Padrão do ciclo menstrual na adolescência e sua relação com parâmetros de resistência à insulina, síndrome metabólica e síndrome dos ovários policísticos

Abstract

Although adolescence is a healthy time of life, insulin resistance (IR) and its consequences may appear during this period, generally discovered at a later stage when obesity, metabolic syndrome (MS) and / or polycystic ovary syndrome (PCOS) are already established. During the past few years, some studies have shown that menstrual irregularity is an easy-to-observe parameter that may reflect endocrinal diseases and metabolic alterations. In order to assess the importance of menstrual irregularity as a risk indicator for IR, MS and PCOS, in addition to identifying possible associated clinical and laboratory markers, we conducted a cross-sectional observational study of eighty adolescents with a gynecological age (GA) of >01 year. Chronological age, GA and BMI were respectively, 15.0±1.4 years, 2.85±1.64 years and 26.4±8.1. The group with menstrual irregularity (52.5% of the sample) presented significantly higher levels for BMI, blood pressure, waist circumference, fasting insulin, insulin after overload (insulin 120), triglycerides (TG), HOMA-IR, G/I and androgens, associated with significant reductions in SHBG, HDL-C and QUICKI, compared to the group with regular cycles. MS was diagnosed in 38.1% of girls with menstrual irregularity versus 0% with regular cycles, with confirmed diagnoses of PCOS in 83.3% of adolescents with menstrual alterations. The analysis of the subgroup with normal BMI showed that girls with menstrual irregularity presented significantly higher insulin 120, TG and androgens, together with low HDL-C and SHBG levels, compared to those with regular cycles. An analysis of the subgroup with GA &#8804; 02 years showed that girls with menstrual irregularity already presented significantly higher BMI, waist circumference, SBP, acne, <i>acanthosis nigricans</i>, insulin 120, TG and serum androgens, with significantly lower HDL-C and SHBG. Diagnoses of PCOS and MS were more prevalent in this group. A logistic regression analysis showed that SHBG was the independent variable that best explained menstrual irregularity in the general population of the study and the subgroup of adolescents with GA&#8804; 02 years. However, in the subgroup with GA> 02 years, the independent variable was represented by QUICK. In conclusion, our results showed that menstrual irregularity is an early predictive sign of risk for IR, MS and PCOS among adolescents with a gynecological age &#8804; 02 years and normal BMI. Observation of menstrual cycle patterns during the first few years after the menarche, together with androgens, SHBG and insulin sensitivity measurements (especially insulin 120), may contribute to early detection of endocrinal and metabolic disorders, thus paving the way for preventive steps minimizing cardiovascular risks.