Biomedical subjects

Henrik Friis

Publications and source records attributed to Henrik Friis.

31 records · Page 2Linked to original sources

PubMed2004

Effects of iron and multimicronutrient supplementation on geophagy: a two-by-two factorial study among Zambian schoolchildren in Lusaka.

Geophagy has been associated with iron deficiency and anaemia, but no causal relationship has been established. To clarify this, we conducted a two-by-two factorial randomised, controlled trial on the effect of iron and multimicronutrient supplementation on geophagy in Zambian schoolchildren in Lusaka, from February to December 2001. Of the 406 children, 212 (52.2%) were girls and the mean (range) age was 10.2 (7-15) years. Geophagy was reported by 302 (74.4%) and more often in girls than in boys (80.2 vs. 67.7%, P = 0.007). The mean (range) daily earth intake was 25.2 (1-200) g. Geophageous children had more often geophageous relatives than non-geophageous children (79.5 vs. 1.9%, P < 0.001). Geophageous children had lower serum ferritin (20.5 vs. 25.0 microg/l, P = 0.032) but not haemoglobin (Hb) (129.2 vs. 130.4 g/l, P = 0.59), than non-geophageous. Among those with Hb < 130 g/l, geophageous children had significantly higher prevalence (53.7 vs. 30.6%, P = 0.024) of Ascaris lumbricoides infection than non-geophageous. The prevalence of geophagy (74.4 to 51.6%) and the intake of earth (25.3 to 15.0 g/day) declined (P = 0.001 and P < 0.001, respectively) among the 220 (54.2%) children followed-up. In bivariate analysis, non-iron supplementation reduced the prevalence of geophagy more than iron supplementation did, but this was not confirmed in the multiple logistic regression analysis. Multimicronutrients had no effect on either geophagy prevalence or earth intake. Geophagy was prevalent and associated with iron deficiency, but iron supplementation had no effects on geophageous behaviour. Geophagy could be a copied behaviour and the association between geophagy and iron deficiency due to impaired iron absorption following earth eating.

Adolescent↗

PubMed2004

Maternal body composition, HIV infection and other predictors of gestation length and birth size in Zimbabwe.

The role of maternal infections, nutritional status and obstetric history in low birth weight is not clear. Thus, the objective of the present study was to assess the effects of maternal HIV infection, nutritional status and obstetric history, and season of birth on gestation length and birth size. The study population was 1669 antenatal care attendees in Harare, Zimbabwe. A prospective cohort study was conducted as part of a randomised, controlled trial. Maternal anthropometry, age, gravidity, and HIV status and load were assessed in 22nd-35th weeks gestation. Outcomes were gestation length and birth size. Birth data were available from 1106 (66.3%) women, of which 360 (32.5%) had HIV infection. Mean gestation length was 39.1 weeks with 16.6% <37 weeks, mean birth weight was 3030 g with 10.5% <2500 g. Gestation length increased with age in primigravidae, but not multigravidae (interaction, P=0.005), and birth in the early dry season, low arm fat area, multiple pregnancies and maternal HIV load were negative predictors. Birth weight increased with maternal height, and birth in the late rainy and early dry season; primi-secundigravidity, low arm fat area, HIV load, multiple pregnancies and female sex were negative predictors. In conclusion, gestation length and birth weight decline with increasing maternal HIV load. In addition, season of birth, gravidity, maternal height and body fat mass, and infant sex are predictors of birth weight.

Adipose Tissue↗

PubMed2004

Fluoroquinolone antibiotics in a hospital sewage line; occurrence, distribution and impact on bacterial resistance.

In hospital sewage lines, human faecal bacteria are exposed to antibiotics, posing a risk for selection of antibiotic resistant microorganisms. We constructed a system for continuous sampling in a hospital sewage line that allowed us to study longitudinal establishment of bacteria, concentrations of antibiotics, and selection of bacterial resistance in waste water, sediment and biofilm. The focus in this study was on fluoroquinolones, a widely used group of antibiotics with increasing resistance problems. We found low levels of ciprofloxacin and ofloxacin in waste water but high concentrations in sediment. Despite the high levels of fluoroquinolones bound to sediment, we did not find any development of resistance against fluoroquinolones in Enterobacteriacae spp. and faecal enterococci isolated from sediment.

