Inverse association between serum resistin and insulin resistance in humans.

AIM: To determine how serum concentrations of resistin are distributed in humans in relation to insulin resistance, type 2 diabetes, and obesity. METHODS: Cross-sectional, descriptive study carried out in a random sample (n=713, 43% men, 18-75 years) of general population of inhabitants of the Canary Islands (Spain). Serum resistin concentration, HOMA2-IR, anthropometric parameters, drug consumption and physical activity were recorded. RESULTS: There were no differences in resistin concentration between participants with and without diabetes (3.1+/-0.2 vs. 3.2+/-0.1ng/mL; p=0.566), or between obese and non-obese participants (3.1+/-0.1 vs. 3.2+/-0.1ng/mL; p=0.803). Individuals with abdominal obesity (waist-hip ratio [WHR] >or=1 in men or >or=0.9 in women) had lower concentrations of resistin (3.0+/-0.13 vs. 3.4+/-0.1ng/mL; p<0.001). The correlations between resistin and HOMA2-IR (r=-0.231; p<0.001) and between resistin and WHR (r=-0.202; p<0.001) were inverse. Multivariate analysis corroborated the inverse association of this cytokine with HOMA2-IR, WHR and, in women, also retained in the model the direct association between resistin and physical activity and the inverse association between resistin and antihypertensive agents. CONCLUSIONS: In this population resistin is inversely associated with insulin resistance and abdominal obesity.

Serum resistin and polymorphisms of androgen receptor GAGn and GGNn and aromatase TTTAn.

There is evidence that androgens are regulators of insulin resistance (IR), and may be involved in the regulation of resistin, a cytokine that has been related with IR. Earlier studies found that androgen receptor length polymorphisms CAGn and GGNn and the aromatase polymorphism TTTAn may influence receptor or enzyme activity and serum concentrations of androgens. This study was designed to determine whether polymorphism length was related to serum resistin concentration and to other variables related with IR. In 1,580 persons chosen randomly from the general population of the Canary Islands (Spain), we measured polymorphism length, waist circumference, waist/hip ratio, BMI, and serum glucose concentration. In smaller subgroups, we also measured C-peptide (n = 677), resistin (n = 583), and leptin concentration (n = 754) and estimated IR (homeostasis model assessment-IR (HOMA2-IR)). In men, polymorphism length correlated with resistin concentration (CAGn, r = 0.13, P = 0.031; TTTAn, r = 0.15, P = 0.005; GGNn, r = -0.15, P = 0.026), and the correlations were confirmed in multivariate regression models. The length of CAGn and TTTAn correlated inversely with C-peptide (r = -0.13, P = 0.016 and r = -0.21, P < 0.001, respectively) and with estimated IR (r = -0.12, P = 0.032 and r = -0.19, P = 0.001, respectively). In men, length of the CAGn, GGNn, and TTTAn was associated with serum resistin concentration. These results support the hypothesis that androgens may be involved in the regulation of resistin. Resistin may be a link between IR and androgens.

[Cigarette smoking among adolescents. Estimated prevalence by a questionnaire and serum cotinine]. / Tabaquismo en adolescentes. Prevalencia estimada mediante declaración y cotinina sérica.

BACKGROUND: The tobacco smoking epidemic is causing more deaths than anyone before. Young population is the main aim of tobacco advertisements. We estimated the prevalence of tobacco use among adolescents and their environment, the agreement of questionnaire and serum cotinine and the total prevalence of exposure (active plus pasive). SUBJECTS AND METHODS: Cross-sectional study in 439 highschool students. We obtained a blood sample and anonimously inquired about their tobacco consumption and the existence of smokers in their environment. We analized the agreement between both methods. RESULTS: 56% have ever smoked tobacco. Declared prevalence of consumption was 34% (CI95%= 29.49-38.51), being 40% among girls and 23% among boys. The agreement between cotinine and declaration was high only in voluntary smokers (Kappa = 0.68 for 1 o more cigarettes/day and Kappa = 0.76 for 10 or more cigarettes/day). Smoking prevalence of the famliy, friends and school among smokers was higher (80%, 71% and 88%, respectively) than among non smokers (65%, 24% and 78%). Combining questionnaire and cotinine it was estimated that total prevalence of exposure was larger than 64%. CONCLUSIONS: The high prevalence of exposure and the asociation of tobacco smoking among adolescents and their environment demands an educational program against tobacco including family, social and school environments. The agreement between declaration and serum cotinine is high only when consumption is daily.

[Maternal participation to improve the effectiveness of diet education in children]. / Participación materna para mejorar la efectividad de la educación dietética en la infancia.

OBJECTIVE: To find out whether dietetic education in children improve its effectiveness with participation of mothers. DESIGN: We made a field try. SETTING: Two primary schools in Taco (La Laguna). SUBJECTS: We included every students who was in 7.o course in both schools (139 children). INTERVENTION: We assigned the children of one school to the educative intervention with mothers and the other school to the dietetic education without mothers. The intervention consist of four lectures about the fat food and the good feed. MEASUREMENTS AND MAIN RESULTS: We measured the dietetic knowledge with a questionnaire. And we made two plasmatic analysis to measure the lipidemia pre and postintervention. We excluded unauthorized children and those with more than one absence in our four classes. Both children groups showed a significative improvement in their knowledge (p < 0.05). The cholesterolaemia only decreased in the group with mothers (p = 0.01). It had a pradoxical diminishment of cholesterol HDL at the beginning was greater than 170 mg/dl, the reduction was more important yet in the group with mothers. CONCLUSIONS: The dietetic education can have variations in its effectiveness according the method employed and people who receive it. In the dietetic education of children the inclusion of mothers improve its effectiveness.