PubMed Health⌕ Search

Biomedical subjects

Paul Elliott

Publications and source records attributed to Paul Elliott.

At least 19 recordsLinked to original sources

Early growth and adult respiratory function in men and women followed from the fetal period to adulthood.

BACKGROUND: While some studies suggest that poor fetal growth rate, as indicated by lower birth weight, is associated with poor respiratory function in childhood, findings among adults remain inconsistent. A study was undertaken to determine the association between early growth and adult respiratory function. METHODS: A longitudinal birth cohort study was performed of 5390 men and women born full term and prospectively followed from the fetal period to adulthood. Weight at birth and infancy were recorded, and forced expiratory volume in 1 s (FEV(1)) and forced vital capacity (FVC) were assessed by standard spirometry at age 31 years. RESULTS: Adult FEV(1) and FVC increased linearly with higher birth weight in both men and women with no apparent threshold. After adjustment for sex, adult height and other potential confounders operating through the life course, every 500 g higher birth weight was associated with a higher FEV(1) of 53.1 ml (95% CI 38.4 to 67.7) and higher FVC of 52.5 ml (95% CI 35.5 to 69.4). These positive associations persisted across categories of smoking, physical activity and body mass index, with the lowest respiratory function noted among those with lower birth weight who were smokers, led a sedentary lifestyle or were overweight. Weight gain in infancy was also positively associated with adult lung function. CONCLUSION: Birth weight is continuously and independently associated with adult respiratory function. It is plausible that poor growth in early life may restrict normal lung growth and development, which could have long-term consequences on lung function later in life.

Adult↗

Kidney disease mortality and environmental exposure to mercury.

Runcorn, North West England, has been a site of industrial activity for over 100 years. Preliminary investigations have revealed excess risk of renal mortality in the population living closest to several sources of pollution. Exposure to airborne mercury has been highlighted as a possible cause, although there is also concomitant exposure to solvents and other heavy metals in this population. The authors used validated air dispersion modeling to identify mercury-exposed populations. Standardized mortality ratios for kidney disease were computed using the North West government region as the reference. There was a significant exposure-response relation between modeled estimates of mercury exposure and risk of kidney disease mortality (test for trend: p = 0.02 for men and p = 0.03 for women), and this relation was more pronounced for estimated historical exposure (test for trend: p = 0.01 for men and p < 0.001 for women). These findings suggest that exposure to mercury is a possible cause of the excess kidney disease mortality in this population, indicating that there might still be a health legacy of the historically high levels of industrial activity in the Runcorn area.

Adult↗

Call-related factors influencing output power from mobile phones.

Mobile phone use is increasing but there is also concern for adverse health effects. Well-designed prospective studies to assess several health outcomes are required. In designing a study of mobile phone use, it is important to assess which factors need to be considered in classifying the exposure to radiofrequency fields (RF). A pilot study was performed in Sweden and in the UK 2002 to 2003 to test the feasibility of recruiting a cohort of mobile phone users from a random population sample and from mobile phone subscription lists for a prospective study. As one part of this pilot study, different factors were evaluated regarding possible influence on the output power of the phones. By local switch logging, information on calls made from predefined subscriptions or dedicated handsets were obtained and the output power of phones during calls made indoors and outdoors, in moving and stationary mode, and in rural as well in urban areas were compared. In this experiment, calls were either 1, 1.5 or 5 min long. The results showed that high mobile phone output power is more frequent in rural areas whereas the other factors (length of call, moving/stationary, indoor/outdoor) were of less importance. Urban and rural area should be considered in an exposure index for classification of the exposure to RF from mobile phones and may be assessed by first base station during mobile phone calls or, if this information is not available, possibly by using home address as a proxy.

Cell Phone↗

Assessment of analytical reproducibility of 1H NMR spectroscopy based metabonomics for large-scale epidemiological research: the INTERMAP Study.

Large-scale population phenotyping for molecular epidemiological studies is subject to all the usual criteria of analytical chemistry. As part of a major phenotyping investigation we have used high-resolution 1H NMR spectroscopy to characterize 24-h urine specimens obtained from population samples in Aito Town, Japan (n = 259), Chicago, IL (n = 315), and Guangxi, China (n = 278). We have investigated analytical reproducibility, urine specimen storage procedures, interinstrument variability, and split specimen detection. Our data show that the multivariate analytical reproducibility of the NMR screening platform was >98% and that most classification errors were due to urine specimen handling inhomogeneity. Differences in metabolite profiles were then assessed for Aito Town, Chicago, and Guangxi population samples; novel combinations of biomarkers were detected that separated the population samples. These cross-population differences in urinary metabolites could be related to genetic, dietary, and gut microbial factors.

