Early neurological development and nutritional status in Mexican socially deprived contexts

Early childhood development (ECD) is a critical stage in the intergenerational process of human development. Targeted interventions depend on accurate and up-to-date ECD measurements. This paper presents estimates for the nutritional and neurodevelopmental status of socially marginalized children in Mexico. We performed a cross-sectional study based on data collected in 2019-2020 during home visits to 1,176 children aged 0-38 months across 24 highly marginalized locations in Oaxaca. We assessed nutritional status according to the World Health Organization 2006 child-growth standards and ECD status using the Child Development Evaluation Test, 2nd Edition. We stratified results by sex. Prevalence of stunting was 5.3 percentage points (p.p.) higher (p = 0.023) in males (25.3%; 95% CI: 20.2%, 31.1%) compared to females (20.0%; 95% CI: 15.0%, 26.1%). Overall prevalence rates stood at 5.7% (95% CI: 4.0%, 8.1%) for underweight, 1.5% (95% CI: 0.9%, 2.7%) for wasting and 3.6% (95% CI: 2.3%, 5.7%) for overweight/obesity, with no significant differences by sex. Prevalence of normal development was 8.3 p.p. lower (p = 0.001) in males (39.3%; 95% CI: 34.5%, 44.4%) compared to females (47.6%; 95% CI: 41.6%, 53.6%). By development area, the highest prevalence of suboptimal outcomes among children with developmental lag or at risk of delay was observed in their gross motor and language skills: 24.1% (95% CI: 20.0%, 28.8%) and 38.6% (95% CI: 34.0%, 43.3%), respectively. The largest difference between the sexes was found in the language area. Our results show that childhood development strategies have been insufficient thus far in the studied population. Programs specifically designed to prevent ECD lags and bridge inequality gaps are urgently needed. Trial registration: ClinicalTrials.gov ID: NCT04210362.

Prevalence of Depression and Generalized Anxiety Disorder Among Mexican Indigenous Adolescents and Young Adults: Challenges for Healthcare

Providing evidence on mental disorders in indigenous adolescents is critical to achieving universal health coverage (UHC). The prevalence of symptoms of depression and generalized anxiety disorder symptoms were estimated for 2082 adolescents aged 14-20 years in Chiapas, Mexico. Mental disorders were assessed using the 9-item Patient-Health Questionnaire and the 7-item Generalized Anxiety Disorder Scale. Among the adolescents evaluated, 35.8% suffered from depression or generalized anxiety disorder. Of those, 6.1% reported a previous diagnosis. 32.1% of adolescents with both mental disorders reported having attempted suicide. Gender, substance use, adverse living experiences and living conditions were correlated to the presence of depression and/or generalized anxiety disorder. It is mandatory for Mexican health authorities to develop effective instruments aiming to screen and diagnose mental health conditions in adolescents, as well as to provide timely treatment in primary health-care units.

A Fortified Food Can Be Replaced by Micronutrient Supplements for Distribution in a Mexican Social Protection Program Based on Results of a Cluster-Randomized Trial and Costing Analysis

BACKGROUND

Despite positive nutrition impacts, the prevalence of malnutrition among beneficiaries of Mexico's conditional cash transfer (CCT) program remains high. Greater nutrition impact may have been constrained by the type of nutritional supplements provided.

OBJECTIVE

The objective of this study was to inform a potential modification to the supplements distributed to pregnant and lactating women and children.

METHODS

Impact was assessed using 2 cluster-randomized trials (pregnant women, children) run simultaneously. Communities (n = 54) were randomly assigned to the fortified foods provided by the program (Nutrivida women, Nutrisano children) or alternatives: tablets (women), syrup (children), or micronutrient powders for women (MNP-W) and children (MNP-C). Each supplement for women/children contained the same micronutrients based on the formulations of Nutrivida and Nutrisano, respectively. Pregnant women (aged >18 y) were recruited before 25 weeks of gestation and followed to 3 mo postpartum. Children aged 6-12 mo were recruited and followed to age 24 mo. Primary outcomes were anemia for women and length growth for children. Statistical analyses appropriate for cluster-randomized designs were used, and structural equation modeling to estimate dose-response effects. Supplement costs per beneficiary (daily dose for 18 mo) were estimated for production and distribution.

