Changes in energy expenditure and physical activity over 15 years of environmental changes: The Maycoba project

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.

Body Composition in Youths Aged 10‒17 Years by Deuterium Oxide Dilution, Air Displacement Plethysmography, and DXA: Validation of the Medical Body Composition Analyzer Bioimpedance Device by a 4-Compartment Model

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 10‒17 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 (FFM_kg) = ([0.2081] ∗ [W] + [0.8814] ∗ [H²_cm/R_Ω] + [0.2055 ∗ Xc_Ω])-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.

Real-world efficacy of switching to bictegravir/ emtricitabine/tenofovir alafenamide in pretreated patients with triple therapy containing rilpivirine

Objetivo

Analizar la eficacia y tolerabilidad de la estrategia de cambio desde regímenes basados en rilpivirina (RPV) a bictegravir/emtricitabina/tenofovir alafenamida (B/F/TAF) en la vida real.

Métodos

Estudio unicéntrico, observacional y retrospectivo. Se seleccionaron pacientes que cambiaron de un régimen con RPV a B/F/TAF antes de febrero del 2020 analizándose los resultados después de 24 y 48 semanas. Se determinó el porcentaje que permanecía con carga viral indetectable, así como los cambios en linfocitos CD4+, parámetros metabólicos y función renal.

Resultados

Se incluyeron en el estudio 42 pacientes. 32 de los 35 (91,4%) que completaron las 48 semanas de seguimiento tenían carga viral indetectable. El recuento de linfocitos CD4+ permaneció estable a las 24 y a las 48 semanas. El tipo de análogos recibidos previamente no influyó en la respuesta

Conclusión

El cambio desde una triple terapia con RPV a B/F/TAF es una estrategia segura y eficaz en la vida real.

Systematic training in master swimmer athletes increases serum insulin growth factor-1 and decreases myostatin and irisin levels

During ageing, anabolic status is essential to prevent the decrease in quantity and quality of skeletal muscle mass (SMM). Exercise modulates endocrine markers of muscle status. We studied the differences of endocrine markers for muscle status in 62 non-sarcopenic Mexican swimmer adults aged 30-70 y/o, allocated into two groups: the systematic training (ST) group including master athletes with a physical activity level (PAL) >1.6, and the non-systematic training group (NST) composed by subjects with a PAL <1.5. Body composition, diet, biochemical and endocrine markers were analyzed. The ST group showed lower myostatin (MSTN) and irisin (IRI) levels, two strong regulators of SMM. The insulin growth factor-1 (IGF-1) was higher in the ST. This is consistent with most of the evidence in young athletes and resistance training programs, where IGF-1 and IRI seem to play a crucial role in maintaining anabolic status in master athletes.

Pinto Bean Amino Acid Digestibility and Score in a Mexican Dish with Corn Tortilla and Guacamole, Evaluated in Adults Using a Dual-Tracer Isotopic Method

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.

Metabolic syndrome screening using visceral adipose tissue (VAT) from opportunistic MRI locations in a multi-ethnic population

OBJECTIVE

To determine if visceral adipose tissue (VAT) area measured through MRI can be used opportunistically to assess the presence of cardiometabolic risk factors and compare its performance to simpler adiposity measures.

METHODS

A cross-sectional analysis was carried out on a subset of 1683 participants (856 women) from the Adiposity Phenotype Study (mean age=69.2y; range 59.9-77.4). The association of total VAT area (sum of four cross sections, L1-L2, L2-L3, L3-L4, L4-L5) and each location, as well as BMI and body fat % (per SD) with the metabolic syndrome (MetSx) or its components was evaluated through logistic regression analysis.

RESULTS

Total VAT can be accurately predicted using all sites evaluated (R² range=0.82-0.96). In men, VAT did not show a superior association to MetSx compared to BMI in men. However, in women, VAT was consistently superior to BMI and body fat % in its association to MetSx, independent of ethnicity [odds ratio for BMI, body fat %and total VAT area=2.25 (95% CI: 1.93-2.62); 1.66 (95% CI: 1.36-2.03); 6.20 (95% CI: 4.69-8.21) respectively in all women]. Ethnic-specific odds ratios to MetSx in women ranged from 5.38 to 8.63 for total VAT area and 2.12-4.08 for BMI.

CONCLUSION

Total VAT area can be accurately predicted from individual VAT regions in men and women and offers superior association to BMI for MetSx in women but not in men for five ethnicities. Therefore, opportunistic screening for elevated VAT area in women may be warranted across multiple ethnic groups.

The "Super-Child" Approach Is Applied To Estimate Retinol Kinetics and Vitamin A Total Body Stores in Mexican Preschoolers

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 ∼2.4 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.

Association of cagA+ Helicobacter pylori strains with high urease activity and dyspepsia in Mexican adults

INTRODUCTION AND AIMS

Helicobacter pylori (H. pylori) is associated with a higher risk of peptic ulcer and gastric cancer. The sole presence of the bacterium is not a determinant of clinical outcome, but rather the interaction of strain type and host factors determines the risk of disease. Our aim was to study the association between bacterial load, strain type, and gastric symptoms in H. pylori-positive subjects.

