Creatinine is derived from creatine that is an organic muscle breakdown product. Human body is composed of large and small groups of skeletal muscles that are in constant state of remodeling due to pressure, physical, hormonal and biochemical changes in the body. As a result of this breakdown, creatine is secreted in the blood and 2% of the converted into creatinine to be excreted by the kidneys. There can be many causes for low creatinine and corresponding treatment measures are available.
Here is a video of creatinine and other related information.
Human body performs all metabolic activities in a very schematic and systemic fashion. Malfunctioning of one organ or system can affect the systemic functioning of other organs and in turn create a state of disease and destruction. Healthcare providers assess the functioning of the body by measuring certain metabolites in the blood or urine. One such agent is creatinine that is required to assess renal functioning. Kidneys freely filter and secrete creatinine suggesting that no creatinine is reabsorbed by the blood unlike glucose, amino acids and electrolytes that include sodium and potassium. Due to this pattern, creatinine levels in the urine and blood are directly reflective of kidney functioning.
Normal Creatinine Values
|
Normal Values |
Men |
Women |
Infants |
Teens |
People with one kidney |
|---|---|---|---|---|---|
|
Creatinie Blood Level (mg/dL) |
0.6-1.2 |
0.5-1.1 |
0.2-1.2 |
0.5-1.0 |
1.8-1.9 |
*mg/ dL = miligrams/deciliters
Low creatinine levels are usually not considered bad or troublesome since it indicates that the kidneys are optimally functional. However, since most systems and tissues of the body work in coordination, it is recommended to observe the creatinine concentration if levels remain low for a long period. There may be several reasons or explanations of low creatinine levels in the serum; either low production of creatinine or increased excretion of creatinine.
Serum creatinine levels decreases proportionally with advancing age. This is most commonly due to lower basal metabolism and decreasing muscle mass. With age, metabolic activities decrease in the body due to changes in the hormonal concentration. Moreover, research suggest that the total body muscle mass decreases by 10 pounds after every 10 years that also contributes to low serum creatinine concentration.
During pregnancy, serum creatinine levels decrease during second trimester that is primarily attributed to high plasma volume that dilutes the creatinine levels in the blood. In addition, due to substantial increase in plasma volume, glomerular filtration rate also increases that suggest kidneys filter more blood and excrete more creatinine. According to clinical studies conducted on pregnant women, renal excretion of creatinine increases almost 30% more than her non- pregnant state. No intervention is needed since serum creatinine levels return to normal after delivery.
Certain degenerative muscular conditions like myasthenia gravis, inherent or acquired muscular dystrophies and other similar issues in which muscle metabolism is altered can lead to less muscle mass. Serum creatinine levels reflect total muscle mass in the body and a persistent decrease is indicative of systemic or localized problem of defective muscle metabolism. Myasthenia gravis is a progressive condition that eventually involves all voluntary muscles of the body by affecting the nervous supply. As a result of denervation (loss of nerve supply), no voluntary activity is possible, leading to disuse atrophy of muscles (presenting as low muscle mass and low creatinine levels). Same is true with genetic or acquired muscular dystrophies that make muscle fiber especially prone to degeneration and destruction.
High serum levels of creatinine indicate a defect in excretion (or renal issue); similarly, a persistent decrease in the serum creatinine concentration indicates a defect in the production of this compound. Liver is the primary site where detoxification activities are performed by the body. Like all waste products, nitrogenous compounds that are produced as a result of muscle metabolism, breakdown and remodeling activities is also converted into functional excretory forms by liver. Persistently low levels of creatinine indicate a likely pathology in the parenchyma of liver that may be because of a viral infection of liver (viral hepatitis) or drug induced hepatitis.
Creatinine is produced by the breakdown and metabolism of nitrogenous compounds or proteins in the body. Low creatinine levels indicate a low protein diet (foods like salmon, red meat and chicken liver) that eventually produces less nitrogenous wastes and creatinine.
As said previously, low creatinine levels are fairly uncommon in most normal and healthy individuals, yet when reported it is not considered troublesome in most cases. However, in some situations, it may be an early symptom of an underlying grave pathology that should be identified, diagnosis and monitored over time. Following are some optimal management options that should be employed if low creatinine levels persist for a long time: