负性情绪可导致青少年血压模式异常

迈阿密海滩——Tanisha I. Burford博士在国际黑人高血压学会年会上报告，夜间非杓型血压是一种公认的高血压危险因素，一项研究显示，这种现象早在青春期即可出现，尤其是在黑人青少年中较多见，并且与较低的社会经济地位相关。此外，负性心理，如特质愤怒和人际冲突是夜间非杓型血压的独立危险因素。

一般情况下，血压在早晨较低，在白天升高，并在夜间降低。夜间非杓型血压定义为夜间较白天血压降低不足10%。尽管血压读数变化很大，并且受到多种因素的影响，但≤10%的切点是一种可靠的风险预测因子。“我们所了解的非杓型血压信息多数来自成人研究。”有证据显示，夜间血压降低的情况“在青春期即已出现，甚至一些9~11岁的儿童就有这种血压变化模式，”匹兹堡大学心血管行为医学研究项目的Burford博士说。

Tanisha Burford博士

在这项研究中，Burford博士及其同事要求139名黑人和106名白人健康青少年连续48 h佩戴动态血压监测仪，参与者年龄为14~19岁(中位年龄16岁)，来自匹兹堡血压计划II。在每次读取血压测定结果之前的10分钟内，受试者使用电子日记评定社会关系和任何冲突(基于6分制量表)。参与者还要完成标准抑郁症(流行病学研究中心抑郁症量表或CES-D)、特质愤怒(国家特质愤怒目录或STAI)和负性影响(正性与负性影响方案或PANAS)评定。

研究者发现，与一项校正年龄、性别和体重指数的回归分析中的白人青少年相比，报告负性情绪和(或)冲突发生率较高的黑人青少年的平均夜间:白天血压(包括收缩压和舒张压)比值较高。“多数为收缩压效应，这对于高血压很有意义，因为在早期收缩压的变化的危害更大。”

在黑人中，关于特质愤怒的β值(平均收缩压夜间/白天比值与种族之间的相互作用)为0.43，关于负性影响的β值为0.52，关于抑郁症的β值为0.59，均具有统计学意义。人际关系紧张和种族之间的相互作用对于收缩压比值(β值为0.38)具有不良影响趋势，但无统计学意义。

“最令人关注的结果是负性心理与种族之间的相互作用，”Burford博士说。特质愤怒、抑郁症和种族仅与黑人青少年的夜间非杓型血压相关，但白人青少年中也报告有较高的特质愤怒水平。一个可能的解释是，正性心理对于黑人青少年的保护作用较小。

研究者总结认为，负性情绪可能导致青少年非杓型血压，并且对于黑人青少年的影响较大。

Burford博士披露无相关利益冲突。

爱思唯尔  版权所有

By: DAMIAN MCNAMARA, Cardiology News Digital Network

MIAMI BEACH  – Nondipping of nighttime blood pressure – a recognized risk factor for hypertension – emerges as early as adolescence, preferentially affects blacks, and is associated with lower socioeconomic status, according to a study.

In addition, negative psychological attributes such as trait anger and interpersonal conflict by day were independent factors for blood pressure nondipping at night, Tanisha I. Burford, Ph.D., said at the annual meeting of the International Society on Hypertension in Blacks.

Dr. Burford recommended asking potentially at-risk adolescent patients about their sleep quality, because those with fragmented or interrupted sleep are less likely to experience a normal, nocturnal restorative decline in blood pressure.

She also suggested that clinicians consider asking at-risk adolescents to wear an ambulatory blood pressure monitor for more-comprehensive, real-time feedback on circadian blood pressures, compared with conventional intermittent clinical readings.

Dr. Burford and her colleagues did just that – they asked 139 black and 106 white healthy adolescents to wear ambulatory blood pressure monitors for 48 consecutive hours.

"Most of what we know about nondipping blood pressure is [from studies] in adults." There is some evidence that blunting of blood pressure decreases at night "emerges early in the life course, during adolescence, and even in some children 9-11 years old," said Dr. Burford, a postdoctoral scholar in the cardiovascular behavioral medicine research program at the University of Pittsburgh.

Study participants used electronic diaries to rate social interactions and any conflict (on a 6-point scale) in the 10 minutes preceding each blood pressure reading. They also completed standard measures of depression (Center for Epidemiologic Studies Depression scale or CES-D); trait anger (State Trait Anxiety Inventory or STAI), and negative affect (Positive and Negative Aspect Schedule or PANAS).

The researchers found a higher ratio of average night to day blood pressures (both systolic and diastolic) among black teenagers who reported higher rates of negative emotions and/or conflict compared to white teenagers in a regression analysis that adjusted for age, sex, and body mass index.

"Most of this is a systolic effect – which makes sense for hypertension – [where] systolic changes are more detrimental in early stages," Dr. Burford said.

Among blacks, the beta value (the interaction between average systolic blood pressure night/day ratio and race) was a significant 0.43 for trait anger; a significant 0.52 for negative affect; and a significant 0.59 for depression.

The interaction between interpersonal stress and race had a nonsignificant trend for an adverse effect on the systolic blood pressure ratio (beta value, 0.38).

"The most fascinating thing is that these negative psychological attributes did [interact with] race," Dr. Burford said. Trait anger, depression, and conflict were only associated with nighttime nondipping of blood pressure among black teens, even though white teens reported higher levels of trait anger. A possible explanation, she added, was that positive attributes were less protective for black teenagers.

Some blacks have a "lower resource capacity," Dr. Burford said, which could include lower levels of self-esteem and less social support, particularly if they live in a stressful environment.

Participants were 14-19 years old (median, 16 years) and part of the Pittsburgh Project Pressure II.

Typically, blood pressure is low during the morning, increases during the day, and then drops at nighttime. Nondipping nighttime blood pressure was defined as less than a 10% decrease vs. daytime pressures. Although blood pressure readings can be highly variable and influenced by multiple factors, this 10% or less cutoff is a reliable predictor of risk, Dr. Burford said.

Dr. Burford had no relevant financial disclosures.