Biomedical subjects

Yoshio Komachi

Publications and source records attributed to Yoshio Komachi.

5 recordsLinked to original sources

PubMed2004

[Potential risk factors aggravating airway allergy--aspects of involvement of airtight housing and passive smoking].

OBJECTIVES: The involvement of tightly insulated housing conditions and passive smoking in atopic sensitization, a major risk factor for airway allergy, was examined with nonsmoking adult women and school-age children. SUBJECTS AND METHODS: The subjects were 382 nonsmoking healthy adult women (housewives) who underwent medical examinations for prevention of adult diseases conducted in a district of Osaka from 1995 to 1997, and 214 elementary school-children 9-12 years old living in an urban district of Osaka who underwent medical examinations at a health center in April, 2000 to prevent allergic diseases. We also examined the correlation between tightly insulated housing conditions and the amount of passive smoking based on family smoking habits with 170 children under 12 years old who had been under the care of a hospital pediatrics department between December, 1993 and May, 1994. A questionnaire was administered to all subjects to survey the housing structure (concrete/wooden housing), family smoking habits and visible mold proliferation in the kitchen in relation to airtight housing conditions, passive smoking and exposure to inhalant allergens. Atopic sensitization was assessed by positivity for serum house dust mite-specific IgE, and passive smoking was defined as a urinary cotinine level of more than 6 ng/mgCr. RESULTS: 1. Among the three factors, indoor mold proliferation and family smoking habits were positively and synergistically related with atopic sensitization to house dust mites. 2. Airtight conditions of concrete housing showed a promotional effect on passive smoking for housewives, but a suppressive effect for school-age children. 3. Taking into account the above results, the promotional effects of passive smoking on atopic sensitization appeared predominantly in the concrete housing-residence group of housewives and the wooden housing-residence group of school-age children. 4. Effects of visible mold proliferation in the kitchen on atopic sensitization appeared predominantly in wooden housing-residence group of housewives. CONCLUSIONS: The results suggest that involvement of the three factors in atopic sensitization is due to increased exposure to indoor inhalant allergens or enhanced IgE-antibody production (adjuvant effects of tobacco smoke) and the extent of their inpact varies depending on the individual life styles of the housewives and school-age children.

Adult↗

PubMed2004

[A strategy for assessing environmental influence on airway allergy using a regression binary tree-based method].

OBJECTIVE: To clarify the living environment factors that increase the risk of allergic sensitization to house dust mites, we applied a regression binary tree-based method (CART, Classification & Regression Trees) to an epidemiological study on airway allergy. The utility of the tree map in personal sanitary guidance for preventing allergic sensitization was examined with respect to feasibility and validity. SUBJECTS AND METHODS: A questionnaire was given to 386 healthy adult women, asking them about their individual living environments. Also, blood samples were collected to measure Dermatophagoides pteronyssinus (Dp)-specific IgE, the presence/absence of Dp-sensitization being expressed as positive/negative. The questionnaire consisted of nine items on (1) home ventilation by keeping windows open, (2) personal or family smoking habits, (3) use of air conditioners in hot weather, (4) type of flooring (tatami/wooden/carpet) in the living room, (5) visible mold proliferation in the kitchen, (6) type of housing (concrete/wooden), (7) residential area (heavy or light traffic area) (8) heating system (use of unventilated combustion appliances), and (9) frequency of cleaning (every day or less often). There also were queries on the past history of airway allergic diseases, such as bronchial asthma and allergic rhinitis. CART and a multivariate logistic regression analysis (MLRA) were performed. The subjects were first classified into two groups, with and without a history of airway allergic diseases (Groups WPH and WOPH). In each group, the involvement of living environment factors in Dp-sensitization was examined using CART and MLRA. RESULTS: In the MLRA study, individual living environment factors showed promotional or suppressive effects on Dp-sensitization with differences between the two groups. With respect to the CART results, the two groups were first split by the factor that had the most significant odds ratio for MLRA. In Group WPH, which had a Dp-sensitization risk of 19.5%, the first split was by the factor of visible mold proliferation in the kitchen into the factor-present group with a risk value of 45.5% and the factor-absent group with 13.5%. The mold proliferation group was split with reference to frequent cleaning, and the risk rose to 75% in the factor-absent group and to 100% when family smoking habits were reported. Group WOPH (the risk: 10.8%) was first split into two groups according to the use of air conditioners in hot weather for more than 6 hours a day or less, which showed risk values of 16.7% and 6.9%, respectively. The risk of the group that intensively used air conditioners fell to 8.3% with tatami as flooring in the living room, and, if others, rose to 20.8%. The risk of the factor-lacking group fell to 4.0% without wooden flooring. CONCLUSIONS: CART analysis enables us to express complex relationships between living environment factors and Dp-sensitization simply by a binary regression tree, pointing to preventive strategies that can be flexibly changed according to the individual living environments of the subjects.

