肥胖血压正常受试者的心率和血压变异性

Heart rate and blood pressure variability in obese normotensive subjects.

作者信息

Piccirillo G, Vetta F, Viola E, Santagada E, Ronzoni S, Cacciafesta M, Marigliano V

机构信息

I Clinica Medica, University of Rome, La Sapienza, Italy.

出版信息

Int J Obes Relat Metab Disord. 1998 Aug;22(8):741-50. doi: 10.1038/sj.ijo.0800650.

DOI:10.1038/sj.ijo.0800650

PMID:9725633

Abstract

OBJECTIVE

To assess autonomic modulation of cardiovascular activity in massively obese subjects.

DESIGN

Cross-sectional clinical study.

SUBJECTS

43 age-matched normotensive subjects: 15 moderately obese (body mass index (BMI) < 40); 14 massively obese (BMI > 40) and 14 nonobese controls (BMI < 26).

MEASUREMENTS

Using power spectral analysis, heart rate and arterial pressure variability were determined at rest and after sympathetic stress (tilt). Two spectral components were analysed: a low-frequency (LF) component at around 0.1 Hz, predominantly reflecting sympathetic modulation and a high-frequency (HF) component at around 0.26 Hz, reflecting parasympathetic modulation.

RESULTS

Spectral data for heart rate showed that the massively obese subjects had lower LF [mean +/- s.e.m.] normalized units (NUs) at rest (35.1 +/- 0.9) and after tilt (56.1 +/- 2.1), than the moderately obese subjects (LF NUs at rest 53.9 +/- 4.2, P < 0.001; LF NUs tilt: 66.8 +/- 5.6, P < 0.001) and nonobese control subjects (LF NUs at rest, 56.6 +/- 3.0, P < 0.001); (LF NUs tilt: 81.7 +/- 1.7, P < 0.001). Data for systolic arterial pressure variability measured at rest exhibited the inverse pattern, the massively obese group having higher mean LF values (LF mm Hg2 rest: 15.0 +/- 1.4; LF mm Hg2 tilt: 15.7 +/- 1.5) than the moderately obese group (LF mm Hg2 rest 3.2 +/- 0.7, P < 0.001; LF mm Hg2 tilt: 7.2 +/- 2.0, P < 0.001) and than the nonobese control subjects (LF mm Hg2 rest 3.5 +/- 0.5, LF mm Hg2 tilt 8.5 +/- 0.8, P < 0.001). Regression detected a significant association between BMI and LF of systolic pressure (beta = 0.364; P = 0.0007), In LF of heart rate (beta = -5.555; P = 0.00001) and very low frequency (VLF) of diastolic pressure (beta = -3.305; P = 0.0020).

CONCLUSION

Obesity seems to increase sympathetic modulation of arterial pressure, but diminishes modulation of heart rate. Because our obese subjects had high plasma noradrenaline levels, their low LF power of heart rate could reflect diminished adrenoceptor responsiveness.

摘要

目的

评估极度肥胖受试者心血管活动的自主神经调节。

设计

横断面临床研究。

受试者

43名年龄匹配的血压正常受试者：15名中度肥胖者（体重指数（BMI）<40）；14名极度肥胖者（BMI>40）和14名非肥胖对照者（BMI<26）。

测量

采用功率谱分析，在静息状态和交感神经应激（倾斜试验）后测定心率和动脉压变异性。分析了两个频谱成分：约0.1Hz的低频（LF）成分，主要反映交感神经调节；约0.26Hz的高频（HF）成分，反映副交感神经调节。

结果

心率频谱数据显示，极度肥胖受试者静息时（35.1±0.9）和倾斜试验后（56.1±2.1）的归一化低频（LF）单位（NUs）低于中度肥胖受试者（静息时LF NUs为53.9±4.2，P<0.001；倾斜试验时LF NUs为66.8±5.6，P<0.001）和非肥胖对照受试者（静息时LF NUs为56.6±3.0，P<0.001；倾斜试验时LF NUs为81.7±1.7，P<0.001）。静息时测量的收缩压变异性数据呈现相反模式，极度肥胖组的平均LF值较高（静息时LF mmHg²为15.0±1.4；倾斜试验时LF mmHg²为15.7±1.5），高于中度肥胖组（静息时LF mmHg²为3.2±0.7，P<0.001；倾斜试验时LF mmHg²为7.2±2.0，P<0.001）和非肥胖对照受试者（静息时LF mmHg²为3.5±0.5，倾斜试验时LF mmHg²为8.5±0.8，P<0.001）。回归分析发现BMI与收缩压的LF之间存在显著关联（β=0.364；P=0.0007），心率的LF（β=-5.555；P=0.00001）和舒张压的极低频（VLF）（β=-3.305；P=0.0020）。