Key words: Type 2 diabetes mellitus, thermography, arteriosclerosis, sympathetic nerve .... determined (N=4). We excluded Monckeberg sclerosis in our patients,.
Exp Clin Endocrinol Diabetes 108 (2000) 463 ± 469
Experimental and Clinical
Endocrinology & Diabetes 2000 Johann Ambrosius Barth
Thermographic measurement of skin temperature recovery time of extremities in patients with type 2 diabetes mellitus Y. Fujiwara, T. Inukai, Y. Aso, Y. Takemura Department of Medicine, Koshigaya Hospital, Dokkyo University School of Medicine, Koshigaya, Japan Key words: Type 2 diabetes mellitus, thermography, arteriosclerosis, sympathetic nerve function, blood-coagulation-fibrinolytic system Summary: To elucidate the relationship between the recovery of skin temperature in an extremity after exposure to cold water and various factors associated with diabetes, we measured skin temperature in type 2 diabetic patients (N = 61) and control subjects (N= 16). A thermo-tracer was used in thermographic measurements. The right third toe of each subject was immersed in cold water at 08C for 10 sec. Rt represents the recovery rate of skin temperature at t min after exposure. Rt was significantly reduced in the diabetic patients every 5 min in the 20 min period following exposure compared with control subjects. The diabetic patients group exhibited a significantly positive correlation between R20
Introduction The presence of complications of diabetes mellitus is important in determining the prognosis. Diabetic gangrene and/or leg ulcers may ultimately require amputation of the affected limb, which lowers the patients quality of life (Boulton et al., 1982; Coleman and Brand, 1997). The pathogenesis of these complications is supposed to involve a reduction in skin blood flow, mainly due to the autonomic neuropathy associated with diabetes (Armstrong et al., 1997; Haak E et al., 1998; Abbott et al., 1998). This neuropathy causes a dilatation of the arteriovenous anastomosis and reduces the blood supply to the capillaries due to the steal phenomenon (Boulton et al., 1982). Such factors as vascularization, the somatic nervous system, and blood coagulation system have been suggested to be involved in the reduced circulation of the skin (Habler et al., 1998). Thermography shows the distribution of skin temperature in images, thus demonstrating visually the condition of the circulation. Skin thermography following exposure to cold water is useful in the quantitative evaluation of disorder of the peripheral sympathetic nervous system and of the peripheral circulation (Fushimi et al., 1996; Bruehl et al., 1996). The present study used thermography to evaluate skin blood flow in diabetic patients before and after
and the ankle-brachial index. R20 in the diabetic patients showed a significantly positive correlation with the reduction in systolic blood pressure at the arm observed in Schellong s test. In addition, R20 showed a significantly negative correlation with plasma levels of fibrinogen and plasminogen activator inhibitor-1. However, the severity of diabetic retinopathy and nephropathy was not significantly related to R20 in the diabetic patients. The present data indicate that the recovery of skin temperature after immersion in cold water was markedly reduced in patients with type 2 diabetes mellitus as compared with healthy control subjects. Peripheral arteriosclerosis, impaired sympathetic nerve function and the activation of the blood coagulation system may all contribute to this reduced recovery of skin temperature.
immersion of the leg in cold water. The complicating relationship between the skin temperature recovery rates and various factors was examined, including diabetic retinopathy and nephropathy.
Materials and methods Study population Studies were conducted in 61 Japanese patients with type 2 diabetes: 32 men and 29 women, mean age 58.58.4 years, and 16 healthy subjects: 5 men and 11 women, mean age 57.91.5 years. Type 2 diabetes was defined as diabetic patients with neither glutamic acid decarboxylase antibody (GADAb) nor islet cell antibody (ICA) and without the history of ketoacidosis or absolute insulin deficiency. The age-matched healthy subjects served as controls. The mean known diabetes duration was 8.8 5.5 years. In the patients, the fasting plasma glucose level was 136.2 41.5 mg/ dl, HbA1c was 9.11.8% and body mass index (BMI) was 23.9 3.1 kg/m2. The diabetic patients were receiving dietary therapy (N=6), oral hypoglycemic agents (N=25), or insulin therapy (N=30). The severity of diabetic retinopathy was classified as follows: no diabetic retinopathy (N=25), simple diabetic retinopathy (N= 12), proliferative diabetic
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retinopathy (N=16) and not determined (N=8). Simple diabetic retinopathy was defined as a change in retina with soft or hard white spots, proliferative diabetic retinopathy was as a change in retina with newly synthesized vessels. Diabetic nephropathy was classified according to urinary albumin excretion (UAE) corrected by urinary creatinine (Cr.) levels. The former was determined by enzymeimmunoassay (EIA) (Feld-Rasmussen et al., 1985). Patients exhibited were normoalbuminuria (NAU) with UAE less than 30 mg/g.Cr. (N = 20), microalbuminuria (MiAU), with UAE in the range of 30 ±200 mg/ g.Cr. (N = 15), macroalbuminuria (MaAU), with UAE more than 200 mg/g.Cr. (N = 22) and not determined (N=4). We excluded Monckeberg sclerosis in our patients, by considering clinical symptoms represented in Fontaine s classification and by checking calcifications of vessels on X-ray pictures in lower extremities. We withdrew the drug treatment affecting mocrocirculation in some diabetic patients during the present study.
As a marker of sympathetic nerve function, we conducted Schellong s test after the blood pressure had stabilized with the subject supine. The subject then stood up, and we continuously measured the blood pressure every min for 10 min. The lowest systolic blood pressure was determined. The change in systolic blood pressure was calculated as the difference between the lowest systolic blood pressure responded in standing position and the average of systolic blood pressure recorded in the supine position. As markers of the blood coagulation-fibrinolytic system, the plasma level of fibrinogen was measured by photo-dispersion method. Plasma levels of plasminogen activator inhibitor-1 (PAI-1) (Declerck et al., 1988), thrombomodulin (TM) (Ishii et al., 1990), and thrombin-antithrombin III complex (TAT) were assayed by enzymeimmunoassays. The coefficients of variation in my methods for the determination of these three markers were 6.7%, 5.9% and 7.8%, respectively.
Methods
Statistical analysis
The thermography was performed under controlled environmental conditions: ambient temperature, 24 18C and humidity 605%. We used the thermotracer TH-3108 (NEC, Japan), a medical thermographic device (Fushimi et al., 1996; Bruel et al., 1996). After the patient had adapted to indoor conditions for 20 minutes, the right leg was immersed in cold water 0 8C for 10 sec. Thermographic measurements were made on the metatarsophalangeal joint of the third toe. The skin temperature could be determined on the display in a computer by adjusting a cursor on the measuring-position. Measurements were made at 10 and 5 min before the exposure to cold water and again at 0, 5, 10, 15 and 20 min afterwards. The recovery rate of skin temperature at t min (Rt) was calculated as follows.
Data were presented as mean SD. Comparison between groups utilized one-way ANOVA with Neuman-Keuls multiple comparison test. The correlation between two parameters was examined by linear-regression analysis with parametric or nonparametric tests. A level of P
