Skip main navigation

Heme Oxygenase-1 Gene Promoter Microsatellite Polymorphism Is Associated With Progressive Atherosclerosis and Incident Cardiovascular Disease

Originally published, Thrombosis, and Vascular Biology. 2015;35:229–236



The enzyme heme oxygenase-1 (HO-1) exerts cytoprotective effects in response to various cellular stressors. A variable number tandem repeat polymorphism in the HO-1 gene promoter region has previously been linked to cardiovascular disease. We examined this association prospectively in the general population.

Approach and Results—

Incidence of stroke, myocardial infarction, or vascular death was registered between 1995 and 2010 in 812 participants of the Bruneck Study aged 45 to 84 years (49.4% males). Carotid atherosclerosis progression was quantified by high-resolution ultrasound. HO-1 variable number tandem repeat length was determined by polymerase chain reaction. Subjects with ≥32 tandem repeats on both HO-1 alleles compared with the rest of the population (recessive trait) featured substantially increased cardiovascular disease risk (hazard ratio [95% confidence interval], 5.45 [2.39, 12.42]; P<0.0001), enhanced atherosclerosis progression (median difference in atherosclerosis score [interquartile range], 2.1 [0.8, 5.6] versus 0.0 [0.0, 2.2] mm; P=0.0012), and a trend toward higher levels of oxidized phospholipids on apolipoprotein B-100 (median oxidized phospholipids/apolipoprotein B level [interquartile range], 11364 [4160, 18330] versus 4844 [3174, 12284] relative light units; P=0.0554). Increased cardiovascular disease risk in those homozygous for ≥32 repeats was also detected in a pooled analysis of 7848 participants of the Bruneck, SAPHIR, and KORA prospective studies (hazard ratio [95% confidence interval], 3.26 [1.50, 7.33]; P=0.0043).


This study found a strong association between the HO-1 variable number tandem repeat polymorphism and cardiovascular disease risk confined to subjects with a high number of repeats on both HO-1 alleles and provides evidence for accelerated atherogenesis and decreased antioxidant defense in this vascular high-risk group.


Low-grade inflammation, oxidation, and vascular remodeling are cardinal components in the pathophysiology of atherosclerosis.1 Heme oxygenase-1 (HO-1) is the inducible, rate-limiting enzyme of heme degradation and exerts potent anti-inflammatory, antioxidative, and antiapoptotic effects in response to various stressors.2,3 Compelling evidence for a protective effect of HO-1 on the vasculature derives from animal studies, demonstrating that HO-1 suppresses the development of atherosclerotic lesions46 and thrombi.7 Moreover, prominent endothelial damage was observed in rare human HO-1 deficiency,8 as well as in HO-1 knockout mice.9

There is a (GT)n dinucleotide repeat polymorphism (variable number tandem repeat, VNTR) in the HO-1 gene promoter region, and higher repeat numbers translate into lower enzyme expression.1013 A deficiency in HO-1–mediated vascular protection in subjects with greater repeat lengths was proposed to predispose to atherosclerosis and its clinical sequelae myocardial infarction (MI) and stroke.14 Studies examining the association between (GT)n repeat length and cardiovascular disease (CVD) have to date been restricted to selected patient series, mainly subjects admitted for coronary angiography or patients with coronary artery disease (CAD) or peripheral arterial disease, and yielded inconsistent results. A summary of the literature is presented in Table 1. Apart from differences in study design, patient characteristics, and end point definitions, heterogeneous results may arise from the different cut-offs applied to categorize repeat number.

Table 1. Summary of the Literature on HO-1 VNTR Polymorphism and Cardiovascular Disease End Points in Humans

