Antim ullerian hormone and polycystic ovary syndrome

Transcription

1 Antim ullerian hormone and polycystic ovary syndrome Yi-Hui Lin, M.D., a Wan-Chun Chiu, Ph.D., c Chien-Hua Wu, Ph.D., b,e Chii-Ruey Tzeng, M.D., d Chun-Sen Hsu, M.D., a and Ming-I Hsu, M.D. a a Department of Obstetrics and Gynecology, and b Center of Excellence for Clinical Trials and Research, Wan Fang Hospital, c School of Nutrition and Health Sciences, College of Public Health and Nutrition, and d Department of Obstetrics and Gynecology, Taipei Medical University Hospital, Taipei Medical University, Taipei; and e Department of Applied Mathematics, Chung-Yuan Christian University, Chung-Li, Taiwan Objective: To assess the relationship between antim ullerian hormone (AMH) and parameters related to polycystic ovary syndrome (PCOS). Design: Prospective study. Setting: Academic tertiary care center. Patient(s): A total of 290 women. Intervention(s): None. Main Outcome Measure(s): Parameters related to insulin resistance and metabolic syndrome. Result(s): Women with polycystic ovary morphology had significantly higher AMH levels than women in the control group. The prevalence of PCOS increased from 21% in the low-amh (<4 ng/ml) group to 37% in the moderate-amh (4 11 ng/ml) group and 80% in the high-amh (>11 ng/ml) group. However, significant differences in insulin resistance parameters were not observed among groups. The results of the correlation analysis revealed that AMH levels were positively correlated with LH, total T, A, and total cholesterol content; however, AMH levels were negatively correlated with age, body mass index, and the number of menstrual cycles per year. AMH levels were not correlated with insulin resistance parameters. Conclusion(s): Elevated serum AMH levels increase the risk of PCOS but do not affect the risk of insulin resistance or metabolic syndrome. (Fertil Steril Ò 2011;96: Ó2011 by American Society for Reproductive Medicine.) Key Words: AMH, PCOS, insulin resistance, metabolic syndrome Antim ullerian hormone (AMH) levels indicate the quantity of the ovarian follicle pool and may be a useful marker of ovarian reserves (1). The measurement of AMH levels can be useful in assisted reproductive technologies for predicting poor response, cycle cancellation, hyperresponse, and ovarian hyperstimulation syndrome (2). In addition, serum AMH levels are an important marker of polycystic ovary syndrome (PCOS). Women with PCOS have 2- to 3-fold higher levels of AMH than healthy women (3). Serum AMH levels are correlated with three diagnostic hallmarks of PCOS, including hyperandrogenism (HA), oligoanovulation (ANOV), and polycystic ovary morphology (PCOM) (4, 5). The differences in circulating AMH levels between the main phenotypic groups of women with PCOS appear to reflect the severity of the syndrome (6). Do high AMH levels increase the risk of PCOS, insulin resistance, and/or metabolic abnormalities? Are the serum levels of AMH associated with various PCOS phenotypes? Are the clinical and/or biochemical presentations between high and low AMH levels in women with and without PCOS different? Received November 28, 2010; revised March 28, 2011; accepted April 5, 2011; published online May 5, Y.-H.L. has nothing to disclose. W.-C.C. has nothing to disclose. C.-H.W. has nothing to disclose. C.-R.T. has nothing to disclose. C.-S.H. has nothing to disclose. M.-I.H has nothing to disclose. The first two authors contributed equally to this work. Supported by grants from the National Science Council (NSC B MY3) and Taipei Medical University and Wan Fang Hospital (98TMU-WFH and DOH100-TD-B ). Reprint requests: Ming-I Hsu, M.D., Department of Obstetrics and Gynecology, Wan Fang Hospital, Taipei Medical University, No.111, Sec. 3, Xinglong Rd., Taipei 11696, Taiwan ( hsumingi@yahoo.com.tw). The prospective study described in the present report was conducted to answer these questions. MATERIALS AND METHODS The study was approved by the Institutional Review Board of the Wan Fang Medical Center at Taipei Medical University, Taipei, Taiwan, and was conducted at the