@article{discovery10083145, note = {This version is the author accepted manuscript. For information on re-use, please refer to the publisher's terms and conditions.}, month = {November}, pages = {838--844}, journal = {Age and Ageing}, volume = {48}, year = {2019}, title = {Higher dementia incidence in older adults with type 2 diabetes and large reduction in HbA1c}, number = {6}, url = {https://doi.org/10.1093/ageing/afz108}, author = {Lee, ATC and Richards, M and Chan, WC and Chiu, HFK and Lee, RSY and Lam, LCW}, abstract = {BACKGROUND: although type 2 diabetes increases risk of dementia by 2-fold, whether optimizing glycemic level in late life can reduce risk of dementia remains uncertain. We examined if achieving the glycemic goal recommended by the American Diabetes Association (ADA) within a year was associated with lower risk of dementia in 6 years. METHODS: in this population-based observational study, we examined 2246 community-living dementia-free Chinese older adults with type 2 diabetes who attended the Elderly Health Centres in Hong Kong at baseline and followed their HbA1c level and cognitive status for 6 years. In line with the ADA recommendation, we defined the glycemic goal as HbA1c {\ensuremath{<}} 7.5\%. The study outcome was incident dementia in 6 years, diagnosed according to the 10th revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-10) or Clinical Dementia Rating of 1-3. RESULTS: those with HbA1c {$\ge$} 7.5\% at baseline and HbA1c {\ensuremath{<}} 7.5\% in 1 year were associated with higher rather than lower incidence of dementia, independent of severe hypoglycemia, glycemic variability and other health factors. Sensitivity analyses showed that a relative reduction of {$\ge$}10\%, but not 5-10\%, in HbA1c within a year was associated with higher incidence of dementia in those with high ({$\ge$}8\%) and moderate (6.5-7.9\%) HbA1c at baseline. CONCLUSION: a large reduction in HbA1c could be a potential predictor and possibly a risk factor for dementia in older adults with type 2 diabetes. Our findings suggest that optimizing or intensifying glycemic control in this population requires caution.}, keywords = {dementia, glycemic changes, older adults, type 2 diabetes}, issn = {1468-2834} }