Toshiro Yanai

Intracerebral hemorrhage in a Japanese community, Hisayama: incidence, changing pattern during long-term follow-up, and related factors.

The incidence of intracerebral hemorrhage over 13 years is compared between two Hisayama cohorts. Among men aged 40 years or older, the annual incidence declined significantly from 3.1/1,000 in the early cohort (1961-1970) to 1.2/1,000 in the recent cohort (1974-1983). Massive ganglionic hemorrhage decreased, while small or medium-sized intracerebral hemorrhage increased in the recent cohort on pathologic or computed tomographic examination. These trends could be due to the reduced prevalence of hypertension in the Hisayama population. The association of serum total cholesterol with intracerebral hemorrhage is discussed based on the results during a 22-year follow-up period.

Accuracy of diagnosis on death certificates for underlying causes of death in a long-term autopsy-based population study in Hisayama, Japan; with special reference to cardiovascular diseases.

Major categorical diagnosis by International Classification of Diseases and type-specific diagnosis for cardiovascular diseases in death certificates were compared to the diagnosis made at autopsy in 864 consecutive autopsy cases aged 20 or over, among the Japanese residents in Hisayama town. Cerebral stroke was correctly diagnosed in 84%, malignant neoplasms in 78% and cardiac disease in 66%. Cerebral stroke and cardiac disease tended to be overdiagnosed, while malignant neoplasms were underdiagnosed. The validation of certified diagnosis was less reliable in the aged population, and in type-specific diagnosis of cardiovascular diseases. Cerebral hemorrhage with false negative or false positive diagnoses was usually classified into type unspecified stroke or different categories of cerebral stroke, while those misdiagnosed as cases of cerebral infarction frequently had no significant lesions in the autopsied brain. Finally, the relationship between the validation of diagnosis on the death certificates and the secular trend in cardiovascular disease in the Japanese vital statistics was discussed.

Hematocrit as a risk factor of cerebral infarction: long-term prospective population survey in a Japanese rural community.

To elucidate the relation of hematocrit (Hct) to the incidence of cerebral infarction, a prospective follow-up study of 16 years (1965-81) was performed in a general population sample of 1220 Hisayama residents aged 44 and over, of both sexes. Most of the subjects who died during the follow-up period were autopsied, the rate being 89.0%. Hct decreased with advancing age in men, but not in women. The average value for Hct was significantly lower in women than in men. According to the mean value +/- 1 SD of Hct, the subjects were grouped into 3, in each sex as follows: low (less than 35%), normal (35-45%) and high (greater than or equal to 45%) for men, and, low (less than 30%), normal (30-40%) and high (greater than or equal to 40%) for women. During the follow-up period, cerebral infarction occurred in 117 patients. The cumulative incidence of cerebral infarction in the low Hct group for men was the lowest, even after adjustments for age and blood pressure. Conversely, the incidence in the low Hct group of women was significantly higher than that in the normal Hct group and was consistently increased with time during 2-5 years of the follow-up. After the 6th year or later, however, the incidence was gradually but significantly increased in the high Hct group, compared with the normal Hct group. Since Hct levels were related with other variables such as serum total cholesterol, serum total protein, Quetelet index and prevalence of hypertension in both sexes, heavy alcohol consumption in men, and glucose intolerance in women, such variables were taken into account using Coxs proportional hazards regression model.(ABSTRACT TRUNCATED AT 250 WORDS)

Transient cerebral ischemic attacks in a Japanese community, Hisayama, Japan.

During a 20-year follow-up of 1,621 men and women aged 40 and over in Hisayama, Japan, 18 were found to have suffered transient cerebral ischemic attacks (TIAs) determined by clinical symptoms based on criteria proposed by the US Joint Committee for Stroke Facilities. The average annual incidence rate for the first TIA was 0.56 per 1,000 residents. Age and high blood pressure were strong determinants of TIAs for men. Nine of the 18 cases with TIAs (50%) subsequently developed cerebral infarction, an incidence significantly higher than that in the 1,603 subjects without TIAs (10.9%). Lacunar infarcts were most commonly found on pathologic examination of patients with TIAs who had had a subsequent stroke.

Severe disability related to cerebral stroke: incidence and risk factors observed in a Japanese community, Hisayama.

To elucidate the incidence of severe disability due to cerebral stroke and its related factors, prospective data of 1,621 Hisayama residents aged 40 and over were examined. Severe disability resulting from stroke was defined as patients who were unable to dress, take care of their toilet needs, and feed themselves without assistance, or who required a wheel chair for ambulation three months after the most recent episode.

Effects of interferon on circadian changes in blood pressure and heart rate variability in patients with chronic hepatitis

We have determined the effects of interferon therapy on circadian changes in blood pressure and heart rate variability in normotensive hospitalized patients with chronic active hepatitis. Body temperature and pulse rate increased for the initial few days of interferon therapy without significant change in casual or ambulatory blood pressure. Interferon therapy failed to elicit any significant changes in the power spectrum of R-R intervals. In addition, urinary excretion of norepinephrine did not differ between before and during the therapy. These results suggest that interferon therapy caused transient increases in body temperature and pulse rate, but that it did not change either sympathetic or parasympathetic outflow, or the circadian rhythm of blood pressure and heart rate variability, in normotensive subjects.

Natural history of borderline hypertension in the hisayama community, Japan—I. The relative prognostic importance of transient variability in blood pressure

Long-term prognosis of borderline hypertensives was studied in a prospective population survey carried on since 1961 in the town of Hisayama, Japan. Five consecutive BP recordings on 1621 subjects aged 40 and over were obtained at entry, and the variability in BP between the first and fifth readings was taken into account when classifying the subject into categorical groups. Even with an estimated variability in BP in several measurements on one occasion, a large fluctuation in BP was observed in both the borderline hypertensives and the normotensives. Borderline hypertensives with a transient elevation in BP more frequently died from cardiovascular disease than did those without BP elevation, as estimated by the long-term cumulative mortality. However, there was no difference in the frequency of hypertension-related organ damage between these two groups at entry.