RESULTS

There was no significant difference in change of anemia prevalence between supplement groups in women, or in length growth between groups in children. One daily dose of any supplement was associated with 0.8 cm greater length growth. From baseline to age 24 mo, the prevalence of anemia in the Nutrisano, syrup, and MNP-C groups decreased by 36.7, 40.8, and 37.9 percentage points, respectively (within-group, P < 0.05; between groups, P > 0.05). Costs per beneficiary ranged from $12.1 (MNP-C) to $94.8 (Nutrivida).

CONCLUSIONS

The CCT program could distribute alternative supplements at lower cost per beneficiary without compromising potential for impact. Acceptance among beneficiaries should also be considered in choice of alternatives. This trial was registered at www.clinicaltrials.gov as NCT00531674.

Fortification of bakery and corn masa-based foods in Mexico and dietary intake of folic acid and folate in Mexican national survey data

BACKGROUND

In Mexico, wheat and corn flour fortification with folic acid (FA) was implemented in 2001 and mandated in 2008, but without direct enforcement. Current Mexican nutrient-content tables do not account for FA contained in bakery bread and corn masa-based foods, which are dietary staples in Mexico.

OBJECTIVE

The objective of this study was to examine the impact of FA fortification of dietary staples on the proportion of the population consuming below the Estimated Average Requirement (EAR) for folate or above the Tolerable Upper Intake Level (UL) for FA.

METHODS

We measured FA and folate content in dietary staples (bakery bread and tortillas) using microbial assays and MS, and we recalculated FA intake from 24-h recall dietary intake data collected in the 2012 Mexican National Health and Nutrition Survey (Encuesta Nacional de Salud y Nutrición) utilizing estimates from our food measurements, using nutrient concentrations from tortillas to approximate nutrient content of other corn masa-derived foods. The revised FA intake estimates were used to examine population-level intake of FA and dietary folate equivalent (DFE) accounting for geographic differences in FA content with statistical models.

RESULTS

FA content in dietary staples was variable, whereas use of FA-fortified flour in corn masa tortillas increased with population size in place of residence. Accounting for dietary staples' FA fortification increased population estimates for FA and DFE intake, resulting in a lower proportion with intake below the EAR and a higher proportion with intake above the UL. Despite accounting for FA-fortified staple foods, 9-33% of women of childbearing age still have intake below the EAR, whereas up to 12% of younger children have intake above the UL.

CONCLUSIONS

Unregulated FA fortification of dietary staples leads to unpredictable total folate intake without adequately impacting the intended target. Our findings suggest that monitoring, evaluation, and enforcement of mandatory fortification policies are needed. Without these, alternate strategies may be needed in order to reach women of childbearing age while avoiding overexposing children.

[Occupational health and safety: educational intervention for cleaning workers in research sectors]

OBJECTIVE

To evaluate the results of educational interven- tion on health and safety regarding principles of biosafety in cleaning workers of a health institution.

MATERIALS AND METHODS

Using concurrent mixed methods, we evaluated a total of 31 workers on their knowledge, attitudes, and practices of biosafety and risk perception. We conducted baseline measurements and two follow-ups. Fractional logistic regression models were fitted with study stage as covariate. Additional models included interactions of study stage with key workers characteristics. Thematic qualitative analysis and triangulation was developed.

RESULTS

The knowledge (+33.3 points, scale 0-100), attitudes (+10.6), and practices (+23.5) increased significantly in the first follow-up; knowledge de- creased in the second follow-up (p<0.001). The qualitative findings revealed an improvement in risk prevention attitudes and practices, framed by experiences of vulnerability, stigma, and discrimination.

CONCLUSIONS

The study provides key elements for biosafety research related to vulnerable groups and it is effective in promoting the health of a disadvantaged and invisible sector.

Physical activity and calorie intake mediate the relationship from depression to body fat mass among female Mexican health workers

Background

Depression is a foremost cause of morbidity throughout the world and the prevalence of depression in women is about twice as high as men. Additionally, overweight and obesity are major global health concerns. We explored the relationship between depression and body fat, and the role of physical activity and diet as mediators of this relationship in a sample of 456 adult female Mexican health workers.

