Effect of lycopene supplementation on insulin-like growth factor-1 and insulin-like growth factor binding protein-3: a double-blind, placebo-controlled trial

OBJECTIVE: Studies have suggested a link between lycopene and insulin-like growth factor-1 (IGF-1). The aim of this study was to test the effect of lycopene supplementation on IGF-1 and binding protein-3 (IGFBP-3) status in healthy male volunteers. DESIGN, SETTING, SUBJECTS AND INTERVENTION: This was a 4 week randomized, double-blind, placebo-controlled study of lycopene supplementation (15 mg/day) in healthy male volunteers (n=20). Fasting blood samples were collected at baseline and after 4 weeks. Samples were analysed for lycopene by high-performance liquid chromatography (HPLC) and IGF-1 and IGFBP-3 by enzyme-linked immunosorbent assay (ELISA). Changes in end points from baseline were compared in those who received placebo versus those who received the lycopene supplement. RESULTS: Median change in lycopene from baseline (post-supplement - baseline) was higher in subjects in the intervention than those on placebo (lycopene group 0.29 (0.09, 0.46); placebo group 0.03 (-0.11, 0.08) micromol/l; median (25th, 75th percentiles), P<0.01). There was no difference in median change in IGF-1 concentrations (lycopene group -0.6 (-2.6, 1.9); placebo group -1.15 (-2.88, 0.95) nmol/l, P=0.52), or median change in IGFBP-3 concentrations (lycopene group 245 (-109, 484); placebo group 101 (-34, 234) nmol/l, P=0.55) between intervention and control groups. Change in lycopene concentration was associated with the change in IGFBP-3 in the intervention group (r=0.78; P=0.008; n=10). CONCLUSIONS: Lycopene supplementation in healthy male subjects has no effect on IGF-1 or IGFBP-3 concentrations in a healthy male population. However, the association between change in lycopene concentration and change in IGFBP-3 in the intervention group suggests a potential effect of lycopene supplementation on IGFBP-3.     

The role of insulin-like-growth-factor-binding protein 3 in the evaluation of disease activity in acromegaly

Studied the diagnostic value of measurements of insulin-like growth factor binding protein-3 compared to insulin-like growth factor-1 as a parameter of disease activity in patients with active (n = 12, 8 females, 4 males, 29-69 years old) and inactive (n = 14, 11 females, 3 males, 28-58 years old) acromegaly. Patients were assigned to the active group if they had GH levels > or = 2 ng/ml, to the inactive group if they had growth hormone levels < 2 ng/ml after 75 g glucose challenge. The absolute serum insulin-like growth factor-1 concentration (526 +/- 66 ng/ml vs. 272 +/- 61 ng/ml, p = 0.015; mean +/- SE) and the insulin-like growth factor-1 standard deviation score (3.23 +/- 0.33 vs. 0.67 +/- 0.58, p = 0.0013) was higher in the active than in the inactive group, but no significant difference was seen between the corresponding insulin-like growth factor binding protein-3 values (7270 +/- 1500 vs. 5340 +/- 1050 ng/ml). Positive significant correlation was found between insulin-like growth factor-1 and insulin-like growth factor binding protein-3 both in the active (n = 12, r = 0.55, p < 0.05) and in the inactive (n = 14, r = 0.61, p < 0.05) group. A significant negative correlation existed between insulin-like growth factor binding protein-3 and age in the inactive (r = 0.58, n = 14; p < 0.05), but not in the active (r = 0.35, n = 12) group. The diagnostic value of insulin-like growth factor binding protein-3 is less than that of the insulin-like growth factor-1. Conclude that the insulin-like growth factor binding protein-3 has smaller suitability to determine the activity of acromegaly than the insulin like-growth factor-1 measurement.     

