European Journal of Cardiovascular Medicine

A number of patients living with uncontrolled blood pressure remains a challenging problem all over the world.^1,2High blood pressure is one of the most important risk factors for cardiovascular diseases and it has been shown that the reduction of highly or moderately elevated blood pressure levels result in a decrease in stroke and myocardial infarction rates. High blood pressure is ranked as the third most important risk factor for attributable burden on cardiovascular system health status. Hypertension is responsible for 57% of all stroke deaths and 24% of coronary heart disease death in India.³ Therefore it is important to know the prevalence of uncontrolled blood pressure in patients with hypertension.

Number of epidemiological studies have been conducted such as a part of national health and nutrition examination survey such as NHANES 3 in US,⁴Canada,⁵ UK.⁶ In India prevalence of hypertension is about 33% in urban and 25% in rural population. Out of these only 25% of the ruralites and 42% of urbanites were aware of uncontrolled blood pressure. Only 25% rural and 38% of urban Indians are being treated for hypertension. One tenth of rural and one fifth of urban hypertensive population have their blood pressure under control as per this study.⁷

While the prevalence of hypertension declined in many high-income countries from 1975 to 2015, it rose substantially in most low-income and middle-income countries, and especially in South Asia.⁸ In a recent nationally representative study among 1.3 million adults in India, we found that 25% of adults had raised blood pressure (BP), with even young adults aged 18–25 years having a substantial prevalence, at 12%.⁹

Antihypertensive medications are both inexpensive and efficacious.^{10, 11} Yet, only a minority of adults with hypertension in India are diagnosed and receive recommended treatment.¹² This lack of care for people with hypertension, combined with the rapid rise of CVD in India,¹³ requires concerted attention if the Sustainable Development Goal 3 target of reducing premature mortality from NCDs by 30% by 2030 is to be achieved.¹⁴

An alarming rise in HTN projected by Global Burden of Hypertension 2005 study,¹⁵the GBD 2010 study¹⁶ and WHO 2014 NCD India specific data portray a grim picture for the 17.8% of the world’s population who reside in India.

This study is proposed to determine the control of blood pressure in hypertensive patients attending the medical clinics of a tertiary care hospital and to assess the various factors which may be responsible for the uncontrolled blood pressure in these patients.

Aim And Objectives

Aim

To Assess adequacy of blood pressure control in patients with hypertension attending medicine OPD & other medical clinics of hospital.

Objectives

To assess the factors responsible for uncontrolled blood pressure in these patients.

MATERIALS AND METHODOLOGY

STUDY DESIGN:

 Observational prospective study.

STUDY PERIOD: 1 year.

STUDY AREA:

The proposed study was conducted in Department of Medicine, Maulana Azad Medical College and associated Lok Nayak Hospital, New Delhi after clearance from Institutional Ethics Committee.

INCLUSION CRITERIA                       

Patients with essential hypertension, age >18 years.  

EXCLUSION CRITERIA

Pregnancy induced hypertension.

People living with HIV/AIDS.

Patients with known malignancies.

SAMPLE SIZE: A study from a Cardiovascular health program has observed blood pressure control of 59.7%.

Uncontrolled blood pressure = 40.3%.

N=Z_crit²P(1-P) ∕D²

N = Sample size

Z_crit=1.96

P = 0.40

D= 0.1

N=90

Attrition rate = 10% 

Sample size as per above calculation is 99, however for this study we have taken sample size of 100 as per convenience.

METHODOLOGY

All those patients who fulfilled the inclusion criteria were considered in this study after taking consent. Then subjects were evaluated with detailed history, examination with special consideration on the assessment of risk factors and relevant investigations.

MEASUREMENT OF BLOOD PRESSURE (BP)-

BP measurement was done according to the American Heart Association (AHA) recommendation. Blood pressure was repeatedly taken monthly and at the end of 3 months and analysis of the factors for non-compliance was also recorded.

