RESUMEN
BACKGROUND: Experimental evidence suggests that p,p'-DDE might be involved in the development of diabetes and hypertension (HTN); however, the evidence in humans is inconclusive. OBJECTIVE: To summarize the epidemiological evidence for the association of p,p'-DDT exposure and its breakdown products with the risk of diabetes and HTN from prospective studies. METHODS: We performed a systematic review and meta-analysis based on the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. Eligible studies (prospective) were search in PubMed, Web of Science, EBSCO, and SciELO databases (July 11, 2020). Different search algorithms were used for diabetes and HTN. Pooled odds ratios (ORs) were estimated from meta-analysis with random effects for each exposure and outcome. RESULTS: A total of 23 prospective studies were included in this review, 16 assessed diabetes and seven HTN; very few measured p,p'-DDT. Exposure to p,p'-DDE was associated with a slightly increased risk of type 2 diabetes (T2D) (pooled OR = 1.44; 95%CI: 1.00, 2.07; p = 0.049) and HTN (pooled OR = 1.21; 95%CI: 1.07, 1.38). Dose-response meta-analysis suggested a non-linear relation between p,p'-DDE and T2D. Exposure to p,p'-DDE was not associated with gestational diabetes (pooled OR = 1.01; 95%CI: 0.94, 1.09); similarly, p,p'-DDT was not associated with T2D (pooled OR = 1.03; 95%CI: 0.79, 1.35). CONCLUSIONS: Evidence from prospective studies suggests that exposure to p,p'-DDE, the main breakdown product of p,p'-DDT, might increase the risk of developing T2D; such increase may be apparent only at low levels. Exposure to p,p'-DDE may also increase the risk of having HTN; however, further evidence is required.
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Diabetes Mellitus Tipo 2 , Hipertensión , Plaguicidas , DDT , Diabetes Mellitus Tipo 2/epidemiología , Diclorodifenil Dicloroetileno , Humanos , Hipertensión/epidemiología , Estudios ProspectivosRESUMEN
OBJECTIVE: To assess the effect of intimate partner violence on the risk of depression and depressive symptoms among adult women. METHOD: We analyzed data from the Mexican Health Workers' Cohort study (n=470). Type and severity of intimate partner violence was ascertained between 2004 and 2011. Self-reported medical diagnosis of depression (2011) was the main outcome; depressive symptoms ascertained with the Centre for Epidemiologic Studies-Depression (CES-D) scale was the secondary outcome. Random-effects regressions were run to model the risk of depression (logistic) and depressive symptoms (linear) in relation to intimate partner violence. RESULTS: 41.9% women experienced intimate partner violence at baseline. The incidence of depression was 7.2%. The risk of depression increased with any type of IPV (adjusted odds ratio [aOR]=2.9; 95% confidence interval [95%CI]: 1.4-6.2) and with physical (aOR=4.3; 95%CI: 1.8-10.1), psychological (aOR=3.1; 95%CI: 1.4-6.6) and sexual (aOR=3.1; 95%CI: 1.2-8.2) violence. Depressive symptoms (CES-D) increased slightly with physical and sexual intimate partner violence. CONCLUSIONS: Intimate partner violence was associated with a higher risk of depression in this sample of women working in a Mexican health facility. Our results indicate the need to develop infrastructure, to implement strategies of attention and counselling, and to provide a safe environment in the workplace for women who experience intimate partner violence.
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Depresión , Violencia de Pareja , Adulto , Estudios de Cohortes , Estudios Transversales , Depresión/epidemiología , Femenino , Instituciones de Salud , Humanos , Masculino , México/epidemiología , Prevalencia , Factores de RiesgoRESUMEN
OBJECTIVE: Our aim was to examine prospectively predictors of subclinical renal alterations among adults without chronic kidney disease. MATERIALS AND METHODS: We analyzed data from a cohort of Mexican adults (n=757). Kidney function (2010) was assessed with the estimated glomerular filtration rate (eGFR-Cr), serum creatinine and uric acid. Predictors of each kidney function marker (2004) were identified with linear and logistic regression models. RESULTS: 33% had an eGFR-Cr 40 years old and users of antihypertensive medication; and higher among those with a high protein intake. Serum creatinine predictors were similar to those observed for eGFR-Cr. Uric acid decreased in men, among those with obesity, hypertension and high cholesterol. CONCLUSIONS: Conventional kidney function biomarkers are useful to identify subclinical alterations. Some predictors of kidney function are potentially modifiable, therefore susceptible for intervention among high-risk groups.
