OBJECTIVE To evaluate whether plasma fibrinogen concentration is correlated with the level of physical activity and aerobic power in patients with newly diagnosed non-insulin-dependent diabetes mellitus (NIDDM).

RESEARCH DESIGN AND METHODS We studied 78 middle-aged (54 ± 6 years, mean ± SD), obese (body mass index [BMI] 32 ± 5 kg/m²) patients (45 men and 33 women) before and after a 12-month treatment period consisting of either conventional treatment given by community health centers or intensified dietary and exercise education given by a university outpatient clinic. Plasma fibrinogen concentration was measured by using a coagulometer. Physical activity was assessed by a questionnaire, and the patients were classified into a sedentary group or moderately or intensively exercising groups. Aerobic power (maximum oxygen uptake [], anaerobic threshold []) was measured by direct breath-by-breath technique.

RESULTS At baseline, the sedentary patients had higher fibrinogen concentration than those with moderate or high physical activities (3.8 ± 0.8 vs. 3.3 ± 0.7 g/I, P < 0.01). Both and (ml · min⁻¹ · kg⁻¹) showed an inverse linear correlation with fibrinogen (r = -0.38, P < 0.001, and r = -0.29, P < 0.01, respectively). In the step wise multiple regression analysis, BMI, Vo_{2 max} (ml/min), and smoking were the only significant independent factors explaining 23% of the variance in fibrinogen concentration. In sedentary patients, poor glycemie control was related with high fibrinogen concentration. During the follow-up period, patients maintained, on the average, good to moderate glycemie control. The originally sedentary group showed a decrease in fibrinogen concentration (to 3.3 ± 0.7 g/I, P < 0.001) that reached the same level that the physically more active groups had at baseline. This change was associated with improved glycemie control, but not with any of the other assessed factors, including fatty acid composition of serum lipids reflecting dietary intake of fats.

CONCLUSIONS In addition to BMI and smoking, low reported physical activity and low aerobic power are independently associated with high plasma fibrinogen concentration in newly diagnosed NIDDM.