Cardiorespiratory Fitness and Risk of Fatty Liver: The Young Finns Study.

PURPOSE: Fatty liver is an expanding health concern associated with metabolic disturbances and increased risk of cardiovascular disease. Experimental studies in animals have shown associations between fatty liver and cardiorespiratory fitness but limited data exist in humans. The aim of this study was to analyze the links between cardiorespiratory fitness and fatty liver in a population-based sample of adults. METHODS: Participants were 463 adults (48% men) from the Cardiovascular Risk in Young Finns Study. Cardiorespiratory fitness was measured with a cycle ergometer exercise test as peak oxygen uptake (V˙O2peak [mL·kg·min]) in 2008 to 2009. Hepatic ultrasonographic imaging was performed in 2011 to determine fatty liver. RESULTS: Cardiorespiratory fitness was associated with lower risk of fatty liver (1 mL·kg·min increase in V˙O2peak: risk ratio, 0.90; 95% confidence interval, 0.88-0.93, P < 0.0001; adjusted for age and sex). This association remained significant after further adjustments with physical activity, adiposity, smoking, alcohol consumption, serum lipids, insulin, glucose, and C-reactive protein. Participants who were obese (waist circumference, >80 cm in women and >94 cm in men) but fit (V˙O2peak in the upper age- and sex-specific median) had lower prevalence of fatty liver than participants who were obese and unfit (below median), (11.7% vs 34.8%, P = 0.0003). CONCLUSIONS: In a population-based sample of adults, cardiorespiratory fitness is strongly, inversely and independently related with the risk of fatty liver. Importantly, the association is evident also among obese.

Childhood predictors of adult fatty liver. The Cardiovascular Risk in Young Finns Study.

BACKGROUND & AIMS: Fatty liver is a potentially preventable cause of serious liver diseases. This longitudinal study aimed to identify childhood risk factors of fatty liver in adulthood in a population-based group of Finnish adults. METHODS: Study cohort included 2,042 individuals from the Cardiovascular Risk in Young Finns Study aged 3-18years at baseline in 1980. During the latest follow-up in 2011, the liver was scanned by ultrasound. In addition to physical and environmental factors related to fatty liver, we examined whether the genetic risk posed by a single nucleotide polymorphism in the patatin-like phospholipase domain-containing protein 3 gene (PNPLA3) (rs738409) strengthens prediction of adult fatty liver. RESULTS: Independent childhood predictors of adult fatty liver were small for gestational age, (odds ratio=1.71, 95% confidence interval=1.07-2.72), variant in PNPLA3 (1.63, 1.29-2.07 per one risk allele), variant in the transmembrane 6 superfamily 2 gene (TM6SF2) (1.57, 1.08-2.30), BMI (1.30, 1.07-1.59 per standard deviation) and insulin (1.25, 1.05-1.49 per standard deviation). Childhood blood pressure, physical activity, C-reactive protein, smoking, serum lipid levels or parental lifestyle factors did not predict fatty liver. Risk assessment based on childhood age, sex, BMI, insulin levels, birth weight, TM6SF2 and PNPLA3 was superior in predicting fatty liver compared with the approach using only age, sex, BMI and insulin levels (C statistics, 0.725 vs. 0.749; p=0.002). CONCLUSIONS: Childhood risk factors on the development of fatty liver were small for gestational age, high insulin and high BMI. Prediction of adult fatty liver was enhanced by taking into account genetic variants in PNPLA3 and TM6SF2 genes. LAY SUMMARY: The increase in pediatric obesity emphasizes the importance of identification of children and adolescents at high risk of fatty liver in adulthood. We used data from the longitudinal Cardiovascular Risk in Young Finns Study to examine the associations of childhood (3-18years) risk variables with fatty liver assessed in adulthood at the age of 34-49years. The findings suggest that a multifactorial approach with both lifestyle and genetic factors included would improve early identification of children with a high risk of adult fatty liver.

Does strenuous leisure time physical activity prevent severe back disorders leading to hospitalization?

STUDY DESIGN: Prospective cohort study. OBJECTIVE: To study the associations between strenuous leisure time physical activity (LTPA) and subsequent hospitalization due to back disorders. Socioeconomic and lifestyle factors are associated with back-related hospitalization, but the significance of strenuous LTPA in the working population is unclear. METHODS: The cohort (n = 902) was drawn from among employees in the metal industry (n = 2,653). Data were collected by a questionnaire and a structured interview on LTPA. Activity regarding strenuous (>500 kcal/h) LTPA was categorized as none, some, and high. Information from national registers on hospitalizations and deaths during 28 years of follow-up was linked to the data. Cox proportional hazards regression was used. RESULTS: Subjects with a high level of strenuous LTPA had a decreased risk of hospitalization due to back disorders (hazard ratio 0.40; 95% CI 0.21-0.79) compared with persons with no strenuous activity, after adjustment for age and gender. The association persisted (0.48; 0.24-0.96) when further adjusted for occupational class, self-reported back diseases, smoking, and body mass index at baseline. CONCLUSION: Strenuous LTPA decreased the risk of inpatient hospital care for back disorders among industrial employees.

