Table 1.
Descriptive characteristics of participants at admission, stratified by hydration status.
| All n = 358 (100%) |
Underhydrated n = 209 (58.4%) |
Euhydrated n = 149 (41.6%) |
p value1 | |
|---|---|---|---|---|
| Age, years, Me (IQR) | 82 (78–86) | 82 (78–86) | 82 (77–86) | 0.33 |
| Gender | ||||
| Male, n (%) | 84 (23.5) | 48 (23.0) | 36 (24.2) | 0.80 |
| Female, n (%) | 274 (76.5) | 161 (77.0) | 113 (75.8) | |
| Living in long term care, n (%) | 11 (3.1) | 7 (3.3) | 4 (2.7) | 1.0 |
| Living alone, n (%) | 105 (30.3), n = 347 | 64 (31.7), n = 202 | 41 (28.3), n = 145 | 0.55 |
| Hospitalization in the last year, n (%) | 98 (27.6), n = 355 | 55 (26.6), n = 207 | 43 (29.1), n = 148 | 0.63 |
| Number of chronic diseases, Me (IQR) | 5.0 (3.0–6.0) | 5.0 (4.0–6.0) | 4.0 (3.0–6.0) | 0.001 |
| Multimorbidity, n (%) | 210 (58.7) | 134 (64.1) | 76 (51.0) | 0.02 |
| Number of medications, Me (IQR) | 7.0 (5.0–9.0), n = 350 | 7.0 (5.0–10.0), n = 206 | 7.0 (4.0–9.0), n = 144 | 0.01 |
| Polypharmacy, n (%) | 275 (78.6) | 172 (83.5) | 103 (71.5) | 0.008 |
| Barthel Index, Me (IQR) | 90 (70–100), n = 356 | 90 (70–100), n = 208 | 90 (65–100), n = 148 | 0.48 |
| IADL, Me (IQR) | 7.0 (2.0–11.0), n = 352 | 7.0 (2.0–11.0), n = 206 | 7.0 (1.75–11.0), n = 146 | 0.55 |
| AMTS, Me (IQR) | 8.0 (6.0–9.0), n = 332 | 8.0 (6.0–9.0), n = 196 | 8.0 (6.0–9.0), n = 136 | 0.88 |
| GDS, Me (IQR) | 6.5 (3.0–10.0), n = 320 | 6.0 (3.0–10.0), n = 188 | 7.0 (4.0–10.0), n = 132 | 0.32 |
| MNA-SF, Me (IQR) | 11.0 (9.0–13.0), n = 349 | 12.0 (9.0–13.0), n = 203 | 11.0 (9.0–13.0), n = 146 | 0.26 |
| CFS, Me (IQR) | 5.0 (4.0–6.0) | 5.0 (4.0–6.0) | 5.0 (4.0–5.5) | 0.69 |
| Osmolarity, mMol/ L, Me (IQR) | 292.9 (288.4–296.0) | 295.4 (293.6–298.4) | 287.7 (283.8–289.6) | <0.001 |
| Serum sodium, mmol/L, Me (IQR) | 140.0 (138.0–141.0) | 141.0 (140.0–142.0) | 138.0 (136.0–139.0) | <0.001 |
| Na < 135 mmol/ L | 24 (6.7) | 4 (1.9) | 20 (13.4) | <0.001 |
| Serum potassium, mmol/L, M (SD) | 4.43 (0.46) | 4.50 (0.46) | 4.33 (0.44) | 0.001 |
| Serum urea, mmol/ L, Me (IQR) | 6.9 (5.5–8.8) | 7.8 (6.2–9.9) | 5.8 (4.9–7.3) | <0.001 |
| Serum glucose, mmol/L, Me (IQR) | 5.5 (5.0–6.3) | 5.6 (5.2–6.7) | 5.3 (4.9–5.8) | <0.001 |
| Serum creatinine, mmol/L, Me (IQR) | 86.2 (74.3–107.2), n = 354 | 91.05 (77.8–115.8), n = 207 | 78.7 (69.8–96.4), n = 147 | <0.001 |
| eGFR, ml/min/1.73m2, M (SD) | 57.8 (17.1), n = 354 | 58.2 (16.8), n = 207 | 58.4 (16.7), n = 147 | 0.91 |
Underhydrated refers to subjects with serum calculated osmolarity > 295 mMol/L. 1—p values were determined by using a t-test for independent samples or Mann–Whitney test (continuous or interval variables) and χ2 test or Fisher exact test, as appropriate (categorical variables) to compare participants categorized according to hydration status. AMTS, Abbreviated Mental Test Score; CFS, 7-point Clinical Frailty Scale level; eGFR, glomerular filtration rate; GDS, 15 items Geriatric Depression Scale; IADL, instrumental activities of daily living; IQR, interquartile range; M, mean; Me, median; MNA-SF, Mini Nutritional Assessment-Short Form; n, number of cases; Na, sodium; SD, standard deviation. Bold signifies a statistically significant value.