Maternal serum lipids during pregnancy and infant birth weight: the influence of prepregnancy BMI

Maternal obesity may be associated with metabolic factors that affect the intrauterine environment, fetal growth, and the offspring's long-term risk for chronic disease. Among these factors, maternal serum lipids play a particularly important role. Our objective was to estimate the influence of variation in maternal serum lipid levels on variation in infant birth weight (BW) in overweight/obese and normal weight women. In a prospective cohort of 143 gravidas, we measured maternal serum levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG) at 6-10, 10-14, 16-20, 22-26, and 32-36 weeks gestation. Effects of maternal serum lipid levels on infant BW adjusted for gestational age at delivery (aBW) were analyzed using linear regression models. In analyses stratified by maternal prepregnancy BMI categorized as normal (≤25.0 kg/m(2)) and overweight/obese (>25.0 kg/m(2)), we found a significant (P < 0.05) inverse association between aBW and HDL-C at all time points starting at 10 weeks gestation in overweight/obese women. No significant effect was found in normal weight women. In contrast, increased maternal serum TG was significantly associated with increased aBW only for normal weight women at 10-14 and 22-26 weeks gestation. Variation in aBW is not associated with variation in maternal serum TC or LDL-C for either stratum at any time point. We postulate that such differences may be involved in the "physiological programming" that influences later risk of chronic disease in the infants of overweight/obese mothers.

Increasing Prevalence of Primary Biliary Cholangitis and Reduced Mortality With Treatment

BACKGROUND & AIMS

There are few data from longitudinal studies of trends in primary biliary cholangitis (PBC) among patients under routine clinical care in the United States. We collected data from the Fibrotic Liver Disease consortium to investigate changes in the incidence and prevalence of PBC and the effects of patient demographics, clinical features, and treatment on mortality.

METHODS

We collected demographic and clinical data for the general patient population as well as PBC patients receiving care from 11 health systems in different regions of the United States (Northeast, Midwest, Northwest, and South) from January 1, 2003, through December 31, 2014. Annual percentage changes in PBC prevalence and incidence were estimated using join-point Poisson regression. Differences based on race, age, and gender were calculated with rate ratios. All-cause mortality was estimated using Cox regression with adjustment for patient characteristics and treatment with ursodeoxycholic acid (UDCA). Propensity scores were used to adjust for treatment selection bias. Analyses were adjusted by geographic regions.

RESULTS

In our racially diverse cohort of 3488 patients with PBC (21% Hispanic, 8% African American, 7% Asian American), 70% had ever received UDCA. From 2006 through 2014, the prevalence of PBC increased from 21.7 to 39.2 per 100,000 persons. Adjusted annual percentage changes in prevalence differed among age groups (≤40 y, 41-50 y, 51-60 y, 61-70 y, and >70 y), ranging from 3.0% to 7.5% (P < .05). Incidence did not change significantly during the study period (4.2 vs 4.3 per 100,000 person-years in 2006 and 2014, respectively; P = .98). Ratios of prevalence for women vs men (3.9:1) and incidence for women vs men (3.2:1) were consistent over the study period. Among African Americans, the prevalence of PBC increased from 16.9 to 30.8 per 100,000 during the study period, and annual incidence ranged from 2.6 to 6.6 per 100,000 person-years. In adjusted analyses, an increased level of alkaline phosphatase at baseline was associated with significantly higher mortality (adjusted hazard ratios [aHR], 1.24; 95% CI, 1.04-1.48 for patients with levels 1-2 times the upper limit of normal and aHR, 2.27; 95% CI, 1.88-2.73 for patients with levels more than 3 times the upper limit of normal). UDCA treatment was associated with significantly reduced mortality (aHR, 0.57; 95% CI, 0.52-0.64).

CONCLUSIONS

In an analysis of data from patients receiving routine clinical care in Fibrotic Liver Disease Consortium health systems, we found that the prevalence of PBC increased from 2004 through 2014, despite steady incidence. Patient demographic and clinical characteristics, as well as UDCA treatment, affected mortality.

The influence of overweight and obesity on longitudinal trends in maternal serum leptin levels during pregnancy

