Endocrine Research

ISSN: 0743-5800 (Print) 1532-4206 (Online) Journal homepage: http://www.tandfonline.com/loi/ierc20

A possible link between luteinizing hormone and macrophage migration inhibitory factor levels in polycystic ovary syndrome Mehmet Calan, Tuncay Kume, Ozgur Yilmaz, Tugba Arkan, Gokcen Unal Kocabas, Ozge Dokuzlar, Kemal Aygün, Mehmet Asi Oktan, Nilay Danıs & Muzaffer Temur To cite this article: Mehmet Calan, Tuncay Kume, Ozgur Yilmaz, Tugba Arkan, Gokcen Unal Kocabas, Ozge Dokuzlar, Kemal Aygün, Mehmet Asi Oktan, Nilay Danıs & Muzaffer Temur (2016): A possible link between luteinizing hormone and macrophage migration inhibitory factor levels in polycystic ovary syndrome, Endocrine Research, DOI: 10.3109/07435800.2015.1135442 To link to this article: http://dx.doi.org/10.3109/07435800.2015.1135442

Published online: 25 Feb 2016.

Submit your article to this journal

Article views: 14

View related articles

View Crossmark data

Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=ierc20 Download by: [Orta Dogu Teknik Universitesi]

Date: 06 March 2016, At: 04:20

ENDOCRINE RESEARCH http://dx.doi.org/10.3109/07435800.2015.1135442

A possible link between luteinizing hormone and macrophage migration inhibitory factor levels in polycystic ovary syndrome Mehmet Calana, Tuncay Kumeb, Ozgur Yilmazc, Tugba Arkana, Gokcen Unal Kocabasd, Ozge Dokuzlare, Kemal Aygüne, Mehmet Asi Oktane, Nilay Danıse, and Muzaffer Temurc a

Division of Endocrinology and Metabolism, Department of Internal Medicine, Dokuz Eylul University Medical School, Izmir, Turkey; Department of Medical Biochemistry, Dokuz Eylul University Medical School, Izmir, Turkey; cDepartment of Obstetrics and Gynecology, Manisa Merkezefendi Hospital, Manisa, Turkey; dDivision of Endocrinology and Metabolism, Department of Internal Medicine, Izmir Bozyaka Training and Research Hospital, Izmir, Turkey; eDepartment of Internal Medicine, Dokuz Eylul University Medical School, Izmir, Turkey

Downloaded by [Orta Dogu Teknik Universitesi] at 04:20 06 March 2016

b

ABSTRACT

ARTICLE HISTORY

Purpose: Macrophage migration inhibitory factor (MIF) is a multifunctional cytokine that plays a role in metabolic and inflammatory processes. Increasing evidence suggests that there is a link between MIF and ovulation. We aimed to evaluate plasma MIF levels in women with polycystic ovary syndrome (PCOS) and to determine whether MIF levels differ between the follicular phase and mid-cycle of the menstrual cycle in eumenorrheic women. Methods: Ninety women with PCOS and 80 age- and BMI-matched healthy eumenorrheic women were consecutively recruited into this prospective observational study. For all subjects, plasma MIF levels in the early follicular phase were measured by ELISA; for the 40 healthy controls, MIF levels were also measured during mid-cycle of the same menstrual cycle. Results: Plasma MIF levels were significantly higher in women with PCOS than in eumenorrheic women (14.16 ± 1.59 vs. 10.39 ± 0.70 ng/ml; p < 0.001). MIF levels were significantly higher at mid-cycle than in the follicular phase in eumenorrheic women (11.15 ± 0.61 vs. 10.56 ± 0.82 ng/ml; p < 0.001). MIF was positively correlated with BMI, high sensitivity C-reactive protein (hs-CRP), and homeostasis model assessment of insulin resistance (HOMA-IR) in both groups. MIF was positively correlated with luteinizing hormone (LH) and free-testosterone only in the PCOS group. Binary logistic regression analyses revealed that the odds ratio (OR) for PCOS independently increases linearly with elevated MIF (OR = 1.385, 95% CI = 1.087–1.764, p = 0.017). Conclusion: MIF may play a crucial role in the reproductive system in women, including the development of PCOS and normal ovulation.

