Image copyright Getty Images Image caption Could there be five types of diabetes rather than just two? 
 
 Scientists say diabetes is five separate diseases, and treatment could be tailored to each form. 
 
 Diabetes - or uncontrolled blood sugar levels - is normally split into type 1 and type 2. 
 
 But researchers in Sweden and Finland think the more complicated picture they have uncovered will usher in an era of personalised medicine for diabetes. 
 
 Experts said the study was a herald of the future of diabetes care but changes to treatment would not be immediate. 
 
 Diabetes affects about one in 11 adults worldwide and increases the risk of heart attack, stroke, blindness, kidney failure and limb amputation. 
 
 Type 1 diabetes is a disease of the immune system, which affects around 10% of people with the condition in the UK. It errantly attacks the body's insulin factories (beta-cells) so there is not enough of the hormone to control blood sugar levels. 
 
 Type 2 diabetes is largely seen as a disease of poor lifestyle as body fat can affect the way the insulin works. 
 
 The study, by Lund University Diabetes Centre in Sweden and the Institute for Molecular Medicine Finland, looked at 14,775 patients including a detailed analysis of their blood. 
 
 The results, published in The Lancet Diabetes and Endocrinology, showed the patients could be separated into five distinct clusters. 
 
 Cluster 1 - severe autoimmune diabetes is broadly the same as the classical type 1 - it hit people when they were young, seemingly healthy and an immune disease left them unable to produce insulin 
 
 Cluster 2 - severe insulin-deficient diabetes patients initially looked very similar to those in cluster 1 - they were young, had a healthy weight and struggled to make insulin, but the immune system was not at fault 
 
 Cluster 3 - severe insulin-resistant diabetes patients were generally overweight and making insulin but their body was no longer responding to it 
 
 Cluster 4 - mild obesity-related diabetes was mainly seen in people who were very overweight but metabolically much closer to normal than those in cluster 3 
 
 Cluster 5 - mild age-related diabetes patients developed symptoms when they were significantly older than in other groups and their disease tended to be milder 
 
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 Prof Leif Groop, one of the researchers, told the BBC: "This is extremely important, we're taking a real step towards precision medicine. 
 
 "In the ideal scenario, this is applied at diagnosis and we target treatment better." 
 
 The three severe forms could be treated more aggressively than the two milder ones, he said. 
 
 Cluster 2 patients would currently be classified as type 2 as they do not have an autoimmune disease. 
 
 However, the study suggests their disease is probably caused by a defect in their beta-cells rather than being too fat. 
 
 And perhaps their treatment should more closely mirror patients who are currently classed as type 1. 
 
 Cluster 2 had a higher risk of blindness while cluster 3 had the greatest risk of kidney disease, so some clusters may benefit from enhanced screening. 
 
 Better classification 
 
 Dr Victoria Salem, a consultant and clinical scientist at Imperial College London, said most specialists knew that type 1 and type 2 was "not a terribly accurate classification system". 
 
 She told the BBC: "This is definitely the future of how we think about diabetes as a disease." 
 
 But she cautioned the study would not change practice today. 
 
 The study was only on Scandinavians and the risk of diabetes varies considerably around the world, such as the increased risk in South Asians. 
 
 Dr Salem said: "There is still a massively unknown quantity - it may well be that worldwide there are 500 subgroups depending on genetic and local environment effects. 
 
 "Their analysis has five clusters, but that may grow." 
 
 Sudhesh Kumar, a professor of medicine at Warwick Medical School, said: "Clearly this is only the first step. 
 
 "We also need to know if treating these groups differently would produce better outcomes." 
 
 Dr Emily Burns, from Diabetes UK, said understanding the diseases could help "personalise treatments and potentially reduce the risk of diabetes-related complications in the future". 
 
 She added: "This research takes a promising step toward breaking down type 2 diabetes in more detail, but we still need to know more about these subtypes before we can understand what this means for people living with the condition." 
 
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 Adults with diabetes could benefit from better treatment if the condition was categorized into five types, rather than just two. This is the conclusion of a new study published in The Lancet Diabetes & Endocrinology. 
 
 
 
 Researchers say that diabetes should be categorized into five types, rather than two. Researchers say that diabetes should be categorized into five types, rather than two. 
 
 The research was led by Prof. Leif Groop, of the Lund University Diabetes Centre in Sweden and the Institute for Molecular Medicine Finland in Helsinki. 
 