 JNC 8 guideline was used to classify hypertensive subjects.¹⁶

TABLE: - 1 JNC 8 CLASSIFICATION OF BP

Factors for non-compliance viz. Pharmacological compliance and non-pharmacological compliance {activity level, sodium restriction} were taken in account.

To ascertain blood pressure control, we reviewed the documents of patient’s BP recording.

Optimally controlled BP is defined as (according to JNC8 guideline) -

1. An average systolic BP <140 and diastolic BP < 90 mmHg if the patient is younger than 60 years.
2. An average systolic BP< 150 and diastolic BP < 90mmHg if patient is older than 60 years.⁷⁰

RISK FACTORS ASSESSMENT-

Risk factors like, adherence, no of antihypertensive medications, reduced salt intake, knowledge about hypertension, hyperlipidemia, diabetes mellitus, demographic and socioeconomic characteristics, cardiovascular disease, smoking, alcohol physical activity and obesity were assessed in our study.

With scoring scheme of "Yes"= 0 and "No"=1. The items were summed to give a range of score 0 to 4 and was graded as non-adherent (who failed to fulfill anyone of the four criteria in Morisky scale) and adherent. MMAS‑4 is validated in India and other parts of the world in different languages with reliability value.¹⁷

Diabetes mellitus as a risk factor was assessed by taking history, investigation and the medical records provided by the patients. American Diabetes Association (ADA) recommendations were taken into consideration for the diagnosis of diabetes.

TABLE 2:- ADA GUIDELINE FOR DIAGNOSIS OF DIABETES

Cardiovascular Disease (CVD) as a risk factor was assessed by detail history, examination, ECG, echocardiography and old medical documents provided by the patients. It includes ischemic heart disease, coronary artery disease, hypertensive heart disease, cardiomyopathy, pericardial disease like pericarditis and pericardial effusion.

Smoking as a risk factor was assessed by individual history taking and in what form (bidi, cigarettes) the subjects used to smoke.

Evaluation of obesity as a risk factor association, with the Hypertension, was assessed by measuring the height and weight of the patient. From that data Body Mass Index (BMI) was calculated. BMI is defined as a person’s weight in kilograms divided by the square of the person’s height in meters(kg/m²).

TABLE 3:- BMI CATEGORY

Physical activity:

Physically active patients were defined as those who electively exercised for at least 30minutes three times a week.

Socioeconomic status:

Socioeconomic status was assessed by the Kuppuswami Scale, (table no.). Subjects were classified in upper, upper middle, lower middle, upper lower and lower socioeconomic status, based on parameters like education, occupation and family income.

TABLE 4:- KUPPUSWAMI SCALE

Knowledge about control of hypertension:

 The following questions were utilized:-

1. Is hypertension a life-long condition?
2. Is it possible to control it by diet and medications?
3. Mention two or more organs that may be damaged by high BP.

An incorrect answer to any of these questions were indicative of low knowledge. All correct answers given by subjects were indicative of good/adequate knowledge.

Reduced salt intake: Reduce dietary sodium intake (<2.4 g sodium or <6 g sodium chloride) with no added salt intake in the form of pickle, papad, or table salt.

INVESTIGATIONS-

Following investigations were done in the subjects taken part in our study

• Hemogram (Hb, TLC, DLC,)
• Kidney function test - Blood urea and serum creatinine (by spectrophotometry)
• Blood sugar (random blood sugar), Hba1c (by HPLC)
• Lipid profile
• Baseline urine investigations—
• Urine routine and microscopy(RBCs, cast, bacteria)
• 24-hour urinary protein measurement. (HPLC method)
• Urine dipstick method for albuminuria.
• 12 lead ECG (resting stage).
• 2D ECHO wherever indicated.

STATISTICAL ANALYSIS

Data is entered in MS-Excel and analyzed using SPSS (Statistical Package for the Social Sciences) version25.

Quantitative data was expressed in mean and standard deviation.  For paired data paired t test or wilcoxon sign rank test was used.

'p' value <0.05 was considered as statistically significant.