Reproductive Endocrinology Clinic from June 1, 2009, to September 31, The study population consisted of patients and healthy volunteers. Patients who complained of infertility, menstrual irregularity, and hyperandrogenism were recruited from the gynecologic outpatient clinic. Each of the studied subjects gave informed consent. The following subjects were excluded from the study and control populations: 1) women who had been diagnosed with other etiologies that should be excluded when diagnosing PCOS (7); 2) women who experienced menarche <3 years before the beginning of the study; 3) women who received hormones or drugs for major medical diseases; 4) women who presented ovarian cysts or ovarian tumors; and 5) women who were >45 years old. In total, 290 women were recruited. The subjects medical histories were obtained, and the number of menstrual cycles during the previous year was recorded. The waist-to-hip ratio (WHR) was defined as the waist girth/hip girth, and the body mass index (BMI) was defined as the body weight in kilograms divided by the body height in meters squared (kg/m 2 ). Obesity was defined as a BMI R25 kg/m 2. The following components were measured and calculated: 1) total testosterone (T), androstenedione (A), DHEAS, and 17a-OH-progesterone levels and the free androgen index (FAI); 2) fasting insulin, fasting glucose, 2-hour oral glucose tolerance test (OGTT) glucose level, the homeostasis model assessment of insulin resistance index (HOMA-IR), and the presence of diabetes; 3) serum FSH, LH, and PRL; 4) total cholesterol, triglycerides (TG), high-density lipoprotein (HDL), and low-density lipoprotein (LDL); and 5) glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), and high-sensitivity C-reactive protein (hscrp) levels. AMH levels were measured with an ELISA kit (Diagnostic Systems Laboratories). The FAI was calculated by using the formula FAI ¼ T (nmol/l) 230 Fertility and Sterility â Vol. 96, No. 1, July /$36.00 Copyright ª2011 American Society for Reproductive Medicine, Published by Elsevier Inc. doi: /j.fertnstert

2 FIGURE 1 The mean serum antim ullerian hormone (AMH) levels of various polycystic ovary syndrome related phenotypes. Error bars represent 95% confidence intervals. ANOV ¼ oligoanovulation; HA ¼ hyperandrogenism; PCOM ¼ polycystic ovary morphology. 100/SHBG (nmol). Hyperandrogenism was defined as a total serum T level R2.98 mmol/l. PCOS was diagnosed according to the 2003 Rotterdam criteria, which require a minimum of two of the three following traits: ANOV, HA, and PCOM. The definitions of ANOV, HA, and PCOM have been previously described (7). A single ultrasound machine was used for the evaluation of PCOM (Medison SA-8000 Live). Insulin Sensitivity, Metabolic Syndrome, and Glucose Intolerance The insulin sensitivity index was evaluated by HOMA-IR, and the following formula was applied: HOMA-IR ¼ (fasting insulin [mu/ml] fasting glucose [mg/dl])/405. World Health Organization 2006 diagnostic criteria for diabetes were used (fasting plasma glucose [FPG] R126 mg/dl or 2-hour plasma glucose R200 mg/dl). Impaired glucose tolerance (IGT) was defined as 2-hour glucose levels of mg/dl in the 75-g oral glucose tolerance test. In women with IGT, the FPG level should be <126 mg/dl (8). Metabolic syndrome was defined (2005 National Cholesterol Education Program Adult Treatment Panel III [ATP III]) as the presence of at least three of the following criteria: abdominal obesity (waist circumference >80 cm in women), serum TG R150 mg/dl, serum HDL <50, blood pressure (BP) R130/85 mm Hg, and FPG R100 mg/dl. Statistical Analysis Statistical analysis was performed using SPSS 13.0 for Windows. Figure 1 presents the mean, error bars, and 95% confidence intervals of the AMH levels of the eight subgroups. In Table 1, the data are presented as mean SD. To compare the means of more than two groups, one-way analysis of variance and post hoc Dunnett tests were performed, and equal variances were not assumed. Receiver operating characteristic (ROC) curves of the AMH levels were constructed to examine the diagnostic test performance