Haditsch Bernd, Roessler Andreas, Krisper Peter, Frisch Herwig, Hinghofer-Szalkay Helmut G, Goswami Nandu
Institute of Physiology, Center of Physiological Medicine, Medical University of Graz, Harrachgasse 21, 8010, Graz, Austria.
Department of Internal Medicine, Division of Nephrology, Medical University of Graz, Auenbruggerplatz 27, 8036, Graz, Austria.
PLoS One. 2015 Mar 5;10(3):e0118730. doi: 10.1371/journal.pone.0118730. eCollection 2015.
We investigated changes in volume regulating hormones and renal function at high altitudes and across gender.
Included in this study were 28 subjects (n = 20 males; n = 8 females. ages: 19 - 65 yrs), who ascended to a height of 3440m (HA1), on the 3rd day and to 5050m (HA2), on the 14th day. Plasma and urinary creatinine and urinary osmolality as well as plasma levels of plasma renin activity (PRA), Aldosterone, antidiuretic hormone (ADH), and atrial natriuretic peptide (ANP) were measured. The plasma volume loss (PVL) was estimated from plasma density and hematocrit. Glomerular filtration rate (GFR) was measured based on nocturnal (9 hour) creatinine clearance; this was compared with various methods for estimation of GFR.
The mean 24-hour urine production increased significantly in both sexes across the expedition. But PVL reached significance only in males. No changes in Na+ in plasma, urine or its fractional excretion were seen at both altitudes. Urinary osmolality decreased upon ascent to the higher altitudes. ADH and PRA decreased significantly at both altitudes in males but only at HA2 in females. However, no changes in aldosterone were seen across the sexes and at different altitudes. ANP increased significantly only in males during the expedition. GFR, derived from 9-h creatinine clearance (CreaCl), decreased in both sexes at HA1 but remained stable at HA2. Conventional Crea[p]-based GFR estimates (eGFR) showed only poor correlation to CreaCl.
We report details of changes in hormonal patterns across high altitude sojourn. To our knowledge we are not aware of any study that has examined these hormones in same subjects and across gender during high altitude sojourn. Our results also suggest that depending on the estimation formula used, eGFR underestimated the observed decrease in renal function measured by CreaCl, thus opening the debate regarding the use of estimated glomerular filtration rates at high altitudes.
我们研究了高海拔地区以及不同性别间容量调节激素和肾功能的变化。
本研究纳入了28名受试者（n = 20名男性；n = 8名女性。年龄：19 - 65岁），他们在第3天上升至3440米高度（HA1），并在第14天上升至5050米高度（HA2）。测量了血浆和尿肌酐、尿渗透压以及血浆肾素活性（PRA）、醛固酮、抗利尿激素（ADH）和心房利钠肽（ANP）的血浆水平。根据血浆密度和血细胞比容估算血浆容量损失（PVL）。基于夜间（9小时）肌酐清除率测量肾小球滤过率（GFR）；并将其与估算GFR的各种方法进行比较。
在整个考察期间，男女两性的平均24小时尿量均显著增加。但PVL仅在男性中具有统计学意义。在两个海拔高度，血浆、尿液中的钠及其分数排泄均未见变化。上升至更高海拔时，尿渗透压降低。男性在两个海拔高度的ADH和PRA均显著降低，但女性仅在HA2时降低。然而，在不同性别和不同海拔高度，醛固酮均未见变化。在考察期间，ANP仅在男性中显著增加。源自9小时肌酐清除率（CreaCl）的GFR在HA1时男女两性均降低，但在HA2时保持稳定。基于传统肌酐清除率（Crea[p]）估算的GFR（eGFR）与CreaCl的相关性较差。
我们报告了高海拔停留期间激素模式变化的详细情况。据我们所知，尚无任何研究在同一受试者的高海拔停留期间对这些激素进行跨性别研究。我们的结果还表明，根据所使用的估算公式，eGFR低估了通过CreaCl测量的肾功能观察到的下降，从而引发了关于在高海拔地区使用估算肾小球滤过率的争论。
