Ferroportin (Q248H) mutations in African families with dietary iron overload

BACKGROUND: Dietary iron overload found in sub-Saharan Africa might be caused by an interaction between dietary iron and an iron-loading gene. Caucasian people with ferroportin gene mutations have iron overload histologically similar to that found in African patients with iron overload. Ferroportin is also implicated in the hypoferremic response to inflammation. The prevalence of the ferroportin Q248H mutation, unique to African people, and its association with dietary iron overload, mean cell volume (MCV) and C-reactive protein (CRP) were examined in 19 southern African families. METHODS: Polymerase chain reaction (PCR) and restriction enzyme digestion were used to identify the Q248H mutation. Statistical analysis was carried out to correlate the presence of the mutation with markers of iron overload and inflammation. RESULTS: We identified three (1.4%) Q248H homozygotes and 53 (24.1%) heterozygotes in the families examined in the present study. There was no increased prevalence of the mutation in index subjects or their families. Logistic regression showed significantly higher serum ferritin concentrations with the mutation. The mean cell volume (MCV) was significantly lower, and the serum CRP significantly higher in subjects who carried the mutation. CONCLUSIONS: The present study of 19 families with African iron overload failed to show evidence that the ferroportin (Q248H) mutation is responsible for the condition. Logistic regression, correcting for factors influencing iron status, did show increased ferritin levels in individuals with the mutation. The strong association with low MCV suggests the possibility that the ferroportin (Q248H) mutation might interfere with iron supply, whereas the elevated serum CRP might indicate that the ferroportin mutation influences the inflammatory response in African populations.     

Reduced sensitivity of the ferroportin Q248H mutant to physiological concentrations of hepcidin

Ferroportin Q248H mutation has an allele frequency of 2.2–13.4% in African populations and is associated with a mild tendency to increased serum ferritin in the general population. Some investigators have reported that ferroportin Q248H is degraded after exposure to hepcidin in exactly the same manner as wild-type ferroportin, but supraphysiological concentrations of hepcidin were used. The aim of our study was to determine whether ferroportin Q248H may have reduced sensitivity to physiological concentrations of hepcidin. The sensitivity of ferroportin Q248H to hepcidin was determined in 293T cells transiently expressing ferroportin using immunoblotting and fluorescence analysis. Ferritin concentrations were measured in these cells and also in human primary monocytes derived from humans with different ferroportin genotypes. The effect of Q248H on serum iron measures was examined in patients with sickle cell anemia. Immunoblotting and fluorescence analysis showed decreased sensitivity of ferroportin Q248H to physiological concentrations of hepcidin. Lower ferritin concentrations were observed after incubation with iron and hepcidin in 293T cells expressing ferroportin Q248H and in primary monocytes from ferroportin Q248H subjects. In sickle cell anemia, ferroportin Q248H heterozygotes had lower serum ferritin concentrations than wild-type subjects, consistent with enhanced iron release by macrophage ferroportin Q248H. A clinical benefit of ferroportin Q248H was suggested by lower echocardiographic estimates of pulmonary artery pressure in patients carrying mutant alleles. In conclusion, our results suggest that ferroportin Q248H protein is resistant to physiological concentrations of hepcidin and that this mutation has discernible effects on iron metabolism-related clinical complications of sickle cell anemia. They provide a mechanistic explanation for the effect of ferroportin Q248H on iron status in individuals of African descent and suggest that these changes in iron metabolism may be beneficial under certain disease-specific circumstances.(ClinicalTrials.gov Identifier:{"type":"clinical-trial","attrs":{"text":"NCT00011648","term_id":"NCT00011648"}}NCT00011648).     

Iron overload in Africans and African-Americans and a common mutation in the SCL40A1 (ferroportin 1) gene