Drug Resistance, Bacterial↗

PubMed2004

Effect of multimicronutrient supplementation on gestational length and birth size: a randomized, placebo-controlled, double-blind effectiveness trial in Zimbabwe.

BACKGROUND: Multiple micronutrient deficiencies may contribute to low birth weight, which is a major global determinant of mortality. OBJECTIVE: We assessed the effect of prenatal multimicronutrient supplementation on gestational length and birth size. DESIGN: We conducted a randomized, placebo-controlled, double-blind effectiveness trial among antenatal care attendees in Harare, Zimbabwe. Pregnant women (22-35 wk of gestation) were randomly allocated to receive a multimicronutrient or placebo supplement daily until delivery. Supplementation with iron and folic acid was part of antenatal care. RESULTS: Of 1669 women, birth data were available from 1106 (66%), of whom 360 (33%) had HIV infection. The mean gestational length was 39.1 wk, and 16.6% of the women had a gestational length < 37 wk. The mean birth weight was 3030 g, and 10.5% of the infants had a birth weight < 2500 g. Multimicronutrient supplementation was associated with tendencies for increased gestational length (0.3 wk; 95% CI: -0.04, 0.6 wk; P = 0.06), birth weight (49 g; -6, 104 g; P = 0.08), and head circumference (0.2 cm; -0.02, 0.4 cm; P = 0.07) but was not associated with low birth weight (birth weight < 2500 g) (relative risk: 0.84; 0.59, 1.18; P = 0.31). The effect of multimicronutrient supplementation on birth weight was not significantly different between HIV-uninfected (26 g; -38, 91 g) and HIV-infected (101 g; -3, 205 g) subjects (interaction, P > 0.10). CONCLUSION: Antenatal multimicronutrient supplementation may be one strategy to increase birth size.

Birth Weight↗

PubMed2003

Iron, haptoglobin phenotype, and HIV-1 viral load: a cross-sectional study among pregnant Zimbabwean women.

BACKGROUND: Viral load is a determinant of HIV-1 progression and transmission. Iron status and the phenotype of haptoglobin, a heme-binding acute phase reactant, may be determinants of viral load. We aimed to describe the effect of iron status, haptoglobin phenotype (Hp), and other predictors on HIV-1 viral load. METHODS: Based on a cross-sectional study among 1669 antenatal care attenders (22-35 weeks) in Zimbabwe, 526 (31.5%) were found to be HIV infected. The role of season, age, gravidity, gestational age, malaria parasitemia, Hp, and elevated serum alpha(1)-antichymotrypsin (ACT) as well as serum ferritin, folate, retinol, and beta-carotene on HIV viral load among the 526 HIV-infected women was assessed using multiple linear regression analysis. RESULTS: The distribution of Hp 1-1 (32%), Hp 2-1 (48%), and Hp 2-2 (20%) was not different from that of 53 uninfected women. Mean viral load was 3.85 log(10) (95% CI: 3.77-3.93) genome equivalents (geq)/mL, ranging from 3.77 (95% CI: 3.64-3.90) geq/mL in women with Hp 1-1 to 4.05 (95% CI: 3.81-4.21) geq/mL in women with Hp 2-2. With elevated serum ACT controlled for, women with Hp 2-2 had viral loads twice (95% CI: 1.4-4.0, p =.002) that of women with Hp 1-1, whereas those with serum ferritin <6 micro g/L had viral loads less than one third (95% CI: 0.13-0.53, p =.013) that of women with serum ferritin >24 micro g/L. Viral loads were also higher in women enrolled in the early rainy season compared with the dry season, in gravidae 4+ compared with gravidae 1 through 3, and in those with moderately elevated compared with low serum alpha(1)-antichymotrypsin, but neither age, gestational age, serum folate, serum retinol, nor serum beta-carotene were predictors. CONCLUSION: Storage iron, Hp 2-2, and elevated ACT are independent positive predictors of HIV-1 viral load. The positive relationship between serum ferritin and viral load was not the result of an acute phase response or iron accumulation with advanced HIV infection. A possible detrimental role of iron in HIV infection would have serious public health implications.