Biomarkers↗

Microencapsulated BioBullets for the control of biofouling zebra mussels.

The widespread invasion of freshwaters by the zebra mussel, Dreissena polymorpha, during the last 2 decades has made it one of the world's most economically and ecologically important pests. Since arriving in the North American Great Lakes in the 1980s, zebra mussels have become a major biofouler, blocking the raw water cooling systems of power stations and water treatment works and costing U.S. dollars 1-5 billion per year. Despite the development of numerous control methods, chlorination remains the only widespread and licensed technique. Zebra mussels are able to sense chlorine and othertoxins in their surrounding environment and respond by closing their valves, thus enabling them to avoid toxic effects for up to 3 weeks. Furthermore, prolonged dosing of chlorine in raw water produces ecotoxic trihalomethanes (THMs) by reaction with organic material in the water. We have developed a novel, environmentally safe, and effective method for controlling the zebra mussel: the BioBullet. Our method uses the encapsulation of an active ingredient (KCI) in microscopic particles of edible material. The mussels' natural filtering ability then removes and concentrates the particles from the water, without stimulating the valve-closing response. By using the mussels' filtering behavior to concentrate BioBullets the absolute quantity of active ingredient added to the water can be reduced substantially. Our approach allows us to engineer the particles to break up and dissolve completely within a few hours, thus eliminating the risk of polluting the wider ecosystem. We demonstrate that the effectiveness of a toxin in the control of biofouling filter-feeders can be enhanced greatly by using our technique. This paves the way for a new approach to the control of some of the world's most important economic pests.

Animals↗

Association between protein intake and blood pressure: the INTERMAP Study.

BACKGROUND: Findings from epidemiological studies suggest an inverse relationship between individuals' protein intake and their blood pressure. METHODS: Cross-sectional epidemiological study of 4680 persons, aged 40 to 59 years, from 4 countries. Systolic and diastolic blood pressure was measured 8 times at 4 visits. Dietary intake based on 24-hour dietary recalls was recorded 4 times. Information on dietary supplements was noted. Two 24-hour urine samples were obtained per person. RESULTS: There was a significant inverse relationship between vegetable protein intake and blood pressure. After adjusting for confounders, blood pressure differences associated with higher vegetable protein intake of 2.8% kilocalories were -2.14 mm Hg systolic and -1.35 mm Hg diastolic (P<.001 for both); after further adjustment for height and weight, these differences were -1.11 mm Hg systolic (P<.01) and -0.71 mm Hg diastolic (P<.05). For animal protein intake, significant positive blood pressure differences did not persist after adjusting for height and weight. For total protein intake (which had a significant interaction with sex), there was no significant association with blood pressure in women, nor in men after adjusting for dietary confounders. There were significant differences in the amino acid content of the diets of persons with high vegetable and low animal protein intake vs the diets of persons with low vegetable and high animal protein intake. CONCLUSIONS: Vegetable protein intake was inversely related to blood pressure. This finding is consistent with recommendations that a diet high in vegetable products be part of healthy lifestyle for prevention of high blood pressure and related diseases.

Adult↗

Meta-analysis of studies of alcohol and breast cancer with consideration of the methodological issues.

OBJECTIVE: To give an up-to-date assessment of the association of alcohol with female breast cancer, addressing methodological issues and shortfalls in previous overviews. METHODS: Meta-analysis of studies (any language) providing original data on incidence of first primary breast cancer and alcohol. Two reviewers independently extracted data. Study quality assessed by objective criteria including degree of control for confounding; funnel plots examined for publication bias; meta-regression techniques to explore heterogeneity. Risks associated with drinking versus not drinking and dose-response not constrained through the origin estimated using random effects methods. RESULTS: Ninety-eight unique studies were included, involving 75,728 and 60,653 cases in drinker versus non-drinker and dose-response analyses, respectively. Findings were robust to study design and analytic approaches in the meta-analyses. For studies judged high quality, controlled for appropriate confounders, excess risk associated with alcohol drinking was 22% (95% CI: 9-37%); each additional 10 g ethanol/day was associated with risk higher by 10% (95% CI: 5-15%). There was no evidence of publication bias. Risk did not differ significantly by beverage type or menopausal status. Estimated population attributable risks were 1.6 and 6.0% in USA and UK, respectively. CONCLUSIONS: Taking account of shortcomings in the study base and methodological concerns, we confirm the alcohol-breast cancer association. We compared our results to those of an individual patient data analysis, with similar findings. We conclude that the association between alcohol and breast cancer may be causal.

