Physical activity is prospectively associated with adolescent nonalcoholic fatty liver disease

Objectives: The aim of the present study was to assess whether objectively measured physical activity at mean ages 12 and 14 years are prospectively associated with ultrasound scan liver fat and stiffness (alanine aminotransferase, aspartate aminotransferase [AST], and [gamma]-glutamyl transferase [GGT]) assessed at mean age 17.8 years. Methods: Participants were from the Avon Longitudinal Study of Parents and Children. Total physical activity (counts per minute) and minutes of moderate to vigorous physical activity (MVPA) were measured using ActiGraph accelerometers at mean ages 12 and 14 years. Results: Greater total physical activity and MVPA at ages 12 and 14 years were associated with lower odds of liver fat and lower GGT levels at mean age 17.8 years, such as per 15-minute increase in daily MVPA at age 12 years, the confounder adjusted odds ratio of liver fat was 0.47 (95% confidence interval [CI] 0.27–0.84). Associations attenuated after additional adjustment for fat mass as a potential confounder (eg, per 15-minute increase in daily MVPA at age 12 years, the odds ratio of liver fat attenuated to 0.65 [95% CI 0.35–1.21]) or a potential mediator (eg, per 15-minute increase in daily MVPA at age 12 years the odds ratio of liver fat attenuated to 0.59 [95% CI 0.32–1.09]). Results did not further attenuate after additional adjustment for insulin resistance. There was some evidence that greater total physical activity and MVPA at age 12 years were associated with the higher AST levels. Conclusions: Adolescents who were more active in childhood have lower odds of fatty liver and lower GGT levels. These findings are likely to be, at least in part, explained by adiposity

Weight trajectories through infancy and childhood and risk of non-alcoholic fatty liver disease in adolescence: the ALSPAC study

Background and Aims: Adiposity is a key risk factor for NAFLD. Few studies have examined prospective associations of infant and childhood adiposity with subsequent NAFLD risk. We examined associations of weight-for-height trajectories from birth to age 10 with liver outcomes in adolescence, and assessed the extent to which associations are mediated through fat mass at the time of outcome assessment.<p></p> Methods: Individual trajectories of weight and height were estimated for participants in the Avon Longitudinal Study of Parents and Children using random-effects linear-spline models. Associations of birthweight (adjusted for birth length) and weight change (adjusted for length/height change) from 0–3 months, 3 months–1 y, 1–3 y, 3–7 y, and 7–10 y with ultrasound scan (USS) determined liver fat and stiffness, and serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyl transferase (GGT) at mean age 17.8 y were assessed with linear and logistic regressions. Mediation by concurrent fat mass was assessed with adjustment for fat mass at mean age 17.8 y.<p></p> Results: Birth weight was positively associated with liver stiffness and negatively with ALT and AST. Weight change from birth to 1 y was not associated with outcomes. Weight change from 1–3 y, 3–7 y, and 7–10 y was consistently positively associated with USS and blood-based liver outcomes. Adjusting for fat mass at mean age 17.8 y attenuated associations toward the null, suggesting associations are largely mediated by concurrent body fatness.<p></p> Conclusions: Greater rates of weight-for-height change between 1 y and 10 y are consistently associated with adverse liver outcomes in adolescence. These associations are largely mediated through concurrent fatness

