Pietiläinen Kirsi H, Rissanen Aila, Laamanen Maria, Lindholm Anna-Kaisa, Markkula Harri, Yki-Järvinen Hannele, Kaprio Jaakko
The Finnish Twin Cohort Study, Department of Public Health, University of Helsinki, Finland.
Twin Res. 2004 Oct;7(5):421-9. doi: 10.1375/1369052042335368.
Weight discordance is very rare in monozygotic (MZ) twin pairs; when found, however, such pairs are advantageous in the search for either environmental or epigenetic causes and consequences of obesity. We analyzed the growth patterns of young adult MZ pairs discordant and concordant for obesity. Screening 5 consecutive birth cohorts (1975-1979) of 22- to 27-year-old Finnish twins (the FinnTwin16 study), we found 14 obesity discordant (Body Mass Index [BMI] difference > or = 4 kg/m2) MZ pairs out of 658. Ten pairs participated in clinical studies. Nine concordant pairs (BMI difference < or = 2 kg/m2) were examined as controls. Lifetime measured heights and weights recorded in hospitals and health centers were traced manually. Height development was similar in all the co-twins of both groups. The weight differences between the co-twins of the discordant pairs began to emerge at 18 years leading to an average discordance of 16.4 kg, 5.6 kg/m2 (p for both = .005) at 25.7 years. The heavier co-twin weighed 221 g (p = .066), 1.0 kg/m2 (p = .01) more already at birth than the leaner, but the differences waned by 6 months of age and reappeared only after adolescence. Both the leaner and the heavier co-twins of the discordant pairs weighed more than expected by the singleton reference values (Cole et al., 1998) after 8 years. The concordant co-twins, on the other hand, grew similarly and after 6 months, their mean growth was not distinguishable from the singleton patterns. Young adulthood represents a critical period of gaining weight irrespective of genetic background in this twin sample.
体重不一致在同卵（MZ）双胞胎中非常罕见；然而，一旦发现，这类双胞胎对于探寻肥胖的环境或表观遗传原因及后果很有帮助。我们分析了肥胖不一致和一致的年轻成年MZ双胞胎的生长模式。通过筛查连续5个出生队列（1975 - 1979年）中22至27岁的芬兰双胞胎（芬兰双胞胎16研究），我们在658对双胞胎中发现了14对肥胖不一致（体重指数[BMI]差异≥4 kg/m²）的MZ双胞胎。其中10对参与了临床研究。9对一致的双胞胎（BMI差异≤2 kg/m²）作为对照进行检查。手动追踪医院和健康中心记录的终生测量身高和体重。两组的所有双胞胎的身高发育情况相似。不一致双胞胎对中双胞胎之间的体重差异在18岁时开始显现，到25.7岁时平均差异为16.4 kg，5.6 kg/m²（两者p值均为0.005）。较胖的双胞胎在出生时就比较瘦的重221 g（p = 0.066），1.0 kg/m²（p = 0.01），但这些差异在6个月大时减小，仅在青春期后再次出现。不一致双胞胎对中较瘦和较胖的双胞胎在8岁后体重都高于单胎参考值（Cole等人，1998年）预期。另一方面，一致的双胞胎生长情况相似，6个月后，他们的平均生长情况与单胎模式无法区分。在这个双胞胎样本中，无论遗传背景如何，年轻成年期都是体重增加的关键时期。
