Lara Dugas

Publications (27) View all

• Article: 25-hydroxyvitamin D levels in African American and Nigerian women.

  Ramon A Durazo-Arvizu, John F Aloia, Lara R Dugas, Bamidele O Tayo, David A Shoham, Anne-Marie Bertino, James K Yeh, Richard S Cooper, Amy Luke
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  ABSTRACT: OBJECTIVES: African Americans (AA) have substantially lower levels of circulating 25-hydroxyvitamin D (25(OH)D) than whites. We compared population-based samples of 25(OH)D in women of African descent from Nigeria and metropolitan Chicago. METHODS: One hundred women of Yoruba ethnicity from southwest Nigeria and 94 African American women from metropolitan Chicago were recruited and compared using a standardized survey protocol and the same laboratory assay for 25(OH)D. RESULTS: Mean 25(OH)D levels were 64 nmol/l among the Nigerians and 29 nmol/l among the AA. Only 10% of the values were shared in common between the groups, and 76% of the Nigerians were above the currently defined threshold for adequate circulating 25(OH)D compared to 5% of the AA. Modest associations were seen between 25(OH)D and measures of obesity, although adjustment for these traits did not materially affect the group differences. CONCLUSION: These data support the presumption that skin color is an adaptive trait which has evolved in part to regulate 25(OH)D. It remains undetermined, however, whether lower values observed in AA have negative health consequences. Am. J. Hum. Biol., 2013. © 2013 Wiley Periodicals, Inc.
  American Journal of Human Biology 04/2013; · 2.27 Impact Factor
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  Article: Protocol for the modeling the epidemiologic transition study: a longitudinal observational study of energy balance and change in body weight, diabetes and cardiovascular disease risk.

  Amy Luke, Pascal Bovet, Terrence E Forrester, Estelle V Lambert, Jacob Plange-Rhule, Dale A Schoeller, Lara R Dugas, Ramon A Durazo-Arvizu, David Shoham, Richard S Cooper, Soren Brage, Ulf Ekelund, Nelia P Steyn
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  ABSTRACT: The prevalence of obesity has increased in societies of all socio-cultural backgrounds. To date, guidelines set forward to prevent obesity have universally emphasized optimal levels of physical activity. However there are few empirical data to support the assertion that low levels of energy expenditure in activity is a causal factor in the current obesity epidemic are very limited. The Modeling the Epidemiologic Transition Study (METS) is a cohort study designed to assess the association between physical activity levels and relative weight, weight gain and diabetes and cardiovascular disease risk in five population-based samples at different stages of economic development. Twenty-five hundred young adults, ages 25-45, were enrolled in the study; 500 from sites in Ghana, South Africa, Seychelles, Jamaica and the United States. At baseline, physical activity levels were assessed using accelerometry and a questionnaire in all participants and by doubly labeled water in a subsample of 75 per site. We assessed dietary intake using two separate 24-hour recalls, body composition using bioelectrical impedance analysis, and health history, social and economic indicators by questionnaire. Blood pressure was measured and blood samples collected for measurement of lipids, glucose, insulin and adipokines. Full examination including physical activity using accelerometry, anthropometric data and fasting glucose will take place at 12 and 24 months. The distribution of the main variables and the associations between physical activity, independent of energy intake, glucose metabolism and anthropometric measures will be assessed using cross-section and longitudinal analysis within and between sites. METS will provide insight on the relative contribution of physical activity and diet to excess weight, age-related weight gain and incident glucose impairment in five populations' samples of young adults at different stages of economic development. These data should be useful for the development of empirically-based public health policy aimed at the prevention of obesity and associated chronic diseases.
  BMC Public Health 12/2011; 11:927. · 2.00 Impact Factor
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  Article: Adiposity is not equal in a multi-race/ethnic adolescent population: NHANES 1999-2004.

