Pulsatile luteinizing hormone amplitude and progesterone metabolite excretion are reduced in obese women.
BACKGROUND
Female obesity is linked to abnormal menstrual cycles, infertility, reproductive wastage, and deficient LH, FSH, and progesterone secretion.


OBJECTIVE
To elucidate the reproductive defects associated with obesity, we sampled 18 eumenorrheic (nonpolycystic ovary syndrome) women with a mean +/- sem body mass index of 48.6 +/- 1.4 kg/m2 with daily, first morning voided urine collections, seven of whom also had early follicular phase 12-h, every 10-min blood sampling to assess LH pulses. Daily hormones were compared with 11 eumenorrheic, normal-weight controls. A separate control group of 12 eumenorrheic, normal-weight women was used for the LH pulse studies.


METHODS
Assays for LH (serum and urine) and FSH, and estradiol and progesterone metabolites (estrone conjugate and pregnanediol glucuronide; urine) were performed. Daily hormones were meaned and normalized to a 28-d cycle length. LH pulsations were determined using two objective methods. Group means were compared using t tests.


RESULTS
Reduced whole-cycle mean, normalized pregnanediol glucuronide was observed in obese (38.2 +/- 2.1 microg/mg creatine) compared with normal-weight women (181.3 +/- 35.1 microg/mg creatine; P = 0.002), without significant differences in LH, FSH, or estrone conjugate. Early follicular phase LH pulse frequency did not differ from normal-weight women, but both amplitude and mean LH were dramatically reduced in obese women (0.8 +/- 0.1 and 2.0 +/- 0.3 IU/liter) compared with controls (1.6 +/- 0.2 and 3.4 +/- 0.2 IU/liter; P < 0.01).


CONCLUSIONS
A novel defect in the amplitude but not the frequency of LH pulsations appears to underlie the reproductive phenotype of obesity. The deficit in pregnanediol glucuronide appears to exceed the deficit in LH. The patterns of hypothalamic-pituitary-ovarian axis function unique to the obese state differ from other abnormal reproductive states.
Jain
Akas
A
Department of Obstetrics, Gynecology, and Women's Health, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, USA.
Polotsky
Alex J
AJ
Rochester
Dana
D
Berga
Sarah L
SL
Loucks
Tammy
T
Zeitlian
Gohar
G
Gibbs
Karen
K
Polotsky
Hanah N
HN
Feng
Sophia
S
Isaac
Barbara
B
Santoro
Nanette
N
D000328:Adult; D015992:Body Mass Index; D002940:Circadian Rhythm / Q000502:physiology; D005260:Female; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood* / Q000652:urine*; D008597:Menstrual Cycle / Q000378:metabolism; D009765:Obesity / Q000378:metabolism*; D011374:Progesterone / Q000652:urine*; D011673:Pulsatile Flow; D012098:Reproduction / Q000502:physiology
D011374:Progesterone; D007986:Luteinizing Hormone