Johanne Tremblay

Radio-Telemetry in Biomedical Research - Radio-Telemetry Blood Pressure Measurements in Animal Models of Hypertension, How It Revolutionized Hypertension Research

Radiotelemetry is employed in several fields to circumvent several issues: areas difficult or dangerous to access, monitoring of dangerous processes, need for secret monitoring. In biological sciences, telemetry is mainly useful because it decreases the observer bias and interference. In the field of medicine, the current research is mostly aimed at findings the cause and appropriate cures to common diseases. Common diseases are widely prevalent diseases for which we know only partially the causes and for which, as a consequence, we only propose treatments to alleviate the symptoms or their impacts on target organs. The common examples of such diseases to name a few are: diabetes, cancer(s), obesity, multiple sclerosis and hypertension, not to mention most of the psychiatric illnesses. They are characterized by a strong genetic component and a strong environmental influence since their prevalence is markedly influenced by age, diet, exercise or other environmental stressors. This important environmental modulation makes them more difficult to study. Therefore, our goal here will be to illustrate the challenge of studying environmentmodulated traits. With hypertension as an example, we will describe the use and benefits of employing radiotelemetry in hypertension research in order to be able to subtract the role of the environment or, conversely to quantify its impact on blood pressure. In the current postgenome era, with enough financial support and colleagues from around the world, it has never been easier to design and perform huge genome-wide association studies to try to unveil the genetic determinants of common diseases. Each month, hundreds of loci are reported that are associated with a higher prevalence of diseases and single nucleotide polymorphisms covering the entire genome are proposed to be in linkage with disease genes. We also know that very few of these proposed loci end up being truly associated with diseases in replication studies and we will present the current arguments pro and against this approach in the field of hypertension. This, we hope, will illustrate the point that we want to make in this chapter: in order to perform valid genome-wide association studies in human or genetic studies in animal models to uncover the genetic determinants of common diseases, it is essential to clearly define the studied phenotype(s) and to ensure that their measurements are performed accurately with the least amount of confounders or artefacts.