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Background: Predictive equations are the best option for assessing fat mass in clinical practice due to their low cost and practicality. However, several factors, such as age, excess adiposity, and ethnicity can compromise the accuracy of the equations reported to date in the literature., Objective: To develop and validate two predictive equations for estimating fat mass: one based exclusively on anthropometric variables, the other combining anthropometric and bioelectrical impedance variables using the 4C model as the reference method., Subjects/methods: This is a cross-sectional study that included 386 Hispanic subjects aged ≥60 with excess adiposity. Fat mass and fat-free mass were measured by the 4C model as predictive variables. Age, sex, and certain anthropometric and bioelectrical impedance data were considered as potential predictor variables. To develop and to validate the equations, the multiple linear regression analysis, and cross-validation protocol were applied., Results: Equation 1 included weight, sex, and BMI as predictor variables, while equation 2 considered sex, weight, height squared/resistance, and resistance as predictor variables. R 2 and RMSE values were ≥0.79 and ≤3.45, respectively, in both equations. The differences in estimates of fat mass by equations 1 and 2 were 0.34 kg and -0.25 kg, respectively, compared to the 4C model. This bias was not significant (p < 0.05)., Conclusions: The new predictive equations are reliable for estimating body composition and are interchangeable with the 4C model. Thus, they can be used in epidemiological and clinical studies, as well as in clinical practice, to estimate body composition in older Hispanic adults with excess adiposity., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

The densitometry method estimates body composition based on cadaver reference values, mainly the fat-free mass density value of 1.100 g/cm 3 . However, several changes in fat-free mass components by aging, ethnicity, and excess adiposity could influence their density and affect body composition estimations. The present study aimed to compare the mean fat-free mass component values in older Hispanic adults to cadaver reference values. This cross-sectional study included a sample of 420 subjects aged ≥60 yr from northern Mexico. Fat-free mass was determined by the four-compartment model using air displacement plethysmography, the deuterium dilution technique, and dual-energy X-ray absorptiometry for body density, aqueous and mineral fractions of body weight, respectively. A 1-sample t test was used to compare the fat-free mass density and aqueous, mineral, and residue fractions of fat-free mass from subjects in the study to the assumed cadaver reference values. The mean fat-free mass density value for the total sample of older Hispanic adults (1.096 ± 0.011 g/cm 3 ) was significantly (p < 0.001) lower than the assumed value of 1.100 g/cm 3 , except in obese older men. The mean aqueous fraction of fat-free mass (74.8 ± 3.3%) was higher than the assumed value of 73.8%, and the mean residue fraction of fat-free mass value was lower (18.3 ± 3.4%) than the reference value of 19.4%. Indeed, only the mean mineral fraction of fat-free mass value (6.8 ± 0.8%) was similar to the reference value. In the total sample, all characteristic mean fat-free mass values in these older Hispanic adults differed from cadaver reference values, except the mineral fraction of fat-free mass value., (Copyright © 2021 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.)

Type 2 diabetes (T2D) is a public health problem worldwide, and the main risk factor for its development is obesity. The Yaqui ethnic group of Sonora has serious obesity problems, resulting in an increased risk of T2D in its inhabitants. The objective of this study was to evaluate the effectiveness of a health promotion program on obesity parameters and cardiovascular risk factors in short- (6 months) and medium-term periods (12 months) in indigenous Yaquis of Sonora. The design is a translational clinical study of a single cohort with prepost intervention measurements in a sample of 93 subjects. The effectiveness of the program was evaluated by comparing obesity parameters, metabolic markers, and physical activity 6 and 12 months with those measured under basal conditions using a paired t -test or Wilcoxon rank-sum test. The short-term retention percentage was 58.0%. There was a decrease in body weight (Δ = -3.9 kg, p ≤ 0.05) and other obesity parameters, and an increase in physical activity and improvements in metabolic markers ( p ≤ 0.05) was observed. Similar findings were obtained for the medium-term period; body weight loss was also -3.9 kg ( p ≤ 0.05). The short and medium-term results of the program showed improvements in the obesity parameters and other cardiovascular risk factors of the participants. These results support the effectiveness of the program and its translation in this ethnic group., Competing Interests: The authors declare that there are no conflicts of interest for the publication of this article., (Copyright © 2020 Alejandro Arturo Castro-Juarez et al.)

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; β = 0.81 kg/m 2 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., (© 2018 John Wiley & Sons Ltd/University College London.)

