Alan A Jackson

NIHR Oxford Biomedical Research, Oxford, England, United Kingdom

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Publications (59)175.24 Total impact

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    ABSTRACT: During pregnancy, adult women with a normal BMI synthesise extra amino acids after an overnight fast by increasing body protein breakdown and decreasing amino acid oxidation. It is not known whether adolescent girls can make these adaptations during pregnancy. The present study aimed to measure and compare the protein, glutamine and alanine kinetics of adult women and adolescent girls at early-, mid- and late-pregnancy. Kinetics were measured in the overnight fasted state using intravenous infusions of 13C-leucine, 15N-glutamine and 15N-alanine in ten adults and twenty adolescents aged 14-17 years in the first and second trimesters (phase 1 study) and infusions of 13C-leucine and 15N2-urea in ten adults and eleven adolescents aged 16-17 years in the first and third trimesters (phase 2 study). In phase 1 study, there were no significant differences between the groups with regard to any of the kinetic parameters measured. In both groups, leucine flux increased (P< 0·05), the percentage of leucine flux oxidised decreased (P< 0·05) and non-oxidative leucine disposal to protein synthesis increased (P< 0·05) from the first to the second trimester. In phase2 study, leucine flux was significantly slower (P< 0·05) in the adult group than in the adolescent group during both trimesters, and whole-body leucine flux and non-oxidative leucine disposal increased significantly in the adolescent group (P< 0·05, respectively) and were higher in the adult group from the first to the third trimester. These results suggest that similar to their adult counterparts after an overnight fast, adolescent girls with a normal BMI synthesise extra amino acids required for net protein deposition during pregnancy by increasing protein breakdown and decreasing amino acid oxidation.
    The British journal of nutrition. 10/2014;
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    ABSTRACT: Background Malnutrition is common amongst hospitalised older patients and associated with increased morbidity and mortality. Poor dietary intake results from factors including acute illness and cognitive impairment but additionally patients may have difficulty managing at mealtimes. Use of volunteers to help at mealtimes is rarely evaluated.Objectives To obtain multiple perspectives on nutritional care of older inpatients, acceptability of trained volunteers and identify important elements of their assistance.DesignA qualitative study 1 year before and after introduction of volunteer mealtime assistants on one ward and parallel comparison with a control ward in a Medicine for Older People department at a UK university hospital.Participants and methodsSemi-structured interviews and focus groups, in baseline and intervention years, with purposively sampled nursing staff at different levels of seniority; patients or close relatives; and volunteers.ResultsAt baseline staff felt under pressure with insufficient people assisting at mealtimes. Introducing trained volunteers was perceived by staff and patients to improve quality of mealtime care by preparing patients for mealtimes, assisting patients who needed help, and releasing nursing time to assist dysphagic or drowsy patients. There was synergy with other initiatives, notably protected mealtimes. Interviews highlighted the perceived contribution of chronic poor appetite and changes in eating patterns to risk of malnutrition.Conclusions Improved quality of mealtime care attributed to volunteers’ input has potential to enhance staff morale and patients’/relatives’ confidence. A volunteer mealtime assistance scheme may work best when introduced in context of other changes reflecting commitment to improving nutrition.Implications for practice(i) A mealtime assistance scheme should incorporate training, supervision and support for volunteers; (ii) Good relationships and a sense of teamwork can develop between wards staff and volunteers; (iii) Impact may be maximised in the context of ‘protected mealtimes’.
    International Journal of Older People Nursing 08/2014;
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    ABSTRACT: To determine the feasibility and acceptability of using trained volunteers as mealtime assistants for older hospital inpatients. Poor nutrition among hospitalised older patients is common in many countries and associated with poor outcomes. Competing time pressures on nursing staff may make it difficult to prioritise mealtime assistance especially on wards where many patients need help. Mixed methods evaluation of the introduction of trained volunteer mealtime assistants on an acute female medicine for older people ward in a teaching hospital in England. A training programme was developed for volunteers who assisted female inpatients aged 70 years and over on weekday lunchtimes. The feasibility of using volunteers was determined by the proportion recruited, trained, and their activity and retention over one year. The acceptability of the training and of the volunteers' role was obtained through interviews and focus groups with 12 volunteers, nine patients and 17 nursing staff. Fifty-nine potential volunteers were identified: 38 attended a training session, of whom 29 delivered mealtime assistance, including feeding, to 3911 (76%) ward patients during the year (mean duration of assistance 5·5 months). The volunteers were positive about the practical aspects of training and ongoing support provided. They were highly valued by patients and ward staff and have continued to volunteer. Volunteers can be recruited and trained to help acutely unwell older female inpatients at mealtimes, including feeding. This assistance is sustainable and is valued. This paper describes a successful method for recruitment, training and retention of volunteer mealtime assistants. It includes a profile of those volunteers who provided the most assistance, details of the training programme and role of the volunteers and could be replicated by nursing staff in other healthcare units.