  Lara R Dugas, Guichan Cao, Amy H Luke, Ramon A Durazo-Arvizu
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  ABSTRACT: BMI is the preferred measure of adiposity in adolescents. Recent evidence suggests that in adults the relationship between BMI and adiposity can vary by age and race/ethnicity. We investigated the relationship between BMI and percent body fat (%BF) in a large multi-ethnic, nationally representative sample of US adolescents (National Health and Nutrition Examination Survey, NHANES, 1999-2004). BMI was calculated; %BF was derived from dual-energy X-ray absorptiometry data and compared to BMI among adolescents from three groups: non-Hispanic white (NHW), non-Hispanic black (NHB), and Mexican-American (MA). Fractional polynomials were used to model a new equation to estimate %BF from a given BMI. MA boys weighed significantly less than either NHW or NHB boys, while only NHB girls weighed significantly more than the other girls. Among the boys there were no differences in mean BMI, whereas %BF differed significantly between all three groups. For the girls, both BMI and %BF differed significantly the groups with MA girls having the highest %BF. The significant correlates for modeling %BF from BMI included gender, age, race/ethnicity, weight, [formula in text]: the final model explained 79% of the variance in %BF. NHB adolescents had significantly lower %BF for BMI and MA had higher than NHW. Our results indicate that BMI may not be an equivalent measure of %BF in a multi-ethnic population of US adolescents.
  Obesity 03/2011; 19(10):2099-101. · 4.28 Impact Factor
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  Article: Energy expenditure in adults living in developing compared with industrialized countries: a meta-analysis of doubly labeled water studies.

  Lara R Dugas, Regina Harders, Sarah Merrill, Kara Ebersole, David A Shoham, Elaine C Rush, Felix K Assah, Terrence Forrester, Ramon A Durazo-Arvizu, Amy Luke
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  ABSTRACT: There is an assumption that people in developing countries have a higher total energy expenditure (TEE) and physical activity level (PAL) than do people in developed nations, but few objective data for this assertion exist. We conducted a meta-analysis of TEE and PAL by using data from countries that have a low or middle human development index (HDI) compared with those with a high HDI to better understand how energy-expenditure variables are associated with development status and population differences in body size. We performed a literature search for studies in which energy expenditure was measured by using doubly labeled water. Mean data on age, weight, body mass index (BMI; in kg/m(2)), TEE, and PAL were extracted, and HDI status was assessed. Pooled estimates of the mean effect by sex were obtained, and the extent to which age, weight, HDI status, and year of publication explained heterogeneity was assessed. A total of 98 studies (14 studies from low- or middle-HDI countries) that represented 183 cohorts and 4972 individuals were included. Mean (±SE) BMI was lower in countries with a low or middle HDI than in those with a high HDI for both men and women (22.7 ± 1.0 compared with 26.0 ± 0.7, respectively, in men and 24.3 ± 0.7 compared with 26.6 ± 0.4, respectively, in women). In meta-regression models, there was an inverse association of age (P < 0.001) and a positive association of weight (P < 0.001) with TEE for both sexes; there was an association of age only in men with PAL (P < 0.001). There was no association of HDI status with either TEE or PAL. TEE adjusted for weight and age or PAL did not differ significantly between developing and industrialized countries, which calls into question the role of energy expenditure in the cause of obesity at the population level.
  American Journal of Clinical Nutrition 02/2011; 93(2):427-41. · 6.67 Impact Factor
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  Article: Assessing physical activity and its relationship to cardiovascular risk factors: NHANES 2003-2006.

  Amy Luke, Lara R Dugas, Ramon A Durazo-Arvizu, Guichan Cao, Richard S Cooper
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  ABSTRACT: Levels of physical activity (PA) in the general population are difficult to characterize. Historically measurement has been based on self-report, which can be subject to bias. PA monitor use has created opportunities to improve surveillance and analytic research on activity and health. The aims of the current study were to investigate the associations between objectively measured PA and cardiovascular disease risk factors and obesity. Data on PA from accelerometers, demographics, blood pressure, plasma glucose and lipids, self-reported hypertension and diabetes were obtained for adults, ages 20-65, in the NHANES surveys, 2003-2006. Outcomes were assessed as levels of moderate and vigorous activity, percentage of participants meeting recommended guidelines, and the correlations between activity and cardiovascular risk factors. Accelerometry data were available on 3,370 adults. Based on standard algorithms, activity levels were extremely low in all age-gender-race/ethnic groups, with an average of only 1 bout of vigorous activity lasting longer than 1 minute/day. Men spent 35 minutes in moderate activity/day, women 21 minutes; >75% of this activity was accumulated in 1-minute bouts. Levels of activity declined sharply after age 50 in all groups. Negative associations were observed between minutes of combined moderate and vigorous activity and systolic blood pressure, blood glucose, diabetes, hypertension, body mass index and obesity, and a positive association was seen with HDL-cholesterol (all P ≤ 0.03), suggesting valid rank ordering of participants by activity level. The magnitude of the gap between self-report and accelerometry activity must be a result of either a vast social acceptability bias in reporting or inaccurate measurement with accelerometry. Therefore, due to the low validity of self reported PA data for epidemiologic research, it is pertinent to encourage the use of valid, objective methods to assess PA.
  BMC Public Health 01/2011; 11:387. · 2.00 Impact Factor