European Journal of Cardiovascular Medicine

Hypertension is grouped into two main categories. These include primary and secondary hypertension. Primary hypertension is also known as essential hypertension and it affects ninety-five percent of persons suffering from the disease. [1] Causes of hypertension are not yet known, however, factors as age, high salt intake, low potassium diet, sedentary  lifestyle, stress as well as genes have been found as contributing to hypertension. [2] High blood pressure occurring as a  result to a consequence of another disorder or a side effect of medication is referred to as secondary high blood pressure.  Such disorders may include renal failure or renovascular disease. This type of blood pressure is evident in about five to 10% of cases. [3]

Diagnosis of high blood pressure is usually measured with a device called sphygmomanometer. This consist of an inflatable rubber cuff, an air pump and a column of mercury or a digital readout reflecting pressure in an air column as well as  electronic blood pressure machines. [4] The readings are widely expressed in millimeters of mercury or mmHg. Diagnosis of high blood pressure is not based on a single reading except when it is extremely high (above 170-180/105-110). [5] The cause of hypertension is not yet known unless it is unless is secondary high blood pressure. However, there are many underlying factors associated with the occurrence. These factors include: aging, excessive salt intake, sedentary lifestyle as well as genetic factors. A study has showed the presence of 8 high blood pressure mostly amongst adults aged 20-79.  Age is unavoidable. age increases with time. [6]

Aging as a biological process with a decline in the performance of most organs. Less activity as a result to ageing also causes high blood pressure. Impaired ability of the arteries to expand when blood is pumped can be attributed to hardening of the structural changes in the arteries. Hormonal changes as a result to ageing can as well cause high blood pressure.  Changes as decrease in estrogen production, underactive thyroid and overactive thyroid can as well influence the rise in the blood pressure. It is known that high blood pressure usually develops in elderly women after menopause due to hormonal changes. [7]

Aerobic exercises, such as running, swimming, and dance, involve prolonged activity of large muscle groups. In many studies aerobic exercise is defined by physical exercise implying a regular, structured, leisure-time pursuit. [12] Although  aerobic exercise may be demanding and exhausting, individuals have stated that they feel good after completing the exercise. [13] Aerobic exercise is a complex psychobiological stimulus, meaning that repeated exposure to uncontrollable stressors causes the body to eventually become resistant to stress, but with exposure to controllable stress this can be achieved more quickly. Aerobic exercise is considered a controllable stressor that challenges homeostasis by stimulating the sympathetic nervous system to release adrenaline and noradrenaline. [14] 

Design: It is a prospective, cross-sectional and descriptive study.

Place: This study was conducted in the Department of Physiology, Tertiary Care Teaching Hospital over a period of 1 year.

Experimental study design was carried out with a sample of 180 participants. Participants were randomly allocated using sealed envelope method to receive either aerobic training. Informed consent was taken from all the participants included in the study.

Subjects

The sample size was including 60 subjects each.

Inclusion criteria-

• Either gender with age group of 30-60 years of hypertensive subjects according to JNC VIII (Systolic BP >140mmHG and Diastolic BP >90 mmHg) was included.
• The inclusive subjects should be non-alcoholic, non-smokers.

Exclusion criteria-

• Patient with secondary hypertension,
• Left ventricular hypertrophy,
• Recent myocardial infarction,
• Three or more risk factors of CVD,
• Unstable hypertension,
• Mentally unstable or uncooperative patients.
• Patients with history of liver disease, kidney disease and Diabetes were excluded.

Intervention

Hypertension subjects treated with aerobic exercise.

Methods:

One hundred and eighty subjects clinically diagnosed as stage-1 Hypertension were selected According to inclusion and exclusion criteria consisting of 60 subject each. All groups were explained about the purpose of the study. Informed Consent was obtained from the subjects. A brief explanation about the treatment session was explained to Aerobic exercise.

STATISTICAL PROCEDURE

The data collected from the three groups on selected physiological variables were statistically analyzed to determine the significant difference, if any, applying analysis of covariance (ANACOVA).

ALL subjects were divided at random and assigned into three groups of Sixty each. The group mean gains recorded by the various groups during the experimental period of 12 weeks in the criterion measures were tested for significance by applying “t” test. No attempt was made to equate the groups in any manner. Hence, to make adjustments for difference in the initial means the analysis of co- variance was used.

Whenever the ‘F’ ratio was found to be significant for adjusted post-test means, scheffe’s post hoc test was used to determine which of the paired mean difference was significant.

A total of 60 patients who fulfilled the selection criteria during the study were enrolled. The data were analysed, and the final observations were tabulated as below.

Table 1: Distribution of Gender

In table 1, of the 60 samples, 31 were males and 29 females, which correspond to 51.6% of males

Table 2: Distribution of the number of subjects according to age group

In table 2, in this study, the maximum number of patients were in the age group of 51-60 years which were 43.3% (n =26) of total followed by age group 41–50 years having 35.0% (n = 21) followed by age group 30-40 years with 21.6% (n=13) in Group A.

