Poison prevention practices and medically attended poisoning in young children: multicentre case-control study.

INTRODUCTION: Childhood poisonings are common, placing a substantial burden on health services. Case-control studies have found inconsistent evidence about modifiable risk factors for poisonings among children aged 0-4 years. This study quantifies associations between poison prevention practices and medically attended poisonings in children aged 0-4 years. METHODS: Multicentre case-control study conducted at hospitals, minor injury units and family practices from four study centres in England between 2010 and 2013. Participants comprised 567 children presenting with unintentional poisoning occurring at home and 2320 community control participants matched on age, sex, date of event and study centre. Parents/caregivers provided data on safety practices, safety equipment use, home hazards and potential confounders by means of self-completion questionnaires. Data were analysed using conditional logistic regression. RESULTS: Compared with community controls, parents of poisoned children were significantly more likely not to store medicines out of reach (adjusted OR (AOR) 1.59; 95% CI 1.21 to 2.09; population attributable fraction (PAF) 15%), not to store medicines safely (locked or out of reach (AOR 1.83; 95% CI 1.38 to 2.42; PAF 16%) and not to have put all medicines (AOR 2.11; 95% CI 1.54 to 2.90; PAF 20%) or household products (AOR 1.79, 95% CI 1.29 to 2.48; PAF 11%) away immediately after use. CONCLUSIONS: Not storing medicines out of reach or locked away and not putting medicines and household products away immediately after use increased the odds of secondary care attended poisonings in children aged 0-4 years. If associations are causal, implementing these poison prevention practices could each prevent between 11% and 20% of poisonings.

Validation of a home safety questionnaire used in a series of case-control studies.

OBJECTIVE: To measure the validity of safety behaviours, safety equipment use and hazards reported on a questionnaire by parents/carers with children aged under 5 years participating in a series of home safety case-control studies. METHODS: The questionnaire measured safety behaviours, safety equipment use and hazards being used as exposures in five case-control studies. Responses to questions were compared with observations made during a home visit. The researchers making observations were blind to questionnaire responses. RESULTS: In total, 162 families participated in the study. Overall agreement between reported and observed values of the safety practices ranged from 48.5% to 97.3%. Only 3 safety practices (stair gate at the top of stairs, stair gate at the bottom of stairs, stairs are carpeted) had substantial agreement based on the κ statistic (k=0.65, 0.72, 0.74, respectively). Sensitivity was high (≥70%) for 19 of the 30 safety practices, and specificity was high (≥70%) for 20 of the 30 practices. Overall for 24 safety practices, a higher proportion of respondents over-reported than under-reported safe practice (negative predictive value>positive predictive value). For six safety practices, a higher proportion of respondents under-reported than over-reported safe practice (negative predictive value

Keeping children safe at home: protocol for a matched case-control study of modifiable risk factors for poisoning.

BACKGROUND: Childhood unintentional and suspected poisonings are a serious public health problem. Evidence from systematic reviews demonstrates that home safety education in combination with safety equipment provision increases the safe storage of medicines and other products. There is lack of evidence that poisoning prevention practices reduce poisoning rates. OBJECTIVES: To estimate ORs for medically attended poisonings in children aged 0-4 years for items of safety equipment, home hazards and parental safety practices aimed at preventing poisoning, and to explore differential effects by child and family factors. DESIGN: Multicentre case-control study in UK hospitals with validation of parent-reported exposures using home observations. Cases are aged 0-4 years with a medically attended poisoning occurring at home, matched on age and sex with community controls. Children attending hospital for other types of injury will serve as unmatched hospital controls. Matched analyses will use conditional logistic regression; unmatched analyses will use unconditional logistic regression to adjust for confounding variables. The study requires 266 poisoning cases and 1064 matched controls to detect an OR of 0.64 for safe storage of medicinal products and of 0.65 for non-medicinal products, with 80% power, a 5% significance level and a correlation between exposures in cases and controls of 0.1. MAIN OUTCOME MEASURES: Unintentional childhood poisoning. DISCUSSION: This will be the largest study to date exploring modifiable risk factors for poisoning in young children. Findings will inform: policy makers developing poison prevention strategies, practitioners delivering poison prevention interventions, parents to reduce the risk of poisoning in their homes.

