Objective
<p>Current type 2 diabetes (T2D) management contraindicates intensive
glycemia treatment in patients with high cardiovascular disease (CVD) risk, and
is partially motivated by evidence of harms in the Action to Control
Cardiovascular Risk in Diabetes (ACCORD) trial. Heterogeneity in response to
intensive glycemia treatment has been observed, suggesting potential benefit for
some individuals.</p>
<p>Research Design and Methods</p>
<p>ACCORD was a randomized controlled trial that investigated whether
intensively treating glycemia in individuals with T2D reduced CVD outcomes.
Using a novel approach to cluster HbA1c trajectories, we identified groups in
the intensive glycemia arm with modified CVD risk. Genome-wide analysis and polygenic
score (PS) were developed to predict group membership. Mendelian randomization
was performed to infer causality. </p>
<p>Results</p>
<p>We identified four clinical groupings in the intensive glycemia arm, and
clinical group 4 (C4) displayed fewer CVD outcomes (HR=0.34, <i>P</i>=2.01x10<sup>-3</sup>) and
microvascular outcomes (HR=0.86, <i>P</i>=.015)
than standard treatment. A single nucleotide polymorphism, rs220721, in <i>MAS1, </i>reached suggestive significance<i> </i>with C4 (<i>P</i>=4.34x10<sup>-7</sup>). The PS predicted C4 with
high accuracy (AUC=0.98), and predicted C4 displayed reduced CVD risk on
intensive versus standard glycemia treatment (HR=0.53, <i>P</i>=4.02x10<sup>-6</sup>), but not for microvascular outcomes (<i>P</i><.05).
Mendelian randomization indicated causality between the PS, on-trial HbA1c, and
reduction in CVD outcomes (<i>P</i><.05). </p>
<p>Conclusions</p>
<p>We found evidence of a T2D clinical group in ACCORD that benefited from
intensive glycemia treatment, and membership of this group can be predicted
using genetic variants. This study generates new hypotheses with implications
for precision medicine in T2D and represents an important development for this
landmark clinical trial warranting further investigation.</p>