Nutritional status and mortality in the elderly: The obesity paradox

Introduction The “obesity paradox” is poorly understood in vulnerable elderly hospitalised populations. Thus, we aimed to analyse the impact of body mass index (BMI) on early (6 week), one- and two-year mortality. Design Prospective multicentre cohort study with a two-year follow-up of elderly patients. Settings Nine university hospitals in France. Participants Patients aged 75+, hospitalised in medical wards through the emergency department. Measurement Inpatients’ characteristics were obtained through a comprehensive geriatric assessment, conducted in the first week of hospitalisation. All-cause mortality at 6 week, one and two years were studied using multivariable Cox modelling. Results The cohort included 1306 patients, aged 85 ± 6years, with a majority of women (65%). By multivariable analyses, when adjusted for age, walking disorders, dementia syndrome, dependency, and comorbidities, one and two-year all-cause mortality were inversely associated with a levels of BMI. Association between early (6-week) mortality and BMI values did not reach significance. Conclusion While our findings seem to confirm the reality of the “obesity paradox” in vulnerable older hospitalized population, the exact understanding of underlying mechanisms and even the truthfulness of this paradoxical relationship are still fraught with considerable methodological, epidemiological and metabolic challenges.