Gender differences in development of mental well-being from adolescence to young adulthood: an eight-year follow-up study.

BACKGROUND: The transition from adolescence to young adulthood is marked by many changes. Mental well-being plays an important role in how individuals deal with these changes and how they develop their lifestyle. The goal of this study was to examine gender differences in the long-term development of self-esteem and other mental well-being variables from the age of 15 to the age of 23. METHODS: A baseline measurement was performed in a nationwide sample of 385 Icelandic adolescents aged 15, and a follow-up measurement was conducted eight years later, when participants had reached the age of 23. Standardized questionnaires were used to measure self-reports of self-esteem, life satisfaction, body image, anxiety, depression and somatic complaints. RESULTS: Women improved their self-esteem significantly more than men from the age of 15 to 23 (p=0.004). Women were more satisfied with their life than men at the age of 23 (p=0.009). Men had a better body image, less anxiety, less depression and fewer somatic complaints than women, independent of age. Across gender, anxiety declined and somatic complaints became fewer (p<0.05). CONCLUSIONS These findings suggest that gender differences in mental well-being factors, favouring men, found in adolescents, are not as long-lasting as previously thought. Women improve their mental well-being from adolescence to young adulthood while men's mental well-being does not change.

Midlife determinants associated with sedentary behavior in old age.

BACKGROUND: Sedentary behavior is associated with adverse health effects. Insights into associated determinants are essential to prevent sedentary behavior and limit health risks. Sedentary behavior should be viewed as a distinct health behavior; therefore, its determinants should be independently identified. PURPOSE: This study examines the prospective associations between a wide range of midlife determinants and objectively measured sedentary time in old age. METHODS: Data from 565 participants (age 73-92 yr) of the AGESII-Reykjavik Study were used. Participants wore an accelerometer (ActiGraph GT3X) on the right hip for seven consecutive days. On average, 31 yr earlier (during midlife), demographic, socioeconomic, lifestyle, and biomedical factors were collected. Linear regression models were used to examine prospective associations between midlife determinants and sedentary time (<100 counts per minute) in old age. RESULTS: After adjustment for sex, age, follow-up time, minutes of moderate to vigorous physical activity, body mass index, health status, mobility limitation, and joint pain in old age, the midlife determinants not being married, primary education, living in a duplex or living in an apartment (vs villa), being obese, and having a heart disease were associated with, on average, 15.3, 12.4, 13.5, 13.3, 21.8, and 38.9 sedentary minutes more per day in old age, respectively. CONCLUSIONS: This study shows that demographic, socioeconomic, and biomedical determinants in midlife were associated with considerably more sedentary time per day in old age. These results can indicate the possibility of predicting sedentariness in old age, which could be used to identify target groups for prevention programs reducing sedentary time in older adults.

Is there a sex difference in accelerometer counts during walking in older adults?

BACKGROUND: Accelerometers have emerged as a useful tool for measuring free-living physical activity in epidemiological studies. Validity of activity estimates depends on the assumption that measurements are equivalent for males and females while performing activities of the same intensity. The primary purpose of this study was to compare accelerometer count values in males and females undergoing a standardized 6-minute walk test. METHODS: The study population was older adults (78.6 ± 4.1 years) from the AGES-Reykjavik Study (N = 319). Participants performed a 6-minute walk test at a self-selected fast pace while wearing an ActiGraph GT3X at the hip. Vertical axis counts · s(-1) was the primary outcome. Covariates included walking speed, height, weight, BMI, waist circumference, femur length, and step length. RESULTS: On average, males walked 7.2% faster than females (1.31 vs. 1.22 m · s(-1), P < .001) and had 32.3% greater vertical axis counts · s(-1) (54.6 vs. 39.4 counts · s(-1), P < .001). Accounting for walking speed reduced the sex difference to 19.2% and accounting for step length further reduced the difference to 13.4% (P < .001). CONCLUSION: Vertical axis counts · s(-1) were disproportionally greater in males even after adjustment for walking speed. This difference could confound free-living activity estimates.

Assessment of a two-year school-based physical activity intervention among 7-9-year-old children.

BACKGROUND: Physical activity (PA) in children has declined in recent decades, highlighting the need for effective intervention programs for school-aged children. The main objective of this study was to assess to what extent PA during and after school hours changed among children who received a progressive two-year long intervention vs. that of children who only received general curriculum-based PA. METHODS: A cluster randomized intervention study was conducted and six elementary schools randomly assigned to serve as control- or intervention schools. All children attending second grade (mean age = 7.4 years - born in 1999) were invited to participate in the fall of 2006 (N = 320, 82% participated), again in 2007 (midpoint) and 2008 (end of intervention). The intervention consisted of multi-component PA-intervention during school hours and was conducted by teachers at each intervention school. PA was assessed by means of accelerometers and subjectively at the intervention schools via teachers' PA log-books. RESULTS: There was no difference in PA intensity (minutes of moderate-to-vigorous physical activity - min of MVPA) between the two study groups at baseline, but children in the intervention schools were more physically active at moderate-to-vigorous intensity compared to those in control schools after one year of intervention (mean difference of MVPAlog-minutes: 0.61, 95%CI: 0.02, 1.20, p = 0.04). Moreover, the model for minutes of MVPA during school hours, showed a significant three-way interaction between time at mid-point, group and gender (mean difference of MVPAlog-minutes: 1.06, 95%CI: 0.15, 1.97, p = .02), indicating a significantly greater increase among the boys in the intervention schools compared to girls. No difference in PA was detected between the study groups at the end of the study period after two years of intervention. CONCLUSIONS: The results suggest that the objective of increasing PA at school was met after one year of intervention, and it was more pronounced among boys. The lack of increase at the end of the study period suggested that any increase in PA during school may highly depend on both motivation and training of general teachers. Boys may respond better to PA interventions such as the one described in this study.