    Journal of Clinical Nursing 03/2014; · 1.32 Impact Factor
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    Archives of Disease in Childhood 11/2013; · 3.05 Impact Factor
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    ABSTRACT: This study determined the rates of (13)C-aminopyrine metabolism in patients with varying degrees of liver cirrhosis as defined by clinical scores. Twenty-five cirrhotic patients and 18 healthy subjects underwent a (13)C-aminopyrine breath test. The cumulative per cent dose recovery (cPDR) of (13)C on breath expressed as a percentage of the administered dose at 2 h was significantly lower in cirrhotic patients than in healthy subjects (median: 1.7% versus 9.0%; p<.0001). Significant inverse associations between cPDR at 2 h and the model for end-stage liver disease score, Child-Pugh score, international normalised ratio and bilirubin (all p<.05), but not alanine aminotransferase or alkaline phosphatase were observed in the cirrhotic patients. Taking each biochemical marker independently, cirrhotic patients with normal biochemistry had a significantly lower cPDR at 2 h than healthy subjects (all p<.05). Differences in (13)C-aminopyrine metabolism were evident in cirrhotic patients with less severe disease and may mark hepatic dysfunction when conventional biochemical markers appear unchanged.
    Isotopes in Environmental and Health Studies 06/2013; · 0.70 Impact Factor
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    ABSTRACT: BACKGROUND: Malnutrition is common in older people in hospital and is associated with adverse clinical outcomes including increased mortality, morbidity and length of stay. This has raised concerns about the nutrition and diet of hospital in-patients. A number of factors may contribute to low dietary intakes in hospital, including acute illness and cognitive impairment among in-patients. The extent to which other factors influence intake such as a lack of help at mealtimes, for patients who require assistance with eating, is uncertain. This study aims to evaluate the effectiveness of using trained volunteer mealtime assistants to help patients on an acute medical ward for older people at mealtimes.Methods/designThe study design is quasi-experimental with a before (year one) and after (year two) comparison of patients on the intervention ward and parallel comparison with patients on a control ward in the same department. The intervention in the second year was the provision of trained volunteer mealtime assistance to patients in the intervention ward. There were three components of data collection that were repeated in both years on both wards. The first (primary) outcome was patients' dietary intake, collected as individual patient records and as ward-level balance data over 24 hour periods. The second was clinical outcome data assessed on admission and discharge from both wards, and 6 and 12 months after discharge. Finally qualitative data on the views and experience of patients, carers, staff and volunteers was collected through interviews and focus groups in both years to allow a mixed-method evaluation of the intervention. DISCUSSION: The study will describe the effect of provision of trained volunteer mealtime assistants on the dietary intake of older medical in-patients. The association between dietary intake and clinical outcomes including malnutrition risk, body composition, grip strength, length of hospital stay and mortality will also be determined. An important component of the study is the use of qualitative approaches to determine the views of patients, relatives, staff and volunteers on nutrition in hospital and the impact of mealtime assistance.Trial registrationTrial registered with ClinicalTrials.gov NCTO1647204.
    BMC Geriatrics 01/2013; 13(1):5. · 2.34 Impact Factor
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    ABSTRACT: Infants born preterm are significantly lighter and shorter on reaching term equivalent age (TEA) than are those born at term, but the relation with body composition is less clear. We conducted a systematic review to assess the body composition at TEA of infants born preterm. The databases MEDLINE, Embase, CINAHL, HMIC, "Web of Science," and "CSA Conference Papers Index" were searched between 1947 and June 2011, with selective citation and reference searching. Included studies had to have directly compared measures of body composition at TEA in preterm infants and infants born full-term. Data on body composition, anthropometry, and birth details were extracted from each article. Eight studies (733 infants) fulfilled the inclusion criteria. Mean gestational age and weight at birth were 30.0 weeks and 1.18 kg in the preterm group and 39.6 weeks and 3.41 kg in the term group, respectively. Meta-analysis showed that the preterm infants had a greater percentage total body fat at TEA than those born full-term (mean difference, 3%; P = .03), less fat mass (mean difference, 50 g; P = .03), and much less fat-free mass (mean difference, 460 g; P < .0001). The body composition at TEA of infants born preterm is different than that of infants born at term. Preterm infants have less lean tissue but more similar fat mass. There is a need to determine whether improved nutritional management can enhance lean tissue acquisition, which indicates a need for measures of body composition in addition to routine anthropometry.