ReferencePrimary End Pointn (Cases)Years of FUSample CompositionVNTR Cut-Off(s) (≥)Result*Effect (Short Allele)Effect (Long Allele)
Exner 200115Restenosis after femoropopliteal BA96 (23)0.5Caucasian, PAD25 and 29p(D) OR 0.2 (0.06, 0.70)
Chen 200211CAD796 (474)CCAsian, CAG23 and 32p(D) OR 4.7 (1.9, 12.0) in diabetics
Kaneda 200216CAD577 (298)CSAsian, CAG27p(E) S/S vs L/L: OR 0.23 (0.07, 0.72) in subjects with high cholesterol; OR 0.23 (0.08, 0.71) in diabetics; OR 0.40 (0.17, 0.95) in smokers
Schillinger 200217AAA, CAD, PAD271 (210)CCCaucasian, vascular risk patients25p(R) more L/L genotype in AAA, P=0.04 NS for CAD, PAD
Chen 200318Restenosis after coronary stenting, ACE323 (111)0.5Asian, CAD26p(D) OR 3.74 (1.61, 8.70) for stenting (D) OR 3.26 (1.58, 6.72) for ACE
Endler 200419CAD, MI649 (438)CCCaucasian, vascular risk patients25n(D) P=0.94
Funk 200420Ischemic stroke or TIA797 (399)CCCaucasian, stroke25p(E) S/S vs L/L: OR 0.2 (0.1,0.6)
Schillinger 200421Restenosis after femoropopliteal BA381 (95)0.5Caucasian, PAD25p(R) RR 2.33 (1.41, 4.17), NS for stenting
Dick 200522MI or PCI or CABG472 (133)1.75 (M)Caucasian, PAD25p(R) HR 2.17 (1.15, 4.17), NS for MACE, all-cause mortality, cerebrovascular events
Gulesserian 200523Restenosis after coronary stenting199 (102)0.5–0.75Caucasian, CAD30p(D) OR 1.9 (1.0, 3.4), stronger effect in smokers
Li 200524Restenosis after coronary stenting187 (52)0.5Asian, CAD30 and 38n(D) 30.8% restenosis in S carriers, 22.4% in others; P=0.22
Wijpkema 200625Restenosis after coronary angioplasty3146 (287)0.8 (M)Caucasian, CAD25nS/L vs. S/S: HR 1.14 (0.90, 1.45); L/L vs. S/S: HR 0.87 (0.55, 1.38)
Tiroch 200726Restenosis after coronary stenting1357 (401)0.5Caucasian, CAD25nrestenosis in 29.2% (S/S), 29.5% (S/L), 29.6% (L/L); P=0.99
Chen 200827CAD986 (664)CSAsian, CAG27p(R) OR 2.81 (1.22, 6.47) in diabetics; NS with adjustment for ferritin and bilirubin
Lüblinghoff 200928CAD3219 (2526)§7.8 (M)Caucasian, CAG26 or 28nS/L vs. S/S: OR 0.70 (0.49, 1.01); L/L vs. S/S: OR 0.71 (0.49, 1.02)
Bai 201029Ischemic stroke347 (183)CCAsian, stroke patients and hospital controls27p(M) OR 2.07 (1.07–4.01) in subjects with low HDL
Wu 201030CVD mortality504 (22)10.7 (M)Asian, arsenic exposure27p(R) OR 2.63 (1.11, 6.25)
Chen 201213CAD4596 (2298)CCAsian, general population26p(E) S/S vs L/L: OR 0.60 (0.44, 0.81) in subjects with high oxidative stress
Chen 201331CVD1080 (307)4.2 (M)Asian, hemodialysis27p(R) HR 1.62 (1.28, 2.04)
Gregorek 201332AAA234 (117)CCCaucasian, AAA patients and hospital controls25nS/L vs. L/L: OR 1.53 (0.90, 3.09); S/S vs. L/L: OR 1.24 (0.87, 1.96)

AAA indicates abdominal aortic aneurysm; ACE, adverse coronary events; BA, balloon angioplasty; CABG, coronary artery bypass grafting; CAD, coronary artery disease; CAG, coronary angiography; CC, case-control study; CS, cross-sectional study; CVD, cardiovascular disease; FU, follow-up; HDL, high-density lipoprotein cholesterol; HO-1, heme oxygenase-1; HR, hazard ratio; (M), median follow-up in years; MACE, major adverse cardiovascular events; MI, myocardial infarction; NS, not statistically significant; OR, odds ratio; PAD, peripheral arterial disease; PCI, percutaneous coronary intervention; RR, risk ratio; TIA, transient ischemic attack; and VNTR, variable number tandem repeat.

*p, positive study—found significant association of HO-1 VNTR length with primary end point; n, negative study—did not find significant association of HO-1 VNTR length with primary end point.

(D), dominant effect, ie, applies to allele carriers (eg, pooled S/S and S/L vs L/L); (E), extreme group comparison (eg, S/S vs L/L); (R), recessive effect, ie, applies to those homozygous for the respective allele (eg, S/S vs pooled S/L and L/L); (M), 1 study applied the cut-off to average within-subject allele length, forming L and S genotypes.

258 MCI and 180 stable CAD.

§2526 CAD and 1339 MI; 752 death.

We present here the first prospective study on the potential relationship of the HO-1 (GT)n polymorphism with CVD conducted in the general community.

Materials and Methods

Materials and Methods are available in the online-only Data Supplement.


HO-1 genotyping resulted in unambiguous results for 812 of 816 subjects for which DNA samples were available (call rate, 99.5%). Duplicate measurement of 95 random DNA samples yielded 100% concordant findings. The distribution of (GT)n repeat lengths ranged from 12 to 44 repeats and was trimodal, with peaks at 23, 30, and 37 repeats, constituting 20.5%, 40.9%, and 3.9% of alleles (Figure 1). The most common allele combinations were 30/30 and 23/30, observed in n=145 (17.9%) individuals each.

