Benefits in quality of life following an obstructive sleep apnea screening and treatment program in patients with acute ischemic stroke. / Beneficios en la calidad de vida de un programa de cribado y tratamiento de apnea obstructiva del sueño en pacientes con ictus isquémico agudo.

INTRODUCTION: Obstructive sleep apnea (OSA) has been proposed as a factor that worsens stroke prognosis. Our aim was to determine if an OSA intervention could improve quality of life (QOL, first objective) and modified Rankin score (mRS, second objective). PATIENTS AND METHODS: The intervention group of this quasi-experimental study included patients with acute ischemic stroke <72 hours who underwent polygraphy and Continuous Positive Airway Pressure (CPAP) and hygienic-dietary measures if required. The control group followed routine clinical practice. The Short Form 36 Health Survey (SF-36) and mRS were applied at the sixth month after stroke in both groups. RESULTS: Fifty-five vs. sixty-two patients were included in the intervention and control group respectively. In the intervention group, 64.71% of patients accepted the proposed CPAP (16 cases with a good adherence). An improvement in SF-36 items was detected in the intervention group: physical functioning (p = 0.008), role physical (p = 0.002), bodily pain (p = 0.008), general health (p <0.001), vitality (p = 0.001) and role emotional (p = 0.015). In a per-protocol analysis, all these improvements were verified in the group of patients treated with good CPAP adherence (p < 0.05 in all the same SF-36 items). The percentage of patients with physical component summatory = 50 was higher in the intervention group (p = 0.003). There were no differences in the median of mRS (p = 0.262). CONCLUSIONS: Although more evidence is needed, a significant improvement in QOL was suggested after our OSA intervention, particularly in patients with good CPAP adherence.

TITLE: Beneficios en la calidad de vida de un programa de cribado y tratamiento de apnea obstructiva del sueño en pacientes con ictus isquémico agudo.Introducción. La apnea obstructiva del sueño (AOS) se ha propuesto como un factor de mal pronóstico en el ictus. Pretendemos determinar si una intervención sobre la AOS puede mejorar las escalas de calidad de vida (primer objetivo) y de discapacidad (segundo objetivo). Pacientes y métodos. El grupo de intervención de este estudio cuasi experimental incluye a pacientes con ictus isquémico agudo menor de 72 horas de evolución a quienes se les realizó poligrafía, así como presión positiva continua en las vías aéreas (CPAP) y medidas higienicodietéticas si se requerían. En el grupo de control se siguió la práctica clínica habitual. Se aplicaron las escalas Short Form 36 Health Survey (SF-36) y modified Rankin Score (mRS) en el sexto mes del ictus en ambos grupos. Resultados. Se incluyó a 55 y a 62 pacientes en el grupo de intervención y en el de control, respectivamente. En el grupo de intervención, el 64,71% de los pacientes aceptó la CPAP indicada (16 casos con buena adhesión). Se detectó una mejoría en los ítems de la escala SF-36 en el grupo de intervención: funcionamiento físico (p = 0,008), rol físico (p = 0,002), dolor corporal (p = 0,008), salud general (p menor de 0,001), vitalidad (p = 0,001) y rol emocional (p = 0,015). En un análisis por protocolo, todas estas mejorías se comprobaron en el grupo de pacientes tratados con CPAP con buena adhesión (p menor de 0,05 en todos los ítems de la SF-36). El porcentaje de pacientes con el sumatorio del componente físico = 50 fue más alto en el grupo de intervención (p = 0,003). No había diferencias en la mediana de la mRS (p = 0,262). Conclusiones. Aunque se necesitan más evidencias, nuestro estudio sugiere una mejoría significativa de la calidad de vida tras nuestra intervención en la AOS, especialmente en pacientes con buena adhesión a la CPAP.

Beneficios en la calidad de vida de un programa de cribado y tratamiento de apnea obstructiva del sueño en pacientes con ictus isquémico agudo / Benefits in quality of life following an obstructive sleep apnea screening and treatment program in patients with acute ischemic stroke