OBJETIVO: Examinar prospectivamente los predictores de alteraciones subclínicas de la función renal en adultos sin diagnóstico previo de enfermedad renal crónica. MATERIAL Y MÉTODOS: Se analizaron datos de una cohorte de adultos mexicanos (n=757). La función renal (2010) se midió mediante la tasa de filtración glomerular estimada (TFGECr), creatinina y ácido úrico séricos. Los predictores (2004) se identificaron con modelos de regresión lineal y logística. RESULTADOS: Se clasificó 33% con TFGE-Cr disminuida.La TFGE-Cr fue menor en hombres, en >40 años y en usuarios de antihipertensivos; y fue mayor en aquellos con consumo proteico alto. Los predictores de la creatinina fueron similares a los de la TFGE-Cr. El ácido úrico disminuyó en participantes hombres, con obesidad, hipertensión e hipercolesterolemia. CONCLUSIONES: Los biomarcadores séricos convencionales son útiles para identificar alteraciones subclínicas de la función renal. Algunos predictores de la función renal son potencialmente modificables, por tanto susceptibles de intervención.
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Riñón/fisiología , Adulto , Estudios de Cohortes , Tasa de Filtración Glomerular , Humanos , Masculino , México , Ácido Úrico/orinaRESUMEN
Resumen: Objetivo: Examinar prospectivamente los predictores de alteraciones subclínicas de la función renal en adultos sin diagnóstico previo de enfermedad renal crónica. Material y métodos: Se analizaron datos de una cohorte de adultos mexicanos (n=757). La función renal (2010) se midió mediante la tasa de filtración glomerular estimada (TFGE-Cr), creatinina y ácido úrico séricos. Los predictores (2004) se identificaron con modelos de regresión lineal y logística. Resultados: Se clasificó 33% con TFGE-Cr disminuida. La TFGE-Cr fue menor en hombres, en >40 años y en usuarios de antihipertensivos; y fue mayor en aquellos con consumo proteico alto. Los predictores de la creatinina fueron similares a los de la TFGE-Cr. El ácido úrico disminuyó en participantes hombres, con obesidad, hipertensión e hipercolesterolemia. Conclusión. Los biomarcadores séricos convencionales son útiles para identificar alteraciones subclínicas de la función renal. Algunos predictores de la función renal son potencialmente modificables, por tanto susceptibles de intervención.
Abstract: Objectives: Our aim was to examine prospectively predictors of subclinical renal alterations among adults without chronic kidney disease. Materials and methods: We analyzed data from a cohort of Mexican adults (n=757). Kidney function (2010) was assessed with the estimated glomerular filtration rate (eGFR-Cr), serum creatinine and uric acid. Predictors of each kidney function marker (2004) were identified with linear and logistic regression models. Results: 33% had an eGFR-Cr <90 ml/min/1.73 m2. eGFR-Cr was lower among men, those >40 years old and users of antihypertensive medication; and higher among those with a high protein intake. Serum creatinine predictors were similar to those observed for eGFR-Cr. Uric acid decreased in men, among those with obesity, hypertension and high cholesterol. Conclusion: Conventional kidney function biomarkers are useful to identify subclinical alterations. Some predictors of kidney function are potentially modifiable, therefore susceptible for intervention among high-risk groups.
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Adulto , Humanos , Masculino , Riñón/fisiología , Ácido Úrico/orina , Estudios de Cohortes , Tasa de Filtración Glomerular , MéxicoRESUMEN
BACKGROUND: A higher incidence rate (IR) of acute gastrointestinal (GI) infections associated with prenatal exposure to p,p'-DDE was suggested by the results in two studies. Given the high mortality rate due to childhood diarrhea in some countries with ongoing use of DDT, additional data on this association is relevant for those making decisions about vector-borne disease control. OBJECTIVE: To evaluate whether higher levels of prenatal exposure to p,p'-DDE and p,p'-DDT increase the risk of having diarrhea in a birth cohort of boys from tropical Mexico. METHODS: Our analysis was based on 747 boys whose exposure was measured in maternal serum collected at delivery (2002-2003). Mothers reported the number of diarrhea episodes of their children during in-person interviews. The median age of the children at their last interview was 21.4 months. Poisson regression models were fitted to estimate adjusted incidence rate ratios (aIRR) of diarrhea by levels of p,p'-DDE and p,p'-DDT. RESULTS: Overall, there were 1.7 episodes of diarrhea per child-year. Among those in the highest category of exposure (> 9µg DDE/g serum lipid), the aIRR for diarrhea was 1.14 (95% CI: 0.94, 1.30) compared to those in the lowest category of exposure (≤ 3µg/g). Among boys living in the urban area, the corresponding aIRR was 1.39 (95% CI: 1.07-1.80). Among rural boys, no associations emerged. CONCLUSION: Although the results were consistent with a small positive association, the overall estimate was not precise. While urban boys in this study appeared to be more susceptible to DDE-associated diarrhea, a ready explanation for such increased susceptibility was not apparent.
