How Gastric Sleeve Bariatric Surgery Can Lower Your Long-Term Risk of Chronic Kidney Disease

By Del Mar Surgical – San Diego, California

Based on the article: https://www.medscape.com/viewarticle/bariatric-surgery-may-lower-long-term-ckd-risk-2025a1000ob8?form=fpf 

Introduction

At Del Mar Surgical in San Diego, our mission is to offer evidence-based guidance and support for individuals considering bariatric surgery as a life-changing step toward better health. A groundbreaking new study from Denmark, published in BMC Nephrology and reported by Medscape, demonstrates that bariatric surgery including both gastric sleeve surgery and Roux-en-Y gastric bypass may reduce long-term risk of chronic kidney disease (CKD) and kidney failure with replacement therapy (KFRT), while showing only minimal short-term kidney-related risks.

In this blog, we explore the findings of this study, with special attention to the benefits and considerations surrounding gastric sleeve surgery (SG), and how this weight-loss surgery can help protect kidney health for years to come.

Understanding the Study: Bariatric Surgery and Long-Term Kidney Outcomes

Study Design and Population

• Researchers in Denmark analyzed national registry data on adult patients who underwent either Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) between 2006 and 2018.
• The surgical group included 18,827 patients (17,200 RYGB; 1,627 SG) matched 1:5 by age and sex to 94,135 non-surgical controls with overweight/obesity. Another comparison was made to a general population cohort matched on age and sex.
• The median age was 41, about 76% were women, and follow-up averaged 8.1 years. Baseline estimated glomerular filtration rate (eGFR) and A1c levels were similar across all groups.

Kidney Outcomes Measured

The researchers tracked:

1. Acute Kidney Injury (AKI) – risk within 1 year after surgery
2. Nephrolithiasis (kidney stones) – risk at 10 years
3. Chronic Kidney Disease stages G3–G5 (CKD) – risk at 10 years
4. Kidney Failure with Replacement Therapy (KFRT) – dialysis or transplant, at 10 years

Key Findings: Risks and Benefits

• Within 1 year, bariatric surgery patients had a 2.7% risk of AKI, with a hazard ratio (HR) of 1.63 compared to non-surgical controls.
• Over 10 years, there was a 3.5% risk of nephrolithiasis, with HR of 1.73 for stones compared to controls.
• The 10-year risk of CKD (G3–G5) was just 0.4%, with HR of 0.41, reflecting a 59% lower risk compared to matched controls.
• The 10-year risk of KFRT was 0.2%, with HR of 0.63, equating to a 37% reduction in risk.

When broken down by procedure:

• AKI risk: 2.7% after RYGB vs 2.4% after SG
• Nephrolithiasis: 3.6% after RYGB vs just 1.2% after SG
• KFRT: 0.2% after RYGB vs 1.6% after SG

This shows that gastric sleeve surgery (SG) carries somewhat lower risks of kidney stones and acute kidney injury while still offering strong protection against long-term kidney disease.

Why Does Gastric Sleeve Surgery Protect Against CKD?

Obesity, Diabetes, and Kidney Health

Obesity is a major contributor to CKD, especially when paired with type 2 diabetes and high blood pressure. Bariatric surgery consistently improves these risk factors, which helps preserve kidney function over time.

Weight-loss surgery leads to:

• Better blood sugar control
• Lower blood pressure
• Reduced inflammation
• Healthier cholesterol and triglyceride levels

These changes help prevent CKD progression and protect long-term kidney health.

RYGB vs Sleeve Gastrectomy

• RYGB can increase risk of kidney stones due to changes in fat absorption that raise oxalate levels.
• SG has lower risk of nephrolithiasis (1.2% vs 3.6% at 10 years).
• Both surgeries protect against CKD, but sleeve gastrectomy may be a safer option for kidney health in some patients.

What This Means for Patients Considering Gastric Sleeve Surgery

1. Long-Term Kidney Protection
   Gastric sleeve surgery can significantly reduce long-term risk of CKD (stages G3–G5) and the need for dialysis or transplant (KFRT).
2. Short-Term Risks Are Manageable
   There is a small, increased risk of AKI and kidney stones, especially after RYGB. With SG, these risks are lower and are far outweighed by the long-term benefits.
3. SG May Be the More Kidney-Friendly Option
   For patients concerned about kidney health, sleeve gastrectomy offers powerful weight-loss benefits with lower risk of kidney complications.
4. Team-Based Care is Key
   At Del Mar Surgical, we use a collaborative approach that involves our surgeons, nephrologists, dietitians, and primary care providers to minimize risks and support your recovery.
5. Lifelong Lifestyle and Follow-Up Matter
   After surgery, we emphasize:
   • Staying well hydrated
   • Monitoring calcium and oxalate intake
   • Taking calcium citrate if needed
   • Routine lab checks for kidney function, blood sugar, and blood pressure

Additional Research That Supports These Findings

• Chang et al. (2016): Bariatric surgery improved kidney function in severely obese patients.
• Friedman et al. (2018): Sustained reduction in CKD risk 7 years after weight-loss surgery.
• Kassam et al. (2020): Bariatric surgery lowered risk of kidney function decline even with eGFR <90.
• Kukla et al. (2024): Bariatric surgery is safe and effective even in patients with advanced CKD.

These studies align with the new Danish findings showing gastric sleeve and other forms of metabolic surgery protect kidney health long term.

Conclusion

At Del Mar Surgical in San Diego, our goal is to help patients achieve lasting health through safe, effective bariatric surgery. The latest research confirms that gastric sleeve surgery not only promotes significant weight loss but also offers long-term protection against chronic kidney disease and kidney failure.

While short-term risks like acute kidney injury and nephrolithiasis exist, these are manageable with proper care—and are far outweighed by the long-term health benefits.

If you are considering bariatric surgery and are concerned about kidney health, our experienced team at Del Mar Surgical will guide you through every step. Together, we can help you transform your health, protect your kidneys, and build a longer, healthier future.