title: The longitudinal relation between smoking and muscle strength in healthy adults.
abstract: OBJECTIVE
  To assess longitudinally whether smoking tobacco is related to muscle strength in healthy adults and to assess the influence of lifestyle covariates on this relation.
  
  
  METHODS
  Data were obtained from the observational Amsterdam Growth and Health Longitudinal Study, with four repeated measurements at the ages of 21 (n = 181), 27 (n = 144), 32 (n = 426) and 36 (n = 373) years. Knee muscle strength (KMS) was measured at an angle of 300° per second. Smoking and the covariates physical activity and dietary intake were assessed with a questionnaire. Other covariates included physical fitness and body fat percentage. Cardiopulmonary fitness was assessed with a maximal running test and body fatness with skinfold measurements. Sex-specific longitudinal analyses were carried out using generalized estimating equations.
  
  
  RESULTS
  In men and women, an inverse relationship between smoking tobacco and KMS was found. Smoking 100 g of tobacco a week resulted in a reduction of 2.9% in KMS in men and a reduction of 5.0% in women. This relation existed largely independently of lifestyle covariates.
  
  
  CONCLUSIONS
  This study indicates that smoking is inversely related to skeletal muscle strength in healthy adults.
authors.affiliation: Department of Health Sciences and the EMGO Institute of Health and Care Research, Faculty of Earth and Life Sciences, VU University, Amsterdam, The Netherlands.
authors.forename: Maarten O
authors.initials: MO
authors.lastname: Kok
authors.forename: Trynke
authors.initials: T
authors.lastname: Hoekstra
authors.forename: Jos W R
authors.initials: JW
authors.lastname: Twisk
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects; D000328:Adult; D004032:Diet; D005080:Exercise Test; D005260:Female; D006801:Humans; D008019:Life Style; D008137:Longitudinal Studies; D008297:Male; D009043:Motor Activity; D053580:Muscle Strength / Q000187:drug effects*; D009426:Netherlands; D010809:Physical Fitness; D012737:Sex Factors; D012885:Skinfold Thickness; D012907:Smoking / Q000009:adverse effects*; D011795:Surveys and Questionnaires; D055815:Young Adult