Maternal obesity influences a number of metabolic factors that can affect the course of pregnancy. Among these factors, leptin plays an important role in energy metabolism and fetal development during pregnancy. Our objective was to estimate the influence of maternal overweight/obesity on variation in the maternal serum leptin profile during pregnancy. In a prospective cohort of 143 adult gravidas with singleton pregnancies presenting for general prenatal care, we measured serum leptin levels at 6-10, 10-14, 16-20, 22-26, and 32-36 weeks' gestation. The longitudinal effects of maternal prepregnancy BMI, categorized as nonoverweight (≤ 26.0 kg/m(2)) and overweight/obese (>26.0 kg/m(2)), on serum leptin concentration were analyzed using linear mixed models. Overweight/obese women had significantly higher serum leptin concentrations than their nonoverweight counterparts throughout pregnancy (P < 0.01). Although these concentrations increased significantly across gestation for both groups, the rate of increase was significantly smaller for overweight/obese women (P < 0.05). To investigate whether these differences merely reflected differences in weight-gain patterns between the two groups, we examined an index of leptin concentration per unit body weight (leptin (ng/ml)/weight (kg)). Overweight/obese women had a significantly higher index throughout pregnancy (P < 0.01). However, although this index increased significantly across pregnancy for nonoverweight women, it actually decreased significantly for overweight/obese women (P < 0.01). Our results suggest that factors other than fat mass alone influence leptin concentrations in overweight/obese women compared to normal-weight women during pregnancy. Such factors may contribute to differences in the intrauterine environment and its influence on pregnancy outcomes in the two groups.

Changes in adipose tissue distribution during pregnancy in overweight and obese compared with normal weight women

OBJECTIVE

Differences in body fat distribution contribute to the metabolic abnormalities associated with overweight and obesity; however, such differences have not been adequately explored during pregnancy. Our aim was to compare longitudinal trends in maternal abdominal adipose tissue deposition during pregnancy in overweight/obese compared with normal weight women.

STUDY DESIGN

Pregnant women, classified as normal weight (body mass index (BMI) <25 kg m(-2); N=61) or overweight/obese (BMI 25 kg m(-2); N=57), were enrolled in a prospective cohort study starting in the first trimester. Maternal subcutaneous (smin) and preperitoneal (pmax) fat were measured by ultrasound at five time points starting between 6 and 10 weeks gestation. The abdominal fat index (AFI), an established marker of visceral adipose tissue, was calculated as the ratio of pmax to smin. The trajectories of smin, pmax, cumulative fat index (smin plus pmax) and the AFI across pregnancy were analyzed using mixed linear models.

RESULTS

The rate of maternal weight gain during pregnancy was significantly lower for overweight/obese women compared with their non-overweight counterparts (P<0.05). Accordingly, the rate of change of pmax and smin differed significantly in normal weight compared with overweight/obese women (P=0.0003 and 0.01, respectively). The cumulative fat index did not change across gestation in normal weight women, whereas it decreased for overweight/obese women (P=0.0005). The log AFI increased across pregnancy in both strata, but significantly more rapidly for normal weight compared with overweight/obese women (P=0.06).

CONCLUSIONS

Adipose tissue is preferentially deposited in the more metabolically active visceral compartment as pregnancy progresses. However, this process differs in normal weight compared with overweight/obese women and may contribute to metabolic differences between these groups. Our study is a step toward a more refined description of obesity and its consequences during pregnancy.

Maternal serum leptin during pregnancy and infant birth weight: the influence of maternal overweight and obesity

OBJECTIVE

Few studies have examined whether the distinct metabolic patterns found in obese and nonobese pregnant women have different effects on the growing fetus. Our objective was to estimate the influence of longitudinal variation in maternal serum leptin levels on variation in infant birth weight in overweight/obese versus normal-weight women.

DESIGN AND METHODS

In a prospective cohort of 286 gravidas, maternal weight and serum leptin levels at 6-10, 10-14, 16-20, 22-26, and 32-36 weeks gestation were measured. Effects of leptin levels on infant birth weight adjusted for gestational age at delivery (aBW) were analyzed using a linear regression model that accounted for the relationship of time-varying predictors to the log-transformed leptin concentrations.

RESULTS

Different relationships of aBW to maternal serum leptin and its rate of change across pregnancy were exhibited by overweight/obese and normal-weight gravidas. For normal-weight women, aBW is not associated with either the magnitude of the logarithm of the leptin concentration or with its rate of change in either the first or second half of pregnancy. Conversely, for overweight/obese women, an increase in the rate of change in maternal serum leptin in the second half of pregnancy is significantly associated with a decrease in aBW. This effect is distinct from that of maternal weight.

CONCLUSION

Differences in the effect of maternal serum leptin on fetal growth between overweight/ obese and normal-weight women suggest metabolic and physiologic heterogeneity between these groups. Such differences may be involved in the long-term physiologic effects of the obese intrauterine environment on the health of the offspring.

Association of ANXA11 genetic variation with sarcoidosis in African Americans and European Americans

A recent genome-wide association study in a German population and two subsequent studies in European populations found that a non-synonymous single-nucleotide polymorphism (SNP), rs1049550, within the annexin A11 (ANXA11) gene was associated with susceptibility to sarcoidosis. We sought to identify additional ANXA11 variants independently associated with sarcoidosis, determine whether any sarcoidosis-associated ANXA11 variants were associated with chest radiographic phenotypes, and explore human leukocyte antigen (HLA) SNP-SNP interactions with ANXA11. A total of 209 SNPs spanning 100 kb including the 5' promoter, coding, and 3' untranslated regions of ANXA11 were genotyped for 1689 sarcoidosis cases and 1252 controls. After adjustment for rs1049550, two additional novel ANXA11 sarcoidosis associations were identified only in African Americans--rs61860052 (odds ratio (OR)=0.62; 95% confidence interval (CI)=0.40-0.97) and rs4377299 (OR=1.31; 95% CI=1.06-1.63). These associations were more pronounced in radiologically-classified Scadding stage IV sarcoidosis cases. We also identified a significant SNP-SNP interaction between rs1049550 and a sarcoidosis risk SNP (rs9268839) near the HLA-DRA locus. This further genetic dissection of ANXA11 may provide additional insight into the immune dysregulation characteristic of sarcoidosis pathophysiology.

