OBJECTIVE To examine whether physical activity attenuates the effect of the FTO rs9939609 polymorphism on body fat estimates in adolescents. DESIGN Cross-sectional study. SETTING Athens, Greece; ...Dortmund, Germany; Ghent, Belgium; Heraklion, Greece; Lille, France; Pécs, Hungary; Rome, Italy; Stockholm, Sweden; Vienna, Austria; and Zaragoza, Spain, from October 2006 to December 2007. PARTICIPANTS Adolescents from the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study (n = 752). MAIN EXPOSURE Physical activity. MAIN OUTCOME MEASURES The FTO rs9939609 polymorphism was genotyped. Physical activity was assessed by accelerometry. We measured weight, height, waist circumference, and triceps and subscapular skinfolds; body mass index (BMI calculated as weight in kilograms divided by height in meters squared) and body fat percentage were calculated. RESULTS The A allele of the FTO polymorphism was significantly associated with higher BMI (+0.42 per risk allele), higher body fat percentage (+1.03% per risk allele), and higher waist circumference (+0.85 cm per risk allele). We detected significant or borderline gene × physical activity interactions for the studied body fat estimates (for interaction, P = .02, .06, and .10 for BMI, body fat percentage, and waist circumference, respectively). Indeed, the effect of the FTO rs9939609 polymorphism on these body fat parameters was much lower in adolescents who met the daily physical activity recommendations (ie, ≥60 min/d of moderate to vigorous physical activity) compared with those who did not: +0.17 vs +0.65 per risk allele in BMI, respectively; +0.40% vs +1.70% per risk allele in body fat percentage, respectively; and +0.60 vs +1.15 cm per risk allele in waist circumference, respectively. CONCLUSION Adolescents meeting the daily physical activity recommendations may overcome the effect of the FTO rs9939609 polymorphism on obesity-related traits.Arch Pediatr Adolesc Med. 2010;164(4):328-333-->
Leptin is thought to represent a peripheral signal involved in the regulation of energy balance. Its action has been studied in animals and obese subjects. Little is known about leptin’s role during ...negative energy balance.
The objective was to evaluate the relation between energy turnover, body composition, and plasma leptin concentrations in anorexia nervosa (AN).
Sixteen weight-stable women with AN were compared with 22 control subjects and 14 rehabilitated AN patients (R-AN). Basal metabolic rate (BMR) was measured by indirect calorimetry; fat-free mass (FFM) and fat mass (FM) were calculated according to a 4-compartment model. Plasma leptin was determined by radioimmunoassay.
The BMR of AN patients (2.73 ± 0.37 kJ/min) was significantly lower than that of control subjects (3.45 ± 0.34 kJ/min) (P < 0.001), even after adjustment for FFM (2.92 ± 0.33 kJ/min in AN patients and 3.30 ± 0.26 kJ/min in control subjects; P < 0.004). Plasma leptin concentrations in AN patients were 76% lower than in control subjects, even after body fat was controlled for. In R-AN patients, BMR was not significantly different from that of control subjects and leptin concentrations were generally close to normal. Plasma leptin concentrations correlated significantly with FM (r2 = 0.53, P < 0.0000) and BMR, even after adjustment for FFM (r2 = 0.21, P < 0.0003).
BMR and plasma leptin concentrations are depressed in patients with AN; this is not explained by body-composition changes. The relation between leptin and BMR suggests that leptin plays a role in the energy sparing response to exposure to chronic energy deficiency. The return of BMR to normal and the significant increase in leptin concentrations in R-AN patients suggests a full reversibility of this adaptation mechanism.
Full text
Available for:
CMK, GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
PDF