Figure 1.

Figure 1. Joint distribution of heme oxygenase-1 (HO-1) variable number tandem repeat (VNTR) length on each allele. Numbers give the count of subjects that had the corresponding combination of allele lengths. Black lines show the cut-offs we applied to form genotype groups.

Categorization of study subjects by VNTR length (S, <23; M, 23–31; L, ≥32) resulted in only 2 subjects homozygous for short alleles (SS genotype), and we therefore merged SS and SM genotype groups to form SS/SM (n=35), MM (n=665), ML (n=101), and LL (n=11) groups. Distributions of baseline characteristics according to these 4 groups are shown in Table 2. Levels of standard risk factors emerged as independent of HO-1 genotype.

Table 2. Baseline Characteristics of the Study Population According to Heme Oxygenase-1 Genotype

SS/SMMMMLLLPany differencePtrendPLL vs other
n (%)35 (4.3)665 (81.9)101 (12.4)11 (1.4)
VNTR range (shorter allele)12–2223–3123–3132–37
VNTR range (longer allele)12–3123–3132–4436–38
Baseline characteristics
 Age, y59.8±11.062.9±11.162.6±11.165.3±9.80.3680.3610.451
 Male sex, n (%)18 (51.4)337 (50.7)41 (40.6)5 (45.5)0.2930.1160.813
 Body mass index, kg/m225.2 (23.4, 27.7)25.3 (23.1, 27.8)25.7 (23.3, 27.8)24.5 (22.8, 26.1)0.6940.9960.350
 Current smoking, n (%)8 (22.9)131 (20.2)16 (16.0)1 (9.1)0.7430.3460.458
 Diabetes mellitus, n (%)2 (5.7)74 (11.1)10 (9.9)1 (9.1)0.8500.9700.748
 Systolic BP, mm Hg147.9±21.3147.9±20.7150.9±21.3147.1±15.40.6500.6760.650
 Diastolic BP, mm Hg87.2±10.186.9±9.188.2±9.787.0±5.30.7330.5080.927
 Total cholesterol, mg/dL221.7±39.6229.6±42.9235.5±42.4231.6±33.40.5120.1870.948
 HDL cholesterol, mg/dL59.9±17.558.8±16.158.1±16.456.4±15.40.7340.2670.567
 Ferritin, ng/mL65 (32, 169)88 (36, 170)64 (28, 126)46 (25, 161)0.204*0.194*0.399*
 hs-CRP, mg/L1.9 (0.9, 3.4)1.6 (0.8, 3.2)2.0 (1.1, 3.4)1.8 (1.4, 2.3)0.098*0.429*0.679*

Values are given as n (%), mean±SD, or median (interquartile range); Ptrend is for linear trend; P values are adjusted for age and sex, except those for age and sex, which are only adjusted for the other; S, <23 tandem repeats; M, 23–31 tandem repeats; L, ≥32 tandem repeats.

BP indicates blood pressure; HDL, high-density lipoprotein; hs-CRP, high-sensitivity C-reactive protein; and VNTR, variable number tandem repeat.

*Variables were log-transformed for significance testing.

Crude incidence rates (95% confidence intervals [CIs]) for CVD were 6.5 (0.0, 15.3), 13.2 (10.8, 15.8), 13.0 (7.1, 19.8), and 65.1 (24.1, 130.4) events per 1000 person-years for SS/SM, MM, ML, and LL groups, respectively. Accordingly, 55% of subjects in the LL group developed hard CVD end points (stroke, MI, or vascular death) in the 15-year follow-up period. End point–specific event counts during the survey period in LL subjects and in other subjects were 4 and 61 for stroke, 2 and 51 for MI, and 0 and 20 for vascular death not caused by stroke or MI.

Under adjustment for age and sex, subjects homozygous for the longest repeat lengths (LL) faced a substantially elevated risk for CVD compared with MM subjects (hazard ratio (HR) [95% CI], 5.46 [2.39, 12.50]; P<0.0001; Table 3). A recessive model best fitted the data and revealed a HR [95% CI] of 5.45 [2.39, 12.42] (P<0.0001) in a comparison of LL to the rest of the study population. Effects remained virtually unchanged under further multivariable adjustment, were similar when excluding 50 subjects with prior CVD (HR [95% CI], 4.44 [1.63, 12.10]; P=0.0036), and were highly significant for the extended CVD end point as well (P<0.0001). Analyses of individual disease end points yielded a HR [95% CI] of 7.87 [2.84, 21.86] (P<0.0001) for stroke and 2.18 [0.52, 8.96] (P=0.282) for MI.

