[Clioquinol use for Dientamoeba fragilis infections is questionable]. / Clioquinol voor Dientamoeba fragilis-infectie discutabel.

Clioquinol is used for treatment of amoebiasis and infection with Dientamoeba fragilis. In a guideline of the Dutch Working Party on Antibiotic Policy, clioquinol is recommended as a first-choice treatment for Dientamoeba fragilis. This drug, however, is associated with subacute myelo-optico-neuropathy (SMON). It was withdrawn from the market worldwide in 1985 by manufacturer Ciba-Geigy. Although the Dutch Medicines Evaluation Board has registered no products for systemic use of clioquinol since then, the drug is available as a pharmacy-compounded drug and the last few years the use of clioquinol in the Netherlands has risen again. The Netherlands Pharmacovigilance Centre Lareb has received a growing number of reports of adverse drug reactions (ADRs) associated with the use of clioquinol, including nervous system disorder ADRs occurring at recommended dosages. Therefore, we debate the use of clioquinol as a first-choice treatment option for Dientamoeba fragilis.

The concordance between self-reported medication use and pharmacy records in pregnant women.

PURPOSE: Several studies have been conducted to assess determinants affecting the performance or accuracy of self-reports. These studies are often not focused on pregnant women, or medical records were used as a data source where it is unclear if medications have been dispensed. Therefore, our objective was to evaluate the concordance between self-reported medication data and pharmacy records among pregnant women and its determinants. METHODS: We conducted a population-based cohort study within the Generation R study, in 2637 pregnant women. The concordance between self-reported medication data and pharmacy records was calculated for different therapeutic classes using Yule's Y. We evaluated a number of variables as determinant of discordance between both sources through univariate and multivariate logistic regression analysis. RESULTS: The concordance between self-reports and pharmacy records was moderate to good for medications used for chronic conditions, such as selective serotonin reuptake inhibitors or anti-asthmatic medications (0.88 and 0.68, respectively). Medications that are used occasionally, such as antibiotics, had a lower concordance (0.51). Women with a Turkish or other non-Western background were more likely to demonstrate discordance between pharmacy records and self-reported data compared with women with a Dutch background (Turkish: odds ratio, 1.63; 95% confidence interval, 1.16-2.29; other non-Western: odds ratio, 1.33; 95% confidence interval, 1.03-1.71). CONCLUSIONS: Further research is needed to assess how the cultural or ethnic differences may affect the concordance or discordance between both medication sources. The results of this study showed that the use of multiple sources is needed to have a good estimation of the medication use during pregnancy.

Risk of cancer in patients on insulin glargine and other insulin analogues in comparison with those on human insulin: results from a large population-based follow-up study.

AIMS/HYPOTHESIS: Several publications suggest an association between certain types of insulin and cancer, but with conflicting results. We investigated whether insulin glargine (A21Gly,B31Arg,B32Arg human insulin) is associated with an increased risk of cancer in a large population-based cohort study. METHODS: Data for this study were obtained from dispensing records from community pharmacies individually linked to hospital discharge records from 2.5 million individuals in the Netherlands. In a cohort of incident users of insulin, the association between insulin glargine and other insulin analogues, respectively, and cancer was analysed in comparison with human insulin using Cox proportional hazard models with cumulative duration of drug use as a time-varying determinant. The first hospital admission with a primary diagnosis of cancer was considered as the main outcome; secondary analyses were performed with specific cancers as outcomes. RESULTS: Of the 19,337 incident insulin users enrolled, 878 developed cancer. Use of insulin glargine was associated with a lower risk of malignancies in general in comparison with human insulin (HR 0.75, 95% CI 0.71, 0.80). In contrast, an increased risk was found for breast cancer (HR 1.58, 95% CI 1.22, 2.05). Dose-response relationships could not be identified. CONCLUSION/INTERPRETATION: Users of insulin glargine and users of other insulin analogues had a lower risk of cancer in general than those using human insulin. Both associations might be a consequence of residual confounding, lack of adherence or competing risk. However, as in previous studies, we demonstrated an increased risk of breast cancer in users of insulin glargine in comparison with users of human insulin.

Statin use is associated with reduced incidence and progression of knee osteoarthritis in the Rotterdam study.

