IJCS | Volume 31, Nº3, May/ June 2018

275 Camargo et al. Manual lymphatic drainage, natriuresis and lipolysis International Journal of Cardiovascular Sciences. 2018;31(3)274-281 Original Article In women, water and electrolyte balance is influenced by ovarian hormones, whose receptors are located in reproductive tissues and in those involved in body fluid regulation, such as hypothalamus, cardiovascular systemand renal tubules. These hormones affect capillary dynamics, by increasing renal sodium reabsorption and influencing plasma volume. 2,3 Stachenfeld & Taylor 4 showed that estradiol increased plasma volume by its effect on capillary endothelial permeability, decreasing the outflow of proteins and water, without affecting extracellular fluid volume. Estrogen can affect capillary filtration and permeability, be it by direct action on capillary endothelium or indirectly by compounds like the atrial natriuretic peptide (ANP) and nitric oxide. 4 ANP is an important hormone stored in secretory granules of atrial cells, contributing to water-electrolyte balance. Its secretion depends on atrial distension caused by an increase in venous return, mechanical distension or hypernatremia, which lead to increased natriuresis combined with osmotic diuresis and vasodilation, relaxation of vascular smooth muscle of small arteries, arterioles and metarterioles, and hypotension. Besides, ANP inhibits renin, aldosterone and vasopressin release; it exerts a strong vasodilating action in the kidneys, contributing to increased blood flow and glomerular filtration rate, resulting in natriuresis and increased urine flow. 5 In adipocytes, ANP induces lipolysis via cyclic guanosine monophosphate (cGMP), resulting in activation of protein kinase G type I (GK-I), and degradation of triglycerides by perilipin A and hormone- sensitive lipase (HSL). 6 Nelson et al. 7 examined plasma concentration of glycerol and its urinary excretion in 12 young, healthy, trained men. The authors found that plasma glycerol peak concentration coincided with its peak in urinary excretion. Krupek et al. 8 evaluated urinary glycerol before and after twelve sessions of MLD in 3 young healthy women. Urinary glycerol was not increased in this study. Data on the effects of MLD on natriuresis and lipolysis are scarce and conflicting. Our aim was to assess the acute effect of MLD on natriuresis and lipolysis in young women using or not oral contraceptives. Material and methods According to the regulations of researches involving human subjects (resolution number 466/2012, Brazilian National Health Council), the study was approved by the Research Ethics Committee of the School of Medical Sciences/University of Campinas (CAAE: 24537613.2.0000.5404), Brazilian Registry of Clinical Trials -45c8br. All participants signed the informed consent form. Sample size was calculated based on a pilot study. GraphPad Statmate software, version 2 was used for calculation of 95% confidence interval and power of 80%. Thus, for statistical power of the sample be considered relevant, 30 volunteers per group would be necessary. This calculation was performed by Prof. Maria Imaculada de Lima Monteselo, specialist in the area. Twenty-nine women, non-users of oral contraceptives (nOCPu 21.5 ± 0.6 years BMI 21.3 ± 0.5 kg/m 2 ) and 29 oral contraceptive users (OCPu 21.4 ± 0.5 years, BMI 21.8 ± 0.4 kg/m 2 ), sedentary (international physical activity questionnaire, IPAQ-v8), 9 self-reported as healthy, and taking no medications except for OCP were enrolled. Women of the nOCPu group were included in luteal phaseofmenstrual cycle,whereaswomen of the OCPu group in the “rest period” from the OCP. All procedures were performed with volunteers at rest, in supine position, without fluid ingestion in a temperature-controlled room (22-24ºC) and relative humidity between 40 and 60% in the morning. For maintenance of resting metabolism, all volunteers received a standardized diet composed of one Brazilian nut, one nut, two apricots and six almonds without salt or sugar added. MLD procedure MLD was performed by the same physiotherapist as proposed by Leduc and Leduc10 Volunteers underwent a 45-minute session on abdomen and lower limbs. 11 Participants had previously received instructions for the procedure. First, in the abdomen, MLD of axillary lymph nodes was done by 10 strokes (clearing motions). Anterior abdominal wall was drained to two directions – the region above the umbilicus was drained toward the axilla, whereas the region below umbilicus was drained toward the inguinal lymph nodes – and thereby the inguinal lymph nodes were drained before the lower abdominal region. Following drainage of axillary and inguinal regions, 10 movements in each region were performed, beginning from the region closer to corresponding lymph nodes toward distal region. And finally, another movement in the opposite direction, i.e., from the distal toward proximal lymph nodes followed by 10 strokes on axillary lymph nodes were performed.