Leadership component of type A behavior predicts physical activity in early midlife.

BACKGROUND: Research on the long-term effects of Type A behavior and its components in the prediction of physical activity in adulthood is scarce and there is a lack of prospective data that are able to show such an association. PURPOSE: We examined the relations between components of Type A behavior and physical activity from youth to early midlife. METHOD: The sample included 2,031 participants (43.8% of males) aged 9 to 24 years in 1986 from the Young Finns Study. Type A behavior was measured by the Hunter-Wolf A-B Rating Scale at three phases in 1986, 1989, and 2001. Physical activity was assessed using a short self-report questionnaire at five phases between 1986 and 2007. RESULTS: High Type A leadership was associated with high physical activity in 1986 (r = 0.37, P < 0.01), 1989 (r = 0.36, P < 0.01) and 2001 (r = 0.31, P < 0.01), and youth leadership also predicted high adult physical activity (P < 0.001). After adjustment for age, education, occupation, smoking, body mass index, and baseline physical activity, the association remained significant. There was also a bidirectional association between Type A leadership and physical activity. Persistent physical activity during the adult years was associated with a higher Type A leadership than persistent physical inactivity (Cohen's d = 0.34, P < 0.001), even after controlling for potential confounders. The associations of other components of Type A behavior, i.e., hard-driving, eagerness-energy, and aggression with physical activity were marginal. CONCLUSION: There is a direct relation between Type A leadership and physical activity at different development phases that maybe bidirectional.

Cross-sectional associations between physical activity and selected coronary heart disease risk factors in young adults. The Cardiovascular Risk in Young Finns Study.

OBJECTIVE: Physical activity (PA) may reduce the risk of coronary heart disease (CHD) by inducing beneficial changes in several risk factors. We studied the associations between PA and a range of risk markers of CHD in young adults. METHODS AND RESULTS: We measured serum lipoproteins, oxidized LDL, adipokines, inflammatory markers, metabolic markers, and arginine metabolites in 2,268 individuals (age 24-39 y). Participants were asked frequency, duration, and intensity of PA in leisure time. In addition, commuting to work was assessed. In both sexes, PA was inversely associated with waist circumference (all P < 0.0001). After controlling for sex, age, and waist circumference, PA was directly associated with HDL-cholesterol and apolipoprotein A1, and inversely with heart rate, smoking, oxidized LDL, apolipoprotein B, insulin, glucose, C-reactive protein, leptin, L-arginine, and phospholipase A2 activity (all P < 0.05). CONCLUSION: These population-based data are consistent with the idea that the beneficial effects of PA on CHD risk are mediated by favorable influences on several risk factors, as judged by independent relations to markers of lipoprotein metabolism, glucose metabolism, and inflammation. These associations reflect beneficial effects on cardiovascular health in both sexes and may offer mechanistic insights for the inverse association between PA and CHD.

Life-time risk factors and progression of carotid atherosclerosis in young adults: the Cardiovascular Risk in Young Finns study.

AIMS: The aim of this study is to evaluate whether childhood risk factors are associated with a 6-year change in carotid intima-media thickness (IMT) in young adulthood independent of the current risk factors. METHODS AND RESULTS: The Cardiovascular Risk in Young Finns cohort consisted of 1809 subjects who were followed-up for 27 years since baseline (1980, age 3-18 years) and having carotid IMT measured both in 2001 and 2007. Cardiovascular risk factors were assessed repeatedly since childhood. A genotype risk score was calculated using 17 newly identified genetic variants associating with cardiovascular morbidity. The number of childhood risk factors (high LDL-cholesterol, low HDL-cholesterol, high blood pressure, obesity, diabetes, smoking, low physical activity, infrequent fruit consumption) was associated with a 6-year change in adulthood IMT. In subjects with 0, 1, 2, and > or =3 childhood risk factors, IMT [mean (95% CI)) increased by 35 (28-42), 46 (40-52), 49 (41-57), and 61 (49-73) microm (P = 0.0001). This association remained significant when adjusted for adulthood risk score and genotype score (P = 0.007). Of the individual childhood variables, infrequent fruit consumption ((beta (95% CI) for 1-SD change -5(-9 to -1), P = 0.03) and low physical activity (-6(-10 to -2), P = 0.01) were associated with accelerated IMT progression after taking into account these variables assessed in adulthood. CONCLUSION: These findings indicate that children with risk factors have increased atherosclerosis progression rate in adulthood, and support the idea that the prevention of atherosclerosis by means of life style could be effective when initiated in childhood.