for PCOS. To determine the optimal thresholds for the AMH levels, the point on the ROC curve with the maximum Youden index (sensitivity [1 specificity]) was calculated (9). We evaluated the correlation between the AMH level and various parameters by determining the two-tailed Pearson correlation coefficient. Differences among groups were considered to be significant if the P value was <.05. RESULTS In total, 290 women were recruited, including 126 with PCOS and 164 women without PCOS. The subjects were categorized into eight groups based on their diagnostic characteristics. The 126 subjects with PCOS were classified into four subgroups: ANOV þ HA, HA þ PCOM, ANOV þ PCOM, and HA þ ANOV þ PCOM. The 164 subjects without PCOS also were categorized into four subgroups: HA only, ANOV only, PCOM only, and normal control. Figure 1 presents the mean serum AMH level of the eight subgroups of PCOS-related phenotypes. The serum AMH levels of the four PCOM subgroups were significantly greater than that of the control and ANOV-only subgroup. Women in the HA þ ANOV þ PCOM subgroup had the highest levels of serum AMH, whereas women in the normal control subgroup had the lowest levels. The overall distribution of AMH in the entire population (n ¼ 290) was analyzed, and the subjects were divided into three groups: high AMH (>11 ng/ml), moderate AMH (4 11 ng/ml), and low AMH (<4 ng/ml). The clinical and biochemical characteristics of subjects with low, moderate, and high AMH levels are presented in Table 1. As the AMH level increased, the prevalence of PCOS increased significantly from 21% in the low-amh group to 37% in the moderate-amh group and 80% in the high-amh group. Compared with the moderate AMH group, the rates of HA, ANOV, and PCOM were also greater in the high-amh group. Body weight, waist circumference, and BMI were significantly higher in the low-amh group compared with the moderate- and Fertility and Sterility â 231

3 232 Lin et al. Antim ullerian hormone and PCOS Vol. 96, No. 1, July 2011 TABLE 1 Biochemical and clinical characteristics of women in their reproductive age with low, moderate, and high levels of AMH. Total AMH <4 (L) AMH 4 11 (M) AMH >11 (H) P value L vs. M L vs. H M vs. H n Age (y) *.010*.727 AMH (ng/ml) <.001*** <.001*** <.001*** Menarche (y) No. of cycles per year <.001*** <.001*** Oligoanovulation 44% 31% 36% 73%.762 <.001*** <.001*** Polycystic ovary morphology 43% 11% 43% 79% <.001*** <.001*** <.001*** Hyperandrogenemia 39% 25% 36% 57%.218 <.001***.014* Polycystic ovary syndrome 43% 21% 37% 80%.029* <.001*** <.001*** Obesity 45% 54% 45% 34% Anthropometric components Weight (kg) *.013*.839 Height (cm) Body mass index (kg/m 2 ) *.019*.790 Waist (cm) *.023*.890 Hip (cm) *.003**.489 Waist-to-hip ratio No. of follicles <.001*** <.001*** <.001*** Androgens Total T (nmol/l) <.001*** <.001*** Androstenedione (ng/dl) * <.001*** <.001*** Free androgen index *.111 DHEAS (ng/dl) OH-P (ng/dl) Insulin sensitivity and glucose tolerance Fasting insulin (uiu/ml) Fasting glucose (mg/dl) hour glucose (mg/dl) HOMA-IR Impaired glucose tolerance 21% 29% 20% 16% Diabetes 5% 7% 4% 6% Hormonal components LH (miu/ml) **.062 FSH (miu/ml) TSH (miu/ml) PRL (ng/ml) SHBG (nmol/l) Inflammatory components hscrp (mg/dl)

4 Fertility and Sterility â 233 TABLE 1 Continued. Total AMH <4 (L) AMH 4 11 (M) AMH >11 (H) P value L vs. M L vs. H M vs. H Liver function GOT (IU/L) GPT (IU/L) Lipid profiles and blood pressure Cholesterol (mg/dl) *.217 Triglycerides (mg/dl) HDL (mg/dl) LDL (mg/dl) Systolic pressure (mm Hg) Diastolic pressure (mm Hg) Metabolic syndrome Metabolic syndrome 26% 34% 25% 20% Hypertension 30% 36% 29% 24% HDL <50 mg/dl 50% 64% 47% 44%.045* Triglycerides >150 mg/dl 11% 15% 10% 9% Waist >80 cm 52% 65% 50% 45% Note: Unless indicated as percentage, values are mean SD. GOT ¼ glutamic oxaloacetic transaminase; GPT ¼ glutamic pyruvic transaminase; HDL ¼ high-density lipoprotein; HOMA-IR ¼ homeostasis model assessment insulin resistance index; hscrp ¼ high-sensitivity C-reactive protein; LDL ¼ low-density lipoprotein. * P<.05. ** P<.01. *** P<.001.

