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Simo Näyhä

Publications and source records attributed to Simo Näyhä.

12 recordsLinked to original sources

Factors affecting outdoor exposure in winter: population-based study.

The extent of outdoor exposure during winter and factors affecting it were examined in a cross-sectional population study in Finland. Men and women aged 25-74 years from the National FINRISK 2002 sub-study (n=6,591) were queried about their average weekly occupational, leisure-time and total cold exposure during the past winter. The effects of gender, age, area of residence, occupation, ambient temperature, self-rated health, physical activity and education on cold exposure were analysed. The self-reported median total cold exposure time was 7 h/week (8 h men, 6 h women),<1 h/week (2 h men, 0 h women) at work, 4 h/week (5 h men, 4 h women) during leisure time and 1 h/week (1 h men, 1.5 h women) while commuting to work. Factors associated with increased occupational cold exposure among men were: being employed in agriculture, forestry and industry/mining/construction or related occupations, being less educated and being aged 55-64 years. Factors associated with increased leisure-time cold exposure among men were: employment in industry/mining/construction or related occupations, being a pensioner or unemployed, reporting at least average health, being physically active and having college or vocational education. Among women, being a housewife, pensioner or unemployed and engaged in physical activity increased leisure-time cold exposure, and young women were more exposed than older ones. Self-rated health was positively associated with leisure time cold exposure in men and only to a minor extent in women. In conclusion, the subjects reported spending 4% of their total time under cold exposure, most of it (71%) during leisure time. Both occupational and leisure-time cold exposure is greater among men than women.

Adult↗

Cause-specific mortality of grand multiparous women in Finland.

Knowledge is limited on mortality of grand multiparous women (> or =5 deliveries), whose hormonal, metabolic, and social conditions differ from the average. The authors studied overall and cause-specific mortality in 1974-2001 among 87,922 grand multiparous women including 3,678 grand grand multiparous women (> or =10 deliveries) in Finland. Standardized mortality ratios were defined as ratios of observed to expected numbers of deaths, both derived from national cause-of-death files. During follow-up, 18,870 grand multiparous women and 625 grand grand multiparous women died (standardized mortality ratios (SMRs) = 0.95 and 1.01, respectively). Decreased mortality among grand multiparous women was found for cancers of the breast (SMR = 0.64, 95% confidence interval (CI): 0.59, 0.69), corpus uteri (SMR = 0.68, 95% CI: 0.56, 0.80), ovary (SMR = 0.68, 95% CI: 0.60, 0.75), bladder (SMR = 0.59, 95% CI: 0.41, 0.82), and respiratory tract (SMR = 0.80, 95% CI: 0.72, 0.88). The only malignant tumor associated with elevated mortality was kidney cancer (SMR = 1.38, 95% CI: 1.21, 1.56). The standardized mortality ratio was also low for dementia (SMR = 0.78, 95% CI: 0.72, 0.84), respiratory diseases (SMR = 0.80, 95% CI: 0.75, 0.85), and accidents and violent causes (SMR = 0.79, 95% CI: 0.73, 0.84). Mortality from diabetes mellitus (SMR = 1.42, 95% CI: 1.29, 1.55) and ischemic heart disease (SMR = 1.10, 95% CI: 1.08, 1.13) was increased. According to this study, overall mortality among grand multiparous women is not elevated. Low mortality from cancers is offset by higher mortality from cardiovascular conditions and diabetes mellitus.

Adult↗

Environmental temperature and mortality.

In Finland, mortality increases steeply in autumn, reaches a peak during the Christhmas holidays and declines slowly towards a trough in August. The relative excess in daily mortality (peak vs. trough) is 30% for coronary heart disease, 40% for cerebral vascular accidents and 90% for diseases of the respiratory organs. There is a secondary peak in Midsummer, especially in coronary deaths of working aged men. Mortality is lowest at mean daily temperature of +14 degrees C, and it increases slowly with falling temperature and steeply with increasing temperature. An estimated 2000-3000 extra deaths occur in Finland during the cold season, most of which are people aged 65 years and over but 20% at working age. The number of people dying from high temperatures (over +14 degrees C) in this country in a normal year is 100-200. Heat deaths are mostly certified as being due to cardiovascular or respiratory conditions. Exposure to cold air causes a rise in blood pressure and haemoconcentration which lead to increased tendency to vascular thromboses. In hot weather, haemoconcentration due to sweating and perspiration increases blood viscosity and the risk of thrombosis. Both cold and heat are significant public health hazards which should be taken into account in health care and education of health professionals.

