An estimated 8.4 million people were living with the condition worldwide last year, according to study results published September 13 in the Lancet Diabetes & Endocrinology. Another 3.7 million people would have been alive last year if type 1 diabetes hadn’t prematurely ended their lives, the study also found. The study results suggest that this disease — which used to be called juvenile diabetes — is no longer predominantly a childhood condition. Half the new cases diagnosed last year were found in people older than 39. And far more new cases got diagnosed in adults — 316,000 — than in children and adolescents — 194,000. This suggests that long-standing treatment programs need to change to accommodate adults, says a coauthor of the study, Dianna Magliano, PhD, of the School of Public Health and Preventive Medicine at Monash University in Melbourne, Australia. “Such programs, in countries where they exist, are almost exclusively designed and delivered for children and youth with type 1 diabetes,” Dr. Magliano says. “In addition, our findings emphasize the urgent need for enhanced surveillance and data collection on type 1 diabetes incidence, prevalence, and mortality in adult populations — an area where data are especially scarce.” Type 1 diabetes is an autoimmune condition that develops when the body can’t make enough of the hormone insulin to keep glucose, or sugars, in the blood at a consistently healthy level. It can’t be prevented. People with type 1 diabetes need to monitor their blood sugar levels throughout the day and inject insulin to help maintain glucose levels in a healthy range. It’s far less common than type 2 diabetes, which is associated with obesity and aging and can often be prevented by maintaining a healthy body weight. When people have type 2 diabetes, the body stops using insulin efficiently enough to manage blood sugar, causing it to rise, a condition known as insulin resistance. For the new study, researchers used a mathematical model to examine global trends in type 1 diabetes based on data from children, adolescents, and adults in 97 countries. They used incidence data over time from 65 countries as well as mortality data from 37 countries to estimate both the current number of cases and deaths and to project trends through 2040. Ten countries with the highest prevalence of type 1 diabetes account for 60 percent of cases worldwide, the analysis found. These include: the United States, India, Brazil, China, Germany, Russia, Canada, Saudi Arabia, Spain, and the United Kingdom. One in five people living with type 1 diabetes resides in a low-income or middle-income country, the study also found. When researchers looked at mortality data, they found that 20 percent of fatalities from type 1 diabetes were due to cases going undiagnosed. Many of these cases were in sub-Saharan Africa and South Asia. “There is an opportunity to save millions of lives in the coming decades by raising the standard of care for type 1 diabetes — including ensuring universal access to insulin and other essential supplies — and increasing awareness of the signs and symptoms of type 1 diabetes to enable a 100 percent rate of diagnosis in all countries,” says the study’s senior author, Graham Ogle, MBBS, of the University of Sydney in Australia. People can live for years without noticing any symptoms of type 1 diabetes, according to the U.S. Centers for Disease Control and Prevention (CDC). Some symptoms are similar to type 2 diabetes, including frequent urination and thirstiness, fatigue, and numb or tingling hands and feet. With type 1 diabetes, some people may also experience nausea, vomiting, or stomach pains. The authors acknowledge some limitations of this study, including a lack of data to input into the model. Data is more limited for adult populations, in low- and moderate-income countries, and before 1975. Information obtained through extrapolation from nearby countries may be less accurate depending on genetic and environmental factors. In addition, estimates of rates of death from nondiagnosis are based on clinician impressions and are likely to be higher or lower than the actual situation. For mortality rates in diagnosed cases, information is scarce before 1980.