Dr. Villagran-Orellana, Marcelo

La obesidad es una enfermedad inflamatoria, crónica, recurrente, progresiva y de etiología multifactorial, que afecta a más 650 millones de personas en el mundo. La carga física, emocional y económica que genera la obesidad no solo guarda relación con sus manifestaciones clínicas, sino también por su impacto a nivel sistémico y a largo plazo. En Chile, el crecimiento económico, la urbanización y la globalización han modificado profundamente el modo de vivir de la población lo que ha favorecido un ambiente obesogénico. Sin embargo, ¿qué factores han repercutido en el desarrollo de obesidad en Chile? ¿cuál ha sido el rol de cada uno de estos factores en el aumento de la prevalencia de esta patología? En la parte 1 de esta revisión discutiremos los principales factores no modificables que han repercutido en su desarrollo, desde la transición epidemiológica que vivió el país en la década de los 70, hasta las patologías endocrinas relacionadas.

Background: Numerous studies have identified the role of Fat-mass-associated-gene (FTO) in the development of obesity. Aim: To investigate the association of FTO gene with adiposity markers in Chilean adults. Material and Methods: 409 participants were included in this cross-sectional study. The association between FTO (rs9939609) genotype and adiposity markers was determined using linear regression analyses. Adiposity markers included were: body weight, body mass index, fat mass, waist circumference, hip circumference and waist/hip ratio. Results: A fully adjusted model showed a significant association between FTO genotype and body weight (2.16 kg per each extra copy of the risk allele [95% confidence intervals (CI): 0.45 to 3.87], p = 0.014), body mass index (0.61 kg.m-2 [95% CI: 0.12 to 1.20], p = 0.050) and fat mass (1.14% [95% CI: 0.39 to 1.89], p = 0.010). The greater magnitude of association was found between the FTO gene and fat mass when the outcomes were standardized to z-score. Conclusions: This study confirms an association between the FTO gene and adiposity markers in Chilean adults, which is independent of major confounding factors.

Background: Walking speed is a strong predictor of non-communicable diseases and mortality. Aim: To investigate the association of self-reported walking pace with adiposity, metabolic and cardiovascular markers in the Chilean population. Material and Methods: Analysis of data from 5,077 participants of the 2009-2010 National Health Survey (ENS 2009-2010). Walking speed was self-reported as average or slow pace. Body mass index (BMI), waist circumference (WC), blood pressure, blood glucose, glycosylated hemoglobin and lipid profile were the outcome. Results: In Chile, 11% (95% confidence intervals [CI]: 10.0; 12.7) of the population reported a slow walking pace. Compared with average walking people, those reporting a slow pace had a higher body weight (difference (∆) 5.65 kg [95% CI: 3.22; 8.09], p < 0.01), BMI (D 2.48 kg/m 2 [95% CI: 1.53; 3.44], p < 0.01), WC (D 6.23 cm [95% CI: 4.12; 8.34], p < 0.01), serum triglycerides (D 30,9 mg/dl [95% CI: 5,31; 57,5], p = 0.018), and lower HDL cholesterol (D -2.32 mg/dl [95% CI: -4,24; -0,34], p = 0.022). Those reporting a slow pace had also a higher odd of being obese (odds ratio (OR): 2.46 [95% CI: 1.82; 3.33], p < 0.01), being diabetic (OR: 1.54 [95% CI: 1.02; 2.40], p = 0.018) and having metabolic syndrome (OR: 2.03 [95% CI: 1.30; 3.18], p = 0.002). Conclusions: In Chilean adults, slow walking pace is associated with and unfavorable adiposity and lipid profile, including a higher probability of being obese, diabetic and having metabolic syndrome.

Chile tiene una de las tasas de obesidad más altas del mundo. Se estima que para el año 2030 las muertes atribuidas a esta enfermedad alcanzarían a 204 mil personas, incrementándose además los costos económicos asociados a esta patología. Las causas y los factores de riesgo asociados al desarrollo de obesidad son diversos. Sin embargo, existe consenso que una de las maneras más eficaces de prevenir y/o disminuir su prevalencia es abordando los factores de riesgo modificables, a través del fomento de hábitos de vida saludable con un enfoque integral, centrados en la alimentación saludable, práctica de actividad física, prevención del tabaquismo y consumo de alcohol, como también en el cuidado de la salud mental del individuo. No obstante, el desafío es cómo hacer realidad estos buenos propósitos. En este contexto, el objetivo de esta revisión, parte 2, fue investigar los principales factores modificables, con énfasis en los factores individuales, que han repercutido en el desarrollo de obesidad: desde una mirada global hasta el caso particular de Chile.

Objective: To study the association of SLC16A11 gene variants with obesity and metabolic markers in nondiabetic Chilean adults. Materials and methods: This cross-sectional study included 263 nondiabetic adults. The genotype of the rs75493593 polymorphism of SLC16A11 gene was performed by real-time PCR. It’s association with adiposity markers (body weight, BMI, waist circumference and fat mass percentage), metabolic markers (glucose, insulin, HOMAIR, leptin, total cholesterol, LDLc, HDLc, triglycerides, ALT, GGT and hsCRP) and blood pressure was analyzed by linear regression. Results: The minor allele (T) of the SLC16A11 gene (rs75493593) has a frequency of 29.7% among Chileans. Risk genotypes (GT and TT) were associated with a significant 1.49 mU/l increase in plasmatic insulin for each copy of the minor allele (95% CI: 0.12, 2.87, p < 0.05). This association remained significant after adjusting for socio-demographic variables, physical activity and smoking (1.36 mU/l, 95% CI: 0.16, 2.58 p < 0.05), but was lost when BMI was included as a confounding factor. Higher BMI was also significantly associated with polymorphic genotypes in SLC16A11, independent of sociodemographic variables. Conclusion: The minor allele of the SLC16A11 gene (T) is highly prevalent among Chileans and is associated with increased insulin and BMI in nondiabetic individuals. These findings suggest that the genetic variant in SLC16A11 is not only associated with type 2 diabetes as previously shown in Mexicans, but is also related to early metabolic alterations in healthy subjects that may lead to type 2 diabetes.