    PEDIATRICS 08/2012; 130(3):e640-9. · 4.47 Impact Factor
  • D Joe Millward, Alan A Jackson
    American Journal of Clinical Nutrition 06/2012; 95(6):1498-501; author reply 1501-2. · 6.50 Impact Factor
  • Alan A Jackson
    American Journal of Clinical Nutrition 11/2011; 94(6):1394-5. · 6.50 Impact Factor
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    ABSTRACT: A 22-year-old man suffered an acute small bowel infarct leading to extensive bowel resection, resulting in only 20 cm of jejunum to a jejunostomy, although he also had 50 cm of residual colon with a mucous fistula. The patient was out on long-term home parenteral nutrition (PN) but endured high stomal losses of 5-6 L per day and, despite all conventional measures, required 6.1 L of fluid (including PN) and 555 mmol sodium per day. Although body mass index was maintained, he suffered debilitating malaise and recurrent episodes of catheter-related sepsis and also developed persistently abnormal liver function tests. He was considered a potential intestinal transplant patient, but before taking that step, he opted for reanastomosis of his residual colon to his jejunum, ending in a colostomy. At surgery, only 30 cm of additional bowel lengthening could be achieved, but despite this, the patient's stomal losses reduced to 2.5 L per day, intravenous fluid requirements reduced to 4.1 L per day, and liver function normalized. The patient also gained 7.5 kg despite no change in PN caloric prescription, and his quality of life was dramatically enhanced. The case illustrates that even a small length of colon can grant significant improvements, probably via improvements in small bowel transit and adaptive changes, better sodium and water resorption with decreased hyperaldosteronism, and enhanced energy and nitrogen recovery. Reanastomosis of defunctioned colon should therefore always be considered a management option in short bowel syndrome.
    Journal of Parenteral and Enteral Nutrition 11/2011; 35(6):732-5. · 2.49 Impact Factor
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    ABSTRACT: This study determined the within-subject and between-subject variability of different ways of expressing the results of the (13)C-aminopyrine breath test ((13)C-ABT) and the effect of shortening the test duration. The (13)C-ABT was conducted on three separate occasions in 10 healthy volunteers and on a single occasion in 22 patients with established liver cirrhosis. The within-subject variability of cumulative percentage dose recovered (cPDR), using measured CO(2) production rate (VCO(2)), in the reference group over three trials was 15% over 120 min. Higher within-subject variability in cPDR would have been evident if the test was terminated at either 30 or 60 min. Substitution of predicted VCO(2) to calculate cPDR yielded comparable values at all time points. Significant differences between cirrhotics and reference group were evident after just 10 min using PDR/h, cPDR or enrichment (all P<0.05). The ABT demonstrates clinically acceptable reproducibility. Shortening of the duration may make the test more acceptable clinically, but it is associated with increasing imprecision.
    Isotopes in Environmental and Health Studies 07/2011; 47(3):390-9. · 0.70 Impact Factor
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    ABSTRACT: Little is known about the impact of disease and treatment on the pattern of growth in children with Inflammatory Bowel Disease (IBD). Significant deficits in height and weight in children with Crohn's disease have been reported but changes in fat and fat free mass are less well defined. This study aims to describe the height, weight and body composition of a cohort of children with IBD. Height, weight, skinfold thicknesses and bioelectrical impedance analysis was performed. Disease activity was assessed with clinical scoring systems. 55 children, median age 13.7 years (range 6.5-17.7) were studied. Median (25th, 75th percentile) Standard Deviation Score for BMI, Height and Weight were - 0.3 (- 0.97, 0.65), - 0.56 (- 1.42, 0.06), - 0.62 (- 1.43, 0.19). In Crohn's disease, using multiple regression analysis disease activity measured by PCDAI was significantly inversely related to fat free mass (β - 0.2, 95% CI -0.17, -0.03, p 0.005). Children with IBD were both under and overweight. Nutritional deficits were more common in Crohn's disease. Fat free mass was related to disease activity in children with Crohn's disease regardless of changes in weight. Weight or BMI may mask deficits in lean tissue in the presence of normal or increased proportions of body fat.
