Abstract
BACKGROUND: Undiagnosed diabetes mellitus (UDM) is associated with poorer health outcomes compared to diagnosed DM. We investigated factors associated with UDM in a highly urbanized Chinese setting to facilitate UDM detection. METHODS: We analysed data from the cross-sectional Hong Kong Population Health Survey. We defined UDM by blood glucose and HbA1c levels and a negative history of self-reported doctor-diagnosed DM. We categorized diabetes status into UDM, incident DM (IDM, i.e. recently diagnosed) and individuals without diabetes and used multinomial logistic regression models to investigate the relationship between diabetes status and social and health service-related factors. RESULTS: We included 98 IDM cases, 101 UDM cases, and 2,153 individuals without diabetes. Individuals aged 35-44 years (aOR 12.65, 95% C.I. 2.54-62.97) and those living in subsidized-sale housing (aOR 2.01, 95% C.I. 1.14-3.56) had a higher risk of UDM relative to not having diabetes, but not IDM. Males who were economically active (aOR 4.22, 95% C.I. 1.25-14.30), and males who did not have regular check-ups (aOR 3.05, 95% C.I. 1.16-8.00) had higher risks of UDM relative to not having diabetes, whereas males with a higher household income had a lower risk of UDM (aOR 0.94, 95% C.I. 0.89-0.99). Compared to individuals without diabetes, UDM cases had comparable physical activity levels but most were work- and transport-related rather than recreational. CONCLUSIONS: Compared to individuals without diabetes or IDM cases, economically active males, males without regular check-ups and males with lower household income had a higher risk of UDM. Targeted active DM screening can reduce UDM. However, further research on the benefits of different types of physical activity is needed.