Association of HLA-DRB1 with Sarcoidosis Susceptibility and Progression in African Americans

HLA-DRB1 is a sarcoidosis risk gene, and the *03:01 allele is strongly associated with disease resolution in European sarcoidosis cases. Whereas the HLA-DRB1 variation is associated with sarcoidosis susceptibility in African Americans, DRB1 risk alleles are not as well defined, and associations with disease resolution have not been studied. Associations between genotyped and imputed HLA-DRB1 alleles and disease susceptibility/resolution were evaluated in a sample of 1,277 African-American patients with sarcoidosis and 1,467 control subjects. In silico binding assays were performed to assess the functional significance of the associated alleles. Increased disease susceptibility was associated with the HLA-DRB1 alleles *12:01 (odds ratio [OR], 2.11; 95% confidence interval [CI], 1.65-2.69; P = 3.2 × 10(-9)) and *11:01 (OR, 1.69; 95% CI, 1.42-2.01; P = 3.0 × 10(-9)). The strongest protective association was found with *03:01 (OR, 0.56; 95% CI, 0.44-0.73; P = 1.0 × 10(-5)). The African-derived allele *03:02 was associated with decreased risk of persistent radiographic disease (OR, 0.52; 95% CI, 0.37-0.72; P = 1.3 × 10(-4)), a finding consistent across the three component studies comprising the analytic sample. The DRB1*03:01 association with disease persistence was dependent upon local ancestry, with carriers of at least one European allele at DRB1 at a decreased risk of persistent disease (OR, 0.36; 95% CI, 0.14-0.94; P = 0.037). Results of in silico binding analyses showed that DRB1*03:01 consistently demonstrated the highest binding affinities for six bacterial peptides previously found in sarcoidosis granulomas, whereas *12:01 displayed the lowest binding affinities. This study has identified DRB1*03:01 and *03:02 as novel alleles associated with disease susceptibility and course in African Americans. Further investigation of DRB1*03 alleles may uncover immunologic factors that favor sarcoidosis protection and resolution among African Americans.

Sustained virological response to hepatitis C treatment decreases the incidence of complications associated with type 2 diabetes

BACKGROUND

The role of hepatitis C (HCV) eradication on the long-term complications of type 2 diabetes mellitus remains incompletely studied.

AIM

To investigate whether antiviral treatment impacted risk of acute coronary syndrome, end-stage renal disease, ischaemic stroke, and retinopathy among diabetic patients from the four US health systems comprising the Chronic Hepatitis Cohort Study (CHeCS).

METHODS

We included CHeCS HCV patients with diagnosis codes for type 2 diabetes who were on antidiabetic medications. Patients were followed until an outcome of interest, death, or last health system encounter. The effect of treatment on outcomes was estimated using the competing risk analysis (Fine-Gray subdistribution hazard ratio [sHR]), with death as a competing event.

RESULTS

Among 1395 HCV-infected patients with type 2 diabetes, 723 (52%) were treated with either interferon-based or direct-acting antivirals (DAAs); 539 (75% of treated) achieved sustained virological response (SVR). After propensity score adjustment to address treatment selection bias, patients with SVR demonstrated significantly decreased risk of acute coronary syndrome (sHR = 0.36; P < 0.001), end-stage renal disease (sHR = 0.46; P < 0.001), stroke (sHR = 0.34; P < 0.001), and retinopathy (sHR = 0.24; P < 0.001) compared to untreated patients. Results were consistent in subgroup analyses of DAA-treated patients and interferon-treated patients, an analysis of cirrhotic patients, as well as in sensitivity analyses considering cause-specific hazards, exclusion of patients with on-treatment retinopathy, and treatment status as a time-varying covariate.

CONCLUSION

Successful HCV treatment among patients with type 2 diabetes significantly reduces incidence of acute coronary syndrome, end-stage renal disease, ischaemic stroke, and retinopathy, regardless of cirrhosis. Our findings support the importance of HCV antiviral therapy among patients with type 2 diabetes to reduce the risk of these extrahepatic outcomes.

