Nutrition Research, Vol. 20, No. 10, pp. 1389-1394, 2000 Copyright © 2000 Elsevier Science Inc. Printed in the USA. All rights reserved 0271-5317/00IS-see front matter
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FOLATE DEFICIENCY IS ASSOCIATED WITH OBESITY AND ANEMIA IN MEXICAN URBAN WOMEN Esther Casanueva 1. Alej andra Drij anski** Ana Cecilia Femfindez-Gaxiola** Carlos Meza* Frania Pfeffer* Departamento de Investigaci6n en Nutrici6n, Instituto Nacional de Perinatologia, M6xico ** Departamento de Salud, Universidad Iberoamericana, M6xico. ABSTRACT The objective was to evaluate folate status in non-pregnant, non-lactating (NPNL) urban Mexican women of childbearing age, determining the prevalence of deficiency and related risk factors. One hundred and seventeen NPNL women who attended the outpatient clinic of a teaching gyneco obstetric hospital in Mexico City were evaluated in a cross-sectional study. Their folate (erythrocyte and plasma concentrations), iron (hemoglobin and ferritin concentrations) and vitamin B12 (plasma concentrations) status was evaluated. None of these women reported consuming vitamins, alcohol or drugs that could interfere with the metabolism of this nutrients. Anemia prevalence was close to 12% (hemoglobin < 130 g/L) and the most frequent isolated deficiency found was of folic acid (20.5%), followed by iron deficiency (13.7 %). Only 11.9% had vitamin B12 deficiency judged by plasma concentrations. The most important risk factors for folate deficiency were the presence of anemia (Odds ratio 4.16, 95% CI = 1.3 - 13.14) and obesity (odds ratio 50.00, 95% CI = 13.39 - 186.95) © 20(~,ElsevierScience lnc
Key words: Women, anemia, folic acid, vitamin B12, obesity, Mexico. INTRODUCTION In Mexico the prevalence of anemia in women during their reproductive years is 12%, according to the National Survey of Nutrition I There are only few studies where the causes of anemia have been explored, meaning, that the available information on the iron, folic acid and vitamin B12 status of non-pregnant, non-lactating (NPNL) women of reproductive age is scarce. According to review by Rosado and collages 2,3 and Mora, 4 there are only two identifiable studies on this subject in the Mexican population. One was performed in 1994 by Black et al, 5 in a rural community with 71 NPNL women, in which hemog61obin, ferritin and plasma B12 and folate were measured. The other was performed by Kaufer et al, where ferritin and hemoglobin concentrations were measured in NPNL urban women.
i Corresponding author: Esther Casanueva phone (525) 540 29 47 FAX (525) 5200034 email [email protected]
E. CASANUEVA et al.
The role that folic acid plays m neural tube defects (NTD) and in pre and postnatal growth retardation has been a subject of interest in recent years] Folic acid supplementation may mask pernicious anemia, causing neurological alterations. 8 In Anglo populations, 9'1° women's obesity is an important risk factor for NTD, but the causal mechanism is unknown. Considering that in Mexico there has been an increase in the prevalence of overweight in the general population and in childbearing age women 11 and that NTD are more frequent in Mexico than in other populations ~2the objective of this study was to evaluate the folic acid status of non-pregnant, non-lactating (NPNL) urban Mexican women, the prevalence of deficiency and some related risk factors. MATERIAL AND METHODS. Non pregnant and non-iactating women from the sterility outpatient clinic of the Instituto Nacional de Perinatologia (INPer), were invited to participate in this study. Exclusion criteria included sterility cause related to any metabolic disease (e.g. diabetes mellitus, hypothyroidism) that could interfere with nutrition, chronic disease, or use of vitamin supplements, oral contraceptive agents, alcohol or drugs that could interfere with iron, folic acid or vitamin B12 metabolism. 8 The women included wh~ the ones that the sterility cause was due to male problems or mechanical causes (oviduct obstruction, etc.). All this women had normal estrogen status. Participants received a detailed description of the study protocol and signed informed consent forms. The Research and Ethics Board of the INPer (Mexico) approved the study. To determine body mass index (BMI, kg/m2), weight and height were evaluated in all women by standardized personnel (undergraduate students of Nutrition and Food Sciences). According to the National Institutes of Health of the USA 13 the cut-off point for obesity is BMI >27.3 kg/m. 2 A venous blood sample ( 5 mL) was taken from fasted subjects and distributed in two tubes, one with EDTA and one without anticoagulant. Within a 3 hour period after the sample was taken hemoglobin determinations were performed by the cyanomethahemoglobin test. TM The CV for hemoglobin was 2.3%. Plasma and erythrocytes were stored at - 70 °C to be assayed later. Plasma ferritin was determined by immunoassay (Behring Diagnostics), while plasma vitamin B12 and folate and erythrocyte folate (RBC folate) were determined by a solid phase no boil dual count radioimmunoassay kit (Diagnostic Products Co)] 5 All measurements were assayed in duplicate. The coefficients of variation for plasma ferritin, plasma folate, RBC folate and plasma vitamin B12 were less than 5%. The criteria used by the World Health Organization and the Intemational Anemia Consultative Group, 1617 corrected for Mexico City altitude (2400 m above sea level) was used to identify anemia (