TABLE 2.
Aggregated measurements across astronauts.
| Measurement (fluid) a | Count b | F,R, PR trends c,d | Physiological aspects |
|---|---|---|---|
| Pyridinium (PYD) Cr | 21 | ↑ ↑ ↑ | Bone resorption (Caillot-Augusseau et al., 1998; Smith et al., 1998; Smith et al., 2015) |
| Sodium (urine) | 20 | −− ↓ (↑ ↓ −) | Saline ingestion pre-landing |
| Zinc (serum) | 19 | ↑ ↓ ↓ (↓ ↓ ↓) | Nausea; bone resorption (Cann and Adachi, 1983); immune response, wound healing (National Institutes of Health, Office of Dietary Supplements., 2022) |
| Urine volume 24 h | 19 | ↓ ↓ ↓ (↓ ↑ −) | Inadequate fluid intake; fluid redistribution; renal stones (Smith et al., 2015) |
| Potassium (urine) | 19 | ↓ ↓ ↓ (↑ ↓ ↓) | Retention - renal stones; muscle disuse (Lane et al., 2000) |
| Iron (serum) | 19 | ↑ ↓ ↓ (−↓ ↓) | Iron metabolism; immune response (Dallman, 1987; Alfrey et al., 1997) |
| Blood pressure diastolic | 19 | ↓ ↑ − | Hypotension; conditioning (Fu et al., 2019) |
| 25-OH Vitamin D | 19 | ↓ ↓ ↓ | Bone mass resorption (Smith et al., 2005b) |
| 3-methylhistidine (urine) Cr | 19 | ↓ ↓ ↑ (−↑ −) | Skeletal muscle maintenance (Young and Munro, 1978) |
| Sodium | 18 | ↓ − − (↑ − ↑) | Fluid imbalance; diet |
| Creatinine (serum) | 18 | ↓ ↓ ↓ (↑ − −) | Muscle mass; diet (Wyss and Kaddurah-Daouk, 2000; Delanaye et al., 2017) |
| Chloride (urine) | 18 | −↓ ↓ (↑ ↓ −) | Dietary salt; saline ingestion (end of mission); intravenous saline at landing |
| Blood pressure systolic | 18 | ↓ ↑ − | Hypotension; conditioning (Fu et al., 2019) |
| Vitamin B12 | 17 | ↓ ↓ ↓ (↑ ↑ −) | Food absorption, neurological manifestation, ocular health (Chu and Scanlon, 2011; Green et al., 2017; Smith et al., 2021) |
| Transferrin receptors | 17 | ↓ ↓ ↑ | Iron metabolism shifts (Smith et al., 2005b) |
| Sulfate (urine) | 17 | ↓ ↓ ↓ (↑ ↑ ↑) | Urinary supersaturation; diet |
| pH (urine) | 17 | ↓ ↓ ↓ (↑ ↑ −) | Kidney issues; renal stones (Smith et al., 2015) |
| Monocytes % | 17 | ↓ ↓ − | Immunity; viral reactivation |
| Magnesium (serum) | 17 | ↑ ↓ − (↓ ↓ −) | Decreased intake; renal stones (Smith et al., 2005b) |
| CD8+ true naïve % | 17 | ↓ ↓ ↓ | T cell maturation dysregulation (Crucian et al., 2015) |
| Phosphorus (urine) | 16 | ↓ ↓ ↓ (↑ ↓ −) | Renal; skeletal (Smith et al., 2005b; National Institutes of Health, Office of Dietary Supplements, 2021; Smith et al., 2021) |
| γ-carboxyglutamic acid Cr | 16 | −↑ ↑ (↓ ↓ ↑) | Vitamin K status (Furie et al., 1999; Caillot-Augusseau et al., 2000; Zwart et al., 2011) |
| Calcium (serum) | 16 | ↓ ↓ ↓ (↓ ↑ −) | Bone metabolism; renal stone risk (Smith et al., 2015) |
a Cr: normalized using creatinine.
b Count of individuals for which measurement has a statistically significant trend.
c The majority signal intensity trend is summarized with respect to preflight for: Flight (F), Return date (R), Post-return (PR) sequentially. If a secondary trend is observed it is listed in the parenthesis.
d The intensity trends are: same as preflight (−), higher intensity (↑), or lower intensity (↓).