RESUMO
OBJECTIVE: This work aimed to parse out the role of changing environments on body composition, total energy expenditure, and physical activity in the Mexican Pima, a population experiencing rapid industrialization. METHODS: Using doubly labeled water, we compared energy expenditure and physical activity in a longitudinal cohort of Mexican Pima (n = 26; female: 12) in 1995 and 2010. Body mass and composition were assessed by bioimpedance analysis. To determine the effects of environmental factors on body weight independent of age, we compared the 1995 longitudinal cohort with an age- and sex-matched cross-sectional cohort (n = 26) in 2010. RESULTS: Body mass, fat mass, and fat-free mass all significantly increased between 1995 and 2010. Despite a 13% average increase in body weight, weight-adjusted total daily energy expenditure decreased significantly. Measured physical activity levels also decreased between 1995 and 2010, after we adjusted for weight. CONCLUSIONS: Our results suggest that the recent industrialization of the Maycoba region in Sonora, Mexico, has contributed to a decrease in physical activity, in turn contributing to weight gain and metabolic disease among the Mexican Pima.
Assuntos
Composição Corporal , Metabolismo Energético , Humanos , Metabolismo Energético/fisiologia , Feminino , Masculino , México , Estudos Transversais , Adulto , Estudos Longitudinais , Índice de Massa Corporal , Pessoa de Meia-Idade , Atividade Motora/fisiologia , Peso Corporal , Exercício Físico/fisiologia , Aumento de Peso/fisiologia , Adulto Jovem , Meio Ambiente , Obesidade/epidemiologiaRESUMO
BACKGROUND: The medical body composition analyzer (mBCA) incorporates advances in multifrequency technology and has been validated using a 4-compartment (4C) model in adults but not in youths aged <18 y. OBJECTIVES: This study aimed to formulate a 4C model based on 3 reference methods and develop and validate a body composition prediction equation for the mBCA in youths aged 10â17 y. METHODS: The body density of 60 female and male youths was measured by air displacement plethysmography, total body water by deuterium oxide dilution, and BMC by DXA. Data from the equation group (n = 30) were used to formulate a 4C model. The all-possible-regressions method was used to select variables. The model was validated in a second cohort (n = 30) in a random split design. The accuracy, precision, and potential bias were evaluated by the Bland and Altman procedure. RESULTS: Mean age, weight (W), height (H), waist circumference, and z-score of BMI were 13.6 ± 2.3 y, 54.5 ± 15.5 kg, 156 ± 11.9 cm, 75.5 ± 10.9 cm, and 0.70 ± 1.32 z, respectively. The prediction equation was as follows: FFM in kg (FFMkg) = ([0.2081] ∗ [W] + [0.8814] ∗ [H2cm/RΩ] + [0.2055 ∗ XcΩ])-15.343; R2 = 0.96; standardized root-mean-square error (SRMSE) = 2.18 kg. FFM did not differ between the 4C method (38.9 ± 12.0 kg) and the mBCA (38.4 ± 11.4 kg) (P > 0.05). The relationship between these 2 variables did not deviate from the identity line, was not significantly different from 0, and the slope was not significantly different from 1.0. In the precision prediction model of mBCA, the R2 value was 0.98 and SRMSE was 2.1. No significant bias was found when regressing differences between methods and their means (P = 0.08). CONCLUSIONS: The equation for the mBCA was accurate, precise, had no significant bias, had substantial strength of agreement and could be used in this age group when subjects were preferentially within the constraints of a specified body size.
Assuntos
Tecido Adiposo , Composição Corporal , Adulto , Humanos , Masculino , Feminino , Adolescente , Óxido de Deutério/metabolismo , Tecido Adiposo/metabolismo , Pletismografia , Impedância Elétrica , Absorciometria de Fóton , Reprodutibilidade dos Testes , Água CorporalRESUMO
BACKGROUND: Ultra-processed foodstuffs have been replacing traditional beans with tortillas in the Mexican diet in the last decades. Therefore, scientific support is needed to promote a return to good-quality traditional dishes. OBJECTIVES: This study aims to evaluate the amino acid digestibility and score of pinto beans (Phaseolus vulgaris) consumed with corn tortillas and guacamole in adults using the dual-tracer method. METHODS: The pinto beans were intrinsically labeled using 250 mL of 2H2O (99.8%) per 19 L pot with 3 plants. A paste of cooked beans on toasted corn tortillas and guacamole topping were administered to 3 male and 3 female adults (21-25 years old; BMI, 19-23.5 kg/m2). The protocol was plateau feeding given along with U-[13C]-spirulina protein to evaluate indispensable amino acid (IAA) digestibility using the dual-tracer method. Blood samples were taken in the plateau state. The digestibility of each IAA of the bean protein was calculated by the ratio of its enrichment in the beans to the spirulina in the meal and its appearance in plasma collected in the plateau state, as a percentage corrected by spirulina digestibility. Additionally, the digestible IAA score (DIAAS) was calculated. RESULTS: The 2H enrichment of IAA in the pinto beans was 471 parts per million excess. The isotopic enrichment of 2H and 13C in IAA at 5-8 hours presented plateau states with mean CVs of 12.2% and 13.3%, respectively. The mean digestibility of IAA from pinto beans was 77% ± 1.6%, with the lowest value for threonine. The DIAAS calculated with respect to the pattern requirement for children older than 3 years, adolescents, and adults was 83%, with methionine and cysteine being the limiting amino acids. CONCLUSIONS: A Mexican dish of pinto beans, tortillas, and guacamole is a good source of protein as evaluated in adults and could be promoted as a nutritious snack. The assay is registered with the Ethical Committee of the Centro de Investigación en Alimentación y Desarrollo, A.C. as CE/015/2019.
