Introduction: Self-management influences diabetes outcomes and nocturnal glycaemia can be problematic in Type 1 diabetes (T1D).
Aims: To 1) explore adult T1D patient behaviour re overnight glycaemia by 2) developing/using a survey, and 3) describe patient characteristics related to optimal overnight glucose management.
Methods: RNS and SVH Diabetes Clinic T1D patients completed a (10-15 minute, in-clinic paper) questionnaire, including response to six suggested pre-bedtime blood glucose (4-20mmol/l) scenarios. Descriptive analyses, t-tests, Chi-square-tests, ANOVA and logistic regression were performed and significance taken at p<0.05.
Results: Over 90% eligible adults participated, n=205. Mean(SD) age and T1D duration were 41(17) and 20(16) years, with 38% using insulin pumps. Mean(SD) HbA1c was 7.6(1.1)% and 21% had had 1 severe hypoglycaemia in the last year. Mean(SD) blood glucose targets overnight, bedtime and daytime were 7.1(1.3), 7.5(1.4) and 6.7(1.0)mmol/l respectively. Mean(SD) blood glucose tests/day were 5.4(2.7), with 73% testing regularly at bedtime; 9% testing overnight daily, and 7% and 27% never testing pre-bed and overnight respectively. Most (68%) subjects treated a nocturnal hypo with rapid-acting carbohydrate only and only 44% retested glucose soon after. Thirty-one percent did not have ketone test-strips.
Only 28% made safe choices in all bedtime glucose scenarios. Optimal behaviour was associated with: (i) pump use (68% less, p=0.0005); (ii) frequent glucose testing (tests/day, at bedtime/week, overnight testing) lowered odds for suboptimal behaviour by 15%, 14% and 63% respectively (all p<0.05); and (iii) 1mmol/l lower bedtime glucose target (44% less, p=0.008). Suboptimal behaviour was 3.5-fold higher in those not retesting glucose till morning after a nocturnal hypo, p=0.0002. After extra exercise, alcohol or illness 48%, 46% and 47% (respectively), would not change their overnight care-plan. Thirty-two percent desired education.
Conclusion: Most T1D adults have behaviours placing them at risk of suboptimal overnight glycaemia. A survey, such as used herein, may identify at-risk patients.