Introduction:
“Globesity”, defined by the World Health Organisation (WHO) is now a worldwide epidemic that is currently escalating, with approximately 2.3 billion overweight adults and 700million obese individuals (Jiang et al., 2016). Obesity has been linked with an increasing prevalence of diseases such as cardiovascular disease (CVD) and hypertension (HTN).
HTN is the most common, costly and preventable CVD, which in itself predisposes individuals to strokes, acute myocardial infarction, and increased incidence of overall and CVD mortality (Pescatello et al., 2004). Estimations show around 20% of the population have high blood pressure or require medication to control blood pressure (BP). Identifiable factors associated with high BP include, older age, increased BMI, sedentary lifestyle, smoking, poor nutrition, excessive alcohol consumption and genetic predisposition (Ostir et al., 2006).
Current projections estimate that 40% of adults will acquire HTN by 2030 (Pescatello et al., 2015). This escalating prevalence of HTN has led to concerns about cost, effectiveness and potential deleterious side effects of Hypertensive medications, and currently more intensive efforts in habitual interventions such as exercise for the control and prevention of HTN is being pushed to relieve this public health burden (Ghadieh & Saab, 2015).
The client in question processes multiple identifiable risk factors which have led to the pre-hypertensive diagnosis such as, increased age, increased BMI, and a sedentary lifestyle. This assignment will outline an evidence-based exercise programme in order to assist in the reduction and management of the client’s BP and sedentary lifestyle.
Discussion
Obesity ultimately occurs through an imbalance between energy expenditure and energy uptake. Excessive weight amounts through the disproportionate uptake of calories in comparison to calories utilised by the body. Authors argue environmental factors can also contribute to obesity such as socioeconomic status, the region of residence, ethnicity and season (Jiang et al., 2016).
Relationships between obesity and HTN are well established within the adult population; what remains unclear is the mechanism in which obesity ultimately causes HTN (Jiang et al., 2016). Theories include, that over-activation of the sympathetic nervous system (SNS), renin angiotensin system and quantity of intra-abdominal and intra-vascular fat all contribute to the pathogenesis of obesity-related HTN.
HTN accounts for 13.5% of yearly morality, making it the leading chronic factor of death. Prevalence for HTN in women is approximately 65% in women aged 60years or older (Ghadieh & Saab, 2015). Studies show HTN levels are higher in women than men in aging populations (Pescatello et al., 2004).
Pre-hypertensive is classified with a BP of ((systolic blood pressure (SBP)120-139 or diastolic blood pressure (DBP)80-89 mm Hg)), although positive relationships between CVD and BP start with levels as low as 115/75mm Hg (Pescatello et al., 2004). It is well documented that SBP naturally increases throughout adult life, alongside progressive arterial stiffening, whereas DBP plateaus in the sixth decade and decreases thereafter, hence isolated systolic HTN is increasingly common (Pescatello et al., 2004). With each 20 mm Hg decrease in SBP the risk of cardiovascular events half, thus it is recommended that the client in question attempts to reduce SBP by 20 mmHg over the course of their exercise programme.
PA influence and management of HTN
In recent years physical activity (PA) has become the cornerstone in the primary prevention of at least 35 chronic conditions (Booth et al., 2012), with public health strategies such as “exercise as medicine” and now “movement for movement” where the nations’ health in all communities is everyone’s concern (Gates et al., 2017).
The national heart foundation, WHO and the international society of Hypertension among others all encourage increased PA as a first line intervention for the prevention and treatment of pre-hypertensive individuals (Ghadieh & Saab, 2015) rather than pharmacological medications (Cornelissen & Smart, 2012).
Large epidemiological studies show exercise decreases BP levels post exercise, which in turn is attributed to the treatment and prevention of HTN (Pedersen & Saltin, 2015). This post-exercise physiological response is referred to as post-exercise hypotension (PEH). This hypotensive response to exercise is caused by the reduction in norepinephrine levels which inhibits sympathetic activity. Angiotensin II, endothelin levels their receptors and adenosine circulation is also reduced which causes a decrease in PVR and increase baroreflex sensitivity (Ghadieh & Saab, 2015).
Liu et al (2012) noted that PEH can be further utilised as a potential screening tool, to identify whether exercise can be promoted as antihypertensive therapy. Persons who do not see an immediate reduction in BP, may not benefit from exercise prescription (Ex Rx) and thus antihypertensive drug therapy should be implimented (Pescetello et al., 2015).
Whilst Ex Rx is widely advocated in the use of hypertensive and pre-hypertensive individuals, prescriptive components such as Frequency, Intensity, Time, Type (FITT principle) and amount of BP reduction differ between professional bodies, and thus needs further investigation in order to pre-determine the optimal FITT principle for HTN and Pre HTN. Current literature states that individuals with pre -or stage 1 HTN do not require screening prior to Ex Rx given they have no known diseases or other CVD (Ghadieh & Saab, 2015).
Frequency
The frequency in which hypertensive patients should exercise is widely agreed by all professional committees/organisations as daily (Pescetello et al., 2015). BP is lowered on days where individuals exercise due to PEH. PEH is known to immediately reduce BP by 5-7mmHg in patients with HTN after a single bout of exercise, with reductions being sustained for up to 24 hours, thus in order to maintain this BP level exercise should be completed daily (Ghadieh & Saab, 2015). According to the findings of Liu et al (2012) these acute reduced BP responses, also have a strong correlation with long-term reductions in BP levels.
Complimentary reasoning for daily PA is that typically hypertensive individuals are commonly overweight or obese and thus high-frequency exercise is needed in order to achieve a caloric expenditure that exceeds caloric intake (Rigaud & Forette, 2001). If these expenditure levels are not met initial weight loss and successful continuation of that weight loss will not be achieved (Pescetello et al., 2015).