Assuntos
Aminoácidos , Zea mays , Adolescente , Adulto , Aminoácidos Essenciais , Criança , Pré-Escolar , Digestão , Feminino , Humanos , Íleo , Masculino , Adulto JovemRESUMO
BACKGROUND: Retinol isotope dilution (RID) and model-based compartmental analysis are recognized techniques for assessing vitamin A (VA) status. Recent studies have shown that RID predictions of VA total body stores (TBS) can be improved by using modeling and that VA kinetics and TBS in children can be effectively studied by applying population modeling ("super-child" approach) to a composite data set. OBJECTIVES: The objectives were to model whole-body retinol kinetics and predict VA TBS in a group of Mexican preschoolers using the super-child approach and to use model predictions of RID coefficients to estimate TBS by RID in individuals. METHODS: Twenty-four healthy Mexican children (aged 3-6 y) received an oral dose (2.96 µmol) of [13C10]retinyl acetate in corn oil. Blood samples were collected from 8 h to 21 d after dosing, with each child sampled at 4 d and at 1 other time. Composite data for plasma labeled retinol compared with time were analyzed using a 6-component model to obtain group retinol kinetic parameters and pool sizes. Model-predicted TBS was compared with mean RID predictions at 4 d; RID estimates at 4 d were compared with those calculated at 7-21 d. RESULTS: Model-predicted TBS was 1097 µmol, equivalent to â¼2.4 y-worth of VA; using model-derived coefficients, group mean RID-predicted TBS was 1096 µmol (IQR: 836-1492 µmol). TBS at 4 d compared with a later time was similar (P = 0.33). The model predicted that retinol spent 1.5 h in plasma during each transit and recycled to plasma 13 times before utilization. CONCLUSIONS: The super-child modeling approach provides information on whole-body VA kinetics and can be used with RID to estimate TBS at any time between 4 and 21 d postdose. The high TBS predicted for these children suggests positive VA balance, likely due to large-dose VA supplements, and warrants further investigation.
Assuntos
Vitamina A/farmacocinética , Carga Corporal (Radioterapia) , Criança , Pré-Escolar , Feminino , Humanos , Técnicas de Diluição do Indicador , Masculino , México , Estado Nutricional , Vitamina A/metabolismoRESUMO
Background and objectives: Body composition assessment can provide information associated with breast cancer patients' (BCP) prognosis, that can lead interventions to improve survival outcomes. The aim of this study was to evaluate the effect of an individualized nutrition intervention program on breast cancer patients using bioelectrical impedance vector analysis (BIVA). Materials and Methods: This is a pretest-posttest study in recently diagnosed nonmetastatic BCP undergoing antineoplastic treatment, free of co-morbidities and dietary supplementation. Body composition was assessed at baseline and 6 months after an individualized nutrition intervention program, by dual-energy X-ray absorptiometry and BIVA. According to BIVA, each participant was located in the bivariate tolerance ellipses for Mexican population (50%, 75%, and 95%). In clinical practice, the 50% and 75% ellipses are considered within normality ranges. Results: Nine nonmetastatic BCP completed the intervention and were included in the analysis. After the intervention, they decreased by 5.8 kg of body weight (IQR, 3-6; p < 0.05), 3.8 kg of fat mass (IQR, 0.1-4.2; p < 0.05), and 1.4 kg of fat-free mass (IQR, -0.1 to 4; p < 0.05) while appendicular skeletal muscle mass remained unchanged (-0.2 kg, IQR, -0.8 to 2.3; p = 0.4). Using BIVA at baseline, five participants were among the 50% and 75% ellipses, mainly located in the area corresponding to edema and low lean tissue, two in the cachexia quadrant and two in the athletic quadrant (≥95% ellipse). After 6 months of intervention, six out of nine participants were in the athletic quadrant and eight of nine BCP were above the 5° phase angle cut-off point. One patient initially presented cachexia (≥95% ellipse); at postintervention her vector changed to the 50% ellipse. Conclusions: An individualized nutrition intervention program designed for nonmetastatic BCP was effective to improve the nutritional status of BCP as assessed by BIVA, therefore BIVA can be a useful tool to monitor changes in nonmetastatic BCP body composition in research and clinical practice.
