Practice Update: Diabetes

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Glycemic Control Reduces Risk
of Coronary Events in MenWith
Type 1 Diabetes
Heart (British Cardiac Society)
Take-home message
• This Swedish, matched control cohort study evaluated the
association between major coronary events and glycemic
control and renal complications in patients with type 1 dia-
betes. The results revealed a significantly higher incidence
of cardiac events and death in patients with type 1 diabetes,
particularly in women and in those with poor glycemic con-
trol and more severe renal complications.
• The authors concluded that, although glycemic control
and improved renal function can reduce cardiac event risk
in men with type 1 diabetes, women with type 1 diabetes
remain at higher risk for cardiac events despite glycemic
control and renal function.
Abstract
OBJECTIVE The excess risk of major coronary events (acute myocardial
infarction (AMI) or death from coronary heart disease (CHD)) in individ-
uals with type 1 diabetes (T1D) in relation to glycaemic control and renal
complications is not known.
METHODS Individuals with T1D in the Swedish National Diabetes Registry
after 1 January 1998, without a previous MI (n=33170) and 164698 controls
matched on age, sex and county were followed with respect to non-fatal
AMI or death from CHD. Data were censored at death due to any cause
until 31 December 2011.
RESULTS During median follow-up of 8.3 and 8.9 years for individuals with
T1D and controls, respectively, 1500 (4.5%) and 1925 (1.2%), experienced
non-fatal AMI or died from CHD, adjusted HR 4.07 (95% CI 3.79 to 4.36).
This excess risk increased with younger age, female sex, worse glycae-
mic control and severity of renal complications. The adjusted HR in men
with T1D with updated mean haemoglobin A1c (HbA1c) <6.9% (52 mmol/
mol) and normoalbuminuria was 1.30 (95% CI 0.90 to 1.88) and in women
3.16 (95% CI 2.14 to 4.65). HRs increased to 10.7 (95% CI 8.0 to 14.3) and
31.8 (95% CI 23.6 to 42.8) in men and women, respectively, with HbA1c
>9.7%and renal complications.
CONCLUSIONS The excess risk of AMI in T1D is substantially lower with good
glycaemic control, absence of renal complications and men compared
with women. In women, the excess risk of AMI or CHD death persists even
among patients with good glycaemic control and no renal complications.
Glycaemic control and excess risk of major coronary events in persons
with type 1 diabetes. Heart 2017 Jul 14;[EPub Ahead of Print], V Matule-
viciene-Anängen, A Rosengren, AM Svensson, et al.
COMMENT
By Robert H Eckel MD
Well known for decades is the
increased risk of major coro-
nary heart disease (CHD) events
and related mortality in patients with type
1 diabetes (T1DM) and the added risk in
patients with renal disease. Examining
acute myocardial infarction (AMI) and CHD
death as the specific manifestations of
CHD, the paper by Matulevicien-Anängen
et al is the most recent example of obser-
vational data from the Swedish National
Diabetes Register (NDR) of what factors
contribute to risk for AMI/CHD death in
patients with T1DM.
In this report, hazard ratios (HR) for AMI/
CHD death were assessed in 33,170
T1DM patients and 164,698 controls,
well matched for age and gender, for up
to 13 years (median, 8.3 and 8.9 years,
respectively) and adjusted for multiple
variables except hypertension and smok-
ing (model 3). Age-dependent AMI/CHD
death was approximately four times more
common in T1DM than in controls, with HRs
similar in T1DMmen and women; however,
the marked increase in HR for women
with T1DM relates to the much lower inci-
dence in control women. Moreover, rates
increased in relationship to levels of gly-
cemia (HbA1c ≤6.9% in the 1st quintile
to ≥9.7% in the 5th quintile), proteinuria,
and estimated glomerular filtration rate.
Thus, what is new here? Unfortunately, not
much. First, how generalizable are these
data, and the relationship of proteinuria
and renal dysfunction to cardiovascular
disease events in T1DM is well recog-
nized, as is the importance of glycemia to
macrovascular complications, especially
in this cohort. Although the importance
of the trend in glycemia to events is con-
vincing, a question arises as to whether
this increased slope begins at levels of
HbA1c >6.9% or >7.8%, particularly for
women; and data for hypoglycemia were
not included. Overall, this matter becomes
quite relevant for clinical practice.
Dr Eckel is a Distinguished
Alumnus of the University of
Cincinnati College of
Medicine and the Charles A
Boettcher II Endowed Chair
in Atherosclerosis, and
Professor of Medicine,
Division of Endocrinology,
Metabolism and Diabetes and the Division of
Cardiology, and Professor of Physiology and
Biophysics, University of Colorado School of
Medicine Anschutz Medical Campus.
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