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Some patients with hemochromatosis (HC) experience fatigue, heart failure or arrhythmias, diabetes mellitus, liver damage, impotence, or arthritis. We examined self-reported symptoms and clinical conditions in persons homozygous for HFE C282Y, the major HC-associated gene mutation, identified in the Hemochromatosis and Iron Overload Screening (HEIRS) Study, a multi-center, multi-ethnic study in which 101,168 adults were recruited from primary care settings. Non-Hispanic Caucasian C282Y homozygotes were compared to participants without HFE C282Y or H63D alleles (controls) with transferrin saturation (TfS) and serum ferritin (SF) levels in the middle half of gender-specific distributions. Evaluation included a medical history, focused physical examination, and repeat SF. Among 44,082 non-Hispanic Caucasian participants screened at five Field Centers in the United States and Canada, 282 persons homozygous for C282Y were identified, comprising three groups: newly-diagnosed cases with normal (N=64) or elevated (N=131) SF (>200 μg/L in women, >300 μg/L in men), and previously-diagnosed cases (N=87). There were 364 non-Hispanic Caucasian controls. Significant differences were observed for six of 38 outcomes. Previously diagnosed C282Y homozygotes and newly diagnosed homozygotes with elevated SF reported significantly more chronic fatigue than controls (p=0.002). All groups of C282Y homozygotes reported weight loss more often than controls (p<0.001). Excessive thirst was reported more often than controls by newly diagnosed C282Y homozygotes, regardless of SF level (p=0.004), but there was no difference in self-reported history of diabetes. Joint stiffness was more common among newly diagnosed C282Y homozygotes with elevated SF than among control subjects (p<0.001). Swelling or tenderness of the second and third metacarpophalangeal joints and increased pigmentation were also more common among previously diagnosed C282Y homozygotes and newly diagnosed homozygotes with elevated SF than among controls (p=0.001 and p=0.002, respectively). The prevalences of manifestations related to liver or heart disease among C282Y homozygotes were not significantly different from controls. There were no differences among the three groups of C282Y homozygotes in the prevalences of any symptoms or clinical conditions. In summary, some symptoms and conditions associated with HC were more prevalent among C282Y homozygotes than among controls. However, C282Y homozygotes identified by screening in primary care settings did not have a higher prevalence of most symptoms and signs associated with HC than control subjects.

Some patients with hemochromatosis (HC) experience fatigue, heart failure or arrhythmias, diabetes mellitus, liver damage, impotence, or arthritis. We examined self-reported symptoms and clinical conditions in persons homozygous for HFEC282Y, the major HC-associated gene mutation, identified in the Hemochromatosis and Iron Overload Screening (HEIRS) Study, a multi-center, multi-ethnic study in which 101,168 adults were recruited from primary care settings. Non-Hispanic Caucasian C282Y homozygotes were compared to participants without HFEC282Y or H63D alleles (controls) with transferrin saturation (TfS) and serum ferritin (SF) levels in the middle half of gender-specific distributions. Evaluation included a medical history, focused physical examination, and repeat SF. Among 44,082 non-Hispanic Caucasian participants screened at five Field Centers in the United States and Canada, 282 persons homozygous for C282Y were identified, comprising three groups: newly-diagnosed cases with normal (N=64) or elevated (N=131) SF (>200 μg/L in women, >300 μg/L in men), and previously-diagnosed cases (N=87). There were 364 non-Hispanic Caucasian controls. Significant differences were observed for six of 38 outcomes. Previously diagnosed C282Y homozygotes and newly diagnosed homozygotes with elevated SF reported significantly more chronic fatigue than controls (p=0.002). All groups of C282Y homozygotes reported weight loss more often than controls (p<0.001). Excessive thirst was reported more often than controls by newly diagnosed C282Y homozygotes, regardless of SF level (p=0.004), but there was no difference in self-reported history of diabetes. Joint stiffness was more common among newly diagnosed C282Y homozygotes with elevated SF than among control subjects (p<0.001). Swelling or tenderness of the second and third metacarpophalangeal joints and increased pigmentation were also more common among previously diagnosed C282Y homozygotes and newly diagnosed homozygotes with elevated SF than among controls (p=0.001 and p=0.002, respectively). The prevalences of manifestations related to liver or heart disease among C282Y homozygotes were not significantly different from controls. There were no differences among the three groups of C282Y homozygotes in the prevalences of any symptoms or clinical conditions. In summary, some symptoms and conditions associated with HC were more prevalent among C282Y homozygotes than among controls. However, C282Y homozygotes identified by screening in primary care settings did not have a higher prevalence of most symptoms and signs associated with HC than control subjects.

