Insulin Resistance and Adiposity in Relation to Serum β-Carotene Levels

Division of Pediatric Endocrinology and Metabolism, Nemours Children's Clinic, Jacksonville, FL 32207, USA.
The Journal of pediatrics (Impact Factor: 3.79). 02/2012; 161(1):58-64.e1-2. DOI: 10.1016/j.jpeds.2012.01.030
Source: PubMed


To determine the effects of placebo vs an encapsulated supplement of fruit and vegetable juice concentrate (FVJC) on serum β-carotene levels, insulin resistance, adiposity, and subclinical inflammation in boys.
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 corrected β-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), acute insulin response to intravenous glucose, along with abdominal fat mass (dual-energy x-ray absorptiometry) were also determined.
Baseline β-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 <1.047 μM 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).
A 6-month supplementation with FVJC in the presence of nutritional counseling was associated with an increase in serum β-carotene concentrations and a reduction in adiposity in conjunction with an improvement in insulin resistance in OW boys.

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    • "Animal intervention studies [7] [8] [9] [10] and human observational studies [11] [12] point to an inverse relationship between vitamin A status and body fat content. The concentration of BC in human adipocytes is reduced in obesity [13] and increases in serum levels of BC through diet associate with a reduction in adiposity in overweight children [14]. Studies in cell culture models and adult animals indicate that reduction of body fat by dietary vitamin A can be largely explained by its metabolism to biologically active retinoid derivatives, such as RA, which impact the differentiation and function of adipose tissues (reviewed in [1] [2]). "
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