Nadia Obi

Dr. Nadia Obi

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Research Focus & Metrics

Academic Career Length

18Years (2009-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2019 in The American Journal of Clinical Nutrition
Verified
Journal Article
Closed access
AJAudrey Jung
Audrey Jung
XCXinting Cai
Xinting Cai
KTKathrin Thoene
Kathrin Thoene
NONadia Obi
Nadia Obi
SJStefanie Jaskulski
Stefanie Jaskulski
JCJenny Chang-Claude
Jenny Chang-Claude
There is a paucity of information on the prevalence of dietary supplement use in breast cancer survivors. Only a few studies have examined the impact of dietary supplements, particularly antioxidants, on breast cancer prognosis and the results are inconclusive. We examined pre- and postdiagnosis use of supplements in postmenopausal breast cancer survivors in Germany and investigated associations between postdiagnosis use of antioxidants and other supplements, and prognosis (total and breast cancer mortality, and recurrence-free survival) both overall and in women who received chemotherapy and radiation therapy. Data from 2223 postmenopausal women diagnosed with nonmetastatic breast cancer from the population-based Mamma Carcinoma Risk Factor Investigation (MARIE) study were used. Women were interviewed at recruitment in 2002-2005 and again in 2009 and followed-up until 30 June 2015. Multivariate Cox regression analysis was used to estimate HRs and corresponding 95% CIs. Pre- and postdiagnosis supplement use was reported by 36% and 45% of the women, respectively. There were 240 deaths (134 from breast cancer) and 200 breast cancer recurrences after a median follow-up time of 6.0 y after the 2009 re-interview. After adjusting for relevant confounders, concurrent antioxidant use with chemotherapy or radiation therapy among 1940 women was associated with increased risk of total mortality (HR: 1.64; 95% CI: 1.01, 2.66) and worsened recurrence-free survival (HR: 1.84; 95% CI: 1.26, 2.68). Overall postdiagnosis supplement use was not associated with breast cancer prognosis. Antioxidant use during chemotherapy or radiation therapy was associated with worsened breast cancer prognosis in postmenopausal women. There was no overall association between postdiagnosis supplement use and breast cancer prognosis. Results from our study align with the current recommendation to possibly avoid the use of antioxidants during chemotherapy or radiation therapy.

13 April 2021 in Cancers
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Journal Article
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TMTabea Maurer
Tabea Maurer
KTKathrin Thöne
Kathrin Thöne
NONadia Obi
Nadia Obi
AJAudrey Y. Jung
Audrey Y. Jung
SBSabine Behrens
Sabine Behrens
JCJenny Chang-Claude
Jenny Chang-Claude
Background: Breast cancer (BC) survivors often suffer from late and long-term residual symptoms of the disease and its treatment. To date, long-term health-related quality of life (HRQoL) in breast cancer survivors has been seldom investigated and rarely compared to unaffected women (controls). Aim: This study aimed to investigate HRQoL over time using patient-reported status before diagnosis, during treatment, 1 year post-surgery, approx. 5 years and ≥10 years post-diagnosis. We also compared survivors’ HRQoL with controls’ still alive 10 years after recruitment. Methods: Data from the German population-based Mamma Carcinoma Risk Factor Investigation (MARIE) cohort of 1123 BC patients aged 50–74 years at diagnosis (2002–2005) and of 3453 matched controls were used for analysis. HRQoL was assessed with the European Organization for Research and Treatment of Cancer (EORTC QLQ-C30) questionnaire. All analyses were conducted for all ages as well as stratified according to three age groups (≤58 years, 59–64 years, ≥64 years). Differences in survivors’ general HRQoL before, during, and after therapy were investigated using a t-test/Wilcoxon signed-rank test. Changes in the HRQoL of survivors stratified by age from FU1 to FU2 were assessed via repeated analysis of variance. The HRQoL of survivors compared to the controls at FU2 was analyzed using an analysis of variance. Results: Over all ages, the general HRQoL in patients improved in the first 5 years post-diagnosis. In the subsequent years, HRQoL slightly deteriorated but was comparable to that of the controls. Younger survivors mostly improved their HRQoL from the 5 to 10-year follow-up but remained negatively affected for most functioning and symptom scales compared to controls. In older survivors, HRQoL hardly changed over time and detriments were less pronounced compared to controls, except for insomnia. Conclusions: Restrictions of HRQoL persist for more than 10 years and are most prominent among younger survivors. Researchers and clinicians should be aware of such potential deteriorations and age-dependent differences in order to optimize/adapt long-term cancer survivor care.