Assuntos
Neoplasias da Mama , Impedância Elétrica , Sarcopenia/diagnóstico , Absorciometria de Fóton , Adulto , Composição Corporal , Feminino , Humanos , Estado Nutricional , Sarcopenia/dietoterapia , Sarcopenia/patologiaRESUMO
The Diabetes Prevention Program (DPP) is effective for the prevention of type 2 diabetes by weight loss with diet and physical activity. However, there is little evidence as to whether this program could be translated into real-world clinical practice in Latin American countries. The objective of this work was to evaluate the effectiveness of the DPP for the management of overweightness and obesity at 6 and 12 months in clinical practice in Mexico. This was a non-controlled intervention study implemented in five public clinics in northern Mexico. Two hundred and thirty-seven adults aged 45.7 ± 9.9 years with a Body Mass Index (BMI) of 34.4 ± 5.4 kg/m2 received group sessions with an adaptation of the DPP, in addition to nutrition counseling. One hundred and thirty-three (56%) participants concluded the 6 month phase. They showed a significant weight loss, ranging from 2.76 ± 4.76 to 7.92 ± 6.85 kg (p ≤ 0.01) in the clinics. The intention-to-treat analysis showed a more conservative weight loss. Participant retention at the end of 12 months was low (40%). The implementation of the DPP in different public clinics in Mexico was effective in the management of obesity in the short term, but better strategies are required to improve participant retention in the long term.
Assuntos
Diabetes Mellitus Tipo 2/prevenção & controle , Estilo de Vida Saudável , Obesidade/terapia , Comportamento de Redução do Risco , Adulto , Aconselhamento , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/epidemiologia , Dieta Saudável , Exercício Físico , Feminino , Nível de Saúde , Humanos , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Obesidade/diagnóstico , Obesidade/epidemiologia , Educação de Pacientes como Assunto , Avaliação de Programas e Projetos de Saúde , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Redução de PesoRESUMO
BACKGROUND: Analysis of body composition is becoming increasingly important for the assessment, understanding and monitoring of multiple health issues. The body mass index (BMI) has been questioned as a tool to estimate whole-body fat percentage (FM%). Recently, a simple equation described as relative fat mass (RFM) was proposed by Woolcott & Bergman. This equation estimates FM% using two anthropometric measurements: height and waist circumference (WC). The authors state that due to its simplicity and better performance than BMI, RFM could be used in daily clinical practice as a tool for the evaluation of body composition. The aim of this study was to externally validate the equation of Woolcott & Bergman to estimate FM% among adults from north-west Mexico compared with Dual-energy X-ray absorptiometry (DXA) as an alternative to BMI and secondly, to make the same comparison using air displacement plethysmography (ADP), Bioelectrical Impedance Analysis (BIA) and a 4-compartment model (4C model). METHODS: Weight, height and WC were measured following standard procedures. The RFM index was calculated for each of the 61 participating subjects (29 females and 32 males, ages 20-37 years). The RFM was then regressed against each of the four body composition methods for estimating FM%. RESULTS: Compared with BMI, RFM was a better predictor of FM% determined by each of the body composition methods. In terms of precision the best equation was RFM regressed against DXA (y = 1.12 + 0.99 x; R2 = 0.84 p<0.001). Accuracy (represented by the closeness to the zero-intercept) was 1.12 (95% CI: -2.44, to 4.68) and thus, not significantly different from zero. For the rest of the methods, precision in the prediction of FM% was improved compared to BMI, with significant increases in the R2 and reduction of the root mean squared error (RMSE). However, the intercepts of each regression did not show accuracy since they were different from zero, for ADP: -9.95 (95%CI: -15.7 to -4.14), for BIA: -12.6 (95%CI: -17.5 to -7.74) and for the 4C model: -13.6 (95%CI: -18.6 to -8.60). Irrespectively, FM% measured by each of the body composition methods was higher for DXA than the other three methods (p<0.001). CONCLUSIONS: This external validation proved that the performance of the RFM equation used in this study to estimate FM% was more consistent than BMI in this Mexican population, showing a stronger correlation with DXA than with the other body composition methods.
