Koichi Shido

A Case-Control Study of Alzheimer's Disease in Japan – Significance of Life-Styles

A case-control study of Alzheimers disease was conducted in Japan; it involved 60 cases matched for sex and age with two resident controls each. Life-style was particularly highlighted in this study. Among many factors, 5 were accepted as significant risk factors: psychosocial inactivity, physical inactivity, head injury, loss of teeth and low education. A multiple logistic model was applied in order to evaluate synergism of major factors. Compared with those who have none of the factors, those who have all were 934.5 times more liable to develop Alzheimers disease. Risk factors are not only useful for etiological studies but they give clues to identify high-risk individuals, and by eliminating these factors, the studies may also be applicable in the primary and the secondary prevention of this tragic disease.

Angiotensin converting enzyme as a genetic risk factor for coronary artery spasm. Implication in the pathogenesis of myocardial infarction.

It has been reported that individuals with the D allele of an insertion/deletion (I/D) polymorphism of the angiotensin converting enzyme (ACE) gene are at greater risk for myocardial infarction (MI), especially among subjects normally considered to be at low risk. However, little is known about the mechanism by which the ACE polymorphism affects the risk of MI. Coronary artery spasm (CAS) is considered to be one possible mechanism for developing MI. We therefore examined the ACE polymorphism relation to CAS to determine if this was the mechanism by which the DD genotype influences MI. We studied 150 angiographically assessed Japanese males, all more than 60 yr old. CASs were detected using intracoronary injection of ergonovine maleate. Subjects were divided into three groups: those with CAS (group 1), those without CAS, but with fixed organic stenosis (group 2); and those without CAS and no organic stenosis (group 3). DD subjects were significantly represented in group 1 when compared with groups 2 (P = 0.002) and 3 (P = 0.026). These results suggest that the DD genotype relates to the greater risk for MI in the patients with CAS.

Association of a variant of the angiotensinogen gene with pure type of hypertension in pregnancy in the Japanese: Implication of a racial difference and significance of an age factor

The contribution of genetic factors to hypertension in pregnancy, including pre-eclampsia, has been well documented. The association with a common molecular variant of the angiotensinogen (AGT) gene, in which methionine (M235) is substituted for threonine (T235) at residue 235, has been reported in both Caucasians and Japanese. In the present study, we examined 115 cases of pure type of hypertension in pregnancy (PHP) and 381 normal pregnant controls in order to look for subgroups in which the AGT gene is the major factor in the PHP pathogenesis. By classification of PHP cases according to the clinical diagnosis, gravidity, and maternal age, we found significantly higher frequencies of T235 in both all PHP patients and preeclampsia/eclampsia patients than in normal controls. These results are discordant with those reported for Caucasian subjects where only a group of preeclamptic primigravidae was associated with the AGT variant, possibly indicating the existence of a racial difference. We also found that the variant frequency was significantly higher in the PHP subgroup with maternal age of 20-34 years (0.93) than in a subgroup of multigravid PHP patients age 35 years or older (0.77, P < 0.05) or in normal controls of age 20-34 years (0.76, P < 0.001). The result indicates that the AGT variant plays a significant role in hypertension in the age group 20-34 years.

Risk Factors of Senile Dementias: Comparisons of Alzheimer’s Disease and Vascular Dementias

Diseases in old age affect organs which normally function for most of life. They clinically manifest themselves after a longstanding process influenced by cumulated effects of many genes and environmental factors, each with relatively minor contributions. In the present study, vascular dementias (VD) and Alzheimer’s disease (AD) were analyzed in an identical method in an attempt to compare the risk factors of the two major dementing diseases in old age.