Differential DNA methylation of steatosis and non-alcoholic fatty liver disease in adolescence.

BACKGROUND AND AIMS: Epigenetic modifications are associated with hepatic fat accumulation and non-alcoholic fatty liver disease (NAFLD). However, few epigenetic modifications directly implicated in such processes have been identified during adolescence, a critical developmental window where physiological changes could influence future disease trajectory. To investigate the association between DNA methylation and NAFLD in adolescence, we undertook discovery and validation of novel methylation marks, alongside replication of previously reported marks. APPROACH AND RESULTS: We performed a DNA methylation epigenome-wide association study (EWAS) on DNA from whole blood from 707 Raine Study adolescents phenotyped for steatosis score and NAFLD by ultrasound at age 17. Next, we performed pyrosequencing validation of loci within the most 100 strongly associated differentially methylated CpG sites (dmCpGs) for which ≥ 2 probes per gene remained significant across four statistical models with a nominal p value < 0.007. EWAS identified dmCpGs related to three genes (ANK1, MIR10a, PTPRN2) that met our criteria for pyrosequencing. Of the dmCpGs and surrounding loci that were pyrosequenced (ANK1 n = 6, MIR10a n = 7, PTPRN2 n = 3), three dmCpGs in ANK1 and two in MIR10a were significantly associated with NAFLD in adolescence. After adjustment for waist circumference only dmCpGs in ANK1 remained significant. These ANK1 CpGs were also associated with γ-glutamyl transferase and alanine aminotransferase concentrations. Three of twenty-two differentially methylated dmCpGs previously associated with adult NAFLD were associated with NAFLD in adolescence (all adjusted p < 2.3 × 10-3). CONCLUSIONS: We identified novel DNA methylation loci associated with NAFLD and serum liver biochemistry markers during adolescence, implicating putative dmCpG/gene regulatory pathways and providing insights for future mechanistic studies.

Comparison of the cardiometabolic profiles of adolescents conceived through ART with those of a non-ART cohort.

