To study whether persistent leisure-time physical activity (PA) during adulthood predicts use of antidepressants later in life.
The Finnish Twin Cohort comprises same-sex twin pairs born before 1958, of whom 11 325 individuals answered PA questions in 1975, 1981 and 1990 at a mean age of 44 years (range 33-60). PA volume over 15-years was used as the predictor of subsequent use of antidepressants. Antidepressant use (measured as number of purchases) for 1995-2004 were collected from the Finnish Social Insurance Institution (KELA) prescription register. Conditional logistic regression was conducted to calculate odds ratios (OR) with 95% confidence intervals (CI) for the use of antidepressants in pairs discordant for PA (642, including 164 monozygotic (MZ) pairs).
Altogether 229 persons had used at least one prescribed antidepressant during the study period. Active co-twins had a lower risk (unadjusted OR 0.80, 95%CI 0.67-0.95) for using any amount of antidepressants than their inactive co-twins; trends being similar for DZ (0.80, 0.67-0.97) and MZ pairs (0.78, 0.51-1.17). The lowest odds ratio (0.51, 0.26-0.98) was seen among MZ pairs after adjusting for BMI, smoking and binge drinking. The point estimates were similar but non-significant for long-term antidepressant use (4+purchases equivalent to 12 months use).
Self-reported physical activity and low number of discordant MZ pairs.
Use of antidepressants was less common among physically active co-twins even when shared childhood experiences and genetic background were controlled for. Physical activity in midlife may therefore be important in preventing mild depression later in life.
To examine whether adolescent flexibility, endurance strength, and physical activity can predict the later occurrence of recurrent low back pain, tension neck, or knee injury.
In 1976, 520 men and 605 women participated in a sit and reach test (flexibility) and a 30 second sit up test (endurance strength). In 1976 and 2001 (aged 37 and 42 years) they completed a questionnaire. Lifetime occurrence and risk of self reported low back pain and self reported, physician diagnosed tension neck and knee injury were calculated for subjects divided into tertiles by baseline results of strength and flexibility tests.
Men from the highest baseline flexibility tertile were at lower risk of tension neck than those from the lowest tertile (odds ratio (OR) 0.51, 95% confidence interval (CI) 0.28 to 0.93). Women from the highest baseline endurance strength tertile were at lower risk of tension neck than those from the lowest tertile (OR 0.60, 95% CI 0.40 to 0.91). Men from the highest baseline endurance strength tertile were at higher risk of knee injury than those from the lowest tertile (OR 1.96, 95% CI 1.05 to 3.64). Men who at school age participated in physical activity were at lower risk of recurrent low back pain (OR 0.61; 95% CI 0.42 to 0.88) than those who did not.
Overall good flexibility in boys and good endurance strength in girls may contribute to a decreased risk of tension neck. High endurance strength in boys may indicate an increased risk of knee injury.
Cites: Spine (Phila Pa 1976). 1998 Jan 15;23(2):235-439474732
Cites: Med Sci Sports Exerc. 1997 Aug;29(8):1062-89268964
In order to study the role of occupational exposure in the etiology of asthma, 78 asthmatics and 56 nonasthmatics from the Finnish twin cohort were investigated by means of a postal questionnaire. Among those studied were 31 identical twin pairs discordant with regard to asthma (i.e., only one member of the pair had asthma). The questionnaire inquired into the diagnosis and status of the asthma, smoking habits, atopic background, smoking history of the parents, and history as regards pets, and requested a detailed description of occupational exposure to airway allergens and irritants. Classification into asthmatics and nonasthmatics was based on the information gathered with the questionnaire, supplemented by other information whenever possible. Estimation of exposure was based on the subject's own report, on the work descriptions, and on the general knowledge about the exposure levels associated with work tasks in question. Exposure to organic solvents was found only in the asthmatic members of the discordant pairs, and none of the nonasthmatic persons had been exposed to solvents. There were no statistically significant differences as regards exposure to other unspecific irritants. Combined exposure to organic allergens and airway irritants was more common in the asthmatics than in the nonasthmatics (P = 0.009). Exposure to irritants was also more common among the asthmatics than the nonasthmatics with similar exposure to organic allergens (P = 0.004).
