CV Science

nathalie salles MD PhD Internal Medicine and geriatrics

Course and current status

1.  Hospital Titles

1992: Intern in Hospitals of Bordeaux

1996: Clinical Instructor and Hospital consultant (Univ. Hosp. Bordeaux, France)

2000: Clinical Instructor and Hospital consultant (Univ. Hosp. Geneva, Switzerland)

2002: Hospital Practionner (Univ. Hosp. Bordeaux, France)

2006: Assistant Professor (Univ. Hosp. Bordeaux, France)

2008: University professor – Hospital Practitioner (Univ. Hosp. Bordeaux, France)

2.   University Titles

1996: Graduated Doctor of Medicine (University Victor Segalen, Bordeaux)

1996: Graduated in Gastroenterology Specialty (University Victor Segalen, Bordeaux)

1999: Graduated in Geriatrics (University Victor Segalen, Bordeaux)

1999: Master degree (Science) (University Victor Segalen, Bordeaux)

2002: Master Class European Academy for Medicine of Ageing (EAMA), Sion, Switzerland

2005: Thesis for Dr. of Science degree (PhD) (University Victor Segalen, Bordeaux)

2007: Authorization to direct research (INSERM 853, University Victor Segalen, Bx) 

2008: University professor, Hospital Practitioner, Internal Medicine and Geriatrics 

Scientific summary

H. pylori and ageing people 

Our initial work showed a lower prevalence of H. pylori infection (47.7%) than expected in this ageing population which can be explained on one hand by the higher polymedication with repetitive antibiotherapies and on the other hand by more frequent gastric atrophic lesions which offers a less favorable ground for H. pylori. We showed that the carbon 13 labelled urea breath test had the best performance compared to other diagnostic tests for the infection in this population (Salles-Montaudon et al., JAGS, 2002; Salles N, Expert Rev Anti Infect Ther. 2007).
These past years our activity has been directed in 4 directions 

1. Role of H. pylori in gastric ageing

Different hypotheses have been proposed concerning the mechanisms of H. pylori infection in gastric ageing, including the radical theory. Chronic secondary inflammation due to an H. pylori infection induces an oxidative stress by the activation of phagocytotic enzymes (NADPH oxidases). The aim of the study was therefore to identify the expression of certain NADPH oxidase homologs, Nox1, Nox2, and Nox5, in the stomach of elderly hospitalized patients. This study allowed us to show for the first time that the gastric mucosa of aged people does not express Nox1 but expresses other enzymes of the Nox family, including Nox2 and Nox5, the expression of Nox2 being significantly associated with the severity of inflammatory and atrophic gastric lesions (Salles N, Exp Gerontol 2005; Salles N, Dig Dis 2007; Salles N, Best Pract Res Clin Gastroenterol. 2009) 

2. Role of gastric ageing in the regulation of appetite

The stomach plays a central role in the regulation of appetite by the emission of motor or hormone satiety signals, such as leptin and ghrelin. Our objective was to determine the variations of gastric and plasmatic expression of appetite peptides (leptin and ghrelin) in aged individuals according to their H. pylori status. The results showed that the expression of leptin and ghrelin peptides decreased both in the presence of an H. pylori infection and in the presence of atrophic gastritis lesions. The results also showed that an H. pylori infection was negatively correlated to the caloric ratio and the body mass index of these aged patients. The decrease in plasmatic and gastric levels of the strong orexigen, ghrelin, could explain the lack of appetite and the malnutrition of aged people who have chronic gastritis lesions due to H. pylori (Salles N, J Gerontol A Biol Sci Med Sci 2006).

 3. The impact of an H. pylori infection on mortality (PAQUID Cohort)

The aim of this study was to evaluate the impact of an H. pylori infection on the mortality rate in a population of subjects older than 65 years. The follow-up of 605 subjects over 15 years (data of the PAQUID Cohort), after adjustment for age, gender, and cardiovascular comorbidity, showed that an H. pylori infection is not a risk factor for mortality (HR=1.2, 95% CI [0.94; 1.52]) (Salles N, JAGS 2010).

 4. H. pylori infection and Alzheimer's disease

The risk factors identified for dementia are often inaccessible to intervention (age, gender, genetic). New hypotheses have recently been suggested, such as the possible relationship between H. pylori infection and dementia via inflammatory mechanisms, both pro-oxidant and carential. Based on the data from the PAQUID Cohort study, we showed an association between H. pylori and dementia after adjustment for age and gender (HR=1.7, 95% CI [1.1-2.7]). An article has been submitted for publication.