SDMA

Introduction

As a Nurse Practitioner with an autonomous practice in Florida, I often find myself discussing various biomarkers with patients to help them understand their health better. One such important, yet lesser-known, biomarker is Symmetric Dimethylarginine (SDMA). SDMA has emerged as a significant indicator in assessing kidney function and cardiovascular function risk. In this article, we’ll delve into the background of SDMA, its clinical implications, standard ranges, interfering factors, and the effects of certain drugs on SDMA levels.

Background of SDMA

Symmetric Dimethylarginine (SDMA) is a metabolite derived from the amino acid L-arginine. It plays a crucial role in the regulation of nitric oxide (NO) production by competing for cellular arginine. Nitric oxide is essential for vascular health as it facilitates vasodilation and maintains endothelial function. When SDMA levels are elevated, the availability of arginine decreases, leading to reduced NO production. This reduction can contribute to endothelial dysfunction, subsequently increasing the risk for cardiometabolic diseases.

SDMA and Its Role in Kidney Function

SDMA is predominantly eliminated from the body through the kidneys. Therefore, it serves as a useful marker for renal function. Elevated levels of SDMA are indicative of reduced renal clearance and are often associated with a decreased eGFR, a critical measurement in assessing kidney health. Unlike creatinine, another marker for kidney function, SDMA is less influenced by muscle mass, making it a potentially more reliable indicator.

Clinical Implications of SDMA Levels

Low SDMA Levels

Low or optimal levels of SDMA are generally considered beneficial, as they suggest a reduced risk for cardiovascular disease (CVD) and renal dysfunction. Patients with low SDMA levels typically have better endothelial function and reduced inflammation. However, it is important to assess these levels in conjunction with other clinical evaluations and biomarkers to obtain a comprehensive understanding of one’s health.

High SDMA Levels

Elevated SDMA levels have several clinical implications:

1. Increased Risk of Cardiovascular Disease: High SDMA levels, particularly when accompanied by elevated ADMA levels, indicate an increased risk of endothelial dysfunction and cardiovascular disease. SDMA and ADMA together interfere with nitric oxide production, exacerbating endothelial damage.
   
2. Renal Dysfunction: Elevated SDMA levels directly correlate with compromised renal function. As SDMA is primarily excreted by the kidneys, increased levels reflect decreased renal clearance capacity.
   
3. Insulin Resistance and Diabetes: Elevated SDMA, often alongside high ADMA levels, is among the earliest indicators of insulin resistance. This condition is a precursor to type 2 dysglycemia and is implicated in approximately 70% of heart attacks. Thus, high SDMA may signal the increased risk or presence of diabetes or pre-diabetes.
   
   

Standard Ranges for SDMA

The standard range for SDMA measurements in U.S. units is 73.00 – 135.00 ng/mL, while the international units standard is 0.36 – 0.68 µmol/L. The optimal range, derived from research at the Cleveland Heart Lab, aligns with these standards, suggesting that levels within 0.00 – 135.00 ng/mL or 0.00 – 0.68 µmol/L are ideal.

Interfering Factors

Several factors can interfere with accurate SDMA measurements:

• Hydration Status: Dehydration can falsely elevate SDMA levels since reduced fluid intake can impair renal clearance.
  
• Dietary Intake: High protein diets can increase SDMA levels due to greater amino acid turnover.
  
• Age and Gender: Renal function naturally declines with age, potentially influencing SDMA levels. However, gender differences are minimal.
  
  

Drug Associations Affecting SDMA Levels

Certain medications can affect SDMA levels, either increasing or decreasing them:

Drugs That May Increase SDMA Levels

• NSAIDs: These can reduce renal blood flow, thereby decreasing SDMA clearance.
  
• ACE Inhibitors: While beneficial for heart health, ACE inhibitors can affect renal function, potentially leading to elevated SDMA levels.
  
• Diuretics: These medications can alter fluid balance and renal function, impacting SDMA levels.
  
  

Drugs That May Decrease SDMA Levels

Currently, there are limited known pharmaceutical agents that directly decrease SDMA levels. However, medications that improve renal function or increase nitric oxide availability might indirectly influence SDMA concentrations.

Conclusion

Regular monitoring of SDMA levels can provide valuable insights into renal function and cardiovascular risk, allowing for early intervention and management. As a functional medicine provider in Florida, integrating evidence-based therapies with regenerative medicine medical care services—where endothelial health and renal function are critical—we offer patients a regenerative, preventive framework to rebuild resilience and optimize wellness. Call (904) 799-2531 or schedule online to request your personalized cardiovascular and renal health assessment.

Further Reading

1. Zoccali C, et al. “Symmetric Dimethylarginine and Mortality in Patients with Chronic Kidney Disease Stage 2–5.” Clin J Am Soc Nephrol. 2009;4(5):839–846. https://pubmed.ncbi.nlm.nih.gov/19389800/
   
2. Kielstein JT, et al. “Symmetric Dimethylarginine (SDMA) as Endogenous Marker of Renal Function—Correlation with GFR.” Nephrol Dial Transplant. 2006;21(9):2446–2451. https://pubmed.ncbi.nlm.nih.gov/16790453/
3. Sydow K, et al. “ADMA and SDMA: A Challenge for Pharmacological Modulation of the L-Arginine–NO Pathway.” Br J Pharmacol. 2008;155(4):360–368. https://pubmed.ncbi.nlm.nih.gov/17982346/