Table 3. Associations of Heme Oxygenase-1 Genotype With the Primary and Extended Cardiovascular End Points

Repeat Length GroupAdjustment
NoneAge and SexMultivariable*
HR (95% CI)P ValueHR (95% CI)P ValueHR (95% CI)P Value
Primary cardiovascular end point
 SS/SM0.49 (0.16, 1.55)0.2260.62 (0.20, 1.97)0.4200.68 (0.21, 2.15)0.507
 MM1.00 (ref)1.00 (ref)1.00 (ref)
 ML0.99 (0.59, 1.67)0.9711.15 (0.68, 1.95)0.5991.11 (0.65, 1.88)0.705
 LL4.78 (2.10, 10.88)<0.0015.46 (2.39, 12.50)<0.00016.33 (2.74, 14.64)<0.0001
 LL vs other4.90 (2.16, 11.13)<0.0015.45 (2.39, 12.42)<0.00016.33 (2.75, 14.59)<0.0001
Extended cardiovascular end point
 SS/SM0.39 (0.12, 1.23)0.1090.47 (0.15, 1.49)0.2020.50 (0.16, 1.57)0.235
 MM1.00 (ref)1.00 (ref)1.00 (ref)
 ML1.02 (0.64, 1.64)0.9251.20 (0.75, 1.92)0.4551.16 (0.72, 1.87)0.532
 LL5.07 (2.36, 10.88)<0.00015.88 (2.72, 12.68)<0.00016.55 (3.01, 14.30)<0.0001
 LL vs other5.21 (2.43, 11.14)<0.00015.87 (2.73, 12.63)<0.00016.56 (3.02, 14.26)<0.0001

The primary cardiovascular end point included nonfatal stroke, nonfatal myocardial infarction, and vascular death. The extended cardiovascular end point additionally included peripheral vascular disease and revascularization procedures.

*Multivariable adjustment was for age, sex, total and high-density lipoprotein cholesterol, current smoking, diabetes mellitus, systolic blood pressure, and body mass index.

CI indicates confidence interval; and HR, hazard ratio.

In sensitivity analyses, we used penalized cubic splines to examine the precise scale of relationship between VNTR length of each allele and CVD irrespective of predefined cut-offs. This gave significant results for the shorter allele (P=0.0073) and provided a post hoc confirmation of our a priorily fixed cut-off of 32 (Figure 2). When applying alternative and mostly lower cut-offs previously used in the literature (Table 1), findings were not significant, underscoring that high risk was confined to subjects homozygous for the longest HO-1 VNTRs.

Figure 2.

Figure 2. Penalized cubic spline fit of the association of variable number tandem repeat (VNTR) length on the shorter heme oxygenase-1 (HO-1) allele with the compound cardiovascular disease end point. Grey lines show the cut-offs we applied.

Finally, subjects in the LL group tended to experience atherosclerosis progression (incidence of new plaques or growth of existing ones) more frequently (82% versus 46%, odds ratio [95% CI], 4.72 [0.91, 36.68]; P=0.089) and showed a significantly larger change in the atherosclerosis score over 5 years (median difference in atherosclerosis score [interquartile range], 2.1 [0.8, 5.6] versus 0.0 [0.0, 2.2] mm; P=0.001), suggesting that the enhanced burden of CVD is at least in part mediated by accelerated atherogenesis. Subjects in the LL group also showed a trend toward elevated baseline levels of oxidized phospholipids (OxPL) on apolipoprotein B (apoB)-100 (median OxPL/apoB levels [interquartile range], 11364 [4160, 18330] versus 4844 [3174, 12284] relative light units; P=0.055). Results were similar when the Δatherosclerosis score and OxPL/apoB were log-transformed (P=0.014 and P=0.073, respectively). Differences between subjects in the LL group and the rest of the sample with regards to incident CVD, Δatherosclerosis score, and OxPL/apoB are summarized in Figure 3.

Figure 3.

Figure 3. Differences between subjects with the LL genotype and subjects with other genotypes regarding incident cardiovascular disease (CVD; 1995–2010), changes in the carotid atherosclerosis score (1995–2000), and oxidized phospholipids (OxPL)/apolipoprotein B (apoB) levels (measured in 1995). Tests were adjusted for age and sex.

To corroborate our main result, we gathered data from 3 additional prospective cohorts: The Cooperative Health Research in the Region of Augsburg (KORA) F3 and F4 studies, and the Salzburg Atherosclerosis Prevention program in subjects at High Individual Risk (SAPHIR) study. As is visible in Table 4, these cohorts differed in most baseline characteristics. In particular, the additional 3 cohorts had substantially lower prevalences of the LL genotype and also substantially lower CVD incidence rates (P=0.011 for heterogeneity after adjustment for age and sex). As a consequence, we were unable to perform a strict independent replication of our key result. However, when pooling data from all 4 studies, the subjects in the LL group versus other subjects remained at strongly and significantly elevated risk for CVD (HR [95% CI], 3.26 [1.50, 7.33]; P=0.004; 326 events in 7848 subjects). Moreover, when pooling data from the Bruneck and the SAPHIR study, for which data on an extended end point additionally including revascularization procedures and peripheral vascular disease were available, the LL group was also strongly associated with this end point (HR [95% CI], 3.98 [1.76, 9.03]; P<0.001; 275 events in 2524 subjects). Both of these associations remained similar and significant under extended multivariable adjustment.

