Hypoglycemia is associated with dementia in elderly patients with type 2 diabetes mellitus: An analysis based on the Korea National Diabetes Program Cohort

Aim Although hypoglycemia is associated with cognitive dysfunction, including dementia, in patients with type 2 diabetes mellitus (DM), the data are equivocal. The purpose of this study was to investigate the association between hypoglycemia, dementia, and other cognitive dysfunctions. Methods This was a prospective observational study based upon the Korea National Diabetes Program (KNDP). Among the 4540 participants in the KNDP cohort, individuals aged ⩾60 years without any history of hypoglycemia or cognitive dysfunction (n = 1957) were included. Nationally representative data from the Health Insurance Review and Assessment Service of Korea claim database were used to obtain a more precise determination of patient outcome. Results During a mean follow-up period of 3.4 ± 0.9 years, 118 subjects experienced hypoglycemia-related events. The incidence of dementia and cognitive dysfunction was 7.5 cases per 1000 person-years (PY) and 0.61 cases per 1000 PY, respectively. In the subjects who experienced hypoglycemic events (relative to those who did not), the incidence of dementia was significantly higher (P = 0.0139), but the incidence of cognitive dysfunction was not (P = 0.1106). Hypoglycemic events were associated with dementia (HR, 2.689; 95% CI, 1.080–6.694, P = 0.0335) following multiple adjustments. There was also a significant linear trend toward an increased dementia risk commensurate with an increasing number of hypoglycemic events (P = 0.0286). Conclusions Hypoglycemia is significantly associated with the risk of dementia in Korean type 2 DM patients aged ⩾60 years.