RBP-to-retinol ratio, but not total RBP, is elevated in patients with type 2 diabetes.

AIM: It was recently reported that serum retinol-binding protein (RBP), also known as retinol-binding protein 4 (RBP4), was positively associated with systemic insulin resistance. We hypothesized that an imbalance between RBP and retinol might be the underlying cause for this association. METHODS: We studied the ratio between RBP and retinol in 233 humans divided into groups depending on normal glucose tolerance (NGT), impaired glucose tolerance (IGT), type 2 diabetes (T2DM) and presence or absence of obesity. RESULTS: Plasma RBP and retinol levels were lower in patients with T2DM than in individuals with NGT (p < 0.05 and p < 0.0001 respectively). In contrast, RBP-to-retinol ratio was higher in individuals with T2DM (p < 0.0001) and IGT (p < 0.05). Following multivariate adjustment, RBP and retinol correlated positively with low-density lipoprotein (LDL) and triglycerides (p < 0.0001, except retinol and LDL: p < 0.001). RBP-to-retinol ratio correlated positively with glucose 2 h after an oral glucose tolerance test (p < 0.0001) and with C-reactive protein (p < 0.001). Retinol, RBP and adipose tissue RBP messenger RNA (mRNA) levels shared an inverse relationship with plasma interleukin-6, and adipose tissue RBP mRNA levels correlated positively with plasma tumour necrosis factor-alpha (TNF-alpha) and skeletal muscle TNF-alpha mRNA levels. CONCLUSIONS: Our results suggest that the excess of RBP relative to retinol, assessed as the RBP-to-retinol ratio, is more indicative of T2DM than RBP itself. Hence, the previously reported insulin resistance in mice induced by overexpression or injection of RBP could be because of higher levels of RBP relative to retinol rather than higher total levels of RBP. Moreover, TNF-alpha may have a role in RBP-mediated adipose to muscle crosstalk.

Zinc and multivitamin supplementation have contrasting effects on infant iron status: a randomized, double-blind, placebo-controlled clinical trial.

BACKGROUND/OBJECTIVES: Zinc (Zn) supplementation adversely affects iron status in animal and adult human studies, but few trials have included young infants. The objective of this study was to determine the effects of Zn and multivitamin (MV) supplementation on infant hematologic and iron status. SUBJECTS/METHODS: In a double-blind RCT, Tanzanian infants were randomized to daily, oral Zn, MV, Zn and MV or placebo treatment arms at the age of 6 weeks of life. Hemoglobin concentration (Hb) and red blood cell indices were measured at baseline and at 6, 12 and 18 months of age. Plasma samples from 589 infants were examined for iron deficiency (ID) at 6 months. RESULTS: In logistic regression models, Zn treatment was associated with greater odds of ID (odds ratio (OR) 1.8 (95% confidence interval (CI) 1.0-3.3)) and MV treatment was associated with lower odds (OR 0.49 (95% CI 0.3-0.9)). In Cox models, MV was associated with a 28% reduction in risk of severe anemia (hazard ratio (HR)=0.72 (95% CI 0.56-0.94)) and a 26% reduction in the risk of severe microcytic anemia (HR=0.74 (0.56-0.96)) through 18 months. No effects of Zn on risk of anemia were seen. Infants treated with MV alone had higher mean Hb (9.9 g/dl (95% CI 9.7-10.1)) than those given placebo (9.6 g/dl (9.4-9.8)) or Zn alone (9.6 g/dl (9.4-9.7)). CONCLUSIONS: MV treatment improved iron status in infancy, whereas Zn worsened iron status but without an associated increase in risk for anemia. Infants in long-term Zn supplementation programs at risk for ID may benefit from screening and/or the addition of a MV supplement.

Validation and comparison of two computerized methods of obtaining a diet history.

The aim of this study was to validate two computerized methods of obtaining a diet history (DH and EBIS). The food consumption of 12 men and eight women was calculated by weighing each food item over a period of 8 days. Thereafter the diet history was taken over this period by using both programs alternatively. The intake of energy, protein, fat and carbohydrates, and 10 further nutrients was evaluated and the percentage difference calculated. In general, the intake of nutrients calculated from the diet history tended to be underestimated by most of the people interviewed. The mean daily intake of the nutrients calculated from the DH program deviates from -34% to +20% (mean SD = 48.1) and -35% to +15% for EBIS (mean SD = 28.1). In conclusion, both computerized methods proved useful for epidemiological studies, but not for the determination of deficiencies in individuals.

Organochlorine pesticide residues in human milk of a Hmong hill tribe living in Northern Thailand.

In December 1998 whole breast milk samples from 25 Hmong mothers living in the village of Mae Sa Mai, 40 km north of Chiang Mai City, Northern Thailand, were collected and analysed for DDT, heptachlor, HCB and HCH residues (fat normalized data). Short questionnaires and anthropometric measurements were used to obtain information on personal characteristics, lifestyle, contact with pesticides, dietary habits and former residences. DDT was detected in all samples with a median and maximum level of 209 and 2012 ng of total DDT isomers per millilitre of milk, respectively. The median and highest percentages of p,p'-DDT were 23.2 and 44.7%. In 15 samples heptachlor was detected in the metabolized form of heptachlor-epoxide with a median value of 4.4 ng/ml. The estimated daily intakes of DDT, heptachlor and heptachlor-epoxide by the infants exceeded up to 20 times the acceptable daily intakes as recommended by the FAO and WHO. In nine samples HCB was detected with a median value of 5.4 ng/ml from which seven of the nine also had the highest values of DDT residues. The gamma-isomer of HCH was only found in one sample with 3.6 ng/ml. The mean sum-DDT residues with 14.96 mg/kg milk fat, as well as the estimated daily intakes by the infants are one of the highest reported in the 1990s. The fact that the mother breast-feeds her first child and that she originally comes from a region where DDT is still in use as a vector control agent, as well as the former use of organochlorine pesticides (OCPs) in agriculture, seem to be the main factors for high DDT and other OCP residues in the mothers' milk.

