Background
Hypertension (HTN) is often underdiagnosed and undertreated. Masked HTN reached 49% in chronic kidney disease (CKD) in children. The prevalence of HTN in adult systemic lupus erythematosus (SLE) varies from 30 to 77%. Limited studies with maximum of 20 participants in children with SLE demonstrated prevalence of blunted nocturnal dipping from 50 to 90%. Nocturnal HTN and blunted dipping are independent predictors for all-cause cardio-vascular morbidity/mortality, independent of 24-hr systolic blood pressure (BP) levels.
Objective
To assess ABPM pattern in SLE patients. Identify risk factors for abnormal nocturnal dipping.
Design/Methods
Cross-section, prospective, one center study. Patients (<30 years) with pediatric onset of SLE and normal or elevated BP were enrolled. Exclusion criteria were CKD < 30ml/min/1.73m2, daily prednisone dose > 20 mg, pregnancy and a history of obstructive sleep apnea. Variables included age, gender, ethnicity, BMI, CKD stage, SLE duration, SLEDAI-2K, proteinuria, prednisone dose, BP medications, ABPM parameters, Echocardiographic parameters. Fisher's exact and Student's test were used as appropriate.
Results
Of the 20 patients (17 F, 3 M), 11 were Hispanic and 6 African American. Normal kidney function with eGFR > 90 ml/min/1.73m2 were found in 17 patients, two had CKD stage 2, one had CKD stage 3 and mean age was 18.3 y (11-29y). Lupus nephritis was seen in 16 patients. BP was normal in 14 patients during the office visit and 13 patients were on BP medications. Correlation between hypertension class by office and ambulatory BP was poor with 2 patients with masked HTN, 2 unclassified patients with isolated elevated BP load. Additionally, 3 patients >18yo with controlled HTN had isolated elevated BP load. Blunted nocturnal dipping was seen in 11 patients, additionally 1 patient had hyper dipping and 1 - reverse dipping. Blood pressure abnormalities in total were found in 16 patients (80%). Echo was done for 14 patients. Left ventricular mass index (LVMi), relative wall thickness (RWT) and ejection fraction were normal in all patients. Left ventricle was dilated in 1 patient. Treatment changes were made after ABPM in 5 patients (25%). Obesity, SLE duration, SLE activity, renal involvement, proteinuria, use of steroids and antihypertensives did not differ significantly between the patients with and without abnormal dipping.
Conclusion
Abnormal dipping and masked HTN is common in children, adolescents and young adults with SLE and can be missed if ABPM is not applied in clinical practice. No difference in obesity, SLE duration, SLE activity, renal involvement, proteinuria, use of steroids and antihypertensives were found between groups with normal and abnormal nocturnal dipping.