BACKGROUND: Osteoarthritis is the most frequent chronic joint disease causing pain and disability. Besides biomechanical mechanisms, the pathogenesis of osteoarthritis may involve inflammation, vascular alterations and dysregulation of lipid metabolism. As statins are able to modulate many of these processes, this study examines whether statin use is associated with a decreased incidence and/or progression of osteoarthritis. METHODS: Participants in a prospective population-based cohort study aged 55 years and older (n=2921) were included. x-Rays of the knee/hip were obtained at baseline and after on average 6.5 years, and scored using the Kellgren and Lawrence score for osteoarthritis. Any increase in score was defined as overall progression (incidence and progression). Data on covariables were collected at baseline. Information on statin use during follow-up was obtained from computerised pharmacy databases. The overall progression of osteoarthritis was compared between users and non-users of statins. Using a multivariate logistic regression model with generalised estimating equation, OR and 95% CI were calculated after adjusting for confounding variables. RESULTS: Overall progression of knee and hip osteoarthritis occurred in 6.9% and 4.7% of cases, respectively. The adjusted OR for overall progression of knee osteoarthritis in statin users was 0.43 (95% CI 0.25 to 0.77, p=0.01). The use of statins was not associated with overall progression of hip osteoarthritis. CONCLUSIONS: Statin use is associated with more than a 50% reduction in overall progression of osteoarthritis of the knee, but not of the hip.

Incidence, treatment, and case-fatality of non-traumatic subarachnoid haemorrhage in the Netherlands.

BACKGROUND: Non-traumatic subarachnoid haemorrhage (SAH) is a devastating disorder and in the majority of cases it is caused by rupture of an intracranial aneurysm. No actual data are available on the incidence of non-traumatic SAH and aneursymal SAH (aSAH) in the Netherlands and little is known about treatment patterns of aSAH. Our purpose was therefore to assess the incidence, treatment patterns, and case-fatality of non-traumatic (a)SAH within the Dutch general population. METHODS: Two population based data sources were used for this retrospective cohort study. One was the nationwide hospital discharge registry (National Medical Registration, LMR). Cases were patients hospitalized for SAH (ICD-9-code 430) in 2001-2005. The second source was the Integrated Primary Care Information (IPCI) database, a medical record database allowing for case validation. Cases were patients with validated non-traumatic (a)SAH in 1996-2006. Incidence, treatment, and case-fatality were assessed. RESULTS: The incidence rate (IR) of non-traumatic SAH was 7.12 per 100,000 PY (95%CI: 6.94-7.31) and increased with age. The IR of aSAH was 3.78 (95%CI: 2.98-4.72). Women had a twofold increased risk of non-traumatic SAH; this difference appeared after the fourth decade. Non-traumatic SAH fatality was 30% (95%CI: 29-31%). Of aSAH patients 64% (95%CI: 53-74%) were treated with a clipping procedure, and 26% (95%CI: 17-37%) with coiling. CONCLUSION: Non-traumatic SAH is a rare disease with substantial case-fatality; rates in the Netherlands are similar to other countries. Case-fatality is also similar as well as age and sex patterns in incidence.

Analysis of individual drug use as a time-varying determinant of exposure in prospective population-based cohort studies.

In pharmaco-epidemiology, the use of drugs is the determinant of interest when studying exposure-outcome associations. The increased availability of computerized information about drug use on an individual basis has greatly facilitated analyses of drug effects on a population-based scale. It seems likely that many negative findings in the early days of pharmaco-epidemiology can be explained by non-differential misclassification because of too simple (yes/no) exposure measures. In this paper, the authors discuss the importance of an adequate definition of drug exposure in pharmaco-epidemiological research and how this time-varying determinant can be analyzed in cohort studies. To reduce the risk of non-differential misclassification, a precise definition of exposure is mandatory and it is important to distinguish the complete follow-up period of a population into mutually exclusive episodes of non-use, past use and current use for each individual. By analyzing exposure to drugs as a time-dependent variable in a Cox regression model, cohort studies with complete coverage of all filled prescriptions can provide us with valid and precise risk estimates of drug-outcome associations. However, such estimates may be biased in the presence of time-dependent confounders which are themselves affected by prior exposure.

Hedgehog-interacting protein is a COPD susceptibility gene: the Rotterdam Study.

