title: Inverse association between altitude and obesity: A prevalence study among andean and low-altitude adult individuals of Peru.
abstract: OBJECTIVE
  To determine the association between altitude and obesity in a nationally representative sample of the Peruvian adult population.
  
  
  METHODS
  This is a cross-sectional analysis of publicly available data from the Food and Nutrition National Center (CENAN, Peru), period 2009-2010. The Prevalence ratio of obesity and abdominal obesity was determined as a measure of association. Obesity and abdominal obesity were diagnosed based on direct anthropometric measurements.
  
  
  RESULTS
  The final data set consisted of 31,549 individuals ≥20 years old. The prevalence ratio of obesity was as follows: 1.00 between 0 and 499 m (reference category), 1.00 (95% confidence interval 0.87-1.16) between 500-1,499 m, 0.74 (0.63-0.86) between 1,500-2,999 m, and 0.54 (0.45-0.64) at ≥3,000 m, adjusting for age, sex, self-reported physical activity, out-migration rate, urbanization, poverty, education, and geographical latitude and longitude. In the same order, the adjusted prevalence ratio of abdominal obesity was 1.00, 1.01 (0.94-1.07), 0.93 (0.87-0.99), and 0.89 (0.82-0.95), respectively. We found an interaction between altitude and sex and between altitude and age (P < 0.001, for both interactions) on the association with obesity and abdominal obesity.
  
  
  CONCLUSIONS
  Among Peruvian adult individuals, we found an inverse association between altitude and obesity, adjusting for multiple covariates. This adjusted association varied by sex and age.
authors.affiliation: Diabetes and Obesity Research Institute, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA.
authors.forename: Orison O
authors.initials: OO
authors.lastname: Woolcott
authors.affiliation: Instituto de Medicina Tropical Daniel A. Carrión, Department of Preventive Medicine and Public Health, Universidad Nacional Mayor de San Marcos, Lima, Peru.|Department of Preventive Medicine and Public Health, Faculty of Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru.
authors.forename: Cesar
authors.initials: C
authors.lastname: Gutierrez
authors.affiliation: Instituto Nacional de Biología Andina, Universidad Nacional Mayor de San Marcos, Lima, Peru.
authors.forename: Oscar A
authors.initials: OA
authors.lastname: Castillo
authors.affiliation: Department of Biomathematics, University of California, Los Angeles (UCLA), California, USA.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Elashoff
authors.affiliation: Diabetes and Obesity Research Institute, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA.
authors.forename: Darko
authors.initials: D
authors.lastname: Stefanovski
authors.affiliation: Diabetes and Obesity Research Institute, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA.
authors.forename: Richard N
authors.initials: RN
authors.lastname: Bergman
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000531:Altitude; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology* / Q000209:etiology; D056128:Obesity, Abdominal / Q000453:epidemiology* / Q000209:etiology; D010568:Peru / Q000453:epidemiology; D015995:Prevalence; D012737:Sex Factors; D055815:Young Adult