[Prevalence and associated factors of underweight among the elderly in Qionglai City].

Objective: To examine the prevalence and associated factors of underweight among the elderly in Qionglai City.

Methods: A total of 14 929 residents aged ≥60 years recruited through multistage stratified cluster random sampling in 24 towns or streets of Qionglai City were surveyed from August to October 2018, including 7581 males and 7348 females; 8121 aged 60-69, 5176 aged 70-79, and 1632 aged ≥ 80. Questionnaires and physical examinations were conducted to collect the characteristics, behaviors, healthy history of the subjects, height, and weight, etc. The judgment of underweight was based on the criteria of weight for adults(WS/T 428-2013). The prevalence of underweight was calculated and its determinants were analyzed with a non-conditional logistic regression model.

Results: The prevalence of underweight among the elderly was 5. 7%(851/14929), 5. 4% for male(413/7581) and 6. 0% for female(438/7348). The result of logistic regression analysis revealed that female(OR=1. 365, 95%CI 1. 147-1. 624), aged elderly ≥ 70 years(70-79 years: OR=1. 652, 95%CI 1. 402-1. 948; ≥80 years: OR=2. 557, 95%CI 2. 079-3. 145), no spouse(OR=1. 196, 95%CI 1. 008-1. 420), former and current smokers(current smokers: OR=1. 247, 95%CI 1. 018-1. 528; former smokers: OR=1. 536, 95%CI 1. 036-2. 276), daily physical activities less than 6000 steps(OR=1. 259, 95%CI 1. 083-1. 462), those who didn't receive medical diagnosis of hypertension(OR=1. 591, 95%CI 1. 321-1. 915) presented a high prevalence of being underweight.

Conclusion: The prevalence of underweight is at a low level among the elderly in Qionglai City. Gender, age, marital status, smoking, daily physical activities, hypertension were associated with being underweight.