The Hedgehog signalling pathway plays an important role in lung morphogenesis and cellular responses to lung injury. A genome-wide association study has demonstrated that two single nucleotide polymorphisms (SNPs) near the Hedgehog-interacting protein (Hip) gene, SNP identifiers rs1828591 and rs13118928, are associated with risk of chronic obstructive pulmonary disease (COPD). The aim of the present study was to validate the observed association between genetic variation near the Hip gene and COPD, and to investigate whether risk estimates were modified by smoking behaviour. The association between the Hip gene SNPs and COPD was investigated in the Rotterdam Study by logistic regression analyses, adjusted for several covariates. In addition, an association meta-analysis was performed that included data from the genome-wide association study on COPD. Both SNPs were significantly associated with risk of COPD (OR 0.80; 95% CI 0.72-0.91). Homozygosity for the minor G allele resulted in a decreased risk of COPD of approximately 40% (95% CI 0.47-0.78). There was a significant interaction with the number of pack-years of smoking (p = 0.004). The meta-analysis yielded an odds ratio for COPD of 0.80 per additional G allele (p = 3.4 x 10(-9)). Genetic variation near the Hip gene was significantly associated with risk of COPD, depending on the number of pack-years of smoking.

Evaluation of serological trials submitted for annual re-licensure of influenza vaccines to regulatory authorities between 1992 and 2002.

BACKGROUND: As part of the regulatory requirements, serological evaluation of trivalent inactivated influenza vaccines must be performed before annual re-licensure in the European Union. These studies are typically set up as uncontrolled, open label trials including 2 groups of at least 50 healthy adults and healthy elderly. METHODS: The serological data submitted to the Dutch Medicines Evaluation Board (MEB) for annual re-licensure purposes between 1992 and 2002, were analysed with respect to their ability to assess the immunogenic properties of the vaccines. The trials in this meta-analysis were selected by strictly applying the inclusion and exclusion criteria described in the Committee of Human Medicinal Products (CHMP) Note for Guidance on harmonisation of requirements for influenza vaccines. To select the final dataset additional exclusion criteria were defined: age outside the inclusion criterion of the trial, incomplete demographics, co-morbid conditions, antibody determination by SRH assay, incomplete dataset and sample size smaller than 50 subjects. RESULTS: Out of 51 trials retrieved from the archives, 48 age-defined trials including 2510 adults and 2008 elderly fulfilled all the in- and exclusion criteria. A large proportion of vaccinees already met the threshold for seroprotection at baseline. Post-vaccination, the serological response was shown to be age dependent. Previous influenza vaccinations significantly affected pre-vaccination but not post-vaccination titres. CONCLUSIONS: The annual update trials performed for regulatory purposes have serious methodological limitations, which affect their ability to identify influenza vaccines with low immunogenicity. To establish clinical (protective) efficacy different trials and different assessment criteria are needed.

No modification of the beneficial effect of NSAIDs on colorectal cancer by CYP2C9 genotype.

BACKGROUND: CYP2C9 enzymes are involved in non-steroidal anti-inflammatory drug (NSAID) metabolism. Therefore, we investigated whether CYP2C9*2 and *3 variant alleles, encoding for enzymes with lower activity, increased the protective effect of NSAIDs on colorectal cancer. METHODS: Individual and combined associations of NSAIDs and CYP2C9*2 and *3 variant alleles with colorectal cancer were studied in 7757 Caucasian individuals of The Rotterdam Study, a population-based prospective cohort since 1990. Additive and multiplicative effect modification models were used to examine drug-gene interactions. RESULTS: There were 212 incident cases of colorectal cancer during follow-up. A reduced risk of colorectal cancer was observed in individuals who used NSAIDs for more than a year (HR 0.45; 95% CI 0.28 to 0.71), and in carriers of an CYP2C9 variant allele associated with lower enzymatic activity (HR 0.67; 95% CI 0.47 to 0.96). The combination of both determinants was associated with a further risk reduction but without synergy. CONCLUSION: Both NSAID use and CYP2C9*2 and/ or *3 carriage are associated with a reduced risk of colorectal cancer. However, no interaction between the determinants was found, which might indicate independent pathophysiological mechanisms.

Referral and treatment patterns for complex regional pain syndrome in the Netherlands.