This was an observational prospective study which was conducted in the Department of Internal Medicine, Maulana Azad Medical College and Lok Nayak Hospital, located in New Delhi, India. A total of 100 diagnosed cases with hypertension fulfilling inclusion and exclusion criteria were evaluated in this study. Following observations were made.

SOCIODEMOGRAPHIC PROFILE

GENDER

Out of the 100 patients, 40 were male and 60 were female, (Table: 5). The female to male ratio was 1.5.

TABLE: - 5 : GENDER WISE DISTRIBUTION OF STUDY SUBJECTS (n=100)

In this study, number of female patients in controlled BP group were 36 (60%) and in uncontrolled BP group were 24(40%). Number of male patients in controlled BP group were 33(82.5%) and in uncontrolled group were 7(17.5%); with P value=<0.01.

AGE

In our study, the mean age of patients was 50.48±12.01 years (table: 6). The distribution of the population was maximum in the age group 45 - 70 years. In our study, there were no subjects with age of more than 75 years.

TABLE: -6 AGE WISE DISTRIBUTION OF STUDY SUBJECTS

FIGURE: - 1

RESIDENCY-

Out of the 100 subjects 72% were urban and 28% were rural. The urban and town population were residing predominantly in Delhi and outskirt of Delhi. The rural population was resident from neighboring states like – Uttar Pradesh, Haryana.

In this study, patients living in rural area with controlled BP were 21(75%) and with uncontrolled BP were 7(25%). Patients living in urban area with controlled BP were 47(66.2%) and with uncontrolled BP were 24(33.8%); p value =0.47.

OCCUPATION-

Out of the 100 patients, 61% were unemployed and housewife. Among the subjects, 35 % were unskilled/ skilled worker like a factory worker, wage laborer, a farmer by occupation, 3% were doing clerical work and shop owner and only 1% were in professional or semi-professional fields like a teacher, scholar. (Figure-2)

FIGURE: - 2

In this study, employed patients with controlled BP were 27 (69.2%) and with uncontrolled BP were 12 (30%). Unemployed patients with controlled BP were 42 (68.8%) and with uncontrolled BP were 19 (31.2%) ; with P value=0.96.

EDUCATION-

Out of the 100 patients, 57 patients (57%) completed their primary school, 31 patients (31%) were illiterate, 11 patients (11%) attended middle school, and 1 patient (1%) had completed their high school. In this study, Illiterate Patients with controlled BP were 18(58.1%) and with uncontrolled BP were 13 (42.9%). Literate patients with controlled BP were 51 (73.9) and with uncontrolled BP were 18 (26.1%); with P value =0.11.

SOCIOECONOMIC STATUS-

In this study, 67% of the subject population falls under the lower middle segment of Kuppuswami socioeconomic scale. 9% upper middle, 21% upper lower and 3% lower segment of the scale. Hence the majority of our subject population are from lower middle strata of the Kuppuswami scale. In our study, middle class patients with controlled BP were 58 (76.3%) and with uncontrolled BP were 18(23.3%). Lower class patients with controlled BP were 11(45%) and with uncontrolled BP were 13(54.2%); with P value =<0.01. (Table: 15).

COMORBIDITIES

In our study, 13 patients (13%) had diabetes mellitus, 4 patients (4%) had heart disease (coronary artery disease), 2 patients (2%) had respiratory disease (COPD). This was elicited by history from the subjects, old medical documents, ECGs and echocardiography reports provided by the subjects.

In this study, there were no patients with heart disease in controlled BP group (0.0%) and in uncontrolled BP group were 4 patients (100%).  Patients without heart disease in controlled BP group were 69(71.9%) and in uncontrolled BP group were 27(28.1%); with p value =<0.01.

In this study, Diabetic patients in controlled BP group were 7(53.8%) and in uncontrolled BP group were 6(46.2%). Non-Diabetic patients in controlled BP group were 62(71.2%) and in uncontrolled BP group were 25(28.7%); with p value =0.20.

SMOKING-

Among the study population, 14% used Tobacco in the form of smoking cigarettes and bidi. Exact quantification was not done in our study.