Alcohol-related hepatitis admissions increased 50% in the first months of the COVID-19 pandemic in the USA

Early reports suggest that alcohol misuse increased in 2020 as a result of the COVID-19 pandemic. Using retrospective data from Henry Ford Health System in Detroit MI-an area that experienced an early and severe COVID-19 outbreak-we investigated the impact of the pandemic on alcohol-related liver disease (ARLD) in the summer of 2020 compared with the same period in 2016-2019. Both the number of ARLD admissions and the proportion of total admissions represented by ARLD patients increased significantly in 2020 compared with previous years. The number of ARLD admissions as a proportion of all hospitalizations was 50% higher in 2020 than in 2016-2019 (0.31% vs 0.21%; P = .0013); by September 2020, the number of admissions was 66% higher than previous years. Despite racial and geographical disparities in direct and indirect COVID-related stressors across the Detroit metropolitan area, the demographic profile of ARLD patients did not change compared with previous years.

Elevated polycyclic aromatic hydrocarbon-DNA adducts in benign prostate and risk of prostate cancer in African Americans

Carcinogen-DNA adducts, a marker of DNA damage, are capable of inducing mutations in oncogenes and tumor suppressor genes, resulting in carcinogenesis. We have shown previously that polycyclic aromatic hydrocarbon (PAH)-DNA adduct levels in prostate cancer cases vary by cellular histology and that higher adduct levels are associated with biochemical recurrence. A nested case-control study was conducted in a historical cohort of 6692 men with histopathologically benign prostate specimens. PAH-DNA adduct levels were determined by immunohistochemistry in benign prostate specimens from 536 prostate cancer case-control pairs (59% White and 41% African American). We estimated the overall and race-stratified risk of subsequent prostate cancer associated with higher adduct levels. Prostate cancer risk for men with elevated adduct levels (defined as greater than control group median) was slightly increased [odds ratio (OR) = 1.28, 95% confidence interval (CI) = 0.98-1.67, P = 0.07]. After race stratification, elevated adduct levels were significantly associated with increased risk in African American men (OR = 1.56, CI = 1.00-2.44, *P = 0.05) but not White men (OR = 1.14, CI = 0.82-1.59, P = 0.45). Elevated PAH-DNA adduct levels were significantly associated with 60% increased risk of prostate cancer among cases diagnosed 1-4 years after cohort entry (OR = 1.60, CI = 1.07-2.41) with a greater risk observed in African Americans within the first 4 years of follow-up (OR = 4.71, CI = 1.97-11.26, ***P = 0.0005). Analyses stratified by age or tumor grade revealed no additional significant heterogeneity in risk. Increased prostate cancer risk associated with high PAH-DNA adduct levels in benign prostate was found only in African Americans; risk was greatest within 4 years of follow-up, possibly reflecting a carcinogenic process not yet histologically detectable.

Validity of an automated algorithm using diagnosis and procedure codes to identify decompensated cirrhosis using electronic health records

Viral hepatitis-induced cirrhosis can progress to decompensated cirrhosis. Clinical decompensation represents a milestone event for the patient with cirrhosis, yet there remains uncertainty regarding precisely how to define this important phenomenon. With the development of broader treatment options for cirrhotic hepatitis patients, efficient identification of liver status before evolving to decompensated cirrhosis could be life-saving, but research on the topic has been limited by inconsistencies across studies, populations, and case-confirmation methods. We sought to determine whether diagnosis/procedure codes drawn from electronic health records (EHRs) could be used to identify patients with decompensated cirrhosis. In our first step, chart review was used to determine liver status (compensated cirrhosis, decompensated cirrhosis, non-cirrhotic) in patients from the Chronic Hepatitis Cohort Study. Next, a hybrid approach between Least Absolute Shrinkage and Selection Operator regression and Classification Regression Trees models was used to optimize EHR-based identification of decompensated cirrhosis, based on 41 diagnosis and procedure codes. These models were validated using tenfold cross-validation; method accuracy was evaluated by positive predictive values (PPVs) and area under receiver operating characteristic (AUROC) curves. Among 296 patients (23 with hepatitis B, 268 with hepatitis C, and 5 co-infected) with a 2:1 ratio of biopsy-confirmed cirrhosis to noncirrhosis, chart review identified 127 cases of decompensated cirrhosis (Kappa=0.88). The algorithm of five liver-related conditions—liver transplant, hepatocellular carcinoma, esophageal varices complications/procedures, ascites, and cirrhosis—yielded a PPV of 85% and an AUROC of 92%. A hierarchical subset of three conditions (hepatocellular carcinoma, ascites, and esophageal varices) demonstrated a PPV of 81% and an AUROC of 86%. Given the excellent predictive ability of our model, this EHR-based automated algorithm may be used to successfully identify patients with decompensated cirrhosis. This algorithm may contribute to timely identification and treatment of viral hepatitis patients who have progressed to decompensated cirrhosis.

Methylation of the RARB gene increases prostate cancer risk in black Americans

PURPOSE

Gene promoter hypermethylation may be useful as a biomarker for cancer risk in histopathologically benign prostate specimens.