Table 3: Mean Pulse Rate (beats/minute) of aerobic exercise Group

S: Statistically Significant.

It is observed from Table 3 that, aerobic group pre-test Mean Pulse Rate of 79.43 ± 4.73 beats/min (Mean±SD) remain 78.24 ± 4.43 in post-test.

Table 4: Mean SBP (mmHg) of Aerobic exercise Group

S: Statistically Significant.

It is observed from Table 4 that, in aerobic group Mean Systolic Blood Pressure in pre-test 135.65 ± 6.35 mm of Hg and post-test 133.65 ± 6.12.

Table 5: Mean DBP (mmHg) of Aerobic exercise Group

It is observed from Table 5 that, in aerobic group Mean Diastolic Blood Pressure in pre-test 91.63 ± 5.83 mm of Hg and post-test 87.73 ± 5.33.

Table 6: Mean Peripheral vascular resistance (mmHg/min/mL) of Aerobic exercise Group

It is observed from Table 6 that, in aerobic  group Mean Peripheral vascular resistance in pre-test 14431.63 ± 154.83 mmHg/min/mL and post-test 14002.54 ± 143.82 mmHg/min/mL.

The purpose of this study was to compare the effectiveness of aerobics among Hypertension patients. The comparison demonstrated that exercise program among Hypertension patients with 12 weeks duration of aerobic and Resistance exercises were efficacious. In this study General Blood pressure apparatus was used as the primary outcome measure to find out the self efficacy among Hypertension patient as used in a previously published study by Rahman MS, et al (2009). [15]

In our study, aerobic group pre-test Mean Pulse Rate of 79.43 ± 4.73 beats/min (Mean±SD) remain 78.24 ± 4.43 in post-test. Efficacy of exercise in Hypertension was found in similar result done by Rahman MS, et al (2009). [17] Many of the studies have proved that aerobics and Resistance exercises are effective in Hypertension but none of the studies has compared the effectiveness of both. Hence efforts were made in this study to compare both the treatment. A 12 weeks duration of treatment was given in both experimental and aerobic  groups and there was equal improvement in both the groups.

This may be due to the fact that aerobic endurance training decreases blood pressure through a reduction in systemic vascular resistance in which the sympathetic nervous system and the renin–angiotensin system appear to be involved, and favourably affects cardiovascular risk factors by Rahman MS, et al (2009). [18] One theory proposes that exercise enhances shear stress (a force acting parallel to blood vessels) stimulating the production of nitric oxide (NO) by the endothelium.

In healthy blood vessels NO enhance smooth muscle relaxation and maintains the blood vessel in the normal resting state. Small changes in vessel diameter profoundly impacts vascular resistance. There are also vascular structural changes such as increased length, cross sectional area, and/or diameter of existing arteries and veins in addition to new vessel growth Endurance trained subjects, for example, have larger arterial lumen diameter in conduit arteries than untrained controls.

In aerobic group Mean Systolic Blood Pressure in pre-test 135.65 ± 6.35 mm of Hg and post-test 133.65 ± 6.12. In aerobic group Mean Diastolic Blood Pressure in pre-test 91.63 ± 5.83 mm of Hg and post-test 87.73 ± 5.33. Similarly Aerobic based training also appears to increase large artery compliance. [20] Studies suggest that the operating point of the arterial baroreflex is set to a lower BP after an acute bout of exercise. The change in blood pressure cannot be attributed to pure static training. In all but one study, most exercises were dynamic and, therefore, involved movements of the arms, legs or trunk, or both. Furthermore, the training intensity was not always high and ranged from 30 to 60% of one repetition maximum in half of the study groups and from 70 to 80% of one repetition maximum in the others H Robert, et al: (2007). [21]

In aerobic  group Mean Peripheral vascular resistance in pre-test 14431.63 ± 154.83 mmHg/min/mL and post-test 14002.54 ± 143.82 mmHg/min/mL. According to a study done by Cardos supported our study. Although there are fewer data on resistance training, the data suggest that resistance training of moderate intensity is able to reduce blood pressure. Various approaches have been used to increase physical activity and maintain adherence. The effectiveness of these methods has been reviewed by Kahn et al (2002). [23]

According to a study done by C.G. Cardoso, et al; (2010) hypotension was usually observed during waking periods, According to results of resisted exercise, the real importance regarding the role of resistance training in lowering blood pressure is whether it does so in individuals with high blood pressure. [24] It is generally believed that aerobic exercise training lowers resting blood pressure more in patients with moderate-to-severe hypertension, compared with individuals with mild hypertension.

The pre test and post test scored are noted and analysis was done using independent‘t’ test which favored the alternate hypothesis. The intra group analysis was done results were analysis using paired‘t’ test, which favored the alternate hypothesis. The study concludes that aerobic and resistance exercises is achieving normal blood pressure level in patients with stage I hyper tension. Thus, this study accepts the alternate hypothesis.

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