Acclimatization↗

Fluoride in the drinking water and the geographical variation of coronary heart disease in Finland.

BACKGROUND: Fluoride in drinking water prevents dental disease, which in turn has been reported to increase the risk of coronary heart disease (CHD). Since mortality from CHD in Finland is high in the north-east where the fluoride content of drinking water is low, the association was examined here in more detail. DESIGN: Mortality from CHD during the period 1961-1995 in 365 rural areas of Finland (188 888 deaths) was linked with 2131 drinking water fluoride determinations performed in 1958 using negative binomial regression, adjustments being made for sex, age, mean income of the resident commune and drinking water magnesium and calcium. RESULTS: An inverse J-shaped relationship was found between drinking water fluoride and CHD, the association being most pronounced in the 1960s and levelling off consistently as a function of time. In 1961-1970, the adjusted mortality from CHD was 22% (95% confidence interval 18-27%) lower in the fourth quintile of fluoride (0.15-0.30 mg/l) than in the first quintile (0.00-0.06 mg/l) but this deficit reduced to 13% (7-18%) in 1991-1995. CONCLUSIONS: Although causality cannot be asserted, the geographical pattern of CHD in Finland is consistent with the concentration of fluoride in drinking water. One mechanism could be that fluoride prevents dental infections, which in turn reduces mortality from CHD. The more widespread use of fluoridated toothpastes, soft drinks and certain food items since the 1960s may have reduced the significance of drinking water as a source of fluoride.

Adult↗

Physical activity and social status in adolescence as predictors of physical inactivity in adulthood.

BACKGROUND: Physical inactivity is related to an increased risk of certain chronic diseases. The aim here was to evaluate how physical activity and social status in adolescence are associated with physical inactivity in adulthood. METHODS: The sample comprised 3664 males and 4130 females who answered questions on physical activity and social status at 14 and 31 years of age in follow-up surveys of the Northern Finland birth cohort of 1966. Associations between explanatory factors and physical inactivity in adulthood were analyzed using multivariable logistic regression. RESULTS: Infrequent participation in sports after school hours at 14 years of age and, in males, additionally a low grade in school sports, was associated with physical inactivity at the age of 31 years, independent of social circumstances in adulthood. Low social class of the childhood family was associated with physical inactivity in adolescence but not with inactivity at 31 years of age. Poor school achievement in adolescence was associated with adult inactivity independent of adolescent physical activity. CONCLUSION: Infrequent participation in sports, a low grade in school sports, and poor school achievements in adolescence were associated with physical inactivity in adulthood. Participation in sports is to be strongly supported among all adolescents because of its long-term beneficial effects on adult health through its tendency to reduce the probability of adult inactivity.

Adolescent↗

Adolescent participation in sports and adult physical activity.

BACKGROUND: Physical activity in adolescence has been reported to enhance physical activity in adulthood, but detailed information on the enhancing effect of different types of adolescent sports is lacking. We evaluated the association between participation in different types of adolescent sports and physical activity in adulthood. METHODS: The sample comprised 7794 males and females who responded to the mailed questions on physical activity status at age 14 years and at age 31 years in follow-up surveys of the Northern Finland 1966 birth cohort. The associations between adolescent participation in different sports and adult physical activity was examined by multinomial logistic regression. RESULTS: Frequent participation in sports after school hours in adolescence was associated with a high level of physical activity in adulthood. In males, adolescent participation in ball games, intensive endurance sports, track and field, and combat sports was associated with a high or very high level of adult activity. In females, the same applied to adolescent participation in running, orienteering, track and field, cycling, gymnastics, and riding. Adolescent participation in ball games increased participation in ball games in adulthood, especially in males, while participation in cross-country skiing, running, and orienteering provided the greatest stimulation to carry over of some endurance sport to adulthood. CONCLUSIONS: Participation in sports at least once a week among females and twice a week among males was associated with high level of physical activity in later life. Adolescent participation in the intensive endurance sports, and some sports that require and encourage diversified sports skills, appeared to be most beneficial with respect to the enhancement of adult physical activity.

