• Are pro-inflammatory markers associated with psychological distress in a cross-sectional study of healthy adolescents 15–17 years of age? The Fit Futures study 

      Linkas, Jonas; Ahmed, Luai A.; Csifcsak, Gabor; Emaus, Nina; Furberg, Anne-Sofie; Grimnes, Guri; Pettersen, Gunn; Rognmo, Kamilla; Christoffersen, Tore (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-03-15)
      Background - Inflammatory markers have been associated with depression and anxiety disorder in adolescents. Less is known about the association between inflammation and subclinical symptoms in the form of psychological distress. We investigated prevalence of psychological distress and examined the associations between common pro-inflammatory markers and psychological distress in an adolescent ...
    • The association between childhood fractures and adolescence bone outcomes: a population-based study, the Tromsø Study, Fit Futures 

      Christoffersen, Tore; Emaus, Nina; Dennison, Elaine; Furberg, Anne-Sofie; Gracia-Marco, Luis; Grimnes, Guri; Nilsen, Ole-Andreas; Vlachopoulos, Dimitris; Winther, Anne; Ahmed, Luai A. (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-11-16)
      <p><i>SUMMARY</i>: Childhood fracture may predict persistent skeletal fragility, but it may also reflect high physical activity which is beneficial to bone development. We observe a difference in the relationship between previous fracture and bone outcome across physical activity level and sex. Further elaboration on this variation is needed.</p> <p><i>PURPOSE</i>: Childhood fracture may be an ...
    • Body weight and body mass index influence bone mineral density in late adolescence in a two-year follow-up study. The Tromsø Study: Fit Futures 

      Nilsen, Ole Andreas; Ahmed, Luai A.; Winther, Anne; Christoffersen, Tore; Thrane, Gyrd; Evensen, Elin; Furberg, Anne-Sofie; Grimnes, Guri; Dennison, Elaine; Emaus, Nina (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-04-04)
      Determinants of bone acquisition in late adolescence and early adulthood are not well‐described. This 2‐year follow‐up study explored the associations of body weight (BW), body mass index (BMI), and changes in weight status with adolescent bone accretion in a sample of 651 adolescents (355 girls and 296 boys) between 15 and 19 years of age from The Tromsø Study: Fit Futures. This Norwegian ...
    • Bone mineral density at the hip and its relation to fat mass and lean mass in adolescents: the Tromsø Study, Fit Futures 

      Winther, Anne; Jørgensen, Lone; Ahmed, Luai A.; Christoffersen, Tore; Furberg, Anne-Sofie; Grimnes, Guri; Jorde, Rolf; Nilsen, Ole-Andreas; Dennison, Elaine M.; Emaus, Nina (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-01-19)
      <p><i>Background</i>: Positive association between body weight and bone mass is well established, and the concept of body mass index (BMI) is associated with higher areal bone mineral density (aBMD) and reduced fracture risk. BMI, that comprises both fat mass (FM) and lean mass (LM) may contribute to peak bone mass achievement in different ways. This study explored the influence of body composition ...
    • C-Reactive Protein and TGF-α Predict Psychological Distress at Two Years of Follow-Up in Healthy Adolescent Boys: The Fit Futures Study 

      Linkas, Jonas; Ahmed, Luai A.; Csifcsak, Gabor; Emaus, Nina; Furberg, Anne-Sofie; Grimnes, Guri; Pettersen, Gunn; Rognmo, Kamilla; Christoffersen, Tore (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-03-11)
      Objective: The scarcity of research on associations between inflammatory markers and symptoms of depression and anxiety during adolescence has yielded inconsistent results. Further, not all studies have controlled for potential confounders. We explored the associations between baseline inflammatory markers and psychological distress including moderators at follow-up in a Norwegian adolescent population ...
    • Changes and tracking of bone mineral density in late adolescence: the Tromsø Study, Fit Futures 

