title: Menopause, Reproductive Life, Hormone Replacement Therapy, and Bone Phenotype at Age 60-64 Years: A British Birth Cohort.
abstract: Previous studies of menopausal age and length of reproductive life on bone are limited by retrospective reproductive histories, being cross-sectional, or lacking gold standard bone technologies or information on hormone replacement therapy (HRT) or surgical treatment.
  
  
  
  The objective of the study was to investigate age at menopause, length of reproductive life, and HRT use in relation to volumetric and areal bone mineral density (vBMD, aBMD), bone size, and strength in women aged 60-64 years.
  
  
  
  This was a birth cohort study that followed up for 64 years with prospective measures of age at menarche and menopause and monthly HRT histories.
  
  
  
  The study was conducted in England, Scotland, and Wales.
  
  
  
  Participants included 848 women with a known type of menopause and bone measures at 60-64 years.
  
  
  
  Peripheral quantitative computed tomography measurements of the distal radius total and trabecular vBMD were measured. Diaphyseal radius total and medullary cross-sectional area, cortical vBMD, and polar strength strain index (SSI); dual-energy x-ray absorptiometry measurements of aBMD at the lumbar spine and total hip were also measured.
  
  
  
  A 10-year increase in age at natural (but not surgical) menopause was associated with 8.2% (95% confidence interval [CI] 1.3%-15.1%, P = .02) greater trabecular vBMD and a 6.0% (95% CI 0.51%-11.5%, P = .03) greater total vBMD; findings were similar for length of reproductive life. A 10-year difference in HRT use was associated with a 6.0% (95% CI 2.6%-9.3%, P < .001) greater polar SSI and a 0.9% (95% CI 0.4%-1.5%, P = .001) greater cortical vBMD. These estimates changed little on adjustment. Estimates for aBMD were consistent with those for peripheral quantitative computed tomography.
  
  
  
