It was estimated that almost 1/3rd of BP related deaths occurred in normotensive individuals with blood pressure SBP : 120 – 139 DBP : 80 – 89Stamler J, Neaton JD et al. Arch. Of internal medicine, 1993 ; 153 : 598 – 615. Blood pressure, systolic and diastolic and cardiovascular risks : USpopulation data.
The Joint national committee VII report on prevention,detection, evaluation and treatment of high bloodpressure. Chobanian AV, Black HR et al.2003
JNC VII Classification of blood pressureBP SBP, mm DBP, mm Lifestyle Without CompellingClassification Hg Hg modifications IndicationsNormal <120 And <80 Encourage Or No antihypertensivePre hypertension 120-139 Yes 80-89 drug indicated Thiazide-type diuretics for most.Stage 1 Or 140-159 Yes May consider ACEI,Hypertension 90-99 ARB, BB, CCB, or combination Two-drug combination for most†Stage 2 > 160 Or >100 Yes (usually thiazide-typeHypertension diuretic and ACEI or ARB or BB or CCB)
Indeed blood pressure is a continuum and any increase above normal value confers additional independent risk of coronary heart disease, stroke, CHF, end stage renal disease, peripheral vascular disease. (McMahon S, Peto R et al.2002) 3 mm Hg in SBP - 8% in stroke mortality - 5% in CAD mortality (National High blood pressure education programme working group report, 1993.)
The lifetime risk of developing hypertension isestimated to be 90% at the age of 55 years (VasanRS et al.2002, JAMA)Each increment of 20mmHg (SBP) and 10mmHg(DBP) doubles the risk of CVD across the entire BPrange from 11575 to 185115 mmHg
What causes hypertension? Essential hypertension
Probable mechanisms :• Rennin - angiotensin system• Peripheral resistance vessels• Overactivation of sympathetic nervous system
Management of hypertension: Pharmacological Nonpharmacological Why not pharmacological exclusively? Failure of hypertension control point towards : • non-compliance with treatment • long term usage of drug • increased risk of cardiovascular events • economic-constraint
Fasting No energy input ensures negative energy balance Weight loss is rapid but this is disadvantage Disadvantage is a large portion of weight loss is from lean body mass. Nutrient deficit occur ketogenic
Surgery Alteration of gastrointestinal tract capacity Advantage-Caloric restriction is less necessary Disadvantage-risks of surgery
Exercise Evidence supports that level of regular physical activity is more effective than dieting for long term weight control. (French, S.A., et al. 1994) Increased caloric expenditure through aerobic type exercise is a significant option for unbalancing the energy equation to bring out both weight loss and a favorable modification in body composition. (Ballor, and Kessey et al.1994)
Calorie expenditure > Calorie intake by 10% Net 3500 kcal energy burning gives 0.45 kg body fat loss. A meta analysis by staessen et al. showed that mean SBP & DBP reductions were 1.6/1.1 mmHg per kg of body weight by aerobic program. 18 month weight loss program associated with 77% reduction in incidence of hypertension. (He J, Whelton PK et al.2000) The exact mechanism by which weight reduction lowers blood pressure is not known.
Probable mechanism: - Decreased concentration of renin and aldosterone . (Engel S, Sharma AM et al. 2001) - Decrease in activity of sympathetic nervous system. (Esler M, Lambert G et al.2006)
Physical activityEndurance Resistance Isometrictraining training program
Endurance trainingReduces blood pressure through: -Reduction in systemic vascular resistance -decrease in renin - angiotensin activity
A meta analysis of RCTSystolic Blood Pressure 4.7 mm Hg 104 study groups involvedDiastolic Blood Pressure 3.1 mm Hg Intervention Duration – 4 weeksSystemic Vascular 7.1% Endurance Training programResistancePlasma noradrenaline 29%Plasma rennin 20%Body Weight 1.2 kgWaist Circumference 2.8 cm% Body Fat 1.4%HDL 0.032 mmol/l Fagard RH et al, 2006, Sept.
A meta analysis of 54 RCTs showed net reduction of 3.8 mm Hg (SBP) and 2.6 mm Hg (DBP) in hypertensive individuals performing aerobic exercise. (Whelton SP, Chin A et al, 2002)Recommended exercise protocol : – Frequency :- > 3 sessions/week – Intensity :- > 70% VO2 max More than these – Type :- aerobic exercise values have no – Time :- > 45 mins added benefits Halbert JA, Silagy CA et al, 1997
Resistance Training Strength exercise can even be used for lowering blood pressure. The actual blood pressure response depends on : • isometric component • exercise intensity • Muscle mass activated • number of repetitions • duration of contraction • involvement of valsalva maneuver Bjarnason – Wehrens B, Mayer – Berger W et al, 2004
However, a need exists for additional well designed studies on this topic before a recommendation can be made regarding the efficacy of resistance exercise as a non pharmacologic therapy for reducing the resting blood pressure in hypertensive individuals. Kelley G et al, 1997
Isometric Exercise Isometric exercise such as weight lifting can have a pressor effect and therefore should be avoided. Thus it is strictly contraindicated. (Krousel Wood MA, Muntner P et al, 2004)
Moderation in alcohol consumption Effects of alcohol reduction on BP showed a dose dependent decline in BP X in X, He J et al. 2001 Clinical Studies show that BP falls 4 to 5 mm Hg in days or weeks with abstinence from alcohol The JNC VII recommends that alcohol intake should be no more than – 2 drinks/day (male) – 1 drink/day (female)
Dietary ModificationReduce Salt Intake Approximately 6 gm/day can prevent hypertension (trials of hypertension prevention collaborative research group, 1997) Salt Intake reduction 6 gm/day. 7.11 mm Hg (SBP) & 3.88 mm Hg (DBP) in hypertensives. Mac Gregor GA et al, 2002
Reduce Stroke Deaths by 14% and Coronary deaths by 9% in hypertension. Consume foods low in salt (SRD) Avoid pickles, processed foods, chips and chutneys.
Increase potassium intake High potassium intake – reduce blood pressure Consume foods such as fruits, vegetables and especially coconut.
Stress and Anxiety Control Meditation was in one study to reduce SBP and DBP by 10.7 mm Hg and 6.4 mm Hg over a period of 3 months Schneider RH Alexander CN et al, 1995 Progressive muscle relaxation lower SBP by 4.7 mm Hg and DBP by 3.3mm Hg. Yoga is also widely believed to reduce blood pressure Damodaran A, Patil N, Suryavanshi et al, 2002 However, these interventions are with limited and uncertain efficacy. Therefore more trials are needed to confirm its effect.
conclusion Hypertension is a silent killer. Cardiopulmonary Physiotherapy is an integral part of health service. Evidence supports that exercise is the cornerstone for hypertension control, then why it is not being utilized. This is the time, physiotherapist must emerge and show their potential to beat paramount disorder like hypertension where even pharmacological management fails.