STUDY QUESTION: Is the cardiometabolic health of adolescents conceived through ART worse than that of their counterparts conceived without ART? SUMMARY ANSWER: The majority of cardiometabolic and vascular health parameters of adolescents conceived through ART are similar or more favourable, than those of their counterparts of similar age and conceived without ART. WHAT IS KNOWN ALREADY: It has been proposed that the cardiometabolic health of offspring conceived with ART may be unfavourable compared to that of their counterparts conceived without ART. The literature pertaining to cardiometabolic health of offspring conceived after ART is contradictory, but generally suggests unfavourable cardiometabolic health parameters, such as an increase in blood pressure (BP), vascular dysfunction and adiposity, as well as unfavourable glucose and lipid profiles. With over 8 million children and adults born through ART worldwide, it is important to investigate whether these early signs of adverse cardiometabolic differences persist into adolescence and beyond. STUDY DESIGN, SIZE, DURATION: The Growing Up Healthy Study (GUHS) is a prospective cohort study that recruited 303 adolescents and young adults conceived after ART (aged 13-21 years) and born between 1991 and 2001 in Western Australia. Their health parameters, including cardiometabolic factors, were assessed and compared with counterparts from the Raine Study Generation 2 (Gen2). The 2868 Gen2 participants were born 1989-1992 and are representative of the Western Australian adolescent population. At ∼17 years of age (2013-2017), 163 GUHS participants replicated assessments previously completed by Gen2 at a similar age. PARTICIPANTS/MATERIALS, SETTING, METHODS: Cardiometabolic parameters were compared between a total of 163 GUHS and 1457 Gen2 adolescents. Separate male (GUHS n = 81, Gen2 n = 735) and female (GUHS n = 82, Gen2 n = 722) analyses were conducted. Assessments consisted of a detailed questionnaire including health, lifestyle and demographic parameters, anthropometric assessments (height, weight, BMI, waist circumference and skinfold thickness), fasting serum biochemistry, arterial stiffness and BP (assessed using applanation tonometry). Abdominal ultrasonography was used to assess the presence and severity of hepatic steatosis, and thickness of abdominal fat compartments. Non-alcoholic fatty liver disease (NAFLD) was diagnosed if there was sonographic fatty liver in the absence of significant alcohol consumption. Chi2, Fisher's exact and Mann-Whitney U tests, performed in SPSS V25, examined cohort differences and generalized estimating equations adjusted for the following covariates: singleton vs non-singleton pregnancy, birthweight (z-score), gestational age, BMI, smoking, alcohol consumption in the past 6 months and parent cardiovascular status. Arterial stiffness measures and waist circumference were additionally adjusted for height, and female analyses were additionally adjusted for use of oral contraceptives in the preceding 6 months. MAIN RESULTS AND THE ROLE OF CHANCE: In adjusted analyses, GUHS females had a lower BMI (22.1 vs 23.3 kg/m2, P = 0.014), and thinner skinfolds (triceps, subscapular, mid-abdominal; 16.9 vs 18.7 mm, P = 0.021, 13.4 vs 15.0 mm, P = 0.027, 19.7 vs 23.2 mm, P < 0.001, respectively), whereas males were not significantly different. Waist circumference was lower in GUHS adolescents (males: 78.1 vs 81.3 cm, P = 0.008, females: 76.7 vs 83.3 cm, P = 0.007). There were no significant differences between the two groups in glucose, insulin, homeostatic model assessment for insulin resistance, low-density lipoprotein cholesterol, non-high-density lipoprotein cholesterol (non-HDL-C), total cholesterol (TC), alanine aminotransferase and high-sensitivity C-reactive protein in both sexes. In females, serum triglycerides were lower in GUHS adolescents (1.0 vs 1.2 mmol/l, P = 0.029). GUHS males had higher serum HDL-C (1.1 vs 1.0 mmol/l, P = 0.004) and a lower TC/HDL-C ratio (3.2 vs 3.6, P = 0.036). There were no significant differences in the prevalence of NAFLD or steatosis severity scores between the cohorts in males and females. GUHS females had less subcutaneous adipose tissue (9.4 vs 17.9 mm, P < 0.001), whereas GUHS males had greater visceral adipose thickness (44.7 vs 36.3 mm, P < 0.001). There was no significant difference in pre-peritoneal adipose thickness. Pulse wave velocity was lower in GUHS males (5.8 vs 6.3 m/s, P < 0.001) and heart rate corrected augmentation index was lower in GUHS females (-8.4 vs -2.7%, P = 0.048). There were no significant differences in BP or heart rate in males or females between the two groups. LIMITATIONS, REASONS FOR CAUTION: Despite the substantial study size and the unique study design of the ART cohort, we were unable to differentiate between different types of ART, due to the low number of ICSI cycles (e.g. IVF vs ICSI), draw definite conclusions, or relate the outcomes to the cause of infertility. Considering the differences in time points when both cohorts were studied, external factors could have changed, which could not be accounted for. Given the observational nature of this study, causation cannot be proven. WIDER IMPLICATIONS OF THE FINDINGS: Contrary to our hypothesis and previous findings focussing mainly on childhood, this study reports mostly similar or favourable cardiometabolic markers in adolescents conceived with ART compared to those conceived without ART. The greater visceral adipose thickness, particularly present in males, requires further investigation. While these findings are generally reassuring, future well-designed and appropriately powered studies are required to definitively address the issue of cardiometabolic health in ART adults. STUDY FUNDING/COMPETING INTEREST(S): This project was supported by NHMRC project grant number 1042269 and R.J.H. received education grant funding support from Ferring Pharmaceuticals. R.J.H. is the Medical Director of Fertility Specialists of Western Australia and a shareholder in Western IVF. He has received educational sponsorship from MSD, Merck-Serono and Ferring Pharmaceuticals. P.B. is the Scientific Director of Concept Fertility Centre, Subiaco, Western Australia. J.L.Y. is the Medical Director of PIVET Medical Centre, Perth, Western Australia. TRIAL REGISTRATION NUMBER: N/A.

Arthropathy in hereditary haemochromatosis segregates with elevated erythrocyte mean corpuscular volume.