BACKGROUND: Patients with complex regional pain syndrome (CRPS) are seen and treated by a variety of physicians. The present study aims to describe referral and treatment patterns for CRPS patients in the Netherlands. METHODS: Patients, who were selected (1996-2005) from an electronic general practice (GP) database (Integrated Primary Care Information Project), were invited for study participation, involving diagnosis verification (International Association for the Study of Pain criteria) and assessment of referrals and treatment through information retrieved from GP journals, patients' questionnaires, pharmacy dispensing lists and specialist letters if available. RESULTS: One hundred and two patients were included. Sixty-one percent had presented first at the GP, while 80% subsequently consulted one or more medical specialists, most frequently an anesthetist (55% of the cases) or a specialist in rehabilitation medicine (41%). Over 90% of the patients received oral or topical pharmacotherapy, 45% received intravenous therapy, 89% received non-invasive therapy (i.e. physiotherapy) and 18% received nerve blocks. Analgesics and free radical scavengers were administered early during CRPS, while vasodilating drugs and drugs against neuropathic pain (antidepressants and anti-epileptics) were administered later on. Pharmacotherapy was usually initiated by a medical specialist. CONCLUSION: The Dutch treatment guidelines, issued in 2006, recommend free radical scavenger prescription (plus physiotherapy) as the initial treatment step for CRPS. Until 2005 only half of the patients received a scavenger within 3 months after disease onset, and the majority presents first at the GP, in particular GPs may be encouraged to initiate treatment with scavengers, while waiting for the results of further specialist consultation.

Genetic variation in the CYP2D6 gene is associated with a lower heart rate and blood pressure in beta-blocker users.

Several beta-blockers are metabolized by the polymorphic enzyme cytochrome P450 2D6 (CYP2D6). CYP2D6*4 is the main polymorphism leading to decreased enzyme activity. The clinical significance of impaired elimination of beta-blockers is controversial, and most studies suffer from inclusion of small numbers of poor metabolizers (PMs) of CYP2D6. In this study, the association between CYP2D6*4 and blood pressure or heart rate was examined in 1,533 users of beta-blockers in the Rotterdam Study, a population-based cohort study. In CYP2D6 *4/*4 PMs, the adjusted heart rate in metoprolol users was 8.5 beats/min lower compared with *1/*1 extensive metabolizers (EMs) (P < 0.001), leading to an increased risk of bradycardia in PMs (odds ratio = 3.86; 95% confidence interval 1.68-8.86; P = 0.0014). The diastolic blood pressure in PMs was 5.4 mm Hg lower in users of beta-blockers metabolized by CYP2D6 (P = 0.017) and 4.8 mm Hg lower in metoprolol users (P = 0.045) compared with EMs. PMs are at increased risk of bradycardia.

Estrogens and the risk of complex regional pain syndrome (CRPS).

OBJECTIVE: Since complex regional pain syndrome (CRPS) shows a clear female predominance, we investigated the association between the cumulative as well as current exposure to estrogens, and CRPS. METHODS: A population-based case-control study was conducted in the Integrated Primary Care Information (IPCI) project in the Netherlands. Cases were identified from electronic records (1996-2005) and included if they were confirmed during a visit (using International Association for the Study of Pain Criteria), or had been diagnosed by a specialist. Controls were matched to cases on gender, age, calendar time, and injury. Measures of cumulative endogenous estrogen exposure were obtained by questionnaire and included age of menarche and menopause, menstrual life, and cumulative months of pregnancy and breast-feeding. Current estrogen exposure at CRPS onset was retrieved from the electronic medical records and determined by current pregnancy or by the use of oral contraceptive (OC) drugs or hormonal replacement therapy (HRT). RESULTS: Hundred and forty-three female cases (1493 controls) were included in analyses on drug use and pregnancies, while cumulative endogenous estrogen exposure was studied in 53 cases (58 controls) for whom questionnaire data were available. There was no association between CRPS and either cumulative endogenous estrogen exposure, OC, or HRT use. CRPS onset was increased during the first 6 months after pregnancy (OR: 5.6, 95%CI: 1.0-32.4), although based on small numbers. DISCUSSION: We did not find an association between CRPS onset and cumulative endogenous estrogen exposure or current OC or HRT use, but more powered studies are needed to exclude potential minor associations.

Protective effect of NSAIDs on cancer and influence of COX-2 C(-765G) genotype.

