<p>Isolated Nocturnal Hypertension: What Do We Know and What Can We Do?</p>

Abstract

Nocturnal hypertension has been recognized as a significant risk factor for cardioand cerebrovascular diseases. Blood pressure (BP) monitoring significantly increased our awareness of nocturnal hypertension and studies revealed its influence on target organ damage. Nocturnal hypertension is associated with nonphysiological 24-h BP patterns, which consider inadequate drop or even increment of nighttime BP in comparison with daytime BP (nondipping and reverse dipping). Nevertheless, investigations showed that nocturnal hypertension was a predictor of adverse outcome independently of circadian BP pattern. There are still many uncertainties regarding diagnosis, mechanisms and treatment of nocturnal hypertension. There is a small difference between American and European guidelines in cutoff values defining nocturnal hypertension. Pathophysiology is also not clear because many conditions such as diabetes, metabolic syndrome, obesity, sleep apnea syndrome, and renal diseases are related to nocturnal hypertension and nonphysiological circadian BP pattern, but mechanisms of nocturnal hypertension still remain speculative. Therapeutic approach is another important issue and chronotherapy provided the best results so far. There are studies which showed that some groups of antihypertensive medications are more effective in regulation of nocturnal BP, but it seems that the timing of drug administration has a crucial role in the reduction of nighttime BP and conversion of circadian patterns from nonphysiologic to physiologic. Follow-up studies are necessary to define clinical benefits of nocturnal BP reduction and restoring unfavorable 24-h BP variations to physiological variant.

Isolated nocturnal hypertension: an unsolved problem—when to start treatment and how low should we go?

“…ABPM appears to be the only valid method that can interpret diurnal rhythm. This is important because patients with non-dipping pattern have a worse prognosis compared to dippers [7,8] and nocturnal HTN is usually associated with the absence of physiological drop of nocturnal BP values when compared to daytime ones although it can be found in dippers and (rarely) extreme dippers [9].…”

Current approach to nocturnal hypertension

“…Decreased baroreflex functions can trigger stroke, myocardial infarction, and vascular dementia. Diurnal hormonal changes affecting the autonomic nervous system, such as the sympathetic nervous system, parasympathetic nervous system, insulin, cortisol, and renin angiotensin aldesteron system, lead to circadian blood pressure changes [1].…”

“…Conditions such as increased activity of the renin angiotensin aldesterone system, increased sympathetic nervous system activity, sodium retention, obstructive sleep apnea syndrome, impaired renal function, age, obesity, diabetes, secondary hypertension, heart failure, decreased physical activity, insomnia and work stress cause nocturnal hypertension [1,4].…”

“…If the decrease in blood pressure is >20%, it is mentioned excessive dipping, 11-20% dipping, 1-10% nondipping and 0% inverse pattern. However, an increase in nighttime blood pressure compared to daytime blood pressure is called reverse/rising pattern [1,4]. Dipping pattern is not observed in conditions such as sleep disorder, obstructive sleep apnea, obesity, high salt intake, orthostatic hypotension, autonomic dysfunction, chronic kidney disease, diabetic nephropathy and advanced age [1].…”

“…Nocturnal hypertension is an important risk factor for cardiovascular and cerebrovascular diseases [1]. With the widespread use of ambulatory blood pressure, the diagnosis of nocturnal hypertension has increased [1]. Nocturnal hypertension causes target organ damage.…”