MATERIALS AND METHODS

We performed a nested case-control study of gene promoter methylation status for 5 genes (APC, RARB, CCND2, RASSF1 and MGMT) measured in benign biopsy specimens from 511 prostate cancer case-control pairs. We estimated the overall and race stratified risk of subsequent prostate cancer associated with methylation status.

RESULTS

On race stratified analysis RARB methylation was associated with a higher cancer risk in black American men (OR 2.18, 95% CI 1.39-3.44). APC methylation was associated with an increased risk of high grade tumors (OR 2.43, 95% CI 1.20-4.90), which was higher in black than in white men (OR 3.21 vs 2.04). In cases RARB and APC gene methylation in benign prostate samples persisted in matched malignant specimens. In black cases the combined risk associated with RARB and APC methylation (OR 3.04, 95% CI 1.44-6.42) was greater than the individual risk of each gene and significantly different from that in white cases (OR 1.14, 95% CI 0.56-2.30).

CONCLUSIONS

RARB gene methylation in histopathologically benign prostate samples was associated with a statistically significant increased risk of subsequent prostate cancer in black men. Methylation data on additional genes may improve risk stratification and clinical decision making algorithms for cancer screening and diagnosis.

Hepatitis C treatment failure is associated with increased risk of hepatocellular carcinoma

Sustained virological response (SVR) to antiviral therapy for hepatitis C (HCV) reduces risk of hepatocellular carcinoma (HCC), but there is little information regarding how treatment failure (TF) compares to lack of treatment. We evaluated the impact of treatment status on risk of HCC using data from the Chronic Hepatitis Cohort Study (CHeCS-an observational study based in four large US health systems, with up to 7 years of follow-up on patients). Multivariable analyses were used to adjust for bias in treatment selection, as well as other covariates, followed by sensitivity analyses. Among 10 091 HCV patients, 3681 (36%) received treatment, 2099 (57%) experienced treatment failure (TF), and 1582 (43%) of these achieved sustained virological response (SVR). TF patients demonstrated almost twice the risk of HCC than untreated patients [adjusted hazard ratio (aHR) = 1.95, 95% confidence interval (CI) 1.50-2.53]; this risk persisted across all stages of fibrosis. Several sensitivity analyses validated these results. Although African Americans were at increased risk of treatment failure, they were at lower risk for HCC and all-cause mortality compared to White patients. SVR patients had lower risk of HCC than TF patients (aHR = 0.48, CI 0.31-0.73), whereas treatment - regardless of outcome - reduced all-cause mortality (aHR = 0.45, CI 0.34-0.60 for SVR patients; aHR = 0.78, CI 0.65-0.93 for TF patients).

Adjuvant ribavirin and longer direct-acting antiviral treatment duration improve sustained virological response among hepatitis C patients at risk of treatment failure

The role of ribavirin (RBV) in the era of direct-acting antivirals (DAA) is not clear, and DAA studies have been largely genotype- and regimen-specific. Using data from the Chronic Hepatitis Cohort Study, we evaluated the role of RBV and increased DAA treatment duration among patients with chronic hepatitis C (HCV) in routine clinical care. We performed multivariable analysis of data from 4133 patients receiving any of the following: sofosbuvir (SOF); daclatasvir + SOF; grazoprevir + elbasvir; paritaprevir/ritonavir + ombitasvir; simeprevir + SOF; and SOF + ledipasvir; SOF + velpatasvir ± voxilaprevir; and glecaprevir + pibrentasvir-all with/ without RBV. Inverse probability treatment weighting was used to adjust for treatment selection bias. Sustained virological response (SVR) was defined by undetectable HCV RNA 12 weeks after end of therapy. The overall SVR rate was 95%. Mean treatment duration was 12 ± 4.5 weeks. The final model included treatment duration and diabetes, as well as the interaction of RBV with previous treatment status (treatment naïve, interferon treatment failure [TF] or previous DAA TF), cirrhosis status, and HCV genotype (GT). Each one-month increment of treatment duration increased odds of SVR by 99% (aOR = 1.99). Diabetes, previous DAA TF, and decompensated cirrhosis significantly reduced odds of SVR. RBV significantly increased the likelihood of SVR among patients with decompensated cirrhosis (aOR = 5.05), previous DAA treatment failure (aOR = 5.43), and GT3 (aOR = 13.28). Among RBV-free regimens, patients with GT3 were less likely to achieve SVR than those with GT1 or 2 (aOR 0.07). Diabetes, decompensated cirrhosis, and prior DAA TF independently reduced the likelihood of SVR. Longer treatment duration increased likelihood of SVR. Conclusion: RBV increased likelihood of SVR among patients with GT3, previous DAA TF, or decompensated cirrhosis.

