Alteração do ciclo menstrual na adolescência: manifestação precoce da Síndrome Metabólica?

Abstract

Evidences have appeared throughout the last decade that the metabolic syndrome(MS) (increasingly reported among teens) begins in intra-uterine life and its signs and symptoms are already present in adolescence. Nevertheless, specific diagnostic criteria for this age group are missing. The menstrual cycle represents the result of the normal functioning not only of the hypothalamus-hypophysis-ovarian axis (HHO), the uterus, and the genital apparatus, but also of the metabolic balance of the body. Menstrual cycle alterations may represent signs of imbalance and abnormality. MS is also linked to premature pubarche due to premature adrenarche and polycystic ovary syndrome (PCOS) characterized by an ovarian dysfunction oligoanovulação, hyperandrogenism and/or polycystic ovaries Insulin resistance (IR) has a central role in the pathophysiology and interrelation of components of MS and also of PCOS. Insulin resistance is compensated by increased insulin production by pancreatic beta cells. The compensatory hyperinsulinemia has consequences in the endothelium, inflammatory factors, glucose and lipid metabolism and affect the menstrual cycle by stimulating ovarian androgen, suppressing SHBG and possibly altering the pattern of pulsatile secretion of GnRH. These menstrual changes may present themselves at an early stage, before the metabolic changes of IR, so the careful assessment of the menstrual patterns of adolescents may represent a valuable warning sign for cardiovascular and metabolic risk. Evaluate the behavior of parameters of metabolic syndrome and its relation to the menstrual cycle in adolescents. Observational, transversal-cut study with 59 female adolescents between 12 and 19 years of age, and the presence of at least one of the following risk factors for MS; 1- Overweight, Obesity and Acanthosis Nigricans. All the adolescents underwent a clinical evaluation, with gathering of anthropometric data, and laboratory evaluation composed of: evaluation of fasting glucose, total cholesterol, HDL-cholesterol, triglycerides, Oral Glucose Tolerance Test after 120 minutes (Glucose-120), insulin pre-(fasting insulin), insulin post-OGTT-120 (insulin 120), Follicle-stimulating hormone (FSH), Luteinizing hormone (LH), Total Testosterone (TT), Androstenedione, Two groups were created. G-1 adolescents with irregular cycles G-2 with regular menstrual cycles. From the 59 adolescents evaluated, 36 formed G-1 and 23 formed G-2. The average gynecological age was 4,5 years, and of the menarche 11,3 years. In the statistical analysis of the differences in clinical and laboratory variables between the groups, it was observed that G-1 Waist(p=0,026),FastingInsulin(p=0,001),Glucose 120(p=0,002), Insulin 120 (p =0,0001), HOMA IR (p = 0,0008) , Triglyceride (p = 0,013), SM(p<0,0001) e SOP(p<0,001) significantly higher and QUICK (p=0,008),G/I (p=0,002) and HDL (p = 0,001) significantly lower than G-2. (88,8% of adolescents with irregular cycles in the past year showed irregularity since menarche). This study shows a significant association between menstrual irregularity, IR, MS and PCOS in this population. All adolescents diagnosed with MS had irregularity since menarche and of these 93.5% were diagnosed with PCOS.Our study draws attention to the behavior of the menstrual cycle in adolescence in relation to cardiovascular and metabolic risks, thus signaling that further studies need to be developed in this population.