Antihypertensive therapy: nocturnal dippers and nondippers. Do we treat them differently?

Chakrapani Mahabala,¹ Padmanabha Kamath,² Unnikrishnan Bhaskaran,³ Narasimha D Pai,² Aparna U Pai<sup>4

1</sup>Department of Medicine, Kasturba Medical College, Manipal University, Mangalore, Karnataka State, India; ²Department of Cardiology, Kasturba Medical College, Manipal University, Mangalore, Karnataka State, India; ³Department of Community Medicine, Kasturba Medical College, Manipal University, Mangalore, Karnataka State, India; ⁴Department of Radiodiagnosis, Vivekananda Institute of Medical Sciences, Kolkata, West Bengal State, India

Abstract: Hypertension is a major independent risk factor for cardiovascular diseases. Management of hypertension is generally based on office blood pressure since it is easy to determine. Since casual blood pressure readings in the office are influenced by various factors, they do not represent basal blood pressure. Dipping of the blood pressure in the night is a normal physiological change that can be blunted by cardiovascular risk factors and the severity of hypertension. Nondipping pattern is associated with disease severity, left ventricular hypertrophy, increased proteinuria, secondary forms of hypertension, increased insulin resistance, and increased fibrinogen level. Long-term observational studies have documented increased cardiovascular events in patients with nondipping patterns. Nocturnal dipping can be improved by administering the antihypertensive medications in the night. Long-term clinical trials have shown that cardiovascular events can be reduced by achieving better dipping patterns by administering medications during the night. Identifying the dipping pattern is useful for decisions to investigate for secondary causes, initiating treatment, necessity of chronotherapy, withdrawal or reduction of unnecessary medications, and monitoring after treatment initiation. Use of this concept at the primary care level has been limited because 24-hour ambulatory blood pressure monitoring has been the only method for documenting dipping/nondipping status so far. This monitoring technique is expensive and inconvenient for routine usage. Simpler methods using home blood pressure monitoring systems are evolving to document basal blood pressure in the night, which would help in greater acceptance and use of the concept of dipper/nondipper in managing hypertension at the primary care level.

Keywords: 24-hour ambulatory blood pressure monitoring, blood pressure variability, left ventricular hypertrophy, chronotherapy