The product of the SLC40A1 gene, ferroportin 1, is a main iron export protein. Pathogenic mutations in ferroportin 1 lead to an autosomal dominant hereditary iron overload syndrome characterized by high serum ferritin concentration, normal transferrin saturation, iron accumulation predominantly in macrophages, and marginal anemia. Iron overload occurs in both the African and the African-American populations, but a possible genetic basis has not been established. We analyzed the ferroportin 1 gene in 19 unrelated patients from southern Africa (N = 15) and the United States (N = 4) presenting with primary iron overload. We found a new c. 744 C-->T (Q248H) mutation in the SLC40A1 gene in 4 of these patients (3 Africans and 1 African-American). Among 22 first degree family members, 10 of whom were Q248H heterozygotes, the mutation was associated with a trend to higher serum ferritin to amino aspartate transferase ratios (means of 14.8 versus 4.3 microg/U; P = 0.1) and lower hemoglobin concentrations (means of 11.8 versus 13.2 g/dL; P = 0.1). The ratio corrects serum ferritin concentration for alcohol-induced hepatocellular damage. We also found heterozygosity for the Q248H mutation in 7 of 51 (14%) southern African community control participants selected because they had a serum ferritin concentration below 400 microg/L and in 5 of 100 (5%) anonymous African-Americans, but we did not find the change in 300 Caucasians with normal iron status and 25 Caucasians with non-HFE iron overload. The hemoglobin concentration was significantly lower in the African community controls with the Q248H mutation than in those without it. We conclude that the Q248H mutation is a common polymorphism in the ferroportin 1 gene in African populations that may be associated with mild anemia and a tendency to iron loading.     

Ferroportin (SLC40A1) Q248H mutation is associated with lower circulating serum hepcidin levels in Rwandese HIV-positive women

The Q248H mutation in the gene SLC40A1 which encodes for the cellular iron exporter ferroportin is relatively common in Africa. This mutation has been associated with resistance to hepcidin and therefore we hypothesized that iron-related parameters and the prevalence of opportunistic infections in HIV might be influenced by the Q248H mutation. We conducted a cross-sectional study among 200 HIV-positive women in the Butare University Teaching Hospital in Rwanda. Polymerase chain reaction (PCR) and restriction enzyme digestion were used to identify the Q248H mutation. Physical examination was carried out and WHO HIV disease stage classification, complete blood count, CD4 count, indirect measures of iron status, serum hepcidin, and C-reactive protein concentrations were determined. The prevalence of ferroportin Q248H mutation was 6%. Subjects with ferroportin Q248H mutation had significantly higher values for serum ferritin (P = 0.001) and significantly lower values for serum hepcidin (P = 0.001) and transferrin (P = 0.01). Among the 12 HIV + Q248H heterozygotes, 8 suffered from at least one opportunistic infection. There was significantly higher prevalence of pulmonary TB (P = 0.01) and Pneumocystis jiroveci pneumonia (P = 0.02) in subjects with ferroportin Q248H mutation. Low hepcidin levels were found in ferroportin Q248H heterozygotes with HIV infection, notwithstanding the absence of anemia and the higher prevalence of some opportunistic infections. Hepcidin seems to be regulated in a different way in Q248H heterozygotes than is known thus far.     

Genotypic and phenotypic heterogeneity of African Americans with primary iron overload

Primary iron overload may be relatively common in African Americans, but its cause is incompletely understood. Thus, we evaluated genotype and phenotype characteristics of unselected African American index patients with primary iron overload who reside in central Alabama. All had hepatic iron concentration > or =30 micromol/g dry wt or > or =2.0 g of iron mobilized by phlebotomy to achieve iron depletion. Genotype analyses were performed in African American control subjects from the same region. There were 23 patients (19 men, 4 women); mean age at diagnosis was 52 +/- 12 years (1 SD) (range 32-69 years). Nine (39.1%) reported that they consumed > or =45 g of ethanol daily; five had chronic hepatitis C. Eight had some form of hemoglobinopathy or thalassemia. Mean serum transferrin saturation was 56 +/- 28% (range 15-100%). The geometric mean serum ferritin at diagnosis was 1076 ng/mL [95% confidence interval 297-3473 ng/mL]. Increased stainable liver iron was observed in hepatocytes only in 4 patients, in macrophages only in 8 patients, and in hepatocytes and macrophages in 8 patients. The mean quantity of iron mobilized by phlebotomy (corrected for iron absorbed during treatment) was 5.3 +/- 2.0 g (range 4.0-8.4 g). Iron removed by phlebotomy was greater in patients with hemoglobinopathy or thalassemia than in those without these forms of anemia (6.6 +/- 1.3 g vs 3.9 +/- 1.6 g, respectively; P = 0.0144). Daily consumption of > or =45 g of ethanol or chronic hepatitis C was not associated with an increased or decreased amount of phlebotomy-mobilized iron, on the average. The percentage of index patients positive for HFE C282Y was greater than that of controls (P = 0.0058). The respective percentages of phenotype positivity for HFE H63D, D6S105(8), and HLA-A*03 were similar in patients and controls. HFE S65C, I105T, and G93R were not detected in index or control subjects. Two of 13 patients were heterozygous for the ferroportin allele nt 744 G-->T (Q248H), although the phenotype frequency of this allele was similar in patients and 39 controls. Synonymous ferroportin alleles were also detected in some patients. The ceruloplasmin mutation nt 1099C-->T (exon 6; Arg367Cys) was detected in 1 of 2 patients tested. Abnormal alleles of beta-2 microglobulin, Nramp2, TFR2, hepcidin, or IRP2 alleles were not detected in either of the 2 patients so tested. We conclude that primary iron overload in African Americans is not the result of the mutation of a single gene. HFE C282Y, ferroportin 744 G-->T, and common forms of heritable anemia appear to account for increased iron absorption or retention in some patients.     

