Biomedical subjects

Masafumi Shirai

Publications and source records attributed to Masafumi Shirai.

9 recordsLinked to original sources

PubMed2005

Prevalence and risk factors for erectile dysfunction in Japanese diabetics.

We evaluated the prevalence and risk factors for erectile dysfunction (ED) and interest in ED treatment among Japanese men being treated for type 2 diabetes mellitus. Patients (40-79 years; n=1118) completed the 5-item version of the International Index of Erectile Function (IIEF-5), and questions related to interest in ED pharmacotherapy, subjective symptoms of diabetes, and general quality of life. A separate survey completed by physicians examined the relationships between age, diabetic treatments (insulin or oral), symptoms of diabetes (poor glycemic control, microangiopathy), complications of diabetes (hypertension, ischemic heart disease, cerebrovascular disease), and ED. The prevalence of ED in patients with diabetes was 90%, a rate double that of non-diabetic individuals. Multivariate analyses revealed that age, insulin therapy, microangiopathy, hypertension, history of cerebrovascular or cardiovascular disease, leg dysesthesia, dysuria, insomnia, and anorexia all represented significant risk factors for ED. Half of all respondents were interested (29%) or would consider pharmacotherapy for ED (21%). These findings suggest that ED is a significant problem in Japanese men with diabetes, and that specific risk factors increase the prevalence of ED. Furthermore, the survey results expose national attitudes toward treatment of ED.

Adult↗

PubMed2003

Epidemiology of erectile dysfunction in four countries: cross-national study of the prevalence and correlates of erectile dysfunction.

OBJECTIVES: To measure the prevalence of erectile dysfunction (ED) in community-based populations in Brazil, Italy, Japan, and Malaysia and to study its association with the demographic characteristics, medical conditions, and health-related behavior. METHODS: In each country, a random sample of approximately 600 men aged 40 to 70 years was interviewed using a standardized questionnaire. All the data were self-reported. ED was assessed by the participants' "ability to attain and maintain an erection satisfactory for sexual intercourse," and the men were classified as not having ED if they answered "always" and as having mild, moderate, or complete ED if they answered "usually," "sometimes," or "never," respectively. RESULTS: The age-adjusted prevalence of moderate or complete ED was 34% in Japan, 22% in Malaysia, 17% in Italy, and 15% in Brazil. The overall age-specific prevalence of moderate or complete ED was 9% for men aged 40 to 44 years, 12% for 45 to 49 years, 18% for 50 to 54 years, 29% for 55 to 59 years, 38% for 60 to 64 years, and 54% for those 65 to 70 years. The increased risk of ED was associated with diabetes, heart disease, lower urinary tract symptoms, heavy smoking, and depression and increased by 10% per year of age. It was inversely associated with education, physical activity, and alcohol drinking. CONCLUSIONS: ED is an international problem, the prevalence and severity of which increases with age. Despite national variations in prevalence, uniform associations were found between ED and medical conditions and lifestyle habits.

Adult↗

PubMed2002

Loss of anti-apoptotic genes in aging rat crura.

PURPOSE: Erectile dysfunction is a common problem in aging men. The molecular mechanisms associated with aging erectile dysfunction are not completely understood. We hypothesized that apoptosis is a downstream event in erectile dysfunction, and pro-apoptotic (Bak and Bax) and anti-apoptotic (Bcl-2 and Bcl-x) factors are involved in the etiology of aging erectile dysfunction. To test this hypothesis intracavernous pressure in aging rats was measured to assess erectile function. Gene and protein expression of pro-apoptotic and anti-apoptotic factors was then analyzed in aging rat crura to assess its role in aging erectile dysfunction. MATERIALS AND METHODS: A total of 25 male Sprague-Dawley rats divided into 5 groups of 5 each based on age (6, 12, 18, 24 and 28 months old, respectively) were used in functional and apoptotic studies. In addition, 5, 3-month-old male Sprague-Dawley rats were used in the apoptotic study. The rats were anesthetized with pentobarbital. Erectile function was assessed by measuring intracavernous pressure after electrostimulation of the cavernous nerves. After completion of the functional study the penile crura were immediately harvested for histochemical and molecular studies. Gene expression of pro-apoptotic (Bak and Bax) and anti-apoptotic (Bcl-2 and Bcl-x) factors were then analyzed by reverse transcription-polymerase chain reaction. Protein expressions of these apoptotic factors were also analyzed by immunohistochemistry using specific antibodies. RESULTS: Mean intracavernous pressure plus or minus SD in 18, 24 and 28-month-old rats was significantly lower than in 6-month-old rats (101.6 +/- 24.8, 77.7 +/- 24.5 and 45.7 +/- 7.3 versus 136.7 +/- 11.4 cm. water, respectively; p <0.05). The reduction in intracavernous pressure was an age dependent phenomenon. Gene and protein expression of the pro-apoptotic genes Bak and Bax was detected in the crura of all age groups but there was no significant difference in young and old rat crura. The anti-apoptotic Bcl-2 and Bcl-x genes were expressed in 3, 6 and 12-month-old crura, whereas this expression was lost at 18, 24 and 28 months. Anti-apoptotic Bcl-2 and Bcl-x proteins were also expressed in young rat crura, whereas this expression was lost in old rat crura. CONCLUSIONS: The decline in intracavernous pressure correlated significantly with a loss of anti-apoptotic genes in aging rat crura. To our knowledge this is the first report to show the loss of anti-apoptotic factors in aging rat crura and suggest their role in the pathogenesis of aging erectile dysfunction.

Aging↗

PubMed2002