Increasing fish consumption does not affect genotoxicity markers in the colon in an intervention study.

Observational studies suggest that fish consumption is associated with a decreased colorectal cancer (CRC) risk. A possible mechanism by which fish could reduce CRC risk is by decreasing colonic genotoxicity. However, concerns have also been raised over the levels of toxic compounds found in mainly oil-rich fish, which could increase genotoxicity. Therefore, the objective was to investigate the effects of fish on genotoxicity markers in the colon in a randomized controlled parallel intervention study. For a period of 6 months, subjects were randomly allocated to receive two extra weekly portions of (i) oil-rich fish (salmon), (ii) lean fish (cod) or (iii) just dietary advice (DA). The Comet Assay was used to measure the DNA damage-inducing potential of fecal water (n = 89) and DNA damage in colonocytes (n = 70) collected pre- and post-intervention as markers of genotoxicity. Genotoxicity of fecal water was not markedly changed after fish consumption: 1.0% increase in tail intensity (TI) [95% confidence interval (CI) -5.1; 7.0] in the salmon group and 0.4% increase in TI (95% CI -5.3; 6.1) in the cod group compared with the DA group. DNA damage in colonocytes was also not significantly changed after fish consumption, in either the salmon group (-0.5% TI, 95% CI -6.9; 6.0) or cod group (-3.3% TI, 95% CI -10.8; 4.3) compared with the DA group. Measurements of genotoxicity of fecal water and DNA damage in colonocytes did not correlate (r = 0.06, n = 34). In conclusion, increasing consumption of either oil-rich or lean fish did not affect genotoxicity markers in the colon.

Increased consumption of fatty and lean fish reduces serum C-reactive protein concentrations but not inflammation markers in feces and in colonic biopsies.

Fish consumption is associated with a reduced colorectal cancer risk. A possible mechanism by which fish consumption could decrease colorectal cancer risk is by reducing inflammation. However, thus far, intervention studies investigating both systemic and local gut inflammation markers are lacking. Our objective in this study was to investigate the effects of fatty and lean fish consumption on inflammation markers in serum, feces, and gut. In an intervention study, participants were randomly allocated to receive dietary advice (DA) plus either 300 g of fatty fish (salmon) or 300 g of lean fish (cod) per week for 6 mo, or only DA. Serum C-reactive protein (CRP) concentrations were measured pre- and postintervention (n = 161). In a subgroup (n = 52), we explored the effects of the fish intervention on fecal calprotectin and a wide range of cytokines and chemokines in fecal water and in colonic biopsies. Serum CRP concentrations were lower in the salmon (-0.5 mg/L; 95% CI -0.9, -0.2) and cod (-0.4 mg/L; 95% CI -0.7, 0.0) groups compared with the DA group. None of the inflammation markers in fecal water and colonic biopsies differed between the DA group and the groups that consumed extra fish. In conclusion, increasing salmon or cod consumption for 6 mo resulted in lower concentrations of the systemic inflammation marker CRP. However, exploratory analysis of local markers of inflammation in the colon or feces did not reveal an effect of fish consumption.

Evaluating implementation of a fire-prevention injury prevention briefing in children's centres: Cluster randomised controlled trial.

