Intensive diabetes treatment reduces CVD risk even with excessive weight gain
medwireNews: Intensive treatment of type 1 diabetes appears to reduce the risk for cardiovascular disease (CVD) events even in those who gain excessive weight, but improved management of cardiovascular risk factors and revascularization may be needed.
During an average 6.5 years of the DCCT and an average 20 years of the EDIC follow-up study, 133 CVD events occurred in 12% of 604 patients receiving intensive treatment (glycemic levels as close to the nondiabetic range as possible), and 171 occurred in 14% of 609 patients receiving conventional treatment.
Excessive weight gain was seen in 151 patients in the intensive treatment group and 152 in the conventional treatment group, but the proportion of weight gain between minimal and excessive groups was greater for those receiving intensive versus conventional treatment, with a BMI of approximately 6 versus 3 kg/m2.
Despite this, there was only a small difference in major and total CVD event rates among patients with excessive versus minimal weight gain in either treatment group.
In the intensive treatment group, there were 40 CVD events among 15% of patients with excessive weight gain and 93 events among 11% of patients with minimal weight gain, giving an unadjusted, nonsignificant hazard ratio (HR) of 1.35. Among patients receiving conventional treatment, there were 64 events in 15% of patients who gained excessive weight and 107 events among 14% of patients who gained minimal weight, at an unadjusted HR of 1.06.
The researchers, led by Jonathan Purnell (Oregon Health & Science University, Portland, USA), note, however, that at about year 14 of the EDIC follow-up study, total CVD event rate curves began to diverge, with higher rates among patients receiving intensive treatment who gained excessive compared with minimal weight.
This meant that “by EDIC year 20 the incident rate of total CVD events in the excessive weight gain group treated intensively approximated that of the [conventional treatment] group,” they comment in Diabetes Care.
Purnell and colleagues suggest that the delayed divergence in total CVD events may be due to a greater use of medications to manage cardiovascular risk factors among the patients who gained excessive weight in the first 10 to 15 years of follow-up, noting that this group had more CVD risk factors at the DCCT closeout visit than patients with minimal weight gain.
Indeed, after adjusting for weight-related risk factors such as blood pressure, cholesterol, triglyceride levels, and medications to manage these factors, the HR between excessive and minimal weight gain was nearly completely attenuated, decreasing from 1.35 to 1.02.
But after EDIC year 14, the attenuation effect for CVD risk factors and medication was “somewhat reduced;” the HR still became nonsignificant but fell from only 1.99 to 1.57.
There was no divergence in rates of major adverse cardiovascular events (MACE) specifically at year 14, however, which the team suggests could be due to a “preventive” effect of revascularization as intensive treatment patients who gained excessive weight had a rate nearly twice that of patients with minimal weight gain.
“Further follow-up of this well-characterized population with type 1 diabetes will determine whether excessive weight gain with [intensive treatment] eventually results in increased (‘breakthrough’) MACE.”
By Lucy Piper
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