Table 4. Comparison of Prospective Cohorts

StudyBruneckKORA F3KORA F4SAPHIRPany difference
Demographic variables
 Age, y62.73±11.1056.16±12.5355.15±12.9951.38±6.00<0.0001
 Female sex, n (%)411 (50.6)1348 (52.2)1451 (53.0)635 (37.1)<0.0001
Metabolic and lifestyle variables
 Diabetes mellitus, n (%)87 (10.7)170 (6.6)163 (5.9)54 (3.2)<0.0001
 HDL cholesterol, mg/dL58.71±16.1559.08±17.0556.18±14.4259.69±15.69<0.0001
 Total cholesterol, mg/dL230.00±42.56219.38±39.59216.28±39.09228.80±39.97<0.0001
 Systolic blood pressure, mm Hg148.27±20.74130.16±19.84121.82±18.32138.84±17.86<0.0001
 Current smoking, n (%)156 (19.6)481 (18.7)489 (17.8)332 (19.4)0.511
 Body mass index, kg/m225.64±3.8427.54±4.5527.44±4.7426.79±4.12<0.0001
HO-1 genotype frequencies
 S/SML35 (4.3)83 (3.2)65 (2.4)39 (2.3)0.001
 MM665 (81.9)2195 (84.9)2345 (85.6)1459 (85.2)
 ML101 (12.4)298 (11.5)316 (11.5)207 (12.1)
 LL11 (1.4)8 (0.3)14 (0.5)7 (0.4)
 Incident CVD events, n (%)132 (16.3)90 (3.5)34 (1.2)70 (4.1)<0.0001

Values are given as n (%) or as mean±SD. The S/SML genotype group subsumed subjects whose shorter allele had <23 tandem repeats.

CVD indicates cardiovascular disease; HDL, high-density lipoprotein; and HO-1, heme oxygenase-1.


In a prospective cohort study, we observed a substantially increased risk of CVD (hazard ratio [95% confidence interval], 5.45 (2.39, 12.42); P<0.0001) in subjects homozygous for long HO-1 VNTRs, indicating a recessive gene effect. This recessive nature of association is in line with experimental data, suggesting the shorter allele to be decisive for HO-1 upregulation in human umbilical vein endothelial cells.10 Excess risk in our study was restricted to a small segment of the population (LL genotype, 1.4%).

This is the first prospective study on the relationship of the HO-1 VNTR with CVD conducted in the general population. To the best of our knowledge, the previous studies were conducted in high-risk populations, such as patients with preexisting CVD, coronary stenting, or hemodialysis (Table 1). One Chinese study was population-based but cross-sectional in design.13 Many of the previous reports on this matter used lower VNTR cut-offs, most commonly 25 to 27. Of these, 3 large studies,25–26 including 1800 to 3000 patients, found no relationship between HO-1 VNTR repeat length and their primary end points restenosis25,26 or CAD,28 but a large number of smaller studies did. Putting these data in perspective with our study, it should be considered that HO-1 induction occurs in response to stress conditions,10,11,33 and a more severe deficit in HO-1 might be necessary in the general (low-risk) population to evoke deleterious effects, whereas a less severe deficit could suffice in higher-risk patients. This interpretation is consistent with several reports that found an association between HO-1 VNTR length and vascular end points only in high-risk sub groups, such as diabetic subjects or smokers.11,13,16,29

The dependency of HO-1 protein expression on HO-1 VNTR length has to date been investigated primarily in cell lines. It was found that baseline as well as oxidative stress-induced HO-1 protein levels decreased approximately monotonically parallel to increasing length of the shorter HO-1 allele.10 This extends earlier findings of reduced HO-1 transcriptional activity with increasing VNTR length.11,12 One study found lower increase of HO-1 protein in response to oxidative stress but higher HO-1 baseline expression in cells with long alleles,34 whereas another found higher HO-1 protein expression associated with short alleles only under conditions of oxidative stress.13 There is to date no direct study of this dependency in humans. However, it has been reported that diabetic subjects homozygous for long alleles had increased CAD risk, reduced bilirubin levels, and increased serum ferritin levels and that the association with CAD risk disappeared with multivariable adjustment for bilirubin and ferritin.27 These findings are consistent with reduced HO-1 activity in subjects with long alleles and also with reduced HO-1 activity potentially mediating the effect on CAD risk.

