Domain and intensity of physical activity are associated with metabolic syndrome: A population-based study

Introduction
Little is known on how the domain and intensity of physical activity (PA) associates with metabolic syndrome (MetS). The aim of this study was to examine associations between PA domains (leisure-time, domestic, active transport, total walking and total PA), PA intensities (light, moderate and vigorous) and PA levels with MetS in the general adult population.
Methods
Cross-sectional study. Anthropometry, blood biochemistry, 79-item PA-questionnaire, lifestyle and medical history were evaluated in a representative sample of Canary Island adults (n = 6,729). MetS was diagnosed using the harmonized IDF-NHLBI-AHA criteria. T-test and multivariable logistic regression was used to analyse associations between PA domains and intensities with MetS vs. no MetS, controlling for socio-demographic, lifestyle, family antecedents and body mass index (BMI).
Results
For each MET-h/day spent in moderate-vigorous PA intensities, as well as in recreational domain, active transport, total walking and total PA, the odds of MetS decreased between 3–10%. Energy expenditure exclusively in light and domestic PAs was not associated with MetS, however it was important to achieve a total PA level of 3 MET-h/day, which reduced the odds of MetS by 23%. This reduction was blunted in those with more than 2 h/d of TV watching time. A PA level of 3 MET-h/d also nullified the risk of MetS in those with low PA and high TV consumption.
Conclusions
Some types of leisure time PAs may contribute more than others to reducing MetS. Light and domestic PA play a complementary role in enhancing energy expenditure in the general population. TV watching time above 2 h/d counteracted the MetS risk reduction associated with PA level, but PA level also reduced the risk of METs presented by those with a low level of PA and an excess TV watching time. Physical activity explains a greater amount of the variance of MetS than any other factors of lifestyle, education, sex and family history, and substantially mitigates the strong association of age and BMI with MetS.

Introduction
目前学界对于体力活动（Physical Activity, PA）与代谢综合征（Metabolic Syndrome, MetS）之间的关联，尤其是体力活动的类型与强度对其的影响，尚不明晰。本研究旨在探究普通成人人群中，体力活动类型（休闲时间活动、家务活动、出行通勤活动、总步行量与总体力活动量）、体力活动强度（低强度、中强度、高强度）以及整体体力活动水平与代谢综合征之间的关联。

Methods
本研究为横断面研究。纳入加那利群岛成年人群的代表性样本（n=6729），对受试者的人体测量学指标、血液生化指标、79项体力活动调查问卷结果、生活方式与病史进行评估。代谢综合征采用统一的国际糖尿病联盟（IDF）-美国国家心肺血液研究所（NHLBI）-美国心脏协会（AHA）诊断标准进行判定。采用t检验与多因素logistic回归分析体力活动类型、强度与代谢综合征患病状态（患病vs未患病）之间的关联，并校正社会人口学因素、生活方式、家族病史与体质量指数（Body Mass Index, BMI）等混杂变量。

Results
每增加1代谢当量（MET）·小时/天的中高强度体力活动，以及休闲时间活动、出行通勤活动、总步行量与总体力活动量，代谢综合征的患病风险将降低3%~10%。仅通过低强度体力活动与家务活动消耗的能量与代谢综合征无显著关联，但达到每日总体力活动量3MET·小时/天可使代谢综合征患病风险降低23%。但若每日看电视时长超过2小时，上述风险降低效应会被削弱。对于日常体力活动水平较低且每日看电视时长过长的人群，每日总体力活动量达到3MET·小时/天也可完全抵消其代谢综合征的患病风险。

Conclusions
部分类型的休闲时间体力活动在降低代谢综合征风险方面的获益优于其他体力活动类型。低强度体力活动与家务活动在普通人群中可通过补充性方式提升能量消耗。每日看电视时长超过2小时会抵消体力活动水平带来的代谢综合征风险降低效应，但对于日常体力活动水平较低且看电视时长过长的人群，提升体力活动水平仍可降低其代谢综合征患病风险。相较于生活方式、受教育程度、性别与家族病史等其他因素，体力活动可解释更多的代谢综合征变异度，且可显著削弱年龄与体质量指数对代谢综合征的强关联效应。