Impact of sustained virologic response on risk of type 2 diabetes among hepatitis C patients in the United States

Data regarding the impact of hepatitis C (HCV) therapy on incidence of type 2 diabetes mellitus are limited. We used the data from the longitudinal Chronic Hepatitis Cohort Study-drawn from four large US health systems-to investigate how response to HCV treatment impacts the risk of subsequent diabetes. Among HCV patients without a history of type 2 diabetes mellitus or hepatitis B, we investigated the incidence of type 2 diabetes from 12 weeks post-HCV treatment through December 2015. Cox proportional hazards models were used to test the effect of treatment status (sustained virologic response [SVR] or treatment failure) and baseline risk factors on the development of diabetes, considering any possible risk factor-by-SVR interactions, and death as a competing risk. Among 5127 patients with an average follow-up of 3.7 years, diabetes incidence was significantly lower among patients who achieved SVR (231/3748; 6.2%) than among patients with treatment failure (299/1379; 21.7%; adjusted hazard ratio [aHR] = 0.79; 95% CI: 0.65-0.96). Risk of diabetes was higher among African American and Asian American patients than White patients (aHR = 1.82 and 1.75, respectively; P < .05), and among Hispanic patients than non-Hispanics (aHR = 1.86). Patients with BMI ≥ 30 and 25-30 (demonstrated higher risk of diabetes aHR = 3.62 and 1.72, respectively; P < .05) than those with BMI < 25; patients with cirrhosis at baseline had higher risk than those without cirrhosis (aHR = 1.47). Among a large US cohort of patients treated for HCV, patients who achieved SVR demonstrated a substantially lower risk for the development of type 2 diabetes mellitus than patients with treatment failure.

Performance of HLA allele prediction methods in African Americans for class II genes HLA-DRB1, -DQB1, and -DPB1

Background

The expense of human leukocyte antigen (HLA) allele genotyping has motivated the development of imputation methods that use dense single nucleotide polymorphism (SNP) genotype data and the region’s haplotype structure, but the performance of these methods in admixed populations (such as African Americans) has not been adequately evaluated. We compared genotype-based—derived from both genome-wide genotyping and targeted sequencing—imputation results to existing allele data for HLA–DRB1, −DQB1, and –DPB1.

Results

In European Americans, the newly-developed HLA Genotype Imputation with Attribute Bagging (HIBAG) method outperformed HLA*IMP:02. In African Americans, HLA*IMP:02 performed marginally better than HIBAG pre-built models, but HIBAG models constructed using a portion of our African American sample with both SNP genotyping and four-digit HLA class II allele typing had consistently higher accuracy than HLA*IMP:02. However, HIBAG was significantly less accurate in individuals heterozygous for local ancestry (p ≤0.04). Accuracy improved in models with equal numbers of African and European chromosomes. Variants added by targeted sequencing and SNP imputation further improved both imputation accuracy and the proportion of high quality calls.

Conclusion

Combining the HIBAG approach with local ancestry and dense variant data can produce highly-accurate HLA class II allele imputation in African Americans.

Towards molecular understanding of species differences in dioxin sensitivity: initial characterization of Ah receptor cDNAs in birds and an amphibian

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and related planar halogenated aromatic hydrocarbons (PHAHs) are highly toxic to most vertebrate animals, but there are dramatic species differences in sensitivity, both within and among vertebrate classes. For example, studies in cultured avian hepatocytes have revealed differential sensitivity of birds to PHAHs [Kennedy et al. (1996). Toxicol. Appl. Pharmacol., 141, 214-230]. Differences in the characteristics or expression of the aryl hydrocarbon receptor (AHR) could contribute to these species differences in PHAH responsiveness. To investigate the molecular mechanism of differential PHAH sensitivity, we have begun to characterize the AHR in white leghorn chicken (Gallus gallus), Pekin duck (Anas platyrhynchos), and common tern (Sterna hirundo), as well as an amphibian, mudpuppy (Necturus maculosus). Partial AHR cDNAs encompassing the helix-loop-helix and PAS domains were cloned and sequenced. Comparison of amino acid sequences in this region indicated a high degree of sequence conservation among the bird species (97% amino acid identity). The percent identity between bird sequences and either mouse or mudpuppy was lower (79%); the mudpuppy AHR was 74% identical to the mouse AHR. Phylogenetic analysis of these and other AHR amino acid sequences showed that the bird and mudpuppy AHRs were more closely related to mammalian and fish AHR1 forms than to fish AHR2. Future studies include the in vitro expression and functional characterization of AHRs from these and other non-mammalian vertebrates.

Racial differences in the relationship between clinical prostatitis, presence of inflammation in benign prostate and subsequent risk of prostate cancer

BACKGROUND

Epidemiologic studies, primarily done in white men, suggest that a history of clinically-diagnosed prostatitis increases prostate cancer risk, but that histological prostate inflammation decreases risk. The relationship between a clinical history of prostatitis and histologic inflammation in terms of how these two manifestations of prostatic inflammation jointly contribute to prostate cancer risk and whether racial differences exist in this relationship is uncertain.