Several lines of evidence suggest that the key finding of our study is valid: (1) the association between HO-1 VNTR and CVD was of particular strength (HR, 5.45; lower confidence bound, 2.39) and highly significant (P=5.51×10–5). It would even retain significance in an exploratory setting, testing for all previously used VNTR cut-off values and adjusting for these multiple comparisons (Bonferroni corrected P=4.95×10–4). (2) The elevated CVD risk observed in the LL HO-1 group was robust in several sensitivity analyses (Table 3). (3) The LL group was at elevated CVD risk also in a pooled analysis of 7848 subjects. (4) Vascular protection conferred by HO-12,3 is impressively demonstrated by the prominent vascular damage observed in human HO-1 deficiency.8 (5) The deficit in HO-1 upregulation in response to cell stress with higher HO-1VNTR number rests on solid experimental evidence.1013(6) Subjects with the LL HO-1 genotype in our study had higher levels of OxPL/apoB (P=0.055), which is consistent with decreased HO-1 activity. (7) Finally, we observed a high risk of atherosclerosis progression in the LL HO-1 group, providing a pathophysiological explanation for the elevated CVD risk.

Strengths of our study include its prospective design with long-term high-quality follow-up and representativeness for the general population. Among its weaknesses is the limited number of subjects in extreme repeat length groups, a weakness that extends to the additional population-based cohorts that we used, which precluded subgroup analyses.

In conclusion, subjects with ≥32 tandem repeats on both HO-1 alleles represent a hitherto neglected vascular high-risk group featured by a substantial burden of CVD, amplified progression of atherosclerosis, and impaired antioxidant defense.

Nonstandard Abbreviations and Acronyms


coronary artery disease


cardiovascular disease


guanidine thymidine


heme oxygenase-1


oxidized phospholipids


variable number tandem repeat


The online-only Data Supplement is available with this article at

Correspondence to Stefan Kiechl, MD, Department of Neurology, Medical University Innsbruck, Anichstraße 35, 6020 Innsbruck, Austria. E-mail


