Information on familial resemblance is important for the design of effective family-based interventions. We aimed to quantify familial correlations and estimate the proportion of variation ...attributable to genetic and shared environmental effects (i.e., familiality) for dietary intake variables and determine whether they vary by generation, sex, dietary quality, or by the age of the children. The study sample consisted of 1435 families (1007 mothers, 438 fathers, 1035 daughters, and 1080 sons) from the multi-center I.Family study. Dietary intake was assessed in parents and their 2-19 years old children using repeated 24-h dietary recalls, from which the usual energy and food intakes were estimated with the U.S. National Cancer Institute Method. Food items were categorized as healthy or unhealthy based on their sugar, fat, and fiber content. Interclass and intraclass correlations were calculated for relative pairs. Familiality was estimated using variance component methods. Parent-offspring (
= 0.11-0.33), sibling (
= 0.21-0.43), and spouse (
= 0.15-0.33) correlations were modest. Parent-offspring correlations were stronger for the intake of healthy (
= 0.33) than unhealthy (
= 0.10) foods. Familiality estimates were 61% (95% CI: 54-68%) for the intake of fruit and vegetables and the sum of healthy foods and only 30% (95% CI: 23-38%) for the sum of unhealthy foods. Familial factors explained a larger proportion of the variance in healthy food intake (71%; 95% CI: 62-81%) in younger children below the age of 11 than in older children equal or above the age of 11 (48%; 95% CI: 38-58%). Factors shared by family members such as genetics and/or the shared home environment play a stronger role in shaping children's intake of healthy foods than unhealthy foods. This suggests that family-based interventions are likely to have greater effects when targeting healthy food choices and families with younger children, and that other sorts of intervention are needed to address the intake of unhealthy foods by children.
Numerous factors influence late-life depressive symptoms in adults, many not thoroughly characterized. We addressed whether genetic and environmental influences on depressive symptoms differed by ...age, sex, and physical illness.
The analysis sample included 24 436 twins aged 40-90 years drawn from the Interplay of Genes and Environment across Multiple Studies (IGEMS) Consortium. Biometric analyses tested age, sex, and physical illness moderation of genetic and environmental variance in depressive symptoms.
Women reported greater depressive symptoms than men. After age 60, there was an accelerating increase in depressive symptom scores with age, but this did not appreciably affect genetic and environmental variances. Overlap in genetic influences between physical illness and depressive symptoms was greater in men than in women. Additionally, in men extent of overlap was greater with worse physical illness (the genetic correlation ranged from near 0.00 for the least physical illness to nearly 0.60 with physical illness 2 s.d. above the mean). For men and women, the same environmental factors that influenced depressive symptoms also influenced physical illness.
Findings suggested that genetic factors play a larger part in the association between depressive symptoms and physical illness for men than for women. For both sexes, across all ages, physical illness may similarly trigger social and health limitations that contribute to depressive symptoms.
Background: Asthma prevalence has been increasing especially in developed countries. The change seems to be associated with changes in lifestyle. We have made a prospective study to assess the effect ...of lifestyle factors, including smoking, educational level, physical activity and obesity, on adult onset asthma.
Methods: A population of 10 597 adult twins, initially free of asthma was followed for 9 years. The main outcome measure was questionnaire-based report of physician diagnosed asthma. Logistic regression was used to estimate the risk of asthma predicted by lifestyle factors, with adjustment for atopy and respiratory symptoms.
Results: Obesity at baseline increased asthma risk (multivariable adjusted OR=3.00, 95% CI: 1.64–5.50 for those with BMI≥30 compared to those with normal weight BMI: 20–24.99). Taller height was associated to lower asthma incidence. Leisure time physical activity had a slightly protective effect on asthma risk among men (
P for trend=0.037), while smoking and education did not have significant effects on the risk of adult onset asthma.
Conclusions: Obesity was associated to the risk of adult onset asthma, while short height and low leisure time physical activity can be considered as other potential risk factors.
