Prospective study of the association between depressive symptoms at type 2 diabetes diagnosis and time to insulin initiation in the South London diabetes (SOUL-D) cohort.

AIMS

Initiation of insulin is usually delayed even when required. We aim to estimate the association between depressive symptoms on time to become insulin requiring and time to insulin initiation.

METHODS

8-year follow-up of a cohort of newly diagnosed people with T2D recruited in south-east London, UK (2008-2012). Baseline depressive symptoms were assessed using the Patient Health Questionnaire-9. Time to insulin-requiring was defined when optimal glycaemic levels were not achieved (HbA1c >58 mmol/mol) at least three months after the 2nd oral antidiabetic was prescribed, and time to insulin initiation was defined as first insulin prescription.

RESULTS

Seventy percent (n = 1166) of the baseline cohort was followed up. Median time to insulin requiring was 84 months (IQR 63-100) and to insulin initiation 93 months (IQR 79-105). Participants with depressive symptoms at baseline required insulin earlier (mean [SD] 73.64 [32.16] vs. 79.05 [29.07] months, p = 0.007) and were prescribed insulin sooner (82.53 [30.19] vs. 89.72 [22.02] months, p < 0.001). In Cox regression, depressive symptoms at baseline were not associated with time to insulin requiring (HR [95 % CI]; 1.16 [0.86-1.57], p = 0.34) nor to insulin initiation (HR = 1.00 [0.99-1.00], p = 0.49).

CONCLUSIONS

Depressive symptoms were not associated with time to insulin requiring and initiation after adjusting for potential confounding.