Objective: To evaluate the relationship between erythrocyte parameters and the presence or absence of arthritis in HFE C282Y homozygous hereditary haemochromatosis (HH) subjects compared to control groups of non-HH subjects with arthritis.Method: Erythrocyte and arthritis parameters [mean corpuscular volume (MCV) and mean cell haemoglobin (MCH)] were obtained from consecutive HH subjects (n = 119) who were referred for initial evaluation and management. For comparison, MCV and MCH values were collected from randomly selected non-HH subjects with rheumatoid arthritis (n = 100) and osteoarthritis (n = 100), consisting of equal numbers of men and women. Two other comparison groups comprised 16 men and women who were heterozygous for C282Y with arthritis, and 38 non-HH subjects with type 2 polyarticular osteoarthritis (T2POA).Results: MCV values were significantly higher in HH subjects with arthritis (95 ± 0.56 fL) than in HH subjects without arthritis (92.75 ± 0.50 fL, p = 0.037). HH subjects with or without arthritis demonstrated a higher mean MCV than the control groups of non-HH osteoarthritis (90.12 ± 0.46 fL, p < 0.001) and non-HH rheumatoid arthritis (90.94 ± 0.57 fL, p < 0.001). HH subjects with arthritis also demonstrated a higher MCV than heterozygous C282Y subjects with arthritis (93.18 ± 1.55 fL, p = 0.025) and non-HH subjects with a similar pattern of arthritis, notably T2POA (91.13 ± 0.50 fL, p < 0.01). An MCV of ≥ 97.85 fL provided a likelihood ratio of 2.2 for development of arthritis in HH subjects.Conclusion: This study demonstrated a relationship between elevated MCV and arthritis in incident cases of HH.

Features of the metabolic syndrome in late adolescence are associated with impaired testicular function at 20 years of age.

STUDY QUESTION: Are early signs of metabolic disorder in late adolescence associated with features of impaired testicular function many years before the majority seek parenthood? SUMMARY ANSWER: Adolescents with features of metabolic disorder at 17 years, or insulin resistance (IR) at 20 years of age, show impaired testicular function and altered hormone levels compared to those without metabolic disorder. WHAT IS KNOWN ALREADY: Controversial evidence suggests a recent decline in sperm production potentially linked to environmental influences, but its cause remains unclear. Concomitant increases in obesity and diabetes suggest that lifestyle factors may contribute to this decline in testicular function. Although obesity has been associated with adverse testicular function in some studies, it remains unclear whether poor testicular function merely reflects, or causes, poor metabolic health. If metabolic disorder were present in adolescence, prior to the onset of obesity, this may suggest that metabolic disorder maybe a precursor of impaired testicular function. STUDY DESIGN, SIZE, DURATION: The Western Australian Pregnancy Cohort (Raine) Study is a longitudinal study of children born in 1989-1991 who have undergone detailed physical assessments since birth (1454 male infants born). At 17 years of age, 490 boys underwent a hepatic ultrasound examination, serum cytokine assessment (n = 520) and a metabolic assessment (n = 544). A further metabolic assessment was performed at 20 years (n = 608). Testicular assessment was performed at 20 years; 609 had reproductive hormones measured, 404 underwent a testicular ultrasound and 365 produced a semen sample. PARTICIPANTS/MATERIALS, SETTING, METHODS: Testicular volume was estimated by ultrasonography, and semen analysis was performed according to World Health Organization guidelines. Concentrations of LH, FSH and inhibin B (inhB) in serum were measured by immunoassay and total testosterone by liquid chromatography-mass spectrometry.At 17 years of age, a liver ultrasound examination was performed to determine the presence of non-alcoholic fatty liver disease (NAFLD), and serum analysed for the cytokines interleukin-18 and soluble tumour necrosis factor receptor 1 and 2 (sTNFR1, sTNFR2).At 17 and 20 years of age, fasting blood samples were analysed for serum liver enzymes, insulin, glucose, triglycerides (TG), total cholesterol, high density lipoprotein and low density lipoprotein cholesterol, high sensitivity C-reactive protein and uric acid. The homoeostatic model assessment (HOMA) was calculated and approximated IR was defined by a HOMA >4. Anthropometric data was collected and dual energy X-ray absorptiometry measurement performed for lean and total fat mass. As at this young age the prevalence of metabolic syndrome was expected to be low, a two-step cluster analysis was used using waist circumference, TGs, insulin, and systolic blood pressure to derive a distinct high-risk group with features consistent with the metabolic syndrome and increased cardiometabolic risk. MAIN RESULTS AND THE ROLE OF CHANCE: Men at age 17 years with increased cardiometabolic risk had lower concentrations of serum testosterone (medians: 4.0 versus 4.9 ng/mL) and inhB (193.2 versus 221.9 pg/mL) (P < 0.001 for both) compared to those within the low risk metabolic cluster. Men with ultrasound evidence of NAFLD (n = 45, 9.8%) had reduced total sperm output (medians: 68.0 versus 126.00 million, P = 0.044), testosterone (4.0 versus 4.7 ng/mL, P = 0.005) and inhB (209.1 versus 218.4 pg/mL, P = 0.032) compared to men without NAFLD.Men with higher concentrations of sTNFR1 at 17 years of age had a lower sperm output and serum concentration of inhB, with an increase in LH and FSH (all P < 0.05 after adjustment for age, BMI, abstinence and a history of cryptorchidism, varicocele, cigarette smoking, alcohol and drug use), compared to those without an elevated sTNFR1. Multivariable regression analysis, adjusting for confounders, demonstrated that men in the high-risk metabolic cluster at 20 years had a lower serum testosterone and inhB (P = 0.003 and P = 0.001, respectively). A HOMA-IR > 4 was associated with a lower serum testosterone (P = <0.001) and inhB (P = 0.010) and an increase in serum FSH (P = 0.015). LIMITATIONS, REASONS FOR CAUTION: This study is limited by the sample size and multiple comparisons, and causality cannot be proven from an observational study. Due to a 3-year interval between some metabolic assessments and assessment of testicular function, we cannot exclude the introduction of a bias into the study, as some of the participants and their testicular function will not have been fully mature at the 17-year assessment. WIDER IMPLICATIONS OF THE FINDINGS: Irrespective of a proven causation, our study findings are important in that a significant minority of the men, prior to seeking parenthood, presented co-existent features of metabolic disorder and signs of testicular impairment. Of particular note is that the presence of NAFLD at 17 years of age, although only present in a minority of men, was associated with an almost 50% reduction in sperm output at 20 years of age, and that the presence of IR at 20 years was associated with a 20% reduction in testicular volume. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by Australian NHMRC (Grant Numbers 634457, 35351417 and 403981) and received support from the Raine Medical Research Foundation, The Telethon Kids Institute, University of Western Australia, Women and Infants Research Foundation, Curtin University and Edith Cowan University. D.A.D., J.E.D., N.M., L.A.A., R.-C.H., T.A.M., J.K.O., L.J.B. have nothing to declare. R.J.H. is Medical Director of Fertility Specialists of Western Australia, has equity interests in Western IVF, and has received grant support from MSD, Merck-Serono and Ferring Pharmaceuticals. RMcL has equity interests in the Monash IVF Group. R.J.N. has equity interests in FertilitySA, and has received grant support from Merck Serono and Ferring Pharmaceuticals. D.J.H. has received institutional grant funding (but no personal income) for investigator-initiated testosterone pharmacology studies from Lawley and Besins Healthcare and has provided expert testimony to anti-doping tribunals and for testosterone litigation.This abstract was awarded the Fertility Society of Australia clinical exchange award for the oral presentation at ESHRE, Barcelona, in 2018.