Assuntos
Antropometria/métodos , Distribuição da Gordura Corporal , Índice de Massa Corporal , Absorciometria de Fóton/métodos , Tecido Adiposo/metabolismo , Adulto , Composição Corporal , Peso Corporal , Feminino , Humanos , Masculino , México , Circunferência da Cintura , Adulto JovemRESUMO
Prevalence of diabetes and obesity in Mexican Pima Indians is low, while prevalence in US Pima Indians is high. Although lifestyle likely accounts for much of the difference, the role of genetic factors is not well explored. To examine this, we genotyped 359 single nucleotide polymorphisms, including established type 2 diabetes and obesity variants from genome-wide association studies (GWAS) and 96 random markers, in 342 Mexican Pimas. A multimarker risk score of obesity variants was associated with body mass index (BMI; ß = 0.81 kg/m2 per SD, P = 0.0066). The mean value of the score was lower in Mexican Pimas than in US Pimas (P = 4.3 × 10-11 ), and differences in allele frequencies at established loci could account for approximately 7% of the population difference in BMI; however, the difference in risk scores was consistent with evolutionary neutrality given genetic distance. To identify loci potentially under recent natural selection, allele frequencies at 283 variants were compared between US and Mexican Pimas, accounting for genetic distance. The largest differences were seen at HLA markers (e.g., rs9271720, difference = 0.75, P = 8.7 × 10-9 ); genetic distances at HLA were greater than at random markers (P = 1.6 × 10-46 ). Analyses of GWAS data in 937 US Pimas also showed sharing of alleles identical by descent at HLA that exceeds its genomic expectation (P = 7.0 × 10-10 ). These results suggest that, in addition to the widely recognized balancing selection at HLA, recent directional selection may also occur, resulting in marked allelic differentiation between closely related populations.
Assuntos
Diabetes Mellitus Tipo 2/etnologia , Diabetes Mellitus Tipo 2/genética , Antígenos HLA/genética , Indígenas Norte-Americanos/genética , Obesidade/etnologia , Obesidade/genética , Alelos , Índice de Massa Corporal , Frequência do Gene , Estudo de Associação Genômica Ampla , Genótipo , Humanos , México , Polimorfismo de Nucleotídeo Único , Fatores de RiscoRESUMO
Assessments of whether children are thin (low body mass index for age) or overweight are based on body mass index (BMI for age and sex) charts published by the World Health Organization (WHO), the International Obesity Task Force (IOTF), and the US Centers for Disease Control and Prevention (CDC). We aimed to determine whether these charts indicated different prevalence of thinness and overweight (obesity included) in indigenous and non-indigenous school aged children from different regions and ethnic groups in Mexico. A probability proportional to size, cluster sampling method was employed in four regions of the country. We recruited 1,731 children aged 7.0-9.9 (507 indigenous from six ethnic groups and 1,224 non-indigenous). BMI was calculated according to age, and thinness and overweight classifications were compared according to cutoff values in the WHO, IOTF, and CDC references. The WHO reference generated the highest rates for thinness (12.5%) and overweight (30%) in children across regions and ethnic groups. The CDC reference estimated the lowest rates of thinness in children (5.5%), and the IOTF reference estimated the lowest rates of overweight (24.7%). Estimates of both thinness (8.3%) and overweight (13.4%) rates were lower in indigenous than non-indigenous groups (14.3% and 37.5%, respectively). The WHO BMI for age chart estimated higher rates of thinness and overweight in children compared to the CDC and IOTF charts. Because thinness as indicator of undernutrition status is relatively new, differences in body composition among indigenous and non-indigenous children may justify the need for more appropriate screening criteria to compare the growth status(AU)
La clasificación del estado nutricio de los niños con delgadez o con sobrepeso se realiza empleando el índice de masa corporal (IMC para la edad y el sexo) con las tablas de la OMS, IOTF y CDC. El objetivo de esta investigación fue determinar si estas referencias resultan en diferentes prevalencias de delgadez y sobrepeso (obesidad incluida) en niños escolares indígenas y no indígenas de diferentes regiones de México. Se empleó un muestreo por conglomerados en cuatro regiones del país. Se reclutaron 1,731 niños con edades entre 7,0-9,9 (507 indígenas de cinco grupos étnicos y 1,224 no indigenas) durante 2006 y 2008. El IMC se calculó y se clasificó como delgadez y sobrepeso con los puntos de corte sugeridos por las referencias internacionales. Cuando se compararon las clasificaciones, la referencia de OMS generó la prevalencia más alta de delgadez (12,5%) y sobrepeso (30%) en niños de todas las regiones y grupos étnicos. La referencia de los CDC estimó las prevalencias más bajas de delgadez (5,5%) y la referencia IOTF produjo las proporciones más bajas de sobrepeso (24,7%). Las proporciones de delgadez (8,3%) y sobrepeso (13,4%) fueron más bajas en niños indígenas que en los no indígenas (14.3% y 37.5%, respectivamente). La referencia de la OMS del IMC para la edad produjo las prevalencias más altas de delgadez y sobrepeso en comparación con los estándares de CDC y IOTF. Dado que la delgadez como indicador de desnutrición en niños es de uso reciente, las diferencias encontradas entre indígenas y mestizos pueden justificar el contar con mejores herramientas de tamizaje en estudios de crecimiento(AU)
Assuntos
Humanos , Masculino , Feminino , Magreza/etiologia , Índice de Massa Corporal , Obesidade/etiologia , DesnutriçãoRESUMO
Several studies suggest that the holiday season, starting from the last week of November to the first or second week of January, could be critical to gaining weight. This study aims to review the literature to determine the effects of the holidays on body weight. In studies of adults, a significant weight gain was consistently observed during this period (0.4 to 0.9 kg, p < 0.05). The only study in college students found an effect on body fat but not on weight (0.1 kg, p = 0.71). The only study found in children did not show an effect on BMI percentile (-0.4%, p > 0.05) during this period. Among individuals with obesity who attempt to lose weight, an increase in weight was observed (0.3 to 0.9 kg, significant in some but not in all studies), as well as increase in weight in motivated self-monitoring people (0.4 to 0.6%, p < 0.001). Programs focused on self-monitoring during the holidays (phone calls and daily mailing) appeared to prevent weight gain, but information is limited. The holiday season seems to increase body weight in adults, even in participants seeking to lose weight and in motivated self-monitoring people, whereas in children, adolescents, and college students, very few studies were found to make accurate conclusions.