Introducción: La apnea obstructiva del sueño (AOS) se ha propuesto como un factor de mal pronóstico en el ictus. Pretendemos determinar si una intervención sobre la AOS puede mejorar las escalas de calidad de vida (primer objetivo) y de discapacidad (segundo objetivo). Pacientes y métodos: El grupo de intervención de este estudio cuasi experimental incluye a pacientes con ictus isquémico agudo < 72 horas de evolución a quienes se les realizó poligrafía, así como presión positiva continua en las vías aéreas (CPAP) y medidas higienicodietéticas si se requerían. En el grupo de control se siguió la práctica clínica habitual. Se aplicaron las escalas Short Form 36 Health Survey (SF-36) y modified Rankin Score (mRS) en el sexto mes del ictus en ambos grupos. Resultados: Se incluyó a 55 y a 62 pacientes en el grupo de intervención y en el de control, respectivamente. En el grupo de intervención, el 64,71% de los pacientes aceptó la CPAP indicada (16 casos con buena adhesión). Se detectó una mejoría en los ítems de la escala SF-36 en el grupo de intervención: funcionamiento físico (p = 0,008), rol físico (p = 0,002), dolor corporal (p = 0,008), salud general (p < 0,001), vitalidad (p = 0,001) y rol emocional (p = 0,015). En un análisis por protocolo, todas estas mejorías se comprobaron en el grupo de pacientes tratados con CPAP con buena adhesión (p < 0,05 en todos los ítems de la SF-36). El porcentaje de pacientes con el sumatorio del componente físico = 50 fue más alto en el grupo de intervención (p = 0,003). No había diferencias en la mediana de la mRS (p = 0,262). Conclusiones: Aunque se necesitan más evidencias, nuestro estudio sugiere una mejoría significativa de la calidad de vida tras nuestra intervención en la AOS, especialmente en pacientes con buena adhesión a la CPAP.

Introduction: Obstructive sleep apnea (OSA) has been proposed as a factor that worsens stroke prognosis. Our aim was to determine if an OSA intervention could improve quality of life (QOL, first objective) and modified Rankin score (mRS, second objective). Patients and methods: The intervention group of this quasi-experimental study included patients with acute ischemic stroke <72 hours who underwent polygraphy and Continuous Positive Airway Pressure (CPAP) and hygienic-dietary measures if required. The control group followed routine clinical practice. The Short Form 36 Health Survey (SF-36) and mRS were applied at the sixth month after stroke in both groups. Results: Fifty-five vs. sixty-two patients were included in the intervention and control group respectively. In the intervention group, 64.71% of patients accepted the proposed CPAP (16 cases with a good adherence). An improvement in SF-36 items was detected in the intervention group: physical functioning (p = 0.008), role physical (p = 0.002), bodily pain (p = 0.008), general health (p <0.001), vitality (p = 0.001) and role emotional (p = 0.015). In a per-protocol analysis, all these improvements were verified in the group of patients treated with good CPAP adherence (p < 0.05 in all the same SF-36 items). The percentage of patients with physical component summatory ≥ 50 was higher in the intervention group (p = 0.003). There were no differences in the median of mRS (p = 0.262). Conclusions: Although more evidence is needed, a significant improvement in QOL was suggested after our OSA intervention, particularly in patients with good CPAP adherence.(AU)

Multiple events case-control study in a prospective cohort to identify systemic, cellular, and molecular biomarkers of obesity-induced accelerated aging in 30-years-olds: the ObAGE study protocol.

BACKGROUND: Aging is characterized by a progressive loss of capacities linked to fundamental alterations/damage in multiple cellular and molecular pathways. It is the most significant risk factor for all non-communicable diseases (NCDs). Another contributing factor to the rise in NCDs is obesity. It has been suggested that obesity not only accelerates the onset of metabolic imbalances but also decreases lifespan and impacts cellular and molecular processes in a manner similar to aging. Obesity might accelerate the pace of aging. Guided by a lifecourse approach, we will explore how exposure to obesity in critical developmental stages disrupt homeostatic resilience mechanisms that preserve physiological integrity, inducing an early expression of aging phenotypes. Also, we will determine whether exposure to early psychosocial adversity influences vulnerability to obesity as a risk factor for accelerated aging. METHODS: Multiple events case-control study embedded in a prospective cohort of Chileans at 30-31y, 50% females, of low- to-middle socioeconomic status, who participated in nutrition research since birth. At 23y, 25% had obesity and cardiometabolic risk was high. We will use a multi-layer approach including: anthropometric assessment; DXA scan for body composition; abdominal ultrasound of the liver; stool samples collection and sequencing of the ribosomal RNA 16S gene to characterize the gut microbiome; determination of age-related pro-inflammatory cytokynes and anti-inflammatory miokynes. For the first time in Chile, we will address age-related epigenetic changes using the Horvath´s epigenetic clock. In a subset we will conduct a controlled physical challenge to characterize physical resilience (autophagy). DISCUSSION: ObAGE is in an excellent position to: approach aging as a process whose expression involves multiple factors from the early stages of a person's life; understand how longitudinal changes in health trajectories impact the biological mechanisms of aging; identify potential resilience mechanisms that help prevent unhealthy aging. Because SLS participants are still young, our research setting combined with advanced scientific techniques may identify individuals or groups at risk of early onset health issues. Results from ObAGE may pave the way to address the contribution of obesity to aging through lifespan from cells to systems and might be instrumental to developing interventions to improve health span in the Chilean population. TRIAL REGISTRATION: The proposed study does not consider any health care intervention on human participants.