多囊卵巢综合征子宫内膜胰岛素受体和胰岛素样生长因子-Ⅰ的表达与临床特征研究

目的:检测多囊卵巢综合征(PCOS)患者子宫内膜胰岛素受体(IR)、胰岛素样生长因子-Ⅰ(IGF-Ⅰ)的表达,研究其与PCOS患者性激素、血脂、胰岛素抵抗指数(HOMA)、体重指数(BM I)等临床特征的关系。方法:选取P-COS患者31例作为实验组,输卵管性不孕患者20例作为对照组。采用免疫组化方法检测子宫内膜IR、IGF-Ⅰ表达。用免疫法测定血清性激素、血脂、糖耐量葡萄糖试验(OGTT)、胰岛素释放试验(INS)。结果:实验组子宫内膜IR表达低于对照组,IGF-Ⅰ表达高于对照组。PCOS肥胖组IR低于非肥胖组,肥胖组IGF-Ⅰ表达高于非肥胖组;胰岛素抵抗组IGF-Ⅰ表达高于非胰岛素抵抗组。相关性分析发现IGF-Ⅰ表达与BM I、HOMA呈正相关。结论:PCOS患者子宫内膜IR表达低于正常妇女,但IGF-Ⅰ表达却增高。肥胖及胰岛素抵抗增加了IGF-Ⅰ在子宫内膜的表达。     

Soy isoflavones do not modulate circulating insulin-like growth factor concentrations in an older population in an intervention trial

Insulin-like growth factors (IGF) are essential for normal growth and maintenance of lean muscle mass; however, high insulin-like growth factor-I (IGF-I) and low IGF binding protein-3 (IGFBP-3) levels are also associated with several cancers. To test the hypothesis that long-term soy isoflavone supplementation decreases circulating IGF-I concentrations, we conducted a controlled, parallel-arm, double-blind intervention study with 150 participants (85% men), 50-80 y old. Participants were randomly assigned to consume a soy beverage powder daily for 12 mo. The active treatment group (+ISO) received soy protein containing 83 mg isoflavones, whereas the comparison group (-ISO) received soy protein containing 3 mg isoflavones. Serum IGF-I and IGFBP-3 were measured by ELISA. Mean change in serum IGF-I concentrations was similar in the two groups (+1.4 nmol/L in +ISO, +1.2 nmol/L in -ISO; P = 0.74, 95% confidence interval -1.1, +1.5 nmol/L for the 0.21 nmol/L difference between groups), indicating no effect of the isoflavone intervention. Similarly, the changes in IGFBP-3 and the IGF-I/IGFBP-3 ratio were similar in both groups, again showing no effect of +ISO treatment. A 12 mo, 83 mg/d soy isoflavone intervention did not modulate serum IGF in an older, mostly male population.     

司坦唑醇对促性腺激素释放激素拟似物处理后的青春期大鼠生长板软骨细胞IGF-1 mRNA表达及其蛋白合成、分泌的影响

目的研究司坦唑醇（stanozolol,ST）对促性腺激素释放激素拟似物（gonadotropin releasing hormone agonist,GnRHa）处理后的离体青春期大鼠生长板软骨细胞胰岛素样生长因子-1（insulin-like growth factor-1,IGF-1）mRNA表达及其蛋白合成、分泌的影响。方法将6只雌鼠的原代软骨细胞,分为时效组、量效组。根据是否用司坦唑醇干预,将时效组和量效组分为时效干预组,时效对照组;量效于预组,量效对照组,分别观察司坦唑醇的干预时限和剂量对促性腺激素释放激素拟似物处理后离体青春期大鼠生长板软骨细胞增殖的影响。采用软骨细胞增殖能力测定法（MTT）和免疫组化法检测不同剂量、不同时间点司坦唑醇处理的离体的青春期大鼠生长板软骨细胞的增殖细胞核抗原（proliferating cell nuclear antigen,PCNA）表达,荧光实时定量RT—PCR检测软骨细胞的IGF-1 mRNA表达。酶联免疫吸附法（enzyme—linked immunosorbent assay,ELISA）测定胰岛素样生长因子-1的合成。结果司坦唑醇以时效和量效作用方式,对雌激素受抑的离体青春期大鼠生长板软骨细胞增殖呈双相型影响。在合适的剂量和疗程时,软骨细胞增殖效应可达最好效果。①司坦唑醇作用2h后,软骨细胞IGF-1 mRNA表达显著增加,与时效对照组基础值相比,差异有显著意义（P〈0．05）,并存在较强的时间依赖性;作用8h时,达最高峰（为时效对照组基础值的3．8倍）。司坦唑醇的作用在（10^-10～10^-5）mol／L时,与软骨细胞的细胞核抗原增殖效应存在明显的剂量依赖性（组间比较,差异有显著意义,P〈0．05）;在10^-7mol／L时,软骨细胞的增殖细胞核抗原表达达最高峰（为基础值的5．75倍）。②司坦唑醇作用自5h起,软骨细胞胰岛素样生长因子-1蛋白合成与时间点为0组比较,差异有显著意义（P=0．042）;5h-20h时,作用存在显著时间依赖性（P〈0．05）;作用20h时,达峰值（为量效对照组基础值的3．3倍）。与量效对照组比较,司坦唑醇自10^-10mol／L组,胰岛素样生长因子-1蛋白含量开始增加,并在10^-7mol／L组达峰值（P=0．000）。结论司坦唑醇可以量效、时效的作用方式,影响和增加对促性腺激素释放激素拟似物处理后的体外培养雌激素水平,促进青春期大鼠生长板软骨细胞IGF-1 mRNA的表达和胰岛素样生长因子-1的合成、分泌,推测司坦唑醇促进生长效应机制与生长板局部胰岛素样生长因子-1的自分泌、旁分泌增加有关。     