Method

Longitudinal and cross-sectional analyses using data from adult women of the Health Workers Cohort Study (HWCS) Measures of body fat mass (kg from DEXA), dietary intake (kcal from FFQ), leisure time activity (METs/wk) and depression (CES-D) were determined in two waves (2004–2006 and 2010–2011). We explored the interrelation between body fat, diet, leisure time, physical activity, and depression using a cross-lagged effects model fitted to longitudinal data. We also fitted a structural equations model to cross-sectional data with body fat as the main outcome, and dietary intake and physical activity from leisure time as mediators between depression and body fat.

Results

Baseline depression was significantly related to higher depression, higher calorie intake, and lower leisure time physical activity at follow-up. From our cross-sectional model, each standard deviation increase in the depression score was associated with an average increase of 751 ± 259 g (± standard error) in body fat through the mediating effects of calorie intake and physical activity.

Conclusions

The results of this study show how depression may influence energy imbalance between calories consumed and calories expended, resulting in higher body fat among those with a greater depression score. Evaluating the role of mental conditions like depression in dietary and physical activity behaviors should be positioned as a key research goal for better designed and targeted public health interventions.

Trial registration

The HealthWorkers Cohort Study (HWCS) has been approved by the Institutional IRB. Number: 2005–785-012.

Electronic supplementary material

The online version of this article (10.1186/s12966-017-0612-x) contains supplementary material, which is available to authorized users.

A Diabetic Retinopathy Screening Tool for Low-Income Adults in Mexico

INTRODUCTION

A national diabetic retinopathy screening program does not exist in Mexico as of 2017. Our objective was to develop a screening tool based on a predictive model for early detection of diabetic retinopathy in a low-income population.

METHODS

We analyzed biochemical, clinical, anthropometric, and sociodemographic information from 1,000 adults with diabetes in low-income communities in Mexico (from 11,468 adults recruited in 2014-2016). A comprehensive ophthalmologic evaluation was performed. We developed the screening tool through the following stages: 1) development of a theoretical predictive model, 2) performance assessment and validation of the model using cross-validation and the area under the receiver operating characteristic curve (AUC ROC), and 3) optimization of cut points for the classification of diabetic retinopathy. We identified points along the AUC ROC that minimized the misclassification cost function and considered various scenarios of misclassification costs and diabetic retinopathy prevalence.

RESULTS

Time since diabetes diagnosis, high blood glucose levels, systolic hypertension, and physical inactivity were considered risk factors in our screening tool. The mean AUC ROC of our model was 0.780 (validation data set). The optimized cut point that best represented our study population (z = -0.640) had a sensitivity of 82.9% and a specificity of 61.9%.

CONCLUSION

We developed a low-cost and easy-to-apply screening tool to detect people at high risk of diabetic retinopathy in Mexico. Although classification performance of our tool was acceptable (AUC ROC > 0.75), error rates (precision) depend on false-negative and false-positive rates. Therefore, confirmatory assessment of all cases is mandatory.

Dissonant health transition in the states of Mexico, 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013

BACKGROUND

Child and maternal health outcomes have notably improved in Mexico since 1990, whereas rising adult mortality rates defy traditional epidemiological transition models in which decreased death rates occur across all ages. These trends suggest Mexico is experiencing a more complex, dissonant health transition than historically observed. Enduring inequalities between states further emphasise the need for more detailed health assessments over time. The Global Burden of Diseases, Injuries, and Risk Factors Study 2013 (GBD 2013) provides the comprehensive, comparable framework through which such national and subnational analyses can occur. This study offers a state-level quantification of disease burden and risk factor attribution in Mexico for the first time.

METHODS

We extracted data from GBD 2013 to assess mortality, causes of death, years of life lost (YLLs), years lived with disability (YLDs), disability-adjusted life-years (DALYs), and healthy life expectancy (HALE) in Mexico and its 32 states, along with eight comparator countries in the Americas. States were grouped by Marginalisation Index scores to compare subnational burden along a socioeconomic dimension. We split extracted data by state and applied GBD methods to generate estimates of burden, and attributable burden due to behavioural, metabolic, and environmental or occupational risks. We present results for 306 causes, 2337 sequelae, and 79 risk factors.