MATERIALS AND METHODS

In a community survey, a diagnostic ¹³C-urea breath test for H. pylori was performed on 302 volunteers that were not taking antibiotics, antacids, or proton pump inhibitors one month prior to the test. The breath test produced 25 H. pylori-positive subjects, between 25-74 years of age, who then took a gastric symptoms survey and were tested for the presence of the cagA genotype in gastric juice, using the Entero-test®. Bacterial load was determined as a measure of urease activity, utilizing the delta over baseline value, obtained in the ¹³C-urea breath test.

RESULTS

A total of 48% of the H. pylori-positive subjects were cagA+. A positive association was found between cagA status and high gastric urease activity (P<.0001) and the latter was significantly associated with the presence of symptoms (P<.0001).

CONCLUSION

Gastric urease activity was strongly associated with dyspeptic symptoms and cagA+ H. pylori. Elevated ¹³C-delta over baseline values could be used as indicators of a higher risk for gastric disease.

[Helicobacter pylori infection in the HIV + population: a comorbidity to think about]

Introducción

. Las alteraciones gastrointestinales, son frecuentes en VIH+. Helicobacter pylori puede ser una causa infradiagnosticada.

Material y métodos

Se realizó una búsqueda retrospectiva de pacientes VIH+ con infección por H. pylori entre enero de 1998 hasta diciembre de 2017.

Resultados

Se incluyeron 132 pacientes. La dispepsia fue la sintomatología más frecuente. Un 88,5% tuvo gastritis crónica atrófica. Se consiguió la erradicación en 102 (77,3%). La curación fue más frecuente con pauta cuádruple (p=0,004) y en los más jóvenes (p=0,041).

Conclusión

La infección por H. pylori podría ser responsable de manifestaciones digestivas inespecíficas en los pacientes VIH+.

Effectiveness of the Diabetes Prevention Program for Obesity Treatment in Real World Clinical Practice in a Middle-Income Country in Latin America

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.

Serum Retinol and Anemia in Women of Reproductive Age from Saint-Marc, Haiti (P02-008-19)

Objectives

The objective was to assess serum retinol concentration in women of reproductive age from Haiti by HPLC and a portable photometer, as well as the presence of anemia and hemoglobin (Hb) concentration.

Methods

Cross-sectional comparative study design. Women of reproductive age from the program to improve food security in Haiti (AKOSAA) were eligible to participate. Weight and height were measured and Body Mass Index (BMI) was calculated. A sample of venous blood (5 mL) was collected to assess serum retinol (SR) using HPLC and a portable photometer. Hemoglobin concentration was determined using HemoCue and C-reactive protein (Spinreact E-17176, St Esteve de Bas), was used as a marker of inflammation.

Results

Age range among participants (n = 163) was 15–50 years old. Low weight was identified in15% (n = 24) of enrolled women according to BMI. Vitamin A deficiency (VAD) was identified in 55% (n = 90) of the study population according to serum retinol assessed by HPLC (reference method) versus 26.4% identified using the portable photometer (weighted Kappa = 0.10), which is considered extremely poor. Severe VAD was not found but mild and severe VAD was identified in 38.7% and 16% of women, respectively. When the difference and average of measurements of both methods were compared, bias was 0.20 (IC 95%: 0.14, 0.27). Lin's concordance coefficient (ρc), an analysis of accuracy and precision that assesses how every pair of observations falls over the line of identity (45°), was extremely poor, because it was found below 0.90 (ρc = 0.19). On the other hand, 45% (n = 73) of participants had anemia (Hb < 12 g/dL). No inflammation was observed, since C-reactive protein was below 6 mg/L.

Conclusions

In Haiti VAD as well as anemia were found to be a public health problem. As long as the socioeconomical situation does not substantially improve in this región, supplementation policies and food fortification must be implemented to be able to fight hidden hunger.

Funding Sources

International Atomic Energy Agency (IAEA) CRP contract No. 18,223. Sight and Life donated the iCheckFluoro® equipment and reagents.

Isotopic Tools for Strengthening Health and Nutritional Monitoring and their Current Applications in Developing Regions of the World

Nuclear and isotope methods in one form or another are regarded as essential tools for carrying out nutrition research besides enhancing sensitivity of nutrition monitoring techniques. They have been used extensively in industrialized countries to analyze human energy requirements, body composition including bone mineral density, to determine food composition, and to study metabolism of important nutrients such as protein, fat, vitamins, and minerals. The information acquired has led to many improvements in nutrition and health. Importantly, the developmental needs of countries in economic transition are being increasingly identified and resolved through field applications of isotopic tools, thus strengthening health and nutrition monitoring. Currently, several strategic applications of isotopic techniques are being introduced in developing countries where they can benefit millions through monitoring improvement in nutritional status, and serve as specific indicators of broader social and economic advances. These examples are highlighted in this report.