    Clinical nutrition (Edinburgh, Scotland) 02/2011; 30(1):112-5. · 3.27 Impact Factor
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    ABSTRACT: This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae, and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings,
    Isotopes in Environmental and Health Studies 01/2011; 47:390-399. · 0.70 Impact Factor
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    World review of nutrition and dietetics 01/2010; 101:56-72.
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    Journal of Nutrigenetics and Nutrigenomics 01/2010; 3(4-6):192-208. · 1.31 Impact Factor
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    ABSTRACT: The extent to which socio-economic and personal characteristics might interact with zinc and selected antioxidant nutrients to influence serum retinol has been determined in adolescent girls in urban Bangladesh. Two hundred and twenty-five girls, aged between 12 and 15 years, from four girl's high schools participated in the study. Information on their social status was collected by questionnaire and a single sample of blood was analysed for retinol, α-tocopherol, vitamin C, zinc, copper, total cholesterol and serum protein. Of the subjects, 11% had evidence of marginal vitamin A deficiency (retinol < 30 üg/dl), 2% of marginal vitamin E deficiency (α-tocopherol < 400 üg/dl) and 16% were vitamin C deficient (vitamin C < 0.29 mg/dl). About two-thirds of the participants had levels of serum zinc which were subnormal (< 70.0 üg/dl). The subjects were divided into three groups on the basis of the serum retinol concentration and the third with the lowest serum retinol had significantly lower serum protein, cholesterol, α-tocopherol and α-tocopherol: cholesterol ratio. A significant positive correlation was observed between serum retinol and serum α-tocopherol, serum cholesterol and serum zinc; while there was a negative correlation with serum copper. Serum retinol was entered as the dependent variable in a multiple regression analysis and the overall F-ratio (8.7) was highly significant (P = 0.0000), the adjusted ä-square was 0.152 (multiple R = 0.415). Family income, expenditure on food, fathers' education, serum α-tocopherol and serum copper were found to have a significant independent relationship with serum retinol.
    07/2009; 49(1):39-44.
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    ABSTRACT: Mechanisms underlying the lipodystrophy syndrome associated with antiretroviral therapy (ART) for HIV infection are not completely understood. We investigated the effect of ART on blood lipid concentrations in the fasting state and after consumption of a meal containing [1-13C]palmitic acid in HIV-positive men receiving nucleoside reverse transcriptase inhibitors (NRTI, n 7), NRTI combined with protease inhibitors (PI; NRTIPI, n 6), in HIV-positive but therapy-naïve men (noART, n 5) and in HIV-seronegative men (controls, n 6). HIV-positive subjects had higher fasting TAG concentrations and resting energy expenditure than controls. Subjects receiving NRTIPI therapy had higher fasting NEFA concentrations than the other groups. There were no significant differences in postprandial lipid metabolism between noART subjects and controls. NRTI therapy impaired hydrolysis of meal-derived TAG, most evidently when combined with PI (the NRTIPI group). Accumulation of 13C-label in the NEFA fraction was not different between groups. In the NRTIPI group, fasting and postprandial NEFA concentrations were significantly higher than other groups. Postprandial glucose and insulin responses in HIV-positive subjects did not differ from controls. These findings suggest that ART dyslipidaemia is associated with impaired postprandial TAG clearance, which is exacerbated by NRTIPI therapy. If dyslipidaemia is to be minimised in ART, the specific adverse effects of particular combinations during the fed state should be considered.
    The British journal of nutrition 07/2009; 102(7):1038-46. · 3.45 Impact Factor
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    ABSTRACT: Exclusive enteral nutrition is used as primary therapy in Crohn's disease. Nutrition support is frequently required in children with both Crohn's disease and Ulcerative Colitis when acutely unwell and during periods of recovery. There is considerable controversy about nutritional needs during phases of active and inactive disease. It is, for example, often assumed that in acute illness a child requires increased nutritional support however the precise relationship between illness severity and energy expenditure is uncertain. This study explores the relationship between disease activity and resting energy expenditure (REE) in children with inflammatory bowel disease. Patients were recruited from the regional paediatric gastroenterology unit at Southampton University Hospitals NHS Trust. Disease activity was assessed using standard scoring systems (Paediatric Crohn's Disease Activity Index; Simple Colitis Activity Index) and biochemical markers of inflammation (C-Reactive Protein, CRP). Fat free mass was estimated from skinfold thickness and Bioelectrical Impedance Analysis. Resting energy expenditure was measured by indirect calorimetry. A logarithmic correction and a linear regression model were used for analysis of REE corrected for body size. 55 children were studied; 37 (67%) with Crohn's disease and 18 (33%) with Ulcerative Colitis. Median PCDAI was 10 (range 0-60), 22 (59%) had PCDAI > or =10 (active disease). Median SCAI was 1.5 (range 0-12). Within disease groups there were strong correlations between REE/KgFFM(0.52) and disease activity; PCDAI (r -0.386, p 0.018) in Crohn's disease and SCAI (r -0.456, p 0.057) in Ulcerative Colitis. In the cohort as a whole there was no increase in REE/KgFFM(0.52) with increasing CRP (r 0.129, p 0.361). Using the regression model each mg/l increase in CRP was associated with a reduction in REE of nearly 1.5 kCal/day. We were unable to demonstrate a significant relationship between REE and disease activity in children with inflammatory bowel disease.
