Grandjean Philippe, Murata Katsuyuki, Budtz-Jørgensen Esben, Weihe Pál
Institute of Public Health, University of Southern Denmark, Odense, Denmark.
J Pediatr. 2004 Feb;144(2):169-76. doi: 10.1016/j.jpeds.2003.10.058.
To determine whether heart function in childhood is affected by exposure to methylmercury (MeHg) from seafood.
Prospective study of a Faroese birth cohort (N=1022). Examinations at ages 7 and 14 years included blood pressure, heart rate variability (HRV) and its frequency components of autonomic origin, and brainstem auditory evoked potentials (BAEPs). Mercury concentrations were determined in cord blood and in the child's hair.
Both low-frequency (LF) and high-frequency (HF) activities decreased by about 25% from 7 to 14 years; they correlated well with the blood pressures. A doubling of prenatal MeHg exposure was associated with a decrease in LF and HF powers of about 6.7% (P=.04) and in the coefficient of variation of the electrocardiographic R-R interval of 2.7% (P=.04) at age 14 years. No discernible effect on blood pressure was apparent. Decreased LF variability was associated with increased latency of BAEP peak III, but adjustment for MeHg exposure substantially attenuated this correlation.
Methylmercury exposure was associated with decreased sympathetic (LF) and parasympathetic (HF) modulation of the HRV. Parallel MeHg-related delays of BAEP latencies may be caused by underlying MeHg neurotoxicity to brainstem nuclei.
确定儿童时期的心脏功能是否会受到海产品中甲基汞（MeHg）暴露的影响。
对法罗群岛出生队列（N = 1022）进行前瞻性研究。7岁和14岁时的检查包括血压、心率变异性（HRV）及其自主神经起源的频率成分，以及脑干听觉诱发电位（BAEP）。测定脐带血和儿童头发中的汞浓度。
低频（LF）和高频（HF）活动从7岁到14岁均下降了约25%；它们与血压密切相关。产前甲基汞暴露量翻倍与14岁时LF和HF功率下降约6.7%（P = 0.04）以及心电图R-R间期变异系数下降2.7%（P = 0.04）相关。未发现对血压有明显影响。LF变异性降低与BAEP峰III潜伏期延长有关，但对甲基汞暴露进行校正后，这种相关性明显减弱。
甲基汞暴露与HRV的交感神经（LF）和副交感神经（HF）调节降低有关。与甲基汞相关的BAEP潜伏期平行延迟可能是由于甲基汞对脑干核的潜在神经毒性所致。
