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Biomedical subjects

G S Jónsson

Publications and source records attributed to G S Jónsson.

2 recordsLinked to original sources

Lower extremity blood flow in healthy men: effect of smoking, cholesterol, and physical activity--a Doppler study.

Tobacco smoking is one of the principal risk factors of peripheral arterial disease (PAD); cholesterol level has a lesser impact. The effect of leisure-time physical activity (LTPA) has not been studied in depth. The aim of this study was to determine the relative effects of smoking, total cholesterol, and leisure-time physical activity on blood flow parameters in the lower extremities of healthy middle-aged men with no prior symptoms or diagnosis of PAD. The authors examined 130 men, aged 40-65 years, free of known arterial disease and hypertension. The men had either a total cholesterol concentration of < 5.7 or > 7.0 mmol/L, and were either smokers or nonsmokers. LTPA was addressed by a questionnaire. Ankle-brachial index (ABI) was calculated and Doppler examination of the femoral artery was performed before and after an exercise test. Tobacco smoking related significantly to abnormal ABI and Doppler results (odds ratio [OR] 2.42) while the total cholesterol level did not. LTPA had a favorable effect (OR 0.51). Abnormal ABI response was greatest in smokers with high total cholesterol (p < 0.01). Tobacco smoking is a significant risk factor for abnormal ABI response and blood flow abnormalities in healthy men. Regular physical activity has a measurable protective effect. An abnormal ABI suggests early atherosclerosis and indicates risk factor assessment and physician intervention.

Aged↗

Functional study of the dermal microcirculation in systemic sclerosis.

To measure the effect of cooling on digital blood pressure we used a strain-gauge and photoplethysmograph, with an automatic cooling device. Eighteen patients were compared with 18 matched controls. Laser-doppler technique was used to measure the perfusion changes after heating a small area of the skin in 5 locations on the body, readings were given in perfusion units. Eighteen patients with systemic sclerosis were compared with 25 individuals with primary Raynaud's phenomenon and 30 healthy controls. Cooling to 10 degrees C caused a significant digital blood pressure drop of 58 mmHg in patients with systemic sclerosis and 61 mmHg in Raynaud's phenomenon, as compared with controls. The microcirculation in patients with systemic sclerosis responded in the same way to local heating as in the normal population, increasing the perfusion to the same extent. In conclusion, an unselected group of patients with systemic sclerosis have normal dermal microcirculatory response to heating in spite of severe cold intolerance.

Adaptation, Physiological↗