BACKGROUND: Many developed countries have high mortality rates for fire-related deaths in children aged 0-14 years with steep social gradients. Evidence-based interventions to promote fire safety practices exist, but the impact of implementing a range of these interventions in children's services has not been assessed. We developed an Injury Prevention Briefing (IPB), which brought together evidence about effective fire safety interventions and good practice in delivering interventions; plus training and facilitation to support its use and evaluated its implementation. METHODS: We conducted a cluster randomised controlled trial, with integrated qualitative and cost-effectiveness nested studies, across four study sites in England involving children's centres in disadvantaged areas; participants were staff and families attending those centres. Centres were stratified by study site and randomised within strata to one of three arms: IPB plus facilitation (IPB+), IPB only, usual care. IPB+ centres received initial training and facilitation at months 1, 3, and 8. Baseline data from children's centres were collected between August 2011 and January 2012 and follow-up data were collected between June 2012 and June 2013. Parent baseline data were collected between January 2012 and May 2012 and follow-up data between May 2013 and September 2013. Data comprised baseline and 12 month parent- and staff-completed questionnaires, facilitation contact data, activity logs and staff interviews. The primary outcome was whether families had a plan for escaping from a house fire. Treatment arms were compared using multilevel models to account for clustering by children's centre. RESULTS: 1112 parents at 36 children's centres participated. There was no significant effect of the intervention on families' possession of plans for escaping from a house fire (adjusted odds ratio (AOR) IPB only vs. usual care: 0.93, 95%CI 0.58, 1.49; AOR IPB+ vs. usual care 1.41, 95%CI 0.91, 2.20). However, significantly more families in the intervention arms reported more behaviours for escaping from house fires (AOR IPB only vs. usual care: 2.56, 95%CI 01.38, 4.76; AOR IPB+ vs. usual care 1.78, 95%CI 1.01, 3.15). CONCLUSION: Our study demonstrated that children's centres can deliver an injury prevention intervention to families in disadvantaged communities and achieve changes in home safety behaviours.

Calcium absorption is not increased by caseinophosphopeptides.

BACKGROUND: One of the suggested health benefits of caseinophosphopeptides (CPPs) is their ability to enhance calcium absorption. This possibility is based on the assumption that they resist proteolysis in the upper gastrointestinal tract and maintain calcium in a soluble form at alkaline pH in the distal ileum. OBJECTIVE: The effects of CPP-enriched preparations (containing candidate functional food ingredients) on calcium absorption from a calcium lactate drink were tested. DESIGN: A randomized crossover trial was undertaken in 15 adults in whom we measured the absorption of calcium from a calcium lactate drink (drink A: 400 mg Ca as lactate) and 2 preparations enriched with forms of CPP (1.7 g each; drinks B and C). Both drinks B and C contained 400 mg Ca as calcium lactate plus approximately 100 mg CPP-derived calcium). Each volunteer received the 3 drinks in random order. Absorption was measured by the dual-label calcium stable-isotope technique. RESULTS: The quantity of calcium absorbed was significantly lower from drink A (103 mg) than from drink B (117 mg; P = 0.012) or drink C (121 mg; P = 0.002), which indicated a positive effect of the CPPs. However, because the CPP preparations contributed additional calcium besides that found in the calcium lactate (drink A), fractional absorption of calcium from drink B (23%) was slightly but significantly (P = 0.015) lower than that from drink A (26%). CONCLUSIONS: The differences in calcium absorption are unlikely to have any biological significance. CPPs are unsuitable as candidate ingredients for functional foods that are designed to deliver improved calcium nutrition.

Absorption of calcium from milks enriched with fructo-oligosaccharides, caseinophosphopeptides, tricalcium phosphate, and milk solids.

BACKGROUND: Adequate intakes of calcium are required for optimal bone health and protection against chronic disease. Dairy products are an excellent source of calcium. OBJECTIVE: The absorption of calcium from a range of fortified milks was measured in humans with the use of stable isotopes. DESIGN: Fifteen volunteers participated in a randomized, controlled, double-blind crossover study. Five types of semi-skimmed (1.9% fat) milk drinks were administered with a light breakfast: standard milk (control milk); milk enriched with calcium from milk solids and tricalcium phosphate [(TCP) MSS milk]; milk enriched with calcium from concentrated milk (CON milk); milk with added fructo-oligosaccharides [(FOSs) FOS milk]; and milk with added caseinophosphopeptides [(CPPs) CPP milk]. All the milks were labeled with 42Ca as CaCl2. The MSS milk was also labeled with 44Ca as TCP. The quantity of calcium in each drink was kept the same by varying the volume given. RESULTS: Calcium absorption did not differ significantly between the control milk and the calcium-fortified milks (MSS and CON milk) or the FOS and CPP milks. However, calcium absorption from the TCP added to the MSS milk was significantly higher than that from the control milk (27.5 +/- 7.6% and 24.5 +/- 7.3%, respectively; P = 0.003). CONCLUSIONS: Calcium-enriched milks are a valuable source of well-absorbed calcium. Absorption of added calcium as TCP was higher than that of calcium from the control milk, but the addition of FOSs or CPPs did not significantly increase calcium absorption. Further research is needed to ascertain the cost-effectiveness and public health benefits of consuming fortified milks.

