According to the central finding of a new study to be published Tuesday in the medical journal Annals of Internal Medicine, millions of Americans with chronic disease like diabetes or high blood pressure are not getting adequate treatment because they are among the nation’s growing ranks of uninsured.

An estimated 11.4 million Americans with at least one chronic illness have no health insurance. Many of these people are doing without doctors’ visits or depending on emergency rooms for their medical care, the study said.

“These are people who, with modern therapies, can be kept out of trouble,” said Dr. Andrew P. Wilper, the study’s lead author. “Therapies for someone with diabetes and hypertension “are routine and widely available, if you have insurance,” said Dr. Wilper, a medical instructor at the University of Washington in Seattle.

“Primary care doctors know that people who don't have access to health care due to health insurance suffer,” Wilper said. “We wanted to study that issue and bring public attention to it.”

Wilper and his colleagues scrutinized data obtained from the National Health and Nutritional Examination Survey for 1999-2004, which included 12,486 men and women 18 to 64 years old. Based on this nationally representative sample, they came to the conclusion that 16.1 percent of people with heart disease, 15.5 percent of those with high blood pressure, and 16.6 percent of diabetics are uninsured.