Guo Meihan, Montero David
Faculty of Medicine, Hong Kong University, Hong Kong, China.
CardioVascular Institute and Division of Cardiology, Department of Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.
JACC Adv. 2025 Jan 8;4(2):101536. doi: 10.1016/j.jacadv.2024.101536. eCollection 2025 Feb.
Whether medium-term increased water intake alone, or in combination with co-adjuvant nonexercise interventions aimed to expand blood volume (BV), improve the human cardiovascular phenotype and cardiorespiratory fitness remains unexplored.
The purpose of this study was to determine the medium-term impact of increased (+40%) fluid (water) intake (IFI) or IFI plus head-up sleep (IFI + HUS) on BV and the cardiovascular phenotype in healthy individuals.
Healthy adults (n = 35, age 42 ± 18 years, 51% female) matched by sex, age, body composition, physical activity, and cardiorespiratory fitness were randomly allocated to IFI or IFI + HUS for 3 months. Body composition and BV were determined via DXA and indicator-dilution methods. Cardiac filling, output, and peak O consumption (VO) were assessed via high-resolution echocardiography and pulmonary gas analyses at rest and during incremental exercise.
Intravascular volumes, comprising plasma and red blood cell volumes, were not modified by IFI or IFI + HUS. Cardiac volumes at rest, specifically left ventricular (LV) end-diastolic volume and stroke volume (SV), and systolic emptying rate were increased after IFI and IFI + HUS ( ≤ 0.007); the effects on SV and systolic emptying rate were larger in IFI + HUS vs IFI ( ≤ 0.037). Arterial elastance and cardiac afterload were similarly reduced by IFI and IFI + HUS ( ≤ 0.006). Moreover, resting LV diastolic filling rate and lateral wall e' velocity were only increased after IFI + HUS ( ≤ 0.031). During exercise, neither SV, cardiac output, and peak VO were altered by IFI or IFI + HUS.
Medium-term increased water intake largely expands the resting volume and output of the LV while reducing arterial elastance and cardiac afterload, without altering intravascular volumes, cardiac or aerobic capacities. With the addition of HUS, relaxation properties of the resting LV are further improved.
仅中期增加饮水量，或与旨在扩充血容量（BV）、改善人体心血管表型和心肺适能的辅助非运动干预措施相结合，其效果仍未得到探索。
本研究旨在确定增加40%的液体（水）摄入量（IFI）或IFI加头高位睡眠（IFI + HUS）对健康个体BV和心血管表型的中期影响。
按性别、年龄、身体成分、体力活动和心肺适能匹配的健康成年人（n = 35，年龄42±18岁，51%为女性）被随机分配至IFI组或IFI + HUS组，为期3个月。通过双能X线吸收法（DXA）和指示剂稀释法测定身体成分和BV。通过高分辨率超声心动图和肺气体分析评估静息状态和递增运动时的心脏充盈、输出量和峰值耗氧量（VO）。
包括血浆和红细胞体积在内的血管内容量未因IFI或IFI + HUS而改变。静息时的心脏容积，特别是左心室（LV）舒张末期容积和每搏输出量（SV）以及收缩期排空率在IFI和IFI + HUS后增加（≤0.007）；IFI + HUS对SV和收缩期排空率的影响大于IFI（≤0.037）。IFI和IFI + HUS同样降低了动脉弹性和心脏后负荷（≤0.006）。此外，仅IFI + HUS后静息LV舒张充盈率和侧壁e'速度增加（≤0.031）。运动期间，IFI或IFI + HUS均未改变SV、心输出量和峰值VO。
中期增加饮水量在很大程度上扩大了静息时LV的容积和输出量，同时降低了动脉弹性和心脏后负荷，而未改变血管内容量、心脏或有氧能力。加上HUS后，静息LV的舒张特性进一步改善。
