Clinical practice guidelines recommend screening for diabetes after the age of 45 years, but without an upper age limit. An ageing population has resulted in increasing numbers of older people being diagnosed. Previous reports indicate a J-shaped relationship between HbA1c and mortality in older populations with largely longstanding diabetes. However, whether these mortality relationships hold true in the newly diagnosed elderly remains uncertain, as do appropriate glycaemic targets. We aimed to study the relationship between HbA1c and mortality in newly diagnosed elderly aged ≥ 75 years. Records from the RPA Diabetes Clinical Database from 1988 to 2015, linked with the Australian National Death Index to establish all cause, IHD and cancer mortality outcomes were examined. 376 subjects were studied; median diabetes duration at first visit was 0.8 years (IQR 0.2-2.4), with mean age at diagnosis 78.7±3.1 years, 48% male and 53% Angloceltic. Data were stratified by updated HbA1c% NGSP Units categories (< 6; 6.1-7.0; 7.1-8.0; 8.1-9.0 and >9) with a median of 1.8±1.5 measures. Over a median observation period of 6.0 (IQR 2.8-10.4) years there were 237 deaths (17% from cancer, 38.9% from IHD). Using Kaplan-Meier survival analysis for all-cause mortality, no differences in survival between the HbA1c categories were seen (logrank p=0.8). Cox regression was used to examine the relationship between all-cause mortality and updated HbA1c categories after accounting for age or duration at first visit, gender and ethnicity. No significant differences nor observable trends in RR were seen using the HbA1c 6.1-7% group as reference. Prior albuminuria, stroke history and lipid status also had no impact on this relationship. Examination of IHD and cancer-related deaths similarly showed no relationship with HbA1c in this population. Whilst current guidelines recommend a general HbA1c target of 7% to 8% in the elderly we did not demonstrate a survival benefit for any HbA1c level in these newly diagnosed over 75 years of age.
M. McGill: None. L.M. Molyneaux: None. M.I. Constantino: None. S.M. Twigg: Advisory Panel; Self; Abbott, Boehringer Ingelheim Pharmaceuticals, Inc., Novo Nordisk Inc., Sanofi-Aventis. Board Member; Self; AstraZeneca. Research Support; Self; Abbott. Speaker's Bureau; Self; Abbott, AstraZeneca, Merck Sharp & Dohme Corp., Novo Nordisk Inc., Sanofi-Aventis. T. Middleton: Other Relationship; Self; AstraZeneca. T. Wu: Advisory Panel; Self; Boehringer Ingelheim International GmbH, Eli Lilly and Company, Novo Nordisk A/S, Sanofi. Speaker's Bureau; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Eli Lilly and Company, Merck Sharp & Dohme Corp., Novo Nordisk A/S, Sanofi. J. Wong: Advisory Panel; Self; Sanofi. Speaker's Bureau; Self; AstraZeneca, Lilly Diabetes.