Blood sugar and BP control preserves cognitive function in type 1 diabetes: Lancet
USA: With aging, cognitive function declines in people with type 1 diabetes (T1D), show results from 32 years of follow-up of the DCCT and EDIC Study.
"The association of blood sugar and blood pressure levels with cognitive decline suggests that their better management might be helpful for preserving cognitive function," the researchers wrote in The Lancet Diabetes & Endocrinology.
People with type 1 diabetes are living longer with advances in the treatment but there is not much information on the effect of T1D on cognitive ability as they become older adults. To fill this knowledge gap, Prof Alan M Jacobson, NYU Long Island School of Medicine, Mineola, NY, USA, and colleagues followed people with type 1 diabetes to identify risk factors for cognitive decline as they age.
The study included 1051 participants with type 1 diabetes enrolled in the Diabetes Control and Complications Trial (DCCT) and its follow-up Epidemiology of Diabetes Interventions and Complications (EDIC) study. They were assessed for cognitive parameters at baseline (median age 27 years) and 2, 5, 18, and 32 years later (median age 59).
The researchers repeatedly assessed HbA1c levels, frequency of severe hypoglycemia, non-glycemic risk factors such as elevated blood pressure, and microvascular and macrovascular complications. They also assessed the effects of these on measures of memory and psychomotor and mental efficiency.
Key findings of the study include:
· Over 32 years of follow-up, the researchers found substantive declines in memory and psychomotor and mental efficiency.
· Between 18 and 32 years of follow-up, the decline in psychomotor and mental efficiency was five times larger than the change from baseline to year 18.
· Independent of the other risk factors and comorbidities, exposure to higher HbA1c levels, more episodes of severe hypoglycaemia, and elevated systolic blood pressure were associated with greater decrements in psychomotor and mental efficiency that was most notable by year 32.
· The combined effect of the presence of these three risk factors is the equivalent to an additional 9·4 years of age.
"Our findings show that cognitive function declines with ageing in type 1 diabetes," concluded the authors. "The association of glycaemia and blood pressure levels with cognitive decline suggests that better management might preserve cognitive function."
The study titled, "Cognitive performance declines in older adults with type 1 diabetes: results from 32 years of follow-up in the DCCT and EDIC Study" is published in the journal Lancet Diabetes & Endocrinology.