Prevalence of Undiagnosed Diabetes in 2004 and 2012: Evidence From the English Longitudinal Study of Aging

Background: In light of recent publicity campaigns to raise awareness of diabetes, we investigated changes in the prevalence of diabetes and undiagnosed diabetes in adults age 50 and older in England between 2004 and 2012, and explored risk factors for undiagnosed diabetes.

Method: In total, 7666 and 7729 individuals were from Wave 2 (2004-2005, mean age 66.6) and Wave 6 (2012-2013, mean age 67.6) of the English Longitudinal Study of Ageing. Diagnosed diabetes was defined as either self-reported diabetes or taking diabetic medications. Undiagnosed diabetes was defined as not self-reporting diabetes and not taking diabetic medications, but having a glycated hemoglobin measurement ≥48 mmol/mol (6.5%).

Results: There were increases in both diagnosed diabetes (7.7%-11.5%) and undiagnosed diabetes (2.4%-3.4%) between 2004 and 2012. However, a small decrease in the proportion of people with diabetes who were unaware of this condition (24.5%-23.1%, p < .05) was observed. Only men aged 50-74 showed a stable prevalence of undiagnosed diabetes, with better recognition of diabetes. Age, non-white ethnicity, manual social class, higher diastolic blood pressure, and cholesterol level were factors associated with higher risks of undiagnosed diabetes, whereas greater depressive symptoms were related to lower risks.

Conclusion: This study suggests that the greater awareness of diabetes in the population of England has not resulted in a decline in undiagnosed cases between 2004 and 2012. A greater focus on people from lower socioeconomic groups and those with cardiometabolic risk factors may help early diagnosis of diabetes for older adults.