Received 5 February 2015 Revised 25 October 2015 Accepted 2 December 2015 published online 9 February 2016

Introduction Polycystic ovary syndrome (PCOS) is a complex disorder including both hormonal and metabolic abnormalities and is the most common endocrine disorder in women of reproductive age, with a prevalence of up to 10%. The principal features of PCOS are ovulatory dysfunction, biochemical (elevated CONTACT Mehmet Calan, MD [email protected] University Medical School, Inciralti, Izmir, 35340 Turkey. © 2016 Taylor & Francis

KEYWORDS

Insulin resistance; luteinizing hormone; macrophage migration inhibitory factor; ovulation; polycystic ovary syndrome ABBREVIATIONS

BMI: body mass index; CI: confidence interval; CV: coefficient of variability; E2: estradiol; FBG: fasting blood glucose; FG: ferriman-gallwey; FSH: follicle-stimulating hormone; HDL-C: high density lipoprotein cholesterol; HOMA-IR: homeostasis model assessment of insulin resistance; hs-CRP: high sensitivity C-reactive protein; LDL-C: low density lipoprotein cholesterol; LH: luteinizing hormone; MIF: macrophage migration inhibitory factor; OR: odds ratio; PCOS: polycystic ovary syndrome; VIF: variance inflation factor; WHR: waist to hip ratio

androgens) and clinical (hirsutism and/or acne) hyperandrogenism, and/or polycystic ovaries. Environmental and genetic factors also have a role in the development of PCOS, but its etiology remains unknown (1,2). PCOS is associated with low-grade chronic inflammation, insulin resistance, glucose intolerance, metabolic syndrome, hyperlipidemia, hypertension, obesity, and an increased risk of

Division of Endocrinology and Metabolism, Department of Internal Medicine, Dokuz Eylul

Downloaded by [Orta Dogu Teknik Universitesi] at 04:20 06 March 2016

2

M. CALAN ET AL.

developing type 2 diabetes and cardiovascular diseases. Furthermore, obesity exacerbates both the metabolic and reproductive abnormalities in women with PCOS (2–5). Increased fat mass is associated with an increased number of macrophages, which secrete cytokines such as tumor necrosis factor alpha (TNF-α), interleukins, and macrophage migration inhibitory factor (MIF) (6–8). MIF was the first described pro-inflammatory cytokine and plays an important role in acute and chronic inflammatory states such as sepsis, glomerulonephritis, rheumatoid arthritis, and systemic lupus erythematosus (9–12). Elevated MIF levels have also been demonstrated in some low-grade chronic inflammatory-based diseases including diabetes mellitus, gestational diabetes, and atherosclerosis (7,13–17). Furthermore, MIF has been found within the insulin-containing granules of the islets of Langerhans and shown to be secreted during both phases of insulin secretion (15). MIF may contribute to the regulation of insulin secretion. Moreover, it was demonstrated that MIF inhibited insulin signal transduction via tyrosine phosphorylation of insulin receptor substrate-1 in adipose tissue (18). Increasing evidence suggests that MIF also plays a crucial role in the regulation of follicular growth and ovulation, probably via TNF-α, prostaglandins, and nitric oxide (NO) (19–24). Nevertheless, contrary results have been reported about the MIF levels in women with PCOS. Glintbory et al. reported that MIF levels were decreased significantly in women with PCOS compared to a healthy control group (25). González et al. and Mejia-Montilla et al. reported that circulating MIF levels were elevated in women with PCOS (26,27). In the present study, we therefore aimed to clarify the MIF levels in women with PCOS and whether MIF levels differ between the follicular phase and mid-cycle of the same ovulatory cycle in eumenorrheic women.

Materials and methods Subjects and study design

The research was designed as a prospective observational study and was approved by the local ethics committee. The research was conducted between January 2013 and January 2014 in the Department of Obstetrics and Gynecology of Merkezefendi State Hospital in Manisa, Turkey. Written informed

consent was obtained from all the volunteers who complied with the research protocol. The study adhered strictly to the Declaration of Helsinki Principles as revised in 2008. We consecutively recruited subjects in an attempt to match BMI and age for each group. We recruited 90 subjects with PCOS and 80 subjects with normal menstrual cycles who presented to our clinic and met the inclusion and exclusion criteria. Forty healthy regularly menstruating women were randomly selected from the control group and they were followed mid-cycle (13–15 days) and mid-luteal phase (21–23 days) of the same menstrual cycle. We considered the cycle as ovulatory if a mid-cycle LH peak occurred and the mid-luteal serum progesterone exceeded a concentration of 10 ng/ml (28). All progesterone levels among these women were higher than 10 ng/ml. Clinical and anthropometric variables were evaluated by a single investigator in all subjects. All the recruited women were Caucasian. PCOS group