School performance as a predictor of adulthood obesity: a 21-year follow-up study.

We examined the impact of school performance measured in terms of grade point averages (GPAs) in early and middle adolescence (ages 9, 12, and 15), and the impact of school performance throughout the different school stages on adult obesity. The participants were 732 healthy women and men derived from a population-based Cardiovascular Risk in Young Finns Study. GPAs were measured at the ages of 9, 12, and 15. The body mass index (BMI; kg/m(2)), and the waist circumference (WC) were conducted participants being aged 27 or 30. Birth weight, childhood BMI, adulthood physical activity, maternal and paternal BMI, and maternal education were controlled for. The results showed that low GPAs in each measurement and low GPAs throughout the comprehensive school were a risk factor of adulthood obesity, but only among women. The association remained when controlling for potential confounding variables (p-values in the fully adjusted models 0.026, 0.007, and 0.004 at the ages of 9, 12, and 15, respectively). The results were similar when the BMI was used as a dichotomous variable (BMI > or = 30 and BMI < 30). Low school performance has previously been associated with higher rates of smoking and alcohol consumption later in life. Our result underscores that low school performance is a health risk factor that should be taken seriously in preventive health education.

Shift work in young adults and carotid artery intima-media thickness: The Cardiovascular Risk in Young Finns study.

OBJECTIVE: Shift work is associated with an elevated risk of cardiovascular disease, but the timing or mechanisms of this association is unclear. METHODS AND RESULTS: We examined the relationship between shift work and subclinical atherosclerosis in 1543 (712 men and 831 women, 24-39 years old) young adults as part of the ongoing population-based Cardiovascular Risk in Young Finns study. Carotid atherosclerosis was assessed by measuring the thickness of the common carotid artery intima-media (IMT) complex with ultrasound and carotid plaque. Working schedules were categorized as day work or shift work (2- or 3-shift work, regular evening or night work). In men, shift work was associated with higher mean IMT (B=0.029, p=0.021), maximum IMT (B=0.029, p=0.028), and a 2.2-fold odds of carotid plaque (95% CI, 1.2-4.0). These relationships persisted after adjustment for age and risk factors, such as low socio-economic position, job strain, smoking, diet, family history of CHD, physical inactivity, alcohol consumption, obesity, homocysteine, C-reactive protein, blood pressure, and lipids. In women, no association was found between shift work and carotid atherosclerosis indicators. CONCLUSIONS: Our results suggest that shift work accelerates the atherosclerotic process and that the effects of shift work on subclinical atherosclerosis are observable in men already before age 40.

The longitudinal effects of physical activity history on metabolic syndrome.

PURPOSE: To examine the relationship of physical activity and its changes over a 9-yr follow-up to the prevalence of metabolic syndrome (MetS) in 2060 young adults (24-39 yr) enrolled in the Cardiovascular Risk in Young Finns Study. METHODS: Leisure-time physical activity (LTPA) was assessed using a self-report questionnaire completed in connection with a medical examination at two consecutive measurements in 1992 and 2001. By summing the LTPA items, a physical activity index (PAI) was formed for both measurement points according to which the participants were divided into tracking groups: persistently active, increasingly active, decreasingly active, and persistently inactive. MetS in 2001 was defined by the guidelines of the European Group for the Study of Insulin Resistance (EGIR), the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III), and the International Diabetes Federation (IDF). A continuous metabolic risk score was also calculated by summing the z-scores for the metabolic risk factors. RESULTS: There was a significant linear relationship between MetS and LTPA at baseline in men and at follow-up in both sexes according to all three definitions. Persistent physical activity during 9 yr was associated with a lower prevalence of MetS than persistent physical inactivity on all definitions (all P < 0.05). Similar results were found for increasingly active women (all P < 0.05). All of these associations remained significant after adjustment for potential confounders. In both men and women, the 9-yr change in LTPA was related to the metabolic risk score after adjustments for baseline LTPA, age, smoking, and education. CONCLUSIONS: A physically active lifestyle across the lifespan may prevent or delay the onset of metabolic syndrome in young male and female adults.