SLC40A1 Q248H allele frequencies and Q248H-associated risk of non-HFE iron overload in persons of sub-Saharan African descent

The ferroportin polymorphism SLC40A1 Q248H (exon 6, cDNA 744G-->T; Gln248His) occurs in persons of sub-Saharan African descent with and without iron overload, and is associated with elevated serum ferritin concentrations (SF). However, the risk of iron overload associated with Q248H has not been defined. We tabulated previously reported Q248H allele frequency estimates in African-Americans and Native Africans, and computed the risk of iron overload associated with Q248H in subjects who lacked HFE C282Y. The aggregate Q248H allele frequency in 1038 African-Americans in two cohorts from Alabama and one cohort each from Washington, DC and California was 0.0525 (95% CI: 0.0451, 0.0652); there was no significant difference in frequencies across these cohorts. The aggregate frequency in 259 Natives from southeast Africa in two cohorts was 0.0946 (95% CI: 0.0694, 0.1198); the difference between the frequencies of these cohorts was not significant. The aggregate Q248H frequencies in African-Americans and Native Africans differed significantly (0.0525 vs. 0.0946, respectively; p=0.0021). There were reports of 24 unrelated African-Americans and 15 unrelated Native Africans without HFE C282Y who had iron overload. In African-Americans, the odds ratio (OR) of Q248H-associated risk of iron overload using 610 C282Y-negative control subjects unselected for SF was 1.57 (95% CI: 0.52, 4.72; p=0.29). In Native Africans, the OR using 208 control subjects unselected for SF was 1.05 (95% CI: 0.28, 3.90; p=0.58). We conclude that the frequency of SLC40A1 Q248H is significantly lower in African-Americans than in Native Africans. Although OR estimates of iron overload in African-Americans and Native Africans with Q248H were greater than unity, the increased OR were not statistically significant.     

Ferroportin Q248H mutation,hyperferritinemia and atypical type 2 diabetes mellitus in South Kivu

BackgroundThe ferroportin Q248H mutation is relatively common in sub-Saharan Africa. No previous study examined its relationship with atypical diabetes mellitus (DM) in this area.ObjectiveTo determine the potential interactions between ferroportin Q248H mutation, hyperferritinemia and DM in South Kivu (RDC).MethodologyPresence of ferroportin Q248H mutation and iron status were investigated in diabetic patients (n = 179, age (mean) 57.7 years, CRP (median) 0.16 mg/L) and non-diabetic subjects (n = 86, age 44.5 years, CRP 0.07 mg/L) living in the city of Bukavu. Hyperferritinemia was considered for values greater than 200 and 300 μg/L in women and in men, respectively.ResultsThe prevalence of ferroportin Q248H mutation [12.1%] was non-significantly higher in diabetics than non-diabetics [14.0% vs. 8.1%, p = 0.17]. Similarly, hyperferritinemia frequency was higher in diabetic patients with Q248H mutation [44.0% vs. 14.3%, p = 0.16] and in mutation carriers [37.0% vs 16.5%, p = 0.001] than in the control groups, respectively. The association between Q248H mutation and DM was nevertheless not significant [adjusted OR 1.70 (95% CI: 0.52–5.58), p = 0.37], whereas hyperferritinemia [OR 2.72 (1.24–5.98), p = 0.01] showed an independent effect after adjustment for age and metabolic syndrome.ConclusionsThe present work suggests a potential association between abnormal iron metabolism, ferroportin Q248H mutation and atypical DM in Africans, which may be modulated by environmental factors.     

