title: Familial Longevity Is Not Associated with Major Differences in the Hypothalamic-Pituitary-Gonadal Axis in Healthy Middle-Aged Men.
abstract: BACKGROUND
  A trade-off between fertility and longevity possibly exists. The association of the male hypothalamic-pituitary-gonadal (HPG) axis with familial longevity has not yet been investigated.
  
  
  OBJECTIVE
  To study 24-h hormone concentration profiles of the HPG axis in men enriched for familial longevity and controls.
  
  
  METHODS
  We frequently sampled blood over 24 h in 10 healthy middle-aged male offspring of nonagenarian participants from the Leiden Longevity Study together with 10 male age-matched controls. Individual 24-h luteinizing hormone (LH) and testosterone concentration profiles were analyzed by deconvolution analyses to estimate secretion parameters. Furthermore, the temporal relationship between LH and testosterone was assessed by cross-correlation analysis. We used (cross-)approximate entropy to quantify the strength of feedback and/or feedforward control of LH and testosterone secretion.
  
  
  RESULTS
  Mean [95% confidence interval (CI)] total LH secretion of the offspring was 212 (156-268) U/L/24 h, which did not differ significantly (p= 0.51) from the total LH secretion of controls [186 (130-242) U/L/24 h]. Likewise, mean (95% CI) total testosterone secretion of the offspring [806 (671-941) nmol/L/24 h] and controls [811 (676-947) nmol/L/24 h] were similar (p= 0.95). Other parameters of LH and testosterone secretion were also not significantly different between offspring and controls. The temporal relationship between LH and testosterone and the strength of feedforward/feedback regulation within the HPG axis were similar between offspring of long-lived families and controls.
  
  
  CONCLUSIONS
  This relatively small study suggests that in healthy male middle-aged participants, familial longevity is not associated with major differences in the HPG axis. Selection on both fertility and health may in part explain the results.
authors.affiliation: Section Gerontology and Geriatrics, Department of Internal Medicine, Leiden University Medical Center , Leiden , Netherlands.
authors.forename: Evie
authors.initials: E
authors.lastname: van der Spoel
authors.affiliation: Section Endocrinology, Department of Internal Medicine, Leiden University Medical Center , Leiden , Netherlands.
authors.forename: Ferdinand
authors.initials: F
authors.lastname: Roelfsema
authors.affiliation: Section Gerontology and Geriatrics, Department of Internal Medicine, Leiden University Medical Center , Leiden , Netherlands.
authors.forename: Steffy W
authors.initials: SW
authors.lastname: Jansen
authors.affiliation: Section Gerontology and Geriatrics, Department of Internal Medicine, Leiden University Medical Center , Leiden , Netherlands.
authors.forename: Abimbola A
authors.initials: AA
authors.lastname: Akintola
authors.affiliation: Department of Clinical Chemistry and Laboratory Medicine, Leiden University Medical Center , Leiden , Netherlands.
authors.forename: Bart E
authors.initials: BE
authors.lastname: Ballieux
authors.affiliation: Department of Clinical Chemistry and Laboratory Medicine, Leiden University Medical Center , Leiden , Netherlands.
authors.forename: Christa M
authors.initials: CM
authors.lastname: Cobbaert
authors.affiliation: Section Gerontology and Geriatrics, Department of Internal Medicine, Leiden University Medical Center , Leiden , Netherlands.
authors.forename: Gerard J
authors.initials: GJ
authors.lastname: Blauw
authors.affiliation: Section Molecular Epidemiology, Department of Medical Statistics, Leiden University Medical Center , Leiden , Netherlands.
authors.forename: P Eline
authors.initials: PE
authors.lastname: Slagboom
authors.affiliation: Section Gerontology and Geriatrics, Department of Internal Medicine, Leiden University Medical Center, Leiden, Netherlands; Department of Public Health, Center of Healthy Aging, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Rudi G J
authors.initials: RG
authors.lastname: Westendorp
authors.affiliation: Section Endocrinology, Department of Internal Medicine, Leiden University Medical Center , Leiden , Netherlands.
authors.forename: Hanno
authors.initials: H
authors.lastname: Pijl
authors.affiliation: Section Gerontology and Geriatrics, Department of Internal Medicine, Leiden University Medical Center , Leiden , Netherlands.
authors.forename: Diana
authors.initials: D
authors.lastname: van Heemst
keywords: approximate entropy; familial longevity; hormone secretion; hypothalamic–pituitary–gonadal axis; luteinizing hormone; temporal correlation; testosterone