The Finnish Twin Cohort study (27,776 individuals; all twins of the same sex born before 1958 and alive in 1967) detected 316 cases of epileptic seizures occurring in 310 twin pairs: 89 monozygotic pairs and 221 dizygotic pairs, including three concordant monozygotic pairs and three concordant dizygotic pairs. The ratio of the observed to expected number of concordant pairs for epileptic seizures was 5.48 (90% CL 1.5-14.2) in monozygotic and 2.12 (90% CL 0.6-5.5) in dizygotic pairs. The results suggest that 8% to 27% of the incidence of epileptic seizures is related to genetic variability. The study of environmental differences in discordant monozygotic pairs should provide insights into the etiology of this group of disorders.
Physical activity is an important aspect of health behavior and life-style, when considering the possibilities to prevent premature deaths and sustain functional capacity. We studied former Finnish male athletes and controls to investigate the effects of long-lasting participation in vigorous sports on health, and the main findings are reviewed here. The athletes represented Finland between the years 1920-1965 at least once in international competitions. The following sports were selected: track and field athletics, cross-country skiing, soccer, ice hockey, basketball, boxing, wrestling, weight lifting, and shooting. The full name, place and date of birth were traced for 2613 (97.7%) men. The referent subjects (N = 1712) were selected among those Finnish men who, at the age of 20, were classified completely healthy at the medical examination for induction into military service. In most analyses we grouped the sports according to the type of training needed to achieve maximal results, i.e., principally aerobic training, principally anaerobic training or mixed. In 1985, a questionnaire on physical activity, health and health habits was mailed to surviving former athletes and referents (N = 2851, 65.9% of the original cohort). Follow-up for morbidity and mortality was based on national medical registries. We found that former aerobic sports athletes (endurance and mixed sports) in particular have high total and active life expectancy and low risk for ischemic heart disease and diabetes in later years. On the other hand, they have slightly higher risk for lower-limb osteoarthritis. Overall, the benefits of physically active life-style on health were clearly higher than the adverse effects.
Besides familial Alzheimer's disease (AD), the genetic susceptibility has also been found in sporadic cases of AD, mostly related to the apolipoprotein E polymorphism. The penetrance of AD is determined by age and probably by environmental exposure. Gene-environment interaction of a disease can be examined through studies of twins. The relative roles of genetic and environmental influences can be estimated by comparing the concordance rates between monozygotic (MZ) and dizygotic (DZ) twins. Genetic models can be used to specify contributions both from genetic as well as shared and unique environmental effects. The role of environmental factors can be investigated in the co-twin control study, either by comparing environmental exposure in MZ twins discordant for a disease or by comparing MZ twins discordant for an exposure suspected of causing a particular disease. The sampling of twin pairs AD can be carried out using voluntary recruitment, linkage of twin and hospital discharge registries or screening of twin registry population. Potential sources of biases in sampling are discussed. The majority of the published twin studies on AD are case reports or based on selected materials. In MZ pairs, the concordance rates for AD have varied between 31% and 83%. Only one co-twin control study in twins discordant for AD has been published. Published twin studies on AD are briefly reviewed.
Few studies have been published on the overall survival of adult patients with asthma. A cohort study was performed to assess the mortality from all causes, from chronic obstructive pulmonary disease, and from lung cancer among adult asthmatic subjects.
A population of 31,110 Finnish adult women and men, mostly twins, was studied to compare the 16 year mortality rates among asthmatic (n = 471) and non-asthmatic persons. A further 293 twin pairs, discordant for asthma, were also studied to determine whether the mortality of patients with asthma differs from that of their age matched siblings.