Body Composition in Mexican Adults by Air Displacement Pletismography (ADP) with the Bod-Pod and Deuterium Oxide Dilution Using Infrared Spectroscopy (IRS-DOD)

Thirty four subjects (13 men and 21 women), 24 to 70 years old from northern Mexico, were measured for body density by air displacement plethysmography (ADP) with the BOD-POD, and for total body water by deuterium oxide dilution and infrared spectroscopy (IRS-DOD). Subjects were given a 30 g dose of deuterium oxide. Saliva samples were filtered, sublimated, and deuterium was measured using a Miran 1 FF, IRS. Linear regression of the fat mass (FM) derived from both methods showed that the intercept (0.071) was not different from zero (p = .96) and the slope was 0.96 (p < .0001) demonstrating the techniques to be equivalent. Further, mean FM was 26.7 ± 12.4 and 25.6 ± 12.4 kg, for IRS-DOD and ADP techniques, respectively (p = .08). Precision analysis by the model R2 showed that 92.3% of the variability was explained (SEM = 3.4 kg). Bland-Altman analysis showed no significant bias (r = 0.017; p = .93). Mean difference between methods was −1.08 (CI: −2.3 to + 0.13) kg FM.

Measurement of Deuterium Oxide by Infrared Spectroscopy and Isotope Ratio Mass Spectrometry for Quantifying Daily Milk Intake in Breastfed Infants and Maternal Body Fat

Measurements of deuterium oxide concentrations (DOC) in saliva by infrared spectroscopy (IRS) and isotope ratio mass spectrometry (IRMS) were compared for the calculation of infants’ milk intake and maternal body fat. Deuterium oxide (30g) was given to the mother. DOC by IRS and IRMS were 340 ± 209 and 345 ± 202 ppm. The mean difference between both methods (4.62 ± 76.3) was not different from zero (p = .57). Bland and Altman analysis showed no significant overall bias (r = 0.10; p = .33), but dispersion within the limits of agreement. The mean milk intake in the infants’ by IRS and IRMS were 624 ± 296 g/day and 634 ± 327 g/day (p = .642) and the mothers’ mean body fat were 31.3 ± 12% and 31.5 ± 13% (p = .755). The results appear to be the same for milk intake and body fat by the two methods and no evidence of bias was found.

Analysis of type 2 diabetes and obesity genetic variants in Mexican Pima Indians: Marked allelic differentiation among Amerindians at HLA

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/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.

Translational study of obesity management using the Diabetes Prevention Program "Group Lifestyle Balance" in primary care clinics and public hospitals from Mexico: study protocol

Introducción: La obesidad es el principal factor de riesgo para el desarrollo de enfermedades crónicas en México. Varios ensayos clínicos controlados han mostrado que los programas intensivos de cambio de estilo de vida son eficaces para el manejo de obesidad. Estos programas incluyen sesiones frecuentes (14 o más los primeros 6 meses), centradas en hacer mejoras en la dieta y actividad física utilizando un protocolo de cambio de comportamiento. Sin embargo, la mayoría de clínicas de primer nivel y los hospitales públicos aplican tratamientos tradicionales para el manejo de obesidad que tienen resultados limitados. El propósito del estudio es evaluar la efectividad del Programa de Prevención de Diabetes “Grupo de Equilibrio de Estilo de Vida” sobre la pérdida de peso en adultos con sobrepeso y obesidad del inicio a 6 meses y del inicio a 12 meses del seguimiento en clínicas de primer nivel y hospitales públicos de Sonora, México.Material y Métodos: Este es un estudio clínico multicéntrico traslacional, no controlado con diseño pre y post-prueba a 6 y 12 meses. Los proveedores de salud de dos clínicas de primer nivel, dos hospitales públicos y una clínica universitaria serán entrenados con el protocolo del Programa de Prevención de Diabetes, para implementarlo en sus pacientes adultos con sobrepeso y obesidad. Se medirá el peso corporal, índice de masa corporal, circunferencia de cintura, presión sistólica y diastólica, así como escalas de depresión, calidad de vida y estrés, al inicio, 6 y 12 meses. Los parámetros bioquímicos se medirán al inicio y a los 12 meses. La variable de desenlace primaria será el cambio de peso a 6 y 12 meses.Discusión: Este estudio proveerá evidencia científica de la efectividad del protocolo del Programa de Prevención de Diabetes como un modelo para el manejo de obesidad en adultos mexicanos en condiciones de la práctica clínica del mundo real.

Effect of the Holiday Season on Weight Gain: A Narrative Review

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.

'Dose-to-Mother' Deuterium Oxide Dilution Technique: An Accurate Strategy to Measure Vitamin A Intake in Breastfed Infants

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.

Antineoplastic treatment effect on bone mineral density in Mexican breast cancer patients

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.

Environmentally Driven Increases in Type 2 Diabetes and Obesity in Pima Indians and Non-Pimas in Mexico Over a 15-Year Period: The Maycoba Project

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.

Study design of the Maycoba Project: obesity and diabetes in Mexican Pimas

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.

Accuracy of body fat percent and adiposity indicators cut off values to detect metabolic risk factors in a sample of Mexican adults

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.