  The positive effects on trabecular vBMD of later natural menopause and longer reproductive life persisted into early old age. HRT use was associated with greater radius cortical vBMD and polar SSI and aBMD.
authors.affiliation: Medical Research Council Unit for Lifelong Health and Ageing (D.K., S.M., R.C., A.M., K.M., R.H.), University College London, London WC1B 5JU, United Kingdom; Medical Research Council Lifecourse Epidemiology Unit (C.C., K.A.W.), University of Southampton, Southampton SO16 6YD, United Kingdom; Clinical Radiology and Academic Health Science Centre (J.E.A.), Manchester Royal Infirmary, Central Manchester University Hospital, National Health Service Foundation Trust and University of Manchester, Manchester M13 9PT, United Kingdom; and Medical Research Council Human Nutrition Research (K.A.W.), Cambridge CB1 9NL, United Kingdom.
authors.forename: D
authors.initials: D
authors.lastname: Kuh
authors.affiliation: Medical Research Council Unit for Lifelong Health and Ageing (D.K., S.M., R.C., A.M., K.M., R.H.), University College London, London WC1B 5JU, United Kingdom; Medical Research Council Lifecourse Epidemiology Unit (C.C., K.A.W.), University of Southampton, Southampton SO16 6YD, United Kingdom; Clinical Radiology and Academic Health Science Centre (J.E.A.), Manchester Royal Infirmary, Central Manchester University Hospital, National Health Service Foundation Trust and University of Manchester, Manchester M13 9PT, United Kingdom; and Medical Research Council Human Nutrition Research (K.A.W.), Cambridge CB1 9NL, United Kingdom.
authors.forename: S
authors.initials: S
authors.lastname: Muthuri
authors.affiliation: Medical Research Council Unit for Lifelong Health and Ageing (D.K., S.M., R.C., A.M., K.M., R.H.), University College London, London WC1B 5JU, United Kingdom; Medical Research Council Lifecourse Epidemiology Unit (C.C., K.A.W.), University of Southampton, Southampton SO16 6YD, United Kingdom; Clinical Radiology and Academic Health Science Centre (J.E.A.), Manchester Royal Infirmary, Central Manchester University Hospital, National Health Service Foundation Trust and University of Manchester, Manchester M13 9PT, United Kingdom; and Medical Research Council Human Nutrition Research (K.A.W.), Cambridge CB1 9NL, United Kingdom.
authors.forename: R
authors.initials: R
authors.lastname: Cooper
authors.affiliation: Medical Research Council Unit for Lifelong Health and Ageing (D.K., S.M., R.C., A.M., K.M., R.H.), University College London, London WC1B 5JU, United Kingdom; Medical Research Council Lifecourse Epidemiology Unit (C.C., K.A.W.), University of Southampton, Southampton SO16 6YD, United Kingdom; Clinical Radiology and Academic Health Science Centre (J.E.A.), Manchester Royal Infirmary, Central Manchester University Hospital, National Health Service Foundation Trust and University of Manchester, Manchester M13 9PT, United Kingdom; and Medical Research Council Human Nutrition Research (K.A.W.), Cambridge CB1 9NL, United Kingdom.
authors.forename: A
authors.initials: A
authors.lastname: Moore
authors.affiliation: Medical Research Council Unit for Lifelong Health and Ageing (D.K., S.M., R.C., A.M., K.M., R.H.), University College London, London WC1B 5JU, United Kingdom; Medical Research Council Lifecourse Epidemiology Unit (C.C., K.A.W.), University of Southampton, Southampton SO16 6YD, United Kingdom; Clinical Radiology and Academic Health Science Centre (J.E.A.), Manchester Royal Infirmary, Central Manchester University Hospital, National Health Service Foundation Trust and University of Manchester, Manchester M13 9PT, United Kingdom; and Medical Research Council Human Nutrition Research (K.A.W.), Cambridge CB1 9NL, United Kingdom.
authors.forename: K
authors.initials: K
authors.lastname: Mackinnon
authors.affiliation: Medical Research Council Unit for Lifelong Health and Ageing (D.K., S.M., R.C., A.M., K.M., R.H.), University College London, London WC1B 5JU, United Kingdom; Medical Research Council Lifecourse Epidemiology Unit (C.C., K.A.W.), University of Southampton, Southampton SO16 6YD, United Kingdom; Clinical Radiology and Academic Health Science Centre (J.E.A.), Manchester Royal Infirmary, Central Manchester University Hospital, National Health Service Foundation Trust and University of Manchester, Manchester M13 9PT, United Kingdom; and Medical Research Council Human Nutrition Research (K.A.W.), Cambridge CB1 9NL, United Kingdom.
authors.forename: C
authors.initials: C
authors.lastname: Cooper
authors.affiliation: Medical Research Council Unit for Lifelong Health and Ageing (D.K., S.M., R.C., A.M., K.M., R.H.), University College London, London WC1B 5JU, United Kingdom; Medical Research Council Lifecourse Epidemiology Unit (C.C., K.A.W.), University of Southampton, Southampton SO16 6YD, United Kingdom; Clinical Radiology and Academic Health Science Centre (J.E.A.), Manchester Royal Infirmary, Central Manchester University Hospital, National Health Service Foundation Trust and University of Manchester, Manchester M13 9PT, United Kingdom; and Medical Research Council Human Nutrition Research (K.A.W.), Cambridge CB1 9NL, United Kingdom.
authors.forename: J E
authors.initials: JE
authors.lastname: Adams
authors.affiliation: Medical Research Council Unit for Lifelong Health and Ageing (D.K., S.M., R.C., A.M., K.M., R.H.), University College London, London WC1B 5JU, United Kingdom; Medical Research Council Lifecourse Epidemiology Unit (C.C., K.A.W.), University of Southampton, Southampton SO16 6YD, United Kingdom; Clinical Radiology and Academic Health Science Centre (J.E.A.), Manchester Royal Infirmary, Central Manchester University Hospital, National Health Service Foundation Trust and University of Manchester, Manchester M13 9PT, United Kingdom; and Medical Research Council Human Nutrition Research (K.A.W.), Cambridge CB1 9NL, United Kingdom.
authors.forename: R
authors.initials: R
authors.lastname: Hardy
authors.affiliation: Medical Research Council Unit for Lifelong Health and Ageing (D.K., S.M., R.C., A.M., K.M., R.H.), University College London, London WC1B 5JU, United Kingdom; Medical Research Council Lifecourse Epidemiology Unit (C.C., K.A.W.), University of Southampton, Southampton SO16 6YD, United Kingdom; Clinical Radiology and Academic Health Science Centre (J.E.A.), Manchester Royal Infirmary, Central Manchester University Hospital, National Health Service Foundation Trust and University of Manchester, Manchester M13 9PT, United Kingdom; and Medical Research Council Human Nutrition Research (K.A.W.), Cambridge CB1 9NL, United Kingdom.
authors.forename: K A
authors.initials: KA
authors.lastname: Ward
mesh_terms: D015502:Absorptiometry, Photon; D000367:Age Factors; D015519:Bone Density / Q000502:physiology*; D001842:Bone and Bones / Q000000981:diagnostic imaging*; D004739:England / Q000453:epidemiology; D005260:Female; D020249:Hormone Replacement Therapy / Q000706:statistics & numerical data*; D006801:Humans; D008137:Longitudinal Studies; D008572:Menarche / Q000502:physiology*; D008593:Menopause / Q000502:physiology*; D008875:Middle Aged; D010641:Phenotype; D012606:Scotland / Q000453:epidemiology; D013997:Time Factors; D014852:Wales / Q000453:epidemiology