Table 1.

Baseline characteristics of the study populationa

CharacteristicNormotensive Control(n = 113)Essential Hypertension(n = 323)Primary Aldosteronism
All Patients(n = 56)Adrenal Adenoma(n = 30)Idiopathic(n = 26)
Clinical characteristics
    age (yr)52 ± 1252 ± 952 ± 1154 ± 1252 ± 13
    female/male gender (n [%])37/76 (33/67)103/220 (32/68)16/40 (29/71)8/22 (27/73)8/18 (31/69)
    BMIb26.8 ± 3.528.1 ± 3.128.5 ± 3.628.5 ± 3.628.4 ± 3.7
    SBP (mmHg)c130 ± 12166 ± 18167 ± 15167 ± 14166 ± 18
    DBP (mmHg)c79 ± 8103 ± 8103 ± 8103 ± 8103 ± 9
    estimated duration of hypertension (yr)10 ± 610 ± 610 ± 69 ± 5
Laboratory parameters
    plasma sodium (mmol/L)139 ± 3140 ± 3141 ± 2141 ± 2141 ± 3
    plasma potassium (mmol/L)4.4 ± 0.34.2 ± 0.43.2 ± 0.4d3.2 ± 0.4d3.3 ± 0.5d
    urinary sodium (mmol/24 h)118 ± 53111 ± 46104 ± 50101 ± 45109 ± 57
    urinary potassium (mmol/24 h)46 ± 2245 ± 1851 ± 1952 ± 2049 ± 17
    plasma active renin (pg/ml)e8.9 ± 9.99.4 ± 10.94.8 ± 6.54.6 ± 5.55.0 ± 7.6
    plasma aldosterone (pg/ml)f129 ± 74154 ± 99249 ± 193264 ± 180233 ± 207
    serum creatinine (μmol/L)84 ± 2298 ± 3990 ± 1990 ± 1989 ± 20
    creatinine clearance (ml/min per 1.73 m2)g97 ± 1789 ± 34106 ± 31105 ± 30108 ± 33
    urinary albumin/creatinine ratio (median [IQR])h0.008 (0.002 to 0.019)0.045 (0.017 to 0.084)0.046 (0.021 to 0.086)0.046 (0.020 to 0.086)0.047 (0.019 to 0.078)
  • a Data are means ± SD unless otherwise indicated. BMI, body mass index; DBP, diastolic BP; IQR, interquartile range; SBP, systolic BP.

  • b BMI is defined as the weight in kilograms divided by the square of the height in meters.

  • c BP was measured after appropriate washout of antihypertensive drugs as referred to in text.

  • d Values are those that were measured before correction with oral supplementation.

  • e Plasma active renin was lower in patients with primary aldosteronism than in patients with essential hypertension (P = 0.002).

  • f Plasma aldosterone was higher in patients with primary aldosteronism than in patients with essential hypertension (P < 0.001) and normotensive individuals (P < 0.001).

  • g Creatinine clearance was higher in patients with primary aldosteronism than in patients with essential hypertension (P < 0.001) and normotensive individuals (P = 0.016).

  • h Urinary albumin excretion was higher in patients with primary aldosteronism than in patients with essential hypertension (P = 0.019).