Alcohol Drinking↗

Assessment of uncertainty in a probabilistic model of consumer exposure to pesticide residues in food.

The assessment of consumer exposure to pesticides is an important part of pesticide regulation. Probabilistic modelling allows analysis of uncertainty and variability in risk assessments. The output of any assessment will be influenced by the characteristics and uncertainty of the inputs, model structure and assumptions. While the use of probabilistic models is well established in the United States, in Europe problems of low acceptance, sparse data and lack of guidelines are slowing the development. The analyses in the current paper focused on the dietary pathway and the exposure of UK toddlers. Three single food, single pesticide case studies were used to parameterize a simple probabilistic model built in Crystal Ball. Data on dietary consumption patterns were extracted from National Diet and Nutrition Surveys, and levels of pesticide active ingredients in foods were collected from Pesticide Residues Committee monitoring. The effect of uncertainty on the exposure estimate was analysed using scenarios, reflecting different assumptions related to sources of uncertainty. The most influential uncertainty issue was the distribution type used to represent input variables. Other sources that most affected model output were non-detects, unit-to-unit variability and processing. Specifying correlation between variables was found to have little effect on exposure estimates. The findings have important implications for how probabilistic modelling should be conducted, communicated and used by policy and decision makers as part of consumer risk assessment of pesticides.

Body Weight↗

Blood pressure and the global burden of disease 2000. Part 1: estimates of blood pressure levels.

OBJECTIVE: To provide global estimates of blood pressure by age and sex for adults aged > or = 30 years, by WHO subregion. DESIGN AND METHODS: Data were obtained from studies identified in a literature review of population-based surveys. These were complemented by data from MONICA and INTERSALT studies. Estimates of the shape of the age-systolic blood pressure (SBP) association were made from survey data utilizing parametric and non-parametric analyses. A linear sex-specific association of SBP with age was demonstrated from 30 to 70 years in females and 20 to 70 years for males in each subregion. Mean age- and sex-specific estimates of SBP were estimated for each WHO subregion separately, based on study and country-weighted SBP data. RESULTS: Analyses were based on data from about 230 surveys and over 660 000 participants. Age-specific mean SBP values ranged from 114 to 164 mmHg for females, and 117-153 mmHg for males. Females typically had lower SBP levels than males in the 30-44-year age groups, but in all subregions, SBP levels rose more steeply with age for females than males. Therefore, SBP levels in those aged > or = 60 years tended to be higher in females. Subregions with consistently high mean SBP levels included parts of eastern Europe and Africa. Mean SBP levels were lowest in south-east Asia and parts of the western Pacific. CONCLUSIONS: These global estimates of blood pressure by age, sex and subregion show considerable variation in estimated levels. The lack of data in developing countries is substantial, and this is an important limitation given the role of blood pressure in increasing cardiovascular disease levels.

Adult↗

Blood pressure and the global burden of disease 2000. Part II: estimates of attributable burden.

OBJECTIVES: To provide estimates of the global burden of disease attributable to non-optimal blood pressure by age and sex for adults aged > or = 30 years, by WHO subregion. METHODS: Estimates of attributable burden were made using population impact fractions, which used data on mean systolic blood pressure levels, disease burden [in deaths and/or disability-adjusted life years (DALYs)] and relative risk corrected for regression dilution bias. Estimates were made of burden attributable to a population distribution of blood pressure with a mean systolic blood pressure of greater than 115 mmHg. RESULTS: Globally, approximately two-thirds of stroke and one-half of ischaemic heart disease were attributable to non-optimal blood pressure. These proportions were highest in the more developed parts of the world. Worldwide, 7.1 million deaths (approximately 12.8% of the global total) and 64.3 million DALYs (4.4% of the global total) were estimated to be due to non-optimal blood pressure. Overall approximately, two-thirds of the attributable burden of disease occurred in the developing world, approximately two-thirds in the middle age groups (45-69 years) and approximately one-half occurred in those with systolic blood pressure levels between 130 and 150 mmHg. CONCLUSIONS: The burden of non-optimal blood pressure is almost double that of the only previous global estimates, which is largely explained by the correction for regression dilution adopted in these analyses. High blood pressure is a leading cause of global burden of disease, and most of it occurs in the developing world.