Genetic determinants of BMI from early childhood to adolescence: the Santiago Longitudinal Study.

BACKGROUND: While the genetic contribution to obesity is well established, few studies have examined how genetic variants influence standardized body mass index Z-score (BMIz) in Hispanics/Latinos, especially across childhood and adolescence. OBJECTIVES: We estimated the effect of established BMIz loci in Chilean children of the Santiago Longitudinal Study (SLS). METHODS: We examined associations with BMIz at age 10 for 15 loci previously identified in European children. For significant loci, we performed association analyses at ages 5 and 16 years, for which we have smaller sample sizes. We tested associations of unweighted genetic risk scores (GRSs) for previously identified tag variants (GRS_EUR) and from the most significant variants in SLS at each locus (GRS_SLS). RESULTS: We generalized five variants at age 10 (P < 0.05 and directionally consistent), including rs543874 that reached Bonferroni-corrected significance. The effect on BMIz was greatest at age 10 for all significant loci, except FTO, which exhibited an increase in effect from ages 5 to 16. Both GRSs were associated with BMIz (P < 0.0001), but GRS_SLS explained a much greater proportion of the variation (13.63%). CONCLUSION: Our results underscore the importance of conducting genetic investigations across life stages and selecting ancestry appropriate tag variants in future studies for disease prediction and clinical evaluation.

Breastfeeding as the sole source of milk for 6 months and adolescent bone mineral density.

Little is known regarding the relationship between early life factors and bone mineral density (BMD). We found a positive association between breastfeeding for at least 6 months, without formula supplementation, and whole body adolescent BMD z-score. INTRODUCTION: The aim of the study is to assess the role of breastfeeding BF on adolescent bone mineral density (BMD) in a cohort prospectively followed since infancy. METHODS: We studied 679 participants from an infancy iron deficiency anemia preventive trial in Santiago, Chile, followed to adolescence. Breast and bottle feeding were ascertained weekly from 4 to 12 months. At 16 years, whole body BMD was assessed by DEXA. Using linear regression, we evaluated associations between BF duration and BF as the sole source of milk and adolescent BMD z-score, adjusting for possible infancy, adolescent, and background confounders. RESULTS: Mean birth weight and length were 3.5 (0.3) kg and 50.7 (1.6) cm. For at least 6 months, BF was the sole source of milk for 26.3% and with supplementation for 36.7%. For 37%, BF was provided for less than 6 months. Mean 16-year BMD z-score was 0.25 (1.0). Covariates included male sex, birth length, and gestational age. BF as the sole source of milk ≥6 months, compared to BF < 6 months, was associated with higher adolescent BMD z-score adjusting for covariates (ß = 0.29, p < 0.05). Mixed BF was not significantly related to adolescent BMD z-score (ß = 0.06, p = 0.47). For every 30 days of BF as the sole source of milk, adolescent BMD z-score increased by 0.03 (p = 0.01). CONCLUSION: BF without formula supplementation for at least 6 months was associated with higher adolescent BMD z-score and a suggestive trend in the same direction for BMD suggests that exclusivity and duration of BF may play a role in adolescent bone health.

Prevalence of Sarcopenia in Community-Dwelling Chilean Elders According to an Adapted Version of the European Working Group on Sarcopenia in Older People (EWGSOP) Criteria.