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Obesidade/prevenção & controle , Aumento de Peso , Adulto , Fatores Etários , Criança , Férias e Feriados , Humanos , NarraçãoRESUMO
In Mexico, infants (0-2 years old) show the highest prevalence of vitamin A deficiency (VAD), measured by serum retinol concentrations. Thus, we consider that low vitamin A (VA) intake through breast milk (BM) combined with poor weaning practices are the main factors that contribute to VAD in this group. We combined the assessment of VA status in lactating women using BM retinol and a stable isotope 'dose-to-mother' technique to measure BM production in women from urban and agricultural areas. Infants' mean BM intake was 758 ± 185 mL, and no difference was observed between both areas (p = 0.067). Mean BM retinol concentration was 1.09 µmol/L, which was significantly lower for the agricultural area (p = 0.028). Based on BM retinol concentration, 57% of women were VAD; although this prevalence fell to 16% when based on fat content. Regardless of the VA biomarker used here, infants from the urban and agricultural areas cover only 66% and 49% of their dietary adequate intake from BM, respectively (p = 0.054). Our data indicate that VAD is still a public health concern in Mexico. Adopting both methods to assess VA transfer from the mother to the breastfed child offers an innovative approach towards the nutritional assessment of vulnerable groups.
Assuntos
Aleitamento Materno , Dieta , Lactação/metabolismo , Fenômenos Fisiológicos da Nutrição Materna , Leite Humano/química , Deficiência de Vitamina A/etiologia , Vitamina A/administração & dosagem , Adolescente , Adulto , Pré-Escolar , Óxido de Deutério , Feminino , Humanos , Técnicas de Diluição do Indicador , Lactente , México/epidemiologia , Mães , Estado Nutricional , Prevalência , Deficiência de Vitamina A/epidemiologia , Adulto JovemRESUMO
BACKGROUND: Breast cancer is the most deadly malignancy in Mexican women. Although treatment has improved, it may significantly affect bone mineral status in those who receive it. The aim of this study was to assess the impact of cancer treatment on bone mineral density (BMD) and bone mineral content (BMC), in patients with breast cancer and explore the interaction of menopausal status and clinical stage with cancer treatment on such changes. METHODS: A quasi-experimental design was applied with measurements before and after a chemotherapy treatment in 40 patients with primary diagnosis of invasive breast cancer. BMD and body composition measurements were taken by dual X-ray absorptiometry (DXA) and changes in these variables due to therapy were analyzed using mixed regression for repeated measurements. RESULTS: Significant loss was found in femoral neck and L2-L4 BMD (p < 0.001). Patients diagnosed with osteopenia or osteoporosis received calcium + vitamin D supplementation (600 mg/200 IU day). It showed a protective effect in the decrease of femoral neck BMD and total BMC. BMD loss in both femoral neck and L2-L4 BMD was higher in premenopausal women: 0.023 g/cm2 in femoral neck and 0.063 g/cm2 in L2-L4 (p < 0.001), while in postmenopausal women BMD loss was 0.015 g/cm2 in femoral neck and 0.035 g/cm2 in L2-L4 (p = 0.021 and p = 0.001 respectively). Change in lumbar spine BMD was prominent in premenopausal women with advanced clinical stage (IIB, IIIA, IIIB): 0.066 g/cm2 (p = 0.003). CONCLUSION: The antineoplastic breast cancer treatment with chemotherapy had a negative impact on BMD, in premenopausal women overall, although a differential effect was found according to clinical stage and calcium supplementation status.
