Insulin resistance and adiposity in relation to serumβ-carotene levels.
J Pediatr. 2012 Jul ;161(1):58-64.e1-2. Epub 2012 Feb 28. PMID: 22381025
Jose A Canas
OBJECTIVE: To determine the effects of placebo vs an encapsulated supplement of fruit and vegetable juice concentrate (FVJC) on serumβ-carotene levels, insulin resistance, adiposity, and subclinical inflammation in boys.
STUDY DESIGN: Thirty age-matched prepubertal boys (9 lean and 21 overweight (OW); age range, 6-10 years) were studied. All participants received nutrition counseling and were randomized to receive FVJC or placebo capsules for 6 months. Total cholesterol, triglycerides, lipid correctedβ-carotene, serum retinol, glucose, insulin, retinol binding protein-4, leptin, adiponectin, leptin-to-adiponectin ratio, high-sensitivity C-reactive protein, and interleukin-6 were measured before and after the 6-month intervention. Homeostasis model assessment-insulin resistance (HOMA-IR), acuteinsulin response to intravenous glucose, along with abdominal fat mass (dual-energy x-ray absorptiometry) were also determined.
RESULTS: Baselineβ-carotene concentrations correlated inversely with HOMA-IR, leptin-to-adiponectin ratio, and abdominal fat mass (P ≤ .01). FVJC intake increased β-carotene concentrations (P ≤ .001) but did not influence retinol or retinol binding protein-4. Retinol insufficiency<1.047μM was present in 18% of the entire cohort at baseline and in 37% at 6 months. HOMA-IR decreased after supplementation in the OW cohort, when adjusted for percent weight change (P = .014). The percent change in abdominal fat mass increased in the placebo group and decreased in the FVJC group (P = .029).
CONCLUSIONS: A 6-month supplementation with FVJC in the presence of nutritional counseling was associated with an increase in serumβ-carotene concentrations and a reduction in adiposity in conjunction with an improvement in insulin resistance in OW boys.