Legal psychoactive substances as risk factors for sleep-related bruxism: a nationwide Finnish Twin Cohort study.

AIMS: Different psychoactive factors including alcohol, coffee and tobacco, are considered as risk factors for bruxism. Often, heavy drinking and generous intake of coffee are correlated with smoking. Interactions between these agents may confound studies. The aim was to investigate the possible independent effects of drinking alcohol and coffee consumption on the occurrence of bruxism. METHODS: Data derived from the Finnish Twin Cohort study consisting of 12,502 twin individuals (45.6% men, 54.4% women, mean age 44 years) born during the 1930-1957. The twins responded to a questionnaire sent in 1990 (response rate of 77%) consisting of 103 multiple-choice questions, seven dealing with tobacco use, four on alcohol use, one about coffee consumption and two with bruxism. RESULTS: Increasing alcohol intake raised the risk for weekly bruxism even when adjusted for smoking status [heavy drinking odds ratio (OR) 1.9; 95% CI 1.23-2.84, binge drinking OR 1.6; 95% CI 1.28-2.12, and passing-out due to excessive alcohol intoxication at least twice within the previous year OR 1.5; 95% CI 1.09-2.18]. The situation was similar to that for coffee consumption of more than eight cups per day (OR 1.4; 95% CI 1.01-1.98). Interaction analyses for 'smoking with risk factors' revealed no statistically significant interactions. Current smoking was an independent risk factor for bruxism in all models (OR 2.3-2.7). CONCLUSION: Given the observed associations between alcohol drinking, binge drinking, passing-out due to excessive alcohol intake and coffee consumption, the results support our hypothesis of an independent association of both alcohol use, and coffee consumption with bruxism.

Coffee consumption, serum gamma-glutamyltransferase and risk of type II diabetes.

OBJECTIVES: To study the joint association of coffee consumption and serum gamma-glutamyltransferase (GGT) levels on the risk of developing type II diabetes. DESIGN, SETTING AND SUBJECTS: A total of 21,826 Finnish men and women who were 35-74 years of age and without any history of diabetes at baseline (years 1982, 1987, 1992 and 1997) were included in the present analyses. They were prospectively followed up for onset of type II diabetes (n=862 cases), death or until the end of the year 2002. Coffee consumption, serum GGT and other study parameters were determined at baseline using standardized measurements. Analyses were stratified by the serum GGT level classified into two classes using the 75th sex-specific percentiles as the cut point. RESULTS: Coffee consumption was significantly and inversely associated with incident diabetes among both men and women. Serum GGT modified the association between coffee consumption and incident diabetes. Subjects in the high category of coffee consumption with the GGT level > or = 75th percentile showed a significant inverse association for women, and for both sexes combined. The association was not significant in subjects with the GGT level < or = 75th percentile. There was a significant interaction effect of GGT and coffee consumption on risk of type II diabetes in data of women (P=0.05) and in both sexes combined (P=0.02). CONCLUSIONS: Habitual coffee consumption is associated with lower incidence of type II diabetes particularly in those with higher baseline serum GGT levels.

Role of genetic and environmental influences on heart rate variability in middle-aged men.

Our aim was to estimate causal relationships of genetic factors and different specific environmental factors in determination of the level of cardiac autonomic modulation, i.e., heart rate variability (HRV), in healthy male twins and male twins with chronic diseases. The subjects were 208 monozygotic (MZ, 104 healthy) and 296 dizygotic (DZ, 173 healthy) male twins. A structured interview was used to obtain data on lifetime exposures of occupational loading, regularly performed leisure-time sport activities, coffee consumption, smoking history, and chronic diseases from 12 yr of age through the present. A 5-min ECG at supine rest was recorded for the HRV analyses. In univariate statistical analyses based on genetic models with additive genetic, dominance genetic, and unique environmental effects, genetic effects accounted for 31-57% of HRV variance. In multivariate statistical analysis, body mass index, percent body fat, coffee consumption, smoking, medication, and chronic diseases were associated with different HRV variables, accounting for 1-11% of their variance. Occupational physical loading and leisure-time sport activities did not account for variation in any HRV variable. However, in the subgroup analysis of healthy and diseased twins, occupational loading explained 4% of the variability in heart periods. Otherwise, the interaction between health status and genetic effects was significant for only two HRV variables. In conclusion, genetic factors accounted for a major portion of the interindividual differences in HRV, with no remarkable effect of health status. No single behavioral determinant appeared to have a major influence on HRV. The effects of medication and diseases may mask the minimal effect of occupational loading on HRV.