Assuntos
Antineoplásicos/efeitos adversos , Densidade Óssea , Doenças Ósseas/etiologia , Doenças Ósseas/patologia , Neoplasias da Mama/complicações , Adulto , Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Biomarcadores Tumorais , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Feminino , Humanos , Menopausa , México , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Fatores de RiscoRESUMO
OBJECTIVE: The global epidemics of type 2 diabetes and obesity have been attributed to the interaction between lifestyle changes and genetic predisposition to these diseases. We compared the prevalences of type 2 diabetes and obesity in Mexican Pima Indians, presumed to have a high genetic predisposition to these diseases, to those in their non-Pima neighbors, both of whom over a 15-year period experienced a transition from a traditional to a more modern lifestyle. RESEARCH DESIGN AND METHODS: Prevalence of diabetes, impaired fasting glucose, impaired glucose tolerance, and obesity in Mexican Pimas (n = 359) and non-Pima Mexicans (n = 251) were determined in 2010 using methods identical to those used in 1995. RESULTS: During this 15-year period, age-adjusted diabetes prevalence was unchanged in Pima men (5.8% in 1995 vs. 6.1% in 2010) yet increased in non-Pima men from 0.0 to 8.6% (P < 0.05). Diabetes prevalence tended to increase in both Pima women (9.4 vs. 13.4%) and non-Pima women (4.8 vs. 9.5%). Age-adjusted prevalence of obesity increased significantly in all groups (6.6 vs. 15.7% in Pima men; 8.5 vs. 20.5% in non-Pima men; 18.9. vs 36.3% in Pima women; 29.5 vs. 42.9% in non-Pima women). CONCLUSIONS: Type 2 diabetes prevalence increased between 1995 and 2010 in non-Pima men, and to a lesser degree in women of both groups, but it did not increase in Pima men. Prevalence of obesity increased among Pimas and non-Pimas of both sexes. These changes occurred concomitantly with an environmental transition from a traditional to a more modernized lifestyle.
Assuntos
Diabetes Mellitus Tipo 2/epidemiologia , Indígenas Norte-Americanos/estatística & dados numéricos , Acontecimentos que Mudam a Vida , Obesidade/epidemiologia , Adulto , Estudos Transversais , Meio Ambiente , Feminino , Humanos , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Prevalência , Adulto JovemRESUMO
BACKGROUND: Although body fat percent (BF%) may be used for screening metabolic risk factors, its accuracy compared to BMI and waist circumference is unknown in a Mexican population. We compared the classification accuracy of BF%, BMI and WC for the detection of metabolic risk factors in a sample of Mexican adults; optimized cutoffs as well as sensitivity and specificity at commonly used BF% and BMI international cutoffs were estimated. We also estimated conditional BF% means at BMI international cutoffs. METHODS: We performed a cross-sectional analysis of data on body composition, anthropometry and metabolic risk factors(high glucose, high triglycerides, low HDL cholesterol and hypertension) from 5,100 Mexican men and women. The association between BMI, WC and BF%was evaluated with linear regression models. The BF%, BMI and WC optimal cutoffs for the detection of metabolic risk factors were selected at the point where sensitivity was closest to specificity. Areas under the ROC Curve (AUC) were compared among classifiers using a non-parametric method. RESULTS: After adjustment for WC, a 1% increase in BMI was associated with a BF% rise of 0.05 percentage points (p.p.) in men (P<0.05) and 0.25 p.p. in women (P<0.001). At BMI=25.0 predicted BF% was 27.6±0.16 (mean±SE) in men and 41.2±0.07 in women. Estimated BF% cutoffs for detection of metabolic risk factors were close to 30.0 in men and close to 44.0 in women. In men WC had higher AUC than BF% for the classification of all conditions whereas BMI had higher AUC than BF% for the classification of high triglycerides and hypertension. In womenBMI and WC had higher AUC than BF% for the classification of all metabolic risk factors. CONCLUSIONS: BMI and WC were more accurate than BF% for classifying the studied metabolic disorders. International BF% cutoffs had very low specificity and thus produced a high rate of false positives in both sexes.
Assuntos
Tecido Adiposo/anatomia & histologia , Adiposidade , Índice de Massa Corporal , Circunferência da Cintura , Adulto , Antropometria , Composição Corporal , Estudos Transversais , Feminino , Humanos , Hipertensão/complicações , Hipertrigliceridemia/complicações , Masculino , Síndrome Metabólica , México , Pessoa de Meia-Idade , Obesidade/epidemiologia , Fatores de Risco , Sensibilidade e EspecificidadeRESUMO
OBJECTIVE: To focus on the rationale and methods of the Maycoba Project. METHODS: Study population included Mexican Pima Indians (MPI) and Blancos aged ≥20-years, living in the village of Maycoba and surrounding area. Surveys in 1995 and 2010 included a medical history, biochemical and anthropomet- ric measurements. Additionally, socio- economic, physical activity, and dietary interviews were conducted. The 2010 study incorporated investigations on type 2 diabetes (T2D) and obesity-associated genetic alleles and human-envi- ronment changes. RESULTS: The study results are limited to demographic data and description of the eligible and ex- amined sample. CONCLUSIONS: This study may yield important information on T2D and obesity etiology in a traditional population exposed to environmental changes.