Modifiable risk factors for scald injury in children under 5 years of age: A Multi-centre Case-Control Study.

OBJECTIVE: To determine the relationship between a range of modifiable risk factors and medically attended scalds in children under the age of 5 years. METHODS: Multicentre matched case-control study in acute hospitals, minor injury units and GP practices in four study centres in England. Cases comprised 338 children under 5 presenting with a scald, and 1438 control participants matched on age, gender, date of event and study centre. Parents/caregivers completed questionnaires on safety practices, safety equipment use, home hazards and potential confounders. Odds ratios were estimated using conditional logistic regression. RESULTS: Parents of cases were significantly more likely than parents of controls to have left hot drinks within reach of their child (adjusted odds ratio (AOR) 2.33, 95%CI 1.63 to 3.31; population attributable fraction (PAF) 31%). They were more likely not to have taught children rules about climbing on kitchen objects (AOR 1.66, 95%CI 1.12 to 2.47; PAF 20%); what to do or not do when parents are cooking (AOR 1.95, 95%CI 1.33 to 2.85; PAF 26%); and about hot things in the kitchen (AOR 1.89, 95%CI 1.30 to 2.75; PAF 26%). CONCLUSIONS: Some scald injuries may be prevented by parents keeping hot drinks out of reach of children and by teaching children rules about not climbing on objects in the kitchen, what to do or not do whilst parents are cooking using the top of the cooker and about hot objects in the kitchen. Further studies, providing a more sophisticated exploration of the immediate antecedents of scalds are required to quantify associations between other hazards and behaviours and scalds in young children.

Prevention of childhood poisoning in the home: overview of systematic reviews and a systematic review of primary studies.

Unintentional poisoning is a significant child public health problem. This systematic overview of reviews, supplemented with a systematic review of recently published primary studies synthesizes evidence on non-legislative interventions to reduce childhood poisonings in the home with particular reference to interventions that could be implemented by Children's Centres in England or community health or social care services in other high income countries. Thirteen systematic reviews, two meta-analyses and 47 primary studies were identified. The interventions most commonly comprised education, provision of cupboard/drawer locks, and poison control centre (PCC) number stickers. Meta-analyses and primary studies provided evidence that interventions improved poison prevention practices. Twenty eight per cent of studies reporting safe medicine storage (OR from meta-analysis 1.57, 95% CI 1.22-2.02), 23% reporting safe storage of other products (OR from meta-analysis 1.63, 95% CI 1.22-2.17) and 46% reporting availability of PCC numbers (OR from meta-analysis 3.67, 95% CI 1.84-7.33) demonstrated significant effects favouring the intervention group. There was a lack of evidence that interventions reduced poisoning rates. Parents should be provided with poison prevention education, cupboard/drawer locks and emergency contact numbers to use in the event of a poisoning. Further research is required to determine whether improving poison prevention practices reduces poisoning rates.

Iron absorption in male C282Y heterozygotes.

BACKGROUND: The suggestion that carriers of the HFE C282Y mutation absorb nonheme iron more efficiently than do carriers of the wild type has public health implications for countries where the C282Y mutation is common and foods are fortified with iron. OBJECTIVE: We investigated the effect of C282Y heterozygosity on nonheme-iron absorption from a diet high in bioavailable iron and from iron-fortified cereals. DESIGN: The subjects were recruited from a parallel study investigating the relation between HFE mutations, habitual diet, and iron status. Iron absorption was measured in 15 wild-type carriers and 15 C282Y heterozygotes aged >/=40 y. Each subject consumed 3 meals of high iron bioavailability (labeled with Fe-57) for 2 d and 2 meals with fortified cereal products (labeled with Fe-54) for the next 3 d. Iron absorption was measured from isotope incorporation into red blood cells 14 d after the last labeled meal and was corrected for utilization of absorbed iron by means of an intravenous infusion of Fe-58. RESULTS: Absorption of Fe-57 with the high-iron-bioavailability diet was 6.8 +/- 6.8% (0.6 +/- 0.6 mg/d) in the wild-type carriers and 7.6 +/- 3.2% (0.7 +/- 0.3 mg/d) in the C282Y heterozygotes. Absorption of Fe-54 with cereal products was 4.9 +/- 2.0% (0.7 +/- 0.3 mg/d) in the wild-type carriers and 5.3 +/- 1.3% (0.8 +/- 0.2 mg/d) in the C282Y heterozygotes. CONCLUSIONS: There was no overall significant difference between C282Y heterozygotes and wild-type men in iron absorption from either dietary nonheme iron or fortified cereal products.