The aim of this study was to estimate the contribution of genetic and environmental influences on motives for engaging in leisure‐time physical activity. The participants were obtained from the ...FinnTwin16 study. A modified version of the Recreational Exercise Motivation Measure was used to assess the motives for leisure‐time physical activity in 2542 twin individuals (mean age of 34.1 years). Linear structural equation modeling was used to investigate the genetic and environmental influences on motive dimensions. The highest heritability estimates were found for the motive dimensions of “enjoyment” men 33% (95% CI 23–43%), women 53% (95% CI 45–60%) and “affiliation” men 39% (95% CI 0.28–0.49%), women 35% (95% CI 0.25–0.43%). The lowest heritability estimates were found for others’ expectations men 13% (95% CI 0.04–0.25%), women 15% (95% CI 0.07–0.24%). Unique environmental influences explained the remaining variances, which ranged from 47% to 87%. The heritability estimates for summary variables of intrinsic and extrinsic motives were 36% and 32% for men and 40% and 24% for women, respectively. In conclusion, genetic factors contribute to motives for leisure‐time physical activity. However, the genetic effects are, at most, moderate, implying the greater relative role of environmental factors.
•The correlations between self-reported and measured values were high.•Self-reported measures are reasonably accurate for obesity in large cohort studies.•Women tended to underestimate and men ...overestimate their weight.•Older age increases height overestimation.•Monozygotic twins report measures more similarly than dizygotic twins.
To determine the accuracy of self-reported height, weight, body mass index (BMI) and waist circumference (WC) compared to the measured values, and to assess the similarity between self-reported and measured values within dizygotic (DZ) and monozygotic (MZ) twin pairs.
The data on self-reported and measured height, weight and WC values as well as measured hip circumference (HC) were collected from 444 twin individuals (53–67 years old, 60% women). Accuracies between self-reported and measured values were assessed by Pearson’s correlation coefficients, Cohen’s kappa coefficients and Bland-Altman 95% limits of agreement. Intra-class correlation was used in within-pair analyses.
The correlations between self-reported and measured values were high for all variables (r=0.86–0.98), although the agreement assessed by Bland-Altman 95% limits had relatively wide variation. The degree of overestimating height was similar in both sexes, whereas women tended to underestimate and men overestimate their weight. Cohen’s kappa coefficients between self-reported and measured BMI categories were high: 0.71 in men and 0.70 in women. Further, the mean self-reported WC was less than the mean measured WC (difference in men 2.5cm and women 2.6cm). The within-pair correlations indicated a tendency of MZ co-twins to report anthropometric measures more similarly than DZ co-twins.
Self-reported anthropometric measures are reasonably accurate indicators for obesity in large cohort studies. However, the possibility of more similar reporting among MZ pairs should be taken into account in twin studies exploring the heritability of different phenotypes.
Abstract Background and aims Nutritional epidemiology is increasingly shifting its focus from studying single nutrients to the exploration of the whole diet utilizing dietary pattern analysis. We ...analyzed associations between habitual diet (including macronutrients, dietary patterns, biomarker of fish intake) and lipoprotein particle subclass profile in young adults. Methods and results Complete dietary data (food-frequency questionnaire) and lipoprotein subclass profile (via nuclear magnetic resonance spectroscopy) were available for 663 subjects from the population-based FinnTwin12 study (57% women, age: 21–25 y). The serum docosahexaenoic to total fatty acid ratio was used as a biomarker of habitual fish consumption. Factor analysis identified 5 dietary patterns: “Fruit and vegetables”, “Meat”, “Sweets and desserts”, “Junk food” and “Fish”. After adjustment for sex, age, body mass index, waist circumference, physical activity, smoking status and alcohol intake, the “Junk food” pattern was positively related to serum triglycerides ( r = 0.12, P = 0.002), a shift in the subclass distribution of VLDL toward larger particles ( r = 0.12 for VLDL size, P < 0.001) and LDL toward smaller particles ( r = −0.15 for LDL size, P < 0.001). In addition, higher scores on this pattern were positively correlated with concentrations of small, dense HDL ( r = 0.16, P < 0.001). Habitual fish intake associated negatively with VLDL particle diameter (“Fish” pattern and biomarker) and positively with HDL particle diameter (biomarker). Conclusions Our results suggest that in young adults, higher habitual fish consumption is related to favorable subclass distributions of VLDL and HDL, while junk food intake is associated with unfavorable alterations in the distribution of all lipoprotein subclasses independent of adiposity and other lifestyle factors.
