Socioeconomic Inequalities in Body Mass Index across Adulthood: Coordinated Analyses of Individual Participant Data from Three British Birth Cohort Studies Initiated in 1946, 1958 and 1970.
Socioeconomic Inequalities in Body Mass Index across Adulthood: Coordinated Analyses of Individual Participant Data from Three British Birth Cohort Studies Initiated in 1946, 1958 and 1970.
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DOI：
10.1371/journal.pmed.1002214
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发表时间：
2017-01
期刊：
影响因子：
15.8
通讯作者：
Hardy R
中科院分区：
文献类型：
--
作者：
Bann D;Johnson W;Li L;Kuh D;Hardy R
高身体质量指数（BMI）是造成全球健康不良和健康不平等负担的一个重要因素。儿童期和成年期较低的社会经济地位（SEP）与成年期较高的BMI相关，但这些关联如何随时间变化却知之甚少。我们使用纵向数据来研究英国三个国家出生队列中儿童和成人SEP与成年期BMI之间的关系。样本包括22,810名参与者，在1946年MRC全国健康与发展调查（20至60-64岁），1958年全国儿童发展研究（23至50岁）和1970年英国队列研究（26至42岁）中观察到77115个BMI值。在童年时期（父亲10/11岁时）和成年期（42/43岁），以及成年期（1966年至2012年）反复确定了基于社会阶层的统一SEP数据（注册官的社会阶层），并重复确定了BMI。使用线性回归和多水平模型检验SEP和BMI之间的关系。在两性中，儿童期较低的SEP与成年期较高的BMI相关，并且在年龄较大时差异通常较大，在每个队列中差异的幅度相似。在这些队列中，成人SEP和BMI之间的关联强度没有随年龄变化而变化，但在女性中比男性更明显，1970年队列中的女性与更早出生的队列相比，不平等更大。例如，1946年NSHD中最低社会阶层与最高社会阶层女性42/43岁时BMI的平均差异为2.0 kg/m2 (95% CI: - 0.1, 4.0)， 1958年NCDS中为2.3 kg/m2(1.1, 3.4)， 1970年BCS中为3.9 kg/m2 (2.3, 5.4)；最高和最低社会阶层的平均BMI （SD）如下：1946年NSHD为24.9（0.8）对26.8(0.7)，1958年NCDS为24.2（0.4）对26.5(0.4)，1970年BCS为24.2（0.3）对28.1（0.8）。无论以超重还是肥胖作为研究结果，研究结果都没有差异。这项工作的局限性包括使用社会阶层作为SEP的唯一指标，虽然它在儿童和成年的每个队列中都可用，但BMI不平等的趋势可能会根据SEP的其他维度（如教育或收入）而有所不同。虽然统一的数据被用来帮助推断出生队列在BMI不平等方面的差异，但其他因素的差异也可能对研究结果有所贡献——例如，缺失数据的差异。考虑到这些持续存在的不平等及其对公共健康的影响，迫切需要新的有效政策来减少成人BMI不平等，解决儿童和成人SEP不平等问题。在对三个队列的社会经济和人体测量数据进行协调分析后，David Bann及其同事追踪了英国社会经济地位与BMI之间的关系。高身体质量指数（BMI）被认为对人体健康有害——对大多数成年人来说，高身体质量指数是由于体内有大量的脂肪。先前的研究发现，那些社会经济资源较少的人——无论是在儿童时期还是成年时期——成年后的平均体重指数更有可能更高。减少BMI中的这些社会经济不平等是一项重要的卫生政策目标，但现有数据有限，无法帮助我们全面了解这些不平等是如何随着时间的推移而变化的。我们使用了三个英国国家出生队列研究的数据，这些研究的对象是1946年、1958年和1970年出生的人——这些研究包含了童年和成年时期社会阶层以及成年后身体质量指数的可比数据。我们证实，根据儿童和成人的体重指数，BMI存在很大的不平等——这种不平等在女性中更为明显，但在男性中也存在。在所有队列和男女中，儿童期SEP的不平等通常在年龄较大时逐渐加剧；在最近出生的几代女性中，成年SEP的不平等更大。尽管有旨在减少BMI不平等的政策，但BMI不平等在不同世代之间持续存在或加剧，这一事实表明，需要出台新的政策。研究结果支持有必要在成年后更早而不是更晚进行干预，因为年龄越大，不平等现象往往越严重。局限性包括只使用了社会经济环境的一个方面（社会阶层），以及并非所有参与者都继续在纵向研究中提供数据的事实——这可能导致我们低估了BMI不平等的程度。
High body mass index (BMI) is an important contributor to the global burden of ill-health and health inequality. Lower socioeconomic position (SEP) in both childhood and adulthood is associated with higher adult BMI, but how these associations have changed across time is poorly understood. We used longitudinal data to examine how childhood and adult SEP relates to BMI across adulthood in three national British birth cohorts. The sample comprised up to 22,810 participants with 77,115 BMI observations in the 1946 MRC National Survey of Health and Development (ages 20 to 60–64), the 1958 National Child Development Study (ages 23 to 50), and the 1970 British Cohort Study (ages 26 to 42). Harmonized social class-based SEP data (Registrar General’s Social Class) was ascertained in childhood (father’s class at 10/11 y) and adulthood (42/43 years), and BMI repeatedly across adulthood, spanning 1966 to 2012. Associations between SEP and BMI were examined using linear regression and multilevel models. Lower childhood SEP was associated with higher adult BMI in both genders, and differences were typically larger at older ages and similar in magnitude in each