TY - JOUR
T1 - Glycaemic (HbA1c) variability and mortality in older people (age ≥70 years) with diabetes mellitus
T2 - a retrospective cohort study
AU - Forbes, Angus
AU - Murrells, Trevor
AU - Mulnier, Henrietta
AU - Sinclair, Alan J.
PY - 2018/1/20
Y1 - 2018/1/20
N2 - Background: Glycaemic targets for older people have been revised in recent years over concern that more stringent levels are associated with elevated mortality hazard. In this study, we explore this association considering glycaemic control and variability.
Methods: A 5 year retrospective cohort study using a large primary care dataset examining glycaemic control and variability exposures on all-cause mortality. The cohort comprised 54,803 patients with Type 1 and 2 diabetes aged ≥70 years, mean age 78.3(SD5·7) and 51% were female. Glycaemic control(HbA1c) was assessed in three models using: a baseline mean; whole follow-up period mean; and time-varying yearly updated mean. Glycaemic variation was assessed using an instability metric based on number of changes in HbA1c≥0·5%(5·5mmol/mol), scored low to high,0-100.
Findings: There were 17,680 deaths during the observation period, the mortality rate was 77 per 1000 person years. The data showed a 'J' shaped distribution for mortality hazard with significant elevations with HbA1c values >8% (64mmol/mol) and <6% (42mmol/mol). Survival diminished markedly with increasing instability in all models. For the whole period HbA1c measure the hazard ratios in patients with the highest instability metric(>80-100) (n=1,227) were 2·47 for females and 2·21 for males. Fitting the glycaemic control models with the instability metric softened the hazard distribution with significant hazard only being observed with HbA1c values >10%(86mmol/mol) in males and >9·5%(80mmol/mol) in females.
Interpretation: The data suggests that glycaemic variability may be an important factor in understanding mortality hazard in older people with diabetes.
AB - Background: Glycaemic targets for older people have been revised in recent years over concern that more stringent levels are associated with elevated mortality hazard. In this study, we explore this association considering glycaemic control and variability.
Methods: A 5 year retrospective cohort study using a large primary care dataset examining glycaemic control and variability exposures on all-cause mortality. The cohort comprised 54,803 patients with Type 1 and 2 diabetes aged ≥70 years, mean age 78.3(SD5·7) and 51% were female. Glycaemic control(HbA1c) was assessed in three models using: a baseline mean; whole follow-up period mean; and time-varying yearly updated mean. Glycaemic variation was assessed using an instability metric based on number of changes in HbA1c≥0·5%(5·5mmol/mol), scored low to high,0-100.
Findings: There were 17,680 deaths during the observation period, the mortality rate was 77 per 1000 person years. The data showed a 'J' shaped distribution for mortality hazard with significant elevations with HbA1c values >8% (64mmol/mol) and <6% (42mmol/mol). Survival diminished markedly with increasing instability in all models. For the whole period HbA1c measure the hazard ratios in patients with the highest instability metric(>80-100) (n=1,227) were 2·47 for females and 2·21 for males. Fitting the glycaemic control models with the instability metric softened the hazard distribution with significant hazard only being observed with HbA1c values >10%(86mmol/mol) in males and >9·5%(80mmol/mol) in females.
Interpretation: The data suggests that glycaemic variability may be an important factor in understanding mortality hazard in older people with diabetes.
M3 - Article
SN - 2213-8587
JO - The Lancet Diabetes and Endocrinology
JF - The Lancet Diabetes and Endocrinology
ER -