5 FIGURE 2 Receiver-operating characteristic (ROC) curves of antim ullerian hormone (AMH) levels for the evaluation of polycystic ovary syndrome (PCOS). high-amh groups. The high-amh group presented significantly higher total T and A levels than the low- and moderate-amh groups. Interestingly, significant differences in glucose tolerance, insulin resistance, liver enzyme concentration, lipid profile, or risk of metabolic syndrome were not observed among the low-, moderate-, and high-amh groups. However, significant differences in the total cholesterol level and the prevalence of HDL <50 mg/dl were observed among the groups. Using the ROC curves, the diagnostic potency of the AMH assay was tested. As shown in Figure 2, the AUC of AMH for the prediction of PCOS reached (95% confidence interval [CI] ). The largest Youden index and optimal specificity (76%) and sensitivity (70%) for the prediction of PCOS were obtained when the threshold AMH concentration was set to 7.3 ng/ml. The correlation analyses revealed that AMH levels were positively correlated with LH (g ¼ 0.229; P<.001), total T (g ¼ 0.389; P<.001), A (g ¼ 0.396; P<.001), total cholesterol (g ¼ 0.174; P¼.003), HDL (g ¼ 0.119; P¼.044), LDL (g ¼ 0.136; P¼.020), and average ovarian volume (g ¼ 0.459; P<.001); however, the AMH concentration was negatively correlated with age (g ¼ 0.205; P<.001), BMI (g ¼ 0.166; P¼.004), number of menstrual cycles per year (g ¼ 0.330; P<.001), and fasting glucose levels (g ¼ 0.130; P¼.027). AMH levels were not correlated with insulin resistance parameters (HOMA-IR), liver function (GOT and GPT), or hs-crp. Logistic regression analysis was applied to PCOS-related parameters (AMH, LH, LH:FSH ratio, WHR, HOMA-IR, SHBG, HDL, GPT, and hscrp), and the results revealed that AMH and SHBG were significantly associated with PCOS. Furthermore, a partial correlation analysis adjusted by age and BMI was conducted, and the results revealed that the relationship between AMH levels and insulin resistance parameters was independent. DISCUSSION To quantify the serum AMH levels and various factors related to PCOS, the subjects were categorized into eight subgroups according to the three hallmarks of PCOS. The results showed that the serum AMH levels of the four PCOM subgroups were significantly higher than that of the normal control subgroup. Similarly to earlier reports, the results of the correlation analyses demonstrated that AMH was positively correlated with the total T and A levels. Furthermore, increased AMH levels were correlated with a reduction in the number of menstrual cycles per year (4, 5). These results are consistent with those obtained by Piouka et al., who demonstrated that high AMH levels reflect the severity of PCOS (6). Because AMH levels are positively correlated with the three components of PCOS, the concentration of AMH should be considered to be a predictor of PCOS. In a study conducted on a cohort of 73 PCOS patients and 96 control subjects, Pigny et al. (10) conducted an ROC analysis and found that the area under the curve of an AMH assay for the prediction of PCOS was equal to (95% CI ). When the threshold was set to 60 pmol/l (8.4 ng/ml), a compromise between specificity (92%) and sensitivity (67%) was obtained. In the present study, the area under the ROC curve for AMH reached (95% CI ) for the prediction of PCOS. The primary difference between the present investigation and the study conducted by Pigny et al. is that 68 PCOS-risk cases were included in the present study. These patients were diagnosed with one of three PCOS components (HA, PCOM, or ANOV) and were included in the non-pcos group. PCOS is not a rare disease; therefore, to prevent selection bias, women with HA, ANOV, or PCOM that have been diagnosed as non-pcos should not be excluded (11). Our analysis demonstrated that the largest Youden index and the optimal combined specificity (76%) and sensitivity (70%) for the prediction of PCOS were obtained when the AMH threshold was set to 7.3 ng/ml. However, our results, and those of Pigny et al., suggest that the evaluation of serum AMH levels is an important breakthrough in the diagnosis and understanding of PCOS (3). In the present study, the subjects were classified into low-, moderate-, and high-amh subgroups, and the results suggested that the prevalence of PCOS increased with an increase in AMH concentration (from 21% in the low-amh group to 37% in the moderate-amh group and 80% in the high-amh group). Alternatively, glucose