Preventing childhood scalds within the home: Overview of systematic reviews and a systematic review of primary studies.

OBJECTIVE: To synthesise and evaluate the evidence of the effectiveness of interventions to prevent scalds in children. METHODS: An overview of systematic reviews (SR) and a SR of primary studies were performed evaluating interventions to prevent scalds in children. A comprehensive literature search was conducted covering various resources up to October 2012. Experimental and controlled observational studies reporting scald injuries, safety practices and safety equipment use were included. RESULTS: Fourteen systematic reviews and 39 primary studies were included. There is little evidence that interventions are effective in reducing the incidence of scalds in children. More evidence was found that inventions are effective in promoting safe hot tap water temperature, especially when home safety education, home safety checks and discounted or free safety equipment including thermometers and thermostatic mixing valves were provided. No consistent evidence was found for the effectiveness of interventions on the safe handling of hot food or drinks nor improving kitchen safety practices. CONCLUSION: Education, home safety checks along with thermometers or thermostatic mixing valves should be promoted to reduce tap water scalds. Further research is needed to evaluate the effectiveness of interventions on scald injuries and to disentangle the effects of multifaceted interventions on scald injuries and safety practices.

Recruitment and retention strategies and the examination of attrition bias in a randomised controlled trial in children's centres serving families in disadvantaged areas of England.

BACKGROUND: Failure to retain participants in randomised controlled trials and longitudinal studies can cause significant methodological problems. We report the recruitment and retention strategies of a randomised controlled trial to promote fire-related injury prevention in families with pre-school children attending children's centres in disadvantaged areas in England. METHODS: Thirty-six children's centres were cluster randomised into one of three arms of a 12-month fire-related injury prevention trial. Two arms delivered safety interventions and there was one control arm. Retention rates compared the numbers of participants responding to the 12-month questionnaire to the number recruited to the trial. Multivariable random effects logistic regression was used to explore factors independently associated with participant retention. RESULTS: The trial exceeded its required sample size through the use of multiple recruitment strategies. All children's centres remained in the study, despite increased reorganisation. Parent retention was 68% at 12 months, ranging from 65% to 70% across trial arms and from 62% to 74% across trial sites. There was no significant difference in the rates of retention between trial arms (p = 0.58) or between trial sites (p = 0.16). Retention was significantly lower amongst mothers aged 16-25 years than older mothers [adjusted odds ratio (AOR) 0.57, 95% CI 0.41, 0.78], those living in non-owner occupied accommodation than in owner occupied accommodation (AOR 0.53, 95% CI 0.38, 0.73) and those living in more disadvantaged areas (most versus least disadvantaged quintiles AOR 0.50, 95% CI 0.30, 0.82). CONCLUSIONS: Studies recruiting disadvantaged populations should measure and report attrition by socioeconomic factors to enable determination of the extent of attrition bias and estimation of its potential impact on findings. Where differential attrition is anticipated, consideration should be given to over-sampling during recruitment and targeted and more intensive strategies of participant retention in these sub-groups. In transient populations collection of multiple sources of contact information at recruitment and throughout the study may aid retention. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT01452191 ; Date of registration: 10 October 2011, ISRCTN65067450.

Contemporary hazards in the home: keeping children safe from thermal injuries.

