Ji-Yun Hwang

Association of maternal folate nutrition and serum C-reactive protein concentrations with gestational age at delivery

Background/objectives:C-reactive protein (CRP) is the most extensively studied inflammatory risk marker, and elevated serum CRP concentrations in pregnant women are known to be associated with subsequent development of preeclampsia and preterm delivery. Researchers have suggested that folate intake may help to control the inflammation process. We examined whether folate nutrition modifies the relationship between serum CRP concentration and gestational age at delivery.Subjects/methods:Serum CRP concentrations were analyzed in 815 pregnant women between 12 and 28 weeks of gestation. Dietary intakes were assessed using a 24-h dietary recall. The serum folate and high-sensitivity CRP concentrations were analyzed by radioassay and latex agglutination tests, respectively.Results:Serum CRP concentration was negatively correlated (P<0.001) with gestational age at delivery. Serum folate concentration was negatively correlated (P<0.01) with serum CRP concentration, and total dietary folate intake was positively correlated (P<0.001) with serum folate concentration. Multiple regression analysis after adjustment for covariates revealed that maternal CRP concentrations were negatively associated with gestational age at delivery; these negative associations existed only when folate intake during pregnancy was below the Korean estimated average requirements (520u2009μg dietary folate equivalent per day), and serum folate concentrations were above the normal (6u2009ng/ml).Conclusions:We found that adequate maternal folate intake during pregnancy may have a beneficial role against shorter gestational age at delivery, which is associated with higher serum CRP concentrations in pregnant women.

Maternal iron intake at mid-pregnancy is associated with reduced fetal growth: results from Mothers and Children’s Environmental Health (MOCEH) study

BackgroundIron supplementation is a common recommendation for pregnant women to prevent iron deficiency during pregnancy. There is an increasing concern about excessive iron consumption as a general iron prophylaxis by pregnant women without any due consideration about their dietary iron intake or iron status. Our present study investigated the association between total iron intake from diet and supplements and fetal growth in 337 pregnant women at mid-pregnancy in South Korea.MethodsIron intake from diet and supplements was examined by a 24-hour recall method. Subjects were divided into three groups based on tertiles of total iron intake levels. Fetal biometry was assessed by ultrasonography at mid-pregnancy.ResultsAbout 99% of the non-supplement users had iron intake below the recommended nutrient intake (RNI) for pregnant women (24xa0mg), whereas 64.9% of supplement users had iron intake above the upper level (UL) (45xa0mg). In the babies of mothers in the third tertile of iron intake (>17.04xa0mg), biparietal diameter, abdominal circumference, and femur length were lower by 0.41xa0cm (P =0.019), 0.41xa0cm (Pu2009=u20090.027), and 0.07xa0cm (Pu2009=u20090.051), respectively, than the babies of mothers in the second tertile of iron intake (11.49u2009~u200917.04xa0mg).ConclusionThese results suggest that excessive maternal iron intake at mid-pregnancy is associated with reduced fetal growth. Iron supplementation for pregnant women should be individualized according to their iron status. Appropriate diet education is needed for pregnant women so that they can consume adequate amounts of iron from food and supplements.

Fruit and vegetable intake influences the association between exposure to polycyclic aromatic hydrocarbons and a marker of oxidative stress in pregnant women.

Background/Objectives:Exposure to polycyclic aromatic hydrocarbons (PAHs) during pregnancy is known to increase oxidative stress, which may influence pregnancy outcomes and health of the child.Subjects/Methods:This study investigated whether fruit and vegetable intake modifies the relationship between exposure to PAHs and oxidative stress status during pregnancy. Urinary levels of 2-naphthol and 1-hydroxypyrene (biomarkers of exposure to PAHs), and malondialdehyde (MDA; a biomarker of oxidative stress) were analyzed in 715 pregnant women at 12–28 weeks of gestation. The dietary antioxidant intake during pregnancy was estimated using the 24-h recall method. Urinary 2-naphthol, 1-hydroxypyrene and MDA levels were analyzed by high-performance liquid chromatography–fluorescence detection.Results:The urinary MDA level was positively correlated with the 2-naphthol level (r=0.255, P<0.001) and 1-hydroxypyrene level (r=0.240, P<0.001). Multiple regression analysis after adjustment for covariates revealed that the urinary 1-hydroxypyrene level was positively associated with the MDA level; these positive associations only existed in pregnant women, with either the fruit and vegetable intake or the vitamin C intake in the first tertile (<390.1u2009g/day) or in the first and second tertiles (<141.5u2009mg/day), respectively.Conclusions:These results suggest that an adequate maternal intake of fruit, vegetables and vitamin C is beneficial to the defense against the oxidative stress associated with exposure to PAHs in pregnant women.