  • 1. Ross R. Atherosclerosis–an inflammatory disease.N Engl J Med. 1999; 340:115–126.CrossrefMedlineGoogle Scholar
  • 2. Ryter SW, Alam J, Choi AM. Heme oxygenase-1/carbon monoxide: from basic science to therapeutic applications.Physiol Rev. 2006; 86:583–650.CrossrefMedlineGoogle Scholar
  • 3. Soares MP, Bach FH. Heme oxygenase-1: from biology to therapeutic potential.Trends Mol Med. 2009; 15:50–58.CrossrefMedlineGoogle Scholar
  • 4. Ishikawa K, Sugawara D, Wang Xp, Suzuki K, Itabe H, Maruyama Y, Lusis AJ. Heme oxygenase-1 inhibits atherosclerotic lesion formation in ldl-receptor knockout mice.Circ Res. 2001; 88:506–512.LinkGoogle Scholar
  • 5. Tulis DA, Durante W, Peyton KJ, Evans AJ, Schafer AI. Heme oxygenase-1 attenuates vascular remodeling following balloon injury in rat carotid arteries.Atherosclerosis. 2001; 155:113–122.CrossrefMedlineGoogle Scholar
  • 6. Duckers HJ, Boehm M, True AL, Yet SF, San H, Park JL, Clinton Webb R, Lee ME, Nabel GJ, Nabel EG. Heme oxygenase-1 protects against vascular constriction and proliferation.Nat Med. 2001; 7:693–698.CrossrefMedlineGoogle Scholar
  • 7. Lindenblatt N, Bordel R, Schareck W, Menger MD, Vollmar B. Vascular heme oxygenase-1 induction suppresses microvascular thrombus formation in vivo.Arterioscler Thromb Vasc Biol. 2004; 24:601–606.LinkGoogle Scholar
  • 8. Yachie A, Niida Y, Wada T, Igarashi N, Kaneda H, Toma T, Ohta K, Kasahara Y, Koizumi S. Oxidative stress causes enhanced endothelial cell injury in human heme oxygenase-1 deficiency.J Clin Invest. 1999; 103:129–135.CrossrefMedlineGoogle Scholar
  • 9. Ishikawa K, Navab M, Lusis AJ. Vasculitis, atherosclerosis, and altered HDL composition in heme-oxygenase-1-knockout mice.Int J Hypertens. 2012; 2012:948203.CrossrefMedlineGoogle Scholar
  • 10. Taha H, Skrzypek K, Guevara I, et al. Role of heme oxygenase-1 in human endothelial cells: lesson from the promoter allelic variants.Arterioscler Thromb Vasc Biol. 2010; 30:1634–1641.LinkGoogle Scholar
  • 11. Chen YH, Lin SJ, Lin MW, Tsai HL, Kuo SS, Chen JW, Charng MJ, Wu TC, Chen LC, Ding YA, Pan WH, Jou YS, Chau LY. Microsatellite polymorphism in promoter of heme oxygenase-1 gene is associated with susceptibility to coronary artery disease in type 2 diabetic patients.Hum Genet. 2002; 111:1–8.CrossrefMedlineGoogle Scholar
  • 12. Yamada N, Yamaya M, Okinaga S, Nakayama K, Sekizawa K, Shibahara S, Sasaki H. Microsatellite polymorphism in the heme oxygenase-1 gene promoter is associated with susceptibility to emphysema.Am J Hum Genet. 2000; 66:187–195.CrossrefMedlineGoogle Scholar
  • 13. Chen M, Zhou L, Ding H, Huang S, He M, Zhang X, Cheng L, Wang D, Hu FB, Wu T. Short (GT) (n) repeats in heme oxygenase-1 gene promoter are associated with lower risk of coronary heart disease in subjects with high levels of oxidative stress.Cell Stress Chaperones. 2012; 17:329–338.CrossrefMedlineGoogle Scholar
  • 14. Morita T. Heme oxygenase and atherosclerosis.Arterioscler Thromb Vasc Biol. 2005; 25:1786–1795.LinkGoogle Scholar
  • 15. Exner M, Schillinger M, Minar E, Mlekusch W, Schlerka G, Haumer M, Mannhalter C, Wagner O. Heme oxygenase-1 gene promoter microsatellite polymorphism is associated with restenosis after percutaneous transluminal angioplasty.J Endovasc Ther. 2001; 8:433–440.CrossrefMedlineGoogle Scholar
  • 16. Kaneda H, Ohno M, Taguchi J, Togo M, Hashimoto H, Ogasawara K, Aizawa T, Ishizaka N, Nagai R. Heme oxygenase-1 gene promoter polymorphism is associated with coronary artery disease in Japanese patients with coronary risk factors.Arterioscler Thromb Vasc Biol. 2002; 22:1680–1685.LinkGoogle Scholar
  • 17. Schillinger M, Exner M, Mlekusch W, Domanovits H, Huber K, Mannhalter C, Wagner O, Minar E. Heme oxygenase-1 gene promoter polymorphism is associated with abdominal aortic aneurysm.Thromb Res. 2002; 106:131–136.CrossrefMedlineGoogle Scholar
  • 18. Chen YH, Chau LY, Lin MW, Chen LC, Yo MH, Chen JW, Lin SJ. Heme oxygenase-1 gene promotor microsatellite polymorphism is associated with angiographic restenosis after coronary stenting.Eur Heart J. 2004; 25:39–47.CrossrefMedlineGoogle Scholar
  • 19. Endler G, Exner M, Schillinger M, Marculescu R, Sunder-Plassmann R, Raith M, Jordanova N, Wojta J, Mannhalter C, Wagner OF, Huber K. A microsatellite polymorphism in the heme oxygenase-1 gene promoter is associated with increased bilirubin and HDL levels but not with coronary artery disease.Thromb Haemost. 2004; 91:155–161.CrossrefMedlineGoogle Scholar
  • 20. Funk M, Endler G, Schillinger M, Mustafa S, Hsieh K, Exner M, Lalouschek W, Mannhalter C, Wagner O. The effect of a promoter polymorphism in the heme oxygenase-1 gene on the risk of ischaemic cerebrovascular events: the influence of other vascular risk factors.Thromb Res. 2004; 113:217–223.CrossrefMedlineGoogle Scholar