Association of ferroportin Q248H polymorphism with elevated levels of serum ferritin in African Americans in the Hemochromatosis and Iron Overload Screening (HEIRS) Study

The ferroportin (FPN1) Q248H polymorphism has been associated with increased serum ferritin (SF) levels in sub-Saharan Africans and in African Americans (AA). AA participants of the HEIRS Study who did not have HFE C282Y or H63D who had elevated initial screening SF (> or =300 microg/L in men and >= or =200 microg/L in women) (defined as cases) were frequency-matched to AA participants with normal SF (defined as controls) to investigate the association of the Q248H with elevated SF. 10.4% of cases and 6.7% of controls were Q248H heterozygotes (P=0.257). Q248H homozygosity was observed in 0.5% of the cases and none of the controls. The frequency of Q248H was higher among men with elevated SF than among control men (P=0.047); corresponding differences were not observed among women. This appeared to be unrelated to self-reports of a previous diagnosis of liver disease. Men with elevated SF were three times more likely than women with elevated SF to have Q248H (P=0.012). There were no significant differences in Q248H frequencies in men and women control participants. We conclude that the frequency of the FPN1 Q248H polymorphism is greater in AA men with elevated SF than in those with normal SF.     

Hepatitis C infection in African Americans: its natural history and histological progression

OBJECTIVE: The aim of this retrospective analysis was to determine the natural history of hepatitis C virus infection in African Americans versus non-African Americans by evaluating the clinical, virological, and histological findings. METHODS: We examined in a retrospective manner the demographics, mode of infection, virological features, and histological progression of HCV infection in African Americans versus non-African Americans. There were 355 patients who met criteria based on adequate liver biopsy specimens and exclusion of other hepatic diseases. RESULTS: African Americans (n = 112) were significantly more likely to be infected with genotype 1 virus (88%) than were non-African Americans (n = 243; 67%; p < or = 0.001). Baseline HCV RNA levels were similar, although baseline ALT values were significantly lower in African Americans (80.0 microl +/- 5.5 vs 112.1 microl +/- 6.2; p < or = 0.001). African Americans were significantly older at the time of presentation and were significantly more likely to be women (p < or = 0.02). In African Americans, there was a trend toward less cirrhosis (22% vs 30%; p < or = 0.1) and significantly less piecemeal necrosis on liver biopsy. Non-African Americans had significantly higher fibrosis scores, ALT values, and piecemeal necrosis ratings, and tended to progress more rapidly to cirrhosis. This difference in histological progression between the two groups was not explained by differences in alcohol consumption. CONCLUSION: The lower ALT, piecemeal necrosis scores, and slower progression of fibrosis in African Americans may reflect less immunological recognition of HCV-infected liver cells.     

The effect of caffeine and alcohol consumption on liver fibrosis – a study of 1045 Asian hepatitis B patients using transient elastography

Background: Role of caffeine consumption in chronic hepatitis B virus (HBV)‐infected patients and the interaction with alcohol consumption is unclear. Aim: This study aimed to investigate the relationship between caffeine and alcohol consumption and liver stiffness in chronic HBV‐infected patients. Methods: Chronic HBV‐infected patients who underwent transient elastography examination in 2006–2008 were studied. Advanced fibrosis was defined as liver stiffness >9 kPa for patients with normal alanine aminotransferase (ALT) or >12 kPa for those with elevated ALT according to previous validation study. Caffeine and alcohol consumption was recorded using a standardized questionnaire. Excessive alcohol intake was defined as 30 g/day in men and 20 g/day in women. Results: The liver stiffness of 1045 patients who completed the questionnaire was 8.3 ± 6.2 kPa. Two hundred and sixteen (20.7%) patients had advanced fibrosis. Ninety‐five (19.0%) patients who drank ≥1 cup of coffee had advanced fibrosis, compared with 121 (22.2%) patients who drank <1 cup (P=0.21). The amount of caffeine intake had positive correlation with the amount of alcohol intake (r_s=0.167, P<0.001). Although 231 (22.1%) patients reported alcohol consumption, only 11 (1%) had excessive alcohol intake. The prevalence of advanced fibrosis among patients with mild to moderate alcohol intake (26, 18.8%) was comparable to that among non‐drinkers (190, 21.0%) (P=0.57). Conclusion: Caffeine intake does not affect liver stiffness in chronic HBV‐infected patients. Patients who drink coffee regularly tend to drink alcohol. Most chronic HBV‐infected patients do not have excessive alcohol consumption. The prevalence of advanced fibrosis among mild to moderate alcohol drinkers was low in this population.     