Background: Mexico is a country that is rich in ethnicity and cultural diversity, divided into three well-defined socioeconomic, ecological, and epidemiological areas. However, we do not know the influence that these factors may have on body composition. Therefore, this study was designed to assess body composition and compare appendicular skeletal muscle mass (ASM) in older people from two areas of the country., Methods: This is a cross-sectional study that included 430 subjects ≥60 years of age from northwestern and central Mexico. Body composition, including ASM, was measured by dual-energy X-ray absorptiometry, while anthropometry, handgrip strength, demographic variables, health status/chronic conditions, and energy expenditure data were all included., Results: Men and women from the northwestern region had 5.9 kg and 3.8 kg more body fat, respectively, and 3.9 kg more as a group than their counterparts from central Mexico ( p ≤ 0.0001). While there were no significant differences across gender or region in terms of ASM, the older subjects from central Mexico had a significantly higher ASM index (ASMI) than the sample from the northwest. When ASM was adjusted for age, body weight, height, health status/chronic conditions, estimated energy expenditure, and demographic variables, the subjects from central Mexico had significantly higher adjusted mean values of ASM and ASMI than their counterparts from the northwest., Conclusion: Older people from two regions of Mexico had significantly different estimates of body composition. Our findings highlight the importance of regionalizing estimates of ASM and ASMI if they are to be used for diagnostic purposes. It is also important to emphasize that appendicular skeletal muscle mass, or the ASM index, should be adjusted for other associated biological variables.

Introduction: In order to reduce cardiovascular disease risk factors, a healthy diet must include dietary antioxidants from different sources (eg, Spirulina maxima ) and regular practice of exercise should be promoted. There is some evidence from animal studies that S. maxima and exercise decrease cardiovascular disease risks factors. However, very few studies have proved the independent or synergistic effect of S. maxima plus exercise in humans. This study attempts to address the independent and synergistic effects in overweight and obese subjects participating in a systematic physical exercise programme at moderate intensity on general fitness, plasma lipid profile and antioxidant capacity., Methods and Analysis: Using a randomised, double-blind, placebo-controlled, counterbalanced crossover study design, 80 healthy overweight and obese subjects will be evaluated during a 12-week isoenergetic diet accompanied by 4.5 g/day S. maxima intake and/or a physical systematic exercise programme at moderate intensity. Body composition, oxygen uptake, heart rate, capillary blood lactate, plasma concentrations of triacylglycerols, total, low-density and high-density lipoprotein cholesterol, antioxidant status, lipid oxidation, protein carbonyls, superoxide dismutase, catalase, glutathione, glutathione peroxidase, glutathione reductase and paraoxonase will be assessed., Ethics and Dissemination: This study and all the procedures have been approved by the Universidad Autonoma de Ciudad Juarez Bioethics Committee. Findings will be disseminated through peer-reviewed journals, national and international conferences., Trial Registration Number: ClinicalTrials.gov: NCT02837666., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

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., (© 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.)

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., Competing Interests: Statement The author(s) declare that they have no conflict interests.

