Renee Stark

Dr. Renee Stark

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Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

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

Representative Publications

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22 February 2018 in Nutrients
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Journal Article
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CBCharlotte Bamberger
Charlotte Bamberger
ARAndreas Rossmeier
Andreas Rossmeier
KLKatharina Lechner
Katharina Lechner
LWLiya Wu
Liya Wu
EWElisa Waldmann
Elisa Waldmann
KPKlaus G. Parhofer
Klaus G. Parhofer
Regular walnut consumption is associated with better health. We have previously shown that eight weeks of walnut consumption (43 g/day) significantly improves lipids in healthy subjects. In the same study, gut microbiome was evaluated. We included 194 healthy subjects (134 females, 63 ± 7 years, BMI 25.1 ± 4.0 kg/m2) in a randomized, controlled, prospective, cross-over study. Following a nut-free run-in period, subjects were randomized to two diet phases (eight weeks each); 96 subjects first followed a walnut-enriched diet (43 g/day) and then switched to a nut-free diet, while 98 subjects followed the diets in reverse order. While consuming the walnut-enriched diet, subjects were advised to either reduce fat or carbohydrates or both to account for the additional calories. Fecal samples were collected from 135 subjects at the end of the walnut-diet and the control-diet period for microbiome analyses. The 16S rRNA gene sequencing data was clustered with a 97% similarity into Operational Taxonomic Units (OTUs). UniFrac distances were used to determine diversity between groups. Differential abundance was evaluated using the Kruskal–Wallis rank sum test. All analyses were performed using Rhea. Generalized UniFrac distance shows that walnut consumption significantly affects microbiome composition and diversity. Multidimensional scaling (metric and non-metric) indicates dissimilarities of approximately 5% between walnut and control (p = 0.02). The abundance of Ruminococcaceae and Bifidobacteria increased significantly (p < 0.02) while Clostridium sp. cluster XIVa species (Blautia; Anaerostipes) decreased significantly (p < 0.05) during walnut consumption. The effect of walnut consumption on the microbiome only marginally depended on whether subjects replaced fat, carbohydrates or both while on walnuts. Daily intake of 43 g walnuts over eight weeks significantly affects the gut microbiome by enhancing probiotic- and butyric acid-producing species in healthy individuals. Further evaluation is required to establish whether these changes are preserved during longer walnut consumption and how these are linked to the observed changes in lipid metabolism.

1 January 2010 in Inflammatory Bowel Diseases
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Journal Article
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RSRenee Stark
Renee Stark
PRPeter Reitmeir
Peter Reitmeir
RLReiner Leidl
Reiner Leidl
HKHans-Helmut König
Hans-Helmut König

6 October 2017 in Nutrients
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Journal Article
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CBCharlotte Bamberger
Charlotte Bamberger
ARAndreas Rossmeier
Andreas Rossmeier
KLKatharina Lechner
Katharina Lechner
LWLiya Wu
Liya Wu
EWElisa Waldmann
Elisa Waldmann
KPKlaus G. Parhofer
Klaus G. Parhofer
Studies indicate a positive association between walnut intake and improvements in plasma lipids. We evaluated the effect of an isocaloric replacement of macronutrients with walnuts and the time point of consumption on plasma lipids. We included 194 healthy subjects (134 females, age 63 ± 7 years, BMI 25.1 ± 4.0 kg/m2) in a randomized, controlled, prospective, cross-over study. Following a nut-free run-in period, subjects were randomized to two diet phases (8 weeks each). Ninety-six subjects first followed a walnut-enriched diet (43 g walnuts/day) and then switched to a nut-free diet. Ninety-eight subjects followed the diets in reverse order. Subjects were also randomized to either reduce carbohydrates (n = 62), fat (n = 65), or both (n = 67) during the walnut diet, and instructed to consume walnuts either as a meal or as a snack. The walnut diet resulted in a significant reduction in fasting cholesterol (walnut vs. control: −8.5 ± 37.2 vs. −1.1 ± 35.4 mg/dL; p = 0.002), non-HDL cholesterol (−10.3 ± 35.5 vs. −1.4 ± 33.1 mg/dL; p ≤ 0.001), LDL-cholesterol (−7.4 ± 32.4 vs. −1.7 ± 29.7 mg/dL; p = 0.029), triglycerides (−5.0 ± 47.5 vs. 3.7 ± 48.5 mg/dL; p = 0.015) and apoB (−6.7 ± 22.4 vs. −0.5 ± 37.7; p ≤ 0.001), while HDL-cholesterol and lipoprotein (a) did not change significantly. Neither macronutrient replacement nor time point of consumption significantly affected the effect of walnuts on lipids. Thus, 43 g walnuts/d improved the lipid profile independent of the recommended macronutrient replacement and the time point of consumption.

