Achieved levels of HbA1c and likelihood of hospital admission in people with type 1 diabetes in the Scottish population: a study from the Scottish Diabetes Research Network Epidemiology Group

<p>OBJECTIVE People with type 1 diabetes have increased risk of hospital admission compared with those without diabetes. We hypothesized that HbA1c would be an important indicator of risk of hospital admission.</p> <p>RESEARCH DESIGN AND METHODS The Scottish Care Information–Diabetes Collaboration, a dynamic national register of diagnosed cases of diabetes in Scotland, was linked to national data on admissions. We identified 24,750 people with type 1 diabetes during January 2005 to December 2007. We assessed the relationship between deciles of mean HbA1c and hospital admissions in people with type 1 diabetes adjusting for patient characteristics.</p> <p>RESULTS There were 3,229 hospital admissions. Of the admissions, 8.1% of people had mean HbA1c <7.0% (53 mmol/mol) and 16.3% had HbA1c <7.5% (58 mmol/mol). The lowest odds of admission were associated with HbA1c 7.7–8.7% (61–72 mmol/mol). When compared with this decile, a J-shaped relationship existed between HbA1c and admission. The highest HbA1c decile (10.8–18.4%/95–178 mmol/mol) showed significantly higher odds ratio (95% CI) for any admission (2.80, 2.51–3.12); the lowest HbA1c decile (4.4–7.1%/25–54 mmol/mol) showed an increase in odds of admission of 1.29 (1.10–1.51). The highest HbA1c decile experienced significantly higher odds of diabetes-related (3.31, 2.94–3.72) and diabetes ketoacidosis admissions (10.18, 7.96–13.01).</p> <p>CONCLUSIONS People with type 1 diabetes with highest and lowest mean HbA1c values were associated with increased odds of admission. People with high HbA1c (>10.8%/95 mmol/mol) were at particularly high risk. There is the need to develop effective interventions to reduce this risk.</p&gt