Institute of Preventive Medicine, Copenhagen University Hospital Copenhagen, Denmark.
Front Genet. 2012 Jul 18;3:125. doi: 10.3389/fgene.2012.00125. eCollection 2012.
The genetic predisposition to obesity may have contributed to the obesity epidemic through assortative mating. We investigated whether spouses were positively assorted by body mass index (BMI; = kg/m(2)) in late childhood, and whether changes in assorted marriage by upper BMI-percentiles occurred during the obesity epidemic.
In the Copenhagen School Health Records Register (CSHRR) boys and girls with measures of BMI at age 13 years later became 37,792 spousal-pairs who married between 1945 and 2010. Trends in the spousal BMI correlations using sex-, age-, and birth cohort-specific BMI z-scores across time were investigated. Odds ratios (ORs) of marriage among spouses both with BMI z-scores >90th or >95th percentile compared with marriage among spouses ≤90th percentile were analyzed for marriages entered during the years prior to (1945-1970), and during the obesity epidemic (1971-2010).
Spousal BMI correlations were around 0.05 and stayed similar across time. ORs of marriage among spouses with BMIs >90th percentile at age 13 were 1.21, 1.05-1.39, in 1945-1970, and increased to 1.63, 1.40-1.91, in 1971-2010 (p = 0.006). ORs of marriage among spouses both >95th BMI percentile were higher and increased more; from 1.39, 1.10-1.81, to 2.39, 1.85-3.09 (p = 0.004).
Spousal correlations by pre-marital BMIs were small and stable during the past 65 years. Yet, there were assorted marriages between spouses with high BMI at age 13 years and the tendency increased alongside with the obesity epidemic which may increase the offsprings' predisposition to obesity.
肥胖的遗传倾向可能通过选择性交配导致肥胖流行。我们研究了儿童后期体重指数（BMI；=kg/m2）是否使配偶呈正相关，以及在肥胖流行期间，BMI 百分位数的变化是否改变了婚姻的选择性。
在哥本哈根学校健康记录登记处（CSHRR），13 岁时测量 BMI 的男孩和女孩后来成为 37792 对配偶，他们在 1945 年至 2010 年间结婚。通过性别、年龄和出生队列特异性 BMI z 分数随时间的变化，研究了配偶 BMI 相关性的趋势。分析了在肥胖流行前（1945-1970 年）和肥胖流行期间（1971-2010 年）进入婚姻的配偶中，BMI z 分数>90 或>95 百分位数的配偶与 BMI z 分数≤90 百分位数的配偶之间的婚姻的比值比（OR）。
配偶 BMI 相关性约为 0.05，且随时间保持相似。13 岁时 BMI>90 百分位数的配偶的婚姻 OR 在 1945-1970 年为 1.21、1.05-1.39，而在 1971-2010 年增加到 1.63、1.40-1.91（p=0.006）。BMI>95 百分位数的配偶的婚姻 OR 更高且增加更多；从 1.39、1.10-1.81 增加到 2.39、1.85-3.09（p=0.004）。
65 年来，婚前 BMI 使配偶呈正相关，相关性虽小但稳定。然而，在 13 岁时 BMI 较高的配偶之间存在选择性婚姻，且这种趋势随着肥胖流行而增加，这可能增加后代肥胖的易感性。
