RESUMO
BACKGROUND: Childhood overweight and obesity (OW/OB) is increasingly centered in low- and middle-income countries (LMICs) as rural populations experience market integration and lifeway change. Most explanatory studies have relied on imprecise estimates of children's energy expenditure, restricting understanding of the relative effects of changes in diet and energy expenditure on the development of OW/OB in transitioning contexts. OBJECTIVES: This study used gold-standard measurements of children's energy expenditure to investigate the changes that underlie OW/OB and the nutrition/epidemiologic transition. METHODS: Cross-sectional data were collected from "rural" (n = 43) Shuar forager-horticulturalist children and their "peri-urban" (n = 34) Shuar counterparts (age 4-12 y) in Amazonian Ecuador. Doubly labeled water measurements of total energy expenditure (TEE; kcal/d), respirometry measurements of resting energy expenditure (REE; kcal/d), and measures of diet, physical activity, immune activity, and market integration were analyzed primarily using regression models. RESULTS: Peri-urban children had higher body fat percentage (+8.1%, P < 0.001), greater consumption of market-acquired foods (multiple P < 0.001), lower concentrations of immune activity biomarkers (multiple P < 0.05), and lower REE (-108 kcal/d, P = 0.002) than rural children. Despite these differences, peri-urban children's TEE was indistinguishable from that of rural children (P = 0.499). Moreover, although sample-wide IgG concentrations and household incomes predicted REE (both P < 0.05), no examined household, immune activity, or physical activity measures were related to children's overall TEE (all P > 0.09). Diet and energy expenditure associations with adiposity demonstrate that only reported consumption of market-acquired "protein" and "carbohydrate" foods predicted children's body fat levels (multiple P < 0.05). CONCLUSIONS: Despite underlying patterns in REE, Shuar children's TEE is not reliably related to market integration and-unlike dietary measures-does not predict adiposity. These findings suggest a leading role of changing dietary intake in transitions to OW/OB in LMICs.
Assuntos
Comércio , Metabolismo Energético , Alimentos/economia , Sobrepeso , População Rural , População Urbana , Adiposidade , Criança , Pré-Escolar , Estudos Transversais , Equador , Comportamento Alimentar , Feminino , Abastecimento de Alimentos , Humanos , Povos Indígenas , MasculinoRESUMO
BACKGROUND AND PURPOSE: The results of the A Randomized Trial of Unruptured Brain Arteriovenous (ARUBA) study, indicating that conservative medical management of unruptured brain arteriovenous malformations (UBAVM) is superior to interventional therapy, have generated debates that have hampered their application into clinical practice. Irrespectively of study conclusions, it seems reasonable to explore how much better interventional therapy would have to be to become competitive with conservative medical management. METHODS: We conducted an exploratory analysis to replicate the original data from ARUBA. The functional form of the replicated ARUBA data, according to their Weibull distribution, allowed estimation of parameters. We carried out Monte Carlo simulations while introducing theoretical reductions of interventional risk, and the results were used to construct theoretical and example Kaplan-Meier curves from simulations. RESULTS: The "ARUBA Replication" analysis showed results nearly identical to those published in the study, with an estimated hazard ratio of 0.27 (95% CI: 0.14-0.55). At 50% interventional risk reduction, the simulations showed an estimated event rate of 14.9%, and the protective effect of conservative medical management was no longer statistically significant. Greater risk reductions hastened the time to benefit for interventional therapy, and an 80% risk reduction demonstrated superiority of interventional therapy at just over 2 years Hazard Ratio (HR: 1.44, 95% CI: 0.55-4.92). CONCLUSIONS: Reduction in risk of interventional therapy by 50%-80% results in more competitive clinical outcomes, equating or surpassing the benefit of conservative medical management of UBAVM. This conjecture should be taken into consideration in the design of future studies of this patient population, particularly because it is supported by recent observational studies.