 In the United States alone, around 30.3 million people are living with diabetes. 
 
 Excluding gestational diabetes — diabetes that develops during pregnancy — there are two main types: type 1 and type 2. 
 
 In type 1 diabetes, the beta cells of the pancreas — which produce insulin, the hormone that regulates blood sugar levels — are mistakingly attacked and destroyed by the immune system. 
 
 Type 2 diabetes is the most common form, accounting for around 90–95 percent of all cases. This occurs when the body's cells stop responding to insulin, or the beta cells are unable to produce sufficient amounts of the hormone. 
 
 In both forms of the condition, blood sugar levels can become too high — a condition known as hyperglycemia. Unless controlled, this can lead to a number of complications, including kidney disease, cardiovascular disease, and nerve damage. 
 
 The heterogeneity of diabetes 
 
 A diabetes diagnosis is normally made using the fasting plasma glucose (FPG) test or the A1C test. The FPG test assesses a person's blood glucose level at a single time point, while the A1C test measures average blood glucose levels over the previous 3 months. 
 
 When it comes to determining which type of diabetes a person has, healthcare professionals might look for diabetes-related autoantibodies in the blood. These are proteins produced by the immune system that can attack the body's own cells. 
 
 The presence of such autoantibodies is an indicator of type 1 diabetes. If a person does not have these autoantibodies, they are considered to have type 2 diabetes. 
 
 But, as Prof. Groop and colleagues note, the classification guidelines for diabetes have not been updated for 20 years — despite increasing evidence that diabetes has high heterogeneity. 
 
 "Diabetes is a group of chronic metabolic disorders," says Dr. Rob Sladek, of the McGill University and Génome Québec Innovation Centre in Canada, in an editorial linked to the study, "that share the common feature of hyperglycemia, meaning that, in principle, diabetes can be diagnosed via measurement of a single blood component." 
 
 "However, elevations in blood glucose can be caused by a number of genetic and acquired factors that reduce the circulating concentrations of insulin or decrease its effectiveness, leading to heterogeneity in the clinical presentation and progression of the disease." 
 
 Prof. Groop and his team say that a "refined classification" of diabetes based on its heterogeneity could help healthcare professionals better predict which individuals are most likely to develop complications and allow a more personalized approach to treatment. 
 
 In their study, the researchers propose that diabetes should no longer be categorized as two types. Instead, they say that the condition should be classified into five distinct types. 
 
 The five 'clusters' of diabetes 
 
 The researchers came to their proposal by analyzing the data of four study cohorts. These included a total of 14,775 adults from Sweden and Finland, all of whom had been newly diagnosed with diabetes. 
 
 As part of the analysis, the scientists looked at six measures in each subject that each represent different features of diabetes. 
 
 These measures were: body mass index (BMI); age at diabetes diagnosis; hemoglobin A1C (HbA1C), a measure of long-term blood sugar control; beta cell functioning; insulin resistance; and the presence of diabetes-related autoantibodies. 
 
 As well as conducting genetic analyses of the participants, the researchers also compared their disease progression, complications, and treatment. 
 
 The study revealed five distinct forms of diabetes, three of which were severe and two that were mild. The team categorized these as follows: 
 
 Cluster 1 : severe autoimmune diabetes (currently known as type 1 diabetes), characterized by insulin deficiency and the presence of autoantibodies. This was identified in 6–15 percent of subjects. 
 
 : severe autoimmune diabetes (currently known as type 1 diabetes), characterized by insulin deficiency and the presence of autoantibodies. This was identified in 6–15 percent of subjects. Cluster 2 : severe insulin-deficient diabetes, characterized by younger age, insulin deficiency, and poor metabolic control, but no autoantibodies. This was identified in 9–20 percent of subjects. 
 
 : severe insulin-deficient diabetes, characterized by younger age, insulin deficiency, and poor metabolic control, but no autoantibodies. This was identified in 9–20 percent of subjects. Cluster 3 : severe insulin-resistant diabetes, characterized by severe insulin resistance and a significantly higher risk of kidney disease. This was identified in 11–17 percent of subjects. 
 
 : severe insulin-resistant diabetes, characterized by severe insulin resistance and a significantly higher risk of kidney disease. This was identified in 11–17 percent of subjects. Cluster 4 : mild obesity-related diabetes, most common in obese individuals. This affected 18–23 percent of subjects. 
 