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DDT/toxicidad , Diarrea/epidemiología , Diclorodifenil Dicloroetileno/toxicidad , Contaminantes Ambientales/toxicidad , Exposición Materna , Efectos Tardíos de la Exposición Prenatal/epidemiología , Diarrea/inducido químicamente , Femenino , Humanos , Incidencia , Lactante , Recién Nacido , Insecticidas/toxicidad , Masculino , México/epidemiología , Embarazo , Efectos Tardíos de la Exposición Prenatal/inducido químicamente , Clima TropicalRESUMEN
INTRODUCTION: recent studies suggest that low serum levels of polyunsaturated fatty acids omega-3 are associated with a higher prevalence of depression. OBJECTIVE: to evaluate whether low consumption of Omega-3 fatty acids is associated with a higher prevalence of depressive symptoms in a sample of college students from the Northwest of Mexico, and to assess the potential effect modification by alcohol consumption. METHODS: we conducted a cross-sectional study in a sample of 706 college students (males and females) aged 18 to 24. The presence of depressive symptoms was identified with the Depression Scale of the Center for Epidemiologic Studies (CES-D), using a cutoff point of ≥ 24. The intake of omega-3 was obtained by a food frequency questionnaire validated for Mexican population. We estimated the weekly intake of alpha-linolenic fatty acid (ALA), eicosapentaenoic (EPA) and docosahexaenoic (DHA) derived from the diet in mg/g of food. The association between omega-3 from diet and the presence of depressive symptoms was assessed using logistic regression models adjusted for potential confounders. RESULTS: 67% of the participants were females; 16.6% were classified as having depressive symptoms. A low intake of ALA and EPA + DHA was not associated with depressive symptoms before and after adjusting for confounders. Median levels of ALA (from nuts only) were significantly lower among those with depressive symptoms compared to those without these symptoms. CONCLUSIONS: in this population of Mexican college students, a low intake of omega-3 fatty acids was not associated with depressive symptoms. The potential association between nut consumption and depressive symptoms deserve more attention.
Introducción: estudios recientes sugieren que los niveles bajos de acidos grasos poliinsaturados omega-3 se relacionan con una mayor prevalencia de depresion; sin embargo, los resultados no son concluyentes. Objetivo: evaluar la asociacion entre el bajo consumo de acidos grasos omega-3 y la presencia de sintomas depresivos en jovenes universitarios del noroeste de Mexico. Métodos: se realizo un estudio transversal en una muestra de 706 universitarios de 18 a 24 anos de edad de ambos sexos. La presencia de sintomatologia depresiva se estimo con la escala de Depresion del Centro de Estudios Epidemiologicos (CES-D) empleando un punto de corte ≥ 24. El consumo semanal de acidos grasos alfalinolenico (ALA) y de eicosapentaenoico (EPA) mas docosahexaenoico (DHA) en mg/g de alimento se estimo por medio de un cuestionario de frecuencia de consumo de alimentos validado para la poblacion mexicana. La asociacion del consumo de omega-3 con la presencia de sintomas depresivos se evaluo con modelos de regresion logistica. Resultados: el 67% de los participantes fueron mujeres; en general, el 16,6% presentaron sintomatologia depresiva. El consumo bajo de ALA y EPA + DHA no se asocio con mayor prevalencia de sintomatologia depresiva antes y despues de ajustar por confusores. En aquellos casos con sintomatologia depresiva, los niveles ALA derivados solo de las nueces fueron significativamente menores. Conclusiones: en esta poblacion no se observo asociacion entre el bajo consumo de acidos grasos omega-3 y la sintomatologia depresiva. La posible asociacion entre el consumo de nueces y la sintomatologia depresiva requiere de mas estudios.