  • 21. Schillinger M, Exner M, Minar E, Mlekusch W, Müllner M, Mannhalter C, Bach FH, Wagner O. Heme oxygenase-1 genotype and restenosis after balloon angioplasty: a novel vascular protective factor.J Am Coll Cardiol. 2004; 43:950–957.CrossrefMedlineGoogle Scholar
  • 22. Dick P, Schillinger M, Minar E, Mlekusch W, Amighi J, Sabeti S, Schlager O, Raith M, Endler G, Mannhalter C, Wagner O, Exner M. Haem oxygenase-1 genotype and cardiovascular adverse events in patients with peripheral artery disease.Eur J Clin Invest. 2005; 35:731–737.CrossrefMedlineGoogle Scholar
  • 23. Gulesserian T, Wenzel C, Endler G, Sunder-Plassmann R, Marsik C, Mannhalter C, Iordanova N, Gyöngyösi M, Wojta J, Mustafa S, Wagner O, Huber K. Clinical restenosis after coronary stent implantation is associated with the heme oxygenase-1 gene promoter polymorphism and the heme oxygenase-1 +99G/C variant.Clin Chem. 2005; 51:1661–1665.CrossrefMedlineGoogle Scholar
  • 24. Li P, Elrayess MA, Gomma AH, Palmen J, Hawe E, Fox KM, Humphries SE. The microsatellite polymorphism of heme oxygenase-1 is associated with baseline plasma IL-6 level but not with restenosis after coronary in-stenting.Chin Med J (Engl). 2005; 118:1525–1532.MedlineGoogle Scholar
  • 25. Wijpkema JS, van Haelst PL, Monraats PS, Bruinenberg M, Zwinderman AH, Zijlstra F, van der Steege G, de Winter RJ, Doevendans PA, Waltenberger J, Jukema JW, Tio RA. Restenosis after percutaneous coronary intervention is associated with the angiotensin-II type-1 receptor 1166A/C polymorphism but not with polymorphisms of angiotensin-converting enzyme, angiotensin-II receptor, angiotensinogen or heme oxygenase-1.Pharmacogenet Genomics. 2006; 16:331–337.CrossrefMedlineGoogle Scholar
  • 26. Tiroch K, Koch W, von Beckerath N, Kastrati A, Schömig A. Heme oxygenase-1 gene promoter polymorphism and restenosis following coronary stenting.Eur Heart J. 2007; 28:968–973.CrossrefMedlineGoogle Scholar
  • 27. Chen YH, Chau LY, Chen JW, Lin SJ. Serum bilirubin and ferritin levels link heme oxygenase-1 gene promoter polymorphism and susceptibility to coronary artery disease in diabetic patients.Diabetes Care. 2008; 31:1615–1620.CrossrefMedlineGoogle Scholar
  • 28. Lüblinghoff N, Winkler K, Winkelmann BR, Seelhorst U, Wellnitz B, Boehm BO, März W, Hoffmann MM. Genetic variants of the promoter of the heme oxygenase-1 gene and their influence on cardiovascular disease (the Ludwigshafen Risk and Cardiovascular Health study).BMC Med Genet. 2009; 10:36.CrossrefMedlineGoogle Scholar
  • 29. Bai C-H, Chen J-R, Chiu H-C, Chou C-C, Chau L-Y, Pan W-H. Shorter GT repeat polymorphism in the heme oxygenase-1 gene promoter has protective effect on ischemic stroke in dyslipidemia patients.J Biomed Sci. 2010; 17:12.Google Scholar
  • 30. Wu MM, Chiou HY, Chen CL, Wang YH, Hsieh YC, Lien LM, Lee TC, Chen CJ. GT-repeat polymorphism in the heme oxygenase-1 gene promoter is associated with cardiovascular mortality risk in an arsenic-exposed population in northeastern Taiwan.Toxicol Appl Pharmacol. 2010; 248:226–233.CrossrefMedlineGoogle Scholar
  • 31. Chen YH, Hung SC, Tarng DC. Length polymorphism in heme oxygenase-1 and cardiovascular events and mortality in hemodialysis patients.Clin J Am Soc Nephrol. 2013; 8:1756–1763.CrossrefMedlineGoogle Scholar
  • 32. Gregorek AC, Gornik KC, Polancec DS, Dabelic S. GT microsatellite repeats in the heme oxygenase-1 gene promoter associated with abdominal aortic aneurysm in Croatian patients.Biochem Genet. 2013; 51:482–492.CrossrefMedlineGoogle Scholar
  • 33. Otterbein LE, Choi AM. Heme oxygenase: colors of defense against cellular stress.Am J Physiol Lung Cell Mol Physiol. 2000; 279:L1029–L1037.CrossrefMedlineGoogle Scholar
  • 34. Romanoski CE, Che N, Yin F, Mai N, Pouldar D, Civelek M, Pan C, Lee S, Vakili L, Yang WP, Kayne P, Mungrue IN, Araujo JA, Berliner JA, Lusis AJ. Network for activation of human endothelial cells by oxidized phospholipids: a critical role of heme oxygenase 1.Circ Res. 2011; 109:e27–e41.LinkGoogle Scholar


Heme oxygenase-1 is a key antioxidant and cytoprotective enzyme, and a repeat length polymorphism in its gene promoter region impacts its expression. We found that this polymorphism is associated with cardiovascular risk such that subjects with high repeat lengths on both heme oxygenase-1 alleles suffer a substantially elevated risk. Moreover, we found evidence that oxidative stress and atherosclerosis at least partly mediate this risk elevation. The prospective population-based framework of the Bruneck Study with its high-quality data assessment allowed, for the first time, an investigation of this association both longitudinally and in the general population. This work may delimit a previously underappreciated cardiovascular high-risk group that merits particular preventive attention.