Background: Diabetic patients are at a higher risk of stroke than non-diabetic patients. However, the consensus of the effect of diabetes on stroke prognosis is still ongoing.
Aims: This study aims to investigate whether diabetes influences the type, treatment and mortality outcomes in stroke patients in Scotland using the Scottish Stroke Care Audit.
Methods: The Scottish Stroke Care Audit was used to identify 58,099 stroke cases in Scotland from January 2005 to December 2013. Baseline characteristics, stroke subtypes, six simple variable (SSV) assessment scores, acute treatment and mortality outcomes were examined in persons with and without a corresponding diabetes diagnosis in hospital coding. Statistical tests were used to compare these characteristics in the two groups, with logistic regression and cox-proportional hazards to evaluate the odds ratios and hazard ratios for mortality outcomes up to one year after first time stroke event.
Results: The Scottish Stroke Care Audit stroke population included 6119 (10.5%) with a hospital based code of diabetes. These patients had significantly more ischaemic strokes and less haemorrhagic strokes than non-diabetic patients (P < 0.0001), they also had better SSV scores indicating less severe strokes. Diabetic patients were less likely to receive thrombolysis for ischaemic stroke (P = 0.001), but were more likely to be given aspirin (P < 0.0001), with both groups treated similarly with antiplatelet therapy in-hospital (P = 0.566), and anticoagulant therapy upon discharge (P = 0.247). Less diabetic patients died up to 9 months after stroke, but at one year the mortality cases were similar in both groups (P = 0.061). Diabetes was not an independent risk factor for mortality, but when the cox proportional hazard model was adjusted for age, gender, stroke subtype and SSVs, the mortality risk increased in diabetics with HR 1.06 (95% CI: 1.01 - 1.12, p = 0.018)
Conclusions: Diabetes impacts on the type, treatment and mortality outcomes in stroke patients in Scotland, with a predisposition for milder ischaemic strokes in this group. As diabetes increases the risk of recurrent strokes, improving treatment of even mild events may reduce disease burden longer term.