title: Changes in body composition in women over six years at midlife: ovarian and chronological aging.
abstract: BACKGROUND
  Understanding the menopause association with body weight is important because excess weight increases risk for stroke, incident cardiovascular disease, cardiovascular mortality, and all-cause mortality among the middle-aged.
  
  
  OBJECTIVE
  The objective of this study was to examine chronological age and ovarian age and consider how these could influence body size and composition in midlife women.
  
  
  METHODS
  The Study of Women's Health Across the Nation is a longitudinal, community-based study. This report uses data from the Michigan Study of Women's Health Across the Nation site.
  
  
  METHODS
  Participants were 543 premenopausal or early perimenopausal African-American and Caucasian women aged 42-52 yr at baseline examination.
  
  
  METHODS
  Waist circumference, fat mass and skeletal muscle mass, from bioelectrical impedance, were assessed in seven annual serial measures. Annual FSH values were assayed by ELISA. The final menstrual period was defined retrospectively after 12 months of amenorrhea.
  
  
  RESULTS
  There was an absolute cumulative 6-yr increase in fat mass of 3.4 kg and a 6-yr decrease in skeletal muscle mass of approximately 0.23 kg. There was an absolute cumulative 6-yr increase of approximately 5.7 cm in waist circumference. The (log)FSH change was positively correlated with (log)(fat mass) change. Waist circumference increased over the time period, but 1 yr after final menstrual period, the rate of increase slowed. Fat mass continued to increase with no change in rate.
  
  
  CONCLUSIONS
  Both time (chronological aging) and ovarian aging contributed to substantial changes in body composition (fat and skeletal muscle mass) and waist circumference. These changes have important ramifications for establishing a metabolic environment that can be healthy or unhealthy.
authors.affiliation: Department of Epidemiology, School of Public Health, University of Michigan, 339 East Liberty Street, Suite 310, Ann Arbor, Michigan 48104, USA. mfsowers@umich.edu
authors.forename: MaryFran
authors.initials: M
authors.lastname: Sowers
authors.forename: Huiyong
authors.initials: H
authors.lastname: Zheng
authors.forename: Kristin
authors.initials: K
authors.lastname: Tomey
authors.forename: Carrie
authors.initials: C
authors.lastname: Karvonen-Gutierrez
authors.forename: Mary
authors.initials: M
authors.lastname: Jannausch
authors.forename: Xizhao
authors.initials: X
authors.lastname: Li
authors.forename: Matheos
authors.initials: M
authors.lastname: Yosef
authors.forename: James
authors.initials: J
authors.lastname: Symons
mesh_terms: D000328:Adult; D000375:Aging / Q000208:ethnology / Q000502:physiology*; D001823:Body Composition; D050218:Body Fat Distribution; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D008593:Menopause / Q000502:physiology; D008598:Menstruation; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000033:anatomy & histology; D009929:Organ Size; D010053:Ovary / Q000502:physiology*; D049629:Waist-Hip Ratio
chemical_list: D005640:Follicle Stimulating Hormone