Densitometry (Siri's and Brožek's equations), hydrometry (by the deuterium dilution technique), and dual-energy X-ray absorptiometry (DXA) are three methods for estimating body composition. However, because they are all based on certain assumptions, they may not be applicable to aged and obese subjects due to changes in their body composition. Hence, the validity of these "laboratory methods" could be affected in obese older people. The main aim was to assess the agreement between densitometry, hydrometry, and DXA with the 4-compartment (4C) model to estimate fat mass (FM) in obese older Hispanic-American adults. As secondary goals, we explored whether the bias in densitometry and hydrometry results could be improved by modifying the assumptions regarding fat-free mass (FFM) density and hydration factor (HF) values, respectively. In the case of DXA, we explored the factors that contribute to bias. This is a cross-sectional study based on a sample of 171 obese subjects aged ≥60 years from 3 regions of northern Mexico. Body composition was assessed by the 4C model as the reference method and by all three laboratory methods. Agreement of the latter with the 4C model was probed by Bland and Altman analysis, a paired sample t-test, and simple linear regression analyses. In addition, the mean FFM density estimated in this sample, and HF values (published previously) of 0.737 and 0.753 for obese older Hispanic-American men and women, respectively, were considered as ethnic- and gender-specific values. These values were used to modify the densitometric and hydrometric equations in order to improve their bias. Finally, we tested whether the hydration status and indirect markers of adiposity are contributing factors to the bias of DXA using multiple linear regression analysis. Siri's equation overestimated FM by 0.57 kg (p < 0.01), while Brožek's equation, hydrometry, and DXA underestimated it by 1.24 kg, 0.89 kg, and 0.79 kg (p < 0.01), respectively, compared to the 4C model. The bias in the densitometry and hydrometry results was eliminated by substituting the ethnic- and gender-specific values into the equations. Finally, we found that hip circumference contributes to the bias in DXA. The densitometry, hydrometry, and DXA methods are not interchangeable with the 4C model for assessing fat mass in obese, older Hispanic-American adults. The lack of agreement could indicate that the assumptions of each method do not apply to this population. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to determine associations between abdominal obesity (AOb) and the other components of metabolic syndrome (MetS) in young Mexicans in a cross-sectional survey completed during a 4 year period.Methods: This cross-sectional study reports on components and prevalence of MetS by using Alberti et al. (16) criteria, as well as association between AOb and elevated blood pressure (BP) of 2,993 Mexican university students, ages 17 to 25 years (66% women) from central and northern Mexico, over a 4-year survey (2010-2013).Results: The most prevalent MetS components in the total sample were low HDL-C concentration (43.6%) and AOb (41.1%). MetS prevalence was 11.8%, more men than women were classified with MetS (14.3% vs. 10.5%, p < 0.01). BP was the MetS component with the lowest prevalence (8.6%). A strong association between AOb and altered BP with in both men and women was found (OR 4.3, IC95% 2.5-7.4).Conclusions: Even BP was the component with the lowest prevalence, AOb was more strongly associated with it. This fact, could explain the prevalence of hypertension among young Mexican adults. [ABSTRACT FROM AUTHOR]

Age- and obesity-related body composition changes could influence the hydration factor (HF) and, as a result, body composition estimates derived from hydrometry. The aim of the present study was to compare the HF in older Hispanic-American adults to some published values. This cross-sectional study included a sample of 412 subjects, men and women, aged ≥60 years from northern Mexico. HF values were calculated based on the ratio of total body water-using the deuterium dilution technique-to fat-free mass, derived from the four-compartment model. The mean HF value for the total sample (0.748 ± 0.034) was statistically (p ≤ 0.01) higher than the traditionally assumed value of 0.732 derived from chemical analysis, the "grand mean" value of 0.725 derived from in vivo methods, and the 0.734 value calculated for older French adults via the three-compartment model. The HF of the older women did not differ across the fat mass index categories, but in men the obese group was lower than the normal and excess fat groups. The hydration factor calculated for the total sample of older Hispanic-American people is higher than the HF values reported in the literature. Therefore, the indiscriminate use of these assumed values could produce inaccurate body composition estimates in older Hispanic-American people. [ABSTRACT FROM AUTHOR]

Abstract: This cross-sectional study assessed the prevalence of malnutrition and several metabolic risk factors for cardiovascular disease in 287 apparently healthy older adults from Northwest Mexico. Also, the impact of overweight and obesity on metabolic risk factors was assessed. Nutritional status was determined using serum albumin levels and anthropometry. Vitamin status was also assessed. Metabolic risk factors for cardiovascular disease were evaluated. The prevalence of undernutrition was 15.3%. Also, vitamin E deficiency was common (18%). On the contrary, 44.9% of men and women were in overweight and 24% were obese. A 50.9% of the older adults had hypertension, 52.6% hypercholesterolemia (HC), 38.3% hypertriglyceridemia (HTG), 26.1% impaired fasting glucose and 26.1% impaired glucose tolerance (IGT). HC and low-density-lipoprotein-cholesterol (LDL-C) were significantly more prevalent in women than in men. Mean adjusted values of fasting glucose, high-density-lipoprotein-cholesterol (HDL-C), total cholesterol (TC)/HDL-C ratio ≥5, triglycerides (TG) and diastolic blood pressure (DBP) were significantly higher in subjects with body mass index (BMI)≥25.0kg/m2. Undernutrition, obesity and vitamin E deficiency, as well as several metabolic risk factors for cardiovascular disease coexisted in this studied group. Overweight and obesity were the most prevalent findings. BMI≥25kg/m2 was the common factor explaining most of the metabolic abnormalities. However, due to the sample size and the design of the study, the results must be seen with caution and cannot be generalized. [Copyright &y& Elsevier]