cohort. The strength of association between adult SEP and BMI did not vary with age in any consistent pattern in these cohorts, but were more evident in women than men, and inequalities were larger among women in the 1970 cohort compared with earlier-born cohorts. For example, mean differences in BMI at 42/43 y amongst women in the lowest compared with highest social class were 2.0 kg/m2 (95% CI: −0.1, 4.0) in the 1946 NSHD, 2.3 kg/m2 (1.1, 3.4) in the 1958 NCDS, and 3.9 kg/m2 (2.3, 5.4) the in the 1970 BCS; mean (SD) BMI in the highest and lowest social classes were as follows: 24.9 (0.8) versus 26.8 (0.7) in the 1946 NSHD, 24.2 (0.4) versus 26.5 (0.4) in the 1958 NCDS, and 24.2 (0.3) versus 28.1 (0.8) in the 1970 BCS. Findings did not differ whether using overweight or obesity as an outcome. Limitations of this work include the use of social class as the sole indicator of SEP—while it was available in each cohort in both childhood and adulthood, trends in BMI inequalities may differ according to other dimensions of SEP such as education or income. Although harmonized data were used to aid inferences about birth cohort differences in BMI inequality, differences in other factors may have also contributed to findings—for example, differences in missing data. Given these persisting inequalities and their public health implications, new and effective policies to reduce inequalities in adult BMI that tackle inequality with respect to both childhood and adult SEP are urgently required In a harmonized analysis of socioeconomic and anthropometric data from three cohorts, David Bann and colleagues trace the relationship between socioeconomic status and BMI over time in the UK. High body mass index (BMI) is thought to be harmful to human health—in most adults, a high BMI is due to having high amounts of fat mass in the body. Previous studies have found that those with fewer socioeconomic resources—both as children and as adults—are more likely, on average, to have a higher BMI as adults. Reducing these socioeconomic inequalities in BMI is an important health policy goal, yet there is limited existing data to help us understand comprehensively how these inequalities have changed across time. We used data from three national British birth cohort studies of those born in 1946, 1958, and 1970—these studies contain comparable data on social class in childhood and adulthood, and on BMI across adult life. We confirm that large inequalities in BMI exist, according to both childhood and adult SEP—these were stronger among women, but also found among men. Inequalities according to childhood SEP generally become progressively larger at older ages in all cohorts and in both genders; inequalities according to adult SEP were larger among more recently born generations of women. The fact that BMI inequalities have persisted or increased across different generations, despite policies designed to reduce them, suggests that new policies are required. Results support the need to intervene earlier rather than later in adult life, since inequalities tend to become larger at older ages. Limitations include the use of only one aspect of socioeconomic circumstances (social class), and the fact that not all participants continue to provide data in longitudinal studies—this may have led us to underestimating the size of BMI inequalities.