AUTONOMIC NEUROPATHY INFLUENCES GREAT TOE BLOOD-PRESSURE

OBJECTIVE - To assess the influence of autonomic neuropathy on toe blo od pressure (TBP), a parameter used currently as an ischemic index. RE SEARCH DESIGN AND METHODS - The age-matched study subjects included 20 non-insulin-dependent diabetes mellitus (NIDDM) patients with autonom ic neuropathy (DN) and 10 NIDDM patients without autonomic neuropathy (D), assessed by standard cardiovascular tests and galvanic skin respo nse, and 8 control subjects (C). None of the subjects had peripheral v ascular disease (PVD) (ankle/brachial index 0.9-1.1. RESULTS - The TBP and toe/brachial index (TBI) were significantly lower in DN than in C and D (P < 0.01). The saturation index (SI), the ratio between foot v enous and arterial partial pressure of oxygen (PO2), was significantly higher in DN than in C and D (P < 0.05). An inverse relationship was found between TBI and SI (r = 0.554, P = 0.001). CONCLUSIONS - The aut onomic nervous system directly influences peripheral circulation. In d iabetic patients without PVD, a failure of sympathetic fibers caused b y autonomic neuropathy could lead to a reduction of TBP. Therefore, TB P cannot be used as an ischemic index in diabetic patients.