Mean HbA1c, HbA1c variability, and mortality in people with diabetes aged 70 years and older: a retrospective cohort study

Publication date: Available online 16 April 2018 Source:The Lancet Diabetes & Endocrinology Author(s): Angus Forbes, Trevor Murrells, Henrietta Mulnier, Alan J Sinclair Background Glycaemic targets for older people have been revised in recent years because of concern that more stringent targets are associated with increased mortality. We aimed to investigate the association between glycaemic control (mean HbA1c) and variability (variability of HbA1c over time) and mortality in older people with diabetes. Methods We did a 5-year retrospective cohort study using The Health Improvement Network database, which includes data from 587 UK primary care practices. We included patients of either sex who were aged 70 years and older with type 1 or type 2 diabetes. The primary outcome was time to all-cause mortality. Our primary exposure variables were mean HbA1c and variability of HbA1c over time. The observation included a 4-year run-in period (from 2003) as a baseline, with a 5-year follow-up (from 2007 to 2012). We assessed mean HbA1c in three models: a baseline mean HbA1c for 2003–06 (model 1), the mean across the whole follow-up period (model 2), and a time-varying yearly updated mean (model 3). A variability score (from 0 [low] to 100 [high]) was calculated on the basis of number of changes in HbA1c of 0·5% (5·5 mmol/mol) or more from 2003 to 2012 or to the point of mortality, based on changes in the annual mean as per each model with a minimum of six readings. ...
Source: The Lancet Diabetes and Endocrinology - Category: Endocrinology Source Type: research