McDermott Mary McGrae, Liu Kiang, Greenland Philip, Guralnik Jack M, Criqui Michael H, Chan Cheeling, Pearce William H, Schneider Joseph R, Ferrucci Luigi, Celic Lillian, Taylor Lloyd M, Vonesh Ed, Martin Gary J, Clark Elizabeth
Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Ill, USA.
JAMA. 2004 Jul 28;292(4):453-61. doi: 10.1001/jama.292.4.453.
Among individuals with lower-extremity peripheral arterial disease (PAD), specific leg symptoms and the ankle brachial index (ABI) are cross-sectionally related to the degree of functional impairment. However, relations between these clinical characteristics and objectively measured functional decline are unknown.
To define whether PAD, ABI, and specific leg symptoms predict functional decline at 2-year follow-up.
DESIGN, SETTING, AND PARTICIPANTS: Prospective cohort study among 676 consecutively identified individuals (aged > or =55 years) with and without PAD (n = 417 and n = 259, respectively), with baseline functional assessments occurring between October 1, 1998, and January 31, 2000, and follow-up assessments scheduled 1 and 2 years thereafter. PAD was defined as ABI less than 0.90, and participants with PAD were categorized at baseline into 1 of 5 mutually exclusive symptom groups.
Mean annual changes in 6-minute walk performance and in usual-paced and fast-paced 4-m walking velocity, adjusted for age, sex, race, prior-year functioning, comorbid diseases, body mass index, pack-years of cigarette smoking, and patterns of missing data.
Lower baseline ABI values were associated with greater mean (95% confidence interval) annual decline in 6-minute walk performance (-73.0 [-142 to -4.2] ft for ABI <0.50 vs -58.8 [-83.5 to -34.0] ft for ABI 0.50 to <0.90 vs -12.6 [-40.3 to 15.1] ft for ABI 0.90-1.50, P =.02). Compared with participants without PAD, PAD participants with leg pain on exertion and rest at baseline had greater mean annual decline in 6-minute walk performance (-111 [-173 to -50.0] ft vs -8.67 [-36.9 to 19.5] ft, P =.004), usual-pace 4-meter walking velocity (-0.06 [-0.09 to -0.02] m/sec vs -0.01 (-0.03 to 0.003] m/sec, P =.02), and fastest-pace 4-meter walking velocity (-0.07 [-0.11 to -0.03] m/sec vs -0.02 [-0.04 to -0.006] m/sec, P =.046). Compared with participants without PAD, asymptomatic PAD was associated with greater mean annual decline in 6-minute walk performance (-76.8 (-135 to -18.6] ft vs -8.67 (-36.9 to 19.5] ft, P =.04) and an increased odds ratio for becoming unable to walk for 6 minutes continuously (3.63; 95% confidence interval, 1.58-8.36; P =.002).
Baseline ABI and the nature of leg symptoms predict the degree of functional decline at 2-year follow-up. Previously reported lack of worsening in claudication symptoms over time in patients with PAD may be more related to declining functional performance to than lack of disease progression.
在下肢外周动脉疾病（PAD）患者中，特定的腿部症状和踝臂指数（ABI）与功能损害程度存在横断面相关性。然而，这些临床特征与客观测量的功能下降之间的关系尚不清楚。
确定PAD、ABI和特定腿部症状是否能预测2年随访时的功能下降。
设计、设置和参与者：对676名连续纳入的有或无PAD的个体（年龄≥55岁，分别为417名和259名）进行前瞻性队列研究，基线功能评估于1998年10月1日至2000年1月31日进行，此后1年和2年安排随访评估。PAD定义为ABI小于0.90，基线时患有PAD的参与者被分为5个相互排斥的症状组之一。
6分钟步行表现、常速和快速4米步行速度的年均变化，并根据年龄、性别、种族、上一年功能、合并疾病、体重指数、吸烟包年数和缺失数据模式进行调整。
较低的基线ABI值与6分钟步行表现的更大平均（95%置信区间）年下降相关（ABI<0.50时为-73.0[-142至-4.2]英尺，ABI为0.50至<0.90时为-58.8[-83.5至-34.0]英尺，ABI为0.90-1.50时为-12.6[-40.3至15.1]英尺，P=0.02）。与无PAD的参与者相比，基线时运动和休息时均有腿痛的PAD参与者6分钟步行表现的平均年下降更大（-111[-173至-50.0]英尺对-8.67[-36.9至19.5]英尺，P=0.004），常速4米步行速度（-0.06[-0.09至-0.02]米/秒对-0.01[-0.03至0.003]米/秒，P=0.02），以及最快速度4米步行速度（-0.07[-0.11至-0.03]米/秒对-0.02[-0.04至-0.006]米/秒，P=0.046）。与无PAD的参与者相比，无症状PAD与6分钟步行表现的更大平均年下降相关（-76.8[-135至-18.6]英尺对-8.67[-36.9至19.5]英尺，P=0.04），以及连续6分钟无法行走的比值比增加（3.63；95%置信区间，1.58-8.36；P=0.002）。
基线ABI和腿部症状的性质可预测2年随访时的功能下降程度。先前报道的PAD患者间歇性跛行症状随时间未加重可能更多与功能表现下降有关，而非疾病无进展。
