like a key that unlocks cells, allowing glucose from the bloodstream to enter and be used for energy. When insulin production declines, glucose cannot enter cells efficiently and instead accumulates in the blood. This creates a state of high blood sugar, or hyperglycemia, while the cells themselves remain starved for energy despite abundant glucose in the bloodstream.^[6]

The gradual nature of beta cell destruction in LADA distinguishes it from classic type 1 diabetes, where this process happens much more rapidly. In LADA, some beta cells continue functioning for months or years after diagnosis, which is why oral medications used for type 2 diabetes may work temporarily. However, as more beta cells are lost, these medications become less effective because there are fewer cells left to stimulate or support.^[2]

The rate of beta cell destruction can vary significantly between individuals with LADA. Some people progress to insulin dependence within one to two years, while others maintain partial beta cell function for longer. Factors that influence this rate include the specific antibodies present, the levels of those antibodies, genetic factors, and possibly lifestyle elements. Patients with higher levels of certain antibodies tend to lose beta cell function more quickly.^[5]

In addition to the autoimmune attack, some people with LADA also develop insulin resistance, similar to what occurs in type 2 diabetes. This means their cells do not respond as well to whatever insulin is still being produced. This combination of reduced insulin production due to autoimmune destruction and reduced insulin effectiveness due to resistance creates a complex metabolic situation that can require a combination of treatment approaches.^[4]