Assuntos
Diabetes Mellitus Tipo 2/etnologia , Indígenas Norte-Americanos , Obesidade/etnologia , Projetos de Pesquisa , Adulto , Antropometria , Metabolismo Basal , Censos , Diabetes Mellitus Tipo 2/etiologia , Dieta , Metabolismo Energético , Exercício Físico , Feminino , Inquéritos Epidemiológicos , Humanos , Masculino , Anamnese , México/epidemiologia , Pessoa de Meia-Idade , Obesidade/genética , Pesquisa Qualitativa , Adulto JovemRESUMO
OBJECTIVES: This study aimed to compare changes in whole body bone mineral density (wbBMD) during the first postpartum year in adolescent mothers with those of nulliparous adolescents. METHODS: The study included 21 adolescent mothers and 16 nulliparous adolescent non-indigenous Mexican women (State of Sonora) from a low income level. All mothers were assessed at 15 days (0.5 months), 3 months, and 6 months postpartum; 16 were measured at 12 months postpartum. Nulliparous adolescents were assessed in the same periods. Multiple regression models was used to assess adjusted associations of changes in wbBMD (by DPX-MD+ densitometer) with dietary calcium and physical activity assessments (estimated using pre-tested questionnaires), post menarche years, and number of breast feedings. RESULTS: At baseline, no differences were observed between nulliparous and adolescent mothers regarding age, post-menarche years, or BMD values. Changes in wbBMD of -0.56% and 0.77% were observed in mothers and nulliparous adolescents, respectively, after the first 3 months (P = 0.006). Changes in wbBMD in mothers were associated with number of breast feedings and changes in BMI. At 12 months postpartum, the BMD of adolescent mothers was similar to that of nulliparous adolescents. CONCLUSIONS: At 1 year postpartum, adolescent mothers exhibited BMD similar to those of nulliparous adolescents. This result is likely attributable to the breastfeeding practices adopted by mothers during late adolescence.
Assuntos
Densidade Óssea , Lactação , Absorciometria de Fóton , Adolescente , Feminino , Seguimentos , Humanos , Estudos Longitudinais , México , Período Pós-Parto , Fatores de TempoRESUMO
Vitamin A (VA) deficiency (VAD) continues to be a major nutritional problem in developing countries, including Central America. In Mexico, milk is a well-accepted vehicle for the administration of micronutrients, including VA, to preschoolers. Thus, we conducted a randomized, controlled, clinical trial to investigate the efficacy of daily consumption of 250 mL of VA-fortified milk (which provided 196 retinol equivalents/d) for 3 mo on VA stores in mildly to moderately VAD (serum retinol concentration 0.35-0.7 µmol/L) preschoolers who were not enrolled in a food assistance program. Twenty-seven mildly to moderately VAD children were randomly assigned based on screening measurements to either the intervention (n = 14) or control group (n = 13) (children in the control group did not receive placebo). All children in the control group and 79% (n = 11) of the children in the intervention group completed the study. The total body VA (TBVA) pool size was estimated using the deuterated retinol dilution technique before and after the intervention. After 3 mo, median changes in the serum retinol concentration for the intervention and control groups were 0.13 and -0.21 µmol/L, respectively (P = 0.009). Median changes in the TBVA stores were 0.06 and 0.01 mmol, respectively (P = 0.006) and estimated median changes in the liver VA concentration were 0.09 and 0.01 µmol/g, respectively (P = 0.002). The VA-fortified milk was well accepted among preschoolers and significantly increased TBVA stores, liver VA stores, and serum retinol concentration, indicating that it may be an effective means to ameliorate VAD in young Mexican children.
Assuntos
Alimentos Fortificados , Leite , Deficiência de Vitamina A/dietoterapia , Vitamina A/metabolismo , Vitamina A/uso terapêutico , Animais , Criança , Pré-Escolar , Deutério , Países em Desenvolvimento , Dieta/efeitos adversos , Feminino , Preferências Alimentares , Alimentos em Conserva , Humanos , Técnicas de Diluição do Indicador , Fígado/metabolismo , Masculino , México , Pacientes Desistentes do Tratamento , Índice de Gravidade de Doença , Vitamina A/administração & dosagem , Vitamina A/sangue , Deficiência de Vitamina A/sangue , Deficiência de Vitamina A/etiologia , Deficiência de Vitamina A/fisiopatologiaRESUMO
Objective. To evaluate the efficacy of the [(13)C]glucose breath test for measuring insulin resistance in Mexican adults with different glycemic states. Research Design and Methods. Fifty-eight adults underwent a [(13)C]glucose breath test with simultaneous measurement of total CO(2) production by indirect calorimetry, at baseline and 90 minutes after the ingestion of 15 g of dextrose and 25 mg of [(13)C]glucose. HOMA was used as a marker of insulin resistance. Results. We found an inverse correlation between HOMA and the breath test δ(13)CO(2) (), r = -0.41 (P = 0.001). After adjusting for total CO(2) production, correlations between HOMA and fasting glucose were less strong but remained significant. An ROC curve was constructed using δ(13)CO(2) () and HOMA values; the cut-off point was 9.99 δ(13)CO(2), corresponding to a sensitivity of 80.0 (95% CI: 51.9, 95.7) and a specificity of 67.4 (95% CI: 51.5, 80.9). Conclusions. The [(13)C]glucose breath test is a simple noninvasive procedure but was not sufficiently robust for an accurate diagnosis of insulin resistance. Our findings suggest that the test might be helpful in identifying individuals who are not IR, which in turn may contribute to improved diabetes prevention.
