For patients with type 1 diabetes (T1D), initiating earlier, intensive glycemic control as safely as possible greatly reduced their future risk of cardiovascular and renal complications, compared with control efforts later in the disease, according to findings published in Diabetes Care.
Data were sourced from the Diabetes Control and Complications Trial (DCCT) conducted from 1983 to 1993 and the Epidemiology of Diabetes Interventions and Complications (EDIC) trial from 1994 to present day. Patients with T1D were assessed for long-term clinical outcomes based on earlier vs later glycemic control during the course of their disease.
The relationship between updated mean glycated hemoglobin (HbA1C) and cardiovascular disease (CVD) or reduced (<60 mL/min/1.73 m2) estimated glomerular filtration rate (eGFR) risk (used to assess kidney disease) was near-linear.
Risk for CVD over 20 years was 15.3% among individuals who had HbA1C of 9% during a cumulative 20-year follow-up period. For individuals who reduced their HbA1C to 7% during years 11-20, risk for CVD decreased to 12.4%. For individuals who maintained HbA1C at 7% over the entire 20 years, CVD risk was 7.7%. In the case in which HbA1C control was lost during the last 10 years, increasing from 7% to 9%, the cumulative CVD risk was 9.0%. These data indicated that earlier glycemic control was more effective at decreasing CVD risk.
A similar pattern was observed for reduced eGFR risk, in which individuals who had lower (7%) HbA1C during the first decade of the study had lower risk than those who had higher (9%) HbA1C. Specifically, risk was 4.9% for maintained low HbA1C; 6.9% for loss of glycemic control during the last decade; 14.5% for gaining glycemic control the last decade; and 18.1% for maintained high HbA1C.
Researchers further noted that, in the first few years of follow-up in the EDIC trial, HbA1c levels in the original two treatment groups converged, yet patients in the original DCCT group continued to have a reduced risk of further [diabetes-related] progression of complications for at least 10 years after the end of the DCCT [trial]. They attributed this to ‘metabolic memory’, which they said further supports early, intensive therapeutic intervention in people with type 1 diabetes.
Researchers acknowledged the study data may have been biased, as outcomes of the DDCT and EDIC trials have been shown to be strongly associated with updated mean HbA1C.
The study authors concluded that earlier metabolic control can substantially lower long-term clinical effects of CVD and renal complications risk, indicating that earlier intensive therapies may be effective for maintaining long-term health among patients with T1D.
Disclosure: Several industries provided free or discounted supplies to support participants’ adherence to study protocols. Please refer to the original article for a full list of disclosures.
Lachin JM, Bebu I, Nathan DM and the DCCT/EDIC Research Group. . The beneficial effects of earlier versus later implementation of intensive therapy in type 1 diabetes. Diabetes Care. 2021. Published online August 11, 2021. doi:10.2337/dc21-1331