Non-dipping pattern in early-stage diabetes: association with glycemic profile and hemodynamic parameters

Patients with longstanding diabetes exhibit diminished nocturnal blood pressure (BP) drop, yet this phenomenon remains understudied in the early stages of the disease. Eighty patients with newly diagnosed (<6 months) Diabetes Mellitus type 2 (T2DM) and 80 non-T2DM individuals underwent office and 24-h ambulatory BP measurements, estimation of hemodynamic parameters using impedance cardiography and blood tests. Ten-year atherosclerotic cardiovascular disease (ASCVD) risk score was calculated. T2DM patients exhibited higher nighttime systolic blood pressure (SBP) (p = 0.028) and lower dipping (p < 0.001) compared to controls. In the total population, dipping correlated negatively with age, HbA_1c, ASCVD risk score, and positively with HDL Cholesterol and Velocity Index (VI), a marker of myocardial contractility (p < 0.05). Nighttime SBP correlated positively with ASCVD risk, BMI, HbA_1c, fasting glucose, eGFR, and negatively with VI (p < 0.05). After adjustment for other variables, HbA_1c (p = 0.03), eGFR (p = 0.02) and VI (p = 0.004) independently predicted non-dipping. Multivariate analysis revealed HbA_1c (p = 0.023), eGFR (p = 0.05), and VI (p = 0.006) as independent predictors of nighttime SBP. Patients diagnosed with T2DM concurrently present impaired circadian BP rhythm, which appears to be directly associated with impaired glycemic profile. The observed association with myocardial contractility might represent an additional mechanism for the aggravated cardiovascular risk in these patients.