The influence of inflammation on plasma zinc concentration in apparently healthy, HIV+ Kenyan adults and zinc responses after a multi-micronutrient supplement.

BACKGROUND/OBJECTIVES: Plasma zinc is an important biomarker of zinc status, but the concentration is depressed by inflammation. SUBJECTS/METHODS: Apparently healthy adults, who tested positive twice for human immunodeficiency virus (HIV) but who had not reached stage IV or clinical AIDS, were randomly allocated to receive a food supplement (n=17 and 21) or the food plus a micronutrient capsule (MN; n=10 men and n=33 women) containing 15 mg zinc/day. We used the inflammation biomarkers, C-reactive protein (CRP) and alpha1-acid glycoprotein (AGP), to identify subjects with and without inflammation and determine the effect of inflammation on the response of plasma zinc concentrations to the MN and food supplements. RESULTS: There were no differences between men and women either in plasma zinc or in the responses to the supplements and their data were combined. Plasma zinc was lower in those with inflammation than without. Repeated measures analysis of variance (ANOVA) showed that inflammation blocked increases in plasma zinc, and there was an approximate 10% increase in plasma zinc concentration in response to the MN supplement (P=0.023) in those without inflammation. Subgroup analysis showed mean changes in plasma zinc of 0.95 and -0.83 micromol/l (P=0.031) in response to the MN and food treatments, respectively, in those without inflammation at both time points. CONCLUSIONS: Inflammation seems to block any increase in plasma zinc after MN supplement and it is important to identify those without inflammation to determine the effectiveness of a zinc supplementation program.

The effects of maternal and infant vitamin A supplementation on vitamin A status: a randomised trial in Kenya.

Postpartum vitamin A supplementation of mothers and infants is recommended, but the efficacy has been questioned. In this double-blind, placebo-controlled trial, Kenyan mother-infant pairs were randomised to maternal vitamin A (400,000 IU) or placebo <24 h postpartum, and infant vitamin A (100,000 IU) or placebo at 14 weeks. Milk retinol was determined at weeks 4, 14 and 26, and maternal and infant serum retinol at weeks 14 and 26. Infant retinol stores were assessed at week 26, using a modified relative dose response (MRDR) test. Among 564 women, serum retinol at 36 weeks gestation was 0.81 (SD 0.21) micromol/l, and 33.3% were<0.7 micromol/l. Maternal serum retinol was not different between groups, but milk retinol was higher in the vitamin A group: (0.67 v. 0.60 micromol/l; 0.52 v. 0.44 micromol/l; 0.50 v. 0.44 micromol/l at 4, 14 and 26 weeks, respectively). When expressed per gram fat, milk retinol was higher in the vitamin A group only at 4 weeks. Infant serum retinol was not different between groups. However, although most infants had deficient vitamin A stores (MRDR>0.06%) at 26 weeks, vitamin A to infants, but not mothers, resulted in a lower proportion of infants with deficient vitamin A stores (69 v. 78 %). High-dose postpartum vitamin A supplementation failed to increase serum retinol and infant stores, despite modest effects on milk retinol. Infant supplementation, however, increased stores. There is a need for a better understanding of factors affecting absorption and metabolism of vitamin A.

Geophagy, iron status and anaemia among primary school children in Western Kenya.