Effect of a tomato drink intervention on insulin-like growth factor (IGF)-1 serum levels in healthy subjects

There is concern that dietary factors can modulate the insulin-like growth factor (IGF) system. The aim of this work was to evaluate the effect of a tomato drink intervention providing small amounts of lycopene and other carotenoids on serum levels of IGF-1. Twenty healthy young subjects participated in a repeated measure double-blind, cross-over design. Subjects consumed 250 ml of a tomato drink or a placebo drink for 26 days separated by 26 days wash-out. The tomato drink intake increased plasma lycopene, phytoene, phytofluene, and beta-carotene concentrations by 0.22, 0.12, 0.13, and 0.18 micromol/L, respectively (P < 0.05). No significant effect of the tomato drink intake on IGF-1 levels was observed. However, changes in lycopene before and after each experimental period were inversely and significantly correlated with those of IGF-1 (r = -0.33, P < 0.05, N = 20). No correlation was found with the other carotenoids. A significant reduction of IGF-1 serum level (-5.7%) was observed in subjects (n = 11) with the highest plasma lycopene response but also IGF-1 levels following the tomato drink intake (P < 0.05). No effect was evident after the placebo treatment. The results suggest that further exploration of the role of tomato lycopene on IGF-1 modulation both on healthy and on subjects at risk is necessary.     

Serum beta-carotene, lycopene and alpha-tocopherol levels of healthy people in northeast Thailand

Human serum contains many different antioxidants which may be important in the maintenance of antioxidant status. beta-carotene and lycopene are carotenoids with potent antioxidant activity. Carotenoids intake probably protects against cancers and may affect the risk of several chronic conditions. alpha-tocopherol is well known for its function as antioxidant and in reduction of heart disease and cancer risk. We aimed to establish baseline values for serum beta-carotene, lycopene and alpha-tocopherol concentrations in healthy northeast Thais. Fasting serum beta-carotene, lycopene and alpha-tocopherol levels from 294 subjects aged 23-75 years old in northeast Thailand were determined by high performance liquid chromatography (HPLC). The mean serum beta-carotene, lycopene and alpha-tocopherol levels were 0.53 +/- 0.32 micromol/L, 0.57 +/- 0.37 micromol/L, and 26.64 +/- 14.85 micromol/L respectively. Serum beta-carotene and lycopene levels in females (N = 118) were significantly higher than the value for males (N = 176), ie 0.60 +/- 0.31 micromol/L versus 0.48 +/- 0.32 micromol/L (p = 0.002) for beta-carotene and 0.74 +/- 0.38 micromol/L versus 0.46 +/- 0.33 micromol/L (p<0.001) for lycopene whereas alpha-tocopherol level in males (28.60 +/- 14.34 micromol/L) was significantly higher than in females (23.72 +/- 15.16 micromol/L) (p = 0.006). beta-carotene level was positively correlated with alpha-tocopherol (r = 0.22, p<0.001) and lycopene levels (r = 0.63, p<0.001). The results from this study give the baseline data of serum beta-carotene, lycopene and alpha-tocopherol levels in healthy northeast Thai population and also suggest future study on the relationship of dietary intake.     

