Intervention Study With Omega-3 Fatty Acids for Weight Loss and Insulin Resistance in Adolescents
Condition: Obesity; Insulin Resistance
MeSH terms: Insulin Resistance; Weight Loss
Study type: Interventional

Summary: 
      The purpose of this study is to evaluate if a supplement containing omega-3 long chain
      polyunsaturated fatty acids for three months reduce obesity and insulin resistance to obese
      adolescents if administered together with a hypocaloric diet.
    

Detailed description: 
      Background: In 2006, the prevalence of overweight and obesity combined in scholar and
      adolescents in Mexico was 26% and 31% respectively, which represents more than double of that
      reported in year 2000. Together with such increments in the obesity rates, it was observed
      similar increases in the incidence of other metabolic conditions such as insulin resistance
      (IR). In a very simplistic manner, it seems that the link between obesity and IR is a chronic
      inflammatory status because the adipose tissue-derived inflammatory molecules interfere with
      the uptake of fatty acids and glucose in peripheral tissues.

      On the other hand, it is accepted that the long-chain polyunsaturated fatty acids (LCPUFA)
      omega-3 exhibit anti-inflammatory properties. In addition, it has been also demonstrated the
      beneficial effect exerted by such fatty acids on insulin sensitivity, and in stabilizing the
      weight lost achieved with hypocaloric diets.

      At present, the prevalence of overweight and obesity combined are in the range of 41-43% in
      the adolescent population that attend the four areas of influence of the Mexican Institute of
      Social Security (IMSS) in Mexico City. Interventions addressed to improve the nutritional
      status of these groups of age are expected to impact the risk for IR and its associated
      co-morbidities.

      Objective: To evaluate the impact of supplementation with LCPUFA omega-3, together with a
      dietary strategy, on obesity and insulin resistance in a sample of obese adolescents attended
      in the IMSS.

      Methods: In a randomized clinical design, 300 obese individuals, 12-18 years old, will be
      selected. At selection, individuals will be randomly assigned to receive daily a capsule with
      1.1 g LCPUFA omega-3 during three mo together with a hypocaloric diet which follows the World
      Health Organization (WHO) recommendations (D+O3), or to receive daily a capsule with 1.0 g
      sunflower oil and a similar diet (P+D). After randomization, dietary information (24h-recall
      and FFQ), anthropometric measurements, and peripheral blood samples, will be obtained. Blood
      samples will be used to determine fasting plasma glucose and insulin, and erythrocytes fatty
      acid profile; such determinations will be repeated at three and six mo of follow-up.
      Anthropometry and 24 h-recalls will be repeated monthly.

      For follow-up, studied subjects will be evaluated monthly to deliver capsules and to check
      for dietary adherence. Treatments will be administered during three months and the follow-up
      will continue throughout six months. At the end of the follow-up it is expect that the D+O3
      group will present: a) higher decreases in mean weight and body mass index (BMI), b) greater
      decreases in the mean fasting insulin concentration, homeostasis model assessment (HOMA)
      index, and IR frequency, c) longer duration of weight lost.

      Statistical analyses: Student and paired-t test will be used for inter and intra group
      comparisons respectively. Logistic regression models and repeated measures analyses will be
      conducted to evaluate the effect of treatments, adjusting by diet and weight loss, as well as
      by confounders such as puberty and treatment adherence.

      Infrastructure: The Unit of Research in Medical Nutrition owes the equipment needed to
      conduct the laboratory determinations proposed in this research, as well as the personnel
      qualified to conduct, monitor, analyze and evaluate data from field investigation, specially
      that related to obesity and IR.
    

Intervention name(s): Omega3 and an hypocaloric diet.; Sunflower oil with an hypocaloric diet.
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): Thirty caps with the supplement will be provided every mo during three mo. Supplement will be administered as gel caps containing 1.1 g of DHA and EPA (®MaxEpa, Merck Laboratory) Hypocaloric diet will start at admission and will continue during the six months of follow-up. It will consist in providing a personalized diet including: a) reduction of 700 Kcal from the usual diet considering lipids and carbohydrates, b) increasing fruits and vegetables intake up to six portions daily each, and c) incrementing the intake of fiber to 30 g a day through the inclusion of whole grains.; Thirty caps with the placebo will be provided every mo during three mo. Placebo will be administered as gel caps containing 1g of sunflower oil, which is omega-3 free, and is not expected to produce anti-inflammatory or insulin sensitivity effects. Hypocaloric diet will start at admission and will continue during the six months of follow-up. It will consist in providing a personalized diet including: a) reduction of 700 Kcal from the usual diet considering lipids and carbohydrates, b) increasing fruits and vegetables intake up to six portions daily each, and c) incrementing the intake of fiber to 30 g a day through the inclusion of whole grains.
Other intervention name(s): DHA and EPA fatty acids; Docosahexaenoic fatty acid; Eicosapentaenoic fatty acid; ®MaxEpa, Merck Laboratory; Sunflower oil
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Supportive Care
Keywords: Obesity; Insulin resistance; Omega3 long chain polyunsaturated fatty acids