Blood Pressure↗

Hemoglobin concentration in pregnancy and perinatal mortality: a London-based cohort study.

OBJECTIVE: Failure of fetal growth during pregnancy, and preterm birth, are the major causes of stillbirth and early neonatal death. The objective of the study was to determine the association between maternal hemoglobin concentration during pregnancy and perinatal mortality. STUDY DESIGN: The design was prospective, using data on 222,614 first singleton pregnancies in the St Mary's Maternity Information System database in the Northwest Thames region of London. RESULTS: The association of perinatal mortality with maternal hemoglobin at first antenatal check was not statistically significant (P>.10), but a statistically significant (P<.001) U-shaped pattern was found with lowest recorded maternal hemoglobin concentration. Both early neonatal mortality and stillbirth rates were statistically significantly (P<.005) associated with lowest maternal hemoglobin concentration. The relationship of lowest hemoglobin with early neonatal mortality was largely mediated by the effect of preterm birth, and that between lowest hemoglobin and stillbirth by fetal growth restriction. The lowest perinatal mortality was associated with a lowest recorded maternal hemoglobin concentration of between 9-11 g/dL. CONCLUSION: There is an optimal range of lowest hemoglobin concentration in pregnancy, and on either side of this perinatal mortality is increased. The effect of lowest hemoglobin is largely mediated through associations with preterm birth and fetal growth restriction.

Birth Weight↗

Modelling exposure to disinfection by-products in drinking water for an epidemiological study of adverse birth outcomes.

We are conducting an epidemiological study on the association between disinfection by-product concentrations in drinking water and adverse birth outcomes in the UK, using trihalomethane (THM) concentrations over defined water zones as an exposure index. Here we construct statistical models using sparse routinely collected THMs measurements to obtain quarterly estimates of mean THM concentrations for each water zone. We modelled the THM measurements using a Bayesian hierarchical mixture model, taking into account heterogeneity in THM concentrations between water originating from different source types, quarterly variation in THM concentrations and uncertainty in the true value of undetected and rounded measurements. Quarterly estimates of mean THM concentrations plus estimates of the water source type (ground, lowland surface or upland surface) were obtained for each water zone. THM concentration estimates were typically highest from July to September (third quarter), and varied considerably between water sources. Our exposure estimates were categorized into 'low', 'medium' and 'high' THM classes. Our modelled quarterly exposure estimates were compared to a simple alternative: annual means of the raw data for each water zone. In all, 15-25% of exposure estimates were classified differently. The modelled THM estimates led to slightly stronger and more precise estimates of association with risk of still birth and low birth weight than did the raw annual means. We conclude that our modelling approach enabled us to provide robust quarterly estimates of ecological exposure to THMs in a situation where the raw data were too sparse to base exposure assessment on empirical summaries alone.

Adult↗

Relation of nutrient intake to microalbuminuria in nondiabetic middle-aged men and women: International Population Study on Macronutrients and Blood Pressure (INTERMAP).