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Se evaluó la precisión y exactitud en la estimación de la grasa corporal (%) por absorciometría dual de rayos X (DXA Lunar-DPX-MD) comparado con el modelo de cuatro compartimentos (4C) en 32 púberes (F=16) de 9 a 14 años. El sesgo entre la DXA y el modelo de 4C fue de -3.5% de grasa (r=0.25; p=0.171) con un intervalo de confianza de -1.9 a -5.1 (p=0.050). Los límites de concordancia al 95% fueron de +5% a -12% de grasa. El coeficiente de correlación de concordancia fue de pc=0.85. La prueba de exactitud por análisis de regresión mostró que el intercepto y la pendiente de las estimaciones de grasa corporal por DXA fueron diferentes al modelo de 4C (p>0.05). La precisión evaluada con el valor de R2 mostró que la DXA explicó el 83% de la varianza de la grasa corporal por el modelo de 4C con un error de 4.1%. El error total como medida de exactitud fue de 5.6%. La exactitud grupal evaluada por análisis de varianza no mostró interacción entre el método (DXA-4C) y el análisis por separado del sexo, el estado puberal y la presencia de sobrepeso. No obstante, hubo efecto del método (p=0.043) en presencia de sobrepeso (p<0.001). En conclusión, los resultados muestran que el uso de la DXA comparado con el modelo de 4C no es equivalente en púberes mexicanos. Sin embargo, estos datos no limitan el uso de la DXA en estudios de composición corporal y su relación con anormalidades metabólicas.
The objective of this study was to validate the estimation of body fat (%BF) by DXA (Dual-Energy X-Ray AbsorciomDPX-MD) against the four compartment model (4C) of body composition in 32 Mexican pubertal girls and boys (aged 9 - 14y; F=16). The mean of the difference between DXA and 4C model was -3.5 %BF (p=0.171). The limits of agreement (95% ± 2 SD) were +5% to -12%BF. The precision of estimated limits of y the confidence intervals were -1.9% to -5.1%BF (P=0.050). The concordance correlation coefficient was pc= 0.85. The test of accuracy for coincidence of slop intercepts between DXA and the 4C model showed no coincidence (p< 0.05). The precision by R2 explained 83% of the variance (SEE, 4.1 %). The individual accuracy assess by the total error was 5.6%. The group mean accuracy by two way analysis of variance of body fat did not show interaction between method (DXA-4C model) and separate analysis of gender and overweight. However, there was an effect of method (p=0.043) in the presence of overweight (p<0.001). In conclusion, the estimation of percent of body fat by DXA was not precise and accurate in a group of Mexican children. However, results do not limit the utility of DXA for the measurements of body composition and its relation with health outcomes, especially in follow up studies.
Assuntos
Adolescente , Criança , Feminino , Humanos , Masculino , Absorciometria de Fóton , Tecido Adiposo , Composição Corporal , Água Corporal , Estudos Transversais , México , Obesidade/diagnósticoRESUMO
CONTEXT: Insulin resistance is a major risk factor for the development of type 2 diabetes in Pima Indians, a population with the highest prevalence of type 2 diabetes mellitus in the world. Their Mexican counterpart, living a traditional lifestyle in the mountains of Sonora, have at least 5 times less diabetes than the U.S. Pima Indians. OBJECTIVE: We evaluated whether Mexican Pima Indians had lower insulin resistance than U.S. Pima Indians. DESIGN AND PATIENTS: We compared fasting insulin and homeostasis model assessment for insulin resistance (HOMA-IR) in 194 Mexican Pima Indians (100 females, 94 males) and 449 U.S. Pima Indians (246 females, 203 males) with normal glucose tolerance from a cross-sectional study. Adjusted differences of log-transformed outcomes (fasting insulin and HOMA-IR) between groups were evaluated using multiple linear regression models and paired t test in a matched subset. RESULTS: Unadjusted fasting insulin and HOMA-IR were much lower in the Mexican Pima Indians than in their U.S. counterparts. After adjusting by obesity, age, and sex, mean (95% confidence interval) for fasting insulin was 6.22 (5.34-7.24) vs. 13.56 µU/ml (12.27-14.97) and for HOMA-IR 1.40 (1.20-1.64) vs. 3.07 (2.77-3.40), respectively, for Mexican Pima and U.S. Pima Indians. Results were confirmed in subset matched for age, sex, and body fat. CONCLUSION: Our results indicate that Mexican Pima Indians have lower insulin resistance in comparison with their genetically related U.S. counterparts, even after controlling for differences in obesity, age, and sex. This finding underscores the importance of lifestyle factors as protecting factors against insulin resistance in individuals with a high propensity to develop diabetes.