Female↗

PubMed2003

Reference values and predictors of white blood cell subset counts: a cross-sectional study among HIV seronegative pregnant women in Zimbabwe.

OBJECTIVE: To identify predictors and develop reference values of white blood cell subset counts for pregnant black women in Zimbabwe. STUDY DESIGN: In this cross-sectional study, multiple linear regression (MLR) analysis was employed to assess the relationship of WBC subset counts with age, gestational age, gravidity, season, serum retinol, beta-carotene, ferritin, folate and alpha-1 antichymotrypsin among 998 women 22-35 weeks pregnant attending antenatal care (ANC) in Harare, Zimbabwe. RESULTS: Mean age was 24.0 (95% CI; 23.6-24.4), range 14-45 years. The mean gestational age was 29.2 (95% CI; 29.0-29.4), range 22-35 weeks. Median gravidity was 2, range 1-9. Predictors of neutrophil counts were gestational age, season and serum ferritin, the latter in interaction with gravidity (interaction, p = 0.016). Mean lymphocyte count was 0.13 x 10(9)cells/l higher in gravida >4 than gravida 1-3, and 0.35 x 10(9)cells/l higher in the late rainy than other seasons. Predictors of monocyte counts were gestational age, serum folate and season, while eosinophil counts declined with advancing gestation. Reference values adjusted or unadjusted for identified predictors were different from those of pregnant and non-pregnant white women reported in the literature. CONCLUSIONS: Gravidity, season and micronutrient status influence WBC counts during pregnancy and therefore are of physiological and clinical importance. WBC reference values in the literature were not applicable obviating the need for local reference values.

Adolescent↗

PubMed2003

Hypothesis: Vitamin A supplementation and childhood mortality: amplification of the non-specific effects of vaccines?

Most areas of health research will have accepted data and a dominating interpretation. If the interpretation is not correct, contradictions will accumulate, and it will eventually become clear that the current interpretation is untenable. In this situation, the best hypothesis is the one that accounts for all of the known data as well as the apparent contradictions. The area of vitamin A supplementation and childhood mortality in developing countries is afflicted with many contradictions and there is a need for a new hypothesis. We propose that the effect of vitamin A supplementation may depend on the amplification of non-specific effects of vaccines on childhood mortality.

Adjuvants, Immunologic↗

PubMed2002

Haemoconcentration associated with low vitamin A status can mask anaemia.

As part of a pig study to elucidate the interactions between low vitamin A status and helminth infections, surprisingly, we observed higher haemoglobin levels and packed cell volumes in the pigs with low vitamin A status. A possible haemoconcentration effect, due to some disturbance in the regulation of the extracellular fluid volume, could lead to underestimation of the prevalence of anaemia in vitamin A deficient human populations. Therefore, this phenomenon needs to be further clarified in studies involving determination of plasma volumes.

Anemia↗

PubMed2002

HIV-1 viral load and elevated serum alpha(1)-antichymotrypsin are independent predictors of body composition in pregnant Zimbabwean women.