Low pyridoxal 5'-phosphate is associated with increased risk of coronary artery disease

OBJECTIVE: The purpose of this study was to investigate the association between plasma pyridoxal 5'-phosphate (PLP) status and lipid profiles and to estimate the relation to the risk of coronary artery disease (CAD). METHODS: Patients who were identified by cardiac catheterization as having > or =70% stenosis of one major coronary artery were assigned to the case group (n = 184). The control group (n = 516) was comprised of healthy individuals with normal blood biochemical values. Plasma PLP, homocysteine, high-sensitivity C-reactive protein, lipid profiles (total cholesterol, low-density lipoprotein, high-density lipoprotein, very low-density lipoprotein, and triacylglycerol) were determined. RESULTS: Subjects with a plasma PLP level <30 nmol/L exhibited a significantly increased risk of CAD compared with subjects with a plasma PLP level > or =30 nmol/L (odds ratio, 1.85; 95% confidence interval, 1.16-2.95) after adjusting for homocysteine and high-sensitivity C-reactive protein. The association between PLP and the risk of CAD remained significant after each lipid profile was additionally adjusted. In addition, the combined presence of low PLP level and an abnormal lipid level increased the risk of CAD to an even greater degree. CONCLUSIONS: A borderline vitamin B6 deficiency (plasma PLP concentration <30 nmol/L) is strongly associated with the risk of CAD. The combined presence of low PLP and abnormal lipid levels increased the risk of CAD even further.     

Pharmacokinetics and tissue distribution of orally administered lycopene in male dogs

Consumption of lycopene, the predominant carotenoid in tomatoes and tomato products, is associated with reduced prostate cancer risk. The purpose of this study was to measure the pharmacokinetics and tissue distribution of lycopene after oral administration to male dogs. After single doses of 10, 30 and 50 mg/kg body weight (BW) lycopene to 2 dogs/dose, the mean half-life was 36 h and the plasma systemic exposure levels (AUC(0-)( infinity ), area under the curve) after the 30 and 50 mg/kg BW doses were similar. In a repeat dose study, 30 mg/(kg BW. d) administered orally to six dogs for 28 d resulted in steady-state plasma concentrations between 785 and 997 nmol/L lycopene. Apparent clearance, volume of distribution and apparent elimination half-life were 2.29 L/(h. kg), 96 L/kg and 30.5 h, respectively. Dogs were killed 1 or 5 d after the last dose and 23 tissues were collected for lycopene analysis. Lycopene concentrations were highest in liver, adrenals, spleen, lymph nodes and intestinal tissues. Liver lycopene concentrations were 66 and 91 nmol/g 1 and 5 d after cessation of treatment, respectively. Prostate lycopene concentrations were < 0.2 nmol/g both 1 and 5 d after dosing ceased (<0.4% of liver concentrations). Although 70% trans-lycopene was used in the dosing material, most of the lycopene identified in plasma and tissues was cis-lycopene.     

The levels of lycopene, alpha-tocopherol and a marker of oxidative stress in healthy northeast Thai elderly

An imbalance between oxidative stress and antioxidant capacity has been proposed to play an important role in the development and progression of chronic diseases in the elderly. The present study was carried out to investigate correlation between the serum antioxidants (lycopene and alpha-tocopherol) and malondialdehyde (MDA), a marker of oxidative stress in the healthy Thai elderly. The 207 healthy subjects aged 60-91 years old (72 males and 135 females) in Khon Kaen province, Thailand were enrolled in this study. They were interviewed by questionnaires about smoking habit. Serum lycopene and alpha-tocopherol levels were determined by high performance liquid chromatography (HPLC). MDA was measured by thiobarbituric assay. Serum lycopene and alpha-tocopherol levels in the elderly were 0.27 micromol/L (95% CI = 0.23-0.31) and 22.10 micromol/L (95% CI = 20.99-23.22), respectively. Males had significant lower serum lycopene and alpha-tocopherol levels than females (p<0.001). Of 72 males, 31.94% are current smokers whereas 1.4% of 135 females are current smokers. Current smokers had significantly lower serum lycopene (0.17 +/- 0.11 micromol/L) than current non-smokers (0.28 +/- 0.27 micromol/L) (p=0.0439) but level of alpha-tocopherol had non significance (p=0.210). Moreover, the current smokers had higher MDA malondialdehyde level (1.55 +/- 0.10 micromol/L) than the current non-smokers (1.35 +/- 0.04 micromol/L) (p=0.094). Thus, dietary antioxidant supplementation from local fruits and vegetables may have a beneficial role in the prevention of chronic diseases at high-risk oxidative stress such as smoking in these elderly.     