Mean serum ferritin concentration (SF) has been positively associated with diabetes mellitus in some racial/ethnic groups. We evaluated the associations of self-reported diabetes mellitus with SF, serum transferrin saturation (TfSat), and HFE C282Y and H63D mutations in six racial/ethnic groups recruited at five Field Centers in the multi-center, primary care-based HEIRS Study. Analyses were conducted on the 97,470 participants for whom pertinent data were available. Participants who reported that they had been previously diagnosed with diabetes mellitus and/or hemochromatosis or iron overload were compared to participants who did not report a previous diagnosis. The overall prevalence of diabetes mellitus was 13.8%; the highest prevalence was observed in Native Hawaiian/Pacific Islanders (20.1%). 2.0% of all participants with diabetes mellitus and 2.2% of whites with diabetes mellitus reported that they also had hemochromatosis or iron overload. Mean SF was elevated in women with diabetes mellitus in all racial/ethnic groups and in American Indian/Alaska Native men with diabetes mellitus. Mean SF was significantly lower in Asian men with diabetes mellitus. Mean TfSat was lower (or not increased) in participants with diabetes mellitus than in those without diabetes mellitus. There was no significant association of diabetes mellitus with HFE genotype. Mean SF was greater (p <0.0001) in women with diabetes mellitus than in those without diabetes mellitus for HFE genotypes except C282Y/C282Y and C282Y/H63D. There was a significant positive association of log SF and diabetes mellitus in a logistic regression analysis after adjusting for age, gender, racial/ethnic group, HFE genotype, and Field Center. We conclude that SF is significantly associated with diabetes mellitus, even at levels of SF below those typically associated with hemochromatosis or iron overload.

Mean serum ferritin concentration (SF) has been positively associated with diabetes mellitus in some racial/ethnic groups. We evaluated the associations of self-reported diabetes mellitus with SF, serum transferrin saturation (TfSat), and HFEC282Y and H63D mutations in six racial/ethnic groups recruited at five Field Centers in the multi-center, primary care-based HEIRS Study. Analyses were conducted on the 97,470 participants for whom pertinent data were available. Participants who reported that they had been previously diagnosed with diabetes mellitus and/or hemochromatosis or iron overload were compared to participants who did not report a previous diagnosis. The overall prevalence of diabetes mellitus was 13.8%; the highest prevalence was observed in Native Hawaiian/Pacific Islanders (20.1%). 2.0% of all participants with diabetes mellitus and 2.2% of whites with diabetes mellitus reported that they also had hemochromatosis or iron overload. Mean SF was elevated in women with diabetes mellitus in all racial/ethnic groups and in American Indian/Alaska Native men with diabetes mellitus. Mean SF was significantly lower in Asian men with diabetes mellitus. Mean TfSat was lower (or not increased) in participants with diabetes mellitus than in those without diabetes mellitus. There was no significant association of diabetes mellitus with HFEgenotype. Mean SF was greater (p <0.0001) in women with diabetes mellitus than in those without diabetes mellitus for HFEgenotypes except C282Y/C282Y and C282Y/H63D. There was a significant positive association of log SF and diabetes mellitus in a logistic regression analysis after adjusting for age, gender, racial/ethnic group, HFEgenotype, and Field Center. We conclude that SF is significantly associated with diabetes mellitus, even at levels of SF below those typically associated with hemochromatosis or iron overload.