      Nilsen, Ole Andreas; Ahmed, Luai A.; Winther, Anne; Christoffersen, Tore; Furberg, Anne-Sofie; Grimnes, Guri; Dennison, Elaine; Emaus, Nina (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-04-08)
      <p><i>Summary</i>: Areal bone mineral density (aBMD) predicts future fracture risk. This study explores the development of aBMD and associated factors in Norwegian adolescents. Our results indicate a high degree of tracking of aBMD levels in adolescence. Anthropometric measures and lifestyle factors were associated with deviation from tracking.</p> <p><i>Purpose</i>: Norway has one of the highest ...
    • Criterion validity of the Saltin-Grimby Physical Activity Level Scale in adolescents. The Fit Futures Study 

      Beldo, Sigurd Klemetsen; Aars, Nils Abel; Christoffersen, Tore; Furberg, Anne-Sofie; Halvorsen, Peder Andreas; Hansen, Bjørge Hermann; Horsch, Alexander; Sagelv, Edvard Hamnvik; Syed, Shaheen; Morseth, Bente (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-09-01)
      Background<p> <p>The Saltin-Grimby Physical Activity Level Scale (SGPALS) is commonly used to measure physical activity (PA) in population studies, but its validity in adolescents is unknown. This study aimed to assess the criterion validity of the SGPALS against accelerometry in a large sample of adolescents. A secondary aim was to examine the validity across strata of sex, body mass index (BMI), ...
    • Does the frequency and intensity of physical activity in adolescence have an impact on bone? The Tromsø Study, Fit Futures 

      Christoffersen, Tore; Winther, Anne; Nilsen, Ole-Andreas; Ahmed, Luai Awad; Furberg, Anne-Sofie; Grimnes, Guri; Dennison, Elaine; Emaus, Nina (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-10)
      Background: Optimization of the genetic potential for bone accrual in early life may prevent future fractures. Possible modification factors include lifestyle factors such as nutrition and physical activity. Measured levels of bone mineral density (BMD) and bone mass content (BMC) are indicators of bone strength, and are correlated with fracture risk. This study explored the impact of self-reported ...
    • Effect of maturational timing on bone health in male adolescent athletes engaged in different sports: The PRO-BONE study 

      Ubago-Guisado, Esther; Vlachopoulos, Dimitris; Barker, Alan R; Christoffersen, Tore; Metcalf, Brad; Gracia-Marco, Luis (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-08-18)
      <p><i>Objectives</i>: To describe differences in bone outcomes according to biological age in male athletes participating in osteogenic (OS) or non-osteogenic (NOS) sports.</p> <p><i>Design</i>: Longitudinal (12-months).</p> <p><i>Methods</i>: 104 adolescents (12–14 years) were measured at baseline and after 1y: OS group (n = 37 football or soccer players) and NOS group (n = 39 swimmers, n = ...
    • Fracture incidence rates in Norwegian children, The Tromsø Study, Fit Futures 

      Christoffersen, Tore; Ahmed, Luai Awad; Winther, Anne; Nilsen, Ole-Andreas; Furberg, Anne-Sofie; Grimnes, Guri; Dennison, Elaine; Center, Jacqueline R; Eisman, John A.; Emaus, Nina (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-12-08)
      Summary: <br> This study describes childhood fracture rates in Norway, a country known for high fracture rates in the adult population. Fracture rates correspond with other reports from Scandinavia, although with a slightly higher proportion in girls. Indications of increased vulnerability during stages of puberty require further exploration. <p>Introduction: Fractures are common injuries during ...
    • How Is Adolescent Bone Mass and Density Influenced by Early Life Body Size and Growth? The Tromsø Study: Fit Futures—A Longitudinal Cohort Study From Norway 

      Evensen, Elin; Skeie, Guri; Wilsgaard, Tom; Christoffersen, Tore; Dennison, Elaine; Furberg, Anne-Sofie; Grimnes, Guri; Winther, Anne; Emaus, Nina (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-03-30)
      The effect of birth weight and childhood body mass index (BMI) on adolescents’ bone parameters is not established. The aim of this longitudinal, population‐based study was to investigate the association of birth weight, childhood BMI, and growth, with adolescent bone mass and bone density in a sample of 633 adolescents (48% girls) from The Tromsø Study: Fit Futures. This population‐based cohort study ...
    • The influence of birth weight and length on bone mineral density and content in adolescence: The Tromsø Study, Fit Futures 

