BACKGROUND Roux-en-Y Gastric Bypass (RYGB) patients overestimate their time spent in moderate-to-vigorous physical activity (MVPA) to a greater extent post-surgery than pre-surgery. However, there is no data on discrepancy between self-reported and accelerometer-measured MVPA beyond nine months post-RYGB. The aim was to investigate how the duration of MVPA (main outcome) differs when comparing a self-administered questionnaire to accelerometer-data from pre-surgery and up to 48 months post-RYGB. METHODS Twenty-six (38%) RYGB-treated women with complete data from the original cohort (N = 69) were included. Participants were recruited from five Swedish hospitals. Mean pre-surgery BMI was 38.9 (standard deviation (SD) = 3.4) kg/m2 and mean age 39.9 (SD = 6.5) years. MVPA was subjectively measured by a self-administered questionnaire and objectively measured by the ActiGraph GT3X+ accelerometer at 3 months pre-RYGB and 9- and 48 months post-RYGB. Means and SD were calculated at 3 months pre- and 9- and 48 months post-RYGB. We calculated the P-values of the differences with Wilcoxon Signed-Rank test. For correlations between the self-administered questionnaire and the accelerometers, Spearman's rank correlation was used. RESULTS Participants significantly overestimated (i.e. self-reported more time spent in MVPA compared to accelerometry) their MVPA in a higher degree post- compared to pre-RYGB surgery. Compared to pre-surgery, self-reported MVPA increased with 46.9 and 36.5% from pre- to 9- and 48 months, respectively, whereas changes were a 6.1% increase and 3.5% decrease with accelerometers. Correlations between self-reported and accelerometer-measured MVPA-assessments were poor at all measurement points (r = 0.21-0.42) and only significant at 48 months post-RYGB (P = 0.032). CONCLUSIONS The discrepancy between self-reported and objectively assessed MVPA within the same individual is greater up to 48 months post-RYGB compared to before surgery. To help bariatric patients understand and hopefully increase their physical activity behaviors post-surgery, objective measures of physical activity should be used.

中文翻译：

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Roux-en-Y胃绕道手术之前和之后48个月内，女性使用加速度计测得的身体活动水平与自我报告的身体活动水平进行比较。

背景技术Roux-en-Y胃旁路手术（RYGB）患者在手术后比手术前更大程度地高估了他们在中度至剧烈身体活动（MVPA）上花费的时间。但是，在RYGB之后的9个月内，没有关于自我报告的和加速度计测量的MVPA之间差异的数据。目的是研究将自我管理的问卷与手术前和RYGB后48个月内的加速度计数据进行比较时，MVPA（主要结局）的持续时间有何不同。方法包括26名（38％）经RYGB治疗的女性，其原始数据完整（N = 69）。参与者来自瑞典的五家医院。术前平均BMI为38.9（标准差（SD）= 3.4）kg / m2，平均年龄为39.9（SD = 6.5）年。在RYGB之前3个月以及RYGB之后9个月和48个月时，通过自我管理的问卷主观测量MVPA，并通过ActiGraph GT3X +加速度计客观地测量MVPA。在RYGB之前3个月，9个月和48个月后计算平均值和SD。我们用Wilcoxon Signed-Rank检验计算了差异的P值。对于自填式问卷和加速度计之间的相关性，使用了Spearman等级相关性。结果与RYGB手术之前相比，参与者在更高程度的评估中大大高估了他们的MVPA（即，自我报告的MVPA时间比加速度计更多）。与手术前相比，自我报告的MVPA从手术前到手术后9个月和48个月分别增加了46.9％和36.5％，而使用加速度计的变化分别增加了6.1％和3.5％。自我报告的和加速度计测量的MVPA评估之间的相关性在所有测量点均很差（r = 0.21-0.42），仅在RYGB后48个月时才显着（P = 0.032）。结论与手术前相比，RYGB术后长达48个月，同一个体中自我报告的和客观评估的MVPA之间的差异更大。为了帮助减肥患者了解并希望增加他们在手术后的体育锻炼行为，应使用体育锻炼的客观测量方法。结论与手术前相比，RYGB术后长达48个月，同一个体中自我报告的和客观评估的MVPA之间的差异更大。为了帮助减肥患者理解并希望增加他们在手术后的体育锻炼行为，应使用体育锻炼的客观测量方法。结论与手术前相比，RYGB术后长达48个月，同一个体中自我报告的和客观评估的MVPA之间的差异更大。为了帮助减肥患者理解并希望增加他们在手术后的体育锻炼行为，应使用体育锻炼的客观测量方法。