Human immunodeficiency virus (HIV) infection affects body composition, but their relationship has not been studied in pregnant women. We conducted a cross-sectional study among 1669 women receiving antenatal care between 22 and 35 wk of gestation in Harare, Zimbabwe. The role of HIV-1 status and viral load, malaria and elevated serum alpha(1)-antichymotrypsin (ACT, an acute phase protein) in weight, body mass index (BMI), arm circumference (AC), triceps skinfold thickness (TSF), and arm muscle (AMA) and fat (AFA) area were assessed using multiple linear regression analysis. The mean (range) age was 24.4 (14-45) y and gestational age 29 (22-35) wk. HIV infection was present in 31.5% of the women, malaria parasitemia in 0.4% and 11.4% had serum ACT >0.4 g/L. There was no difference in any anthropometric variable between HIV-infected and uninfected women. However, women with viral loads (genome equivalents/mL) between 4 and 5 and >5 log(10) had 1.1 [95% confidence interval (CI): -0.3, 2.3] and 2.5 (95% CI: 0.1, 5.1) kg lower weights compared with uninfected women; this was explained by losses of both AFA and AMA. Malaria parasitemia was associated with 6 cm(2) (95% CI: 0.4; 11.8) or 25% lower AMA. Elevated serum ACT was a negative predictor of all anthropometric variables, i.e., levels between 0.3 and 0.4, 0.4 and 0.5 and >0.5 g/L were associated with 1, 2 and 6 kg lower mean body weights, respectively. Despite the limitations of a cross-sectional design, we conclude that arm fat and muscle areas, reflecting body fat and lean body mass, seem to be unaffected in the majority of HIV-infected pregnant women, but decline with increasing viral loads. The effects of viral load are not explained by elevated serum ACT, which is a strong independent predictor of all anthropometric variables.

Adolescent↗

PubMedDate not supplied

Serum ferritin, alpha-tocopherol, beta-carotene and retinol levels in lymphatic filariasis.

Based on a cross-sectional study conducted among 100 adults in 1993 in Tanga, Tanzania, the relationship between Wuchereria bancrofti infection and markers of iron, vitamin A and vitamin E status was assessed. Potential predictors assessed were elephantiasis, hydrocoele, W. bancrofti microfilaria intensity and antigen concentration, and intensity of Schistosoma haematobium, hookworm, Trichuris trichiura and Ascaris lumbricoides infection, while controlling for age, sex and elevated serum alpha-1 antichymotrypsin. Of the 100 adults, 62 had W. bancrofti antigenaemia and 43 microfilaraemia, and 21 had elephantiasis. Of the 64 males, 31 had hydrocoele. W. bancrofti microfilaria intensity was a positive predictor of serum ferritin and a negative predictor of serum alpha-tocopherol. In contrast, negative relationships observed between W. bancrofti microfilaria intensity and serum beta-carotene and retinol were not significant. Neither antigen concentration nor clinical manifestations were predictors of micronutrient status. Intensity of hookworm infection was associated with lower serum ferritin. S. haematobium egg output was not a significant predictor of serum ferritin, but was a positive predictor of serum beta-carotene. In conclusion, W. bancrofti microfilaria intensity was associated with higher serum ferritin, but lower serum alpha-tocopherol. The associations probably reflect increased oxidative stress due to microfilariaehost interactions, which could play a role in the pathogenesis.

Adolescent↗

PubMedDate not supplied

Effects of multimicronutrient supplementation on helminth reinfection: a randomized, controlled trial in Kenyan schoolchildren.