BACKGROUND: Microalbuminuria (MA) is a risk factor for cardiovascular and renal disease. However, little is known about the relation of nutritional factors to MA, especially in individuals without diabetes. METHODS: Data collected by the International Population Study on Macronutrients and Blood Pressure from 1997 to 1999 were used to assess relations of multiple dietary factors (energy intake, macronutrients, and micronutrients) independent of lifestyle-related cardiovascular risk factors to MA (urinary albumin excretion, 30 to <300 mg/24 h). The study population included 4,381 Chinese, Japanese, UK, and US men and women without diabetes aged 40 to 59 years (17 population samples) without macroalbuminuria. RESULTS: MA prevalences ranged from 3.1% to 5.5% for men and 2.6% to 4.6% for women in the 4 countries. With adjustment for age and country, the following nutrients considered singly (of 29) were related in logistic regression analyses to MA prevalence ( P < 0.05): for men, inversely, iron, vitamin C and E, estimated total simple sugar, omega-6 fatty acid, polyunsaturated fatty acid, and calcium (all expressed as caloric density) intake; for women, directly, 24-hour urinary sodium excretion and alcohol intake. In multivariate analyses, sugar, iron, polyunsaturated fats, and vitamin C and E intake (in men) and alcohol intake (women only) remained associated with MA ( P < 0.05). MA also was related directly to body mass index ( P < 0.05), blood pressure ( P < 0.001), and smoking ( P > 0.05) and inversely to education ( P < 0.05 in women). CONCLUSION: In cross-sectional analyses, several nutrients were related to MA among men. Additional studies are required to confirm these findings.

Adult↗

Attainment of precision in implementation of 24 h dietary recalls: INTERMAP UK.

Collection of complete and accurate dietary intake data is necessary to investigate the association of nutrient intakes with disease outcomes. A standardised multiple-pass 24 h dietary recall method was used in the International Collaborative Study of Macro- and Micronutrients and Blood Pressure (INTERMAP) to obtain maximally objective data. Dietary interviewers were intensively trained and recalls taped, with consent, for randomly selected evaluations by the local site nutritionist (SN) and/or country nutritionists (CN) using a twelve-criterion checklist marked on a four-point scale (1, retrain, to 4, excellent). In the Belfast centre, seven dietary interviewers collected 932 24 h recalls from 40-59-year-old men and women. Total scores from the 134 evaluated recalls ranged from thirty-four to the maximum forty-eight points. All twelve aspects of the interviews were completed satisfactorily on average whether scored by the SN (n 53, range: probing 3.25 to privacy of interview 3.98) or CN (n 19, range: probing 3.26 to pace of interview and general manner of interviewer 3.95); the CN gave significantly lower scores than the SN for recalls evaluated by both nutritionists (n 31, Wilcoxon signed rank test, P=0.001). Five evaluations of three recalls identified areas requiring retraining or work to improve performance. Reporting accuracy was estimated using BMR; energy intake estimates less than 1.2 x BMR identifying under-reporting. Mean ratios in all age, sex and body-mass groups were above this cut-off point; overall, 26.1 % were below. Experiences from the INTERMAP Belfast centre indicate that difficulties in collection of dietary information can be anticipated and contained by the systematic use of methods to prevent, detect and correct errors.

Blood Pressure↗

Relation of trihalomethane concentrations in public water supplies to stillbirth and birth weight in three water regions in England.

We investigated the association between total trihalomethanes (TTHMs) and risk of stillbirth and low and very low birth weight in three water regions in England, 1992-1998; associations with individual trihalomethanes (THMs) were also examined. Modeled estimates of quarterly TTHM concentrations in water zones, categorized as low (< 30 microg/L), medium (30-59 microg/L), or high (> or = 60 microg/L), were linked to approximately 1 million routine birth and stillbirth records using maternal residence at time of birth. In one region, where there was a positive socioeconomic deprivation gradient across exposure categories, there was also a positive, significant association of TTHM with risk of stillbirth and low and very low birth weight. Overall summary estimates across the three regions using a random-effects model to allow for between-region heterogeneity in exposure effects showed small excess risks in areas with high TTHM concentrations for stillbirths [odds ratio (OR) = 1.11; 95% confidence interval (CI), 1.00-1.23), low birth weight (OR = 1.09; 95% CI, 0.93-1.27), and very low birth weight (OR = 1.05; 95% CI, 0.82-1.34). Among the individual THMs, chloroform showed a similar pattern of risk as TTHM, but no association was found with concentrations of bromodichloromethane or total brominated THMs. Our findings overall suggest a significant association of stillbirths with maternal residence in areas with high TTHM exposure. Further work is needed looking at cause-specific stillbirths and effects of other disinfection by-products and to help differentiate between alternative (noncausal) explanations and those that may derive from the water supply.

Adult↗

Evaluation of measures of urinary albumin excretion in epidemiologic studies.

