RESUMO
ABSTRACT Chile, and several Latin American countries, use the Atalah standard to assess nutritional status during pregnancy. However, this standard (underweight: pre-pregnancy body mass index (BMI)<20 kg/m2 and normal weight: pre-pregnancy BMI= 20-24.9 kg/m2) differ from those recommended by the US Institute of Medicine (IOM2009) (underweight: BMI<18.5 kg/m2 and normal weight: 18.5-24.9 kg/m2). Using a large population database from a Chilean public hospital, we compared the prevalence of underweight and normal weight at the beginning of pregnancy with Atalah and IOM2009 standards. Additionally, we evaluated the performance of both standards in detecting adverse neonatal outcomes and gestational weight gain. Methods: Data from clinical records of single birth pregnancies (n= 59,476) at the Sótero del Río Hospital, between 2003-2012 were collected. We compared 1. nutritional status, 2. proportion of excessive gestational weight gain, 3. association between nutritional status and neonatal outcomes (large/small for gestational age, low birth weight, preterm birth and macrosomia), using logistic regression models, and 4. Sensitivity, specificity, and predictive values to predict adverse neonatal outcomes per nutritional status. Results: Pre-pregnancy underweight decreased from 8.6% to 2.5% and women with BMI between 18.5-19.9kg/m2, who exceeded the recommended gestational weight gain increased from 32.7% to 49.2% when using IOM2009 instead of Atalah. Both standards showed low sensitivity, but the IOM2009 cut-off points showed better specificity for identifying healthy newborns. Conclusion: The cut-off points recommended by the IOM2009 better identify the prevalence of underweight and normal weight during pregnancy without increasing neonatal risk. This study supports the recent change of the Ministry of Health in adopting the WHO cut-off points during pregnancy.
RESUMEN Chile y diversos países Latinoaméricanos utilizan el estándar de Atalah para evaluar el estado nutricional (EN) durante el embarazo. Sin embargo, los puntos de corte de este estándar (bajo peso, BP: índice de masa corporal pre-gestacional (IMC)<20 kg/m2 y normal, NP: IMC pregestacional= 20-24,9 kg/m2) difieren de los recomendados por el Instituto de Medicina de EE.UU. (IOM2009) (BP: BMI<18.5kg/m2 and NP: 18,5-24,9 kg/m2). Con datos obtenidos desde el Hospital Sótero del Río, nosotros evaluamos la prevalencia de BP y NP al comienzo del embarazo con los estándares de Atalah e IOM2009. Adicionalmente, nosotros comparamos el comportamiento de ambos estándares en detectar resultados neonatales (RN) adversos y en la clasificación de la ganancia de peso gestacional (GPG). Métodos: Se obtuvieron datos de embarazos simples entre 2003-2012, (n= 59.476). Nosotros comparamos: 1. Prevalencia de EN, 2. Proporción de excesiva GPG, 3. Asociación entre EN y RN, usando modelos de regresión logística, y 4. Sensibilidad, especificidad y valores predictivos para predecir RN según EN. Resultados: La prevalencia de BP pregestacional disminuyó de 8,6% a 2,5% y las mujeres con IMC entre 18,5-19,9 kg/m2 que excedieron la GPG recomendada, incrementaron desde 33% a 50% cuando se utilizó el estándar IOM2009 en vez de Atalah. Ambos estándares mostraron baja sensibilidad, pero IOM2009 mostró mejor especificidad para identificar recién nacidos saludables. Conclusión: Estandar IOM2009 identifica con mayor precisión la prevalencia de BP y NP durante la gestación sin incrementar el riesgo neonatal. Este estudio respalda el reciente cambio del MINSAL al adoptar los puntos de corte de la OMS durante el embarazo.
RESUMO
This study aimed to evaluate the longitudinal association of vitamin D status with glycaemia, insulin, homoeostatic model assessment of insulin resistance, adiponectin and leptin. A prospective cohort with 181 healthy, pregnant Brazilian women was followed at the 5th-13th, 20th-26th and 30th-36th gestational weeks. In this cohort, 25-hydroxyvitamin D (25(OH)D) plasma concentrations were analysed using liquid chromatography-tandem MS. Vitamin D status was categorised as sufficient or insufficient using the Endocrine Society Practice Guidelines (≥75/<75 nmol/l) and the Institute of Medicine (≥50/<50 nmol/l) thresholds. Linear mixed-effect regression models were employed to evaluate the association between vitamin D status and each outcome, considering interaction terms between vitamin D status and gestational age (P<0·1). At baseline, 70·7 % of pregnant women had 25(OH)D levels <75 nmol/l and 16 % had levels <50 nmol/l. Women with sufficient vitamin D status at baseline, using both thresholds, presented lower glycaemia than those with insufficient 25(OH)D. Pregnant women with 25(OH)D concentrations <75 nmol/l showed lower insulin (ß=-0·12; 95 % CI -0·251, 0·009; P=0·069) and adiponectin (ß=-0·070; 95 % CI -0·150, 0·010; P=0·085) concentrations throughout pregnancy than those with 25(OH)D levels ≥75 nmol/l. Pregnant women with 25(OH)D <50 nmol/l at baseline presented significantly higher leptin concentrations than those with 25(OH)D levels ≥50 nmol/l (ß=-0·253; 95 % CI -0·044, 0·550; P=0·095). The baseline status of vitamin D influences the biomarkers involved in glucose metabolism. Vitamin D-sufficient women at baseline had higher increases in insulin and adiponectin changes throughout gestation than those who were insufficient.