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Common but Underrated - Are we Neglecting these HypertensiveSubsets in India? -
  JOHTN
REVIEW ARTICLE
Common but Underrated - Are we Neglecting these Hypertensive
Subsets in India?
Tiny Nair
Department of Cardiology, PRS Hospital, Trivandrum, Kerala, India
Address for correspondence: Dr. Tiny Nair, Department of Cardiology, PRS Hospital, Trivandrum - 695 002, Kerala, India.
E-mail: tinynair@gmail.com
Received: 21-11-2018; Accepted: 05-12-2018
doi: 10.15713/ins.johtn.0145
 
ABSTRACT
Unusual subsets of hypertension need different strategies for detection, treatment and follow up. Isolated systolic hypertension ofthe young (ISH-Y), metabolic nocturnal hypertension (MNH) and white coat 'Alarm' are subsets which are found in India, butoften go undetected. A detailed review of such unusual subsets.
Keywords: Isolated Systolic hypertension, nocturnal hypertension, white coat hypertension
How to cite this article: Nair T. Common but Underrated - Arewe Neglecting these Hypertensive Subsets in India?. Hypertens2019;5(1): 21-24.
Source of support: Nil
Conflict of interest: None
 
 

Introduction

The detection, awareness, treatment, and control rates ofhypertension are poor in Indian subcontinent; the huge1.3 billion population posing a substantial challenge to healthproviders. The new data analysis in JAMA estimates that asystolic blood pressure (SBP) between 110 and 115 mmHgaccounts for 212 million disability-adjusted life year worldwide;of which, 39 million (around 20%) are from India.[1] The scenarioof hypertension detection management in India is challenging; asper the National Capital Region cross-sectional database, there isa progressive increase in prevalence - from 23% in urban areas and11% rural areas in 1991-1994 period to 42.2% urban and 29.9%rural in 2012-2014. More concerning is the fact that these crosssectionaldata show that there has been no substantial change interms of awareness, treatment, and control rates of hypertensionin the tested population between the two time periods.[2]

The data from Jaipur (Jaipur Heart watch), in contrast, showprogressive rise in awareness (13-56%), treatment (95-36%), andcontrol (2-21%) from 1991 to 1994 compared to 2012-2014 period,despite the point that the numbers fell short of the WHO globalmonitoring framework and UN sustainable development goal.[3]

Why Bother about Subsets?

The availability of an array of drugs has made drug choice confusingamong general practitioners (GPs), the group who tend to see thehypertensives in the first place. Clear demarcation of some of thesehypertensives into distinct subsets would give a distinct advantagein choosing out the target population, defining their outcome, andtreating them with guideline-recommended therapy.

 
This review aims at looking at some of the subsets unique inthe Indian population.

Are they Common?

Despite the fact that epidemiological data are not available, mostGPs and specialists tend to see such patients of hypertension offand on. A clear knowledge about such subset would enable themto better document such subsets making it possible to organize adatabase of such distinct subsets.

Why are these Subsets Unusual?

Several subsets of hypertension are described depending onetiology, pathophysiology, and associated comorbidities.Classification depending on elevation of systolic, diastolic, orboth parameters also helping subclassification. We describethree new subsets of hypertension which are seen in clinicalpractice which need to be defined as subsets since they needdifferent diagnostic criteria, different outcome, as well asdifferent modality of treatment. These subsets are unusual inthat they differ in presentation, outcome, and treatment.

Hypertension Journal, January-March, Vol 5, 2019 21

Nair Subsets of hypertension

Common but Underrated - Are we Neglecting these HypertensiveSubsets in India?

Subset 1

ISH-Y

With increase in age, SBP tends to increase, while diastolic bloodpressure (DBP) tends to decrease.[4]

Common but Underrated - Are we Neglecting these HypertensiveSubsets in India?

(Adapted from JNC 7 and Burt et al., 1995, Hypertension23: 305-313)

Isolated elevation of SBP Isolated systolic hypertension(ISH) is generally seen in elderly population with increasedperipheral resistance and stiff arteries. The diastolic pressure istypically normal or low.