Twenty-four-hour urinary albumin excretion (UAE) is considered the gold standard for determining albumin level in epidemiologic studies, but this measure is inconvenient and often unavailable. Simpler alternatives include the albumin:creatinine ratio (ACR) and urinary albumin concentration (UAC) obtained from a single sample. The authors assessed the strengths and weaknesses of ACR and UAC as alternatives to UAE using albumin measurements from two 24-hour urine samples collected in 1996-1999 from 4,678 participants aged 40-59 years in the International Study of Macronutrients and Blood Pressure (17 population samples from four countries). The authors compared ACR and UAC with regard to correlations with UAE, daily within-person variability, and associations with known predictors of UAE. Rank-order correlations of ACR with UAE were 0.949 and 0.942 for men and women, respectively, versus 0.881 and 0.816 for UAC. Mean within-person coefficients of variation were 34.0-40.0% for the three measures, with the smallest values being observed for UAC. Average correlations with blood pressure were similar for UAE, ACR, and UAC, but the correlation with body mass index was lower for ACR (0.118 for ACR and 0.188 for UAC vs. 0.211 for UAE) because of high correlation between body mass index and creatinine level. Thus, UAC and ACR are acceptable alternatives to the more complex UAE, and the simpler UAC may be preferable to ACR in some respects.

Adult↗

Maternal blood pressure in pregnancy, birth weight, and perinatal mortality in first births: prospective study.

OBJECTIVE: To investigate the relation of diastolic blood pressure in pregnancy with birth weight and perinatal mortality. DESIGN: Prospective study. SETTING: 15 maternity units in one London health region, 1988-2000. PARTICIPANTS: 210 814 first singleton births of babies weighing more than 200 g among mothers with no hypertension before 20 weeks' gestation and without proteinuria, delivering between 24 and 43 weeks' gestation. MAIN OUTCOME MEASURES: Birth weight and perinatal mortality. RESULTS: The mean (SD) birth weight of babies born to mothers with no hypertension before 20 weeks' gestation or proteinuria was 3282 g (545 g) and there were 1335 perinatal deaths, compared with 94 perinatal deaths among women with proteinuria or a history of hypertension. Diastolic blood pressure at booking for antenatal checks was progressively higher from weeks 34 to 40 of gestation. The birth weight of babies being delivered after 34 weeks was highest for highest recorded maternal diastolic blood pressures of between 70 and 80 mm Hg and lower for blood pressures outside this range. Both low and high diastolic blood pressures were associated with statistically significantly higher perinatal mortality. Using a linear quadratic model, 94 of 825 (11.4%) perinatal deaths could be attributed to mothers having blood pressure differing from the optimal blood pressure (82.7 mm Hg) predicted by the fitted model. Most of these excess deaths occurred with blood pressures below the optimal value. CONCLUSIONS: Both low and high diastolic blood pressures in women during pregnancy are associated with small babies and high perinatal mortality.

Adolescent↗

Early life factors and blood pressure at age 31 years in the 1966 northern Finland birth cohort.

Data on the birth weight-blood pressure relationship are inconsistent. Although an inverse association has been suggested in several large studies, interpretation is complicated by publication and other biases. Few data are available on the relationship between other early growth measures and blood pressure. We examined the shape and size of association between determinants of fetal growth, size at birth, growth in infancy, and adult systolic and diastolic blood pressure at 31 years in the prospective northern Finnish 1966 birth cohort of 5960 participants. Birth weight, birth length, gestational age, ponderal index, and birth weight relative to gestational age showed a significant inverse association with blood pressure at age 31. Rapid growth in infancy ("change-up") was positively associated with blood pressure. Adjusted regression coefficients for birth weight indicated systolic/diastolic blood pressure lower by -1.7 (95% confidence interval [CI], -2.5, -1.0)/-0.7 (95% CI, -1.4, -0.02) mm Hg for 1 kg higher birth weight. The significant inverse association between birth weight and systolic blood pressure persisted without adjustment for adult body mass index for males. Among females, gestational age showed a stronger association with blood pressure than birth weight: gestational age higher by 7 weeks (equivalent to an average of 1 kg higher birth weight) among singletons associated with -2.9 (95% CI, -4.7, -1.1) mm Hg lower systolic blood pressure. Our results support the concept that birth weight, other birth measures, and infant growth are important determinants of blood pressure and hence cardiovascular disease risk in later life.

Adolescent↗