The diagnosis of PCOS in the study was made based on the 2003 Rotterdam consensus criteria (29). Accordingly, at least two of the following criteria were required for PCOS diagnosis: (1) Oligo- or anovulatory menstrual dysfunction (manifested as infrequent bleeding at intervals greater than 35 days); (2) clinical hyperandrogenism, defined as a presence of hirsutism (≥8 Ferriman–Gallwey score) (30), and/or biochemical hyperandrogenism, defined as an increase in the serum concentrations of free-testosterone (normal values: 2.9–31.8 ng/dL); (3) typical ultrasonographic finding of polycystic ovaries (with one ovary being sufficient for diagnosis), defined as the presence of 12 or more follicles measuring 2–9 mm in diameter or an ovarian volume of greater than 10 ml (without a cyst or dominant follicle in either ovary), after exclusion of other causes of hyperandrogenism. Control group

Control subjects were recruited from healthy women who visited the gynecology clinic for routine annual examination or who were seen for other reasons such as pelvic pain, premenstrual

ENDOCRINE RESEARCH

syndrome, or dysmenorrhea. Volunteers had regular menstrual cycles (28–32 days) and no concomitant health problems. They had no signs of hirsutism or hyperandrogenism.

Downloaded by [Orta Dogu Teknik Universitesi] at 04:20 06 March 2016

Exclusion criteria

The exclusion criteria included other causes of irregular menstrual cycles and/or androgen excess such as hyperprolactinemia, Cushing’s syndrome, congenital adrenal hyperplasia or other diseases of the adrenal gland, thyroid disorders, galactorrhea, breastfeeding, and pregnancy. Women with impaired glucose tolerance, type 1/type 2 diabetes, and those using anti-hyperglycemic agents or insulin were excluded from the study. Also, women with hypertension, hyperlipidemia, active and chronic liver or renal failure, congestive heart failure or any other known major disease, a history of coronary artery disease, or gestational diabetes mellitus were excluded from the study. Furthermore, women with a history of acute infection within the previous 14 days, presence of any chronic inflammatory or autoimmune disease, or known malignancy were excluded from the study. None of the women were using or had previously used antiobesity medications or medications known to affect glucose tolerance, lipid metabolism, or blood pressure. None of the subjects used tobacco or alcohol.

Anthropometric evaluation

Of the individuals included in the study, a detailed history was taken. Following general physical examination of the subjects, anthropometric measurements were performed (age, weight, height, waist and hip circumference). Height (centimeter) and weight (kilogram) were measured with the subject barefoot in light daily clothes. Body mass index (BMI) was calculated using the formula weight (kg)/square meter of height (m2). Waist circumference (cm) was measured midway between the lower rib margin and the iliac crest at the end of a gentle expiration. Hip circumference was measured at the maximum circumference over the buttocks. Body fat percentage was measured by bioelectrical impedance analysis method (Tanita, TBF-401, Japan).