Brain iron accumulation affects myelin-related molecular systems implicated in a rare neurogenetic disease family with neuropsychiatric features.

The 'neurodegeneration with brain iron accumulation' (NBIA) disease family entails movement or cognitive impairment, often with psychiatric features. To understand how iron loading affects the brain, we studied mice with disruption of two iron regulatory genes, hemochromatosis (Hfe) and transferrin receptor 2 (Tfr2). Inductively coupled plasma atomic emission spectroscopy demonstrated increased iron in the Hfe-/- × Tfr2mut brain (P=0.002, n ≥5/group), primarily localized by Perls' staining to myelinated structures. Western immunoblotting showed increases of the iron storage protein ferritin light polypeptide and microarray and real-time reverse transcription-PCR revealed decreased transcript levels (P<0.04, n ≥5/group) for five other NBIA genes, phospholipase A2 group VI, fatty acid 2-hydroxylase, ceruloplasmin, chromosome 19 open reading frame 12 and ATPase type 13A2. Apart from the ferroxidase ceruloplasmin, all are involved in myelin homeostasis; 16 other myelin-related genes also showed reduced expression (P<0.05), although gross myelin structure and integrity appear unaffected (P>0.05). Overlap (P<0.0001) of differentially expressed genes in Hfe-/- × Tfr2mut brain with human gene co-expression networks suggests iron loading influences expression of NBIA-related and myelin-related genes co-expressed in normal human basal ganglia. There was overlap (P<0.0001) of genes differentially expressed in Hfe-/- × Tfr2mut brain and post-mortem NBIA basal ganglia. Hfe-/- × Tfr2mut mice were hyperactive (P<0.0112) without apparent cognitive impairment by IntelliCage testing (P>0.05). These results implicate myelin-related systems involved in NBIA neuropathogenesis in early responses to iron loading. This may contribute to behavioral symptoms in NBIA and hemochromatosis and is relevant to patients with abnormal iron status and psychiatric disorders involving myelin abnormalities or resistant to conventional treatments.