 : mild obesity-related diabetes, most common in obese individuals. This affected 18–23 percent of subjects. Cluster 5: mild age-related diabetes, most common in elderly individuals. This was the most common form, affecting 39–47 percent of subjects. 
 
 The researchers note that each of these five types "were also genetically distinct," meaning that there were no genetic mutations that were shared across all five clusters. 
 
 A 'step toward precision medicine' 
 
 When the researchers assessed the treatment received by adults in each of the five clusters, they noticed that some were being treated inappropriately. 
 
 As an example, the team points out that just 42 percent of patients in cluster 1 and 29 percent of patients in cluster 2 received insulin therapy from the point of disease onset. 
 
 They say that this indicates that the current classifications of diabetes fail to target the underlying features of the disease. 
 
 As such, Prof. Groop and colleagues propose that diabetes should be categorized into five distinct types. 
 
 While further research is required to refine these five clusters — by using biomarkers and genetic risk scores, for example — the team believes that this study is a great stride toward tailored treatments for diabetes. 
 
 "Existing treatment guidelines," concludes Prof. Groop, "are limited by the fact they respond to poor metabolic control when it has developed, but do not have the means to predict which patients will need intensified treatment. 

 Findings shed light on variations in response to treatment between diabetics –and could help identify those at high risk of complications 
 
 Diabetes that begins in adulthood falls into five distinct categories, new research has revealed, with scientists suggesting it is time to ditch the idea that diabetes is largely split into two types. 
 
 Researchers say all of the newly classified subgroups are genetically distinct and have numerous differences, including the age at which they tend to occur and different levels of risk for complications such as kidney disease. 
 
 
 
 Diabetes diagnoses have more than doubled in 20 years, UK analysis suggests Read more 
 
 The team say the findings shed light on why some diabetics respond very differently to treatment than others, adding that it could help identify those who might be at high risk of complications, and lead to tailored treatment of the disease. 
 
 
 
 “For the patient, I think it will mean a more individualised therapy [and] a better quality of life,” said Leif Groop, professor of diabetes and endocrinology at Lund University, who led the study. 
 
 At present, diabetes is classified into two main forms, both of which have links to genetics. Type 1 is an autoimmune condition where the hormone insulin is not produced, and which generally develops in childhood. The more common form, type 2, in which little insulin is produced or does not trigger glucose uptake by the body’s cells, generally develops later in life and is linked to obesity. 
 
 
 
 However, the latest study suggests this classification is too simplistic. 
 
 
 
 Writing in the journal The Lancet Diabetes and Endocrinology, researchers describe how they discovered the five sub-groups by analysing information from 8,980 diabetics diagnosed as adults in a Swedish registry. The results were confirmed using data from 5,795 other adult patients across another three further databases from Sweden and Finland. 
 
 The team say the findings show that type 1 diabetes and a late-onset autoimmune form of diabetes can be grouped together as one form, dubbed severe autoimmune diabetes. 
 
 
 
 However the researchers say what would generally have been called “type 2” diabetes in fact encompasses four categories, two of which are severe forms of the disease. 
 
 One, dubbed severe insulin-deficient diabetes, shows similar features to the autoimmune group such as relatively low body mass index (BMI), lack of insulin and early onset, but did not have telltale antibodies indicating an autoimmune disease. Diabetic eye disease was most common in this group. 
 
 
 
 While this group had the highest proportion of patients on the drug metformin, Groop said this was not the optimum treatment. “They clearly need insulin very soon, almost as much as ‘type 1’,” he said. 
 
 The other severe category, called severe insulin-resistant diabetes, is linked to obesity and shows a strong tendency for the body’s cells not to respond to insulin, with these patients showing the highest likelihood of having liver disease, chronic kidney disease, and diabetic kidney disease. This group had a low proportion of patients taking metformin, although the authors say they would be expected to benefit the most from the drug. 
 
 The two other categories are mild forms of the disease with one of them, known as mild obesity-related diabetes, linked to high BMI and the other, mild age-related diabetes, generally seen in older patients. The team say both categories can be managed with metformin and lifestyle advice. 
 
 
 
 “Diabetes is not the grey mass we have been calling type 2 – there are really subsets of the disease that require different treatment,” said Groop. 
 
 The categories were discovered by considering six different metrics, including a measure of blood glucose control, age at diagnosis, BMI, the presence of certain antibodies linked to autoimmune diabetes, and a measure of insulin sensitivity. 
 