OBJECTIVE: To explore the knowledge and reported thermal injury prevention practices among parents of children aged 0-4 years in disadvantaged areas. METHODS: Parents of pre-school children in Children's Centres in four study areas in England (Nottingham, Newcastle, Norwich and Bristol) were interviewed using a structured schedule. Interviews covered smoke alarms, bedtime routines, fire escape plans, other thermal prevention practices and parental knowledge of first aid. RESULTS: Of the 200 respondents, most reported ownership of at least one smoke alarm (n=191, 96%), of which 95% were working. Half reported a fire prevention bedtime routine (n=105, 53%) or fire escape plan (n=81, 42%). Most parents had matches or lighters in the home (n=159, 80%), some stored where children under 5 years of age could reach them (n=30, 19%). There was a high prevalence of irons (n=188, 94%) and hair straighteners (n=140, 70%). A third of both devices were used daily. Just 17 (12%) parents reported leaving hair straighteners, when hot but not in use, in a heatproof bag. Knowledge of correct initial first aid for a small burn was good (n=165, 83%), but parents reported other potentially harmful actions, for example, applying ointment (n=44, 22%). CONCLUSIONS: Most families report at least one working smoke alarm, but many do not have fire escape plans or fire prevention bedtime routines. A number of reported practices could compromise child safety, such as storage of matches or lighters and leaving hair straighteners to cool unprotected. Reappraisal of health promotion messages, in light of new household consumables, is necessary.

Correcting a marginal riboflavin deficiency improves hematologic status in young women in the United Kingdom (RIBOFEM).

BACKGROUND: Moderate riboflavin deficiency is prevalent in certain population groups in affluent countries, but the functional significance of this deficiency is not clear. Studies have indicated a role for riboflavin in the absorption and use of iron. OBJECTIVE: We investigated the effect of riboflavin supplementation on hematologic status in a group of moderately riboflavin-deficient women aged 19-25 y in the United Kingdom. DESIGN: One hundred twenty-three women with biochemical evidence of riboflavin deficiency [erythrocyte glutathione reductase activation coefficient (EGRAC) >1.40] were randomly assigned to receive 2 or 4 mg riboflavin or a placebo for 8 wk. Measurements of hematologic status were made pre- and postsupplementation, and dietary intakes were also assessed; iron absorption was measured in a subgroup of women. RESULTS: One hundred nineteen women completed the intervention. The use of a riboflavin supplement for 8 wk elicited a significant improvement in riboflavin status with a dose response (P < 0.0001). For women who received supplemental riboflavin, an increase in hemoglobin status correlated with improved riboflavin status (P < 0.02). Women in the lowest tertile of riboflavin status at baseline (EGRAC >1.65) showed a significantly greater increase in hemoglobin status in response to the supplement than did women in the first and second tertiles (P < 0.01). Dietary iron intake and iron absorption did not change during the study. CONCLUSIONS: Moderately poor riboflavin status can affect iron status: the lower the riboflavin status, the greater the hematologic benefits of improving status. The results also suggest that consideration should be given to raising the currently accepted EGRAC threshold for deficiency. This trial was registered at controlled-trials.com as ISRCTN35811298.

Fish consumption and markers of colorectal cancer risk: a multicenter randomized controlled trial.

BACKGROUND: Diet is a major factor in the etiology of colorectal cancer, with high fish consumption possibly decreasing colorectal cancer risk, as was shown in several observational studies. To date, no intervention trials have examined the possible beneficial effects of fish intake on colorectal cancer risk. OBJECTIVE: The objective was to investigate the effects of a 6-mo intervention with oil-rich or lean fish on apoptosis and mitosis within the colonic crypt. DESIGN: In a multicenter, randomized, controlled intervention trial, patients with colorectal polyps, inactive ulcerative colitis, or no macroscopic signs of disease were recruited (n = 242) and randomly allocated to receive dietary advice plus either 300 g oil-rich fish (salmon) per week (n = 82), 300 g lean fish (cod) per week (n = 78), or only dietary advice (DA) (n = 82). Apoptosis and mitosis were measured in colonic biopsy samples collected before and after intervention (n = 213). RESULTS: The total number of apoptotic cells per crypt did not increase in the salmon or cod group: -0.10 (95% CI: -0.36, 0.16) and -0.06 (95% CI: -0.32, 0.20), respectively, compared with the DA group. The total number of mitotic cells per crypt decreased nonsignificantly in the salmon group (-0.87; 95% CI: -2.41, 0.68) and in the cod group (-1.04; 95% CI: -2.62, 0.53) compared with the DA group. Furthermore, the distribution of mitosis within the crypt did not significantly change in either group. CONCLUSION: An increase in the consumption of either oil-rich or lean fish to 2 portions weekly over 6 mo does not markedly change apoptotic and mitotic rates in the colonic mucosa. This trial was registered at www.clinicaltrials.gov as NCT00145015.