PURPOSE: Inhibition of COX-2 enzymes is a frequently suggested mechanism for the beneficial effects of NSAIDs on carcinogenesis. The aim of this study was to explore the role of cumulative NSAID use on four common non-skin related cancers and modification by COX-2 G(-765)C genotype. PATIENTS AND METHODS: 7621 participants of The Rotterdam Study were included. In a mean follow up period of 10 years, 720 colorectal, lung, breast or prostate cancers occurred. Cumulative NSAID use was calculated per NSAID class. Individual associations of NSAID use and COX-2 G(-765)C genotype on cancer risk were explored with Cox' proportional hazard models. Next, the association of NSAIDs and cancer stratified by COX-2 genotype was studied. Finally, the effect of combinations of NSAID use and COX-2 genotype on survival times was investigated. RESULTS: All NSAID classes were associated with a reduced risk of colorectal cancer but not of other cancers. No associations between COX-2 genotype and incident cancer, overall or cancer specific mortality were observed. COX-selective NSAIDs showed modest further risk reduction. Survival times were more than twice as long for carriers of a COX-2 C(-765) allele with colorectal cancer who used NSAIDs in the five years prior to diagnosis than for patients homozygous for the wild type (G(-765)) without NSAID use (p = 0.007). CONCLUSION: Our results confirm the protective effect of NSAID use on colorectal cancer. Individuals diagnosed with colorectal cancer who carry a COX-2 C(-765) allele and are on NSAIDs have an increased survival in comparison to non-users with the wild type (G(-765)).

Interaction between polymorphisms in the renin-angiotensin-system and angiotensin-converting enzyme inhibitor or beta-blocker use and the risk of myocardial infarction and stroke.

This study investigates whether the interaction between angiotensin-converting enzyme (ACE) inhibitors or beta-blockers and the ACE insertion/deletion (I/D) polymorphism or angiotensin receptor II type 1 (AGTR1) 573C/T polymorphism modifies the risk of myocardial infarction (MI) or stroke. In total, 4097 subjects with hypertension were included in this study. The drug-gene interaction on the risk of MI or stroke was determined with a Cox proportional hazard model. The risk of MI was reduced in current users of ACE inhibitors with the AGTR1 573CT or CC genotype compared to ACE inhibitors with the AGTR1 573TT genotype (synergy index (SI):0.32; 95% confidence interval (CI): 0.14-0.70). No significant drug-gene interaction was found on the risk of stroke (SI:0.82; 95% CI: 0.44-1.52) or in beta-blocker users. Also, no significant drug-gene interaction was found with the ACE I/D polymorphism. In conclusion, subjects with at least one copy of the AGTR1 573C allele might have more benefit from ACE inhibitor therapy.

Vitamin K epoxide reductase complex subunit 1 (VKORC1) polymorphism and aortic calcification: the Rotterdam Study.

OBJECTIVE: Besides effects on hemostasis, vitamin K-dependent proteins play a role in bone mineralization and arterial calcification. We investigated the association between the VKORC1 1173C>T polymorphism and calcification of the aortic far wall in a large population-based cohort. METHODS AND RESULTS: Aortic calcification was diagnosed by radiographic detection of calcified deposits in the abdominal aorta. In all cohort members for whom DNA was available, the C1173T SNP of VKORC1 (rs9934438) was determined. With multivariable logistic regression analysis the association between this polymorphism and the risk of aortic calcification was calculated, adjusted for potential confounders. The T allele frequency of the VKORC1 1173C>T polymorphism was 38.8%. 1185 (37.2%) persons were homozygous CC, 1529 (48,0%) were heterozygous CT and 473 (14.8%) were homozygous TT. Persons with at least one T-allele had a statistically significant 19% (95% CI 2 to 40%) risk increase of calcification of the aortic far wall compared to CC homozygous persons, adjusted for age and gender. CONCLUSIONS: The T-allele of the VKORC1 1173C>T polymorphism was associated with a significantly higher risk of aortic calcification in Whites.

Cytochrome P450 2C9 *2 and *3 polymorphisms and the dose and effect of sulfonylurea in type II diabetes mellitus.

Sulfonylurea hypoglycemics are mainly metabolized by the cytochrome P450 2C9 (CYP2C9) enzyme. The CYP2C9*2 and *3 polymorphisms encode proteins with less enzymatic activity and are correlated with elevated serum levels of sulfonylurea, as demonstrated in healthy volunteers. In this study, the effect of these variants is described for patients with diabetes mellitus treated with sulfonylurea. Associations between CYP2C9 polymorphisms, prescribed doses of sulfonylurea, and change in glucose levels after the start of sulfonylurea therapy were assessed in all patients with incident diabetes mellitus starting on sulfonylurea therapy in the Rotterdam Study, a population-based cohort study of 7,983 elderly people. In CYP2C9*3 allele carriers using tolbutamide, the prescribed dose was lower compared to patients with the wild-type CYP2C9 genotype. No differences in the prescribed dose were found in tolbutamide users with the CYP2C9*1/*2 or CYP2C9*2/*2 genotype compared to wild-type patients or in patients using other sulfonylurea. In CYP2C9*3 allele carriers, the mean decrease in fasting serum glucose levels after the start of tolbutamide therapy was larger than in patients with the wild-type genotype, although not statistically significant. Patients with diabetes mellitus who are carriers of a CYP2C9*3 allele require lower doses of tolbutamide to regulate their serum glucose levels compared to patients with the wild-type genotype.