intolerance, insulin resistance, lipid profile, and risk of metabolic syndrome (except for total cholesterol level and HDL content) were not significantly different among the low-, moderate-, and high-amh subgroups. In fact, the relationship between insulin resistance and AMH has been a source of controversy (12, 13). Chen et al. (12) discovered that AMH was negatively associated with BMI and HOMA-IR. In contrast, Park et al. (13) observed an independent relationship between HOMA-IR and AMH in women without PCOS. The results of the present study suggest that an increase in the serum AMH level may increase the risk of PCOS in women of reproductive age. However, the AMH level did not affect the risk of insulin resistance or metabolic syndrome. In the present study and in earlier reports, serum AMH levels were negatively correlated with age and BMI (2, 13). Although the low AMH group had the highest average age and BMI, an independent relationship between AMH and insulin resistance and/or metabolic syndrome was observed when a partial correlation analysis adjusted by age and BMI was conducted. The subjects evaluated in the present study were recruited from the outpatient clinic of a tertiary care center and do not reflect the 234 Lin et al. Antim ullerian hormone and PCOS Vol. 96, No. 1, July 2011

6 true distribution of the general population. As described in the inclusion criteria, women diagnosed with conditions that should be excluded in the diagnosis of PCOS, such as hyperprolactinemia, premature ovarian failure, or even premenopause, were not included in the present study. Therefore, the results should be applied to the general population with caution. CONCLUSION In women with PCOS, AMH levels may reflect specific ovarian anomalies but are not indicative of metabolic anomalies. Elevated serum AMH levels are associated with an increased risk of PCOS; however, an increase in AMH levels was not correlated with an increased risk of insulin resistance and metabolic syndrome. REFERENCES 1. Kwee J, Schats R, McDonnell J, Themmen A, de Jong F, Lambalk C. Evaluation of anti-m ullerian hormone as a test for the prediction of ovarian reserve. Fertil Steril 2008;90: la Marca A, Sighinolfi G, Radi D, Argento C, Baraldi E, Artenisio AC, et al. Anti-mullerian hormone (AMH) as a predictive marker in assisted reproductive technology (ART). Hum Reprod Update 2010;16: Pigny P, Merlen E, Robert Y, Cortet-Rudelli C, Decanter C, Jonard S, et al. Elevated serum level of antimullerian hormone in patients with polycystic ovary syndrome: relationship to the ovarian follicle excess and to the follicular arrest. J Clin Endocrinol Metab 2003;88: Carlsen SM, Vanky E, Fleming R. Anti-m ullerian hormone concentrations in androgen-suppressed women with polycystic ovary syndrome. Hum Reprod 2009;24: Pellatt L, Rice S, Mason H. Anti-mullerian hormone and polycystic ovary syndrome: a mountain too high? Reproduction 2010;139: Piouka A, Farmakiotis D, Katsikis I, Macut D, Gerou S, Panidis D. Anti-mullerian hormone levels reflect severity of PCOS but are negatively influenced by obesity: relationship with increased luteinizing hormone levels. Am J Physiol Endocrinol Metab 2009;296:E Hsu MI, Liou TH, Liang SJ, Su HW, Wu CH, Hsu CS. Inappropriate gonadotropin secretion in polycystic ovary syndrome. Fertil Steril 2009;91: World Health Organization. Definition and diagnosis of diabetes mellitus and intermediate hyperglycemia; report ofa WHO/IDF consultation. WHO Document Production. Geneva: World Health Organization; Pepe M. The statistical evaluation of medical tests for classification and prediction. New York: Oxford University Press; Pigny P, Jonard S, Robert Y, Dewailly D. Serum antimullerian hormone as a surrogate for antral follicle count for definition of the polycystic ovary syndrome. J Clin Endocrinol Metab 2006;91: Bloom MS, Schisterman EF, Hediger ML. Selecting controls is not selecting normals : design and analysis issues for studying the etiology of polycystic ovary syndrome. Fertil Steril 2006;86: Chen MJ, Yang WS, Chen CL, Wu MY, Yang YS, Ho HN. The relationship between anti-mullerian hormone, androgen and insulin resistance on the number of antral follicles in women with polycystic ovary syndrome. Hum Reprod 2008;23: Park HT, Cho GJ, Ahn KH, Shin JH, Kim YT, Hur JY, et al. Association of insulin resistance with antimullerian hormone levels in women without polycystic ovary syndrome (PCOS). Clin Endocrinol (Oxf) 2010;72: Fertility and Sterility â 235