Red Meat, Increased Iron Load and CVD Risk

The present study part of the the European Prospective Investigation into Cancer and Nutrition (EPIC) - Heidelberg, a large-scale observational cohort study located at the German Cancer Research Center, Heidelberg, Germany. The study started between 1994 and 1998, when 25 540 adults from the local general population were recruited. Study participants are being followed-up by active and passive procedures. The main aim of the study is to evaluate associations between diet, lifestyle as well as metabolism and risks of major chronic diseases (cancer, cardiovascular diseases, diabetes).

Here, the investigators register a project from within EPIC-Heidelberg on prediagnostic iron status as a potential mediator of associations between pre-diagnostic red meat consumption and cardiovascular disease risk. For this particular project, an embedded case-cohort set-up was chosen, i.e. iron status markers (primary marker: serum ferritin; secondary markers: serum transferrin, serum iron) were measured in baseline blood samples from a random subcohort (n=2738) and all validated incident cases of myocardial infarction (n=556), stroke (n=513), and CVD death (n=327) that occured until the closure date of the present study (12-31-2009).

Statistical analyses follow four steps to assess whether iron status may mediate associations between red meat consumption and CVD risk, as proposed by Wittenbecher et al. (Am J Clin Nutr, 2015: www.ncbi.nlm.nih.gov/pubmed/25948672):

• Multivariable Cox regression analyses on red meat consumption and CVD risk, assuming a significant positive association
• Multivariable linear regression analyses on red meat consumption and iron status, assuming a significant positive association
• Multivariable Cox regression analyses on iron status and CVD risk, assuming a significant positive association
• Multivariable Cox regression analyses on red meat consumption and CVD risk, additionally adjusting for iron status, assuming that the association will be attenuated by adjustment for iron status

Inclusion criteria

General population, age 35-65 years

Exclusion criteria

Prevalent myocardial infraction or stroke