Use of soil moisture information in yield models

There are no author-identified significant results in this report

Studies on Pre-slaughter Handling of Pigs and its Relationship to Meat Quality

End of Project ReportsTwo quality defects of pork which are affected by preslaughter handling are PSE (Pale Soft Exudative) and DFD (Dark Firm Dry) meat. The incidence of PSE pork is mainly a function of the breed of pig but short-term stressful handling before slaughter and feeding too close to slaughter are also involved. DFD meat is a result of prolonged stressful handling. PSE meat is pale and uneven in colour and exudes fluid making it unattractive in the retail display while dark meat appears stale and is prone to bacterial spoilage. After slaughter muscle metabolism continues and muscle glycogen is converted to lactic acid reducing meat pH. Prolonged stress results in glycogen depletion, pre-slaughter feeding results in elevated levels. Colour may be assessed subjectively by eye or objectively by a meter colour but pH of the meat is closely related to colour and measurement of pH at 45 minutes post-slaughter is frequently used to predict ultimate colour and pH. The objective of this study was to examine pre-slaughter handling practices and their relationship with meat quality (pH, colour). In the first trial, a survey of the amounts of stomach contents in pigs at slaughter in two factories found similar amounts to comparable surveys in France and the UK. It was concluded that most pigs had been fasted for an adequate time before delivery. The relationship between the amount of stomach contents and meat quality in this survey was poor. In the second trial, pigs from the Moorepark herd fed by either a computerised wet feeding system or an ad libitum dry feed system were slaughtered after overnight fasting or with feed available up to loading for transport to the factory, two to three hours before slaughter. There was no difference between feeding systems in meat colour or pH but fasted pigs, on both feeding systems, had darker meat and meat of a higher pH. In the third and fourth trials a survey of transport vehicles was carried out and meat quality of pigs delivered in modern and old-type vehicles was compared. Most trucks examined (78%) were four years old or more. Few had modern hydraulic lifting gear for the top decks. Space allowances during transportation were generally adequate but delays in unloading could, in warm weather, cause stress on pigs. There was little evidence for an effect of vehicle on meat quality parameters but day to day variation in carcass temperature and pH suggested a need for further research on factory influences on meat quality. Feeding of Magneium Aspartate to pigs for the last 5 days prior to slaughter has been shown, in Australia, to have a beneficial effect on meat colour and drip loss. In the final trial in this study Mg Asp had no effect on meat quality parameters.European Union Structural Funds (EAGGF

Complexity of a complex trait locus: HP, HPR, haemoglobin and cholesterol

HP and HPR are related and contiguous genes in strong linkage disequilibrium (LD), encoding haptoglobin and haptoglobin-related protein. These bind and chaperone free Hb for recycling, protecting against oxidation. A copy number variation (CNV) within HP (Hp1/Hp2) results in different possible haptoglobin complexes which have differing properties. HPR rs2000999 (G/A), identified in meta-GWAS, influences total cholesterol (TC) and LDL-cholesterol (LDL-C). We examined the relationship between HP CNV, HPR rs2000999, Hb, red cell count (RCC), LDL-C and TC in the British Women's Heart and Health Study (n=2779 for samples having CNV, rs2000999, and phenotypes). Analysing single markers by linear regression, rs2000999 was associated with LDL-C (β=0.040 mmol/L, p=0.023), TC (β=-0.040 mmol/L, p=0.019), Hb (β=-0.044 g/dL, p=0.028) and borderline with RCC (β=-0.032 × 10(12)/L, p=0.066). Analysis of CNV by linear regression revealed an association with Hb (Hp1 vs Hp2, β=0.057 g/dL, p=0.004), RCC (β=0.045 × 10(12)/L, p=0.014), and showed a trend with LDL-C and TC. There were 3 principal haplotypes (Hp1-G 36%; Hp2-G 45%; Hp2-A 18%). Haplotype comparisons showed that LDL-C and TC associations were from rs2000999; Hb and RCC associations derived largely from the CNV. Distinct genotype-phenotype effects are evident at the genetic epidemiological level once LD has been analysed, perhaps reflecting HP-HPR functional biology and evolutionary history. The derived Hp2 allele of the HP gene has apparently been subject to malaria-driven positive selection. Haptoglobin-related protein binds Hb and apolipoprotein-L, i.e. linking HPR to the cholesterol system; and the HPR/apo-L complex is specifically trypanolytic. Our analysis illustrates the complex interplay between functions and haplotypes of adjacent genes, environmental context and natural selection, and offers insights into potential use of haptoglobin or haptoglobin-related protein as therapeutic agents.Philip A.I. Guthrie, Santiago Rodriguez, Tom R. Gaunt, Debbie A. Lawlor George Davey Smith, Ian N.M. Da

