Practice Update: Diabetes

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Higher Two-Hour Post-Load Glucose
Predicts Risk for Cardiovascular Events
in CAD
Diabetes Care
Take-home message
• The authors of this study sought to characterize the prognostic value of three
screening tools for diabetes—fasting glucose (FPG), 2-hour post-load glucose
(2h-PG) from an oral glucose tolerance test, and HbA1c—in a population of patients
with coronary artery disease (CAD). Researchers screened 4004 patients with CAD
and no history of diabetes with all three screening tools. After 2 years, 246 patients
(6.5%) experienced the primary outcome, a composite of cardiovascular mortality,
nonfatal myocardial infarction, stroke, and hospitalization for heart failure. The 2h-PG
test was the only screening tool that correlated with the primary outcome. Both a
HbA1c of 5.7% to 6.5% and a 2h-PG of 7.8 to 11.0 mmol/L independently predicted
the risk of diabetes during follow-up.
• The authors conclude that, in patients with CAD, 2h-PG can provide valuable
prognostic information on the risk of future cardiovascular events. In addition,
increases in HbA1c and 2h-PG can signal a greater risk for diabetes.
Abstract
OBJECTIVES Three tests are recommended for
identifying dysglycemia: fasting glucose (FPG),
2-h postload glucose (2h-PG) from an oral
glucose tolerance test (OGTT), and glycated
hemoglobin A1c (HbA1c). This study explored
the prognostic value of these screening tests
in patients with coronary artery disease (CAD).
RESEARCH DESIGN AND METHODS FPG, 2h-PG, and
HbA1c were used to screen 4,004 CAD patients
without a history of diabetes (age 18-80 years)
for dysglycemia. The prognostic value of these
tests was studied after 2 years of follow-up. The
primary end point included cardiovascular mor-
tality, nonfatal myocardial infarction, stroke, or
hospitalization for heart failure and a secondary
end point of incident diabetes.
RESULTS Complete information including all three
glycemic parameters was available in 3,775
patients (94.3%), of whom246 (6.5%) experienced
the primary end point. Neither FPG nor HbA1c pre-
dicted the primary outcome, whereas the 2h-PG,
dichotomized as <7.8 vs. ≥7.8mmol/L, was a signif-
icant predictor (hazard ratio 1.38, 95% CI 1.07-1.78;
P = 0.01). During follow-up, diabetes developed in
78 of the 2,609 patients (3.0%) without diabetes
at baseline. A FPG between 6.1 and 6.9 mmol/L
did not predict incident diabetes, whereas HbA1c
5.7-6.5% and 2h-PG 7.8-11.0mmol/L were both sig-
nificant independent predictors.
CONCLUSIONS The 2h-PG, in contrast to FPG and
HbA1c, provides significant prognostic informa-
tion regarding cardiovascular events in patients
with CAD. Furthermore, elevated 2h-PG and
HbA1c are significant prognostic indicators of
an increased risk of incident diabetes.
The prognostic value of fasting plasma glu-
cose, two-hour postload glucose, and HbA1c in
patients with coronary artery disease: a report
from EUROASPIRE IV: a Survey from the Euro-
pean Society of Cardiology Diabetes Care 2017
Jun 21;[EPub Ahead of Print], B Shahim, D De
Bacquer, G De Backer, et al.
COMMENT
By Antonio Ceriello MD, MPH
This study confirms, in a large cohort
of people with CAD and without
diabetes, the role of 2-hour glyce-
mia during an oral glucose tolerance test
(OGTT) as an independent risk factor for
a future cardiovascular event.
What can be the clinical impact of this new
evidence? Some epidemiological evi-
dence in the past led to the hypothesis
that postprandial glycemia (PPG) should
be considered an independent risk fac-
tor for CVD,1 but that OGTT could not be
considered equivalent to a meal. This con-
cern was overcome by the demonstration
of the existence of a direct correlation, at
any time, between the values of glycemia
during OGTT and those during standard
meals and home blood glucose monitor-
ing in individuals with or without impaired
glucose tolerance or overt diabetes.2
Furthermore, the San Luigi Gonzaga Dia-
betes Study confirmed, after a very long
follow-up of people with type 2 diabetes,
that 2-hour PPG is an independent pre-
dictor of CVD3—evidence more recently
confirmed.4 At the same time, results from
specific intervention trials are inconclu-
sive.5 In this respect, however, it should
be noted that perhaps no trial has yet
been well-designed specifically for this
purpose.6
Several, if not almost all, current guide-
lines suggest controlling PPG for the
optimal management of diabetes and its
complications; therefore, in my opinion,
this study is further stressing the need for
controlling PPG in people with diabetes to
reduce the risk of CVD.
References
1. Ceriello A, Hanefeld M, Leiter L, et al.
Postprandial glucose regulation and
diabetic complications. Arch Intern Med
2004;164(19):2090-2095.
2. Meier JJ, Baller B, Menge BA, et al. Excess
glycaemic excursions after an oral glucose
tolerance test compared with a mixed meal
challenge and self-measured home glucose
profiles: is the OGTT a valid predictor of
postprandial hyperglycaemia and vice versa?
Diabetes Obes Metab 2009;11(3):213-222.
3. Cavalot F, Pagliarino A, Valle M, et al.
Postprandial blood glucose predicts
cardiovascular events and all-cause mortality in
type 2 diabetes in a 14-year follow-up: lessons
from the San Luigi Gonzaga Diabetes Study.
Diabetes Care 2011;34(10):2237-2243.
4. Takao T, Suka M, Yanagisawa H, Iwamoto Y. The
impact of postprandial hyperglycemia at clinic
visits on the incidence of cardiovascular events
and all-cause mortality in patients with type 2
diabetes [published online December 15, 2016].
J Diabetes Investig doi: 10.1111/jdi.12610.
5. Standl E, Schnell O, Ceriello A. Postprandial
hyperglycemia and glycemic variability:
should we care? Diabetes Care 2011;34(Suppl
2):S120–S127.
6. Ceriello A. Point: postprandial glucose levels
are a clinically important treatment target.
Diabetes Care 2010;33(8):1905-1907.
Dr Ceriello is P.I. of the Research
Department on Diabetes and CVD,
Institut d’Investigacions Biomèdiques
August Pi i Sunyer (IDIBAPS), Barcelona,
Spain; and Head Diabetes Department,
IRCCS MultiMedica, Milan, Italy.
EDITOR’S PICKS 7
VOL. 1 • NO. 2 • 2017