南京市居民看电视时间与肥胖关系

Relationship between television watching and obesity:a three-year follow-up study in Nanjing

目的探讨江苏省南京市居民每周看电视时间与肥胖发生风险的关系。方法2004年7月,选取南京市的3个城区和1个乡村的35岁～居民进行健康相关的横断面调查。对体质指数(BMI)<28的人群进行3年随访观察;采用多元线性回归和多因素Logistic回归方法,分析看电视时间(h/周)与罹患肥胖风险的关联。结果基线调查时,BMI<28共3936人;完成随访2837人,随访率为72.1%。肥胖发病率为2.7%;男女性发病率分别为2.1%和3.3%。经年龄调整后,与≤7h/周相比,看电视时间为7～14,>14h/周者罹患肥胖的风险(RR)分别增加1.353和3.061倍。调整年龄和其他协变量后,看电视时间7～14,>14h/周人群发生肥胖的风险仍高于≤7h/周者,调整RR值分别为2.357,95%CI=1.126～4.934;3.639,95%CI=1.761～7.517;进一步调整基线BMI、腰围和臀围,看电视较长人群罹患肥胖风险有所降低,但差异仍有统计学意义(P<0.01)。经多因素调整,3年间看电视时间每增加1h,男女性发生肥胖的风险分别增加2.3%和4.9%。结论看电视时间越长,罹患肥胖的危险性越大,减少静坐时间和增加体力活动可预防肥胖发生。

Objective To explore whether the increase of television watching time can increase the risk of obesity in Nanjing residents. Methods Population-based corss-sectional study was conducted among local residents older than 35 years in three urban districts and one rural county in July 2004. The subjects who were non-obese in the baseline survey were selected to participate the follow-up survey in July 2007. Multiple linear regression and multivariate logistic regression analy- sis were used to estimate the incidence risk of obesity. Results Of 3 936 subjects without obesity in baseline survey,2 837 participated the follow-up survey,and the follow-up rate was 72. 1%. Three-year cumulative incidence rate of obesity was 2.7% （2. 1% in men and 2. 3% in women）. After adujsted for age,the participants watching TV per week 7-14h and 〉 14 had a significant higher risk of developing obesity compared to those watching TV ≤7h/week （ Adj. RR = 2. 353,95 % CI = 1. 186-4. 669 ;4. 061,95% CI = 2. 105 -7. 833, reapectively）. Adjusted for age and other relevant covariates, the RRs of obesity still increased gradually with the increase of the time watching TV （ adj. RR = 2. 357,95% CI = 1. 126 - 4. 934; 3.639,95 % CI = 1.761 - 7. 517 for 7 - 14 and 〉 14h/week, respectively）. After additional adjustment for baseline BMI, WC and HC,the positive associations were attenuated but remained statistically significant. In multivariate logistic regression analysis, each 1 hr/wk increse in TV watching time was associated with 2. 3% and 4. 9% increase in likelihood of obesity for the men and women in the study,respectively. Conclusion Sedentary lifestyle indicated by prolonged TV watching time is related to significantly elevated risk of obesity. Our f＇mdings suggest the importance of reducing sedentary behavior in the prevention of obesity.