13 January 2011 in BMC Health Services Research
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Journal Article
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RSRenee Stark
Renee Stark
JJJürgen John
Jürgen John
RLReiner Leidl
Reiner Leidl
This study's aim was to develop a first quantification of the frequency and costs of adverse drug events (ADEs) originating in ambulatory medical practice in Germany.

6 May 2011 in Diabetes/Metabolism Research and Reviews
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RSRenee Stark
Renee Stark
MSMichaela V. Schunk
Michaela V. Schunk
CMChrista Meisinger
Christa Meisinger
WRWolfgang Rathmann
Wolfgang Rathmann
RLReiner Leidl
Reiner Leidl
FGfor the KORA Study Group
for the KORA Study Group

17 September 2015 in Diabetology & Metabolic Syndrome
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Journal Article
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MLMichael Laxy
Michael Laxy
RSRenee Stark
Renee Stark
CMChrista Meisinger
Christa Meisinger
IKInge Kirchberger
Inge Kirchberger
MHMargit Heier
Margit Heier
RHRolf Holle
Rolf Holle
Although the population-based German disease management programs (DMPs) for diabetes mellitus (DM) and coronary heart disease (CHD) are among the biggest worldwide, evidence on the effectiveness of these programs is still inconclusive or missing, particularly for high risk patients with comorbidities. The objective of this study was therefore to analyze the impact of DMPs on process and outcome parameters in patients with both, type 2 DM and CHD. Analyses are based on two postal surveys of patients from the KORA myocardial infarction registry (southern Germany) with type 2 DM and on two postal validation studies with patients’ general physicians (2006, n = 312 and 2011, n = 212). The association between DMP enrollment (being enrolled in either DMP-DM or DMP-CHD) and guideline care (defined by several process indicators) at baseline (2006) and its development until follow-up (2011) was analyzed using logistic regression models accounting for the repeated measurements structure. The impact of DMP enrollment/guideline care on cumulated (quality-adjusted) life years ((QA)LYs) over a 4-year time horizon (2006–2010) was assessed using multiple linear regression methods. Logistic regression models were applied to analyze the association between DMP status and patient self-management at follow-up. Being enrolled in a DMP was associated with better guideline care at baseline [OR = 2.3 (95 % CI 1.27–4.03)], but not at follow-up [OR = 0.80 (95 % CI 0.40–1.58); p value for time-interaction <0.01]. DMP enrollment was not significantly [+0.15 LYs (95 % CI –0.07, 0.37); +0.06 QALYs (95 % CI –0.15, 0.26)], but treatment according to guideline care significantly [+0.40 LYs (95 % CI 0.21–0.60); +0.28 QALYs (95 % CI 0.10–0.45)] associated with higher (quality-adjusted) survival over the 4-year follow-up period. DMP enrollees further reported a somewhat better self-management than patients not being enrolled into a DMP. The results of this study concerning the effectiveness of DMPs in patients with DM and CHD are mixed, but are weakly in favor of DMPs. However, we found a clear positive impact of guideline care on quality adjusted survival in this patient group. The development of the association between DMP enrollment and guideline care over the follow-up time indicates some external effects, which should be the subject of further investigations.