GENEVA — The International Diabetes Federation predicts that at least one in 10 adults could have diabetes by 2030, according to its latest statistics.

In a report issued on Monday, the advocacy group estimated that 552 million people could have diabetes in two decades’ time based on factors like aging and demographic changes. Currently, the group says that about one adult in 13 has diabetes.

The figure includes both types of diabetes as well as cases that are undiagnosed. The group expects the number of cases to jump by 90 percent even in Africa, where infectious diseases have previously been the top killer. Without including the impact of increasing obesity, the International Diabetes Federation said its figures were conservative.

According to the World Health Organization, there are about 346 million people worldwide with diabetes, with more than 80 percent of deaths occurring in developing countries. The agency projects diabetes deaths will double by 2030 and said the International Diabetes Federation’s prediction was possible.

“It’s a credible figure,” said Gojka Roglic, head of WHO’s diabetes unit. “But whether or not it’s correct, we can’t say.”

Roglic said the projected future rise in diabetes cases was because of aging rather than the obesity epidemic. Most cases of diabetes are Type 2, the kind that mainly hits people in middle age, and is linked to weight gain and a sedentary lifestyle.

Roglic said a substantial number of future diabetes cases were preventable. “It’s worrying because these people will have an illness which is serious, debilitating, and shortens their lives,” she said. “But it doesn’t have to happen if we take the right interventions.”