What is the significance of a serum creatinine (creatinine) level of 0.42 in a 12-year-old male?

From the Guidelines

A creatinine level of 0.42 mg/dL in a 12-year-old boy is generally within the normal range and not a cause for concern. According to the Schwartz Formula, which utilizes serum creatinine, patient height, and a constant to derive an estimated creatinine clearance (eCCL) [ 1 ], this value can be used to estimate the glomerular filtration rate (GFR). However, it's essential to consider that serum creatinine is affected by muscle mass, age, and gender, as well as renal tubular absorption and secretion [ 1 ].

Key Points to Consider

• Normal creatinine levels for children aged 12 years typically range from 0.4 to 0.8 mg/dL, with some variation depending on the specific laboratory reference ranges.
• Creatinine is a waste product produced by muscle metabolism and is filtered by the kidneys, so its level in the blood reflects kidney function [ 1 ].
• Children naturally have lower creatinine levels than adults because they have less muscle mass.
• As the child grows and develops more muscle, his creatinine levels will gradually increase.

Recommendations

• No intervention is needed for this creatinine value, as it indicates normal kidney function.
• Regular health check-ups should continue as recommended by the pediatrician, but this specific creatinine value does not require any special follow-up or treatment.
• If there were other concerning symptoms or abnormal lab values, those would need to be evaluated separately.

Additional Considerations

• The pediatric modified RIFLE criteria, which utilize a combination of the eCCL by the Schwartz method and urine output, can inform the severity of renal injury in children with acute renal injury [ 1 ].
• Renal insufficiency that would necessitate combined liver and kidney transplant (CLKT) is less common in children than adults, but significant renal disease can be associated with certain conditions, such as primary hyperoxaluria, congenital hepatic fibrosis, and methylmalonic acidemia [ 1 ].

From the Research

Creatine Levels in 12-Year-Old Boy

• The creatine level of 0.42 in a 12-year-old boy is not directly addressed in the provided studies, as they primarily focus on the effects of creatine supplementation on renal function in adults and young athletes.
• However, it is mentioned in the study by 2 that the safety of creatine in children and adolescents has not been established.
• The study by 3 investigated the effects of creatine supplementation on biomarkers of hepatic and renal function in young trained rats, and found that creatine supplementation promoted hepatic and renal function challenge in young rats submitted to moderate exercise training.

Renal Function and Creatine Supplementation

• The studies by 2, 4, and 5 suggest that creatine supplementation is generally safe for healthy adults and does not significantly alter renal function.
• However, the study by 2 notes that creatine supplementation may be associated with an increased risk of renal dysfunction in people with a history of renal disease or those taking nephrotoxic medications.
• The study by 5 found that creatine supplementation did not significantly alter serum creatinine levels or plasma urea values.

Considerations for Children and Adolescents

• As mentioned earlier, the safety of creatine in children and adolescents has not been established, according to the study by 2.
• The study by 3 provides some insight into the effects of creatine supplementation on young animals, but more research is needed to determine the safety and efficacy of creatine supplementation in children and adolescents.