Body mass index, fitness and physical activity from childhood through adolescence

1. Katja Pahkala1,2, 
2. Miika Hernelahti2, 
3. Olli J Heinonen2, 
4. Päivi Raittinen3, 
5. Maarit Hakanen1,
6. Hanna Lagström4, 
7. Jorma S A Viikari5, 
8. Tapani Rönnemaa5, 
9. Olli T Raitakari1,6, 
10. Olli Simell1,

Abstract

Background Obesity, sedentary lifestyle and poor cardiorespiratory fitness in childhood may increase the risk of health problems later in life.

Purpose The authors studied the association of early childhood weight status with cardiorespiratory fitness and leisure-time physical activity (LTPA) in adolescence. The stability and associations of LTPA and fitness from childhood through adolescence were also studied.

Methods Body mass index (BMI) was assessed annually since birth in a prospective, longitudinal study. The mean BMI between ages 2 and 7 years indicated weight status at preschool age. Fitness was studied with a shuttle run test at age 9 and with a maximal cycle ergometer test at age 17. The same questionnaire was used to assess LTPA at age 9, 13 and 17. Complete data on preschool BMI, LTPA at ages 13 and 17 and fitness at age 17 years was provided by 351 children, while fitness and LTPA data were available for 74 children at ages 9 and 17.

Results Preschool BMI was inversely associated with fitness in adolescence independently of adolescent LTPA (p=0.0001). Children who had a high preschool BMI but whose weight status was reduced in adolescence had similar fitness in adolescence as the children with a persistently low BMI. Regardless of the fitness level in childhood, the children whose LTPA increased between age 9 and 17 had a similar adolescent fitness level as persistently active subjects.

Conclusions It is important to maintain a healthy body weight and a physically active lifestyle from very childhood through adolescence to improve fitness during adolescence.

http://bjsm.bmj.com/content/47/2/71.full

Cardiorespiratory Fitness, LDL Cholesterol, and CHD Mortality in Men

FARRELL, STEPHEN W.¹; FINLEY, CARRIE E.¹; GRUNDY, SCOTT M.²

Abstract

Introduction: There are no published data regarding the joint association of cardiorespiratory fitness (CRF) and LDL cholesterol concentration with subsequent CHD mortality in men.

Methods: A total of 40,718 healthy men received a comprehensive baseline clinical examination between 1971 and 2006. CRF was determined from a maximal treadmill exercise test. Participants were divided into categories of low (quintile 1), moderate (quintiles 2–3), and high (quintiles 4–5) CRF by age group, as well as by Adult Treatment Panel III–defined LDL categories. HRs for CHD mortality were computed with Cox regression analysis.

Results: A total of 557 deaths due to CHD occurred during 16.7 ± 9.0 yr (681,731 man-years) of follow-up. After adjustment for age, examination year, smoking status, family history, and body mass index, a significant positive trend in CHD mortality was shown across decreasing categories of CRF. HRs with 95% confidence interval were 1.0 (referent), 1.18 (0.94–1.47), and 2.10 (1.65–2.67) for high, moderate, and low fit groups, P trend <0.0001. Adjusted HRs were significantly higher across increasing LDL categories: 1.0 (referent), 1.30 (0.87–1.95), 1.54 (1.04–2.28), 2.16 (1.45–3.21), and 2.02 (1.31–3.13), P trend <0.0001. When grouped by CRF category as well as by LDL category, there was a significant positive trend (P < 0.02) in adjusted mortality across decreasing categories of CRF within each LDL category.

Conclusions: CRF is strongly and inversely associated with CHD mortality in men. Compared with men with low CRF, at a moderate to high level of CRF, the risk of mortality within each LDL category is significantly attenuated. This study suggests that measurement of CRF should be considered for routine cardiovascular risk assessment and risk management.

http://journals.lww.com/acsm-msse/Fulltext/2012/11000/Cardiorespiratory_Fitness,_LDL_Cholesterol,_and.12.aspx?WT.mc_id=EMxj18x20121226ACSMHTxL4