We compared initial screening data of 44,149 whites (17,043 men; 27,106 women) and 26,947 blacks (9,788 men; 17,159 women) who reported no previous diagnosis of hemochromatosis or iron overload from a primary care-based sample of ~100,000 adults ≥25 years recruited from 5 Field Centers. Each underwent transferrin saturation (TfSat) and serum ferritin (SF) measurements without regard to fasting, and HFEC282Y and H63D genotyping. We observed these mean TfSat and SF values and percentages of participants with elevated biochemical measurements (TfSat >50% and SF >300 ng/mL, men; TfSat >45% and SF >200 ng/mL, women):

Designing an optimal screening approach for hemochromatosis and iron overload requires knowledge of racial/ethnic subpopulations and frequencies of HFEmutations and phenotypes in geographic areas. In the HEIRS Study, HFEC282Y and H63D genotypes and prevalences of participants who met biochemical criteria for further evaluation (transferrin saturation >50% and ferritin >300 ng/mL, men; >45% and >200 ng/mL, women) were compared in a primary care-based sample of ~100,000 adults ≥25 years from 5 Field Centers. There were different respective HFEC282Y and H63D genotype frequencies in Whites, Blacks, Asians, and Hispanics across geographic areas (all p<0.0001), but not in Native Americans or Pacific Islanders. In Whites, the C282Y/C282Y proportion was significantly higher in AL than in CA or OR/HI. AL also had a significantly higher proportion of C282Y/wt than CA or OR/HI. In Blacks, D.C. had a significantly higher proportion of C282Y and H63D genotypes than AL. ONT had a significantly higher H63D genotype proportion than AL. In Asians, CA had a significantly higher proportion of H63D genotypes than OR/HI or ONT. In Hispanics, there were significant differences between: AL and CA; AL and D.C.; CA and D.C.; CA and OR/HI; D.C. and OR/HI; and D.C. and ONT. We also observed:

Designing an optimal screening approach for hemochromatosis and iron overload requires knowledge of racial/ethnic subpopulations and frequencies of HFE mutations and phenotypes in geographic areas. In the HEIRS Study, HFE C282Y and H63D genotypes and prevalences of participants who met biochemical criteria for further evaluation (transferrin saturation >50% and ferritin >300 ng/mL, men; >45% and >200 ng/mL, women) were compared in a primary care-based sample of ~100,000 adults ≥25 years from 5 Field Centers. There were different respective HFE C282Y and H63D genotype frequencies in Whites, Blacks, Asians, and Hispanics across geographic areas (all p<0.0001), but not in Native Americans or Pacific Islanders. In Whites, the C282Y/C282Y proportion was significantly higher in AL than in CA or OR/HI. AL also had a significantly higher proportion of C282Y/wt than CA or OR/HI. In Blacks, D.C. had a significantly higher proportion of C282Y and H63D genotypes than AL. ONT had a significantly higher H63D genotype proportion than AL. In Asians, CA had a significantly higher proportion of H63D genotypes than OR/HI or ONT. In Hispanics, there were significant differences between: AL and CA; AL and D.C.; CA and D.C.; CA and OR/HI; D.C. and OR/HI; and D.C. and ONT. We also observed: Prevalences of Participants Who Met Biochemical Criteria for Further Evaluation Race/Ethnicity Geographic Area Prevalence (%) 95% CI Asians California 5.54 4.98, 6.16 Oregon/Hawaii 5.06 4.29, 5.95 Ontario 4.25 3.69, 4.88 Alabama 1.41 0.25, 7.56 D.C. 0.96 0.26, 3.42 Pacific Islanders California 3.66 1.25, 10.21 Oregon/Hawaii 3.47 2.23, 5.36 Native Americans Alabama 2.65 0.91, 7.52 Oregon/Hawaii 2.50 0.69, 8.66 D.C. 0.99 0.17, 5.40 Ontario 0.75 0.21, 2.71 Whites Ontario 2.31 2.08, 2.56 California 1.93 1.56, 2.37 Oregon/Hawaii 1.52 1.34, 1.73 Alabama 1.48 1.26, 1.74 D.C. 1.40 0.80, 2.43 Hispanics Ontario 1.92 0.82, 4.41 California 1.52 1.28, 1.79 Oregon/Hawaii 1.34 0.73, 2.4 Alabama 0.84 0.23, 3.01 D.C. 0.74 0.48, 1.16 Blacks D.C. 1.75 1.56, 1.96 Ontario 1.55 0.52, 4.45 Alabama 1.09 0.90, 1.32 Oregon/Hawaii 0.92 0.31, 2.66 California 0.86 0.29, 2.51 The percentage of men who met biochemical criteria for further evaluation was greater than that of women. We conclude that 1) C282Y and H63D genotype frequencies vary significantly within a single racial/ethnic group across geographic regions; and 2) the percentage of participants who met biochemical criteria for further evaluation varies by racial/ethnic group.

