Natural history of physical function in older men with intermittent claudication.

Purpose: This study was undertaken to determine the natural history of physical function in older men limited by intermittent claudication.

Methods: Forty-three men limited by intermittent claudication (mean age, 69 +/- 7 years) were recruited and followed up for 18 months. At baseline the patients reported a history of intermittent claudication for 6.1 +/- 6.1 years, and were able to walk for 1.9 +/- 1.6 blocks before experiencing claudication pain. Measurements during the 18-month study included ankle-brachial index (ABI), calf blood flow, 6-minute walk performance, monitored and self-reported physical activity, self-reported stability while walking, and summary performance score of physical function determined from a 4-m walk test, a chair stand test, and a tandem stand test.

Results: Pain-free walking distance during the 6-minute walk test decreased by 22% (P <.05) from baseline (185 +/- 96 m) to follow-up (144 +/- 93 m), and the total 6-minute walk distance decreased by 9% (P <.05), from 368 +/- 106 m to 334 +/- 90 m. Furthermore, monitored physical activity decreased by 31% (P <.05), from 159 +/- 151 kcal/d to 110 +/- 137 kcal/d; self-reported physical activity declined by 27% (P <.05), from 1.5 +/- 1.0 units to 1.1 +/- 0.8 units; tandem stance time declined by 14% (P <.05), from 9.46 +/- 1.83 seconds to 8.12 +/- 2.10 seconds; summary performance score of physical function decreased by 12% (P <.05), from 6.8 +/- 2.4 units to 6.0 +/- 2.4 units; and the percentage of patients reporting ambulatory unsteadiness and stumbling increased from 28% to 43% (P <.05). Calf blood flow measured at rest declined by 18% (P <.05), from 3.72 +/- 1.81 (mL/100 mL(-1)/min(-1)) to 3.04 +/- 1.43 mL/100 mL(-1)/min(-1), whereas ABI did not change (P >.05).

Conclusion: Older men limited by intermittent claudication experienced decline in ambulatory function, physical activity, physical function, stability, and calf blood flow over 18 months of follow-up, despite no change in ABI.