Blunted Day-Night Changes in Luteinizing Hormone Pulse Frequency in Girls With Obesity: The Potential Role of Hyperandrogenemia

J Clin Endocrinol Metab. 2014 Aug;99(8):2887-96. doi: 10.1210/jc.2013-3258. Epub 2014 Apr 29.

Abstract

Context: Puberty is marked by sleep-associated changes in LH pulse frequency and amplitude. Early pubertal girls with obesity exhibit blunted day-to-night changes in LH secretion; whether this occurs in late pubertal obese girls is unknown.

Objective: The objective of the study was to test two hypotheses: 1) blunted day-to-night changes in LH secretion occur in both early and late pubertal obese girls, and 2) such alterations are specifically associated with hyperandrogenemia.

Design: This was a cross-sectional analysis.

Setting: The study was conducted at a clinical research center.

Patients or other participants: Twenty-seven early pubertal, premenarcheal girls (12 of whom were obese) and 63 late pubertal (postmenarcheal) girls (27 of whom were obese) participated in the study.

Intervention: Blood samples were taken every 10 minutes from 7:00 pm to 7:00 am.

Main outcome measure: Change in LH pulse frequency [LH interpulse interval (IPI)] from daytime hours (7:00 pm-11:00 pm, while awake) to nighttime hours (11:00 pm to 7:00 am, while generally asleep).

Results: Both nonobese and obese postmenarcheal girls demonstrated significant day-to-night decreases in LH pulse frequency (IPI increases of 33% and 16%, respectively), but day-to-night changes were blunted in obese girls (P = .004, obese vs nonobese). Day-to-night LH pulse frequency decreased significantly in postmenarcheal obese subjects with normal T concentrations (26% IPI increase) but not in those with hyperandrogenemia. Similar differences were evident for LH pulse amplitude. Nonobese and obese early pubertal girls exhibited nonsignificant differences in day-night LH pulse frequency (day to night IPI increase of 26% vs decrease of 1%, respectively).

Conclusions: Day-to-night changes in LH pulse secretion are blunted in postmenarcheal obese adolescent girls. This phenomenon may in part reflect hyperandrogenemia.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adolescent
  • Child
  • Circadian Rhythm*
  • Cross-Sectional Studies
  • Female
  • Humans
  • Hyperandrogenism / blood*
  • Luteinizing Hormone / blood
  • Luteinizing Hormone / metabolism*
  • Menarche / blood
  • Obesity / blood*
  • Puberty / blood

Substances

  • Luteinizing Hormone