Spotlight on demographic trends in diabetes

Several recent studies analyzed different demographic trends related to diabetes.

An analysis in the March 30 Morbidity and Mortality Weekly Report (MMWR) used data from the 2016 National Health Interview Survey to estimate prevalence of diagnosed diabetes in the U.S. A total of 3,519 adult survey respondents reported having diabetes, for an overall crude prevalence of 9.44%. Type 1 diabetes comprised 5.8% of the cases and 90.9% were type 2, with the remainder being other types of diabetes. The authors then estimated that 1.3 million Americans have type 1, 21.0 million have type 2, and 0.8 million have another type of diabetes. Type 1 diabetes was more common among men than women and among non-Hispanic white people than Hispanic people. Type 2 diabetes was more common among black people (11.52%) than Asian people (6.89%), white people (7.99%), and Hispanic people (9.07%). Diagnosed type 2 diabetes prevalence estimates increased with age and decreased with higher levels of educational attainment.

In the same issue of MMWR, data from the Agency for Healthcare Research and Quality's National Inpatient Sample were used to calculate trends in diabetic ketoacidosis (DKA) hospitalizations. From 2000 to 2009, the age-adjusted rate of DKA hospitalizations fluctuated but declined at an average annual rate of 1.1%. However, from 2009 to 2014, the rate increased 54.9%, from 19.5 to 30.2 per 1,000 persons with diabetes. In the same period, in-hospital mortality from DKA declined consistently, from 1.1% in 2000 to 0.4% in 2014. The authors said the causes of these trends were not clear, but possible explanations include new medications with higher DKA risk, changes in case definitions, and lower thresholds for hospitalization (the latter two of which would also help explain the decrease in mortality).

Another study, published by Nutrition and Diabetes on March 13, used data on 9,826 adults from the National Health and Nutrition Examination Survey to assess the prevalence of obesity, metabolic syndrome, and diabetes. It found New England to have low rates of diabetes, metabolic syndrome, and obesity compared to other census divisions. The Mountain division also had low rates of obesity and the Pacific and Mid-Atlantic divisions had relatively low rates of metabolic syndrome. The East South Central and West North Central divisions had high rates of all three conditions. The authors analyzed the results by race and sex and observed that some of the geographic variation was due to rates among non-Hispanic white females who had a high prevalence of metabolic syndrome (>32%) in the Midwest and South and a low prevalence of metabolic syndrome (24%) in the West and Northeast. Geographic differences in metabolic syndrome imply different levels of risk for future cardiovascular disease and diabetes, with increased risk in the center of the United States.

“As opposed to prior reports which have suggested, for example, a stroke ‘belt’ in the United States from the South up through the Ohio River Valley, these data and others begin to portray an obesity and [metabolic syndrome] ‘zipper’ extending from the South up through the Midwest,” the authors said. They also noted that when the results were broken out by age group, adults ages 20 to 39 years showed smaller differences between regions, possibly indicating increases in future disease risk. The results should serve as “a reminder for vigilance toward surveillance and lifestyle modification,” the study said.