Association between Growth Differentiation Factor 15 and Non-Dipping Circadian Pattern in Patients with Newly Diagnosed Essential Hypertension

Objective: Non-dipper hypertension (HT) confers greater risk compared with dipper HT. Growth differentiation factor 15 (GDF-15) recently emerged as a novel and independent marker of cardiovascular disease, both in diagnostic and prognostic scopes. Our aim was to evaluate the relationship of circadian blood pressure (BP) pattern with serum GDF-15 level in newly diagnosed HT patients without left ventricular hypertrophy. Subjects and Methods: Newly diagnosed non-dipper (n = 66) and dipper (n = 60) HT patients were selected according to 24-h ambulatory BP monitoring (ABPM). The controls comprised healthy normotensive subjects (n = 31). Data was collected through physical examination, laboratory analysis, ABPM, and echocardiography. GDF-15 was measured using ELISA. Results: Greater GDF-15 level was found in the non-dippers compared with the dippers and the controls (557.53 ± 91.7, 513.79 ± 62.86, and 494.44 ± 79.30 ng/L, respectively, p < 0.001). In bivariate linear correlation analysis, GDF-15 correlated positively with glomerular filtration rate (r = 0.180, p =0.030), total cholesterol (r = 0.170, p = 0.038), septal E/E′ ratio (r = 0.344, p = 0.001), lateral E/E′ ratio (r = 0.366, p < 0.001), nighttime systolic BP (r = 0.166, p = 0.046), and nighttime diastolic BP (r = 0.188, p = 0.024); however, it correlated negatively with septal and lateral E′ velocities (r = 0.268, p = 0.005 and r = 0.236, p = 0.013, respectively). Furthermore, GDF-15 level and nighttime diastolic BP remained independently associated with non-dipper HT. In ROC analysis, optimal cutoff value for GDF-15 was 524.6 ng/L with 56.7% sensitivity and 72.4% specificity (AUC: 0.676, 95% CI: 0.580–0.772, p < 0.05). Conclusion: Our results showed GDF-15 upregulation in the non-dipper HT group. GDF-15 and nighttime diastolic BP were independently associated with the non-dipping pattern. This study may suggest possible utilization of GDF-15 in the prediction of non-dipper HT.