3

Biochemical evaluation

Venous blood samples were collected from the antecubital veins of the participants during the early follicular phase of menstrual bleeding (days 3–5), after the onset of early spontaneous or progesterone-induced menses, following at least 12-hour fasting. Fasting blood glucose (FBG), serum insulin, high sensitivity CRP (hs-CRP), total cholesterol, triglycerides, highdensity lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), free-testosterone, follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), and plasma MIF levels were measured. Furthermore, 40 women in the control group were followed mid-cycle and in the luteal phase of the same menstrual cycle. Following at least 12-hour fasting, blood was drawn on days 13–15 (ovulation) of the menstrual cycle to measure MIF and LH levels. Also, blood was drawn on days 21–23 (mid-luteal phase) of the menstrual cycle to measure progesterone levels. To measure plasma MIF levels, blood samples were collected in ethylenediaminetetraacetic acid (EDTA) tubes. Serum glucose, hs-CRP, total cholesterol and HDL-C, and triglyceride levels were determined using an autoanalyzer (Abbott Architect C 16000, IL, USA) with its dedicated kits (Abbott Diagnostics, Wiesbaden, Germany). LDL-C was calculated using the Friedewald equation [LDL-C = total cholesterol – (HDL-C + Triglyceride/5)]. Serum insulin levels were measured by an autoanalyzer (Abbott Architect I2000, IL, USA) using chemiluminescent microparticle immunoassay (CMIA) with its dedicated kits (Abbott Diagnostics, Wiesbaden, Germany). Serum FSH, LH, and E2 levels were measured by the CMIA technique (Beckman Coulter Inc., Brea, USA). Serum free-testosterone levels were measured using the radioimmunoassay (RIA) method (Beckman Coulter DSL 4900 Gamma Counter, USA). Serum progesterone levels were measured by the CMIA method (Abbott Architect i4000 autoanalyzer). Plasma MIF levels were analyzed with an ELISA technique (Boster Biological Tech., Wuhan, China) according to the manufacturer’s protocol. The intra-assay coefficient of variation (CV) was 0.05). Continuous variables were presented as mean ± standard deviation (SD). Demographic and laboratory characteristics of the studied women with and without PCOS were compared using independent samples t-test (two-tailed). Relationships between MIF and other demographic and laboratory characteristics were evaluated using Pearson’s correlation analysis. Differences in follicular phase and mid-cycle MIF levels in eumenorrheic women were analyzed by a paired t-test. To adjust the covariates and to identify independent relationships between MIF levels and age, BMI, visceral fat, hs-CRP, free-testosterone, HOMA-IR, LH, and LDL-C, triglyceride multiple linear regression analyses were performed (method “enter”). All independent variables in the multiple linear regression were tested for multicollinearity. If the variance inflation factor (VIF) exceeded 4, the variable was considered to be collinear. Therefore, waist circumference was not included in the models. To examine the association of MIF levels with the development of PCOS, we calculated the odds ratio (OR) with multivariate logistic regression analysis (method “enter”). All model compatibility was analyzed using the Hosmer and Lemeshow test and the analysis revealed that the models were compatible (p > 0.05). All reported confidence interval (CI) values were calculated at the 95% level. A two-sided p-value < 0.05 was considered statistically significant.

Table 1. Comparison of the demographic and laboratory characteristics of the study population. Variables Age, years Height, cm Weight, kg BMI, kg/m2 Waist circumference, cm Hip circumference, cm WHR Visceral fat, kg Percent body fat (%) FBG, mg/dl Insulin, µIU/ml Total cholesterol, mg/dl HDL-C, mg/dl LDL-C, mg/dl Triglycerides, mg/dl hs-CRP, mg/l HOMA-IR FSH, mIU/ml LH, mIU/ml Estradiol, pg/ml Free testosterone, ng/dl MIF, ng/ml

PCOS n = 90 Controls n = 80 22.33 ± 6.94 23.45 ± 5.49 161.79 ± 7.13 160 ± 5.69 61.42 ± 11.69 61.56 ± 7.47 23.52 ± 4.64 23.96 ± 2.94 81.10 ± 13.66 81.47 ± 10.62 102.37 0.79 5.24 33.90 86.64 13.67 167.10 53.40 98.80 107.40 1.49 2.93 5.87 8.47 71.56 48.80 14.16

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

6.44 0.13 2.18 9.53 6.23 5.75 33.30 10.90 31.20 47.30 0.50 1.25 0.62 0.78 11.67 17.39 1.59

103.37 0.78 4.33 31.33 85.37 11.34 166.60 53.90 100.60 109.50 0.56 2.58 6.02 8.58 74.40 22.13 10.39

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

pa 0.244 0.164 0.926 0.462 0.841

8.23 0.615 0.08 0.738 1.46 0.002* 8.52 0.068 6.01 0.180 5.10 0.006* 27.20 0.936 12.50 0.237 30.90 0.701 42.90 0.766 0.49

A possible link between luteinizing hormone and macrophage migration inhibitory factor levels in polycystic ovary syndrome.

Macrophage migration inhibitory factor (MIF) is a multifunctional cytokine that plays a role in metabolic and inflammatory processes. Increasing evide...
975KB Sizes 1 Downloads 12 Views