Glycaemic control and sepsis risk in adults with type 1 diabetes.

Aims: To study the association between glycated haemoglobin (HbA1c) and sepsis in adults with type 1 diabetes, and to explore the relationship between HbA1c and mortality among individuals who developed sepsis.

Materials And Methods: We included 33 549 adult individuals with type 1 diabetes recorded in the Swedish National Diabetes Register between January 2005 and December 2015. We used multivariable Cox regression and restricted cubic spline analyses to study the relationship between HbA1c values and sepsis occurrence and association between HbA1c and mortality among those with sepsis.

Results: In total, 713 (2.1%) individuals developed sepsis during the study period. Compared with the HbA1c reference interval of 48-52 mmol/mol (6.5-6.9%), the adjusted hazard ratio for sepsis was: 2.50 [95% confidence interval (CI) 1.18-5.29] for HbA1c <43 mmol/mol; 1.88 (95% CI 0.96-3.67) for HbA1c 43-47 mmol/mol; 1.78 (95% CI 1.09-2.89) for HbA1c 53-62 mmol/mol; 1.86 (95% CI 1.14-3.03) for HbA1c 63-72 mmol/mol; 3.15 (95% CI 1.91-5.19) for HbA1c 73-82 mmol/mol; and 4.26 (95% CI 2.53-7.16) for HbA1c >82 mmol/mol. On multivariable restricted cubic spline analysis, we found a J-shaped association between HbA1c and sepsis risk, with the lowest risk observed at HbA1c of approximately 53 mmol/mol. We found no association between HbA1c and mortality among those individuals who developed sepsis.

Conclusions: In our nationwide observational study of adult individuals with type 1 diabetes we found a J-shaped relationship between HbA1c and risk of sepsis, with the lowest risk at HbA1c levels about 53 mmol/mol (7.0%). HbA1c was not associated with mortality in individuals affected by sepsis.