Dietary iron intake and Type 2 diabetes incidence in postmenopausal women: the Iowa Women’s Health Study

Aims/hypothesis Recently, a clear biological link between iron metabolism and diabetes has emerged from epidemiological and experimental studies. We carried out a prospective study of dietary iron intake and incidence of Type 2 diabetes. Methods 35,698 postmenopausal women initially aged 55 to 69 years were followed for 11 years. Diet was assessed with a food frequency questionnaire at baseline.Results Intake of heme iron showed a positive association with incident Type 2 diabetes; the relative risks were 1.0, 1.07, 1.12, 1.14, and 1.28 across quintiles of heme iron (p trend =0.02) after adjustment for non-dietary and dietary risk factors. Heme iron showed a weak positive association among non-drinkers, but the association appeared to be stronger among subjects who consumed more alcohol. For example, in a model restricted to those who drank alcohol at least 15 g/day, adjusted relative risks across quintiles of heme iron were 1.0, 2.26, 3.22, 1.92, and 4.42 (p trend =0.05); and consumers of 30 g/day of more of supplemental iron had an adjusted relative risk equal to 3.03 (95% CI, 1.29–7.12)], compared to those who took no iron supplement. Non-heme iron was inversely associated with incidence of Type 2 diabetes. Amongst non-drinkers adjusted relative risks were 1.0, 0.83, 0.87, 0.72, and 0.67 across quintiles (p trend <0.01). This inverse association was lost among drinkers, in whom there was no association of diabetes incidence with non-heme iron.Conclusions/interpretation Greater dietary heme-iron intake and/or supplemental iron were associated with an increased risk of Type 2 diabetes, especially amongst those who drink alcohol.Abbreviations WHR waist-to-hip ratio - RR relative risk - Q1–Q5 quintiles 1–5     

Body mass index is a stronger predictor of alanine aminotransaminase levels than alcohol consumption

Background and Aims:  The relative effects of obesity compared to alcohol on liver injury are uncertain. We examined their effects on alanine aminotransferase (ALT) and gamma glutamyltransferase (GGT) levels in a population-based cohort.
Methods:  Adult residents (2610: 1326 males, 1284 females) from Busselton, Australia, participated in a cross-sectional survey determining alcohol intake as determined by a validated questionnaire, anthropometric measurements and serum analysis. Alcohol consumption was classified as never, light (<140 g/week), moderate (140–420 g/week) or heavy (>420 g/week).
Results:  The majority of subjects were either overweight (41%) or obese (17%). A minority of subjects were moderate (25%) or heavy drinkers (4%). Body mass index (BMI) and waist circumference were strongly associated with ALT and GGT ( P  < 0.0001 for all tests). Alcohol consumption was modestly associated with ALT in females ( P  = 0.01) but not in males ( P  = 0.9). In contrast, GGT was significantly associated with alcohol in both genders ( P  < 0.0005). The risk of an elevated ALT was seven-fold higher with obesity but only two-fold higher with moderate or heavy alcohol use. Obesity accounted for half of all elevated ALT levels in the cohort, whereas alcohol excess was responsible for less than 10%. No synergistic effect was observed between BMI or waist circumference and alcohol on ALT or GGT ( P  > 0.2 for all tests).
Conclusions:  Excess weight is more common than excessive alcohol consumption in the community and confers a greater risk of elevated aminotransaminase levels.     

Alterations in ethyl alcohol pharmacokinetics during oral consumption of malt liquor beverages in African Americans