METHODS

Using a nested design within a cohort of men with benign prostate tissue specimens, we analyzed the data on both clinically-diagnosed prostatitis (NIH categories I-III) and histological inflammation in 574 prostate cancer case-control pairs (345 white, 229 African American).

RESULTS

Clinical prostatitis was not associated with increased prostate cancer risk in the full sample, but showed a suggestive inverse association with prostate cancer in African Americans (odds ratio (OR)=0.47; 95% confidence interval (CI)=0.27-0.81). In whites, clinical prostatitis increased risk by 40%, but was only associated with a significant increased prostate cancer risk in the absence of evidence of histological inflammation (OR=3.56; 95% CI=1.15-10.99). Moreover, PSA velocity (P=0.008) and frequency of PSA testing (P=0.003) were significant modifiers of risk. Clinical prostatitis increased risk of prostate cancer almost three-fold (OR=2.97; 95% CI=1.40-6.30) in white men with low PSA velocity and about twofold in white men with more frequent PSA testing (OR=1.91; 95% CI=1.09-3.35).

CONCLUSIONS

In our cohort of men with benign prostate specimens, race, and histological inflammation were important cofactors in the relationship between clinical prostatitis and prostate cancer. Clinical prostatitis was associated with a slightly decreased risk for prostate cancer in African American men. In white men, the relationship between clinical prostatitis and prostate cancer risk was modified by histological prostatic inflammation, PSA velocity, and frequency of PSA testing-suggesting a complex interplay between these indications of prostatic inflammation and prostate cancer detection.

Sustained virological response does not improve long-term glycaemic control in patients with type 2 diabetes and chronic hepatitis C

BACKGROUND

Sustained virological response to treatment for chronic hepatitis C virus may improve short-term glucose control among patients with type 2 diabetes, but the long-term impact remains largely unknown. We used data from the Chronic Hepatitis Cohort Study to investigate the impact of sustained virological response on long-term trends in haemoglobin A1c in patients with type 2 diabetes.

METHODS

"Index date" was defined as the date of treatment initiation (treated patients) or hepatitis C virus diagnosis (untreated patients). To address treatment selection bias, we used a propensity score approach. We used a piecewise, linear spline, mixed-effects model to evaluate changes in haemoglobin A1c over a 5-year period.

RESULTS

Our sample included 384 hepatitis C virus patients with type 2 diabetes (192 untreated, 192 treated, with sustained virological response or treatment failure). After adjusting for body mass index, haemoglobin A1c was stable among untreated and treatment failure patients. In sustained virological response patients, Hb1Ac trajectories evolved in three phases: (a) index through 6 months post-index, average haemoglobin A1c decreased significantly from 7.7% to 5.4% per 90 days (P < 0.001); (b) 6-30 months post-index, haemoglobin A1c rebounded at a rate of 1.5% every 90 days (P = 0.003); and (c) from 30 months onward, haemoglobin A1c stabilized at an average level of 7.9 (P-value = 0.34). Results from an analysis restricted to patients receiving direct-acting antivirals were consistent with the main findings.

CONCLUSION

Successful hepatitis C virus treatment among patients with type 2 diabetes significantly reduces HbA1c shortly after treatment, but these decreases are not sustained long-term. Less than three years after sustained virological response, haemoglobin A1c rebounds to levels similar to untreated/treatment failure patients, and higher than recommended for type 2 diabetic maintenance.

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)-DNA adducts in benign prostate and subsequent risk for prostate cancer

Despite convincing evidence that 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)--a heterocyclic amine generated by cooking meats at high temperatures--is carcinogenic in animal models, it remains unclear whether PhIP exposure leads to increased cancer risk in humans. PhIP-DNA adduct levels were measured in specimens from 534 prostate cancer case-control pairs nested within a historical cohort of men with histopathologically benign prostate specimens. We estimated the overall and race-stratified risk of subsequent prostate cancer associated with higher adduct levels. PhIP-DNA adduct levels in benign prostate were significantly higher in Whites than African Americans (0.274 optical density units (OD) ±0.059 vs. 0.256 OD ±0.054; p<0.0001). Prostate cancer risk for men in the highest quartile of PhIP-DNA adduct levels was modestly increased [odds ratio (OR) = 1.25; 95% confidence interval (CI) = 0.76-2.07]. In subset analyses, the highest risk estimates were observed in White patients diagnosed more than 4 years after cohort entry (OR = 2.74; 95% CI = 1.01-7.42) or under age 65 (OR = 2.80; 95% CI = 0.87-8.97). In Whites, cancer risk associated with high-grade prostatic intraepithelial neoplasia combined with elevated PhIP-DNA adduct levels (OR = 3.89; 95% CI = 1.56-9.73) was greater than risk associated with either factor alone. Overall, elevated levels of PhIP-DNA adducts do not significantly increase prostate cancer risk. However, our data show that White men have higher PhIP-DNA adduct levels in benign prostate tissue than African American men, and suggest that in certain subgroups of White men high PhIP-DNA adduct levels may predispose to an increased risk for prostate cancer.

