Question

Creatinine is formed from creatine. It is excreted by the kidneys with little reabsorption. When a patient follows a meat restricted diet, the size of the patient’s somatic protein pool is directly proportional to the amount of creatinine excreted.

Significant predictors of urinary creatinine concentration included age group, sex, race/ethnicity, body mass index, and fat-free mass. For instance, males excrete more creatinine than female. Additionally, the body does not distinguish between dietary creatine, which is converted to creatinine, from endogenously produced creatinine thus consumptions of a large amount of meat product affect the level of creatinine in the urine.

1. How do you estimate CHI (creatinine-height index) using creatinine excretion?

2. What are the limitations of using both labs?

Answer 1

1. Creatinine height index is measured by :-

= Actual 24hr creatinine excretion / expected creatinine excretion.

Expected creatinine excretion for female is 18mg/kg and for male is 23mg/kg .

It is used to estimate the degree of protein depletion and repletion in malnourished children. In this 24hr urine sample is collected.

2. The limitations are :-

- inability to collect 24hr urine

- consumption of large amount of meat