Avalia??o da concentra??o de vitamina A materna e de neonatos prematuros e a termo

• Main Author: Lima, Mayara Santa Rosa
• Other Authors: 18095640425
• Language: Portuguese
• Published: Universidade Federal do Rio Grande do Norte 2016
• Subjects: CNPQ::CIENCIAS BIOLOGICAS::BIOQUIMICA; Vitamina A; Retinol; Soro; Cord?o umbilical; Leite humano; Prematuro
• Online Access: http://repositorio.ufrn.br/handle/123456789/20054

Submitted by Automa??o e Estat?stica ([e-mail]) on 2016-03-10T20:24:54Z No. of bitstreams: 1 MayaraSantaRosaLima_DISSERT.pdf: 1762065 bytes, checksum: 81b2ba7e141b5e4144aae1950f65a16e (MD5) === Approved for entry into archive by Arlan Eloi Leite Silva ([e-mail]) on 2016-03-17T00:16:56Z (GMT) No. of bitstreams: 1 MayaraSantaRosaLima_DISSERT.pdf: 1762065 bytes, checksum: 81b2ba7e141b5e4144aae1950f65a16e (MD5) === Made available in DSpace on 2016-03-17T00:16:56Z (GMT). No. of bitstreams: 1 MayaraSantaRosaLima_DISSERT.pdf: 1762065 bytes, checksum: 81b2ba7e141b5e4144aae1950f65a16e (MD5) Previous issue date: 2015-05-26 === A vitamina A ? um nutriente essencial em diversos processos fisiol?gicos, como crescimento e desenvolvimento, de modo que um adequado estado nutricional nesse nutriente ? fundamental na gesta??o e lacta??o. Mulheres lactantes e crian?as em aleitamento materno s?o consideradas grupos de risco para a defici?ncia de vitamina A e alguns fatores podem aumentar o risco de hipovitaminose, como a prematuridade. O objetivo deste trabalho foi avaliar a concentra??o de vitamina A em lactantes e rec?m-nascidos pr?-termo e a termo, por meio da determina??o do retinol no soro materno, no soro do cord?o umbilical e no leite materno coletado at? 72 horas p?s-parto. Foram recrutadas 182 parturientes, divididas em grupo pr?-termo (GPT; n=118) e grupo termo (GT; n=64). No grupo pr?- termo tamb?m foram analisadas amostras de leite de transi??o (7?-15? dia; n=68) e leite maduro (30?-55? dia; n=46). O retinol foi analisado por cromatografia l?quida de alta efici?ncia (CLAE). A concentra??o materna de retinol s?rico foi 48,6 ? 12,3 ?g/dL no GPT e 42,8 ? 16,3 ?g/dL no GT (p<0,01). O retinol no soro do cord?o umbilical foi 20,4 ? 7,4 ?g/dL no GPT e 23,2 ? 7,6 ?g/dL no GT (p>0,05). Entre os rec?m-nascidos, 43% dos prematuros e 36% dos a termo apresentaram baixos n?veis de retinol s?rico no cord?o umbilical (<20 ?g/dL). No colostro, lactantes pr?- termo e termo apresentaram m?dia de retinol de 100,8 ? 49,0 ?g/dL e 127,5 ? 65,1 ?g/dL, respectivamente (p<0,05). A m?dia de retinol no leite pr?-termo aumentou para 112,5 ? 49,7 ?g/dL na fase de transi??o e reduziu para 57,2 ? 23,4 ?g/dL no leite maduro, diferindo significativamente entre todas as fases (p<0,05). Ao comparar com a recomenda??o de ingest?o de vitamina A (400 ?g/dia) o leite colostro do GT atingiu a recomenda??o para lactentes, por?m no GPT a recomenda??o n?o foi atingida em nenhuma das fases. As m?es de rec?m-nascidos prematuros possu?am concentra??o s?rica de retinol superior ? de m?es a termo, entretanto, isso n?o foi refletido no retinol do soro do cord?o umbilical, uma vez que os prematuros apresentaram menor concentra??o da vitamina. Tal condi??o pode ser explicada devido ? menor hemodilui??o fisiol?gica materna e transfer?ncia placent?ria de retinol para o feto durante a gesta??o pr?-termo. A compara??o do retinol no colostro evidenciou menor concentra??o no GPT, no entanto na fase de transi??o houve um aumento importante do conte?do de retinol liberado pela gl?ndula mam?ria de lactantes pr?-termo. Essa situa??o evidencia uma adapta??o fisiol?gica pr?pria da prematuridade, provavelmente no sentido de contribuir mais para a forma??o das reservas hep?ticas de retinol dos lactentes prematuros. === Vitamin A is an essential nutrient for many physiological processes such as growth and development, so that their adequate nutritional state is essential during pregnancy and lactation. Lactating women and children in breastfeeding are considered risk groups for vitamin A deficiency and some factors may increase the risk of vitamin A deficiency, such as prematurity. The aim of this work was to evaluate the vitamin A concentration in preterm and term lactating women and newborns by determination of retinol in maternal serum, umbilical cord serum and breast milk collected until 72 hours postpartum. 182 mothers were recruited and divided into preterm group (GPT; n = 118) and term group (GT, n = 64). In preterm group were also analyzed transition milk (7th-15th day; n = 68) and mature milk (30th-55th day; n = 46) samples. Retinol was analyzed by high-performance liquid chromatography (HPLC). Maternal retinol concentration in serum was 48.6 ? 12.3 ?g/dL in GPT and 42.8 ? 16.3 ?g/dL in the GT (p <0.01). Cord serum retinol was 20.4 ? 7.4 ?g/dL in GPT and 23.2 ? 7.6 ?g/dL in GT (p> 0.05). Among newborns, 43% of premature and 36% of term had low levels of serum retinol in umbilical cord (<20 ?g/dL). In colostrum, the retinol in preterm and term groups had an average of 100.8 ? 49.0 ?g/dL and 127.5 ? 65.1 ?g/dL, respectively (p <0.05). The retinol average in preterm milk increased to 112.5 ? 49.7 ?g/dL in transition phase and decreased to 57.2 ? 23.4 ?g/dL in mature milk, differing significantly in all stages (p <0.05). When comparing with the recommendation of vitamin A intake (400 ?g/day) GT colostrum reached the recommendation for infants, but in GPT the recommendation was not achieved at any stage. Mothers of premature infants had higher serum retinol than mothers at term; however, this was not reflected in serum retinol of umbilical cord, since premature had lower concentration of retinol. Such condition can be explained due to lower maternal physiological hemodilution and placental transfer of retinol to the fetus during preterm gestation. Comparison of retinol in colostrum showed lower concentrations in GPT; however the transition phase there was a significant increase of retinol content released by the mammary gland of preterm mothers. This situation highlights a specific physiological adaptation of prematurity, likely to more contribute to formation of hepatic reserves of retinol in premature infants.