An almost similar blood pressure (BP) reading with isolatedelevation of SBP may be seen in stress prone, young peoplewho are generally anxious and exhibit features of sympatheticoverdrive.

In ISH-Y, the BP elevation is driven entirely by sympatheticoverstimulation. Clinical signs of sympathetic overdrive includesinus tachycardia, tremor, sweating, and features of anxiety[Box 1]. They are generally < 40 years of age, working in highstressjobs (IT sector) and handling time-bound projects withtheir corporate future at stake.

Common but Underrated - Are we Neglecting these HypertensiveSubsets in India?

 
Data from a large French cohort of 19,386 hypertensiveswere classified into three categories; those with heart rate (HR)between 60 and 80, 80 and 100, and >100. There was progressiveincrease in mortality (coronary heart disease, cardiovasculardisease, and all-cause mortality) with increase in HR, proving therelationship between HR and outcome in hypertension.[5]

Julius et al. analyzed the data of 15,193 patients enrolled inthe valsartan antihypertensive long-term use evaluation trial. Itshowed that, even those with well-controlled BP, a faster HRincreases cardiovascular (CV) event rate, compared to thosewith controlled HR, indicating the important and pivotal role ofsympathetic nervous system activity in determining the outcomeof hypertensive patients.[6] The national health service (NHS)guideline also recommends the use of beta-blockers in thissubgroup of patients with ISH and sinus tachycardia, driven byan excess of sympathetic outflow.

Among the array of beta-blockers available in the market,these young patients of ISH-Y tend to have better compliancewith highly selective beta-blockers, in view of the absence of sideeffects such as fatigue, bronchospasm, and erectile dysfunction.This makes cardioselective β-blocker such as bisoprolol andnebivolol as preferred agent for the treatment of ISH-Y.

Subset 2

Metabolic Nocturnal Hypertension (Metabolic Owl)

There are middle-aged patients with a typical clinical pictureof obesity, impaired fasting glucose (IFG)/Frank diabetes,and metabolic syndrome with host of metabolic derangementincluding increase triglycerides and uric acid levels. Theyoften have features of obstructive sleep apnea (OSA). Theirechocardiogram and Echo tend to show evidence of the leftventricular hypertrophy (LVH), but more often, the office BPis not severely elevated. In fact, a dichotomy between officemeasures BP (mismatch) and LVH is given a clue to the diagnosis.Many patients can have classical Class 2 effort angina [Box 2].

Common but Underrated - Are we Neglecting these HypertensiveSubsets in India?

Ambulatory BP in these patients shows a typical pattern of milddaytime hypertension with severely elevated nocturnal BP. Thispattern was previously confused with masked hypertension. Isolatednocturnal hypertension tends to increase total mortality andcardiovascular events for more than isolated daytime hypertension.

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Subsets of hypertension Nair

Common but Underrated - Are we Neglecting these HypertensiveSubsets in India?
Chart 1: Difference between morning blood pressure (BP) and pre-awakeBP in ABPM

Common but Underrated - Are we Neglecting these HypertensiveSubsets in India?
Chart 2: Difference between morning blood pressure (BP) andlowest nocturnal BP

In a review of data on nocturnal hypertension, Li et al.[7]clearly showed that isolated nocturnal hypertension is seen moreoften in Chinese (10.9%) and Japanese (10.5%) population aswell as South African people (10.2%) in comparison to lowerrates among West European population (6%). This mightaccount for the lack of data and clinical importance of nocturnalhypertension in literature and guidelines since majority of dataand guideline emanate out of the western world.

Angina in these patients can result from decreased coronaryblood flow as a result of decreased coronary flow reserve.

An increase in intake of high fructose corn syrup, which isused as a sweetening agent in packaged food and sweetenedbeverages (cola) can exacerbate the metabolic derangement byincreasing uric acid and triglycerides in this subset.

