الملخص
La información sobre biomarcadores óseos en adolescentes y adultas durante el periodo posparto es incierta, por lo que el objetivo de este artículo fue analizar el patrón de biomarcadores óseos en adolescentes y adultas a 15, 90, 180 y 365 días posparto (dpp) y su asociación con la densidad mineral ósea (DMO) y lactancia materna. Se realizó un estudio de cohorte en 32 madres adolescentes ≤17 años y 41 adultas de 18 a 29 años de edad en el primer año posparto. Se realizaron medidas antropométricas, DMO y biomarcadores óseos y así como datos del tipo y la duración de lactancia. Como resultados se encontró asociación entre la concentración basal de N-telopéptidos ≤24 μg/L y mayor aumento de DMO. Las adolescentes tuvieron mayor concentración de N-telopéptidos (p≤0.004) y menor concentración de osteocalcina (5±3 vs13±4, p <0.001) que las adultas. La lactancia no afectó el cambio de DMO (p>0.050), ni de biomarcadores óseos. La osteocalcina se asoció con el cambio en DMO (p<0.040). La prolactina fue mayor entre las que practicaron lactancia materna exclusiva (p<0.001). A menor edad menores concentraciones de osteocalcina (p<0.001) y mayores concentraciones de N-telopéptidos (p<0.001). Se concluyó que a menor concentración de N-telopéptidos y mayor de osteocalcina hubo un mayor aumento de DMO, lo cual implica menor aumento de ésta en el grupo de adolescentes. La lactancia no afectó la DMO.
The objective of this study was to describe the trend of bone biomarkers in adults and adolescents women at 15, 90, 180 and 365 postpartum days (ppd) and its relation with bone mineral density (BMD). It was a prospective cohort of 32 teenagers ≤17 and 41 women from 18 to 29 years old. We evaluated diet, anthropometry, BMD, bone biomarkers and hormonal profile. In all, the concentration of N-telopeptide was higher at 15 days postpartum decreasing during first year postpartum, but adolescents had the highest concentration. The lowest N-telopeptide concentration was associated with highest increasing of the BMD. Osteocalcin concentration was lower in adolescents than in adults women (5 ± 3 vs 13 ± 4 ng/mL, p<0.001) during first year postpartum. Exclusive breastfeeding did not affect the BMD (p>0.050) or bone biomarkers. Osteocalcin concentration was positively associated with bone BMD (p<0.040), breastfeeding did not affect osteocalcin concentrations. Prolactin was higher among women who breastfed exclusively (p<0.001). Age and breastfeeding inversely correlated with bone biomarkers (p<0.001) N-telopeptide and PTHi respectively. We concluded that a lower N-telopeptide concentration and a higher osteocalcin concentration were associated with a higher increasing of BMD, so then, adolescents showed the lowest recovery of the BMD. Breastfeeding does not affect the BMD.
الموضوعات
Adolescent , Adult , Female , Humans , Male , Young Adult , Bone Density/physiology , Collagen Type I/blood , Lactation/blood , Osteocalcin/blood , Peptides/blood , Postpartum Period/blood , Absorptiometry, Photon , Biomarkers/blood , Cohort Studies , Lactation/physiology , Postpartum Period/physiologyالملخص
Calcium metabolism of the mother is modified during pregnancy because of the mineralization of the fetus skeleton. OBJECTIVE: To evaluate the association of calcium intake and bone demineralization during pregnancy. MATERIAL AND METHODS: At each trimester of pregnancy a validated food frequency intake questionnaire was administered to assess individual daily calcium intake in a cohort of 206 pregnant women, residents of Mexico City. Samples of urine were collected to measure levels of the cross-linked N-telopeptide of type I collagen (NTx), which is a biomarker of bone resorption. The association between calcium ingestion and bone resorption was analyzed using random effects models; non-linear associations were explored using generalized additive models. RESULTS: Progressive increases in NTx levels were observed during pregnancy; with mean and standard deviation (SD) values during the first, second and third trimester of 76.50 (SD=38), 101.02 (SD=48.86) and 144.83 (SD=61.33) nmol BCE/mmol creatinine, respectively. Higher dietary calcium intake was associated with lower bone resorption (β=-0.015; p<0.05). The association between age and NTx showed a non-linear trend with an inflexion point around 33 years: increase in maternal age below that point was associated with a decrease in bone resorption, while in older women the increase in age was associated with an increased resorption. CONCLUSIONS: Our results suggest that calcium ingestion, specifically from dairy products, reduces bone resorption during pregnancy. For each 300mg (a glass of milk) of calcium intake there is an estimated reduction in NTx level of 4.8 nmol BCE/mmol of creatinine (p<0.05).
El metabolismo de calcio es modificado durante el embarazo debido a la mineralización del esqueleto del feto. OBJETIVO: Evaluar la asociación entre la ingesta de calcio y la desmineralización ósea durante el embarazo. MATERIAL Y MÉTODOS: Se administró un Cuestionario de Frecuencia de Consumo de alimentos en cada trimestre del embarazo para evaluar el consumo de calcio en una cohorte de 206 mujeres residentes de la Ciudad de México. Se recolectaron muestras de orina para medir los niveles de N-telopéptido de colágeno tipo I (NTx), biomarcador de resorción. Se hicieron modelos de efectos aleatorios; se estudiaron asociaciones no lineales utilizando modelos aditivos generalizados. RESULTADOS: Se observó aumento progresivo en los niveles de NTx durante el embarazo. El mayor consumo de calcio se asoció con una menor resorción ósea (β=- 0.015, p<0,05). CONCLUSIONES: Los resultados sugieren que la ingestión de calcio reduce la resorción ósea en el embarazo.