BACKGROUND: To study the relationship between cortisol, insulin, and thyroid hormone levels with 24-h urinary sodium (Na) excretion levels in essential hypertensive patients.

METHODS: All patients underwent history taking, physical examination, blood pressure (BP) measurement, 12 lead electocardiographic evaluation, routine urine analysis, biochemical analysis including measurement of cortisol, insulin, and thyroid hormone levels, 24-h urine collection to measure urinary Na and protein excretion and creatinine clearance.

RESULTS: In total, 68 newly diagnosed hypertensive patients were included. Spearman correlation analysis revealed that 24-h urinary Na excretion was correlated with insulin levels
(ρ = −0.473, P < 0.0001), serum cortisol levels (ρ = −0.404, P= 0.0010) and creatinine clearance (ρ = 0.407, P: 0.0010). Linear regression of independent factors has revealed that systolic BP
(B = 0.004, CI = 0.001-0.008, P = 0.0170), body mass index (B = 0.014, CI = 0.005-0.023,
P = 0.0030), being male (B = 0.077, CI = 0.001-0.153, P = 0.0480), creatinine clearance
(B = 0.003, CI = 0.001-0.006, P = 0.0120) and insulin levels (B = −0.008, CI = −0.014 to −0.002, P = 0.0070) were independently related with logarithmically converted 24-h Na excretion.

CONCLUSION: In conclusion, we found that insulin but not cortisol and thyroid hormone levels were independently related with 24-h urinary Na excretion in newly diagnosed essential hypertensive patients.

Keywords: Cortisol, Hypertension Insulin, Sodium, Thyroid