 Genetic analysis revealed that all five subgroups are genetically distinct. Researchers say the groupings held both for those with newly diagnosed diabetes and those who had long had the disease, further suggesting the five categories are not simply down to different stages of the same form of diabetes – although further work is needed to explore whether patients can move between the types. It is also not clear if the different classifications have different causes. 
 
 Dr Emily Burns, head of research communications at Diabetes UK said finding diabetes subtypes could help patients, but that more work was needed. 
 
 “This research takes a promising step toward breaking down type 2 diabetes in more detail, but we still need to know more about these subtypes before we can understand what this means for people living with the condition,” she said. “For example, whether we’d find the same subtypes in people of different ethnicity or nationality.” 

 Background 
 
 Diabetes is presently classified into two main forms, type 1 and type 2 diabetes, but type 2 diabetes in particular is highly heterogeneous. A refined classification could provide a powerful tool to individualise treatment regimens and identify individuals with increased risk of complications at diagnosis. 
 
 Methods 
 
 We did data-driven cluster analysis (k-means and hierarchical clustering) in patients with newly diagnosed diabetes (n=8980) from the Swedish All New Diabetics in Scania cohort. Clusters were based on six variables (glutamate decarboxylase antibodies, age at diagnosis, BMI, HbA 1c , and homoeostatic model assessment 2 estimates of β-cell function and insulin resistance), and were related to prospective data from patient records on development of complications and prescription of medication. Replication was done in three independent cohorts: the Scania Diabetes Registry (n=1466), All New Diabetics in Uppsala (n=844), and Diabetes Registry Vaasa (n=3485). Cox regression and logistic regression were used to compare time to medication, time to reaching the treatment goal, and risk of diabetic complications and genetic associations. 
 
 Findings 
 
 We identified five replicable clusters of patients with diabetes, which had significantly different patient characteristics and risk of diabetic complications. In particular, individuals in cluster 3 (most resistant to insulin) had significantly higher risk of diabetic kidney disease than individuals in clusters 4 and 5, but had been prescribed similar diabetes treatment. Cluster 2 (insulin deficient) had the highest risk of retinopathy. In support of the clustering, genetic associations in the clusters differed from those seen in traditional type 2 diabetes. 
 
 Interpretation 
 
 We stratified patients into five subgroups with differing disease progression and risk of diabetic complications. This new substratification might eventually help to tailor and target early treatment to patients who would benefit most, thereby representing a first step towards precision medicine in diabetes. 
 
 Funding 
 
 Swedish Research Council, European Research Council, Vinnova, Academy of Finland, Novo Nordisk Foundation, Scania University Hospital, Sigrid Juselius Foundation, Innovative Medicines Initiative 2 Joint Undertaking, Vasa Hospital district, Jakobstadsnejden Heart Foundation, Folkhälsan Research Foundation, Ollqvist Foundation, and Swedish Foundation for Strategic Research.
– More than 30 million Americans have diabetes, but a study published Thursday in the Lancet Diabetes & Endocrinology concludes we've been thinking about the disease all wrong. The BBC reports diabetes is typically separated into type 1—an immune system disease—and type 2—mostly seen as the result of an unhealthy lifestyle. About 90% to 95% of diabetics are classified as type 2, according to Medical News Today. But: “Diabetes is not the grey mass we have been calling type 2," researcher Leif Groop tells the Guardian. "There are really subsets of the disease that require different treatment." Groop's team studied 14,775 diabetics and determined diabetes should actually be broken into five "genetically distinct" clusters. They are: Cluster 1: Severe autoimmune diabetes. Essentially the same as type 1. Cluster 2: Severe insulin-deficient diabetes. As in cluster 1, strikes young and healthy people, but the immune system isn't at fault. Cluster 3: Severe insulin-resistant diabetes. Bodies of largely overweight people no longer respond to insulin being produced. Cluster 4: Mild obesity-related diabetes. Patients are very overweight but have metabolisms closer to normal than patients in cluster 3. Cluster 5: Mild age-related diabetes. Mild form of diabetes developed by older people. The most common cluster. Each cluster has different risks associated with it, and patients could respond better to different treatments, researchers say. "I think it will mean a more individualized therapy [and] a better quality of life,” Groop says. (A study found moderate drinking may lower the risk of diabetes.)