BACKGROUND: Sarcopenia is the progressive loss of mass and skeletal muscle strength and has serious consequences on older people's health. The Chilean older population has a high life-expectancy, but the prevalence of functional dependence is also high. OBJECTIVE: To determine the prevalence of sarcopenia in Chilean older adults and its relationship with age, gender, and body mass index (BMI). DESIGN: Cross-sectional study. SETTING: Community. PARTICIPANTS: 1,006 non-disabled, community-dwelling subjects aged 60 years or older living in Santiago. MEASUREMENTS: Anthropometric measurements, handgrip strength, physical performance tests, and dual-energy-x-ray-absorptiometry (DXA) scan were performed. Sarcopenia was defined using the algorithm of the European Working Group on Sarcopenia in Older People (EWGSOP). Muscle mass was measured with DXA scan; skeletal muscle mass index (SMI) and hand dynamometry were defined with cut-off points obtained for the Chilean population. For a 3m walking speed we used the cut-off point of the EWGSOP definition. Nutritional status and obesity were defined according to World Health Organization standards. Association between sarcopenia and age, gender, BMI and lean/fat mass ratio was estimated by logistic regression models. RESULTS: The prevalence of sarcopenia was 19.1% (95%CI: 16.8%-21.8%), similar in men and women. There was an increasing trend of sarcopenia by age group and a decreasing trend with nutritional status. After logistic regression, sarcopenia was positively associated with age (OR=1.10; 95%CI:1.06-1.15) and falls (OR=1.83; 95%CI:1.07-3.15) and negatively associated with overweight (OR=0.31; 95%CI:0.16-0.59), obesity (OR=0.02; 95%CI:0.004-0.11), lean mass/fat mass ratio (OR=0.69; 95%CI:0.48-0.9997), knee height (OR=0.78; 95%CI:0.68-0.89) and calf circumference (OR=0.87; 95%CI:0.77-0.97). CONCLUSIONS: The total prevalence of sarcopenia was 19.1% increasing with age reaching 39.6% in people of 80 or more years of age. A negative association of sarcopenia with overweight, obesity and lean/fat mass ratio was observed. Although the high prevalence of obesity (35.9%), only 2% of obese people were sarcopenic.

Low muscle mass is associated with cardiometabolic risk regardless of nutritional status in adolescents: A cross-sectional study in a Chilean birth cohort.

BACKGROUND: Increased cardiometabolic risk (CMR) is documented in obese and non-obese adolescents with low muscular fitness. However, the association of low muscle mass (LMM) with CMR, independent of weight status, has not been examined. We analyzed the relationship of LMM with CMR in adolescents, regardless of their weight status. MATERIALS AND METHODS: Observational study in 660 adolescents. BMI, waist circumference (WC), arterial blood pressures (ABP) were measured. Total fat mass (TFM), total lean tissue (TLT), and appendicular skeletal muscle mass (ASM) were estimated (DXA). Fasting lipid profile, glucose, and insulin were measured. HOMA-IR was estimated. Metabolic Syndrome (MetS) was diagnosed (AHA/NHLBI/IDF). ROC analysis was performed to find the optimal cutoffs of TLT percentage for MetS diagnosis. Values below these cutoffs defined LMM. ANCOVA examined the association of LMM with selected cardiometabolic biomarkers. RESULTS: In both sexes, TLT showed better sensitivity and specificity than ASM for MetS diagnosis. In males and females, TLT of 66.1% and 56.3%, respectively, were the optimal cutoff for MetS diagnosis. In the sample, 17.3% of males and 23.7% of females had LMM. In both sexes, adolescents with LMM had significantly higher values of WC, ABP, TG, TC/HDL, HOMA-IR, and MetS z-score than non-LMM participants. Adolescents with LMM, regardless nutritional status, had significantly increased values of MetS z-score, ABP, TG, TC/HDL-chol, and HOMA-IR than non-obese non-LMM adolescents. Adolescents having both obesity and LMM had the unhealthiest CMR profile. CONCLUSION: In adolescents, LMM was associated with higher CMR, regardless of nutritional status. In obese adolescents, LMM increased obesity-associated CMR.

Mini Nutritional Assessment Short-Form: Validation in Five Latin American Cities. SABE Study.

