Leucine requirement and splanchnic uptake of leucine in chronically undernourished adult Indian subjects.
BACKGROUND
We showed previously by the 24-h direct amino acid balance (DAAB) method that the leucine requirement of well-nourished Western and South Asian subjects is approximately 40 mg x kg(-1) x d(-1).


OBJECTIVE
It is not known whether this estimated leucine requirement is applicable in chronic undernutrition; therefore, we assessed the leucine requirement in Indian men with chronic, but stable, undernutrition.


METHODS
We studied 26 chronically undernourished men during 2 randomly assigned 7-d diet periods consisting of an L-amino acid diet (n = 20) and supplying either 14 and 30 (n = 10) or 22 and 40 (n = 10) mg leucine x kg(-1)x d(-1) or consisting of the subjects' habitual cereal-and-lentil-based diets (n = 6). The 24-h DAAB was estimated on day 6 by using a [13C]leucine tracer infusion. The splanchnic uptake of leucine was determined at an intake of 40 mg x kg(-1) x d(-1) by administering [2H3]leucine orally.


RESULTS
By using mixed-models linear regression of leucine balance against leucine intake, we estimated a zero leucine balance at a leucine intake of 39.6 mg x kg(-1) x d(-1). The splanchnic first-pass uptake of [2H3]leucine was 22.7% and 11.5% of the intake in the fasted and fed phases, respectively. The subjects were in neutral leucine balance with their habitual cereal-and-lentil-based diets.


CONCLUSIONS
On the basis of the 24-h DAAB approach, a mean leucine requirement of 40 mg x kg(-1) x d(-1) is proposed for healthy and for chronically undernourished Indian adults.
Kurpad
Anura V
AV
Department of Physiology and Division of Nutrition, St John's Medical College, Bangalore, India.
Regan
Meredith M
MM
Raj
Tony
T
Varalakshmi
Sureka
S
Gnanou
Justin
J
Thankachan
Prashanth
P
Young
Vernon R
VR
D000328:Adult; D001823:Body Composition; D001835:Body Weight; D001944:Breath Tests; D002153:Calorimetry, Indirect; D002247:Carbon Isotopes; D002908:Chronic Disease; D003903:Deuterium; D004032:Diet; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D004041:Dietary Fats / Q000008:administration & dosage; D002523:Edible Grain; D005215:Fasting; D005502:Food; D006801:Humans; D007194:India; D007262:Infusions, Intravenous; D027806:Lens Plant; D007930:Leucine / Q000008:administration & dosage* / Q000032:analysis / Q000493:pharmacokinetics*; D008297:Male; D009748:Nutrition Disorders / Q000378:metabolism / Q000628:therapy*; D009751:Nutritional Requirements; D010084:Oxidation-Reduction; D013152:Splanchnic Circulation; D014781:Viscera / Q000378:metabolism*
D002247:Carbon Isotopes; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D003903:Deuterium; D007930:Leucine