title: Hemodynamics and metabolism at low versus moderate altitudes.
abstract: Despite the higher prevalence of diabetes and hypertension in populations residing at moderate altitudes, mortality in these populations is lower than in populations residing at low altitudes. To examine whether metabolic and hemodynamic differences can explain this apparent paradox, we performed a cross-sectional study of a general population sample recruited in the Canary Islands, Spain (n=6729). We recorded altitude of residence, age, heart rate, blood pressure, body mass index, social class, physical activity, energy intake, alcohol intake, smoking habit, prevalence of type 2 diabetes mellitus and hypertension. In a subsample (n=903), we recorded serum concentration of cholesterol, triglycerides, glucose, C peptide, leptin, soluble leptin receptor (sObR), C-reactive protein, resistin, soluble CD40 ligand (sCD40L), and paraoxonase activity (PON), and we estimated insulin resistance and free leptin index. We found an inverse association between altitude and heart rate (p<0.001), leptin (p<0.001), free leptin index (p<0.001), resistin (p<0.001), and sCD40L (p<0.05) and a direct association between altitude and hypertension (odds ratio=1.29 for altitude >600 m; 95% confidence interval=1.03-1.62), glycemia (p<0.05), C peptide (p<0.001), insulin resistance (p<0.001), sObR (p<0.05), and PON (p<0.05). When social class was included in the multivariate model, the association with PON was no longer significant. In conclusion, individuals residing at moderate altitudes have a lower heart rate and lower serum concentration of total leptin, free leptin, and sCD40L. These differences may partially explain the lower mortality in these populations.
authors: Unidad de Investigación del Hospital Universitario, Nuestra Señora de Candelaria y de Atención Primaria, Tenerife, Spain. acableo@gobiernodecanarias.org
authors: Antonio Cabrera
authors: AC
authors: de León
authors: María del Cristo Rodríguez
authors: Mdel C
authors: Pérez
authors: Delia Almeida
authors: DA
authors: González
authors: Buenaventura Brito
authors: BB
authors: Díaz
authors: Santiago Domínguez
authors: SD
authors: Coello
authors: Ana González
authors: AG
authors: Hernández
authors: Armando
authors: A
authors: Aguirre-Jaime
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000531:Altitude; D001794:Blood Pressure; D023201:CD40 Ligand / Q000097:blood*; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000453:epidemiology; D004734:Energy Metabolism; D005260:Female; D006339:Heart Rate; D006439:Hemodynamics; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000453:epidemiology; D007249:Inflammation / Q000097:blood; D007333:Insulin Resistance; D020738:Leptin / Q000097:blood*; D050356:Lipid Metabolism; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D020738:Leptin; D023201:CD40 Ligand