6 June 2017 in Arthritis Research & Therapy
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Journal Article
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MAManas Akmatov
Manas Akmatov
NRNadja Röber
Nadja Röber
WAWolfgang Ahrens
Wolfgang Ahrens
DFDieter Flesch-Janys
Dieter Flesch-Janys
JFJulia Fricke
Julia Fricke
Frank PesslerFrank Pessler
Frank Pessler
We determined the prevalence of anti-nuclear autoantibodies (ANAs) in the German adult population and examined the association between ANAs and cardiovascular and metabolic disorders. We used data and blood samples from the pretest phases of the German National Cohort, obtained from six of the 18 study centers (n = 1199). All centers applied standardized instruments including face-to-face interviews, anthropometric measurements and collection of blood samples. Self-reported histories of diabetes mellitus, heart attack and elevated blood cholesterol and/or lipids were recorded. Height, weight and blood pressure were measured. ANAs were detected using a semi-automated system (AKLIDES®; Medipan GmbH, Dahlewitz, Germany). A positive ANA was defined as a titer ≥ 1:80. ANA were classified as weakly (1:80 or 1:160), moderately (1:320 or 1:640) or strongly (≥1:1280) positive. Specific autoantibodies against nuclear antigens were detected with second-step assays according to the ANA staining pattern. Associations between the assessed disorders and ANA positivity and pattern were examined using sex and age-adjusted mixed-effects logistic regression models. Thirty-three percent (95% confidence interval; 31–36%) of the 1196 participants (measurements could not be obtained from three samples) were ANA positive (titer ≥ 1:80). The proportions of weakly, moderately and strongly positive ANA were 29%, 3.3% and 1.3%, respectively. ANA positivity was more common among women than men across all titers (χ2, p = 0.03). ANA positivity, even when stratified according to height of titer or immunofluorescent pattern, was not associated with diabetes, elevated blood cholesterol and/or lipids, obesity or hypertension. Second-step autoantibody assays were positive in 41 of the 83 samples (49%) tested, with anti-DFS70 (n = 13) and anti-dsDNA (n = 7) being most frequent. These subgroups were too small to test for associations with the disorders assessed. The prevalence of ANA positivity in the German general population was similar to values reported from other countries. Contrary to other studies, there was no association with selected self-reported and objectively measured cardiovascular and metabolic variables.

22 April 2025 in European Journal of Epidemiology
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Journal Article
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SRStefan Rach
Stefan Rach
MSMatthias Sand
Matthias Sand
ARAchim Reineke
Achim Reineke
Heiko BecherHeiko Becher
Heiko Becher
KGKarin Halina Greiser
Karin Halina Greiser
KGKathrin Günther
Kathrin Günther
The German National Cohort (NAKO) is the largest population-based epidemiologic cohort study in Germany and investigates the causes of the most common chronic diseases. Between 2014 and 2019, a total of 1.3 million residents aged 20–69 years from 16 German regions were randomly selected from the general population and invited to participate following a highly standardized recruitment protocol. The overall response was 15.6% and differed considerably across study centers (7.6–30.7%). Females were more likely to participate than males (17.5% vs. 14.1%) and participation increased with age (10.2% in age group “ < 29 years” up to 20.7% in age group “ > 60 years”). Across all study regions, response was highest in rural areas (22.3%), followed by towns and suburbs (17.2%), and was lowest in cities (14.5%). Compared with the general population in the respective study regions, participants with low and medium education are underrepresented in the NAKO sample, while highly educated participants are overrepresented. Participants with non-German nationality and with a migration background are also underrepresented. Participants living in single households are underrepresented, while participants from larger households (2 or more persons) are overrepresented compared to the general population. Survey weights are made available to researchers along with the study data that account for the sampling design and adjust for differences in the distribution of age, sex, nationality (German vs. non-German), migration status, education, and household size.