OBJECTIVES: To validate the short-form of the MNA (MNA-SF) and the cut-off point of 31 cm for calf circumference (CC) in older people in Latin America. METHODS: A cross-sectional study was conducted with 5,722 community-dwelling older subjects (range: 60-102 years) in Latin America´s five main cities: Sao Paulo (Brazil), Santiago (Chile), Havana (Cuba), Mexico DF (Mexico) and Montevideo (Uruguay). All participants underwent an interview, which included anthropometric measurements, completing the MNA and obtaining socio-demographic, nutrition and health information. The short-form of the MNA consists of only six questions from the original 18. It has two versions: one using body mass index (BMI) and the second using CC as a surrogate. Cohen's Kappa was calculated to assess the agreement between the MNA and the MNA-SF; diagnostic tests were performed, and Receiver-operating characteristic (ROC) curves were developed. Criterion-related validity was assessed in the Chilean sample. RESULTS: Both version of the MNA-SF showed high sensitivity and specificity with the MNA, showing good accuracy (0.88), although higher values were estimated for malnutrition and risk of malnutrition in the total sample by sex. The cut-off point of 31 cm for CC showed high sensitivity (74.6-94.4%), specificity (72.6-100%) and good area under the ROC curve (0.87-0.95) when compared with BMI. There was good agreement between MNA and both version of MNA-SF for identifying persons with malnutrition or a risk of malnutrition in the five cities (Kappa coefficient: 0.6193-0.7852). CONCLUSION: Both versions of the MNA-SF are population-screening tools of easy and fast application, with good accuracy for assessing malnutrition and risk of malnutrition in Latin American older people.

Healthy Chilean Adolescents with HOMA-IR ≥ 2.6 Have Increased Cardiometabolic Risk: Association with Genetic, Biological, and Environmental Factors.

OBJECTIVE: To determine the optimal cutoff of the homeostasis model assessment-insulin resistance (HOMA-IR) for diagnosis of the metabolic syndrome (MetS) in adolescents and examine whether insulin resistance (IR), determined by this method, was related to genetic, biological, and environmental factors. METHODS: In 667 adolescents (16.8 ± 0.3 y), BMI, waist circumference, glucose, insulin, adiponectin, diet, and physical activity were measured. Fat and fat-free mass were assessed by dual-energy X-ray absorptiometry. Family history of type 2 diabetes (FHDM) was reported. We determined the optimal cutoff of HOMA-IR to diagnose MetS (IDF criteria) using ROC analysis. IR was defined as HOMA-IR values above the cutoff. We tested the influence of genetic, biological, and environmental factors on IR using logistic regression analyses. RESULTS: Of the participants, 16% were obese and 9.4 % met criteria for MetS. The optimal cutoff for MetS diagnosis was a HOMA-IR value of 2.6. Based on this value, 16.3% of participants had IR. Adolescents with IR had a significantly higher prevalence of obesity, abdominal obesity, fasting hyperglycemia, and MetS compared to those who were not IR. FHDM, sarcopenia, obesity, and low adiponectin significantly increased the risk of IR. CONCLUSIONS: In adolescents, HOMA-IR ≥ 2.6 was associated with greater cardiometabolic risk.

Adherence to a physical activity intervention among older adults in a post-transitional middle income country: a quantitative and qualitative analysis.

OBJECTIVES: The effectiveness of community level interventions depends to a great extent on adherence. Currently, information on factors related to adherence in older adults from developing countries is scarce. Our aim was to identify factors associated to adherence to a physical activity intervention in older adults from a post-transitional middle income country. DESIGN, SETTING AND PARTICIPANTS: Using a combination of quantitative and qualitative methods we studied 996 older Chilean subjects (65-67.9 years at baseline) with low to medium socioeconomic status from 10 health centers randomized to receive a physical activity intervention as part of the CENEX cluster trial (ISRCTN48153354). MEASUREMENTS: Using a multilevel regression model, the relationship between adherence (defined a priori as attendance at a minimum of 24 physical activity classes spread over at least 12 months) and individual, intervention-related and contextual factors was evaluated. We also conducted 40 semi-structured interviews with older adults (n=36) and instructors (n=4). Transcripts of the interviews were analyzed using content analysis to identify barriers and facilitators to adherence. RESULTS: Adherence to physical activity intervention was 42.6% (CI 95% 39.5 to 45.6). Depression, diabetes mellitus, percentage of impoverished households and rate of arrests for violent crimes in the neighborhood predicted less adherence (p<0.05) while being retired, participation in physical activity prior to the intervention, and green areas per habitant were positively associated with adherence (p<0.05). The qualitative interviews identified three primary barriers to adherence: current health problems, lack of time due to commitments for caring for family members, and being employed, and two primary facilitators to adherence: the health benefits attributed to the intervention and the opportunity the classes provided for social interaction with others. CONCLUSION: In order to enhance effectiveness of community exercise interventions, strategies to improve participation should be targeted to older adults from deprived areas and those with psychological and medical conditions.