Environment↗

PubMed2003

Fat and protein intakes and risk of intraparenchymal hemorrhage among middle-aged Japanese.

The authors examined the relation between low intakes of saturated fat and animal protein and risk of intraparenchymal hemorrhage in a 14-year prospective study (ending in 1997) of 4,775 Japanese aged 40-69 years who undertook a single 24-hour dietary recall. Compared with the highest quartile of energy-adjusted saturated fat intake (median, 17 g/day), multivariate relative risks, after adjustment for age, sex, community, total energy intake, and known cardiovascular risk factors, were 0.77 (95% confidence interval (CI): 0.42, 1.42) for the second quartile (12 g/day), 0.66 (95% CI: 0.34, 1.25) for the third quartile (8 g/day), and 0.30 (95% CI: 0.12, 0.71) for the lowest quartile (5 g/day); p for trend = 0.005. An inverse relation was observed among both hypertensives and nonhypertensives; the respective relative risks with a one standard deviation increase in saturated fat intake (15.4 g/day) were 0.72 (95% CI: 0.52, 1.00) and 0.36 (95% CI: 0.14, 0.95). Intake of animal protein tended to correlate inversely with risk; the relative risk with a one standard deviation increase in animal protein intake (17.6 g/day) was 0.79 (95% CI: 0.61, 1.02); p = 0.07. Results are similar to those recently reported for US women and together help to explain the high rate of this stroke subtype in Asian countries, where intakes of these nutrients are low.

Adult↗

PubMed2002

Trends in the incidence of coronary heart disease and stroke and the prevalence of cardiovascular risk factors among Japanese men from 1963 to 1994.

PURPOSE: To determine trends in the incidence of cardiovascular disease in Japan, we examined observational data on coronary heart disease, stroke, and cardiovascular risk factors among urban Japanese working men. SUBJECTS AND METHODS: The surveyed population included all male employees aged 40 to 59 years who worked for eight industrial companies in Osaka, the second largest metropolitan city in Japan. Surveillance for cardiovascular disease and risk factors was conducted from 1963 to 1994. RESULTS: The age-adjusted incidence of coronary heart disease increased from 0.4 per 1000 person-years during 1963 to 1970, to 1.5 per 1000 person-years during 1979 to 1986, and then plateaued until 1987 to 1994 (P for trend = 0.002), whereas the incidence of stroke declined from 1.2 per 1,000 person-years during 1971 to 1978, to 0.6 per 1,000 person-years in 1987 to 1994 (P for trend = 0.02). The age-adjusted mean (+/- SD) total cholesterol level, which was 4.87 +/- 2.88 mmol/L during 1963 to 1966, increased to 5.11 +/- 0.62 mmol/L during 1982 to 1983 (P <0.001), and 5.09 +/- 0.75 mmol/L during 1990 to 1991. Both mean systolic and diastolic blood pressures increased by 1 mm Hg between the periods of 1966 to 1967 and 1982 to 1983, and declined below the 1966 to 1967 levels during 1990 to 1991. The prevalence of smoking declined from 72% during 1975 to 1976, to 58% during 1990 to 1991 (P for trend <0.001). CONCLUSION: Although these findings were limited to urban middle-aged men, the increase in serum cholesterol is likely to attenuate the reduction in future rates of coronary heart disease in Japan that would have been expected to result from the declining prevalence of smoking.

Adult↗

PubMed1994

Can Blood Pressure in the Elderly be Reduced? Findings From a Long-term Population Survey in Japan.

To examine whether blood pressure (BP), a major risk factor of cardiovascular disease, can be controlled in the elderly as well as in middle-aged persons, we analyzed the data of observational studies on trends for BP and cardiovascular disease incidence in a northeast rural community of Japan. This community was the subject of an ongoing hypertension control program that was initiated in 1963. A significant decline in BP levels was noted in each sex-age group between 1963 and 1966 and 1987 and 1991. The decline was greater in older persons compared with younger individuals. The BP decline was attributable to an increase in antihypertensive medication use, beginning in the 1970s. We compared BP levels of untreated offspring and parents when both were 40 to 49 years old. Blood pressure levels were significantly lower in the offspring than in parents. This result and the large downward shift of BP distribution in the second decade of follow-up suggested that the improvements in diets and other environmental factors contributed to the BP decline. Between 1964 and 1968 and 1989 and 1992, stroke incidence declined 70% to 79% for all sex and age groups (40-69 and greater than 70 years). The number of totally dependent stroke patients decreased in both the middle-aged and the elderly between 1976 and 1991. The decline in stroke mortality tended to be larger in the surveyed community than in adjacent communities. These results indicated that hypertension control is effective in preventing stroke in the elderly as well as in the middle-aged.

Journal Article↗