Physical activity and the risk of pneumonia in male smokers administered vitamin E and beta-carotene.

It has been proposed that moderate exercise may enhance the immune system. We evaluated whether physical activity at work or at leisure is associated with the risk of pneumonia, and whether the antioxidants vitamin E and beta-carotene affect pneumonia risk in physically active people. A cohort of 16 804 male smokers aged 50-69 years and working at study entry was drawn from the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study, which examined the effect of vitamin E, 50 mg/day, and beta-carotene, 20 mg/day, on lung and other cancers. Physical activity at work, and the type of leisure-time exercise, were recorded at study entry. We retrieved the first occurrence of hospital-treated pneumonia during a 3-year follow-up from the National Hospital Discharge Register (133 cases). Physical activity at work and at leisure had no association with the risk of pneumonia. In participants with physically loading jobs, neither vitamin E nor beta-carotene affected the risk of pneumonia. In participants carrying out moderate or heavy exercise at leisure, beta-carotene had no effect, but vitamin E reduced the risk of pneumonia by 50% (95% CI: 16-70%). Previously, exercise has been shown to affect diverse laboratory measures of the immune system which are, however, only surrogate markers for the resistance to infections. The lack of association between physical activity and the risk of pneumonia observed in our study emphasizes the problem of drawing conclusions from surrogate end points. The finding that vitamin E reduced the risk of pneumonia in persons carrying out leisure-time exercise warrants further study.

Effects of coffee consumption on glucose tolerance, serum glucose and insulin levels--a cross-sectional analysis.

OBJECTIVE: Coffee has several metabolic effects that could reduce the risk of type 2 diabetes. Our objective was to examine the effects of coffee consumption on glucose tolerance, glucose and insulin levels. RESEARCH DESIGN AND METHODS: A subsample of subjects aged 45 to 64 years in 1987 and in 1992 from the population-based FINRISK study (12,287 individuals) was invited to receive the standard oral glucose tolerance test at baseline. Plasma samples were taken after an overnight fast, and a two-hour oral glucose tolerance test was administered. Fasting and two-hour plasma glucose and insulin were measured in 2434 subjects with data on coffee use and potential confounders. RESULTS: After adjustment for potential confounding factors (age, body mass index, systolic blood pressure, occupational, commuting and leisure time physical activity, alcohol and tea drinking, smoking), coffee consumption was significantly and inversely associated with fasting glucose, two-hour plasma glucose, and fasting insulin in both men and women. Coffee consumption was significantly and inversely associated with impaired fasting glucose, impaired glucose regulation, and hyperinsulinemia among both men and women and with isolated impaired glucose tolerance among women. CONCLUSIONS: In this cross-sectional analysis, coffee showed positive effects on several glycemia markers.

Healthy lifestyles of former Finnish world class athletes.

Recently, Sarna et al. (Med. Sci. Sports Exerc. 25:237-244, 1993) reported increased mean life expectancy in former world class athletes. Because lifestyle is associated with longevity, we have examined whether health habits of former Finnish male athletes (N = 1274; present mean age: 57.5, range: 36-94 yr) differed from those of noncompetitive referents (N = 788; mean age: 55.7, range: 39-87 yr). The athletes had represented Finland in international competitions in endurance (N = 177), power (N = 454), or other ("mixed") events (N = 643) from 1920-1965. Data on physical characteristics, sociodemographic factors, and health habits were obtained from questionnaires. All dependent variables in an analysis of covariance and in a logistic regression analysis were adjusted for age and occupation. Both leisure aerobic and work activity of all athlete groups was higher (P < 0.01) than that of referents. Compared with the referents, both power and "mixed" athletes were more prone to eat fruits and vegetables and to avoid vitamin supplements, but less prone to use butter and high-fat milk, and to smoke (odds ratios different from 1.0, P < 0.05). Also endurance athletes smoked less and drank less alcohol than the referents (P < 0.05). Higher leisure aerobic activity and less frequent smoking after athletic years might explain higher life expectancy of Finnish athletes.