Allen T C Lee1, Marcus Richards2, Wai C Chan3, Helen F K Chiu1, Ruby S Y Lee4, Linda C W Lam1. 1. Department of Psychiatry, The Chinese University of Hong Kong, Hong Kong SAR, China. 2. MRC Unit for Lifelong Health and Ageing at UCL, London, UK. 3. Department of Psychiatry, The University of Hong Kong, Hong Kong SAR, China. 4. Department of Health, Elderly Health Service, The Government of Hong Kong SAR, Hong Kong SAR, China.
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 < 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 ≥ 7.5% at baseline and HbA1c < 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 ≥10%, but not 5-10%, in HbA1c within a year was associated with higher incidence of dementia in those with high (≥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.
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 < 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 ≥ 7.5% at baseline and HbA1c < 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 ≥10%, but not 5-10%, in HbA1c within a year was associated with higher incidence of dementia in those with high (≥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.
Authors: Danielle Newby; Andrew Brent Linden; Marco Fernandes; Yasmina Molero; Laura Winchester; William Sproviero; Upamanyu Ghose; Qingqin S Li; Lenore J Launer; Cornelia M van Duijn; Alejo J Nevado-Holgado Journal: BMJ Open Diabetes Res Care Date: 2022-09