Effect of regular aerobic exercise on cerebrovascular tone in young women.

Our objective was to evaluate the effect of regular aerobic exercise on cerebrovascular tone in young women. Color and pulsed Doppler ultrasonography were used to determine the pulsatility index in the ophthalmic artery in 20 normotensive, nonpregnant young women (aged 19 to 26 years) with a regular menstrual cycle on cycle day 5. Blood pressure and heart rate were recorded at each examination. Blood samples were collected from all the subjects to measure serum estradiol levels and serum lipid profiles. Ten of the 20 women (exercise group) have maintained aerobic exercise for 50 min, 3 to 5 days a week, for at least a year. The other 10 women (nonexercise group) never did regular exercise. There were no significant differences between the two groups regarding age, body mass index, mean blood pressure, and heart rate and serum estradiol, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglyceride levels. The pulsatility index value (mean, 1.89; standard deviation, 0.33) of the ophthalmic artery in the exercise group was significantly lower than that (mean, 2.53; standard deviation, 0.26) in the nonexercise group. Regular aerobic exercise in young women significantly decreases the peripheral cerebrovascular tone, and this might be a favorable adaptation for early prevention of cerebrovascular disease, which is common in older women.

[Classification of asymptomatic autoimmune thyroiditis by thyrotropin-releasing hormone loading].

Thyrotropin-releasing hormone loading was performed on 91 patients with asymptomatic autoimmune thyroiditis. Four women had no response to this loading test and had high levels in serum total and free thyroxine (TT4, FT4) and in serum total and free triiodothyronine (TT3, FT3). These patients might be classified as subclinical hyperthyroidism (Group G). Twenty-four patients had normal levels of both basal and peak thyrotropin after loading and were classified as Group I. There were no significant differences between 45 controls (Group C) and Group I patients in serum thyroid hormone levels. Patients with normal basal and high peak levels of thyrotropin were included in Group II. The number of patients in this group was 53. The mean levels of basal and peak thyrotropin were 4.8 microU/ml and 39.6 microU/ml, respectively, and were significantly higher than in Group C and Group I (P less than 0.005). In 10 patients classified as Group III with high levels of both basal and peak thyrotropin, serum concentrations of TT4, FT4 and FT3 were significantly lower than in the other groups (P less than 0.025); however, significant differences in TT3 could not be seen among them. Serum cholesterol levels gradually increased from Group C to Group III. There were significant differences between Group C and Group II (P less than 0.05).