Liraglutide treatment was associated with reductions
in cardiometabolic risk factors, including
waist circumference, blood pressure, and
inflammatory markers. Modest improvements in
fasting lipid levels were also observed, although
the clinical relevance of these improvements is
uncertain. Furthermore, patients in the liraglutide
group had greater reductions in fasting and
postprandial glycemic variables and more improvement
with respect to beta-cell function and
insulin sensitivity than did the placebo group.
The combination of weight loss and improved
glycemic control probably contributed to the
observed reductions in the prevalence of prediabetes
and the delayed onset of type 2 diabetes.
There were improvements in health-related quality
of life, notably physical function, with liraglutide,
as compared with placebo.
The safety profile of liraglutide was consistent
with findings in previous reports.9-11,22,23 Gastrointestinal
disorders are common and mostly
transient side effects of treatment.23 Gallbladderrelated
events were more common with liraglutide
than with placebo; patients with such events
had above-average weight loss, which is consistent
with the known risk of gallstones in association
with weight loss.24 Other mechanisms
may be involved.25 In the current trial, half the
pancreatitis cases in the liraglutide group were
associated with gallstones, and elevations of pancreatic
enzymes were not predictive. The lack of
a treatment effect on calcitonin concentration
and the absence of C-cell hyperplasia or medullary
thyroid carcinoma events are consistent with
the prior observation that liraglutide exposure is
not associated with medullary thyroid carcinoma
in humans.26 The reason for the numerical
imbalance in breast neoplasms that we observed
is unclear; whether there was enhanced ascertainment
related to greater weight loss is unknown.
The clinical relevance of increased resting
pulse with liraglutide is unknown but is probably
related to the drug class.27 The presence of
glucagon-like peptide-1 receptors on the sinoatrial
node suggests a direct chronotropic effect.28
No increase in the number of serious cardiovascular
events was observed in the liraglutide
group, and beneficial effects of liraglutide were
seen with respect to blood pressure and other
cardiometabolic variables.
Limitations of the trial include the use of lastobservation-carried-forward
imputation in the prespecified
primary analyses.29 However, the robustness
of the primary analyses was confirmed in
sensitivity analyses with the use of alternative
imputation methods to account for patients who
withdrew from the trial. Furthermore, no correction
for multiple testing was performed for secondary
end points. Strengths of the trial include
the large sample size, the independent blinded
adjudication of specific adverse events, low attrition
rates as compared with other weight-loss
trials,30-32 and a lifestyle intervention with resultant
weight loss.
In conclusion, 3.0 mg of once-daily subcutaneous
liraglutide, as an adjunct to diet and exercise,
was associated with clinically meaningful
weight loss in overweight or obese patients, with
concurrent reductions in glycemic variables and
multiple cardiometabolic risk factors, as well as
improvements in health-related quality of life.
S