Masayo Kojima

Epidemiological features of Moyamoya disease in Japan: findings from a nationwide survey

To estimate an annual number of patients treated for Moyamoya disease in Japan and to describe the clinico-epidemiological features, a nationwide epidemiological survey was conducted in 1995. The study consisted of two questionnaires, which were distributed to departments randomly selected, of neurosurgery, neurology and pediatrics in hospitals throughout Japan. The first questionnaire inquired the number of the patients treated in 1994 and the second one detailed clinico-epidemiological information of each patient reported. Following major epidemiological findings emerged from the study: (a) The total annual number of patients treated for Moyamoya disease was estimated as 3900 (95% confidence interval (CI) 3500-4400) in Japan 1994, with the prevalence and incidence rates of 3.16 and 0.35 per 100,000 population, respectively; (b) the sex ratio (females to males) of the patients was 1.8; (c) the peak of age distribution of the patients was observed in 10-14 years old and a smaller peak in their forties; (d) the age at onset was under 10 years old in 47.8% of the patients, but some had developed the disease at the age of 25-49 years; (e) family history of Moyamoya disease was found in 10.0% of the patients; and (f) about 75% of the patients had normal activity of daily life or working ability even before treatment. The present findings were quite comparable with those obtained in the previous nationwide epidemiological survey in 1990.

Nationwide epidemiological survey of chronic pancreatitis in Japan.

Abstract: The aim of this study was to estimate the number of patients treated for chronic pancreatitis in 1994 in Japan and to explore the clinico-epidemiological features of chronic pancreatitis. Two surveys were conducted. Stratified random sampling was used to select departments in which patients with chronic pancreatitis were treated, and two different questionnaires were administered to obtain relevant information. From the first survey, the total number of patients treated for chronic pancreatitis in Japan in the year 1994 was estimated as 32 000 (95% confidence interval, 25 000–39 000). Clinico-epidemiological features, based on the 2523 patients reported from the second survey, were subsequently clarified. The sex ratio (male/female) of the patients was 3.5. Alcoholic pancreatitis was the most common type in males (68.5%), and idiopathic pancreatitis in females (69.6%). Compared with the findings in the last survey in 1985, the proportion of patients with alcoholic pancreatitis has decreased slightly, from 58.7% to 55.5%, while that of idiopathic chronic pancreatitis has increased in both males and females. Patients diagnosed by advanced techniques such as computed tomography (CT) and endoscopic retrograde cholangiopancreatography (ERCP) accounted for 68.1% of the total. The number of patients with chronic pancreatitis treated in 1994 in Japan, was estimated as 32 000, with an overall prevalence rate of 45.4 per 100 000 population in males and 12.4 per 100 000 population in females.

Prevalence and Renal Prognosis of Diagnosed Autosomal Dominant Polycystic Kidney Disease in Japan

The prevalence and renal prognosis of diagnosed autosomal dominant polycystic kidney disease (ADPKD) in Japan were estimated. Hospital-based nationwide surveys were conducted in 1995. The number of ADPKD patients who visited hospitals but were not on chronic dialysis was estimated to be 10,000 (95% confidence interval: 8,200–11,900) and that of ADPKD patients on dialysis was 4,590, yielding a prevalence of ADPKD of 117 per million population at the end of 1994 (95% confidence interval: 102–132). The prevalence increased with age and reached a peak value of 261 per million population at the age group of 55–59 years. The rate of end-stage renal disease among living patients was calculated based on the assumption that the prevalence of ADPKD in the population under the age of 55 years was 261 per million population. The rate of end-stage renal disease increased with the progression of the patients’ age, reaching 49% at the age of 65–69 years and declining thereafter. Conclusion: The hospital-based prevalence of ADPKD is lower than the autopsy-based prevalence, suggesting that a fairly large number of these patients do not receive medical care in their lifetime. The probability of end-stage renal disease is at most 50% among ADPKD patients who visit a hospital.

Newly developed ST-T abnormalities on the electrocardiogram and chronologic changes in cardiovascular risk factors

An ST-T abnormality on an electrocardiogram (ECG) is known to independently predict subsequent morbidity and mortality from cardiovascular diseases. But how ST-T abnormality develops in relation to chronologic changes in cardiovascular risk factors has not been fully discussed. Sixty-eight men whose ECG had been initially normal but who exhibited ST-T abnormality later (ST-T subjects) were identified among 21,579 apparently healthy adults who had undergone comprehensive health examinations for > 10 years. Echocardiography proved that 26 of 29 examinees among ST-T subjects had left ventricular hypertrophy. Antihypertensive drugs were given to 26 of the ST-T subjects. Their cardiovascular risk factors were chronologically reviewed from 10 years before the onset of definite ST-T abnormality, and were compared with those of 68 men whose ECG had remained consistently normal for 10 years (controls). Mean values of systolic and diastolic blood pressure gradually increased over 10 years (from 127/78 to 144/84 mm Hg) among ST-T subjects, but showed little change (from 122/76 to 124/77 mm Hg) during the same period in controls. The time course of blood pressure over 10 years was similar in ST-T subjects, irrespective of final blood pressure level. Mean serum cholesterol and glucose increased over 10 years in both ST-T and control subjects. Uric acid decreased over 10 years (from 6.1 to 5.6 mg/dl) only in ST-T subjects. Multivariate analysis revealed that blood pressure and uric acid before onset of ST-T abnormality were chronologically changed independent of other risk factors. The time course of risk factors may be of great importance in the development of cardiovascular disorders.