Preliminary evidence that low ankle-brachial index is associated with reduced bilateral hip extensor strength and functional mobility in peripheral arterial disease

• Published in: Journal of vascular surgery 2013-04, Vol.57 (4), p.963-973.e1
• Main Authors: Parmenter, Belinda J., PhD, Raymond, Jacqueline, PhD, Dinnen, Paul J., MD, FRACS, Lusby, Robert J., MD, FRCS, FRACS, Fiatarone Singh, Maria A., MD
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Ankle Brachial Index; Biomechanical Phenomena; Cross-Sectional Studies; Exercise Test; Exercise Tolerance; Female; Hip Joint - physiopathology; Humans; Intermittent Claudication - etiology; Intermittent Claudication - physiopathology; Linear Models; Male; Middle Aged; Muscle Strength; Muscle, Skeletal - physiopathology; Muscular Atrophy - etiology; Muscular Atrophy - physiopathology; New South Wales; Peripheral Arterial Disease - complications; Peripheral Arterial Disease - diagnosis; Peripheral Arterial Disease - physiopathology; Pilot Projects; Predictive Value of Tests; Risk Factors; Severity of Illness Index; Surgery; Walking
• ISSN: 0741-5214; 1097-6809
• DOI: 10.1016/j.jvs.2012.08.103

Objective Peripheral arterial disease (PAD) has been associated with skeletal muscle pathology, including atrophy of the affected muscles. In addition, oxidative metabolism is impaired, muscle function is reduced, and gait and mobility are restricted. We hypothesized that greater severity of symptomatic PAD would be associated with lower levels of muscle mass, strength, and endurance, and that these musculoskeletal abnormalities in turn would impair functional performance and walking ability in patients with PAD. Methods We assessed 22 persons with intermittent claudication from PAD in this cross-sectional pilot study. Outcome assessments included initial claudication distance and absolute claudication distance via treadmill protocols and outcomes from the 6-minute walk (6MW). Secondary outcomes included one repetition maximum strength/endurance testing of hip extensors, hip abductors, quadriceps, hamstrings, plantar flexors, pectoral, and upper back muscle groups, as well as performance-based tests of function. Univariate and stepwise multiple regression models were constructed to evaluate relationships and are presented. Results Twenty-two participants (63.6% male; mean [standard deviation] age, 73.6 [8.2] years; range, 55-85 years) were studied. Mean (standard deviation) resting ankle-brachial index (ABI) was 0.54 ([0.13]; range, 0.28-0.82), and participants ranged from having mild claudication to rest pain. Lower resting ABI was significantly associated with reduced bilateral hip extensor strength (r = 0.54; P  = .007) and reduced whole body strength (r = 0.32; P  = .05). In addition, lower ABI was associated with a shorter distance to first stop during the 6MW (r = 0.38; P  = .05) and poorer single leg balance (r = 0.44; P  = .03). Reduced bilateral hip extensor strength was also significantly associated with functional outcomes, including reduced 6MW distance to first stop (r = 0.74; P  = .001), reduced 6MW distance (r = 0.75; P