Peripheral arterial occlusive disease (PAOD) is common in older age. PAOD is associated with an increased risk of vascular events (e. g.
myocardial infarction or
stroke). Therefore, the prevention and treatment of PAOD is important, especially at a time when the elderly population is increasing. There is an association between
lipid abnormalities and the risk of developing PAOD. However, it is not yet definitively established if early intervention with
lipid lowering drugs prevents the development of PAOD and improves outcome.
RESULTS OF STUDIES: In a 5-year follow-up study, in which
hypercholesterolemia was treated by partial ileal bypass (POSCH study), the incidence of claudication was reduced to 19% (n = 126) in the surgical treatment group vs. 33.6% (n = 119) in the control group (p < 0.01). Direct imaging of peripheral
atherosclerosis was not performed and a partial ileal bypass operation is followed by considerable changes in nutrition. A 2-year follow-up study of 153 patients with femoral
atherosclerosis treated with
colestipol-
niacin demonstrated a decreased progression of angiographically assessed femoral
atherosclerosis (p < 0.02). A subgroup analysis of the Scandinavian
Simvastatin Survival Study (n = 4,444) reported worsening symptoms in 3.6% in the placebo group as compared to 2.3% in the
simvastatin group (p = 0.008). In an open trial
lipid-lowering
therapy with
statins did not improve functional outcomes including 6 minutes walking distance and 4 minutes walking velocity in 392 men and women with an ankle-brachial-index (ABI) < 0.90. A summary performance score combined performance in walking speed, standing balance, and time for five repeated chair rises into an ordinal score ranging from 0 to 12 (12 = best) was improved (p < 0.001). A randomized placebo controlled prospective study with
simvastatin including 43 patients in each group demonstrated an improved painfree and total walking distance as well as an increased ABI after 6 months. A second placebo controlled study investigated the effect of 10 mg and 80 mg
atorvastatin in 354 patients after 12 months. Painfree walking time was only improved by 80 mg
atorvastatin, maximum walking time and ABI remained unchanged. A questionnaire regarding physical activity showed improved results already for 10 mg
atorvastatin, whereas quality of life did not change. Pathomechanistic explanations, such as regression of peripheral
atherosclerosis, were not described.
CONCLUSION: All in all the association between the progression of PAOD and
lipid abnormalities is surprisingly inconclusive and the effects of
lipid-lowering are not defined. Well designed long-term studies assessing primary and
secondary prevention of PAOD with defined endpoints, such as
amputation rate or number of vascular interventions are missing. The mechanisms improving physical activity whithout affecting PAOD outcome have to be investigated.