Methylenetetrahydrofolate reductase C677T polymorphism, folic acid and riboflavin are important determinants of genome stability in cultured human lymphocytes

We tested the hypothesis that methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism, folic acid deficiency and riboflavin deficiency, independently or interactively, are important determinants of genomic stability, cell death, cell proliferation and homocysteine (Hcy) concentration in 9-d human lymphocyte cultures. Lymphocytes of seven wild-type (CC) and seven mutant (TT) homozygotes were cultured under the four possible combinations of deficiency and sufficiency of riboflavin (0 and 500 nmol/L) and folic acid (20 and 100 nmol/L) at a constant L-methionine concentration of 50 micromol/L. Viable cell growth was 25% greater in TT than in CC cells (P<0.05) and 32% greater at 100 nmol/L folic acid than at 20 nmol/L folic acid (P=0.002). The comprehensive cytokinesis-block micronucleus assay was used to measure micronuclei (MNi; a marker for chromosome breakage and loss), nucleoplasmic bridges (NPB; a marker of chromosome rearrangement) and nuclear buds (NBUD, a marker of gene amplification). The MNi levels were 21% higher in TT cells than in CC cells (P<0.05) and 42% lower in the high folic acid medium than in the low folic acid medium (P<0.0001). The NBUD levels were 27% lower in TT cells than in CC cells (P<0.05) and 45% lower in the high folic acid medium than in the low folic acid medium (P<0.0001). High riboflavin concentration (500 nmol/L) increased NBUD levels by 25% (compared with 0 nmol/L riboflavin) in folate-deficient conditions (20 nmol/L folic acid medium; P<0.05), and there was an interaction between folic acid and riboflavin that affected NBUD levels (P=0.042). This preliminary investigation suggests that MTHFR C677T polymorphism and riboflavin affect genome instability; however, the effect is relatively small compared with that of folic acid.     

儿童血瘦素水平对青春期发育的作用

目的研究血瘦素水平对儿童青春期发育的作用.方法单纯性肥胖和健康学生各300名,调查男生首次遗精和女生月经初潮时间,测定血瘦素、性激素、生长激素和胰岛素水平.结果随年龄增长,瘦素在男生呈低→高→低变化,肥胖组(1.04±0.21)nmol/L→(1.20±0.27)nmol/L→(0.66±0.10)nmol/L,对照组(0.31±0.06)nmol/L→(0.45±0.10)nmol/L→(0.19±0.04)nmol/L;在女生呈增高趋势,肥胖组从(0.89±0.15)nmol/L增至(1.39±0.23)nmol/L,对照组从(0.46±0.08)nmol/L增至(0.88±0.18)nmol/L.各组性激素呈增高趋势.生长激素呈某一年龄突增,且男女不同(男生14～15岁,女生13～14岁).各年龄肥胖组瘦素和胰岛素高于对照组;男生各年龄肥胖组生长激素低于对照组.男女肥胖组血瘦素水平高于对照组,男(0.71±0.17)nmol/L与(0.30±0.04)nmol/L,女(1.11±0.21)nmol/L与(0.70±0.18)nmol/L;其初潮/首次遗精时间提前,男(12.5±1.2)岁与(13.2±1.2)岁,女(11.6±0.8)岁与(12.8±0.9)岁.女生瘦素水平高于男生,其初潮时间早于男生首次遗精时间.肥胖组男生的睾酮与瘦素呈负相关,女生的雌二醇与瘦素呈正相关,男生的生长激素与瘦素呈负相关,女生的生长激素与瘦素呈正相关;对照组女生的胰岛素与瘦素呈正相关.结论瘦素对青春期的启动可能有重要作用,对女性可能比男性更为重要;瘦素与生长激素相关关系的两性差异可能是造成男女生长突增时间不同的原因之一;瘦素与性激素相关关系的两性差异可能是造成男女首次遗精/初潮时间不同的原因之一.     

Effect of the methylenetetrahydrofolate reductase 677C-->T mutation on the relations among folate intake and plasma folate and homocysteine concentrations in a general population sample

