title: Glucose ingestion acutely lowers pulsatile LH and basal testosterone secretion in men.
abstract: Chronic hyperglycemia inhibits the male gonadal axis. The present analyses test the hypothesis that acute glucose ingestion also suppresses LH and testosterone (T) secretion and blunts the LH-T dose-response function. The design comprised a prospectively randomized crossover comparison of LH and T secretion after glucose vs. water ingestion in a Clinical Translational Research Center. The participants were healthy men (n = 57) aged 19-78 yr with body mass index (BMI) of 20-39 kg/m(2). The main outcome measurements were deconvolution and LH-T dose-response analyses of 10-min data. LH-T responses were regressed on glucose, insulin, leptin, adiponectin, age, BMI, and CT-estimated abdominal visceral fat. During the first 120 min after glucose ingestion, for each unit decrease in LH concentrations, T concentrations decreased by 86 (27-144) ng/dl (r = 0.853, P < 0.001). Based upon deconvolution analysis, glucose compared with water ingestion reduced 1) basal (nonpulsatile; P < 0.001) and total (P < 0.001) T secretion without affecting pulsatile T output and 2) pulsatile (P = 0.043) but not basal LH secretion. By multivariate analysis, pulsatile LH secretion positively predicted basal T secretion after glucose ingestion (r = 0.374, P = 0.0042). In addition, the glucose-induced fall in pulsatile LH secretion was exacerbated by higher fasting insulin concentrations (P = 0.054) and attenuated by higher adiponectin levels (P = 0.0037). There were no detectable changes in the analytically estimated LH-T dose-response curves (P > 0.30). In conclusion, glucose ingestion suppresses pulsatile LH and basal T secretion acutely in healthy men. Suppression is influenced by age, glucose, adiponectin, and insulin concentrations.
authors.affiliation: Endocrine Research Unit, Mayo School of Graduate Medical Education, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: Ali
authors.initials: A
authors.lastname: Iranmanesh
authors.forename: Donna
authors.initials: D
authors.lastname: Lawson
authors.forename: Johannes D
authors.initials: JD
authors.lastname: Veldhuis
mesh_terms: D050153:Abdominal Fat / Q000502:physiology; D052242:Adiponectin / Q000097:blood; D000328:Adult; D000368:Aged; D000375:Aging / Q000378:metabolism; D000704:Analysis of Variance; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D018592:Cross-Over Studies; D003864:Depression, Chemical; D004305:Dose-Response Relationship, Drug; D005947:Glucose / Q000494:pharmacology*; D005951:Glucose Tolerance Test; D006801:Humans; D007333:Insulin Resistance; D016014:Linear Models; D007986:Luteinizing Hormone / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013739:Testosterone / Q000378:metabolism*; D055815:Young Adult
chemical_list: D052242:Adiponectin; D001786:Blood Glucose; D013739:Testosterone; D007986:Luteinizing Hormone; D005947:Glucose