Blood Cadmium Concentrations of Male Cigarette Smokers Are Inversely Associated with Fruit Consumption

Decreased fruit and vegetable consumption, along with elevated blood cadmium concentrations, are frequently observed among cigarette smokers. Few studies have investigated whether the blood cadmium concentrations of cigarette smokers are associated with the consumption of antioxidative nutrients, as well as foods containing high concentrations of antioxidative nutrients and phytochemicals, such as fruits and vegetables. In this study, we aimed to determine where there is any relationship between blood cadmium concentration and the consumption of certain foods and nutrients in adult male smokers. Blood cadmium concentrations in whole blood samples from 546 adult men, whose pregnant wives were registered in the Mothers and Childrens Environmental Health Study, were analyzed using the graphite furnace atomic absorption spectrophotometry method. Dietary intakes were assessed using a semiquantitative FFQ. Blood cadmium concentrations were higher in the smokers than in the nonsmokers (P < 0.001). Multiple regression analysis with covariates revealed that blood cadmium concentrations were negatively associated with intakes of fruit (P = 0.001), vitamin C (P = 0.035), and fiber (P = 0.049), but only in the smokers. These results warrant future studies to explore any mechanisms responsible for fruits beneficial role against elevated blood cadmium concentrations in smokers.

Relationship between body-mass index and serum folate concentrations in pregnant women.

The concentration of micronutrients impacts fetal development and pregnancy outcome and has been suggested to be negatively correlated with the body-mass index (BMI). We evaluated the relationship between BMI and the serum folate concentration in 802 and 660 Korean pregnant women in mid- and late pregnancy, respectively, who participated in a multicenter prospective study. There was a significant negative correlation between BMI value and the serum folate concentration at mid- and late pregnancy (P for trend 0.001 and 0.024, respectively). A general linear model confirmed this correlation at both time points after adjusting for gestational age and total folate intake. These findings are important as the serum folate concentration is a rate-limiting factor for placental folate transport to the fetus, and an inadequate folate supply may cause various malformations.

Development and evaluation of a food frequency questionnaire for Vietnamese female immigrants in Korea: the Korean Genome and Epidemiology Study (KoGES)

The objectives of this study were to develop a food-frequency questionnaire (FFQ) for Vietnamese female immigrants in Korea and to evaluate the validity of the FFQ. A total of 80 food items were selected in developing the FFQ according to consumption frequency, the contribution of energy and other nutrients, and the cooking methods based on one-day 24 hour recall (24HR) from 918 Vietnamese female immigrants between November 2006 and November 2007. The FFQ was validated by comparison with 24HR of 425 Vietnamese female immigrants between November 2008 and August 2009. The absolute nutrient intake calculated from the FFQ was higher than that estimated by 24HR for most nutrients. The correlation coefficients between 24HR and FFQ ranged from 0.10 (vitamin C) - 0.36 (energy) for crude intake, 0.05 (vitamin E) - 0.32 (calcium) for per 1000 kcal, and 0.08 (zinc) - 0.34 (calcium) for energy-adjusted, respectively. More than 70% of subjects were classified into the same or adjacent agreement groups for nutrients other than fiber, sodium, vitamin A, vitamin C, and vitamin E, while less than 10% of subjects were classified into complete disagreement groups. We conclude that the FFQ appears to be an acceptable tool for estimating nutrient intake and dietary patterns of Vietnamese female immigrants in Korea. Future studies to validate the FFQ using various biomarkers or other dietary assessment methods are needed.

SNP276G>T polymorphism in the adiponectin gene is associated with metabolic syndrome in patients with type II diabetes mellitus in Korea.