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Depresión/psicología , Ácidos Grasos Omega-3/farmacología , Adolescente , Estudios Transversales , Dieta , Femenino , Humanos , Masculino , México , Nueces , Escalas de Valoración Psiquiátrica , Estudiantes , Encuestas y Cuestionarios , Universidades , Adulto JovenRESUMEN
BACKGROUND: Prenatal exposure to 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE), the major breakdown product of DDT, has been associated with recurrent lower respiratory tract infections (LRTIs) in infants. However, epidemiological investigations are limited. OBJECTIVE: To assess the association of prenatal exposure to p,p'-DDE and p,p'-DDT with the occurrence of LRTI in boys from Chiapas, a highly exposed area of Mexico. METHODS: We analyzed data from 747 singleton boys whose prenatal exposure to p,p'-DDE and p,p'-DDT was determined in maternal serum drawn at delivery (2002-2003). LRTI (i.e., pneumonia, bronchiolitis, and other illness of the bronchi) experienced by the children were reported by their mothers during in-person interviews. The median age of the children when they were last seen was 21.4 months (quartiles 19.1 and 25.3 months). RESULTS: Median exposure to p,p'-DDE in this population was higher (2.7 µg/g lipid) than recent U.S. levels (0.20 µg/g). There were 0.19 episodes of LRTI per child-year. After adjusting for potential confounders, children in the highest category of p,p'-DDE (>9.00 µg/g) exposure compared to those in the lowest (≤ 3.00 µg/g) had an adjusted incidence rate ratio (aIRR) of LRTI of 0.77 (95% confidence interval [CI], 0.41-1.46). The corresponding aIRR for p,p'-DDT (≥ 2.00 µg/g compared to ≤ 0.25 µg/g) was 0.65 (95% CI: 0.30-1.39). CONCLUSION: An association of prenatal exposure to p,p'-DDE and p,p'-DDT with LRTI during childhood was not supported in this population with relatively high levels of exposure.
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Bronquitis/inducido químicamente , DDT/efectos adversos , Diclorodifenil Dicloroetileno/efectos adversos , Neumonía/inducido químicamente , Efectos Tardíos de la Exposición Prenatal , Adolescente , Adulto , Bronquitis/epidemiología , Preescolar , Femenino , Estudios de Seguimiento , Humanos , Lactante , Masculino , México/epidemiología , Neumonía/epidemiología , Embarazo , Adulto JovenRESUMEN
Recent data suggest that prenatal exposure to p,p'-DDE may reduce height and increase body mass index (BMI) in childhood, thus potentially raising the risk of adult health problems. The association between prenatal DDE exposure and growth was evaluated in 788 boys from Chiapas, an area of Mexico where DDT was recently used. The median DDE levels in maternal serum at birth (2002-2003) were 2.7 microg/g lipid. 2633 measurements of height (cm) and weight (kg) were obtained in 2004-2005. The median age of the children during follow-up was 18 months (quartiles 14 and 22 months). Height and body mass index (kg/m(2)) were age-standardized and expressed as standard deviation scores (SDS). Multivariate random-effect models for longitudinal data were fitted and predicted height and BMI SDS were estimated from the adjusted models. Overall, associations between prenatal DDE level and height or BMI SDS at any given age were not observed. For example, the predicted values showed that children with the highest exposure (DDE: >9.00 microg/g) compared to those least exposed (DDE: <3.01 microg/g) grew similarly and they had a BMI SDS similar to the referent group. The results do not support the prior findings of an association of DDE exposure with childhood height or BMI.