Determination of retinol, antioxidant vitamins and homocysteine in skin puncture blood.

For determination of the vitamin status via mass screening, simple and rapid methods are required. Additionally, blood samples should be obtained using simple and low invasive sampling techniques. To fulfill this existing methods have been modified to analyze retinol, tocopherols, beta-carotene, vitamin C and homocysteine in 20 microliters plasma. Blood samples were obtained via skin punctures. HPLC measurements were carried out with isocratic separation and precolumn derivatization. Intra and interday variation coefficients were below 8% and regression coefficients better than 0.99 for all measurements. The difference between venous and capillary samples were < 5%. In conclusion, the methods employed proved satisfactory for the determination of important nutritional parameters in blood samples obtained via skin punctures. These methods are therefore well suited for mass screening, especially under field conditions in developing countries.

A diet rich in fat and poor in dietary fiber increases the in vitro formation of reactive oxygen species in human feces.

Production of reactive oxygen species in the lumen of the colon, a process that is influenced by nutritional factors, may be important in the etiology of colorectal cancer. Because research on humans in support of this hypothesis is lacking, the objective of this study was to measure the effect of different dietary compositions on the in vitro oxygen radical production in human feces. Over a period of 12 d, seven healthy subjects received a diet rich in fat (50%) and meat and poor in dietary fiber. After a period of 1 wk, they received a vegetarian diet poor in fat (20%) and rich in dietary fiber. At the end of each study period, feces were collected and analyzed for in vitro oxygen radical production with dimethylsulfoxide as the free radical scavenger. The mean hydroxyl radical production was 13 times greater in feces of subjects when they consumed the diet rich in fat and poor in dietary fiber [52.7 +/- 29.5 micromol/(g feces x h)] than when they consumed the diet poor in fat and rich in dietary fiber [3.9 +/- 3.9 micromol/(g feces x h); P < 0.05]. This difference was associated with a 42% higher fecal iron concentration when they consumed the first diet (7.0 +/- 19.2 micromol/g feces) than when they consumed the second (4.9 +/- 1.9 micromol/g feces; P < 0.05). The results of this study confirm that diets high in fat and meat and low in fiber markedly increase the potential for hydroxyl radical formation in the feces, which in turn may contribute to an enhanced risk of colorectal cancer.

Effect of the type of beverage and meat consumed by alcoholics with alcoholic liver disease.

We analyzed meat products and alcoholic beverage preference in patients with the three stages of alcoholic liver disease (ALD) compared with controls using diet history data. Daily consumption of total alcohol, types of alcoholic beverages, and types of meat and meat products in grams was obtained by dietary history taken from patients with biopsy proven stage of ALD. A strong association was found between the ALD subjects and total alcohol and beer consumption. There was a significant increase in the consumption of total pig products, pork, and offal in the ALD groups compared with controls. There was a significant positive correlation between beer consumption and pork in alcoholic hepatitis, total pork products in alcoholic hepatitis, and cirrhosis and offal in alcoholic hepatitis and cirrhosis. There was no correlation with the fatty liver stage of ALD. The strongest correlation was between beer and total pig products in the alcoholic hepatitis group. Wine consumption was negatively correlated with the consumption of pig products and beer in the alcoholic cirrhosis group. In conclusion, the association of total pig product consumption with cirrhosis mortality in various countries was validated by personal diet history data obtained from ALD patients in a tested clinical microcosm. The results suggest that this association may be modified by the type of alcoholic beverage that is preferentially consumed.

Dietary intake and nutritional status of women and pre-school children in the Republic of the Maldives.

OBJECTIVE: Malnutrition and poor nutritional status among children are common problems in the Republic of Maldives, a small island nation in the Indian Ocean. The aim of this study was to determine possible macro- and micronutrient deficiencies in the traditional Maldivian diet. DESIGN: In five atolls, 333 women with children aged between 1 and 4 years who were no longer breast-fed were interviewed, using a 24-hour recall. Additionally, the weights and heights of both the women and children were measured, and blood samples from 15 women were collected for measurements of vitamins A and E, beta-carotene, homocysteine, cholesterol and haemoglobin. RESULTS: Of the women, 22% had a body mass index (BMI) below 18.5. Of the children, 41% were stunted, 14% were wasted and 51% were underweight. The women's and children's diets were sufficient in protein (14%) and carbohydrates (67%) but deficient in fat, which contributed only 19% to the total energy intake. Consumption of dietary substances that depend on vegetable and fruit intake (e.g. beta-carotene, vitamin C, dietary fibre and folic acid) was low. The low intake of beta-carotene was underlined by low plasma concentration. The estimated iron intake was low, although blood haemoglobin levels were normal. CONCLUSIONS: Marginal nutritional status and marginal malnutrition are due to low fat intake and selected micronutrient deficiency. Higher intakes of locally available vegetables and fruits and fat (especially for children) on a regular basis might reverse the deficits documented on the atolls.