Utilidad de la antropometría y la vitamina D en la salud sexual y reproductiva de las mujeres

Abstract

INTRODUCTION: Body composition, more than body weight, is related to the origin of obesity, as well as metabolism and hormonal disorders. Anthropometry, according to the International Society for the Advancement of Kinanthropometry (ISAK), allows estimating the total amount of subcutaneous fat, being a method of analyzing body composition. It can be remarked its methodological simplicity, low cost and non-invasive nature. Women of childbearing age undergo important changes at the hormonal level, in the different stages of their lives: menarche, fertile stage, pregnancy and even menopause. During these stages, with their associated hormonal changes a body composition is developed that can be variable depending on the individual, whose role and relationship with the hormonal profile is still under investigation. The objectives of this study are to clarify the relationship between body composition measured by anthropometry and PCOS, to investigate the reproducibility of the anthropometric method during pregnancy, changes in body composition during pregnancy, as well as fundamental aspects such as the presence of vitamin D and its impact in the birth process. MATERIAL AND METHODS: The data of the pregnant patients were obtained from an observational, longitudinal, prospective study of cohorts in the Obstetrics Service of the Clinical University Hospital Virgen de la Arrixaca, Murcia (Spain). Recruitment was carried out from March 2016 to September 2019. 208 pregnant women recruited in the first routine control ultrasound were included. A visit was made for each trimester of pregnancy. At the 1st visit (8-13 weeks' gestation), blood was drawn for hormonal determinations: total and free testosterone, androstenedione, progesterone, estradiol, DHEA, vitamin 25(OH)D, AMH, and glucose. During the three control visits of the study, a complete anamnesis, physical activity questionnaire in each trimester (IPAQ short version) and complete anthropometric profile were also recorded according to the ISAK protocol. Eight skinfolds (triceps, subscapular, biceps, supraspinal, iliac crest, abdominal, 7 mid-thigh, and calf) were measured, considering different summatory for fat mas calculations. In addition, after delivery, the end of pregnancy, spontaneous termination or induction, eutocic delivery, instrumented delivery or cesarean section was recorded, as well as whether or not an episiotomy was required. A statistical analysis was performed to relate vitamin D levels at the beginning of pregnancy, adjusted according to the season of the year, with the incidence of eutocic delivery, instrumental delivery, presence or absence of episiotomy, as well as cesarean section. Data of the patients with PCOS were extracted from an observational study of cases and controls in the Gynecology Service of the Hospital Clínico Universitario Virgen de la Arrixaca in Murcia (Spain), between September 2014 and May 2016. The diagnosis of PCOS was established when the patient met at least 2 of the 3 Rotterdam criteria. All the women underwent anamnesis, a hormonal blood test, androgenic profile, lipid profile, insulin levels, insulin resistance, and an anthropometric study according to the ISAK protocol. A statistical analysis was performed to evaluate the differences in body composition between patients with and without PCOS, as well as to examine associations between lipid profile (TG, HDL-c, LDL-c, total cholesterol), HOMA-IR and body composition (lean, fat and bone mass) in both groups. RESULTS: In patients with PCOS we found significantly higher percentages of fat mass compared to controls (p=0.012). Regarding the glycemic and lipid profiles, women with PCOS had significantly higher levels of testosterone (p< 0.001), higher LDL-c (p = 0.001), lower HDL-c (p < 0.001), and higher HOMA-IR levels (p = 0.001). Multivariate analysis showed that in patients with PCOS, when adjusting for fat mass, they lost their significant association with TG, HDL-c and LDL-c. However, PCOS remained associated with higher HOMA-IR regardless of the effect of body composition. In pregnant women, the increase in body fat and its distribution during the three trimesters of pregnancy was analyzed through anthropometric measurements of skinfold thicknesses. A general increase in fat mass was observed, measured by the sum of skinfolds (p = 0.003), with an increase in the arms (p = 0.046), trunk (p = 0.019) and legs (p = 0.001). The analysis of the coefficient of variation and its propagated error showed 8 that the measurement of skinfolds during pregnancy is a reproducible method. As a limitation, the density of the propagated error showed difficulty and decreased consistency in trunk measurements during the 3rd trimester of pregnancy, decreasing their reproducibility and therefore reliability. According to vitamin D, mean maternal blood vitamin D levels during the 1st trimester were 21.58 ng/mL. (DS 7.29), with 44.3% in a situation of vitamin D deficiency (30 ng /ml in early pregnancy. According to the analyzes carried out, no statistical relationship was found between adjusted vitamin D levels and the risk of ending labor by eutocic delivery in three clinical situations: instrumental delivery (OR 1.05 [0.97, 1.13]), primary cesarean section, mainly including those caused by nonprogression of labor and pelvifetal disproportion (OR 0.99 [0.88, 1.11]) and caesarean section for any other cause (OR 1.04 [0.95, 1.14]. CONCLUSION: The measurement of body composition by anthropometry is a simple and reproducible tool with utility in different pathologies and vital situations. In those patients with PCOS, the fat mass estimated by anthropometry is related to a worse metabolic profile. In addition, the presence of PCOS is related to worse HOMA-IR regardless of body composition. In pregnant patients, the measurement of body composition by anthropometry has proven to be a reliable and reproducible method, which could be used within early diagnosis and prevention programs to reduce the percentages of fat mass and thus reduce the risk of long-term morbidities associated with obesity. Finally, vitamin D levels at the beginning of pregnancy have not been shown to be related to the mode of delivery.