Detection of liver injury in IBD using transient elastography.

BACKGROUND: Up to 5% of inflammatory bowel disease (IBD) patients are thought to have clinically significant liver disease due to multifactorial causes, however, this figure may be an underestimate due to reliance on abnormal liver tests (LTs) and/or liver biopsies. AIMS: Our aim was to evaluate the prevalence of clinically significant liver disease in IBD patients as defined by an increased liver stiffness measurement (LS) ≥8kPa using transient elastography (TE). METHODS: 110 IBD patients, and 55 non-IBD control subjects, had their LS recorded using FibroScan® (EchoSense, Paris, France) by a single blinded operator trained in TE. RESULTS: 71 Crohn's disease and 39 ulcerative colitis subjects were included. All demographic variables were similar between the IBD and control groups apart from a significantly higher proportion of IBD patients who smoked (17.3% vs 3.6%, P=0.013). Seven IBD patients (6.4%) had an LS over 8 kPa and 3 had persistently elevated LS 6 months later. One patient had compensated cirrhosis. No significant differences in overall LS were observed between the IBD and control groups. Increased BMI and age, however, were independently associated with a higher LS in the IBD but not in the control group (P<0.001 and 0.010 respectively). CONCLUSION: Using TE, the prevalence of clinically significant liver disease in IBD patients is low. The association of increased BMI and age with increased LS in IBD suggests fatty liver disease being the prevailing aetiology in these patients.

Brain transcriptome perturbations in the transferrin receptor 2 mutant mouse support the case for brain changes in iron loading disorders, including effects relating to long-term depression and long-term potentiation.

Iron abnormalities within the brain are associated with several rare but severe neurodegenerative conditions. There is growing evidence that more common systemic iron loading disorders such as hemochromatosis can also have important effects on the brain. To identify features that are common across different forms of hemochromatosis, we used microarray and real-time reverse transcription polymerase chain reaction (RT-PCR) to assess brain transcriptome profiles of transferrin receptor 2 mutant mice (Tfr2(mut)), a model of a rare type of hereditary hemochromatosis, relative to wildtype control mice. The results were compared with our previous findings in dietary iron-supplemented wildtype mice and Hfe(-/-) mice, a model of a common type of hereditary hemochromatosis. For transcripts showing significant changes relative to controls across all three models, there was perfect (100%) directional concordance (i.e. transcripts were increased in all models or decreased in all models). Comparison of the two models of hereditary hemochromatosis, which showed more pronounced changes than the dietary iron-supplemented mice, revealed numerous common molecular effects. Pathway analyses highlighted changes for genes relating to long-term depression (6.8-fold enrichment, p=5.4×10(-7)) and, to a lesser extent, long-term potentiation (3.7-fold enrichment, p=0.01), with generalized reductions in transcription of key genes from these pathways, which are involved in modulating synaptic strength and efficacy and are essential for memory and learning. The agreement across the models suggests the findings are robust and strengthens previous evidence that iron loading disorders affect the brain. Perturbations of brain phenomena such as long-term depression and long-term potentiation might partly explain neurologic symptoms reported for some hemochromatosis patients.

Hereditary hemochromatosis is characterized by a clinically definable arthropathy that correlates with iron load.