BACKGROUND: Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in folate and homocysteine metabolism. The common MTHFR 677C-->T polymorphism decreases the enzyme's activity. OBJECTIVE: The objective of the study was to assess the effect of the polymorphism on the relations among folate intake, plasma folate concentration, and total plasma homocysteine (tHcy) concentration. DESIGN: The design was a cross-sectional analysis in a random sample (n = 2051) of a Dutch cohort (aged 20-65 y). RESULTS: At a low folate intake (166 micro g/d), folate concentrations differed significantly among the genotypes (7.1, 6.2, and 5.4 nmol/L for the CC, CT, and TT genotypes, respectively; P for all comparisons < 0.05). At a high folate intake (250 microg/d), folate concentrations in CT and CC subjects did not differ significantly (8.3 and 8.6 nmol/L, respectively, but were significantly higher (P = 0.2) than those in TT subjects (7.3 nmol/L; P = 0.04). At a low folate concentration (4.6 nmol/L), TT subjects had a significantly higher (P = 0.0001) tHcy concentration than did CC and CT subjects (20.3 compared with 15.0 and 14.1 micromol/L, respectively), whereas at a high folate concentration (11.9 nmol/L), the tHcy concentration did not differ significantly between genotypes (P > 0.2; <13.1 for all genotypes). The relation between folate intake and tHcy concentration had a pattern similar to that of the relation between plasma folate and tHcy concentrations. CONCLUSIONS: At any folate intake level, TT subjects have lower plasma folate concentrations than do CT and CC subjects. Yet, at high plasma folate concentrations, tHcy concentrations in TT subjects are as low as those in CT and CC subjects.     

Airway and circulating levels of carotenoids in asthma and healthy controls

BACKGROUND: Elevated oxidative stress and impaired antioxidant defences are increasingly recognised features of asthma. Carotenoids are potent dietary antioxidants that may protect against asthma by reducing oxidative damage. OBJECTIVES: This study aimed firstly, to characterise circulating and airway levels of carotenoids in asthma compared to healthy controls, in relation to dietary intake. Secondly, the study aimed to test whether airway lycopene defences can be improved using oral supplements. METHODS: Induced sputum and peripheral blood samples were collected from subjects with asthma (n = 15) and healthy controls (n = 16). Dietary carotenoid intakes were estimated using the 24-hour recall method and analysed using a modified version of the Foodworks 210 Nutrient Calculation Software. Another group of healthy controls (n = 9) were supplemented with 20 mg/day lycopene for 4 weeks. Carotenoids (beta-carotene, lycopene, alpha-carotene, beta-cryptoxanthin, lutein/zeaxanthin) were measured by HPLC. RESULTS: Despite similar dietary intake, whole blood levels of total carotenoids, lycopene, lutein, beta-cryptoxanthin, alpha-carotene and beta-carotene were significantly lower in asthma than controls. However, there were no differences in plasma or sputum carotenoid levels. Induced sputum carotenoid levels were significantly lower than plasma and whole blood levels, but correlated strongly with plasma levels (r = 0.798, p < 0.001). Although there were no overall increases in either plasma or sputum lycopene levels following supplementation, changes in airway lycopene levels correlated with changes in plasma levels (r = 0.908, p < 0.002). CONCLUSIONS: Whole blood, but not plasma or sputum, carotenoid levels are deficient in asthma. Plasma carotenoid levels reflect airway carotenoid levels and when plasma levels are improved using oral supplements this is reflected in the airways.     

低水平铅暴露儿童的GH/IGF-1轴变化及其与ALAD基因多态性的关系

目的:探讨低水平铅暴露儿童的生长激素/胰岛素样生长因子-1(GH/IGF-1)轴的变化及其与δ-氨基-γ-酮戊酸脱氢酶(ALAD)基因多态性的关系。方法:用钨舟原子吸收光谱法测定来自深圳市区242例学龄前儿童静脉血铅水平(BLL)。按血铅水平将患儿分为两组,A组BLL<50μg/L,B组BLL≥50μg/L。对两组对象的身高(H)、血红蛋白水平(Hb)、ALAD基因、生长激素(GH)、胰岛素样生长因子-1(IGF-1)和胰岛素样生长因子结合蛋白-3(IGFBP-3)水平进行比较。身高测量和血红蛋白检测用常规方法进行;ALAD基因多态性检测采用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)法;生长激素测定采用化学发光法;IGF-1和IGFBP-3测定采用ELISA法。结果:242例儿童的血铅水平范围为8～146μg/L,几何均数47μg/L。BLL≥50μg/L者占43%,≥100μg/L者占0.8%。两组儿童的IGFBP-3水平差异有统计学意义,B组明显低于A组。身高和IGF-1略有差异,但无统计学意义。基因多态性分析显示,223例为ALAD1-1型,19例为ALAD1-2型,未发现ALAD2-2型。ALAD2基因出现的频率为7.85%。两组儿童突变基因的频率分布差异无统计学意义。结论:本研究发现即使低水平铅暴露也与儿童血IGFBP-3水平明显降低有关,表明铅中毒损害儿童GH/IGF-1轴功能。在低水平铅暴露状态下,ALAD基因的多态性对儿童血铅水平并无明显影响。可能只有在高水平铅暴露时,ALAD基因变异才会对儿童铅中毒易感性发挥作用。     

