The reasons for the increased risk were unclear, said Kirsten Nielsen, of Aarhus Sygehus University Hospital, who reported the findings in the Journal of Epidemiology and Community Health.

• 致病几率增加的具体原因尚不清楚，这是斯克豪斯大学附属医院的克斯坦.；尼尔森说的，她已经将这一发现发表在流行病学与社区健康月刊上了。