Obesity and eating behaviour in a three-generation Chilean family with carriers of the Thr150Ile mutation in the melanocortin-4 receptor gene

It has been proposed that functional mutations in the melanocortin 4 receptor(MC4R) gene have an important impact in body mass index, being considered as amajor susceptibility gene for obesity. A number of mutations have been reported inthe MC4R gene in subjects from different countries and ethnic groups. However, noreports of MC4R mutations are have been published for South American populations.In this study, DNA samples of thirty-two unrelated obese women of Chileanorigin were examined to search for genetic variants in the single exon of the genethrough the use of single strand conformational polymorphism techniques and directsequencing, leading to the identification of a Thr150Ile mutation in heterozygous status.The evaluation of family relatives of the index case for this mutation using PCRRFLPanalysis, identified two additional carriers in a three-generation family. Obesity,eating behavior and body composition phenotypes in this family revealed a possiblerelation of this variant with obesity in the presence of reduced penetrance.According to our knowledge, this is the first report of MC4R mutations in SouthAmerican populations (AU)

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Obesity and eating behaviour in a three-generation Chilean family with carriers of the Thrl50Ile mutation in the melanocortin-4 receptor gene.

It has been proposed that functional mutations in the melanocortin 4 receptor (MC4R) gene have an important impact in body mass index, being considered as a major susceptibility gene for obesity. A number of mutations have been reported in the MC4R gene in subjects from different countries and ethnic groups. However, no reports of MC4R mutations are have been published for South American populations. In this study, DNA samples of thirty-two unrelated obese women of Chilean origin were examined to search for genetic variants in the single exon of the gene through the use of single strand conformational polymorphism techniques and direct sequencing, leading to the identification of a Thr150Ile mutation in heterozygous status. The evaluation of family relatives of the index case for this mutation using PCR-RFLP analysis, identified two additional carriers in a three-generation family. Obesity, eating behavior and body composition phenotypes in this family revealed a possible relation of this variant with obesity in the presence of reduced penetrance. According to our knowledge, this is the first report of MC4R mutations in South American populations.

Lack of association between the fatty acid binding protein 2 (FABP2) polymorphism with obesity and insulin resistance in two aboriginal populations from Chile.

The aim of this study was to assess the frequency of fatty acid binding protein 2 (FABP2) Ala54Thr genetic polymorphism and to evaluate its association with obesity and insulin resistance in Chilean aboriginal populations. A sample of 96 urban Aymara and 111 urban Mapuche subjects aged 20-80 years were recruited for this cross-sectional study. Glucose, insulin and lipid profile were measured in fasting plasma samples. Insulin resistance was estimated through the HOMA-IR model. FABP2 Ala54Thr genotypes were determined by PCR followed by RFLP analysis. The allele frequency of Thr54 variant was estimated as 18.2% in Aymara subjects, which is one of the lowest reported to date. The corresponding frequency in Mapuche subjects was 31.9% (p<0.002). Regarding genotype-phenotype associations, no significant differences were found in any of the anthropometric or metabolic variables according to Ala54Thr genotypes. After adjustment by BMI and metabolic variables through a logistic regression analysis, the association of the FABP2 polymorphism with ethnic group persisted (Mapuche group: OR=2.37, 95% CI 1.319-4.277, p=0.004) It is unlikely that Ala54Thr polymorphism of the FABP2 gene plays a relevant role in obesity and insulin resistance in Chilean ethnic groups.

Adiposity and bone mineral density of Chilean elderly women in relation to toll-like receptor 4 gene polymorphisms.

BACKGROUND: It has been proposed that the toll-like receptor-4 gene (TLR4) may participate in the development of obesity and osteoporosis, in addition to its well-known role in the immune response. On the other hand, the adipose tissue of obese subjects shows an increased expression of the proinflammatory cytokine, tumour necrosis factor-alpha (TNF-alpha), which is released after lipopolysaccharide recognition by TLR4. AIM: To estimate the allele/genotype frequencies and linkage disequilibrium measures of Asp299Gly and Thr399Ile polymorphisms of the TLR4 gene in the Chilean elderly population, and to screen for their association with variables related to adiposity or bone mineral density. SUBJECTS AND METHODS: The study group included 227 unrelated Chilean elderly women (61-95 years) recruited from a population-based sample. Adiposity and bone mineral density measures were obtained using dual-energy X-ray absorptiometry. RESULTS: The allele frequencies for TNF -308A, TLR4 299Gly and TLR4 -399Ile were 9.3%, 4.6% and 4.4%, respectively, with Asp299Gly and Thr399Ile being in strong linkage disequilibrium (D' = 0.88). Although seriously restricted by the low frequency of the allele variants, no relevant association between genotypes and adiposity-related variables were found. Likewise, no significant association between osteoporosis status (categorized as osteoporosis, osteopenia or normal status) with TLR4 Asp299Gly or TNF -308G>A genotypes was found. CONCLUSION: It is unlikely that TLR4 Asp299Gly, TLR4 Thr399Ile or TNF -308G>A polymorphisms have a major influence on adiposity, bone mineral density or osteoporosis status in Chilean elderly women.