FINDINGS

From 1990 to 2013, life expectancy from birth in Mexico increased by 3·4 years (95% uncertainty interval 3·1-3·8), from 72·1 years (71·8-72·3) to 75·5 years (75·3-75·7), and these gains were more pronounced in states with high marginalisation. Nationally, age-standardised death rates fell 13·3% (11·9-14·6%) since 1990, but state-level reductions for all-cause mortality varied and gaps between life expectancy and years lived in full health, as measured by HALE, widened in several states. Progress in women's life expectancy exceeded that of men, in whom negligible improvements were observed since 2000. For many states, this trend corresponded with rising YLL rates from interpersonal violence and chronic kidney disease. Nationally, age-standardised YLL rates for diarrhoeal diseases and protein-energy malnutrition markedly decreased, ranking Mexico well above comparator countries. However, amid Mexico's progress against communicable diseases, chronic kidney disease burden rapidly climbed, with age-standardised YLL and DALY rates increasing more than 130% by 2013. For women, DALY rates from breast cancer also increased since 1990, rising 12·1% (4·6-23·1%). In 2013, the leading five causes of DALYs were diabetes, ischaemic heart disease, chronic kidney disease, low back and neck pain, and depressive disorders; the latter three were not among the leading five causes in 1990, further underscoring Mexico's rapid epidemiological transition. Leading risk factors for disease burden in 1990, such as undernutrition, were replaced by high fasting plasma glucose and high body-mass index by 2013. Attributable burden due to dietary risks also increased, accounting for more than 10% of DALYs in 2013.

INTERPRETATION

Mexico achieved sizeable reductions in burden due to several causes, such as diarrhoeal diseases, and risks factors, such as undernutrition and poor sanitation, which were mainly associated with maternal and child health interventions. Yet rising adult mortality rates from chronic kidney disease, diabetes, cirrhosis, and, since 2000, interpersonal violence drove deteriorating health outcomes, particularly in men. Although state inequalities from communicable diseases narrowed over time, non-communicable diseases and injury burdens varied markedly at local levels. The dissonance with which Mexico and its 32 states are experiencing epidemiological transitions might strain health-system responsiveness and performance, which stresses the importance of timely, evidence-informed health policies and programmes linked to the health needs of each state.

FUNDING

Bill & Melinda Gates Foundation, Instituto Nacional de Salud Pública.

Prenatal supplementation with DHA improves attention at 5 y of age: a randomized controlled trial

BACKGROUND

Docosahexanoic acid (DHA) is an important constituent of the brain. Evidence from well-designed intervention trials of the long-term benefits of increasing DHA intake during pregnancy has been sparse.

OBJECTIVE

We evaluated global cognition, behavior, and attention at age 5 y in the offspring of Mexican women who participated in a randomized controlled trial of prenatal DHA supplementation.

DESIGN

A total of 1094 women were randomly assigned to receive 400 mg of either DHA or placebo/d from 18 to 22 wk of pregnancy until delivery. We assessed cognitive development and behavioral and executive functioning, including attention, in 797 offspring at age 5 y (82% of 973 live births) with the use of the McCarthy Scales of Children's Abilities (MSCA), the parental scale of the Behavioral Assessment System for Children, Second Edition (BASC-2), and the Conners' Kiddie Continuous Performance Test (K-CPT). We compared the groups on raw scores, T-scores, and standardized scores, as appropriate. We examined heterogeneity by the quality of the home environment, maternal intelligence, and socioeconomic status.

RESULTS

There were no group differences for MSCA scores (P > 0.05), but the positive effect of the home environment at 12 mo on general cognitive abilities was attenuated in the DHA group compared with in the placebo group (P-interaction < 0.05). There were no differences between groups on the BASC-2. On the K-CPT, offspring in the DHA group showed improved mean ± SD T-scores compared with those of the placebo group for omissions (DHA: 47.6 ± 10.3; placebo: 49.6 ± 11.2; P < 0.01) with no differences (P > 0.05) for the other K-CPT scores or of the proportion who were clinically at risk of attention deficit hyperactivity disorders after Bonferroni correction for multiple comparisons.

