Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada.
Hypertension. 2012 Mar;59(3):572-9. doi: 10.1161/HYPERTENSIONAHA.111.180372. Epub 2012 Jan 30.
Excess body fat deposited viscerally rather than elsewhere in the body is associated with higher risk for hypertension; this relationship is stronger in men than in women. Here we investigated whether similar sex dimorphism exists already in adolescence. A population-based sample of adolescent boys (n=237) and girls (n=262), age 12 to 18 years, was studied. Total body fat (TBF) was assessed with multifrequency bioelectrical impedance, and visceral fat (VF) was quantified with MRI. Blood pressure (BP) was measured beat by beat during an hour-long protocol, including supine, standing, sitting, mental stress, and poststress sections. Multivariate mixed-model analysis was used to assess the relative contributions of TBF and VF to BP during these sections. In boys, BP was strongly positively associated with VF (P<0.0001), whereas it was less strongly and negatively associated with TBF (P=0.004); these relationships did not substantially vary during the protocol. In contrast, in girls, BP was strongly positively associated with TBF (P=0.0006), whereas it was not associated with VF (P=0.08); the relationship with TBF varied during the protocol and was most apparent during mental stress (TBF*section interaction: P=0.002). Furthermore, when waist circumference was included in multivariate models instead of VF, it was not associated with BP in either sex; this indicates that waist circumference may not be an appropriate surrogate for VF. Thus, in adolescence, adiposity-related BP elevation is driven mainly by visceral fat in males and by fat deposited elsewhere in females. This dimorphism suggests sex-specific mechanisms of obesity-induced hypertension and the need for sex-specific criteria of its prevention.
内脏脂肪的过度堆积与高血压风险增加有关，这种关系在男性中比女性更强。在这里，我们研究了这种性别二态性是否在青少年时期就已经存在。我们对一个基于人群的青少年男孩（n=237）和女孩（n=262）样本进行了研究，年龄在 12 至 18 岁之间。使用多频生物电阻抗法评估全身脂肪（TBF），并使用 MRI 定量评估内脏脂肪（VF）。在一个长达一小时的方案中，通过逐拍测量血压（BP），包括仰卧、站立、坐着、精神压力和应激后部分。使用多元混合模型分析来评估 TBF 和 VF 在这些部分对 BP 的相对贡献。在男孩中，BP 与 VF 呈强烈的正相关（P<0.0001），而与 TBF 的相关性较弱且呈负相关（P=0.004）；这些关系在方案中没有实质性变化。相比之下，在女孩中，BP 与 TBF 呈强烈的正相关（P=0.0006），而与 VF 无关（P=0.08）；与 TBF 的关系在方案中发生变化，在精神压力期间最为明显（TBF*section 相互作用：P=0.002）。此外，当腰围代替 VF 纳入多元模型时，它与两性的 BP 均不相关；这表明腰围可能不是 VF 的合适替代物。因此，在青春期，与肥胖相关的血压升高主要由男性的内脏脂肪驱动，而女性则由其他部位的脂肪堆积驱动。这种二态性表明肥胖引起的高血压存在特定性别的机制，需要针对其预防制定特定性别的标准。