BackgroundAlthough recent genome-wide association studies have identified several genetic variants contributing to the complex aetiology of multiple sclerosis (MS), expression and functional studies ...are required to further understand its molecular basis.ObjectivesTo identify genes and pathways with differential expression in MS.DesignThe authors conducted a systematic review of seven microarray studies, in which expression in immune cells was compared between MS patients and controls. These studies include a previously unpublished study, which is described here in detail.Results and conclusionAlthough in general the overlap between studies was poor, 229 genes were found to be differentially expressed in MS in at least two studies, of which 11 were in three studies and HSPA1A in four studies. After excluding the authors' unpublished experiment which may have been affected by certain confounding factors and inclusion of treated subjects, 135 genes were identified in at least two studies. The differentially expressed genes were significantly associated with several immunological pathways, including interleukin (IL)-4, IL-6, IL-17 and glucocorticoid receptor signalling pathways. 15 of the 229 loci have shown some association with MS in published genome-wide association studies (p<0.0001), including three loci with confirmed MS risk variants.
OBJECTIVE: The authors investigated whether self-reported life satisfaction predicted suicide over a period of 20 years (1976-1995) in adults unselected for mental health status. METHOD: A nationwide ...sample of adults aged 18-64 years (N=29,173) from the Finnish Twin Cohort responded to a health questionnaire that included a life satisfaction scale (score range=4-20, with higher scores indicating greater dissatisfaction) that covered four items: interest in life, happiness, general ease of living, and feeling of loneliness. "Dissatisfied" subjects (life satisfaction score=12-20) were compared to "satisfied" subjects (score=4-6). Mortality data were derived from the national registry and analyzed with Cox regression. RESULTS: Dissatisfaction at baseline (life satisfaction score=12-20) was associated with a higher risk of suicide throughout the 20-year follow-up period (age-adjusted hazard ratio=3.02, 95% confidence interval CI=1.83-4.98). The association was somewhat stronger in the first decade (hazard ratio=4.46, 95% CI=1.95-10.20) than in the second (hazard ratio=2.34, 95% CI=1.24-4.45). A dose-response relationship was also found. Men with the highest degrees of dissatisfaction (life satisfaction score=19-20) were 24.85 times as prone to commit suicide as satisfied men during the first 10 years of the follow-up period. Throughout the entire follow-up, life dissatisfaction still predicted suicide after adjusting for age, sex, baseline health status, alcohol consumption, smoking status, and physical activity (hazard ratio=1.74, 95% CI=1.02-2.97). Subjects who reported dissatisfaction at baseline and again 6 years later showed a high suicide risk (hazard ratio=6.84, 95% CI=1.99-23.50) compared to those who repeatedly reported satisfaction. CONCLUSIONS: Life dissatisfaction has a long-term effect on the risk of suicide, and this seems to be partly mediated through poor health behavior. Life satisfaction seems to be a composite health indicator.
Exercise behavior, cardiorespiratory fitness, and obesity are strongly influenced by genetic factors. By studying young adult twins, we examined to what extent these interrelated traits have shared ...genetic and environmental etiologies. We studied 304 twin individuals selected from the population-based FinnTwin16 study. Physical activity was assessed with the Baecke questionnaire, yielding three indexes: sport index, leisure-time index, and work index. In this study, we focused on sport index, which describes sports participation. Body composition was determined using dual-energy X-ray absorptiometry and cardiorespiratory fitness using a bicycle ergometer exercise test with gas exchange analysis. The Baecke sport index was associated with high maximal oxygen uptake adjusted for lean body mass (Vo(2max)adj) (r = 0.40), with low body fat percentage (BF%) (r = -0.44) and low waist circumference (WC) (r = -0.29). Heritability estimates for the key traits were as follows: 56% for sport index, 71% for Vo(2max)adj, 77% for body mass index, 66% for WC, and 68% for BF%. The association between sport index and Vo(2max) was mostly explained by genetic factors (70%), as were both the association between sport index and BF% (71%) and that between sport index and WC (59%). Our results suggest that genetic factors explain a considerable part of the associations between sports participation, cardiorespiratory fitness, and obesity.
Abstract Background To study whether persistent leisure-time physical activity (PA) during adulthood predicts use of antidepressants later in life. Methods 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). Results 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). Limitations Self-reported physical activity and low number of discordant MZ pairs. Discussion 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.
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