BACKGROUND: There was no consistent recognition of the association between high or low body mass index (BMI) and @entity283 ( @entity283 ). The aim of this research was to study the association between BMI and @entity283 in Chinese adults, and to further explore the stability of that association in the subgroup analysis stratified by status of chronic conditions. METHODS: A total of 21,218 adults aged 18 and older were classified as underweight, normal weight, overweight, class I @entity28 , and class II @entity28 based on their BMI. @entity283 was measured by the SF-36 Health Survey. The independent impact of each BMI category on @entity283 was examined through standard least squares regression by comparing the difference of SF-36 scores and the @entity922 ( @entity922 ), which was defined as 3 points. RESULTS: Compared to the normal weight, the class I @entity28 was significantly associated with better @entity283 scores in the mental component summary (MCS) (75.1 vs. 73.4, P<0.001). The underweight had the lowest score in both the physical components summary (PCS) (75.4 vs. 77.5, P<0.001) and mental components summary (MCS) (71.8 vs. 73.4, P<0.001). For the @entity922 , the @entity283 score was reduced by more than 3 points in the physical functioning for the class II @entity28 (D=-3.43) and the general health for the underweight (D=-3.71). Stratified analyses showed a similar result in the health subjects and chronic conditions, and it was significant in the chronic conditions. CONCLUSIONS: The class I @entity28 showed the best @entity283 , especially in the mental domain. The worst @entity283 was found in the underweight. The class II @entity28 reduced @entity283 in the physical functioning only. " @entity28 paradox" was more obvious in the @entity1 with chronic conditions.

Association between Body Mass Index and Health-Related Quality of Life: The " XXXX Paradox" in 21,218 Adults of the Chinese General Population.

@entity1 :: ('9606', 'Species') :: ['participants'] @entity28 :: ('MESH:D009765', 'Disease') :: ['Obesity', 'obese'] @entity922 :: ('MESH:D013568', 'Disease') :: ['minimum clinically important differences', 'MCID'] @entity283 :: ('OMIM:603663', 'Disease') :: ['HRQL', 'health related quality of life']
@entity28 :: (MESH:D009765,Disease) :: ['Obesity']