OBJECTIVE: To determine the frequency and character of arthropathy in hereditary hemochromatosis (HH) and to investigate the relationship between this arthropathy, nodal interphalangeal osteoarthritis, and iron load. METHODS: Participants were recruited from the community by newspaper advertisement and assigned to diagnostic confidence categories for HH (definite/probable or possible/unlikely). Arthropathy was determined by use of a predetermined clinical protocol, radiographs of the hands of all participants, and radiographs of other joints in which clinical criteria were met. RESULTS: An arthropathy considered typical for HH, involving metacarpophalangeal joints 2-5 and bilateral specified large joints, was observed in 10 of 41 patients with definite or probable HH (24%), all of whom were homozygous for the C282Y mutation in the HFE gene, while only 2 of 62 patients with possible/unlikely HH had such an arthropathy (P=0.0024). Arthropathy in definite/probable HH was more common with increasing age and was associated with ferritin concentrations>1,000 µg/liter at the time of diagnosis (odds ratio 14.0 [95% confidence interval 1.30-150.89], P=0.03). A trend toward more episodes requiring phlebotomy was also observed among those with arthropathy, but this was not statistically significant (odds ratio 1.03 [95% confidence interval 0.99-1.06], P=0.097). There was no significant association between arthropathy in definite/probable HH and a history of intensive physical labor (P=0.12). CONCLUSION: An arthropathy consistent with that commonly attributed to HH was found to occur in 24% of patients with definite/probable HH. The association observed between this arthropathy, homozygosity for C282Y, and serum ferritin concentrations at the time of diagnosis suggests that iron load is likely to be a major determinant of arthropathy in HH and to be more important than occupational factors.

The C282Y polymorphism of the hereditary hemochromatosis gene is associated with increased sex hormone-binding globulin and normal testosterone levels in men.

BACKGROUND: Hereditary hemochromatosis resulting either from homozygosity for the C282Y polymorphism of the HFE gene, or compound heterozygosity for C282Y and H63D, manifests with liver disease and hypogonadism. However, it is unclear whether men who are heterozygotes for C282Y or H63D exhibit subtle abnormalities of sex hormone status. AIMS: To evaluate whether heterozygosity for either of the HFE gene polymorphisms C282Y or H63D is associated with circulating testosterone and SHBG in men. SUBJECTS AND METHODS: We performed a cross-sectional analysis of 388 community-dwelling men. Men were genotyped for C282Y and H63D. Sera were analysed for testosterone and SHBG, and insulin resistance was estimated using a homeostatic model (HOMA2-IR). RESULTS: Mean age of men in the cohort was 56.9 yr. Men who were heterozygous for the C282Y polymorphism in the HFE gene had higher SHBG levels than men who did not carry this polymorphism (mean ± SE, 38.2 ± 1.64 vs 32.8 ± 0.71 nmol/l, p=0.006). Total and free testosterone levels did not differ in the two groups. In multivariate analysis adjusting for potential confounders including age, waist circumference, testosterone, and HOMA2-IR, C282Y heterozygosity remained associated with SHBG levels (p<0.001). CONCLUSION: The C282Y polymorphism is associated with SHBG levels in men who do not manifest iron overload. Further studies are needed to clarify potential mechanisms and determine the clinical relevance of this finding.

Serum testosterone levels correlate with haemoglobin in middle-aged and older men.

BACKGROUND: Lower testosterone levels are associated with anaemia in older men and women. The relation between testosterone and haemoglobin (Hb) in younger and middle-aged men is less well defined. The aim of the study was to examine the association between testosterone and Hb levels in men spanning middle to older ages. METHODS: A cross-sectional analysis of 492 men aged 30.7-94.5 years from the Busselton Health Survey, Western Australia, was carried out. Haemoglobin (Hb), early-morning serum total testosterone and sex hormone-binding globulin (SHBG) were measured. Free testosterone was calculated using mass action equations. RESULTS: Haemoglobin correlated to total and free testosterone concentrations (r= 0.13, P= 0.003 and r= 0.20, P < 0.001, respectively). Hb and SHBG were inversely correlated (r=-0.14, P= 0.001). Hb increased across lowest to highest quartiles of total testosterone (P= 0.02) and free testosterone (P < 0.001), but not SHBG. After adjusting for age, waist circumference, smoking status, alcohol consumption, renal function and ferritin, total testosterone was associated with Hb (beta= 0.037, P= 0.003) as was free testosterone (beta= 2.32, P < 0.001), whereas SHBG was not associated. CONCLUSION: Testosterone concentration modulates Hb levels in community-dwelling men across a wide age range. Further studies are needed to clarify implications of this association between testosterone and Hb in men.

Outcomes for women in a flexible sigmoidoscopy-based colorectal cancer screening programme.