Estrogen receptor alpha polymorphisms and postmenopausal breast cancer risk.

BACKGROUND: The estrogen receptor alpha (ESR1) is a mediator of estrogen response in the breast. The most studied variants in this gene are the PvuII and XbaI polymorphisms, which have been associated to lower sensitivity to estrogen. We evaluated whether these polymorphisms were associated with breast cancer risk by means of an association study in a population of Caucasian postmenopausal women from the Rotterdam study and a meta-analysis of published data. METHODS: The PvuII and XbaI polymorphisms were genotyped in 3,893 women participants of the Rotterdam Study. Baseline information was obtained through a questionnaire. We conducted logistic regression analyses to assess the risk of breast cancer by each of the ESR1 genotypes. Meta-analyses of all publications on these relations were done by retrieving literature from Pubmed and by further checking the reference lists of the articles obtained. RESULTS: There were 38 women with previously diagnosed breast cancer. During follow-up, 152 were additionally diagnosed. The logistic regression analyses showed no difference in risk for postmenopausal breast cancer in carriers of the PvuII or XbaI genotypes neither in overall, incident or prevalent cases. No further evidence of a role of these variants was found in the meta-analysis. CONCLUSIONS: Our results suggest that the ESR1 polymorphisms do not play a role in breast cancer risk in Caucasian postmenopausal women.

IGF-1 CA repeat variant and breast cancer risk in postmenopausal women.

IGF-I is an important growth factor for the mammary gland. We evaluated the relationship of the IGF-I CA(n) polymorphism with breast cancer risk in Caucasian postmenopausal women and performed a meta-analysis of published data. The IGF-I CA(n) polymorphism was genotyped in 4091 from the Rotterdam Study. A disease-free survival analysis was performed along with a meta-analysis of all available data on IGF-I CA(n) polymorphism and breast cancer risk. During follow-up 159 women were diagnosed with breast cancer. The disease-free survival analysis adjusted for age at entry, age at menopause, body mass index and waist hip ratio yielded a HR=0.97 (95% CI=0.59-1.58) for CA(19) non-carriers against carriers. The meta-analysis using the random-effects model gave a pooled OR of 1.26 (95% CI=0.95-1.82) for IGF-I CA(19) non-carriers versus CA(19) homozygous carriers. According to these results, the IGF-I CA(19) promoter polymorphism is not likely to predict the risk of breast cancer.

Pharmacogenetic interactions of three candidate gene polymorphisms with ACE-inhibitors or beta-blockers and the risk of atherosclerosis.

AIMS: To investigate whether the angiotensin-converting enzyme (ACE) insertion/deletion (I/D), angiotensinogen M235T or angiotensin II receptor type 1 573C/T polymorphism modify the risk of atherosclerosis associated with beta-blocker or ACE-inhibitor therapy. METHODS: Data were used from the Rotterdam Study, a population-based prospective cohort study in the Netherlands, which started in 1990 and included 7983 subjects of >or= 55 years. In this study, 2216 subjects with hypertension were included. Three subclinical measurements were used for atherosclerosis, i.e. peripheral arterial disease, carotid atherosclerosis and aortic atherosclerosis. The interaction between antihypertensive drugs and genetic polymorphisms on the risk of atherosclerosis was determined with binary logistic regression analysis. RESULTS: The risk of aortic atherosclerosis associated with long-term (>or=4 years) beta-blocker treatment compared with no use of beta-blockers was higher in subjects with the TT genotype than in subjects with the MM genotype of the AGT gene [synergy index (SI) = 3.36; 95% confidence interval (CI) 1.14, 9.97]. The risk of carotid atherosclerosis associated with long-term ACE-inhibitor treatment compared with no use of ACE-inhibitors was lower in subjects with the TT genotype than in subjects with the MM genotype of the AGT gene (SI = 0.20; 95% CI 0.04, 0.95). CONCLUSION: Overall, the risk of atherosclerosis in hypertensives taking a beta-blocker or ACE-inhibitor-based regimen was not strongly modified by any of the three candidate gene polymorphisms.