Organochlorines and possible biochemical effects in glaucous gulls (Larus hyperboreus) from Bjørnøya, the Barents Sea

To study possible biochemical effects of organochlorine contaminants (OCs) in glaucous gulls (Larus hyperboreus), 40 adult individuals were collected from colonies on Bjornoya in the Barents Sea. OCs (four pesticides and nine PCB congeners), microsomal 7-ethoxyresorufin O-deethylase (EROD) activity, microsomal testosterone hydroxylation, highly carboxylated porphyrins (HCPs), retinol, and retinyl palmitate were quantified in liver samples. The hepatic vitamin A stores in glaucous gulls were larger than in herring gulls (Larus argentatus) from other studies conducted in contaminated locations in North America. No significant relationships were found between liver retinoid concentrations and OC levels. The hepatic EROD activity was low compared to other studies on fish-eating birds and only marginally associated with PCB levels. Microsomal testosterone hydroxylase activity was only observed at the 6beta-position and could not be related to OC levels. The low P450-associated enzyme activities in the glaucous gull suggests that they have a low capacity for metabolizing OCs, which may contribute to the high accumulation of OCs in this species. HCPs were only elevated (138 pmol g(-1)) in the sample with highest OC levels, whereas the remaining samples contained low levels of HCPs (<30 pmol g(-1)). The weak association between EROD activity and PCB levels and the low level of HCPs suggest that these biochemical parameters were unaffected by OCs in most of the sampled gulls. Thus, the glaucous gull seems not to be particularly sensitive toward Ah-receptor mediated effects.

A cellular basis for high levels of vitamin A in livers of polar bears (Ursus maritimus): the Ito cell

Numerous large perisinusoidal cells containing prominent cytoplasmic lipid droplets were observed in the livers of adult and subadult polar bears (Ursus maritimus). The cells were identified as Ito cells by histological, histochemical, and ultrastructural criteria. The ratio of Ito cell to hepatocyte numbers in three bears was 1:5.6, much higher than that reported in humans. Total liver retinol and retinol palmitate in three livers correlated well with mean Ito cell area (r = 0.98). We postulate that the large number and size of Ito cells in polar bear livers is an adaptation to high dietary levels of vitamin A.

Using dried blood spots stored on filter paper to measure cholinesterase activity in wild avian species

Birds of prey that are poisoned by cholinesterase inhibitors (e.g. organophosphate and carbamate insecticides) are often cared for at animal shelters, rehabilitation centres and wildlife diagnostic facilities. Plasma cholinesterase (ChE) activity is a recognized method of assessing exposure to these insecticides, but standard blood-handling protocols are difficult to follow in non-laboratory settings. The primary objective of this study was to expand upon a method for storing human blood on filter paper without the need for complicated equipment or refrigeration, and to test its utility for measurement of ChE activity in avian blood. ChE activity from whole blood, plasma, and dried blood spots was analysed from 169 wild birds and comparisons made among sample types. ChE activity measured in whole blood haemolysates and dried blood spots were significantly correlated (r = 0.74, p < 0.001), as was ChE activity measured in plasma and dried blood spots (r = 0.68, p < 0.001). This study demonstrated that monitoring pesticide exposure in birds could be conducted using elementary blood sampling, preserving and shipping techniques.

Experimental vitamin A deficiency in mallards (Anas platyrhynchos): lesions and tissue vitamin A levels

Captive mallards (Anas platyrhynchos), fed an all-grain diet for up to 5 months during the winters of 1991 to 1992 and 1992 to 1993, developed lesions of squamous metaplasia; some had no detectable hepatic vitamin A. Vitamin A deficiency in mallards was defined as hepatic levels of retinyl palmitate < 2 micrograms/g liver. Lesions were found only in ducks with low levels of hepatic vitamin A, but not all ducks with these low levels of hepatic vitamin A had histological lesions. The prevalence of lesions in the esophagus was greatest cranially and caudally and less common in the central region. Palatine salivary glands rarely were affected. Mallards with liver stores > 600 micrograms of hepatic retinyl palmitate per g liver, fed a diet deficient in vitamin A were unlikely to become deficient over a 5 month period. Birds fed an all-grain diet had significantly lower vitamin A concentrations in their liver compared to those fed an all-grain diet with vitamin A added. Liver weight, when corrected for body size, did not affect vitamin A concentration. Serum retinol levels were conserved over a large range of hepatic vitamin A levels but levels below 300 micrograms retinol/l were useful in detecting vitamin A deficiency in captive mallards. Based on the findings, the presence of lesions provides a conservative measure of vitamin A status in ducks and tissue levels should be measured in instances when mallards have questionable vitamin A status.