Background: Malt liquor (ML) beverages have become increasingly popular among urban minority groups, due partly to their inexpensive price and targeted advertising. We hypothesized that nonfermented by‐products contained in ML beverages will alter the pharmacokinetics (PK) and pharmacodynamic (PD) effects of its ethanol content. In addition, we determined the effect of alcohol dehydrogenase (ADH) genotypes on the PK following consumption of ML beverages. Methods: The study was conducted in 31 healthy adult African‐American social drinkers, mean ± SD age of 22.3 ± 1.3 years, and weight of 70.7 ± 10.9 kg. Participants were administered ethanol, in randomized order, 2‐weeks apart, in the form of oral ML beverage (6%v/v), or isocaloric solution of diet soda–ethanol (DS–Etoh) beverage (6%v/v). During each session the beverage was consumed over 4 minutes and breath alcohol concentrations (BrAC) as well as subjective and behavioral effects of ethanol were evaluated over 180 minutes. Pharmacokinetic parameters of ethanol were calculated using Michaelis–Menten elimination kinetics. The effect of ML and ADH genotype on PK was evaluated using the Wilcoxon rank‐sum test and the Wilcoxon signed rank test, respectively. Results: Results show a slower mean rate of absorption, K_a, (0.12 vs. 0.15 min^?1, p = 0.03) and a longer time to reach maximum concentration, T_max, (28 vs. 23 minute, p < 0.01) for the ML compared with DS–Etoh beverage. The ML beverage resulted in a larger area under the BrAC–time curve compared with DS–Etoh beverage (8.4 vs. 6.8 min g/dl, p = 0.02). There was no difference in the subjective PD effects between the 2 beverages. Conclusion: Results show that exposure to ethanol following the consumption of ML beverages is different compared to that following nonmalt beverages in African‐Americans. These differences may be related to nonfermented by‐products present in commercially available ML products. These PK differences do not appear to result in significant perceived alcohol PD changes, nor are they related to ADH genotype.     

Dietary Total Isoflavone Intake Is Associated With Lower Systolic Blood Pressure: The Coronary Artery Risk Development in Young Adults (CARDIA) Study

The effect of dietary isoflavone intake on systolic blood pressure (SBP) has not been studied in a large community‐based cohort inclusive of African Americans. The authors analyzed data from the year 20 examination of the Coronary Artery Risk Development in Young Adults (CARDIA) study, including medical history, physical examination, and dietary intake surveys for 3142 participants. Multivariable linear regression models controlled for age, sex, body mass index, smoking, physical activity, and intakes of alcohol and total energy. Effect modification by race was tested. Overall, patients with hypertension had a lower daily intake of total dietary isoflavones (2.2±5.2 mg/d vs 4.1±11.7 mg/d; P<.001). In fully adjusted models, the highest quartile of dietary isoflavone intake was associated with a 4.4 mm Hg lower SBP on average compared with SBP for the lowest quartile. The relationship between dietary isoflavone intake and SBP was more pronounced among African Americans compared with Caucasians (P for interaction <.001). Greater dietary intake of isoflavones was independently associated with a lower SBP.     

Extrinsic factors modifying expressivity of the HFE variant C282Y, H63D, S65C phenotypes in 1,294 Danish men

This study analysed the influence of extrinsic factors on the phenotypic expression of HFE gene variants in ethnic Danish men. A cohort of 6,020 men aged 30-53 years was screened for HFE C282Y, H63D and S65C variants. Serum iron, serum transferrin, transferrin saturation, and serum ferritin were analysed in 1,452 men and 1,294 men completed a questionnaire on factors, which could influence iron balance. The C282Y allele was present in 5.6%, H63D in 12.8% and S65C in 1.8% of the men. In the entire series, 3% had elevated iron status markers (transferrin saturation ≥50%, ferritin ≥300 μg/L). Self-reported liver disease had an elevating effect and peptic ulcer a lowering effect on iron status markers. Age increased the fraction of men with elevated ferritin from 8.3% at 32-38 years to 16.2% at 46-53 years of age (p = 0.002). Blood donation had a lowering effect on iron status markers (p = 0.0001). Alcohol consumption elevated serum iron and serum ferritin (p = 0.001). Meat consumption had an elevating effect (p = 0.02) and milk consumption a lowering effect (p = 0.03) on serum ferritin. There was no influence of vitamin-mineral tablets on iron status markers. In adjusted logistic regression analysis, the HFE genotype had the highest impact on iron status markers; high alcohol consumption was significantly associated with elevated transferrin saturation. High age and high alcohol consumption were significantly associated with elevated ferritin and high egg consumption and blood donation was significantly associated with normal ferritin levels. In conclusion, the expressivity of HFE variant phenotypes in Danish men was enhanced by alcohol and meat consumption and decreased by milk and egg consumption and blood donation.     