BACKGROUND: There are concerns that technical and anatomical factors can reduce the potential benefit of flexible sigmoidoscopy (FS) as a colorectal cancer (CRC) screening tool in women compared with men. Our aim was to review the outcomes for female participants in a community-based CRC screening project using FS. METHODS: In 1995, a programme of unsedated FS-based screening of asymptomatic average-risk individuals aged 55-64 years was established at Fremantle Hospital, Western Australia. Insertion depths, pathological findings and site of adenomas and subject-rated pain scores have been prospectively recorded. Later diagnoses of malignancy were determined by linkage of the cohort with the West Australian Cancer Registry. RESULTS: Between 1995 and 2005, 3402 primary screening FS examinations had been carried out (women 41%). Mean age of participants was 59.6 years. Women were more likely to undergo a FS with insertion depth less than 40 cm (17 vs 6%, P < 0.0001). Mean pain score was 2.9 for men and 4.0 for women (P < 0.0001). Women were less likely to have any neoplasia detected, independent of pain score or insertion depth (odds ratio 0.5, 95% confidence interval 0.4-0.6). Increasing insertion depth from 50 to 60 cm in a woman would only have a 0.4% chance of detecting any additional neoplasia. An insignificant trend to higher incidence of later interval CRC was observed in women with normal sigmoidoscopy. CONCLUSION: Women probably undergo FS with more discomfort and lesser insertion depth than men. It is unlikely that moderate increases in insertion depth would have a substantial benefit.

Iron absorption and hepatic iron uptake are increased in a transferrin receptor 2 (Y245X) mutant mouse model of hemochromatosis type 3.

Hereditary hemochromatosis type 3 is an iron (Fe)-overload disorder caused by mutations in transferrin receptor 2 (TfR2). TfR2 is expressed highly in the liver and regulates Fe metabolism. The aim of this study was to investigate duodenal Fe absorption and hepatic Fe uptake in a TfR2 (Y245X) mutant mouse model of hereditary hemochromatosis type 3. Duodenal Fe absorption and hepatic Fe uptake were measured in vivo by 59Fe-labeled ascorbate in TfR2 mutant mice, wild-type mice, and Fe-loaded wild-type mice (2% dietary carbonyl Fe). Gene expression was measured by real-time RT-PCR. Liver nonheme Fe concentration increased progressively with age in TfR2 mutant mice compared with wild-type mice. Fe absorption (both duodenal Fe uptake and transfer) was increased in TfR2 mutant mice compared with wild-type mice. Likewise, expression of genes participating in duodenal Fe uptake (Dcytb, DMT1) and transfer (ferroportin) were increased in TfR2 mutant mice. Nearly all of the absorbed Fe was taken up rapidly by the liver. Despite hepatic Fe loading, hepcidin expression was decreased in TfR2 mutant mice compared with wild-type mice. Even when compared with Fe-loaded wild-type mice, TfR2 mutant mice had increased Fe absorption, increased duodenal Fe transport gene expression, increased liver Fe uptake, and decreased liver hepcidin expression. In conclusion, despite systemic Fe loading, Fe absorption and liver Fe uptake were increased in TfR2 mutant mice in association with decreased expression of hepcidin. These findings support a model in which TfR2 is a sensor of Fe status and regulates duodenal Fe absorption and liver Fe uptake.

Upregulation of lymphotoxin beta expression in liver progenitor (oval) cells in chronic hepatitis C.

BACKGROUND: Bipotent liver progenitor (oval) cells with the ability to differentiate into hepatocytes and biliary epithelium have recently been identified in human subjects with hepatitis C. Animal studies suggest that members of the tumour necrosis factor family, including lymphotoxin beta (LT-beta), regulate oval cell proliferation in liver disease, but its role in human liver disease is unclear. AIMS: This study seeks to establish a role for LT-beta in hepatitis C related liver injury and to provide evidence that its increased expression is related to the presence of oval cells. METHODS: Liver biopsy specimens were obtained from patients with chronic hepatitis C virus (HCV) infection (n=20). Control liver samples (n=5) were obtained from liver resection or transplant surgery. LT-beta expression in liver biopsy specimens was studied using quantitative real time polymerase chain reaction and immunohistochemistry. RESULTS: LT-beta mRNA levels were similar in control and HCV liver in the absence of fibrosis. In subjects with portal fibrosis, LT-beta mRNA levels were elevated 2.2-fold over control liver levels (p=0.04). In subjects with bridging fibrosis, LT-beta mRNA levels increased 4.4-fold over control liver levels (p=0.02). LT-beta mRNA levels in subjects with established cirrhosis were increased 3.3-fold compared with controls and 2.6-fold compared with mild liver damage (p=0.02). Immunohistochemical analysis established that LT-beta was expressed by oval cells, inflammatory cells, and small portal hepatocytes. CONCLUSIONS: In chronic HCV infection, LT-beta expression is observed in multiple hepatic cell types, including oval cells. LT-beta expression is significantly increased when fibrosis or cirrhosis is present, suggesting a role for LT-beta in the pathogenesis of chronic hepatitis C and a possible role in oval cell mediated liver regeneration.