Differences in body fat distribution and antioxidant status in Korean men with cardiovascular disease with or without diabetes

BACKGROUND: Abnormal body fat distribution and reduced antioxidant status have been shown to be effective markers of risk of cardiovascular disease (CVD). OBJECTIVE: The objective of this study was to determine the differences in body fat distribution and antioxidant status in healthy men (control subjects) and in men with CVD with or without diabetes. DESIGN: An oral-glucose-tolerance test was performed and CVD patients were subdivided into groups according to the presence or absence of diabetes. Adipose tissue areas were calculated from computed tomography scans made at the L1 and L4 vertebrae. Fasting serum concentrations of lipids, testosterone, insulin-like growth factor I, antioxidants, and plasma homocysteine were determined. RESULTS: There were no significant differences in mean age, body mass index (in kg/m(2)), or blood pressure between the groups. The visceral fat area at the L1 vertebra was nonsignificantly greater in CVD patients without diabetes than in control subjects, whereas it was significantly greater in CVD patients with diabetes than in control subjects at both the L1 and L4 vertebrae. Both groups of CVD patients had higher plasma concentrations of homocysteine and lower serum insulin-like growth factor I concentrations and superoxide dismutase activities than did control subjects. Serum ss-carotene and lycopene concentrations were lowest in the CVD patients with diabetes. CONCLUSION: The concurrent presence of CVD and diabetes is associated with a greater negative effect on the risk factors typically associated with significant declines in health status.     

Risk factors for vitamin D deficiency in breast-fed newborns and their mothers

OBJECTIVES: Vitamin D plays a critically important role in the development, growth, and mineralization of the skeleton during its formative years, and performs an equally essential role in maintaining a healthy mineralized skeleton for adults of all ages. We evaluated the vitamin D status and risk factors for vitamin D deficiency in healthy breast-fed newborns and their nursing mothers. METHODS: Serum 25-hydroxyvitamin D (25OHD), calcium, phosphorus, and alkaline phosphatase levels were measured in 54 newborns and their nursing mothers whose ages ranged from 18 to 38 y. The relation between serum 25OHD level and demographic factors was analyzed. Bone mineral density was measured in the mothers with a serum 25OHD level below 25 nmol/L to determine the extent of bone mineralization. RESULTS: The mean serum 25OHD level in the 54 mothers was 29.11 +/- 10.47 nmol/L. Forty-six percent of the mothers had serum 25OHD levels below 25 nmol/L. The risk factors for low maternal serum 25OHD level were found in decreasing order of importance as follows: low socioeconomic class (odds ratio [OR] = 8.1, P = 0.000), being covered (OR = 4.3, P = 0.023), and low educational level (OR = 3.5, P = 0.033). The mean serum 25OHD level in the newborns was 18.62 +/- 8.00 nmol/L. Eighty percent of the newborns had serum 25OHD levels below 25 nmol/L. There was a significant correlation between the serum 25OHD levels of the newborns and their mothers (r = 0.63, P = 0.01). The most important risk factor for low serum 25OHD level in the newborn was a maternal 25OHD level below 25 nmol/L (OR = 15.2, P = 0.002), followed a covered mother (OR = 6.8, P = 0.011). Bone mineral densitometry showed osteopenia in 40% of the women with serum 25OHD levels below 25 nmol/L. All women were from a lower socioeconomic class and 80% were covered. CONCLUSIONS: Vitamin D deficiency is still a common and serious health problem of women of reproductive age and their babies in developing countries at the outset of a new millennium.     

