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

• Published in: The journal of clinical endocrinology and metabolism Vol. 99; no. 8; pp. 2887 - 2896
• Main Authors: Collins, Jessicah S., Beller, Jennifer P., Burt Solorzano, Christine, Patrie, James T., Chang, R. Jeffrey, Marshall, John C., McCartney, Christopher R.
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Oxford University Press 01.08.2014; Copyright by The Endocrine Society; Endocrine Society
• Subjects: Adolescent; Biological and medical sciences; Child; Circadian Rhythm; Cross-Sectional Studies; Endocrine Research; Endocrinopathies; Feeding. Feeding behavior; Female; Fundamental and applied biological sciences. Psychology; Girls; Humans; Hyperandrogenism - blood; Luteinizing hormone; Luteinizing Hormone - blood; Luteinizing Hormone - secretion; Medical sciences; Menarche - blood; Obesity; Obesity - blood; Puberty; Puberty - blood; Secretion; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Vertebrates: endocrinology; Endocrinopathy; Human; Obesity; Night; Nutrition; Nutrition disorder; Metabolic diseases; Gonadotropin; Change; Adenohypophyseal hormone; Blunted effect; Luteinizing hormone; Female; Frequency; Hyperandrogenism; Child; Endocrinology; Nutritional status
• ISSN: 0021-972X; 1945-7197; 1945-7197
• DOI: 10.1210/jc.2013-3258

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.