Table 2.
Study characteristics of all patients who underwent a saline infusion test
| Variable | Patients with available data, n/n/n SIT+/SIT-/SITi | SIT positive | SIT negative | SIT inconclusive | P-valuea | P-valueb |
|---|---|---|---|---|---|---|
| Demographics | ||||||
| Male, n (%) | 9/59/6 | 4 (44.4) | 17 (28.8) | 3 (50.0) | 0.44 | 0.380 |
| Age, years, mean (SD) | 9/59/6 | 54.3 (9.2) | 51.4 (11.2) | 52.8 (4.6) | 0.40 | 0.717 |
| BMI, kg/m2, n (%) | 9/59/6 | 0.65 | 0.165 | |||
| ≤25 | 1 (11.1) | 15 (25.4) | 0 | |||
| >25–≤30 | 6 (66.7) | 27 (45.8) | 6 (100) | |||
| >30 | 2 (22.2) | 17 (28.8) | 0 | |||
| Smoking status, n (%) | 9/58/6 | 0.53 | 0.604 | |||
| Current | 2 (22.2) | 14 (24.1) | 1 (16.7) | |||
| Former | 1 (11.1) | 17 (29.3) | 3 (50.0) | |||
| Never | 6 (66.7) | 27 (46.6) | 2 (33.3) | |||
|
| ||||||
| Blood pressure, mean (SD) | ||||||
| Systolic BP, mmHg | 9/59/6 | 158.6 (10.2) | 163.9 (13.7) | 167.3 (12.5) | 0.20 | 0.417 |
| Diastolic BP, mmHg | 9/59/6 | 95.3 (9.1) | 97.0 (9.8) | 101.5 (10.3) | 0.62 | 0.462 |
| ABPM, mmHg | 2/13/1 | 166.5 (9.2) | 159.8 (18.6) | 171.0 (−) | 0.49 | 0.765 |
| ABPMday, mmHg | 1/12/1 | 161.0 (NA) | 162.8 (19.8) | 175.0 (−) | – | 0.833 |
| Home BP, mmHg | 0/1/0 | – | 160.0 (−) | – | – | – |
| Heart rate, beats/minute | 7/35/5 | 68.6 (12.8) | 76.5 (13.4) | 71.4 (13.6) | 0.17 | 0.313 |
|
| ||||||
| Biochemical parameters | ||||||
| Serum potassium, mmol/l, mean (SD) | 9/58/6 | 4.11 (0.26) | 4.38 (0.39) | 4.3 (0.2) | 0.02 | 0.121 |
| Serum sodium, mmol/l, mean (SD) | 9/58/6 | 141.7 (2.6) | 142.0 (2.1) | 141.3 (2.1) | 0.74 | 0.749 |
| Serum creatinine, µmol/l, mean (SD) | 9/58/6 | 75.8 (13.1) | 79.4 (13.5) | 88.2 (14.3) | 0.45 | 0.216 |
| Aldosterone, pmol/l, mean (SD) | 9/59/6 | 668.4 (118.1) | 592.3 (244.2) | 494.0 (94.5) | 0.15 | 0.345 |
| Renin, pmol/l, median (IQR) | 9/59/6 | 0.48 (0.34 to 0.68) | 0.67 (0.55 to 0.78) | 0.55 (0.38 to 0.62) | 0.04 | 0.023 |
| ARR, pmol/mU, mean (SD) | 9/59/6 | 105.3 (48.6) | 61.1 (19.9) | 75.9 (41.3) | 0.03 | <0.001 |
| Serum glucose, mmol/l, mean (SD) | 9/56/5 | 5.4 (0.5) | 5.1 (0.8) | 5.2 (0.5) | 0.27 | 0.665 |
|
| ||||||
| Cardiovascular morbidity, n (%) | ||||||
| OSAS | 9/59/6 | 0 | 0 | 0 | – | – |
| Atrial fibrillation | 9/59/6 | 0 | 0 | 0 | – | – |
| Stroke | 9/59/6 | 0 | 1 (1.7) | 0 | 1.00 | – |
| Myocardial infarction | 9/59/6 | 0 | 0 | 0 | – | – |
a
P-value: comparison of SIT positive and SIT negative.
b
P-value: comparison of SIT positive and SIT negative and SIT inconclusive. ABPM = systolic ambulatory blood pressure monitoring. ABPMday = daytime systolic ambulatory blood pressure monitoring. ARR = aldosterone-to-renin ratio. BMI = body mass index. Home BP = home systolic blood pressure. IQR = interquartile range. OSAS = obstructive sleep apnoea syndrome. SD = standard deviation. SIT = saline infusion test. SITi = saline infusion test with inconclusive result. Systolic BP = office systolic blood pressure.