Of the 2,100 participants, 1,239 (59%) were female and 861 (41%) were male (Table  1); their mean age was 36.4 ± 12.8 years. Males aged 18–34 years were under-represented in comparison with the national population of Nepal, according to census data (Table  1). Almost one quarter (491; 23.4%) of participants lived above 2,000 m.