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Diclorodifenil Dicloroetileno/análogos & derivados , Exposición Materna , Adolescente , Adulto , Peso al Nacer/efectos de los fármacos , Estatura/efectos de los fármacos , Índice de Masa Corporal , DDT/sangre , Diclorodifenil Dicloroetileno/sangre , Diclorodifenil Dicloroetileno/toxicidad , Monitoreo del Ambiente , Femenino , Humanos , Lactante , Recién Nacido , Estudios Longitudinales , Masculino , Exposición Materna/estadística & datos numéricos , México , Embarazo , Adulto JovenRESUMEN
Breastfed children have lower risk of infectious diseases, post-neonatal mortality and chronic diseases later in life. Because epidemiologic studies usually rely on reported history of previous breastfeeding, data on the accuracy and precision of recalled histories allow improved interpretation of the epidemiologic findings. We evaluated the reliability of two reported breastfeeding durations in 567 reproductive-aged women from Mexico using information obtained from nearly identical sets of questions applied at different times after weaning. We compared differences between reports, and examined the intraclass correlation coefficient (ICC) for any and for exclusive breastfeeding (EBF). Logistic regression was used to evaluate the determinants of poor recall (difference between reports of >20%). The reliability of duration of any breastfeeding was high (ICC 0.94). Overall, differences between reports of duration were usually <1 month, and for 385/567, the difference was < or =0.5 months. Predictors of poorer recall were having > or =4 children, and time between reports of >2 months. The only predictor of better recall was greater age of the baby at weaning. The reliability of EBF duration was lower (ICC 0.49). In this population with a relatively long duration of breastfeeding, reliability of any breastfeeding duration was high. Age, education and previous breastfeeding were not important predictors of recall, in contrast to findings in earlier studies. Consistent with previous reports, however, parity and length of recall were associated with poorer recall of duration of any breastfeeding. Future studies that use reported breastfeeding duration may want to consider the effect of these variables on recall.
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Lactancia Materna/estadística & datos numéricos , Adolescente , Adulto , Factores de Edad , Peso al Nacer , Femenino , Estudios de Seguimiento , Edad Gestacional , Humanos , Recién Nacido , Masculino , Recuerdo Mental , México , Pobreza , Reproducibilidad de los Resultados , Población Rural , Encuestas y Cuestionarios , Factores de Tiempo , Población Urbana , DesteteRESUMEN
BACKGROUND: Higher levels of 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE), the major degradation product of 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT), have been related to shorter duration of breast-feeding in previous studies. If DDE truly shortens lactation, this has public health importance regarding infant mortality and the use of DDT for malaria control. OBJECTIVE: Our aim was to assess the relationship of maternal DDE concentrations with length of subsequent lactation. METHODS: We conducted a relatively large study in a highly exposed area of Mexico. We followed 784 mother-son pairs to determine length of lactation. DDE and DDT were measured in maternal serum obtained within a day of delivery. We fit proportional hazard models with and without stratifying by previous breast-feeding, because an association of DDE with duration of lactation among those who breast-fed previously could be attributed to a noncausal mechanism. RESULTS: Compared with those with DDE concentrations < or = 3.00 microg/g, the adjusted hazard ratios of weaning according to DDE category were, for concentrations 3.01-6.00 microg/g, 1.27 [95% confidence interval (CI), 1.04-1.55]; for concentrations 6.01-9.00 microg/g, 1.23 (95% CI, 0.92-1.63); and for concentrations > 9.00 microg/g, 1.17 (95% CI, 0.92-1.49). The corresponding ratios for women who previously breast-fed were 1.40 (95% CI, 1.06-1.87); 1.91 (95% CI, 1.24-2.93); and 1.76 (95% CI, 1.22-2.53). Those for women who had not breast-fed previously were 1.14 (95% CI, 0.86-1.52); 0.90 (95% CI, 0.61-1.31); and 0.91 (95% CI, 0.66-1.26). CONCLUSIONS: Data from our relatively large study in a highly exposed area of Mexico did not support the hypothesis that exposure to DDE shortens length of lactation. The association seen in women who previously breast-fed was likely attributed to a noncausal mechanism. Nonetheless, whether DDT has other important adverse effects on humans is still an open question.