CONCLUSION

Prenatal exposure to DHA may contribute to improved sustained attention in preschool children. This trial was registered at clinicaltrials.gov as NCT00646360.

Bias correction of nutritional status estimates when reported age is used for calculating WHO indicators in children under five years of age

OBJECTIVE

To assess the performance of a simple correction method for nutritional status estimates in children under five years of age when exact age is not available from the data.

MATERIALS AND METHODS

The proposed method was based on the assumption of symmetry of age distributions within a given month of age and validated in a large population-based survey sample of Mexican preschool children.

RESULTS

The main distributional assumption was consistent with the data. All prevalence estimates derived from the correction method showed no statistically significant bias. In contrast, failing to correct attained age resulted in an underestimation of stunting in general and an overestimation of overweight or obesity among the youngest.

CONCLUSIONS

The proposed method performed remarkably well in terms of bias correction of estimates and could be easily applied in situations in which either birth or interview dates are not available from the data.

Time trends and sex differences in associations between socioeconomic status indicators and overweight-obesity in Mexico (2006-2012)

Background

Although the associations between specific socioeconomic status (SES) indicators and overweight or obesity (OWOB) have been studied in different countries, fewer evidence exists for these associations when multiple SES indicators are considered simultaneously. Furthermore, there are few studies investigating time trends in OWOB and their relation with SES in upper-middle income countries, especially for men. The present study contributes to a better understanding of the nature and evolution of the associations between SES indicators and OWOB in the Mexican adult population.

Methods

We pooled data from the 2006 and 2012 National Health and Nutrition Surveys in Mexico and obtained covariate-adjusted prevalence from a design-based logistic multiple regression model. Covariates included a wealth index, education, occupational status, marital status, and all interactions for each covariate with sex (male/female) and survey year.

Results

For men, the association between wealth and OWOB remained positive in general but curvature was more evident in 2012. The wealth-OWOB association in women showed an inverted-U pattern at both years with a positive slope that turned into a negative one as wealth increased. Among women, OWOB prevalence at the college/university education level was approximately 12.0 ± 2.4 (percentage points ± standard error) lower compared with the elementary education level. We did not find differences between educational categories for men in 2006, but in 2012 OWOB tended to be higher among the more educated. The prevalence of obesity in women increased at wealth levels from the middle and upper-middle section of the wealth distributions. Overall OWOB prevalence was near 70 % in 2012 for both sexes.

Conclusions

Among Mexican women, the associations between SES indicators and excess body weight were consistent to those found in developed countries. Among Mexican men, higher education was not associated with a lower prevalence of OWOB but the positive association between wealth and OWOB weakened as wealth increased. The overall prevalence of OWOB was very high for both sexes; its reduction should remain a public health priority given the consequences of nutrition-related chronic diseases, disability and health care costs.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-2608-2) contains supplementary material, which is available to authorized users.

Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks in 188 countries, 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013

BACKGROUND

The Global Burden of Disease, Injuries, and Risk Factor study 2013 (GBD 2013) is the first of a series of annual updates of the GBD. Risk factor quantification, particularly of modifiable risk factors, can help to identify emerging threats to population health and opportunities for prevention. The GBD 2013 provides a timely opportunity to update the comparative risk assessment with new data for exposure, relative risks, and evidence on the appropriate counterfactual risk distribution.

METHODS

Attributable deaths, years of life lost, years lived with disability, and disability-adjusted life-years (DALYs) have been estimated for 79 risks or clusters of risks using the GBD 2010 methods. Risk-outcome pairs meeting explicit evidence criteria were assessed for 188 countries for the period 1990-2013 by age and sex using three inputs: risk exposure, relative risks, and the theoretical minimum risk exposure level (TMREL). Risks are organised into a hierarchy with blocks of behavioural, environmental and occupational, and metabolic risks at the first level of the hierarchy. The next level in the hierarchy includes nine clusters of related risks and two individual risks, with more detail provided at levels 3 and 4 of the hierarchy. Compared with GBD 2010, six new risk factors have been added: handwashing practices, occupational exposure to trichloroethylene, childhood wasting, childhood stunting, unsafe sex, and low glomerular filtration rate. For most risks, data for exposure were synthesised with a Bayesian meta-regression method, DisMod-MR 2.0, or spatial-temporal Gaussian process regression. Relative risks were based on meta-regressions of published cohort and intervention studies. Attributable burden for clusters of risks and all risks combined took into account evidence on the mediation of some risks such as high body-mass index (BMI) through other risks such as high systolic blood pressure and high cholesterol.