Alcohol Consumption and the Risk of Hypertension in Men and Women: A Systematic Review and Meta‐Analysis

J Clin Hypertens (Greenwich). 2012;14:792–798. ©2012 Wiley Periodicals, Inc. Heavy alcohol intake increases the risk of hypertension, but the relationship between light to moderate alcohol consumption and incident hypertension remains controversial. The authors sought to analyze the dose‐response relationship between average daily alcohol consumption and the risk of hypertension via systematic review and meta‐analysis. Electronic databases were searched for prospective control studies examining quantitative measurement of alcohol consumption and biological measurement of outcome. The primary endpoint was the risk of developing hypertension based on alcohol consumption. The level of alcohol consumption from each study was assigned to categorical groups based on the midpoint of their alcohol consumption classes to make possible the comparison of heterogeneous classification of alcohol intake. A total of 16 prospective studies (33,904 men and 193,752 women) were included in the analysis. Compared with nondrinkers, men with alcohol consumption with <10 g/d and 11 to 20 g/d had a trend toward increased risk of hypertension (relative risk [RR], 1.03; 95% confidence interval [CI], 0.94–1.13; P=.51) and (RR, 1.15; 95% CI, 0.99–1.33; P=.06), respectively, whereas a significantly increased risk of hypertension was found with heavy alcohol consumption of 31 to 40 g/d (RR, 1.77; 95% CI, 1.39–2.26; P<.001) and >50 g/d (RR, 1.61; 95% CI, 1.38–1.87; P<.001). Among women, the meta‐analysis indicated protective effects at <10 g/d (RR, 0.87; 95% CI, 0.82–0.92; P<.001) and a trend toward decreased risk of hypertension with alcohol consumption 11 to 20 g/d (RR, 0.9; 95% CI, 0.87–1.04; P=.17), whereas a significantly increased risk of hypertension was indicated with heavy alcohol consumption of 21 to 30 g/d (RR, 1.16; 95% CI, 0.91–1.46; P=.23) and 31 to 40 g/d (RR, 1.19; 95% CI, 1.07–1.32; P=.002). In men, heavy alcohol consumption is associated with increased risk of hypertension, whereas there is a trend toward increased risk of hypertension with low and moderate alcohol consumption. The relationship between alcohol consumption and hypertension is J‐shaped in women. Limiting alcohol intake should be advised for both men and women.     

HFE,SLC40A1, HAMP,HJV, TFR2, and FTL mutations detected by denaturing high‐performance liquid chromatography after iron phenotyping and HFE C282Y and H63D genotyping in 785 HEIRS Study participants

We sought to identify mutations that could explain iron phenotype heterogeneity in adults with previous HFE genotyping to detect C282Y and H63D. HEIRS Study participants genotyped for C282Y and H63D were designated as high transferrin saturation (TS) and/or serum ferritin (SF) (high TS/SF), low TS/SF, or controls. We grouped 191 C282Y homozygotes as high TS/SF, low TS/SF, or controls, and 594 other participants by race/ethnicity as high TS/SF or controls. Using denaturing high‐performance liquid chromatography (DHPLC), we screened 20 regions of HFE, SLC40A1, HAMP, HJV, TFR2, and FTL in each participant. DHPLC analyses were successful in 99.3% of 791 participants and detected 117 different mutations. In C282Y homozygotes, 4.0% of high TS/SF participants had SLC40A1 Q248H, HAMP ‐72C>T, or HAMP R59G heterozygosity (0% Controls; P = 0.1200). In whites, 4.1% with high TS/SF and 1.3% of controls had HFE S65C or E168Q (P = 0.3049). HJV c.‐6C>G and FTL L55L frequencies were greater in whites with high TS/SF than controls (0.0811 vs. 0.0200, P = 0.0144; 0.5743 vs. 0.4400, P = 0.0204, respectively). One Hispanic with high TS/SF (1.3%) had HAMP G71D heterozygosity. In blacks, SLC40A1 Q248H frequencies did not differ significantly between high TS/SF and control participants. Among Asians, 2.8% with high TS/SF were HFE V295A heterozygotes. Mutations other than HFE C282Y and H63D reported to be pathogenic were infrequently detected in high TS/SF participants. Genetic regions in linkage disequilibrium with HJV c.‐6C>G and FTL L55L could partly explain high TS/SF phenotypes in whites. Am. J. Hematol., 2009. Published 2009 Wiley‐Liss, Inc.     