Adolescent↗

Occupational physical activity is related to physical fitness in young workers.

PURPOSE: We evaluated the association between occupational physical activity and fitness in young workers, taking into account leisure-time physical activity, body size, and smoking. METHODS: The study population comprised 2188 men and 1987 women, members of the Northern Finland birth cohort 1966, who participated in the 1997-1998 follow-up survey and were employed at the time of the survey. Cardiorespiratory fitness was measured by a 4-min step test and muscular fitness by tests of maximal isometric handgrip and isometric trunk extension. Information on occupational and leisure-time physical activity and smoking was obtained by questionnaire, and body height and weight were measured during medical examination. The data were analyzed by analysis of variance and Cox regression. RESULTS: Men doing heavy physical work scored better in cardiorespiratory fitness, handgrip strength, and trunk muscle endurance than men doing lighter work; the finding for cardiorespiratory fitness was similar in women. The associations were independent of leisure-time physical activity, body weight and height, and smoking. CONCLUSION: A positive association was found between heavy physical work and a high level of fitness in young workers. Due to limitations of the study setting, causality cannot be asserted, but a training effect of heavy work would not seem unreasonable. Previous studies have suggested a reversal of the positive effect of heavy work on fitness with advancing age. Therefore, regular monitoring of workers' fitness at an early phase is justified to enable assessment of workers' capacity for heavy jobs and any possible need for fitness-improving activities.

Adult↗

Traffic deaths and superstition on Friday the 13th.

OBJECTIVE: This study compared deaths from traffic accidents on Friday the 13th with those on other Fridays in a national population. METHOD: The author examined the daily deaths from traffic accidents by sex and age and the mean daily temperature in Finland, 1971-1997. Adjusted risk ratios for death on Friday the 13th versus other Fridays were obtained by negative binomial regression. RESULTS: In men, the adjusted risk ratio for dying on Friday the 13th, compared with other Fridays, was 1.02, but for women, it was 1.63. An estimated 38% of traffic deaths involving women on this day were attributable to Friday the 13th itself. CONCLUSIONS: Friday the 13th may be a dangerous day for women, largely because of anxiety from superstition. The risk of traffic deaths on this date could be reduced by one-third, although the absolute gain would remain very small: only one death per 5 million person-days.

Accidents, Traffic↗

Incidence of frostbite and ambient temperature in Finland, 1986-1995. A national study based on hospital admissions.

OBJECTIVES: The association of frostbite with ambient temperature in Finland is not known. The present study determined the incidence of frostbite and its association with sex, age and ambient temperature in a nationwide sample. STUDY DESIGN: The first admissions of all patients (n=1,275) admitted to hospital in Finland during the period 1986-1995 with frostbite as a principal or secondary diagnosis were associated with ambient temperature on the day of admission. RESULTS: The incidence of frostbite was 2.5 per 100,000 inhabitants, it was higher in males than females and increased linearly with age. The annual incidence of frostbite started to rise at below -15 degrees C and was considerable at under -20 degrees C, particularly in northern Finland. However, the daily incidence increased most in the urban area of Helsinki. CONCLUSION: In the north, the main factor is the large number of cold days in the year. The daily incidence may be affected by urban lifestyle, possibly fashion, and inability to protect oneself against the cold.

Adolescent↗

Cold and the risk of cardiovascular diseases. A review.

The higher occurrence of cardiovascular diseases in winter is well known, and several explanatory mechanisms have been suggested based on increased blood pressure, haematological changes and respiratory infections. Most investigations have used ecological data such as daily temperatures recorded at weather stations and mortality in the general population. Cause-specific mortality is the outcome measure most commonly used. Local myocardial infarction community registers would offer an ideal database, but may suffer from inadequate statistical power. Hospital discharge records, linked with out-of-hospital deaths, provide a powerful tool for detecting even weak effects of temperature. The association of coronary heart disease and temperature is usually U-shaped, mortality being lowest within the range 15-20 degrees C and higher on both sides of this. The increase in mortality on the colder side is in the region of 1% per 1 degree C fall in temperature, but the increase on the warmer side may be very steep. The exact location of the minimum temperature and the magnitude of the effect can vary between countries. In Finland the winter excess mortality from coronary heart disease has been levelling off during recent decades, but it still represents approximately 6% of annual deaths due to this condition.

Cardiovascular Diseases↗