FINDINGS

All risks combined account for 57·2% (95% uncertainty interval [UI] 55·8-58·5) of deaths and 41·6% (40·1-43·0) of DALYs. Risks quantified account for 87·9% (86·5-89·3) of cardiovascular disease DALYs, ranging to a low of 0% for neonatal disorders and neglected tropical diseases and malaria. In terms of global DALYs in 2013, six risks or clusters of risks each caused more than 5% of DALYs: dietary risks accounting for 11·3 million deaths and 241·4 million DALYs, high systolic blood pressure for 10·4 million deaths and 208·1 million DALYs, child and maternal malnutrition for 1·7 million deaths and 176·9 million DALYs, tobacco smoke for 6·1 million deaths and 143·5 million DALYs, air pollution for 5·5 million deaths and 141·5 million DALYs, and high BMI for 4·4 million deaths and 134·0 million DALYs. Risk factor patterns vary across regions and countries and with time. In sub-Saharan Africa, the leading risk factors are child and maternal malnutrition, unsafe sex, and unsafe water, sanitation, and handwashing. In women, in nearly all countries in the Americas, north Africa, and the Middle East, and in many other high-income countries, high BMI is the leading risk factor, with high systolic blood pressure as the leading risk in most of Central and Eastern Europe and south and east Asia. For men, high systolic blood pressure or tobacco use are the leading risks in nearly all high-income countries, in north Africa and the Middle East, Europe, and Asia. For men and women, unsafe sex is the leading risk in a corridor from Kenya to South Africa.

INTERPRETATION

Behavioural, environmental and occupational, and metabolic risks can explain half of global mortality and more than one-third of global DALYs providing many opportunities for prevention. Of the larger risks, the attributable burden of high BMI has increased in the past 23 years. In view of the prominence of behavioural risk factors, behavioural and social science research on interventions for these risks should be strengthened. Many prevention and primary care policy options are available now to act on key risks.

FUNDING

Bill & Melinda Gates Foundation.

The effect of vitamin D supplementation on serum lipids in postmenopausal women with diabetes: A randomized controlled trial

BACKGROUND & AIMS

Dyslipidemia is a risk factor for cardiovascular disease that has become an increasing public health problem. Dyslipidemia is especially relevant in vulnerable populations such as postmenopausal women. Low serum levels of 25-hydroxyvitamin D have been associated with an unfavourable lipid profile. Due to contradictory findings from intervention trials, we investigated the effect of vitamin D supplementation on serum lipids in postmenopausal women with type 2 diabetes.

METHODS

A total of 104 postmenopausal women with type 2 diabetes were randomly assigned in a double-blind manner to 1 of 2 groups taking a daily tablet for 6 months: a group consuming 4000 IU tablets of a vitamin D supplement (vitamin D group n = 52) or a group consuming placebo tablets (placebo group n = 52).

RESULTS

The study was completed by 99 participants. However, as the analysis was based on an intention-to-treat approach, all 104 women were included in the final analysis. In the vitamin D group mean serum levels of 25(OH)D3 improved significantly at the end of the follow-up period (+25.5 nmol/L; P = <0.001). Our findings revealed no significant changes in low density lipoproteins, high density lipoproteins and total cholesterol concentrations, but did identify a greater decrease in serum triglycerides in the vitamin D group. The average effect of supplementation on the treated group was -34.24 mg/dL (P = 0.021), while the average treatment effect was -31.8 mg/dL (P = 0.023).

CONCLUSIONS

Our results suggest that supplementation with vitamin D (4000 IU/d) may have a beneficial effect on serum triglyceride levels without otherwise affecting levels of other lipids.

