Sydney School of Public Health, University of Sydney, Sydney, New South Wales, Australia.
School of Mathematics and Statistics, University of Sydney, Sydney, New South Wales, Australia.
PLoS One. 2018 Apr 11;13(4):e0194084. doi: 10.1371/journal.pone.0194084. eCollection 2018.
Blood pressure variability (BPV) has been associated with risk of cardiovascular events in observational studies, independently of mean BP levels. In states with higher autonomic imbalance, such as in diabetes, the importance of BP variability may theoretically be even greater. We aimed to investigate the incremental value of BPV for prediction of cardiovascular and all-cause mortality in patients with type 2 diabetes.
We identified 9,855 patients without pre-existing cardiovascular disease who did not change BP-lowering treatment during the observation period from a Swedish primary health care cohort of patients with type 2 diabetes. BPV was summarized as the standard deviation (SD), coefficient of variation (CV), or variation independent of mean (VIM). Patients were followed for a median of 4 years and associations with cardiovascular and all-cause mortality were investigated using Cox proportional hazards models.
BPV was not associated with cardiovascular specific or all-cause mortality in the total sample. In patients who were not on BP-lowering drugs during the observation period (n = 2,949), variability measures were associated with all-cause mortality: hazard ratios were 1.05, 1.04 and 1.05 for 50% increases in SD, CV and VIM, respectively, adjusted for Framingham risk score risk factors, including mean BP. However, the addition of the variability measures in this subgroup only led to very minimal improvement in discrimination, indicating they may have limited clinical usefulness (change in C-statistic ranged from 0.000-0.003 in all models).
Although BPV was independently associated with all-cause mortality in diabetes patients in primary care who did not have pre-existing cardiovascular disease or BP-lowering drugs, it may be of minimal clinical usefulness above and beyond that of other routinely measured predictors, including mean BP.
血压变异性（BPV）与心血管事件风险相关，在观察性研究中，BPV 独立于平均血压水平。在自主神经失衡程度较高的状态下，如糖尿病，BP 变异性的重要性理论上可能更大。我们旨在研究 BPV 对预测 2 型糖尿病患者心血管和全因死亡率的增量价值。
我们从一个瑞典初级保健 2 型糖尿病患者队列中确定了 9855 名没有心血管疾病且在观察期间没有改变降压治疗的患者。BPV 用标准差（SD）、变异系数（CV）或均值独立变异（VIM）来表示。患者中位随访 4 年，使用 Cox 比例风险模型调查心血管和全因死亡率的相关性。
BPV 与全队列的心血管特定死亡率或全因死亡率无关。在观察期间未服用降压药物的患者（n=2949）中，变异度指标与全因死亡率相关：SD、CV 和 VIM 分别增加 50%时，风险比分别为 1.05、1.04 和 1.05，调整了 Framingham 风险评分危险因素，包括平均血压。然而，在该亚组中加入这些变异度指标仅导致了非常微小的区分度改善，表明它们可能具有有限的临床实用性（所有模型的 C 统计量变化范围为 0.000-0.003）。
尽管在没有心血管疾病或降压药物的初级保健 2 型糖尿病患者中，BPV 与全因死亡率独立相关，但它可能对其他常规测量的预测指标（包括平均血压）的临床实用性增加有限。