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DDT/toxicidad , Diclorodifenil Dicloroetileno/toxicidad , Lactancia/efectos de los fármacos , Adolescente , Adulto , Exposición a Riesgos Ambientales , Femenino , Humanos , México , Embarazo , Modelos de Riesgos ProporcionalesRESUMEN
Development of the perineum as well as the external genitalia is determined by dihydrotestosterone, resulting in a greater anogenital distance (AGD) in males than females. In animal experiments with hormonally active agents, anogenital distance is used as a bioassay of fetal androgen action. Use of anogenital distance in human studies has been rare. Because anogenital distance has been an easy-to-measure, sensitive outcome in animal studies, we developed an anthropometric protocol for measurement of anogenital distance in human males. In this paper we describe the method for measurement of three anogenital distances, their reliability, and an assessment of predictors for each in the context of an epidemiological study. We compare the reliabilities and predictors to those for stretched penis length and penis width. A cross-sectional study of 781 newly delivered male infants was conducted in 2002-03 in Chiapas, Mexico. Replicate measures were obtained on nearly all subjects. The reliability of the measures of anogenital distance (0.82-0.91) were higher than for stretched penis length (0.78) and width (0.75). Birthweight and gestational length were more strongly related to anogenital distance than to penis length. Anogenital distance was not related to penis length (r = 0.03). Our large study clearly shows that AGD can be measured well in newborn males, and that the measurements were more reliable than those of penis length. Whether AGD measures in humans relate to clinically important outcomes, however, remains to be determined, as does its utility as a measure of androgen action in epidemiological studies.
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Antropometría/métodos , Pene/anatomía & histología , Perineo/anatomía & histología , Adulto , Canal Anal/anatomía & histología , Andrógenos/fisiología , Peso al Nacer/fisiología , Estudios Transversales , Femenino , Edad Gestacional , Humanos , Recién Nacido , Masculino , México , Tamaño de los Órganos , Reproducibilidad de los Resultados , Estadística como AsuntoRESUMEN
The insecticide 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) is still used for disease control in some areas, resulting in high levels of human exposure. The main degradation product of DDT is 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE), an antiandrogen. In animal experiments, in utero exposure to DDE decreases anogenital distance in male offspring. In these models, anogenital distance serves as a measure of fetal androgen action. The authors designed the present study to examine the hypothesis that in utero exposure to DDE decreases anogenital distance in newborn human males. A cross-sectional study of 781 newly delivered male infants was conducted in 2002-2003 in Chiapas, México, where DDT had recently been used for malaria control. Measurements of anogenital distance and penile dimensions were taken, and a sample of the mother's blood was drawn. In this population, the range of serum DDE levels was large (0.8-398 microg/liter). The authors, using two-sided tests, found no evidence that exposure in utero to DDE was related to reduced androgen action as reflected by anogenital distance or penile dimensions at birth. If DDE has important antiandrogenic action in humans, it may be manifest only at higher levels of exposure or via effects on other outcomes.
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Antagonistas de Andrógenos/toxicidad , DDT/toxicidad , Diclorodifenil Dicloroetileno/toxicidad , Enfermedades del Sistema Endocrino/inducido químicamente , Genitales Masculinos/anomalías , Exposición Materna/efectos adversos , Anomalías Urogenitales/inducido químicamente , Adolescente , Adulto , Estudios Transversales , Biología Evolutiva , Enfermedades del Sistema Endocrino/epidemiología , Femenino , Genitales Masculinos/efectos de los fármacos , Humanos , Incidencia , Recién Nacido , Masculino , Intercambio Materno-Fetal , México/epidemiología , Embarazo , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Anomalías Urogenitales/epidemiologíaRESUMEN
We compared the median age at menarche in two developing countries to determine whether early age at menarche varies across body mass index (BMI), socioeconomic level, and urban/rural residence in Mexican and Egyptian adolescents. Questionnaire data and weight and height measurements were collected from 4,143 Mexican and 493 Egyptian adolescent girls (age, 10-19 years). Statistical analysis included Pearson chi-squared, Student t-test, and multiple logistic regression models. Median age at menarche was 12 years (range, 8-19 years) for Mexican girls and 13 years (range, 9-16) for Egyptian girls. In both countries, the odds of undergoing menarche at an earlier age were higher among adolescents with the following characteristics: overweight or obesity, as compared to those with a normal BMI (Mexican adolescents, OR = 1.45, 95% CI 1.25-1.69; Egyptian adolescents, OR = 2.20, 95% CI 1.21-4.03); living in urban versus rural areas (OR = 1.38, 95% CI 1.19-1.61 and OR = 1.38, 95% CI 0.74-2.59, respectively); high socioeconomic level versus the lowest level (OR = 1.46, 95% CI 1.22-1.74 and OR = 1.41, 95% CI 0.67-2.98, respectively). The associations between early age at menarche and urban residence or high socioeconomic level were statistically significant only in Mexican adolescents. Menarche at an earlier age was most strongly associated with overweight and obesity in both Mexican and Egyptian adolescents, while urban residence and high socioeconomic level were significantly associated only in Mexican adolescents.