Subset 3

White Coat Alarm

White-coat hypertension (WCH) is a stress response of thepatient resulting in elevation of BP during interaction with amedical personal. In general, this condition is thought to bebenign. An ambulatory BP shows normal BP values as thepatient goes outside the area of medical consultation (hospital).WCH is defined as an office BP >140/90 with 24-h ambulatoryBP average of < 130/80. It is estimated that 15-30% of peoplewith elevated office BP has WCH. It is estimated that, generally,the BP of any patient tends to progressively drop by 15/7 mmHgduring the third office visit compared to the first visit even inthe absence of intervention of lifestyle or pharmacologic agents.Persistently, elevated office BP of > 140/90, measured out ofoffice BP < 130/80, normal ABPM average BP < 130/80, andabsence of target organ damage are thought to be clues to suspectthe diagnosis of WCH.[8]

 
The long-term outcome of WCH is unclear. While moststudies agree that patients of WCH have a higher chance ofprogression to sustained hypertension; and the risk of WCHis more than normotensive patients while less than those withsustained hypertension, the actual natural history is unclear sincestudies have looked into different groups of patients.

The analysis of IDACO database shows that InternationalDatabase on ABPM in relation to CV Outcomes shows thatcompared to normotensives, WCH with low baseline risk hassimilar outcomes, while those with high baseline risk (ISH, age,and diabetes) have a higher CV risk with WCH in comparison tonormotensives.[9]

The subgroup that we find a high risk is the one with WCHwith an early morning rise of BP. Studies have shown that thosewith early morning BP rise have a higher chance of plaquerupture (connected to protein misfolding and the inappropriateactivation of proteasome-ubiquitin pathway). Carefulinterpretation of the ABPM tends to give a clue to the warningsignals of this subset.

In addition to the WCH in the ABPM, a difference of morningBP in comparison to pre-awake BP of more than 25 mmHg ora difference between morning BP and lowest nocturnal BP ofmore than 35 mmHg points to the possible presence of thissubset. Since the BP rise tends to be triggered by sympatheticsystem and the overall nocturnal BP is normal, beta-blockers arelikely to be more effective in this subset. The presence of sinustachycardia also points to this diagnosis.

Conclusion

The three subsets of hypertension discussed above are uniquein nature pertaining to their diagnosis, prognosis, and treatment.Understanding their clinical presentation would help theclinician in targeting their therapy more precisely for a betteroutcome.

References
  1. Forouzanfar MH, Liu P, Roth GA, Ng M, Biryukov S, Marczak L,et al. Global burden of hypertension and systolic blood pressureof at least 110 to 115 mm hg, 1990-2015. JAMA 2017;317:165-82.
  2. Roy A, Praveen PA, Amarchand R, Ramakrishnan L, Gupta R,Kondal D, et al. Changes in hypertension prevalence, awareness,treatment and control rates over 20 years in national capitalregion of India: Results from a repeat cross-sectional study. BMJOpen 2017;7:e015639.

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Nair Subsets of hypertension

  1. Gupta R, Gupta VP, Prakash H, Agrawal A, Sharma KK,Deedwania PC, et al 25-year trends in hypertension prevalence,awareness, treatment, and control in an Indian urban population:Jaipur heart watch. Indian Heart J 2018;70:802-7.
  2. Burt VL, Whelton P, Roccella EJ, Brown C, Cutler JA, Higgins M,et al. Prevalence of hypertension in the US adult population.Results from the third national health and nutrition examinationsurvey, 1988-1991. Hypertension 1995;25:305-13.
  3. Benetos A, Rudnichi A, Thomas F, Safar M, Guize L. Influenceof heart rate on mortality in a French population: Role of age,gender, and blood pressure. Hypertension 1999;33:44-52.
  4. Julius S, Palatini P, Kjeldsen SE, Zanchetti A, Weber MA,McInnes GT, et al. Usefulness of heart rate to predict cardiacevents in treated patients with high-risk systemic hypertension.Am J Cardiol 2012;109:685-92.

 
  1. Li Y, Wang JG. Isolated nocturnal hypertension: A diseasemasked in the dark. Hypertension 2013;61:278-83.
  2. Franklin SS, Thijs L, Hansen TW, O'Brien E, Staessen JA.White-coat hypertension: New insights from recent studies.Hypertension 2013;62:982-7.
  3. Franklin SS, Thijs L, Asayama K, Li Y, Hansen TW, Boggia J,et al. The cardiovascular risk of white-coat hypertension. J AmColl Cardiol 2016;68:2033-43.

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