    Clinical nutrition (Edinburgh, Scotland) 06/2009; 28(6):652-6. · 3.27 Impact Factor
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    ABSTRACT: Prenatal nutritional constraint is associated with increased risk of metabolic dysregulation in adulthood contingent on adult diet. In rats, folic acid supplementation of a protein-restricted (PR) diet during pregnancy prevents altered phenotype and epigenotype in the offspring induced by the PR diet. We hypothesized that increasing folic acid intake during the juvenile-pubertal (JP) period would reverse the effects of a maternal PR diet on the offspring. Rats were fed a control (C) or PR diet during pregnancy and AIN93G during lactation. Offspring were weaned on d 28 onto diets containing 1 mg [adequate folate (AF)] or 5 mg [folic acid-supplemented (FS)] folic acid/kg feed. After 28 d, all offspring were fed a high-fat (18% wt:wt) diet and killed on d 84. As expected, offspring of PR dams fed the AF diet had increased fasting plasma triglyceride (TAG) and beta-hydroxybutyrate (betaHB) concentrations. The FS diet induced increased weight gain, a lower plasma betaHB concentration, and increased hepatic and plasma TAG concentration compared with AF offspring irrespective of maternal diet. PPARalpha and glucocorticoid receptor promoter methylation increased in liver and insulin receptor promoter methylation decreased in liver and adipose tissue in FS compared with AF offspring, with reciprocal changes in mRNA expression irrespective of maternal diet. These findings show that increased folic acid intake during the JP period did not simply reverse the phenotype induced by the maternal diet. This may represent a period of plasticity when specific nutrient intakes may alter the phenotype of the offspring through epigenetic changes in specific genes.
    Journal of Nutrition 05/2009; 139(6):1054-60. · 4.20 Impact Factor
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    ABSTRACT: Anthropometric indices of adiposity include BMI, waist circumference and waist:height ratio. In the recruitment phase of a prospective cohort study carried out between 1998 and 2002 we studied a population sample of 11 786 white Caucasian non-pregnant women in Southampton, UK aged 20-34 years, and explored the extent to which proposed cut-off points for the three indices identified the same or different women and how these indices related to adiposity. Height, weight and waist circumference were measured and fat mass was estimated from skinfold thicknesses; fat mass index was calculated as fat mass/height1.65. Of the subjects, 4869 (42 %) women were overweight (BMI > or = 25 kg/m2) and 1849 (16 %) were obese (BMI > or = 30 kg/m2). A total of 890 (8 %) subjects were not overweight but had a waist circumference > or = 80 cm and 748 (6 %) subjects were overweight but had a waist circumference < 80 cm (6 %). Of the women, 50 % had a BMI > or = 25 kg/m2 or a waist circumference > or = 80 cm or a waist:height ratio > or = 0.5. Of the variation in fat mass index, 85 % was explained by BMI, 76 % by waist circumference and 75 % by waist:height ratio. Our findings demonstrate that many women are differentially classified depending on which index of adiposity is used. As each index captures different aspects of size in terms of adiposity, there is the need to determine how the three indices relate to function and how they can be of use in defining risk of ill health in women.
    The British journal of nutrition 02/2009; 101(3):424-30. · 3.45 Impact Factor

Publication Stats

2k Citations
175.24 Total Impact Points

Institutions

  • 2011–2014
    • NIHR Oxford Biomedical Research
      Oxford, England, United Kingdom
  • 2012–2013
    • University Hospital Southampton NHS Foundation Trust
      Southampton, England, United Kingdom
  • 2004–2012
    • University of Surrey
      Guilford, England, United Kingdom
  • 1997–2010
    • University of Southampton
      • • Institute of Human Nutrition
      • • Developmental Origins of Health and Disease
      • • MRC Lifecourse Epidemiology Unit
      Southampton, ENG, United Kingdom