The utility of the gonadotrophin releasing hormone (GnRH) test in the diagnosis of polycystic ovary syndrome (PCOS)

INTRODUCTION

Polycystic ovary syndrome (PCOS) is characterised by increased frequency of hypothalamic GnRH pulses leading to a relative increase in LH synthesis by the pituitary. As GnRH stimulation can reveal a relative LH excess, we have endeavoured to assess whether GnRH test might be useful in the diagnosis of PCOS.

MATERIAL AND METHODS

The study involved 185 subjects: a PCOS group, n = 151, all with oligo- or amenorrhoea, aged (mean ± SD) 24.8 ± ± 5.4 years, BMI 24.5 ± 6.0 kg/m²; and regularly menstruating controls, n = 34, aged 26.6 ± 5.0 years, BMI 24.6 ± 5.5 kg/m². In 121 subjects with PCOS and in 32 controls, serum LH and FSH were measured before (0 minutes) and 30 and 60 minutes after GnRH stimulation (100 μg i.v.). Insulin resistance was assessed by HOMA and Insulin Resistance Index derived from glucose and insulin concentrations during 75 gram oral glucose tolerance test.

RESULTS

Women with PCOS had higher testosterone (p = 0.0002), androstendione (p = 0.0021), 17OH-progesterone (p < 0.0001) and were more insulin resistant. Raised concentrations of at least one androgen were, however, found only in 58.1% of women with PCOS. Baseline and stimulated LH concentrations were higher in PCOS (9.09 ± 5.56 vs 4.83 ± 1.71 IU/L, 35.48 ± 31.4 vs 16.30 ± 6.68 IU/L, 33.86 ± 31.8 vs 13.45 ± 5.2 IU/L, at 0, 30 and 60 mins post GnRH, respectively, p < 0.0001). There was no difference in baseline or stimulated FSH concentrations between groups. Relative increases of LH or FSH in comparison to respective baseline values were similar in both groups. There was, however, a marked increase in LH/FSH ratio in PCOS in comparison to controls (LH0 min/FSH(₀ min) 1.59 ± 0.95 vs 0.76 ± 0.2, LH(₃₀ min) /FSH(₃₀ min) 4.07 ± 3.0 vs 1.89 ± 0.79, LH(₆₀ min)/FSH(₆₀ min) 3.56 ± 2.58 vs 1.55 ± 0.63, p < 0.0001 at all time points). Further analysis revealed that LH30 min/FSH(₃₀ min) > 2.11 or LH(₆₀ min)/FSH(₆₀ min) > 1.72 had 78.3% and 87.5% sensitivity and 81.7% and 81.3% specificity for the diagnosis of PCOS, respectively.

CONCLUSIONS

Women with PCOS have higher baseline and GnRH-stimulated LH concentrations. GnRH stimulation results in an increase in LH/FSH ratio in women with PCOS. Therefore we postulate that this phenomenon might be potentially useful as an additional tool in the diagnosis of PCOS.

New onset Addison's disease presenting as prolonged hyperemesis in early pregnancy

A 32-year-old Caucasian was admitted at 14 weeks of gestation with hypotension and weight loss. Family members noted that she appeared "tired" prior to pregnancy Past medical history included primary hypothyroidism treated with thyroxine (100 microg/day). She had a healthy daughter aged 2.5 years who had been born small for gestational age. At about 8 weeks of gestation she started to vomit several times a day. She was treated with antiemetics and intravenous fluids. Following discharge she remained nauseated, weak and lightheaded and lost about 8 kg of weight. After readmission she appeared ill and dehydrated, BMI 16.6 kg/m2, BP 90/60 mmHg supine, 70/50 mmHg upright (with faint-like sensation), normal heart sounds, chest clinically clear, abdomen soft and not tender Investigations revealed severe hyponatraemia (sodium 112 mmol/L), normal potassium level 4.3 mmol/L, normal renal function, TSH 1.31 microIU/mL (reference range (RR): 0.27-4.2), freeT4 1.99 ng/dL (RR: 0.93-1.7), freeT3 3.29 pg/mL (RR: 2.57-4.43), anti-TPO antibodies 467 IU/mL (RR: <34)). She was hyperpigmented, hypotensive and hyponatraemic despite rehydration. Cortisol & ACTH, followed by a 250 microg short Synacthen test were requested and revealed peak cortisol response of 17 nmol/L (RR: above 550 nmol/l) as well as high baseline ACTH (969 pg/mL, RR: 0-46 pg/mL). She was started on hydrocortisone and felt tremendously better A diagnosis of Addisons disease was made (in view of hypothyroidism as a part of Autoimmune Polyglandular Syndrome type II). She was discharged on hydrocortisone and fludrocortisone replacement. Further during her pregnancy there was about two-week foetal growth delay. She, however delivered a healthy female infant at 36 weeks of gestation.

CONCLUSIONS

New onset Addison's disease is rare in pregnancy but may present with prolonged vomiting and weight loss. Therefore adrenal failure should be included in the differential diagnosis of hyperemesis gravidarum.

Gelatinase A (MM-2), gelatinase B (MMP-9) and their inhibitors (TIMP 1, TIMP-2) in serum of women with endometriosis: Significant correlation between MMP-2, MMP-9 and their inhibitors without difference in levels of matrix metalloproteinases and tissue inhibitors of metalloproteinases in relation to the severity of endometriosis

Endometriosis is a highly prevalent gynecological condition, where the formation of endometriotic foci is linked with locally increased activity of matrix metalloproteinases (MMPs). In the present study, we tested the hypothesis that raised serum levels of MMPs might reflect the severity of endometriosis. We compared serum levels of MMP-2 and MMP-9, and of their tissue inhibitors TIMP-1 and TIMP-2, in infertile women, matched for age and body mass index, with either mild (stage I, END-I; n = 15) or severe endometriosis (stage IV, END-IV; n = 22). There was no difference in the concentrations of MMP-2, MMP-9, TIMP-1 and TIMP-2 between the analyzed groups. There was, however, a correlation between MMP-9 and TIMP-1 for the combined group (n = 37) (r = 0.48; p = 0.0032) and in women with END-IV (r = 0.51; p = 0.0163), as well as a highly significant correlation between MMP-2 and TIMP-2 for the combined group (r = 0.69; p = 0.0001), END-I (r = 0.51; p = 0.0406) and END-IV groups (r = 0.77; p = 0.0001). There was also a significant correlation between TIMP-1 and TIMP-2 in the combined and END-IV groups (r = 0.39; p = 0.0182 and r = 0.5450; p = 0.0099, respectively). The balance between MMPs and their inhibitors is preserved in the serum of women with endometriosis, but serum concentrations of MMP-2, MMP-9, TIMP-1 and TIMP-2 cannot be considered to represent a valid measure of the severity of endometriosis.