TRIAL REGISTRATION

clinicaltrial.gov; identifier NCT01019642.

Global, regional, and national incidence and mortality for HIV, tuberculosis, and malaria during 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013

BACKGROUND

The Millennium Declaration in 2000 brought special global attention to HIV, tuberculosis, and malaria through the formulation of Millennium Development Goal (MDG) 6. The Global Burden of Disease 2013 study provides a consistent and comprehensive approach to disease estimation for between 1990 and 2013, and an opportunity to assess whether accelerated progress has occured since the Millennium Declaration.

METHODS

To estimate incidence and mortality for HIV, we used the UNAIDS Spectrum model appropriately modified based on a systematic review of available studies of mortality with and without antiretroviral therapy (ART). For concentrated epidemics, we calibrated Spectrum models to fit vital registration data corrected for misclassification of HIV deaths. In generalised epidemics, we minimised a loss function to select epidemic curves most consistent with prevalence data and demographic data for all-cause mortality. We analysed counterfactual scenarios for HIV to assess years of life saved through prevention of mother-to-child transmission (PMTCT) and ART. For tuberculosis, we analysed vital registration and verbal autopsy data to estimate mortality using cause of death ensemble modelling. We analysed data for corrected case-notifications, expert opinions on the case-detection rate, prevalence surveys, and estimated cause-specific mortality using Bayesian meta-regression to generate consistent trends in all parameters. We analysed malaria mortality and incidence using an updated cause of death database, a systematic analysis of verbal autopsy validation studies for malaria, and recent studies (2010-13) of incidence, drug resistance, and coverage of insecticide-treated bednets.

FINDINGS

Globally in 2013, there were 1·8 million new HIV infections (95% uncertainty interval 1·7 million to 2·1 million), 29·2 million prevalent HIV cases (28·1 to 31·7), and 1·3 million HIV deaths (1·3 to 1·5). At the peak of the epidemic in 2005, HIV caused 1·7 million deaths (1·6 million to 1·9 million). Concentrated epidemics in Latin America and eastern Europe are substantially smaller than previously estimated. Through interventions including PMTCT and ART, 19·1 million life-years (16·6 million to 21·5 million) have been saved, 70·3% (65·4 to 76·1) in developing countries. From 2000 to 2011, the ratio of development assistance for health for HIV to years of life saved through intervention was US$4498 in developing countries. Including in HIV-positive individuals, all-form tuberculosis incidence was 7·5 million (7·4 million to 7·7 million), prevalence was 11·9 million (11·6 million to 12·2 million), and number of deaths was 1·4 million (1·3 million to 1·5 million) in 2013. In the same year and in only individuals who were HIV-negative, all-form tuberculosis incidence was 7·1 million (6·9 million to 7·3 million), prevalence was 11·2 million (10·8 million to 11·6 million), and number of deaths was 1·3 million (1·2 million to 1·4 million). Annualised rates of change (ARC) for incidence, prevalence, and death became negative after 2000. Tuberculosis in HIV-negative individuals disproportionately occurs in men and boys (versus women and girls); 64·0% of cases (63·6 to 64·3) and 64·7% of deaths (60·8 to 70·3). Globally, malaria cases and deaths grew rapidly from 1990 reaching a peak of 232 million cases (143 million to 387 million) in 2003 and 1·2 million deaths (1·1 million to 1·4 million) in 2004. Since 2004, child deaths from malaria in sub-Saharan Africa have decreased by 31·5% (15·7 to 44·1). Outside of Africa, malaria mortality has been steadily decreasing since 1990.

INTERPRETATION

Our estimates of the number of people living with HIV are 18·7% smaller than UNAIDS's estimates in 2012. The number of people living with malaria is larger than estimated by WHO. The number of people living with HIV, tuberculosis, or malaria have all decreased since 2000. At the global level, upward trends for malaria and HIV deaths have been reversed and declines in tuberculosis deaths have accelerated. 101 countries (74 of which are developing) still have increasing HIV incidence. Substantial progress since the Millennium Declaration is an encouraging sign of the effect of global action.

FUNDING

Bill & Melinda Gates Foundation.

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.