Serum ferritin and cardiovascular disease: a 17-year follow-up study in Busselton, Western Australia.

The association between serum ferritin level and coronary heart disease (CHD) and stroke events was evaluated in a long-term Western Australia prospective study in 1981-1998. The cohort consisted of the 1612 men and women aged 40-89 years who participated in the 1981 Busselton Health Survey and who were free of cardiovascular disease at that time. Serum ferritin levels were obtained from serum samples stored frozen since 1981. The outcomes of interest were time to first CHD event (hospital admission or death) and time to first stroke event. Case-cohort sampling was used to reduce costs and preserve serum but still allow efficient analysis. Ferritin assays were performed for 217 CHD cases, 118 stroke cases, and a random sample of 450 of the total cohort. Proportional hazards regression models were used to obtain age-adjusted and multivariate-adjusted hazard ratios for ferritin level in relation to CHD and stroke. The hazard ratio for the highest tertile group compared with the lowest group was 0.96 (95% confidence interval: 0.60, 1.53) for CHD and 1.43 (95% confidence interval: 0.78, 2.64) for stroke. Little or no evidence was found that ferritin level was a risk factor for cardiovascular disease.

Molecular pathogenesis of iron overload.

Our current understanding of iron absorption under normal conditions is presented, together with an overview of the clinical disorders of iron overload and the molecular processes that contribute to increased iron deposition in iron overload. Recently, a number of new genes involved in iron metabolism have been identified which is allowing the molecular mechanisms of iron absorption to be elucidated.

Hereditary haemochromatosis: detection and management.

Hereditary haemochromatosis is common, affecting one in 200 Australians of Anglo-Celtic descent; it results in iron overload affecting many organs, including the liver, heart, endocrine and musculoskeletal system. Diagnosis requires a high index of suspicion, as presenting symptoms and signs may be non-specific. Once suspected, hereditary haemochromatosis can be readily diagnosed by measurement of serum transferrin saturation and ferritin level, followed by genetic assessment. Homozygosity for the C282Y mutation in the HFE gene accounts for most cases in people of Anglo-Celtic descent in Australia; a genetic test for this mutation is widely available. Liver biopsy is advocated only in selected individuals at risk of cirrhosis or with an unclear diagnosis. Therapeutic phlebotomy remains the treatment and, if instituted early, will prevent many of the organ-specific complications.

High prevalence of coeliac disease in a population-based study from Western Australia: a case for screening?

OBJECTIVES: To determine the prevalence of coeliac disease in an Australian rural community. DESIGN: Retrospective analysis of stored serum samples from 3,011 random subjects from the Busselton Health Study. IgA antiendomysial antibodies (AEA) were detected by indirect immunofluorescence, and subjects testing positive were contacted and offered small-bowel biopsy. MAIN OUTCOME MEASURES: Prevalence of AEA positivity and biopsy-proven coeliac disease in the community with reference to the proportion of symptomatic to asymptomatic patients. RESULTS: 10 of 3,011 subjects were AEA positive. One subject had died, one subject could not be traced and one refused small-bowel biopsy. All subjects with detectable AEA who consented to biopsy had pathological changes consistent with coeliac disease. The prevalence of newly diagnosed biopsyproven coeliac disease is 7 in 3,011 (1 in 430). Two further subjects had a diagnosis of coeliac disease before this study. When all AEA-positive patients and those previously diagnosed are included, the prevalence is 12/3,011 (1 in 251). There was a significant clustering of cases in the 30-50-years age range, with 10/12 (83%; 95% CI, 52%-98%) aged between 30 and 50 years, compared with 1,092/3,011 (36%; 95% CI, 35%-38%) of the total population (P<0.03). Of the eight AEA-positive subjects who could be contacted, four had symptoms consistent with coeliac disease and four were asymptomatic. Three subjects were iron-deficient, four subjects had first-degree relatives with coeliac disease and one subject had type 1 diabetes mellitus. CONCLUSIONS: The prevalence of coeliac disease is high in a rural Australian community. Most patients are undiagnosed, and asymptomatic.