      Christoffersen, Tore; Ahmed, Luai A.; Daltveit, Anne Kjersti; Dennison, Elaine; Evensen, Elin; Furberg, Anne-Sofie; Gracia-Marco, Luis; Grimnes, Guri; Nilsen, Ole-Andreas; Schei, Berit; Tell, Grethe S.; Vlachopoulous, Dimitris; Winther, Anne; Emaus, Nina (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-06-02)
      <p><i>Summary</i> The influence of birth weight and length on bone mineral parameters in adolescence is unclear. We found a positive association between birth size and bone mineral content, attenuated by lifestyle factors. This highlights the impact of environmental stimuli and lifestyle during growth.</p> <p><i>Purpose</i> The influence of birth weight and length on bone mineral density and ...
    • The influence of birth weight, childhood fractures and lifestyle factors on peak bone mass in Norwegian boys and girls between 15-18 years of age. The Tromsø Study, Fit Futures 

      Christoffersen, Tore (Doctoral thesis; Doktorgradsavhandling, 2017-11-22)
      The basis of bone strength is created during early development and growth, before the achievement and consolidation of a peak bone mass (PBM) in the second or early third decade of life. In order to optimize PBM, we need to identify modifiable predictors that influence bone mass accrual during growth and the vulnerable period of adolescence. The main aim of this thesis was to investigate the ...
    • The influence of snuff and smoking on bone accretion in late adolescence. The Tromsø study, Fit Futures 

      Nilsen, Ole-Andreas; Emaus, Nina; Christoffersen, Tore; Winther, Anne; Evensen, Elin; Thrane, Gyrd; Furberg, Anne-Sofie; Grimnes, Guri; Ahmed, Luai A. (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-09-27)
      Summary - Areal bone mineral density (aBMD) predicts future fracture risk. This study explores associations between use of tobacco and bone accretion in Norwegian adolescents. Our results indicate that use of snuff is negatively associated with accretion of aBMD in adolescence and may be a signal of increased future fracture risk.<p> <p>Purpose - Bone mineral accrual in childhood and adolescence ...
    • Our health, our research. Identifying public health research priorities among children and youth in a multiethnic population: Protocol for a community-based participatory health research priority survey 

      Irgens, Eirik Lind; Berglen, Gunnhild; Christoffersen, Tore; Henninen, Anita Pettersen; Hermansen, Rune Hermann; Karlsen, Maret Risten Eira; Kokkvoll, Ane Sofie; Liabo, Kristin; Møllersen, Snefrid; Rugland, Grete; Stock, Magnhild Helen; Zachariassen, Tonje Olsen; Kjær, Mette (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-07-19)
      Introduction Emphasis on public involvement (PI) in health research has increased in the last 20 years. However, there is limited literature on PI in planning and conducting population-based health research. This study aims to identify child and adolescent health research priorities among children and stakeholder groups in Northern Norway by inviting PI groups to collaborate with researchers ...
    • Prevalence of accelerometer-measured physical activity in adolescents in Fit Futures – part of the Tromsø Study 

      Beldo, Sigurd; Morseth, Bente; Christoffersen, Tore; Halvorsen, Peder Andreas; Hansen, Bjørge Hermann; Furberg, Anne-Sofie; Ekelund, Ulf; Horsch, Alexander (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-07-17)
      <i>Background</i> - Previous studies show large variations in physical activity (PA) levels among adolescents. However, the number of studies is limited and even fewer studies have assessed PA in adolescents by accelerometer devices. This study aimed to describe accelerometer-measured PA levels in adolescents in a population-based cohort in Northern Norway.<p> <p><i>Methods</i> - In 611 students ...
    • Two-year changes in sleep duration are associated with changes in psychological distress in adolescent girls and boys: the fit futures study 

      Linkas, Jonas; Ahmed, Luai Awad; Csifcsak, Gabor; Emaus, Nina; Furberg, Anne-Sofie; Pettersen, Gunn; Rognmo, Kamilla; Christoffersen, Tore (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-11-21)
      <p><i>Objective -</i> Studies indicate an inverse association between sleep duration and psychological distress. We aimed to explore associations between changes in sleep duration and changes in psychological distress in girls and boys. <p><i>Methods -</i> The Fit Futures Study is a broad adolescent study providing data from 373 girls and 294 boys aged 15–18 years collected in 2010/2011 (FF1) and ...