Associations among sex hormone binding globulin concentrations and characteristics of the metabolic syndrome in obese women

The aim of this study was to determine sex hormone binding globulin (SHBG) concentrations in premenopausal obese women who were otherwise healthy, and to evaluate the relationships between SHBG concentrations and features of the metabolic syndrome; 307 premenopausal women (mean age 30.9+/-10.2 years) were studied. Subjects were divided into two groups according to the BMI: Group I, women with BMI <30 kg/m2 (n=69) and Group II, women with BMI > or = 30 kg/m2 (n=238). Insulin resistance was determined according to the Homeostasis Model Assessment (HOMA) formula. Median SHBG concentration of Group I was 75.9 nmol/l. Group II was divided into two subgroups according to the median SHBG concentration of Group I; women with high SHBG (SHBG concentration > or = median level of the control group, i.e. > or = 76 nmol/l) and women with low SHBG (i.e. <76 nmol/l). The low SHBG group was significantly younger, with higher waist-to-hip ratio (WHR). Triglycerides, uric acid, insulin and HOMA values were significantly higher and HDL-cholesterol was significantly lower in the low SHBG group. Multiple regression analysis revealed that age and uric acid concentrations were significant independent predictors of SHBG concentrations in the whole group (regression summary, adjusted r2=0.1414, F=10.5627, p<0.001). It is concluded that low SHBG concentrations may indicate a severe degree of insulin resistance in premenopausal obese women.     

Vitamin D deficiency: a concern in premenopausal Bangladeshi women of two socio-economic groups in rural and urban region

OBJECTIVE: The study was designed to evaluate the vitamin D status in women of different physiological status of two socio-economic groups in Bangladesh. DESIGN: A cross-sectional study, using serum 25-hydroxyvitamin D (25-OHD), calcium, phosphorus and alkaline phosphatase activity. SETTING: Two regions of Bangladesh. The Dhaka city area and west region of Nandail (Betagair Union), Mymensingh. SUBJECTS: Representative subjects of two groups (low socio-economic group=group L, n=99; and high socio-economic group=group H, n=90) of Bangladeshi women aged 16-40 y. About 87% of the subjects were housewives and the rest, 13%, were distributed among other different professions. Each group comprised of three sub-groups (non-pregnant non-lactating=1, pregnant=2, and lactating=3). RESULTS: The influence of socio-economic status and physiological status on serum 25-OHD concentration (P=0.038, P=0.015, respectively), serum calcium concentration (P<0.001, P<0.001, respectively) and alkaline phosphatase activity (P<0.001, P<0.001, respectively) were observed. The distribution of serum 25-OHD concentration in both groups was shifted overall toward the lower limit of the normal range. Seventeen percent of women in group L and 12% of women in group H had serum 25-OHD concentration <25 nmol/l. Hypovitaminosis D (serum 25-OHD concentration < or = 37.5 nmol/l) was observed in 50% of subjects in group L and 38% of subjects in group H, respectively. The prevalence of hypovitaminosis was higher in lactating subjects of the groups L and H (63 and 46%, respectively) than in the other sub-groups in the same group. CONCLUSIONS: The results of the study suggested that women in Bangladesh were at risk of hypovitaminosis D and lactation was an additional risk factor in low income groups. The situation may increase the risk of bone loss.     

Vitamin D status affects serum parathyroid hormone concentrations during winter in female adolescents: associations with forearm bone mineral density

BACKGROUND: Vitamin D deficiency leads to secondary hyperparathyroidism, which has a negative effect on bone metabolism in the elderly. Puberty is an important time of bone metabolism and growth. The effect of serum 25-hydroxyvitamin D [25(OH)D] concentrations on parathyroid hormone concentrations and bone mineral density (BMD) has not been well studied cross-sectionally in adolescents. OBJECTIVE: We studied the effect of vitamin D status on serum intact parathyroid hormone (iPTH) concentrations and bone metabolism in adolescents. DESIGN: One hundred seventy-eight healthy female adolescents (aged 14-16 y) volunteered for this study, which was conducted in Finland (Helsinki, 60 degrees N) during the winter. Forearm BMD at radial and ulnar sites was measured by dual energy X-ray absorptiometry. The determinants of different variables were studied by use of regression models. RESULTS: On the basis of the relation between serum 25(OH)D and iPTH concentrations, serum 25(OH)D concentrations > approximately 40 nmol/L were needed to keep serum iPTH concentrations low. One hundred ten subjects (61.8%) had serum 25(OH)D concentrations < or =40 nmol/L. Twenty-four subjects (13.5%) were considered vitamin D deficient when the serum 25(OH)D concentration of 25 nmol/L was used as a cutoff. Subjects with serum 25(OH)D concentrations < or =40 nmol/L had low mean forearm BMD values at both the radial (P = 0.04) and ulnar (P = 0.08) sites. CONCLUSION: A large percentage of adolescent females have low vitamin D status during the winter in Finland, which seems to have negative effects on bone health.