As part of a cross-sectional study among 156 primary school children (median age 13 years, range 10-18) in Western Kenya, geophagy was assessed through interviews. 114 (73.1%) of these children reported eating soil daily. Haemoglobin levels were determined in all 156 children and serum ferritin concentrations in 135. The mean haemoglobin (Hb) concentration was 12.7 g/dl, and median ferritin concentration 27.2 microg/l. Both the proportion of anaemic (Hb < 11.0 g/dl) and of iron-depleted (ferritin < 12 microg/l) children was significantly higher among the geophageous children than among the nongeophageous (9.6% vs. 0% anaemia; P = 0.037; 18.4% vs. 5.4% iron depletion; P = 0.046). Serum ferritin and haemoglobin concentrations were not correlated (r = 0. 13 5; P = 0. 100). Multiple regression analysis showed that geophagy, hookworm eggs per gram faeces and malaria parasite counts per microl blood were independent predictors of serum ferritin, when controlling for other helminth infections, age and sex, and socio-economic and educational background of the children's families and family size (y = 36.038-11.247(geophagy) -- 0.010(hookworm epg) + 0.001(malaria parasite counts); R2 = 0.17). Multiple regression analysis with haemoglobin as dependent variable and the same independent variables did not reveal any significant predictors. Analysis of the soil eaten by the children revealed a mean HCl-extractable iron content of 168.9 mg/kg (SD 44.9). Based on the data on the amounts eaten daily and this mean iron content, soil could provide on average 4.7 mg iron to a geophageous child (interquartile range 2.1-7.1 mg), which is equivalent to 32% of the Recommended Nutrient Intake (RNI) for girls (interquartile range 14-48%) or 42% of the RNI for boys (interquartile range 19-63%). Iron depletion and anaemia are associated with geophagy, but only serum ferritin concentrations were shown to be dependent upon geophagy in the regression model. From the cross-sectional data no inference about causality can be made. To clarify the possible causal relationships involved, longitudinal studies and iron-supplementation intervention studies are needed.

The association between oral leukoplakia and use of tobacco, alcohol and khat based on relative risks assessment in Kenya.

A case-control study was conducted to determine the significance of tobacco, alcohol and khat (Catha edulis) chewing habits in the development of oral leukoplakia among Kenyans aged 15 yr and over. In a house-to-house survey, 85 cases and 141 controls matched for sex, age and cluster origin was identified and compared for these risk factors. Smoking unprocessed tobacco (Kiraiku) with a relative risk (RR) of 10.0 (95% confidence interval (CI) = 2.9-38.4) and smoking cigarettes (RR = 8.4; 95% CI = 4.1-17.4) were the most significant factors. While the RR associated with smoking cigarettes alone was 4.5 (95% CI = 1.9-10.8), smoking of both products (RR = 15.2) suggested probable synergy or additive effects. Oral leukoplakia in 18 cases could not be attributed to smoking tobacco. Commercial beer, wines and spirits were relatively weak, but statistically significant, risk factors. Traditional beer, khat and chilies were not significantly associated with oral leukoplakia.

Biocidal effects and residual glutaraldehyde in cellulosic and synthetic polymers.

The amount of leachable glutaraldehyde from medical grade Cuprophan 150PM (cellulose based) and AN69S (a copolymer of acrylonitrile and sodium methallyl sulphonate) membranes, and polyproprene plates following 72 hr immersion in 2% alkaline glutaraldehyde was determined. After rinsing the materials for 30 minutes in distilled water at 37 degrees C, the mean concentration of leachable glutaraldehyde from Cuprophan 150 PM (8. 60 +/- 0.55 micrograms/g) was significantly greater than that from AN69S membrane (6.50 +/- 0.60 micrograms/g), (p < 0.01). The mean leachable glutaraldehyde from plates was 0.30 +/- 0.15 microgram/g. There was a significant decrease in the mean leachable glutaraldehyde from AN69S (5.35 +/- 0.25 micrograms/g) after second immersion (p < 0.05). The concentration of leachable glutaraldehyde in the plates and Cuprophan 150PM remained relatively unchanged. Absence of growth following infusion of 2% alkaline glutaraldehyde into blood contaminated miniature dialyzers containing high microbial loads of selected bioindicator organisms (S. aureus, P. aeruginosa, B. subtilis (Var globigii) spores, M. gordonae, A. niger spores and attenuated polio virus) demonstrated its effectiveness under environmental conditions that were conducive to high resistance. These findings indicate that 2% alkaline glutaraldehyde is readily washed from the three polymer materials that were studied and its accumulation following repeated exposure was not evident. Its application in pre-sterilization treatment of heavily contaminated invasive polymer based devices seemed feasible.