Nonstomatal limitations are responsible for drought-induced photosynthetic inhibition in four C4 grasses

Here, the contribution of stomatal and nonstomatal factors to photosynthetic inhibition under water stress in four tropical C(4) grasses was investigated (Panicum coloratum, Bothriochloa bladhii, Cenchrus ciliaris and Astrebla lappacea ). Plants were grown in well watered soil, and then the effects of soil drying were measured on leaf gas exchange, chlorophyll a fluorescence and water relations. During the drying cycle, leaf water potential (Psi(leaf)) and relative water content (RWC) decreased from c. -0.4 to -2.8 MPa and 100-40%, respectively. The CO(2) assimilation rates (A) and quantum yield of PSII (Phi(PSII)) of all four grasses decreased rapidly with declining RWC. High CO(2) concentration (2500 mul l(-1)) had no effect on A or Phi(PSII) at any stage of the drying cycle. Electron transport capacity and dark respiration rates were unaltered by drought. The CO(2) compensation concentrations of P. coloratum and C. ciliaris rose sharply when leaf RWC fell below 70%. In P. coloratum, 5% CO(2) did not prevent the decline of O(2) evolution rates under water stress. We conclude that inhibition of photosynthesis in the four C(4) grasses under water stress is dependent mainly on biochemical limitations

Associations of cord leptin and cord insulin with adiposity and blood pressure in White British and Pakistani children aged 4/5 years.

Background: Cord leptin and cord insulin concentrations may be important biomarkers of child adiposity and cardiovascular health, especially in populations with an increased long-term risk of type 2 diabetes and cardiovascular diseases. We aimed to determine whether cord leptin and insulin are associated with adiposity and early cardiovascular health at age 4/5, and whether any associations differ between White British and Pakistani children. Methods: Using bi-ethnic cohort data from 6060 mother-offspring pairs (2717 (44.8%) White British, 3343 (55.2%) Pakistani), we examined associations of cord leptin and insulin with adiposity (BMI, skinfold thickness) and systolic and diastolic blood pressure at age 4/5. Results: Cord leptin and insulin were higher in Pakistani compared to White British children (7.4 ng/ml versus 6.7 ng/ml and 4.1 mU/L versus 3.63 mU/L , respectively). Associations with adiposity measurements were similar in both groups and close to the null value. For example, each 10 ng/ml higher cord leptin was associated with a difference in mean childhood BMI of 0.10 kg/m 2 (95% CI 0.01, 0.19) in White British, 0.01 kg/m 2 (95% CI -0.08, 0.10) in Pakistani and 0.04 kg/m 2 (95% CI -0.02, 0.11) in both groups combined.  Associations with systolic and diastolic blood pressure were also close to the null and consistent in both groups. Conclusions: We found no evidence that cord leptin or insulin were likely to be valuable biomarkers for predicting later adiposity and blood pressure in White British or Pakistani children. For now, other factors such as family history and social-economic status may be more useful markers of risk

Associations of social and economic and pregnancy exposures with blood pressure in UK White British and Pakistani children age 4/5.

South Asians have higher rates of coronary heart disease (CHD) than White European individuals. Blood pressure (BP) is one of the most important risk factors for CHD and ethnic differences in BP have been identified in childhood. Early life exposures could explain some of these differences. We examined associations of family social and economic and maternal pregnancy exposures and BP at age 4/5 in 1644 White British and 1824 Pakistani mother-offspring pairs from the Born in Bradford study. We found that systolic BP was similar but diastolic BP was higher, in Pakistani compared to White British children (adjusted mean differences were -0.170 mmHg 95% CI -0.884, 0.543 for systolic BP; 1.328 mmHg 95% CI 0.592, 2.064 for diastolic BP). Social and economic exposures were not associated with BP in either ethnic group. Maternal BMI was positively associated with BP in both groups but this association was mediated by child BMI. Only gestational hypertension was associated with child systolic and diastolic BP and this was only identified in Pakistani mother-offspring pairs. These findings suggest that Pakistani populations may have a different BP trajectory compared to White British groups and that this is already evident at age 4/5 years