Piirtola Maarit, Kaprio Jaakko, Kujala Urho M, Heikkilä Kauko, Koskenvuo Markku, Svedberg Pia, Silventoinen Karri, Ropponen Annina
Department of Public Health, University of Helsinki, PO Box 41 (Tukholmankatu 8, 2B), FI-00014, Helsinki, Finland.
Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland.
BMC Public Health. 2016 Aug 4;16:720. doi: 10.1186/s12889-016-3410-5.
Education is associated with health related lifestyle choices including leisure-time physical inactivity. However, the longitudinal associations between education and inactivity merit further studies. We investigated the association between education and leisure-time physical inactivity over a 35-year follow-up with four time points controlling for multiple covariates including familial confounding.
This study of the population-based Finnish Twin Cohort consisted of 5254 twin individuals born in 1945-1957 (59 % women), of which 1604 were complete same-sexed twin pairs. Data on leisure-time physical activity and multiple covariates was available from four surveys conducted in 1975, 1981, 1990 and 2011 (response rates 72 to 89 %). The association between years of education and leisure-time physical inactivity (<1.5 metabolic equivalent hours/day) was first analysed for each survey. Then, the role of education was investigated for 15-year and 35-year inactivity periods in the longitudinal analyses. The co-twin control design was used to analyse the potential familial confounding of the effects. All analyses were conducted with and without multiple covariates. Odds Ratios (OR) with 95 % Confidence Intervals (CI) were calculated using logistic and conditional (fixed-effects) regression models.
Each additional year of education was associated with less inactivity (OR 0.94 to 0.95, 95 % CI 0.92, 0.99) in the cross-sectional age- and sex-adjusted analyses. The associations of education with inactivity in the 15- and 35-year follow-ups showed a similar trend: OR 0.97 (95 % CI 0.93, 1.00) and OR 0.94 (95 % CI 0.91, 0.98), respectively. In all co-twin control analyses, each year of higher education was associated with a reduced likelihood of inactivity suggesting direct effect (i.e. independent from familial confounding) of education on inactivity. However, the point estimates were lower than in the individual-level analyses. Adjustment for multiple covariates did not change these associations.
Higher education is associated with lower odds of leisure-time physical inactivity during the three-decade follow-up. The association was found after adjusting for several confounders, including familial factors. Hence, the results point to the conclusion that education has an independent role in the development of long-term physical inactivity and tailored efforts to promote physical activity among lower educated people would be needed throughout adulthood.
教育与包括休闲时间身体活动不足在内的健康相关生活方式选择有关。然而，教育与身体活动不足之间的纵向关联值得进一步研究。我们在35年的随访中，通过四个时间点，控制包括家族性混杂因素在内的多个协变量，研究了教育与休闲时间身体活动不足之间的关联。
这项基于芬兰双胞胎队列人群的研究包括5254名出生于1945年至1957年的双胞胎个体（59%为女性），其中1604对是完全同性别的双胞胎。1975年、1981年、1990年和2011年进行的四项调查提供了休闲时间身体活动和多个协变量的数据（应答率为72%至89%）。首先对每次调查分析教育年限与休闲时间身体活动不足（<1.5代谢当量小时/天）之间的关联。然后，在纵向分析中研究教育对15年和35年身体活动不足期的作用。采用同卵双胞胎对照设计分析效应的潜在家族性混杂因素。所有分析均在有和没有多个协变量的情况下进行。使用逻辑回归和条件（固定效应）回归模型计算95%置信区间（CI）下的比值比（OR）。
在横断面年龄和性别调整分析中,每增加一年教育与身体活动不足减少相关（OR为0.94至0.95，95%CI为0.92,0.99）在15年和35年随访中教育与身体活动不足的关联呈现相似趋势：分别为OR 0.97（95%CI 0.93,1.00）和OR 0.94（95%CI 0.91,0.98）。在所有同卵双胞胎对照分析中，每增加一年高等教育与身体活动不足可能性降低相关，提示教育对身体活动不足有直接影响（即独立于家族性混杂因素）。然而，点估计值低于个体水平分析。对多个协变量进行调整并没有改变这些关联。
在三十年的随访中，高等教育与休闲时间身体活动不足的较低几率相关。在调整了包括家族因素在内的几个混杂因素后发现了这种关联。因此，结果表明教育在长期身体活动不足的发展中具有独立作用，在整个成年期需要针对性地努力促进受教育程度较低人群的身体活动。
