Background
Obesity is a chronic condition that affects millions of people worldwide, and is a major risk factor for many diseases, including chronic kidney disease (CKD). Excessive body weight can directly contribute to the deterioration of kidney function through several mechanisms, including hypertension, type 2 diabetes, and increased systemic inflammation (Navaneethan et al., 2010). In recent years, treatment options for obesity have evolved, including bariatric surgery and novel medications such as glucagon-like peptide-1 (GLP-1) receptor agonists (incretins). Although both strategies can promote weight loss and improve metabolic outcomes, recent studies suggest that bariatric surgery may be more effective in preserving kidney health than GLP-1 medications.
Mechanisms of action of bariatric surgery and GLP-1 drugs
Bariatric surgery, also known as metabolic surgery, includes procedures such as gastric bypass and sleeve gastrectomy. These procedures dramatically reduce food intake and promote hormonal changes that affect the regulation of metabolism (Rubino et al., 2016). In addition to weight loss, bariatric surgery has been shown to significantly improve glycemic control, reduce blood pressure, and lower levels of inflammation, all of which contribute to the maintenance of kidney function (Ikramuddin et al., 2018). Liraglutide and semaglutide work by increasing insulin secretion, reducing appetite, and promoting weight loss. These drugs have been particularly effective in improving glycemic control in patients with type 2 diabetes and have been shown to protect against kidney damage. However, GLP-1-induced weight loss is generally more moderate than that achieved with bariatric surgery.
Kidney health: bariatric surgery vs. GLP-1
A study published by Cohen et al. (2021) compared the effects of bariatric surgery and GLP-1 medications on kidney health in obese patients with and without type 2 diabetes. The results showed that patients who underwent bariatric surgery had a more significant reduction in the risk of developing chronic kidney disease than those treated with GLP-1 medications. In particular, bariatric surgery was associated with a more significant reduction in albuminuria (a measure of protein loss in the urine, indicative of kidney damage) and a slower decline in glomerular filtration rate (GFR), a key indicator of kidney function (Hanna et al., 2019). This benefit may be attributed to greater and more rapid weight loss achieved through surgery, as well as metabolic effects beyond simple reduction in body mass, such as decreased hypertension and more sustainable improvements in glycemic control (Chang et al., 2014). Additionally, bariatric surgery has shown superior anti-inflammatory effects, which may play a crucial role in protecting long-term renal function (Gletsu-Miller et al., 2009).
Clinical implications and discussion
Although GLP-1 agents are a viable option for patients who are unable to undergo surgery or who prefer a less invasive strategy, bariatric surgery appears to offer superior renal protection, particularly in patients with severe obesity or uncontrolled diabetes. However, the choice of treatment should be tailored to the individual patient’s clinical condition, the risks associated with surgery, and personal preference. Bariatric surgery offers significant renal health benefits compared to GLP-1 agents, especially in patients with severe obesity and comorbidities such as type 2 diabetes. The long-lasting effects of surgery on glycemic control, blood pressure reduction, and improved renal function make it an effective treatment option for the prevention of kidney damage. However, further studies are needed to better understand the mechanisms underlying these differences and to optimize the treatment choice for patients with obesity and pre-existing kidney disease.
- Edited by Dr. Gianfrancesco Cormaci, PhD, specialist in Clinical Biochemistry.
Scientific references
Cohen RV et al. (2021). JAMA Network Open, 4(4), e216436.
Hanna A et al. (2019). Kidney International, 95(6), 1218-25.
Tuttle KR et al. (2019). Diab Obes Metab, 21(8), 1972-1980.
Ikramuddin S et al. (2018). JAMA Surgery, 153(3), 217-225.
Rubino F, Nathan D et al. (2016). Diabetes Care, 39(6), 861.
Chang SH et al. (2014). JAMA Surgery, 149(3), 275-287.