Few studies have examined an association between SNP276 and the risk of metabolic syndrome (MetS), which accelerates the development of diabetic complications, in patients with type II diabetes mellitus (T2DM). This study examined whether the SNP276G>T polymorphism is associated with risk of MetS in 673 Korean patients with T2DM from an ongoing prospective study. Multiple logistic regression analysis revealed that the OR for MetS was greater in patients with the TT genotype than in those with the GG genotype (OR=2.071; 95% CI=1.088–3.943) after adjustment of the putative risk factors for MetS. After examining the relationship between serum adiponectin and MetS risk for each genotype, only in patients with the GT genotype, serum adiponectin was negatively associated with the risk of MetS (OR=0.287; 95% CI=0.193–0.427). The SNP276G>T polymorphism may have an independent role in the determination of MetS in Korean patients with T2DM.

Relation between serum folate status and blood mercury concentrations in pregnant women

OBJECTIVEnTo evaluate the relation between maternal serum folate status and blood mercury in pregnant Korean women.nnnMETHODSnThe nutritional status of folate and the blood mercury concentration were measured in pregnant Korean women who participated in a multicenter prospective study from 2006 through 2011. We analyzed existing blood mercury data based on serum folate status at two gestational time points (mid and late pregnancy, nxa0=xa01105 and 841, respectively).nnnRESULTSnSerum folate concentrations in pregnant women were negatively associated with blood mercury concentrations at mid and late pregnancy (P trendxa0=xa00.012 and 0.002, respectively). A general linear model developed after adjusting for covariates indicated a significant negative association between the two at mid and late pregnancy.nnnCONCLUSIONnWe found a negative association between serum folate and blood mercury concentrations in pregnant Korean women.

Carbohydrate Intake Interacts With SNP276G>T Polymorphism in the Adiponectin Gene to Affect Fasting Blood Glucose, HbA1C, and HDL Cholesterol in Korean Patients With Type 2 Diabetes

Background/Objective: The SNP276G>T polymorphism in the adiponectin gene has been reported to be associated with type 2 diabetes and impaired glucose tolerance. The objective of this study was to examine whether SNP276G>T polymorphism influences the blood glucose levels in relation to dietary carbohydrate intake. Subjects/Methods: In an ongoing, prospective study, 673 patients with type 2 diabetes (339 men and 334 women, aged 40–85 years) were recruited from one of two diabetes clinics in Seoul, Korea. The levels of carbohydrate intake were categorized as <55%, 55%–65%, and >65% of total energy intake. Results: Significant gene–nutrient interactions between SNP276G>T polymorphism and the level of carbohydrate intake were found, which modulated plasma fasting blood glucose ( p = 0.0277), HbA1C ( p = 0.0407), and high-density lipoprotein (HDL) cholesterol ( p = 0.0134) concentrations. The G allele was associated with higher fasting blood glucose only in subjects consuming a low-carbohydrate diet (<55% of energy). However, when carbohydrate intake was intermediate (55%–65%), carriers of the T allele had greater fasting blood glucose and HbA1C concentrations. When carbohydrate intake was high (>65%), carriers of the T allele had greater HDL cholesterol concentrations. This interaction was significant even when carbohydrate intake was considered a continuous variable ( p = 0.0200 for fasting blood glucose, p = 0.0408 for HbA1C, and p = 0.0254 for HDL cholesterol), suggesting a strong dose–response relation. Conclusions: Our data show that the effect of the SNP276G>T polymorphism on plasma fasting blood glucose, HbA1C, and HDL cholesterol concentrations depends on dietary carbohydrate intake.

Vegetables, but Not Pickled Vegetables, Are Negatively Associated With the Risk of Breast Cancer

This study investigated the association between pickled vegetable consumption and the risk of breast cancer using a validated food frequency questionnaire. A total of 358 patients with breast cancer who were matched to 360 healthy controls by age (using a 5-yr age distribution) were recruited from the National Cancer Center in South Korea. After adjusting for nondietary risk factors, total vegetable intake was inversely associated with risk of breast cancer. However, unlike nonpickled vegetables, pickled vegetable intake and its proportion relative to total vegetables were positively associated with the risk of breast cancer, and this association was more profound and consistent when pickled vegetable intake was considered as a proportion relative to total vegetables (odds ratio [OR] = 6.24, 95% confidence interval [CI] = 3.55–10.97; P for trend <0.001 for highest vs. lowest quartiles of intake) than as the absolute consumed amount (OR = 2.47, 95% CI = 1.45–4.21; P for trend = 0.015 for highest vs. lowest quartiles of intake). These results suggest that not only the amount of total vegetable intake but also the amounts of different types of vegetable (i.e., pickled or nonpickled) and their proportions relative to total vegetables are significantly associated with the risk of breast cancer.