A randomized, placebo-controlled, double-blind, two-by-two factorial trial was carried out among 977 schoolchildren from 19 primary schools in Nyanza Province, Kenya from February 1995 to February 1996. The interventions were multimicronutrient supplementation (vitamin A, 1000 micrograms; vitamin B1, 1.4 mg; vitamin B2, 1.6 mg; vitamin B6, 1.7 mg; vitamin B12, 2.0 micrograms; folate, 150 micrograms; niacin, 16 mg; vitamin C, 50 mg; vitamin D, 5 micrograms; vitamin E, 8 mg; iron, 18 mg; zinc, 20 mg; copper, 2.0 mg; iodine, 150 micrograms; selenium, 40 micrograms) and multihelminth chemotherapy (albendazole 600 mg in a single dose and/or praziquantel 40 mg/kg in a single dose). This paper reports the effects of the supplementation given on all school days on reinfection with hookworm, Ascaris lumbricoides, Trichuris trichiura and Schistosoma mansoni after 11 months. Baseline prevalence and geometric mean intensity for hookworm, A. lumbricoides, T. trichiura and S. mansoni in all children investigated were 54.7%, 13.8%, 45.6% and 70.0%, respectively and 8.6, 2.7, 5.9 and 19.4 eggs per gram (epg), respectively. Children received a mean of 2.3 multimicronutrient/placebo tablets per school week, giving a compliance rate of 46%. Children given multimicronutrients had a slightly, but significantly, lower intensity of S. mansoni reinfection compared with children given placebo (5.5 epg vs. 7.7 epg, P = 0.047). Multiple linear regression analyses controlling for baseline infection status confirmed this, as children who received micronutrients were reinfected with S. mansoni at only 69% of the intensity of those who received placebo. Multiple logistic regression analyses revealed that micronutrient supplementation was associated with a lower S. mansoni reinfection rate (odds ratio = 0.7) although this was only of borderline significance (P = 0.090). There were no significant differences in reinfection rates or intensities of hookworm, A. lumbricoides and T. trichiura. The effect on S. mansoni infection intensity is particularly interesting given the low compliance, suggesting that full micronutrient supplementation might have a role to play in S. mansoni control programmes.

Adolescent↗

PubMedDate not supplied

Subclinical mastitis among HIV-infected and uninfected Zimbabwean women participating in a multimicronutrient supplementation trial.

Subclinical mastitis, defined as raised milk sodium/potassium (Na/K) ratio is common and associated with poor infant growth and increased mother-to-child HIV transmission. In 1996-97, we conducted a randomized controlled trial of multiple micronutrient supplementation, at recommended daily allowance levels, from 22 to 35 weeks gestation until 3 months post-partum, on the prevalence and severity of subclinical mastitis among 84 HIV-infected and 83 HIV-uninfected lactating Zimbabwean women and on their infants' growth. Spot milk samples collected before 4.5 months post-partum were analysed for Na/K ratio by flame photometry. There was no significant difference in prevalence of subclinical mastitis between HIV-infected and HIV-uninfected women. After controlling for infant age at time of sampling, micronutrient-supplemented HIV-infected women had non-significantly (P = 0.08) lower geometric mean Na/K ratio (0.43, 95% CI 0.35-0.51) than HIV-infected women given placebo (0.51, 95% CI 0.42-0.61). Micronutrient supplementation had no effect on the prevalence of subclinical mastitis among HIV-uninfected women (odds ratio [OR] = 1.26, 95% CI 0.45-3.51, P = 0.80) but induced a borderline decrease in prevalence (OR = 2.82, 95% CI 0.96-8.26, P = 0.07) among HIV-infected women. Infant weight between 1.5 and 4.5 months was lower in women with higher milk Na/K ratio. Thus, the importance of subclinical mastitis for infant growth suggests that further investigations to decrease the condition, perhaps using higher micronutrient doses, are warranted.

Adult↗

PubMedDate not supplied

Entomophagy among the Luo of Kenya: a potential mineral source?

Primary objective To determine the iron, zinc, and calcium content in different insects commonly eaten among the Luo of Kenya. Research design A cross-sectional design was chosen for the study in order to determine the insects eaten and their mineral content during a specific season.Methods and procedures Five different insect species were identified and collected with the help of local informants in the Nyang'oma sublocation of the Bondo district in western Kenya, and were analysed for iron, zinc and calcium contents. Main outcomes and results The iron content ranged from 18 to 1562 mg/100 g dry matter, the zinc content from 8 to 25 mg/100 g, and the calcium content from 33 to 341 mg/100 g in five different insects, onyoso mammon (ant), oyala (termite), ogawo (termite), agaor (termite), onjiri mammon (cricket). Conclusions Insect eating could prove to be a valuable measure to combat, especially, iron and zinc deficiency in developing countries.

Aged↗