From the Guidelines
Low total protein on a Comprehensive Metabolic Panel (CMP) is most commonly caused by malnutrition or poor dietary protein intake, and treatment should focus on addressing the underlying cause, which may include dietary changes to increase protein intake to 1.2-1.3 g/kg/day, as recommended by the National Kidney Foundation 1.
Causes of Low Total Protein
The causes of low total protein can be categorized into several groups, including:
- Malnutrition or poor dietary protein intake
- Malabsorption disorders like celiac disease or inflammatory bowel disease
- Liver disease that impairs protein synthesis
- Kidney disease with protein loss in urine
- Severe burns or hemorrhage causing protein loss
- Certain gastrointestinal conditions
- Pregnancy, which can temporarily lower protein levels When evaluating low protein, it's essential to check both albumin and globulin components, as albumin typically accounts for about 60% of total protein.
Treatment and Management
Treatment focuses on addressing the underlying cause, which may include:
- Dietary changes to increase protein intake to 1.2-1.3 g/kg/day, as recommended by the National Kidney Foundation 1
- Treating malabsorption disorders
- Managing liver or kidney disease
- Supplementing with protein in severe cases Additional testing may include urinalysis to check for protein loss, liver function tests, and tests for malabsorption.
Importance of Protein Intake
Low protein can affect many bodily functions, including fluid balance, immune response, and transport of medications and hormones, making identification and treatment of the underlying cause essential. The National Kidney Foundation recommends a dietary protein intake of 1.2-1.3 g/kg/day for patients with chronic renal failure 1, and similar recommendations may apply to other patients with low total protein. However, it's crucial to note that individual protein requirements may vary, and patients should consult with their healthcare provider to determine the best course of treatment.
From the Research
Possible Causes of Low Total Protein on CMP
- Hypoalbuminemia, which can be associated with several different diseases, including cirrhosis, malnutrition, nephrotic syndrome, and sepsis 2
- Nephrotic syndrome, characterized by edema, proteinuria, hypoalbuminemia, and hyperlipidemia 3, 4, 5
- Other conditions such as burns, hemorrhagic shock, and prevention of hepatorenal syndrome, although albumin supplementation is not always the first-choice treatment for these conditions 2
Diseases Associated with Low Total Protein
- Cirrhosis, which can lead to hypoalbuminemia due to liver dysfunction 2
- Nephrotic syndrome, which can cause hypoalbuminemia due to excessive proteinuria 3, 4, 5
- Sepsis, which can lead to hypoalbuminemia due to inflammation and capillary leak syndrome 2
- Malnutrition, which can cause hypoalbuminemia due to inadequate protein intake 2
Clinical Evaluation and Management
- Clinical evaluation involves distinguishing primary and secondary causes of nephrotic syndrome and monitoring for disease complications, including blood clots and serious infections 3, 4
- Treatment of nephrotic syndrome typically consists of sodium restriction, fluid restriction, loop diuretics, angiotensin-converting enzyme inhibitor or angiotensin receptor blocker therapy, and careful assessment for possible disease complications 4
- Immunosuppressive treatment, including corticosteroids, may be used for nephrotic syndrome, although evidence is lacking 4