The effect of hypohydration on endothelial function in young healthy adults.

PURPOSE: Hypohydration has been suggested as a predisposing factor for several pathologies including cardiovascular diseases (CVD). While CVD are the leading cause of death worldwide, no study has investigated whether acute hypohydration affects endothelial function and cardiovascular function. METHODS: Ten young, healthy males participated in this crossover study (age: 24.3 ± 2.3 year; weight: 80.8 ± 5.3 kg; BMI: 24.3 ± 0.4 kg m-2). Each subject completed two measurements of endothelial function by flow-mediated dilation (FMD) in euhydrated and hypohydrated state separated by 24 h. Following baseline assessment of hydration status and FMD, the subjects completed 100 min of low-intensity intermittent walking exercise to achieve hypohydration of -2 % of individual body mass. For the rest of the day, a standardized, low water content diet was provided. The following morning, hydration markers and endothelial function were recorded. RESULTS: Hypohydration by -1.9 ± 0.1 % of body mass resulted in decreased plasma volume by -3.5 ± 1.8 % and increased plasma osmolality by 9 ± 2 mmol kg-1 (P < 0.001). FMD as a response to hypohydration decreased by -26.8 ± 3.9 % (P < 0.05). CONCLUSION: The data suggested that a small degree of hypohydration induced by moderate exercise and fluid restriction significantly impaired endothelial function.

The effect of high doses of folic acid and iron supplementation in early-to-mid pregnancy on prematurity and fetal growth retardation: the mother-child cohort study in Crete, Greece (Rhea study).

PURPOSE: We examined whether high doses of folic acid and iron supplementation in early-to-mid pregnancy affect the risk of preterm birth, low birth weight, and small for gestational age neonates, in the mother-child cohort in Crete, Greece (Rhea study). METHODS: We included 1,279 women with singleton pregnancies with complete data on supplements use in early-to-mid pregnancy and birth outcomes. Anthropometric measurements at birth were obtained from medical records. Red blood cell folate concentrations in cord blood were measured in a subsample of the study population (n = 58). RESULTS: Sixty-six percent of the study participants reported high doses of supplemental folic acid use (5 mg/day), while 21 % reported excessive doses of folic acid use (>5 mg/day) in early-to-mid pregnancy. Daily intake of 5-mg supplemental folic acid was associated with a 31 % decrease in the risk of preterm birth (RR, 0.69; 95 % CI, 0.44, 0.99), 60 % decrease in the risk of delivering a low birth weight neonate (RR, 0.40; 95 % CI, 0.21, 0.76), and 66 % decrease in the risk of delivering a small for gestational age (SGA) neonate (RR, 0.34; 95 % CI, 0.16, 0.73). Daily doses of iron supplementation more than 100 mg were associated with a twofold increased risk for SGA neonates (RR, 2.14; 95 % CI, 0.99, 5.97). CONCLUSION: These findings suggest that high daily doses of supplementary folic acid in early-to-mid pregnancy may be protective for preterm birth, low birth weight, and small for gestational age neonates, while high daily doses of supplementary iron may be harmful for fetal growth.

Effect of high doses of folic acid supplementation in early pregnancy on child neurodevelopment at 18 months of age: the mother-child cohort 'Rhea' study in Crete, Greece.

OBJECTIVE: To investigate whether high doses of folic acid supplementation in early pregnancy are associated with child neurodevelopment at 18 months of age. DESIGN: The study uses data from the prospective mother-child cohort 'Rhea' study. Pregnant women completed an interviewer-administered questionnaire on folic acid supplementation at 14-18 weeks of gestation. Neurodevelopment at 18 months was assessed with the use of the Bayley Scales of Infant and Toddler Development (3rd edition). Red-blood-cell folate concentrations in cord blood were measured in a sub-sample of the study population (n 58). SETTING: Heraklion, Crete, Greece, 2007-2010. SUBJECTS: Five hundred and fifty-three mother-child pairs participating in the 'Rhea' cohort. RESULTS: Sixty-eight per cent of the study participants reported high doses of supplemental folic acid use (5 mg/d), while 24 % reported excessive doses of folic acid (>5 mg/d) in early pregnancy. Compared with non-users, daily intake of 5 mg supplemental folic acid was associated with a 5-unit increase on the scale of receptive communication and a 3·5-unit increase on the scale of expressive communication. Doses of folic acid supplementation higher than 5 mg/d were not associated with additional increase in the neurodevelopmental scales. CONCLUSIONS: This is the first prospective study showing that high doses of supplementary folic acid in early pregnancy may be associated with enhanced vocabulary development, communicational skills and verbal comprehension at 18 months of age. Additional longitudinal studies and trials are needed to confirm these results.