Undiagnosed diabetes is prevalent in younger adults and associated with a higher risk cardiometabolic profile compared to diagnosed diabetes

Background A substantial percentage of patients have undiagnosed diabetes. We investigated the demographic characteristics and cardiometabolic profiles of subjects with undiagnosed diabetes. Methods A cross-sectional study with nationally representative samples of 25 490 subjects aged ≥ 20 years from the KHNANES 2008 to 2011, which applied a complex, multistage, probability proportional to size sampling design. Subjects were categorized as having normal glucose (n = 16 880), impaired fasting glucose (n = 5771), undiagnosed diabetes (n = 713), or diagnosed diabetes (n = 2126). Hyper low-density lipoprotein cholesterolemia was individually evaluated by the 2004 Adult Treatment Panel III guidelines and predicted risk of cardiovascular disease was estimated from the Framingham model. Results Among overall subjects with diabetes, the prevalence of undiagnosed diabetes was markedly increased in younger adults compared to older adults (49% in diabetic subjects <50 years vs 23% in diabetic subjects ≥50 years, P <.001), suggesting significant discrepancies in age-based screening. Patients with undiagnosed diabetes were also more likely to have undiagnosed or uncontrolled hypertension and hyper-low-density lipoprotein cholesterolemia. Individuals with undiagnosed diabetes had a significantly higher predicted 10-year Framingham cardiovascular disease risk than those with diagnosed diabetes (11% vs 8% in <50 years, 33% vs 30% in ≥50 years; both P <.001). Patients with undiagnosed diabetes were also more likely to have multiple cardiovascular risk factors including obesity, smoking and uncontrolled hypertension. Conclusions People with undiagnosed diabetes have a higher predicted risk for cardiovascular disease compared to those with diagnosed diabetes. Intensive screening for diabetes in younger adults should be stressed in public healthcare to reduce the burden of modifiable cardiometabolic risk among individuals with undiagnosed diabetes.