Mortality from all causes was increased among asthmatic adults (age adjusted hazard ratios 1.49, 95% CI 1.09 to 2.05 for men and 1.53, 95% CI 1.10 to 2.13 for women), and mortality due to chronic obstructive pulmonary diseases was also significantly increased in asthmatic subjects. The risk of death due to lung cancer was increased in men with asthma (hazard ratio adjusted for smoking 3.19, 95% CI 1.39 to 7.31). The risk ratios found among twins discordant for asthma corresponded to those found in the whole cohort.
Survival in adults with asthma is worse than in those without asthma. The excess deaths due to chronic obstructive pulmonary disease may explain some part of the increased mortality rates, but not all of it.
Examples of gene-environment interaction in human behavioral data are relatively rare; those that exist have used simple, dichotomous measures of the environment. The authors describe a model that allows for the specification of more continuous, more realistic variations in environments as moderators of genetic and environmental influences on behavior. Using data from a population-based Finnish twin study, the authors document strong moderating effects of socioregional environments on genetic and environmental influences on adolescent alcohol use, with nearly a five-fold difference in the magnitude of genetic effects between environmental extremes. The incorporation of specific environmental measures into genetically informative designs should prove to be a powerful method for better understanding the nature of gene-environment interaction and its contribution to the etiology of behavioral variation.
Regular drinking by age 14 years is a significant risk factor for alcoholism, and genetically informative data suggest that whether a young adolescent abstains or drinks is largely attributable to familial (or other shared) environmental factors.
Three consecutive birth cohorts of Finnish twins, enrolled into a longitudinal study at age 11 to 12 years, completed a follow-up questionnaire within 3 months of their 14th birthdays. The sample included 1380 twin sisters and 1330 twin brothers at age 14, and at that age, 35.4% reported using alcohol. Genetic analyses (model-fitting of twin pair data) and epidemiological analyses (logistical regressions of data from individual twins) were conducted to examine predictive factors of drinking versus abstinence at age 14.
Polychoric correlations were substantial across all same-sex twin pairs but were lower for brother-sister twins, suggesting significant influences of common environments, with some sex-specific effects. Common environmental effects were equivalent in male and female adolescents and accounted for 76% of the total variation in abstinence/drinking. Logistical regression analyses among 2206 individual twins with complete data on risk-relevant measures at both baseline and follow-up identified significant predictors of drinking or abstaining at age 14, including female sex, twin sibling of the opposite sex, accelerated pubertal development, and the twins' assessments, made at age 12, of reduced parental monitoring and a less supportive home atmosphere; drinking at age 14 was also predicted by behaviors rated by the twins' classroom teachers 2 years earlier, increasing with rated behavioral problems but decreasing with rated emotional problems.
Our results show that environmental factors shared by twin siblings account for most of the variance in abstaining or drinking at age 14. We identify predictors of drinking in the adolescent twins' home environments and in their dispositional behaviors, sibling interactions, and pubertal timing.
This study set out to estimate the 12-month prevalence of DSM-III-R major depressive episode (MDE) and to analyse factors associating with psychosocial impairment, episode duration, phenomenology and symptom severity in a representative general population sample of adolescents (15-19-year-olds) and young adults (20-24-year-olds).
The Finnish Health Care Survey '96 (FINHCS '96) was a cross-sectional nationwide epidemiological study. A random sample of 509 adolescents and 433 young adults was interviewed in 1996. MDE was assessed by University of Michigan Composite Diagnostic Interview Short-Form.
The 12-month prevalence of MDE was 5.3 % for adolescents (females 6.0%, males 4.4%) and 9.4% for young adults (females 10.7%, males 8.1%). When moderate psychosocial impairment was included in case definition, the prevalences were lowered by 20-25%. Increased impairment was associated with drunkenness at least twice a month, a higher mean number of depressive symptoms and impaired concentration. The median episode duration was 1 month. No factors associating with duration were found. With the exception of symptoms related to appetite being more common among females than males, the phenomenology of MDE was mainly independent of age and gender.
Episodes of major depression among adolescents and young adults in the general population are short but often associated with psychosocial impairment, especially if frequent drunkenness coexists.