Intensity
Past literature advises that intensity for individuals with HTN should be within the moderate intensity bracket with aerobic exercise between 40% to <60% VO2max or heart rate (HR) reserve (Pescetello et al., 2015); however, recently more randomised control trials and meta-analysis’s have endorsed vigorous aerobic exercise (Eicher et al., 2010). Eicher et al (2010) noted that for each added 10% in VO2max there was further 1.5mmHg decreased in SBP and DBP decreased by 0.6mmHg over the following 24hours. If the client can tolerate higher levels of PA such as running or fast swimming, these findings suggest that vigorous levels of physical exertion will acutely lower BP to a greater extent than that of lower level PA such as walking. Although Eicher et al (2010 proved this in acute responses, there was no evidence to show that increase reductions in BP were sustained long term.
Mixed evidence has been reported for high-intensity interval training (HITT) for the reduction of BP with some investigators arguing that HITT has a superior effect on the reduction of BP levels in individuals with higher resting BP (∼8 mmHg) in comparison with normal BP (∼3 mmHg). However, Holloway et al (2015) noted that HITT elicited negative responses in the skeletal muscles of rats with HTN, whereas moderate aerobic exercise had a positive correlation on both skeletal muscle and cardiac adaptions. It can be concluded that more investigation is needed weighing the benefit-to-risk ratio of this form of exercise on hypertensive humans.
Time
Professional organizations currently recommend hypertensive patients exercise for a minimum of 30minutes daily; with weekly activity totalling a minimum of 150 minutes; this is consistent with the NHS guidelines for healthy adults up to 65 years (Pescetello et al., 2015).
Many studies including that of Guidry et al (2006) now state that the PA recommended daily allowance (RDA) can be broken up throughout the day (fractionised aerobic activity). Hypertensive males were randomly selected into a short (15min) exercise group and a long (30min) exercise group, where both completed light (40 % VO2max) or moderate (60 % VO2max) intensity. Results found that PEH was achieved for the following 24hours no matter the exercise duration (Guidry et al., 2006). Cornelissen & Smart’ (2013) meta-analysis argued that whilst both SBP and DBP levels were reduced after 30-minute low-intensity training, only BP reductions in DBP levels were statistically significant. Given a significant portion of individuals have isolated systolic HTN, this method is arguably irrelevant in this population.
For many individuals time is a major deterrent for the completion of Ex Rx, thus fractionised aerobic exercise (3x10mins) performed at multiple stages throughout the day may be beneficial (Pescetello et al., 2015). The client in question could alter her means of transportation to the maternity ward; leaving the car 15 minutes’ walk away would allow her to attain her 30minute requirement for the day with minimal lifestyle alterations.
Researchers have concluded that PEH is a low threshold phenomenon, in terms of exercise duration; and for individuals that can complete either a single 30-minute bout of exercise or complete a fractionised approach, PEH is a viable method of controlling HTN and pre HTN.
Type
There is broad consensus supporting the use of aerobic exercise for the treatment, prevention and control of HTN due to consistent results showing BP is lowered by 5-7mmHg. Aerobic exercise is commonly the first line of treatment in individuals with stage 1 HTN with no evidence of CVD or coronary risk factors (Ghadieh & Saab, 2015).
Dynamic resistance training (DRT) is becoming common practice in the treatment of HTN with growing evidence DRT modestly reduced BP levels in stage 1 hypertensives, with no evidence to state it creates chronic worsening of BP or acute triggering of cardiovascular events (Ghadieh & Saab, 2015). Lack of consensus among professional organisations for the use of DRT as a sole treatment modality is to be attributed to the current weak evidence-based literature surrounding DRT (Pescetello et al., 2015). These shortfalls in literature likely underestimate the effectiveness of DRT. For the client in question, DRT integration into her Ex Rx would not only reduce BP levels but also promote positive adaptions to attenuate the effects of aging (Ribero et al., 2017). Mota et al (2013) investigated the acute and chronic effects on BP in 32 elderly women with controlled HTN and found DRT reduced SBP/DBP by 14/4 mmHg, warranting the suggestion that moderate intensity DRT may be a viable stand-alone therapy for treating HTN.
DRT should be undertaken on 2 or more days per week in conjunction with aerobic exercise). and should incorporate all major muscle groups (Pedersen & Saltin, 2015). The client could participate in any of the following activities in order to meet these guidelines: machine weights (2x 8-12reps), working with resistance bands, body weighted exercises, yoga, tai chi, and gardening; all of which can be carried out with her husband come retirement.
The client can progress exercises as required however the FITT principle should always be considered. It is not recommended that large increases in any FITT component should be undertaken especially intensity. Medical considerations should also be accounted for such as BP controls and changes in drug therapy. “Well Woman” clinic can offer regular BP testing and other lifestyle alterations (nutritional advice) that can help monitor and compliment the clients Ex Rx.
Conclusion
According to professional guidelines the client should engage in 30 minutes PA daily, this should consist of aerobic activity initially at moderate intensity, with gradual progression to vigorous activity coupled with DRT in order to further reduce BP levels and promote positive physiological adaptions combating the aging process. The client can monitor their intensity over the course of the Ex Rx by perceived exertion utilising the Borg Scale (Pescetello et al., 2015).
Given the patient is responsive and attains PEH it is hoped that the client can reduce BP level from pre-hypertensive (SBP120-139 or DBP80-89 mm Hg) to normotensive over the course of the Ex Rx. Reducing SBP level by 20mm Hg the client will half her risk of CV events and restore normotensive status.
As discussed minimal lifestyle alterations need to be made in order to attain RDA of 30minutes per day and can be fractionised on weekdays if necessary. Completely regular moderate-intensity aerobic exercise and DRT with her husband will help ensure a retirement for both in good health.