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GLP-1 Agonists
These drugs are glucagon like peptide-1 (GLP-1) receptor agonists, also
known as incretin-mimetics. They are well established in the treatment of type
2 diabetes in adults. GLP-1 agonists work by increasing the secretion of
insulin, whilst decreasing the secretion of glucagon. They also slow glucose
absorption into the bloodstream by reducing the speed at which the stomach
empties after eating, thus increasing satiety after a meal.
Exenatide
Data from adults indicates Exenatide suppresses appetite, resulting in the
positive side effect of significant reduction in BMI, body fat and body weight.
Weight loss is reported to be progressive and persistent for up to 2 years [68].
Kelly et al. carried out a 6 month, randomised, open-label, crossover pilot trial
examining the effectiveness of Exenatide on reducing BMI in both children
and adolescents with extreme obesity [69]. Twelve children and adolescents
aged 9-16 years old were enrolled in the study, and Exenatide injections were
administered subcutaneously twice a day. Results showed children taking
Exenatide had significantly lower BMI (-1.7kg/m^2 ), and decreased body
weight (-3.9kg) compared to the control group. However, reduction of
percentage body fat was not statistically significant. The authors demonstrated
Exenatide had few side effects and was well tolerated by children and
adolescents, with mild nausea being the most common side effect in 36%.
These symptoms resolved with temporary dose reduction. Although an
injection regimen could be seen as a limitation of Exenatide’s use in children
and adolescents, compliance was quoted as greater than 94% [69].
Liraglutide
Liraglutide is another injectable long-acting GLP-1 analogue, and is also
an established drug used for the treatment of diabetes in adults. Results from
the SCALE-diabetes study showed that Liraglutide is associated with weight
loss (up to - 4.0% for 3mg and -2.71% for 1.8mg versus. placebo). Weight loss
of 5% or greater was documented in 54.3% and 40.4%, respectively
(compared to. 21.4% with placebo) [70]. A meta-analysis of trial data
regarding the effects of GLP-1 receptor agonists concluded that they had
significant effects on weight loss in both diabetic and non-diabetic obese
patients. Furthermore, in this meta-analysis there was no significant difference
in efficacy between Exenatide and Liraglutide [71]. The FDA approved the
use of Liraglutide for management of weight loss in adults in September 2014
and the drug was subsequently launched for this indication. Approval has been