title: The 2003 heat wave in France: hydratation status changes in older inpatients.
abstract: Little is known about the impact of behavioral changes after the 2003 heat wave on hydration status of elderly citizens in France. We used an administrative data file provided information about 23,022 inpatients aged > or =70 years admitted between 2000 and 2006, including vital status at discharge and Charlson comorbidity index and matched it with the result of five blood tests (sodium, potassium, glucose, urea nitrogen, creatinine) within the first 24 h after admission and with daily temperatures before admission. We then measured the prevalence of plasma tonicity (PT) <275 mOsm/l or >300 mOsm/l, blood urea nitrogen/creatinine ratio (BUNC) >100 and inhospital mortality. In 2000-2002, 2003, 2004-2006, prevalence (%) was, respectively 7.5, 8.0, 9.5 (P < 0.0001) for PT < 275 mMol/l, 8.4, 10.4, 7.2 (P < 0.0001) for PT > 300 mOsm/l, and 35.4, 30.7, 26.7 (P < 0.0001) for BUNC > 100. Inhospital mortality rate was 10.8, 10.8 and 9.0%, respectively (P < 0.0001). After adjustment for covariates, OR (95% CI) in 2004-2006 with reference to 2000-2002 was 1.26 (1.13-1.39) for PT < 275 mMol/l, 0.85 (0.76-0.94) for PT > 300 mOsm/l, and 0.65 (0.61-0.69) for BUNC > 100. Inhospital mortality risk associated with hydration disorders did not vary significantly over periods for PT < 275 mMol/l (HR 1.06 to 1.40) and PT > 300 mOsm/l (HR 1.76 to 1.96) but was lower for BUNC > 100 in 2003 (HR 1.27) than in 2000-2002 (HR 1.64) or 2004-2006 (HR 1.77) (P = 0.04). So, since the 2003 heat wave, significant shifts in prevalence of intracellular hydration disorders indicate behavioral changes with positive impact on hydration status.
authors.affiliation: Department of Internal Medicine, Hôpital Saint-Antoine, Assistance Publique/Hôpitaux de Paris, 184 rue du Fbg Saint Antoine, 75571, Paris cedex 12, France.
authors.forename: Adrien
authors.initials: A
authors.lastname: Kettaneh
authors.forename: Laurence
authors.initials: L
authors.lastname: Fardet
authors.forename: Nathalie
authors.initials: N
authors.lastname: Mario
authors.forename: Aurelia
authors.initials: A
authors.lastname: Retbi
authors.forename: Namik
authors.initials: N
authors.lastname: Taright
authors.forename: Kiet
authors.initials: K
authors.lastname: Tiev
authors.forename: Ingrid
authors.initials: I
authors.lastname: Reinhard
authors.forename: Bertrand
authors.initials: B
authors.lastname: Guidet
authors.forename: Jean
authors.initials: J
authors.lastname: Cabane
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001806:Blood Urea Nitrogen; D003404:Creatinine / Q000097:blood; D003681:Dehydration / Q000097:blood / Q000209:etiology / Q000401:mortality*; D004190:Disasters / Q000706:statistics & numerical data*; D005260:Female; D005602:France / Q000453:epidemiology; D018883:Heat Stroke / Q000209:etiology / Q000401:mortality*; D017052:Hospital Mortality; D006358:Hot Temperature / Q000009:adverse effects*; D006801:Humans; D015994:Incidence; D008297:Male; D009994:Osmolar Concentration; D015995:Prevalence
chemical_list: D003404:Creatinine