Abdominal obesity and low physical activity are associated with insulin resistance in overweight adolescents: a cross-sectional study

ABSTRACT: Background: Previous studies have assessed the metabolic changes and lifestyles associated with overweight adolescents. However, these associations are unclear amongst overweight adolescents who have already developed insulin resistance. This study assessed the associations between insulin resistance and anthropometric, metabolic, inflammatory, food consumption, and physical activity variables amongst overweight adolescents. Methods: This cross-sectional study divided adolescents (n = 120) between 10 and 18 years old into 3 groups: an overweight group with insulin resistance (O + IR), an overweight group without insulin resistance (O-IR), and a normal-weight control group (NW). Adolescents were matched across groups based on age, sex, pubertal maturation, and socioeconomic strata. Anthropometric, biochemical, physical activity, and food consumption variables were assessed. Insulin resistance was assessed using homeostatic model assessment (HOMA Calculator Version 2.2.2 from ©Diabetes Trials Unit, University of Oxford), and overweight status was assessed using body mass index according to World Health Organization (2007) references. A chi-square test was used to compare categorical variables. ANOVAs or Kruskal-Wallis tests were used for continuous variables. Multiple linear regression models were used to calculate the probability of the occurrence of insulin resistance based on the independent variables. Results: The risk of insulin resistance amongst overweight adolescents increases significantly when they reach a waist circumference > p95 (OR = 1.9, CIs = 1.3-2.7, p = 0.013) and watch 3 or more hours/day of television (OR = 1.7, CIs = 0.98-2.8, p = 0.033). Overweight status and insulin resistance were associated with higher levels of inflammation (hsCRP ≥1 mg/L) and cardiovascular risk according to arterial indices. With each cm increase in waist circumference, the HOMA index increased by 0.082; with each metabolic equivalent (MET) unit increase in physical activity, the HOMA index decreased by 0.026. Conclusions: Sedentary behaviour and a waist circumference > p90 amongst overweight adolescents were associated with insulin resistance, lipid profile alterations, and higher inflammatory states. A screening that includes body mass index, in waist circumference, and physical activity evaluations of adolescents might enable the early detection of these alterations

Reproductive biology of Sporobolus phleoides Hack. (Poaceae) an endemic phalophyte grass of Argentina

Sporobolus phleoides is an endemic grass of Argentina considered an important genetic resource for saline environments due to its salinity tolerance. Basic information about its reproductive biology is needed to adequately preserve its genetic variability. Hence, we studied its breeding system through phenology, embryological analysis, and self-pollination versus open-pollination treatments in six populations collected from four provinces of Argentina. The results indicated that S. phleoides is mainly autogamous with a high fertility rate. Cleistogamous and chasmogamous spikelets are isomorphic and occur simultaneously on the inflorescence, with higher percentages of cleistogamy found in the basal region of the panicle. The average percentage of cleistogamy during the study period was 23 % for all populations evaluated. The development of the embryo sac follows the typical pattern of grasses and indicates normal sexual reproduction. This study provides the basis for programming genotype collections for gene banks and future plans of domestication.Fil: Richard, Geraldina Alicia. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Pensiero, Jose Francisco. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Cerino, María Carolina. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Galati, Beatriz Gloria. Universidad de Buenos Aires. Facultad de Agronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gutierrez, Hugo Francisco. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentin