In order to investigate the effect of cold circumstances on hypertension and its complications, this epidemiologic study, prospectively to cover a ten year period, was started in 1977 on 996 subjects in the relatively cold town of“Tanno”, T-Cho, and on 1000 subjects in the relatively warm town of“Sobetsu”, S-Cho, in Hokkaido, Japan, who range in age from 40 to 64. Measurements of blood pressure, height, body weight, the index of obesity and skinfold thickness, laboratory tests of blood and the gulcose tolerance test have been performed in the early morning following overnigth fasting. The results of this study in the first year were as follows. 1) Participant rates in T-Cho and S-Cho were 99.7 and 99.8%, respectively. 2) Systolic blood pressure, β-lipoprotein and blood urea nitrogen in the summer in T-Cho, and systolic and diastolic blood pressure in the winter and the index of obesity, skinfold thickness, total cholesterol, total protein, fasting blood sugar and the cardio-thoracic ratio in the summer in S-Cho were significantly higher when compared with results in the other town. 3) Incidences of hypertension and borderline hypertension defined by the criteria of WHO were 21.3 and 19.9%, respectively, (total 41.2%) in T-Cho and 24.3 and 15.7%, respectively, (total 40.0%) in S-Cho in the summer, and 20.2 and 21.6%, respectively, (total 41.8%) in T-Cho and 28.1 and 16.6%, respectively, (total 44.7%) in S-Cho in the winter. 4) The prevalence rate of hypertension obviously increased with age in both towns. 5) The greatest range of individual blood pressure was 120-129mmHg in systole and 80-89mmHg in diastole in both towns. 6) The mean value of blood pressure, and the incidence of hypertension and borderline hypertension in T-Cho were almost equal between the summer and the winter, whereas those in S-Cho increased in the winter. 7) Cases in which over 20% was observed on the index of obesity were noted in 23.5% of the subjects in T-Cho and 28.8% of those in S-Cho. 8) Incidences of cases with≥231mg/dl in total cholesterol, ≥451mg/dl in β-lipoprotein, ≥171mg/dl and≤70mg/dl in triglyceride, ≥21mg/dl in blood urea nitrogen and≥7.0mg/dl in uric acid were 11.2, 27.7, 14.0, 27.4, 13.8 and 12.3% in T-Cho and 13.3 19.6, 14.3, 14.9, 8.4 and 12.0% in S-Cho, respectively. 9) 45.1% of the subjects in T-Cho and 56.3% in S-Cho showed an abnormal glucose tolerance, and these incidences increased with age. However, most abnormalities remained of borderline type. 10) The incidences of cases with a cardio-thoracic ratio of more than 50% and with abnormal electrocardiograms were 27.3 and 31.1%, respectively, in T-Cho and 36.6 and 31.7%, respectively, in S-Cho.
In 7 normostensive elderly persons aged 69-83 years and 5 normotensive juvenile persons aged 23-31 years, the heart rates, blood pressure and plasma catecholamines before and after a bathing for 10min. in the Harvard bath were followed up in the time course. Both the elderly group and the juvenile group showed a significant increase in the heart rate during a bathing at 42°C, and this change was significantly greater than that during a bathing at 38°C. Also, at both temperature, the juvenile group showed significantly greater changes than the elderly group. Although both groups showed significant decreases in mean blood pressure during a bathing at both temperature, those degrees showed no difference due to water temperature and age. Also the elevation of mean blood pressure accompanying the leave from a bath was significant at 38°C in both groups. The values of plasma norepinephrine decrease slightly during a bathing in both of the juvenile and elderly groups, and rose after leaving from the bath. Such variations showed significantly positive correlations with variations in mean blood pressure. The decrease of blood pressure accompanying the bathing seemed to be accompanied with an inhibition of the sympathetic activity.
Thirty-two cases of congenital numeral anomalies of the semilunar valves were found among a total of 3, 000 consecutive autopsy of the aged more than 60 years, with an incidence of 1.06%. These consisted of 10 cases of bicuspid aortic valve (0.33%), 3 cases of quadricuspid aortic valve (0.1%), 2 cases of bicuspid pulmonic valve (0.07%) and 17 cases of quadricuspid pulmonic valve (0.5%). Calcified aortic stenosis developed in 7 out of 10 cases of bicuspid aortic valve. There were 8 cases in whom each coronary artery originated from each coronary sinus, and 2 cases in whom both coronary arteries originated from a coronary sinus. Three cases of quadricuspid aortic valve were not clinically diagnosed, and the 4th cusp was the smallest one, which was located between the right and the non-coronary cusps. One of 2 cases of bicuspid pulmonic valve showed diastolic murmur at the left sternal border, starting with the pulmonic component of the 2nd heart sound, which was considered to be pulmonic regurgitation. Morphologically union of the left and the right cusps was shown. Quadricuspid pulmonic valve showed the highest incidence, but clinical diagnosis was not made despite of cardiac murmurs in 9 cases. Morphologically 4 cusps of the quadricuspid valve were of the same size in 3 cases, and in 14 cases the 4th cusp was the smallest one, which was located between the right and the left cusps in 6, between the left and the antrior cusps in 7, and between the anterior and the right cusps in 1 case.