Anthropometric measurements in the elderly population of Santiago, Chile.

OBJECTIVE: There are few studies on anthropometry and nutritional status in large and representative samples of elderly populations in Chile and South America. We describe age and sex differences in weight, height, body mass index, knee height, waist circumference, midarm circumference, triceps skinfold thickness, arm muscle area, and calf circumference in Chilean elderly subjects. METHODS: This was a population-based, cross-sectional study. A total of 1220 elderly persons (819 women and 411 men; age range, 60-99 y) were recruited in the city of Santiago (Chile) through a probabilistic sampling procedure carried out from October to December 1999. RESULTS: Men were significantly heavier and taller than women in all age groups, whereas body mass index values were significantly higher in women than in men. All anthropometric variables showed a decrease in average values with aging in men and women. The apparent negative slopes for the decline in average values of body weight with aging was of greater magnitude in women than in men (-0.42 kg/y and -0.54 kg/y in male and female subjects, respectively). However, significant age x sex interaction was detected only for triceps skinfold thickness. In women, quadratic terms for age provided a significantly better fit than did the simple linear model for the association between age and weight, body mass index, waist circumference, triceps skinfold thickness, calf circumference, or midarm circumference. CONCLUSION: These observations indicated that body weight changes associated with aging might be more severe in Chilean women than in men, probably determining a differential pattern of lean and fat mass loss.

Anticuerpos anti-albúmina bovina (BSA) en niños diabéticos tipo 1 recién diagnosticados y su asociación con lactancia materna y exposición a leche de vaca / Bovine serum albumin (BSA) antibodies in children with recently diagnosed type 1 diabetes with breast feeding and milk exposition

BACKGROUND: Environmental and genetic factors (viruses, toxins and diet) are involved in the aetiology of type 1 diabetes. Among the dietary factors, the role of breast feeding and exposure to cow's milk proteins deserve special attention. AIM: To determine the anti-BSA-IgG levels in type 1 diabetic children and to analyse the possible association with breast feeding duration, exposure to cow's milk and beta pancreatic auto-antibodies. PATIENTS AND METHODS: Blood samples were collected from 161 diabetic children and 144 controls to measure anti-BSA-IgG level, GAD65, IA-2 and ICA autoantibodies. All children answered a questionnaire about dietary habits during infancy. RESULTS: anti-BSA-IgG was positive (using a cut off point of 25.6 ng/ml) in 98 per cent of diabetic children and 0 per cent of the control population. The length of breast feeding or early exposure to cow's milk did not influence the concentration of anti-BSA-IgG. Positive BSA titers did not increase the beta pancreatic reactivity (ICA+, GAD+, IA2+). CONCLUSIONS: Our data confirm the high frequency of anti-BSA-IgG among diabetic children. However, a specific role in the immunological process of type 1 diabetes cannot be attributed to this protein.

Trends in overweight and obesity prevalence in Chilean children: comparison of three definitions.

OBJECTIVE: To compare trends in prevalence of overweight and obesity among Chilean children using three different criteria. METHODS: Descriptive cross-sectional school-based study to analyse these trends in 6-y-old boys and girls who entered first grade in 1987, 1990, 1993, 1996 and 2000. Gender-specific prevalence of overweight and obesity were determined with three criteria: weight for height (W-H) Z-scores compared to NCHS 1977; present reference used by the Ministry of Health; and body mass index (BMI) compared to the revised US CDC Growth Charts with cut-off values of P85-95 and P-95 and IOTF reference with cut-offs extrapolated from an adult BMI of 25 and 30. RESULTS: The prevalence of overweight determined by W-H (WHO) increased from 15% in 1987 to 20% in 2000 for boys and from 17.2 to 21.8% for girls. With BMI-CDC, the increase was from 13.2 to 19.2% for boys and 12 to 18.5% for girls. With BMI-IOTF, rates were very similar. Prevalence of obesity using W-H (WHO) increased from 6.5% in 1987 to 17% in 2000 for boys and from 7.8 to 18.6% for girls. Using BMI-CDC, the increase was from 5.1 to 14.7% for boys and from 4 to 15.8% for girls; using BMI-IOTF prevalence estimates were much lower. CONCLUSIONS: Obesity prevalence in children has increased over time, and trends are similar independent of criteria. The reference used to define prevalence is important since it provides different estimates. Policy makers should be aware that a spurious drop in prevalence may appear if the IOTF reference is compared to the other criteria.