The dynamics of hepcidin‐ferroportin internalization and consequences of a novel ferroportin disease mutation

The hepcidin‐ferroportin axis underlies the pathophysiology of many iron‐associated disorders and is a key target for the development of therapeutics for treating iron‐associated disorders. The aims of this study were to investigate the dynamics of hepcidin‐mediated ferroportin internalization and the consequences of a novel disease‐causing mutation on ferroportin function. Specific reagents for ferroportin are limited; we developed and characterized antibodies against the largest extracellular loop of ferroportin and developed a novel cell‐based assay for studying hepcidin‐ferroportin function. We show that hepcidin‐mediated ferroportin internalization is a rapid process and could be induced using low concentrations of hepcidin. Targeted next‐generation sequencing utilizing an iron metabolism gene panel developed in our group identified a novel ferroportin p.D84E variant in a patient with iron overload. Wild‐type and mutant ferroportin constructs were generated, transfected into HEK293 cells and analysed using an all‐in‐one flow‐cytometry‐based assay to study the effects on hepcidin‐mediated internalization and iron transport. Consistent with the classical phenotype of ferroportin disease, the p.D84E mutation results in an inability to transport iron and hepcidin insensitivity. These results validate a recently proposed 3D‐structural model of ferroportin and highlight the significance of this variant in the structure and function of ferroportin. Our novel ferroportin antibody and assay will be valuable tools for investigating the regulation of hepcidin/ferroportin function and the development of novel approaches for the therapeutic modulation of iron homeostasis.     

Results of a dietary survey in the Calvados. Dietary intake, tobacco and alcohol consumption

A survey on individual nutritional intake was conducted in a representative sample of 1,975 people in the French province of Calvados using a dietary history method. The energy ration (2,964 kcal/d in males, 2,148 kcal/d in females) was found to exceed the recommended allowances by 150 kcal/d in women and by 300 kcal/d in men, corresponding to alcohol consumption. The trends observed were similar to those seen elsewhere in France and other developed countries: a diet with a high proportion (41-43 p. 100) of lipids and saturated fatty acids (16-18 p. 100) mainly due to reduced consumption of vegetable foods; a high intake of cholesterol (513-422 mg) and a low ration of polyunsaturated fatty acids (3.9-4.5 p. 100) leading to a high risk of vascular diseases, particularly of the coronary arteries. The high intake of alcohol may be responsible for the high incidence of alcohol-related diseases, possibly in association with tobacco. The intake of vitamins and minerals was adequate, with the exception of iron, which was below the recommended allowance for females. In contrast with common belief, the dietary energy intake increased when alcohol consumption increased in both sexes. For tobacco, the energy ration decreased moderately in females only with increasing consumption; no relationship was observed in males.     

The subjective, rather than the disinhibiting, effects of alcohol are related to binge drinking

Background: Evidence suggests that alcohol‐related problems are associated with impulsivity and disinhibited behavior. Less certain is whether disinhibited behavior is due to an impulsive disposition or alcohol’s ability to disinhibit some people more than others. There are a range of disinhibited behaviors associated with alcohol, including excessive alcohol consumption, bingeing. The study tested whether nondependent alcohol bingers showed more disinhibition after placebo and/or alcohol relative to nonbingers and whether this was related to enhanced motivation to drink following a priming dose of alcohol. Methods: Twenty participants (10 bingers) attended the laboratory twice. Baseline measures included impulsivity, alcohol‐related cognitions, alcohol urge, and mood. Participants were preloaded with alcohol (male: 0.6 g/kg, female: 0.5 g/kg) and placebo (counterbalanced). After a 20‐minute rest, participants completed 2 impulsivity tasks (Two Choice & Time Estimation) separated by second urge and mood ratings. Results: Bingers did not show greater impulsivity characteristics but were more concerned about their drinking (p = 0.02) and ability to control drinking (p = 0.04). A priming effect was found: alcohol urge increased after alcohol but not placebo (p = 0.006). Bingers reported greater tolerance to the sedative (p = 0.05) and lightheaded (p = 0.04) effects of alcohol, relative to nonbingers. Binge status was not associated with impulsivity task performance, while preload type (alcohol/placebo) supported only marginal associations. Conclusions: Risk of binge drinking in nondependent individuals is not strongly affected by impulsive personality characteristics or alcohol’s ability to induce behavioral disinhibition. However, alcohol did lead to a priming effect and bingers were more tolerant to the sedative and lightheaded effects of alcohol relative to placebo. Risk of binge drinking is associated with the subjective effects of a priming dose of alcohol.