1 August 2009 in Cancer Epidemiology, Biomarkers & Prevention
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Journal Article
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NONadia Obi
Nadia Obi
JCJenny Chang-Claude
Jenny Chang-Claude
JBJürgen Berger
Jürgen Berger
WBWilhelm Braendle
Wilhelm Braendle
TSTracy Slanger
Tracy Slanger
DFDieter Flesch-Janys
Dieter Flesch-Janys
Background:The use of herbal preparations (HEP) to alleviate climacteric disorders is expected to increase as women seek alternatives to menopausal hormone therapy to avoid the associated breast cancer risk. Data are sparse on the long-term effects of HEP containing phytoestrogens and black cohosh on breast cancer risk.Methods: Within a German case-control study, associations between patterns of HEP use and incident breast cancer were investigated in 10,121 postmenopausal women (3,464 cases, 6,657 controls). Information on HEP use was collected in face-to-face interviews supported by a list of brand names. Multivariate logistic and polytomous regression analyses were done.Findings: Ever use of HEP (9.9%) was inversely associated with invasive breast cancer [odds ratio (OR), 0.74; 95% confidence interval (CI), 0.63-0.87] in a dose-dependent manner (OR, 0.96 per year of use; P = 0.03). Classes of HEP did not differ significantly (Pheterogeneity = 0.81). Risks for invasive ductal (OR, 0.72; 95% CI, 0.60-0.87) and combined lobular/mixed/tubular tumors (OR, 0.76; 95% CI, 0.58-1.01) were similarly reduced by any HEP use but not for in situ carcinomas (1.34; 95% CI, 0.86-2.09). There were no substantial differences in associations of HEP use by estrogen receptor status (ER+ OR, 0.74; 95% CI, 0.62-0.89; ER− OR, 0.68, 95% CI, 0.50-0.93) and progesterone receptor status of the tumor.Interpretation: Our findings support the hypothesis that HEP use protects from invasive breast cancer in postmenopausal women. Among conceivable modes of action, those independent of estrogen receptor–mediated pathways seem to be involved (i.e., cytotoxicity, apoptosis). (Cancer Epidemiol Biomarkers Prev 2009;18(8):2207–13)

1 February 2011 in International Journal of Women's Health
Verified
Journal Article
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NONadia Obi
Nadia Obi
AVAlina Vrieling
Alina Vrieling
JHJudith Heinz
Judith Heinz
CCChang- Claude
Chang- Claude
Experimental studies have shown that two main estrogen metabolites hydroxylated by CYP1A1 and CYP1B1 in the breast differentially affect breast cell proliferation and carcinogenesis. Although 16α -hydroxyestrone (16α OHE1) exerts estrogenic activity through covalent estrogen receptor (ER) binding, 2-hydroxyestrone (2OHE1) presumably has antiestrogenic capabilities. The ratio of 2OHE1 to 16α OHE1 represents the relative dominance of one pathway over the other and is believed to be modifiable by diet. It was hypothesized that women with or at high risk of breast cancer have a lower estrogen metabolite ratio (EMR) compared with women without breast cancer. We conducted a systematic review on the EMR as a predictor for breast cancer. A total of nine studies (six prospective and three retrospective) matched our inclusion criteria, comprising 682 premenopausal cases (1027 controls) and 1189 postmenopausal cases (1888 controls). For the highest compared with the lowest quantile of urinary EMR, nonsignificant associations suggested at best a weak protective effect in premenopausal but not in postmenopausal breast cancer (range of odds ratios: 0.50–0.75 for premenopausal and 0.71–1.31 for postmenopausal). Circulating serum/plasma EMR was not associated with breast cancer risk. Associations were inconclusive for receptor subtypes of breast cancer. Uncontrolled factors known to be involved in breast carcinogenesis, such as 4-hydroxyestrone (4OHE1) concentration, may have confounded results for EMR. Results of the prospective studies do not support the hypothesis that EMR can be used as a predictive marker for breast cancer risk. Future research should concentrate on profiles of estrogen metabolites, including 4OHE1, to gain a more complete picture of the relative importance of single metabolites for breast cancer.