Transmission of high-risk HLA-DQB1 alleles in Chilean type 1 diabetic patients and their parents: stratification by the presence of ICA or GAD65 autoantibodies.

AIM: The purpose of this study was to assess whether the transmission of DQB1*0201 and DQB1*0302 alleles from heterozygous parents to Chilean type 1 diabetic patients depends on the presence of antibodies such as glutamic acid decarboxilase (GAD65) or Islet Cell (ICA) autoantibodies in the affected case. MATERIAL AND METHODS: A study of incident type 1 diabetic cases and parents was carried out in Santiago, Chile during 1997-98. The use of the case-parental design eliminates the possibility that case-controls differences are due to selection of controls whose genetic backgrounds differ systematically from those of cases. HLA-DQB1 polymorphisms were determined in cases and parents from n = 83 families using polymerase chain reaction and oligonucleotide dot-blot analysis. Detection of GAD65 antibodies was performed using a simple radio-binding asssay. Conventional ICA were detected by indirect immunofluorescence. RESULTS: Transmission disequilibrium test indicate a strong association between DQB1*0201 and DQB1*0302 and type I diabetes. When comparing the two subsets of families defined by having an affected child tested negative or positive for GAD65 antibodies (39 and 44 case-parent trios respectively) the probability of transmission of DQB1*0201 significantly differed between such strata (p-value=0.025). The pattern of transmission of DQB1*201 allele was also significantly different in the two subsets of families defined by ICA-or ICA+ cases (23 and 60 trios respectively) (p-value = 0.028). No differences were found in the transmission of DQB1*0302 allele in the different strata defined by the autoimmunity status of the proband. CONCLUSION: Our results reveal that DQB1*0201 allele may display distinct associations with type I diabetes depending on the autoimmunity to ICA and GAD65 autoantibodies.

[Auto-antibody profile and breast feeding in type 1 diabetic patients]. / Perfil de auto-anticuerpos y lactancia materna en pacientes diabéticos tipo 1.

BACKGROUND: Islet cell-specific autoantibodies such as islet cell antibody (ICA), antiinsulin (IAA), anti-glutamic acid decarboxylase (GAD) and anti-tyrosine phosphatase (IA2) can be present in patients with type I diabetes. Breast feeding duration and the early exposure to milk substitutes are environmental factors associated to etiology of type 1 diabetes. AIM: To study the frequency of the anti-GAD, anti-IA-2 e ICA antibodies in Chilean type 1 diabetic patients and determine the possible modulator effect of the breast feeding. PATIENTS AND METHODS: One hundred thirty four type 1 diabetic patients, aged one to 15 years old, were studied at the moment of their diagnosis. Patients were classified according to the duration of exclusive breast feeding. IA-2 and GAD were determined by radio immuno assay and ICA by means of indirect immunofluorescence. RESULTS: Subjects with three months or less and those with more than three months of breast feeding were positive for ICA in 78.8 and 90.6% of cases respectively, for GAD in 75 and 54.6% of cases respectively (p = 0.024) and for IA-2 in 73 and 43.8% of cases respectively (p = 0.001). All three antibodies were positive in 53.9 and 21.8% of children with less or more than three months of breast feeding (p = 0.001). CONCLUSION: Both IA-2 and GAD antibodies are less frequently positive in type 1 diabetic patients who have been breast fed for more than three months. These findings suggest a possible attenuating role of exclusive breast feeding on pancreatic aggression events in patients with type 1 diabetes.

Nutrition transition in Latin America: the case of Chile.

The nutritional situation of Latin America is changing rapidly from one characterized by underweight and stunting to one where chronic diseases such as cancer, cardiovascular disease, and type 2 diabetes are increasingly prevalent. In Chile, under-nutrition has virtually disappeared, but rising obesity rates and risk factors for chronic diseases indicate the need to modify existing programs and emphasize prevention of diet-related chronic diseases.