Sodium and bone health: impact of moderately high and low salt intakes on calcium metabolism in postmenopausal women.

High salt intake is a well-recognized risk factor for osteoporosis because it induces calciuria, but the effects of salt on calcium metabolism and the potential impact on bone health in postmenopausal women have not been fully characterized. This study investigated adaptive mechanisms in response to changes in salt and calcium intake in postmenopausal women. Eleven women completed a randomized cross-over trial consisting of four successive 5-wk periods of controlled dietary intervention, each separated by a minimum 4-wk washout. Moderately low and high calcium (518 versus 1284 mg) and salt (3.9 versus 11.2 g) diets, reflecting lower and upper intakes in postmenopausal women consuming a Western-style diet, were provided. Stable isotope labeling techniques were used to measure calcium absorption and excretion, compartmental modeling was undertaken to estimate bone calcium balance, and biomarkers of bone formation and resorption were measured in blood and urine. Moderately high salt intake (11.2 g/d) elicited a significant increase in urinary calcium excretion (p = 0.0008) and significantly affected bone calcium balance with the high calcium diet (p = 0.024). Efficiency of calcium absorption was higher after a period of moderately low calcium intake (p < 0.05) but was unaffected by salt intake. Salt was responsible for a significant change in bone calcium balance, from positive to negative, when consumed as part of a high calcium diet, but with a low calcium intake, the bone calcium balance was negative on both high and low salt diets.

Adaptive responses in men fed low- and high-copper diets.

The study of Cu metabolism is hampered by a lack of sensitive and specific biomarkers of status and suitable isotopic labels, but limited information suggests that Cu homeostasis is maintained through changes in absorption and endogenous loss. The aim of the present study was to employ stable-isotope techniques to measure Cu absorption and endogenous losses in adult men adapted to low, moderate and high Cu-supplemented diets. Twelve healthy men, aged 20-59 years, were given diets containing 0.7, 1.6 and 6.0 mg Cu/d for 8 weeks, with at least 4 weeks intervening washout periods. After 6 weeks adaptation, apparent and true absorption of Cu were determined by measuring luminal loss and endogenous excretion of Cu following oral administration of 3 mg highly enriched (65)Cu stable-isotope label. Apparent and true absorption (41 and 48 % respectively) on the low-Cu diet were not significantly different from the high-Cu diet (45 and 48 % respectively). Endogenous losses were significantly reduced on the low- (0.45 mg/d; P<0.001) and medium- (0.81 mg/d; P=0.001) compared with the high-Cu diet (2.46 mg/d). No biochemical changes resulting from the dietary intervention were observed. Cu homeostasis was maintained over a wide range of intake and more rapidly at the lower intake, mainly through changes in endogenous excretion.

Holmium as a faecal marker for copper absorption studies in adults.

The objective of the present study was to investigate the validity of using holmium as a faecal marker in a copper absorption study using a highly enriched (65)Cu stable isotope label. Ten volunteers (nine female, one male) aged 24-55 years were recruited from the Norwich area to take part in a free-living study. The study was conducted in the Human Nutrition Unit at the Institute of Food Research, Norwich, U.K., and involved feeding breakfast test meals containing foods labelled intrinsically or extrinsically with a highly enriched (65)Cu stable isotope label. A 1 mg oral dose of the rare earth element holmium was administered to volunteers simultaneously with an oral dose of highly enriched (65)Cu stable isotope as a label in the breakfast test meal. Complete faecal collections were made for 10 days after dosing, and the mean percentage holmium recovery (+/- S.D.) was 105 +/- 15%. After correcting for re-excreted copper label, the labelled copper and holmium had similar excretory profiles. It was concluded that holmium is a valid faecal marker in adult human copper absorption studies using stable isotopes.