Explainer: GLP-1s and weight management
South Africa is facing a significant weight problem. Statistics indicate that nearly one-third of men and about two-thirds of women in the country are classified as obese. With the increasing availability of GLP-1 medications, there is hope for effective weight management for suitable patients.
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“The past decade has seen an enormous paradigm shift in the management of patients living with the disease of obesity.
“Numerous societies, including the World Health Organisation, now define obesity as a ‘chronic, relapsing, progressive disease state’,” explains Dr Charlene Wolberg, a general practitioner with a master’s degree in nutritional science who practises at Netcare Linksfield Hospital.
“Historically, the prevailing wisdom when people approached the medical community for help with obesity was to advise more exercise and fewer calories, but there has been growing recognition that this approach is not practically helpful for many patients in helping to keep their weight controlled.”
Lifestyle modification
A more nuanced understanding of what actually causes obesity has been accompanied by pharmaceutical and local regulatory developments in the treatments approved to support long-term weight management.
“There is known to be a significant correlation between being overweight and the development of other chronic conditions like type 2 diabetes and hypertension.
“Newer treatments approved for weight management in South Africa, including semaglutide, do not change the fact that lifestyle modification is essential in any treatment plan,” Dr Wolberg emphasises.
Together with a holistic treatment plan that includes dietary and physical activity, including both strength and resistance training, and psychological support, semaglutide is a prescription weekly injectable medication first indicated for type 2 diabetes that is showing promising weight-management results for appropriate patients.
GLP-1s
“Semaglutide is a glucagon-like peptide-1 (GLP-1) analogue that mimics endogenous GLP-1, a hormone released from the gut in response to eating.
“This molecule, in addition to sugar control and weight management, exerts beneficial effects on various organs, including the cardiovascular system, brain, kidneys, and liver,” Wolberg explains.
“These molecules are showing benefits beyond sugar control and weight loss, as studies have shown they offer a 20% reduction in various forms of heart disease in high-risk patients, are observed to decrease the incidence of stroke by 39%, offer kidney protection, and, in addition, inflammation can be reduced by as much as 38%.”
One of the areas where GLP-1 analogues have an effect is the hypothalamus, or ‘appetite control centre’ of the brain. The GLP-1 hormone increases feelings of fullness, leading to decreased appetite and, subsequently, less food intake.
“Importantly, these molecules also affect areas in the brain that control our hedonic or emotional attachment to food.
“I often describe it as if you have had a perfectly balanced dinner and are physiologically full, but then, sitting in front of the TV, you may start thinking about the bar of chocolate in your pantry.
“You may plan on eating only one or two squares, then suddenly find you have eaten most of the slab.
“GLP-1s dampen down those impulses and enable us to eat a square or two and feel satisfied,” she explains.
Pharmaceuticals
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Gastrointestinal motility
GLP-1 analogues, unlike their weight loss predecessors, are registered and deemed safe for chronic use when there is a legitimate medical need.
“Where indicated, patients must inform their healthcare providers if they are pregnant, and about all prescription and over-the-counter medications, vitamins, minerals, herbal products, and other supplements they are currently using.
“Due to its effect on gastrointestinal motility, which is basically how your digestive system moves food through your body, semaglutide may alter the absorption of orally administered medications, including oral contraceptives.
“This could potentially lead to reduced contraceptive efficacy and unintended pregnancies, necessitating consideration of additional or alternative birth control methods.
Given the possibility of weight regain after abruptly stopping the medication, Wolfberg suggests that healthcare practitioners and patients work together to find the lowest dosage to prevent weight regain.
“Several different dosing strategies are being investigated for chronic weight management, and there is more hope than ever for not only reaching and sustaining a healthy weight, but also for warding off many of the significant health risks obesity poses for otherwise healthy individuals,” concludes Wolberg.