We compared initial screening data of 44,149 whites (17,043 men; 27,106 women) and 26,947 blacks (9,788 men; 17,159 women) who reported no previous diagnosis of hemochromatosis or iron overload from a primary care-based sample of ~100,000 adults ≥25 years recruited from 5 Field Centers. Each underwent transferrin saturation (TfSat) and serum ferritin (SF) measurements without regard to fasting, and HFE C282Y and H63D genotyping. We observed these mean TfSat and SF values and percentages of participants with elevated biochemical measurements (TfSat >50% and SF >300 ng/mL, men; TfSat >45% and SF >200 ng/mL, women): Participants Mean % TfSat (95% CI) Elevated TfSat, % Participants Mean SF, ng/mL (95% CI) Elevated SF, % Participants White men 32.4 (32.3, 32.6) 7.05 150.9 (149.1, 152.8) 19.49 Black men 29.3 (29.1, 29.5) 4.03 178.4 (175.5, 181.3) 25.95 p Value <0.0001 <0.0001 <0.0001 <0.0001 White women 27.5 (27.3, 27.6) 6.62 63.0 (62.3, 63.7) 8.74 Black women 23.3 (23.1, 23.4) 3.04 68.3 (67.2, 69.4) 15.43 p Value <0.0001 <0.0001 <0.0001 <0.0001 In participants grouped by decade, mean TfSat was greater in white men than in black men, and in white women than in black women (all p<0.0001). Mean SF was greater in black men than in white men in all decades except 25–34 years, and in black women than in white women in decades ≥45 years. SF increased with age to ~45 years in white men and ~50 years in black men, and then decreased. In white women, SF rose with age until ~62 years and less rapidly to age ≥80. In black women, SF rose with age until ~62 years and then decreased. C282Y allele frequency was 0.0700 (95% CI: 0.0683, 0.0717) in whites and 0.0119 (0.0110, 0.0129) in blacks. H63D allele frequency was 0.1532 (0.1509, 0.1556) in whites and 0.0299 (0.0284, 0.0313) in blacks. Frequencies of genotypes with C282Y or H63D were greater in whites than in blacks (all p<0.0001). The prevalence of elevated TfSat and SF plus genotype C282Y/C282Y was 0.003 in whites and 0.00004 in blacks (p<0.0001). The prevalence of elevated TfSat and SF plus genotype C282Y/C282Y, C282Y/H63D, or H63D/H63D was 0.006 in whites and 0.0003 in blacks (p<0.0001). We conclude that: 1) the prevalence of elevated TfSat is higher in whites and the prevalence of elevated SF is higher in blacks; 2) SF levels increase with age; 3) HFE C282Y and H63D alleles occur more frequently in whites than in blacks; and 4) the prevalence of elevated TfSat and SF plus genotypes with two common HFE mutations is greater in whites than in blacks.