Segmental blood flow and rheological determinants in diabetic patients with peripheral occlusive arterial disease Jacqueline Eleanor Vigilance 4 , Harvey L. Reid Department of Basic Medical Sciences, Physiology Section, University of the West Indies, Mona, Kingston 7, Jamaica Received 2 October 2006; accepted 7 November 2006 Abstract Vascular abnormalities are more prevalent in the lower extremities in diabetic patients and may cause diminished perfusion to surrounding tissues. We sought to identify blood flow abnormalities in the leg of diabetic patients with peripheral occlusive arterial disease (POAD) and to determine whether these were associated with abnormalities in rheological determinants, namely, plasma fibrinogen concentration (PFC), relative plasma viscosity (RPV), hematocrit (Hct), and whole blood viscosity (WBV). Seventeen diabetic patients with POAD were compared with 40 diabetic patients without POAD and 19 nondiabetic control subjects. Blood flow was measured by venous occlusion plethysmography, RPV was measured by capillary viscometry, WBV was measured by a Wells–Brooksfield viscometer [at high (230 s À1 ) and low (23 s À1 ) shear rates], and PFC was measured by the clot–weight method of Ingram [Ingram, G. I. C. (1961). A suggested schedule for the rapid investigation of acute haemostatic failure. Journal of Clinical Pathology, 14 , 356–360]. Ankle blood flow ( Q ak ) was significantly lower in diabetic patients with POAD than in diabetic patients without POAD ( Pb.05). PFC was higher and Hct was lower in diabetic patients with POAD than in diabetic patients without POAD ( Pb.05). RPV was 1.97F0.15 versus 1.92F0.15 in diabetic patients with POAD and diabetic patients without POAD, respectively ( PN .05). There was no significant difference in WBV at low or high shear rates between the groups studied. There was a correlation between WBV at low shear rate and arterial flow in the calf ( Q c )(r =.94) and great toe (r =.95) in diabetic patients with POAD, and between Q c and WBV at high (r =À.465) and low (r =À.472) shear rates in diabetic patients without POAD ( Pb.05). We conclude that vasodilatation occurring in diabetic patients without POAD is severely restricted or absent in diabetic patients with POAD. Increased plasma fibrinogen and plasma viscosity may contribute to this phenomenon. D 2008 Elsevier Inc. All rights reserved. Keywords: Peripheral occlusive arterial disease; Diabetes mellitus; Blood flow; Fibrinogen; Viscosity 1. Introduction Peripheral occlusive arterial disease (POAD) occurs with increasing frequency in the diabetic population (Osmundson et al., 1990). Studies have shown the prevalence of POAD [ankle–brachial systolic pressure index (ABI) b0.9] among a predominantly black Jamaican diabetic population to be between 14% (in the absence of any foot lesion) (Richards- George, 1990) and 22.4% (Vigilance, Reid, & Richard- George, 1999). The prevalence of POAD in a Caucasian diabetic patient population was 20% in the N40-year age group (Elhadd, Robb, Jung, Stonebridge, & Belch, 1999). Another survey of patients with diabetes who are N50 years of age showed a 29% prevalence of peripheral arterial disease (Hirsch et al., 2001). Maturity-onset diabetic foot ischemia is usually due to severe arteriosclerosis (Rao, Hanchard, Richards-George, Golding, & Richards, 1979). Several investigators have shown whole blood and plasma viscosity to be increased in patients with POAD (Forconi et al., 1979; Hung, Pham, Steed, Webster, & Butter, 1991). Whereas atherosclerotic lesions of peripheral arterial disease are focal and proximal in some high-risk patients, the lesions are likely to be more diffuse and distal in diabetic patients (American Diabetes Association, 2003). In fact, diabetes and diabetes-induced dyslipidemia may contribute 1056-8727/08/$ – see front matter D 2008 Elsevier Inc. All rights reserved. doi:10.1016/j.jdiacomp.2006.11.001 4 Corresponding author. E-mail address: jevigil1@yahoo.com (J.E. Vigilance). Journal of Diabetes and Its Complications 22 (2008) 210 – 216