Type 1 diabetes duration of about 20 years, independent of patient age, appears to be a threshold for cardiovascular disease, according to data from the Australian National Diabetes Audit.

“Odds of cardiovascular risk were low and static until approximately 20 years duration, at which point a positive linear association emerged,” the study said.

The analysis included more than 1,000 adults with type 1 diabetes presenting to one of 49 centres around Australia during one month in 2015.

It confirmed a high prevalence of cardiovascular risk factors notably dyslipidaemia (89%), HbA1c > 7.0% (81%), overweight or obesity (56%), a history of smoking (38.5%), albuminuria (31%) and hypertension (22%).

Increasing age, diabetes duration ≥ 20 years and smoking status and prescriptions of antihypertensive therapy were all positively associated with cardiovascular disease.

The findings suggested that cardiovascular risk stratification among patients with type 1 diabetes may not differ much from other high-risk populations – aside from the need to consider diabetes duration.

“The substantive population attributable risk (PAR) related to longer diabetes duration strongly supports the assessment and management of cardiovascular risk among people with long diabetes duration irrespective of their current age and the older age thresholds recommended by current CVD guidelines,” the study said.

The audit’s findings also reinforced the ongoing need for prioritisation of blood pressure control, routine screening for renal dysfunction, and support for smoking cessation in diabetes centres.

Dr Anthony Pease, a clinical fellow in the Endocrinology and Diabetes unit at Monash Health, told the limbic endocrinologists should continue to target traditionally considered risk factors.

However it could not be assumed patients with type 1 diabetes have the same risk as those with type 2 diabetes or people without diabetes.

“The problem is that there is no standard approach to cardiovascular risk stratification for patients with type 1 diabetes despite their vulnerability. From a broad perspective there needs to be further development, implementation and assessment of cardiovascular risk prediction models for people with type 1 diabetes as well as studies focussing on different interventional strategies in this population.”