In this study, Smoker patients in controlled BP group were 9(64.3%) and in uncontrolled BP group were 5(35.7%). Non-smoker patients in controlled BP group were 60(69.8%) and in uncontrolled BP group were 26(30.2%); with p value =0.68.

ALCOHOL-

Among the study population, 5% were current alcoholic. Exact quantification was not done in our study.

In this study, Alcoholic patients in controlled BP group were 3(60%) and in uncontrolled BP group were 2(40%). Non-alcoholic patients in controlled BP group were 66(69.4%) and in uncontrolled BP group were 29(30.6%); with p value =0.65. (figure- 3)

FIGURE: -3 COMORBIDITIES, TOBACCO AND ALCOHOL USE IN HYPERTENSIVE SUBJECTS

LIFESTYLE FACTORS:

In our study, 66% patients were on salt restricted diet (<2.4 g sodium or <6 g sodium chloride) and 73% patients were adhering to anti-hypertensive medications. In this study, patients on salt restricted diet in controlled BP group were 61(92.4%) and in uncontrolled BP group were 5(7.6%). Patients on unrestricted salt diet in controlled BP group were 8(23.5%) and in uncontrolled BP group were 26(76.5%); with p value =<0.001.

In this study, adherent patients in controlled BP group were 64(87.7%) and in uncontrolled BP group were 9(12.3%). Non-adherent patients in controlled BP group were 5(18.5%) and in uncontrolled BP group were 22(81.5%); with p value =<0.001.

NUMBER OF ANTIHYPERTENSIVE MEDICATION TAKEN BY SUBJECTS:

In this study, most of patients (n=50) were on dual antihypertensive (like calcium channel blockers and ACE inhibitors), 39 patients (39%) were taking more than two antihypertensives and 11 patients (11%) were taking single antihypertensive medication.

KNOWLEDGE ABOUT HYPERTENSION CONTROL:

In this study, only 60 patients (60%) had good/ adequate knowledge about prevention and control of hypertension. Rest 40 (40%) patients had low knowledge about hypertension control.

In this study, patients with good/adequate knowledge about HTN in controlled BP group were 53(88.3%) and in uncontrolled BP group were 7(11.7%). Patients with low/inadequate knowledge about HTN in controlled BP group were 16(40.0%) and in uncontrolled BP group were 24 (60.0%); with p value =<0.001.

PHYSICAL ACTIVITY:

In our study, only 40 patients (40%) were physically active, which were defined as those who electively exercised for at least 30minutes three times a week. Whereas rest 60 patients (60%) were living sedentary life. (Table: 7)

TABLE:- 7 PHYSICAL ACTIVITY IN HYPERTENSIVE SUBJECTS (n=100)

In this study, physically active patients with controlled BP were 38(95.0%) and with uncontrolled BP were 2(5%). Physically inactive patients with controlled BP were 31(51.7%) and with uncontrolled BP were 29 (48.3%); with p value =<0.01.

BODY MASS INDEX:

In this study, only 52 patients (52%) had BMI within normal range (18.5-24.9), 38 patients (38%) were overweight and rests of 10 patients (10%) were obese.

In this study, normal BMI patients in controlled BP group were 41(78.8%) and in uncontrolled BP group were 11(21.1%). Overweight/obese patients in controlled BP group were 28(58.3%) and in uncontrolled BP group were20(41.7%); with p value =<0.02.

HYPERLIPIDEMIA:                                                                                                                                      

In our study, total cholesterol was elevated in 23 patients (23%) and triglyceride was elevated in 14 patients (14%).

TABLE: -8 LIPID PROFILE IN HYPERTENSIVE SUBJECTS (n=100)

In this study, patients with normal serum cholesterol in controlled BP group were 60(77.9%) and in uncontrolled BP group were 17(22.1%). Patients with elevated serum cholesterol in controlled BP group were 9(39.1%) and in uncontrolled BP group were14(60.9%); with p value =<0.01.

In this study, patients with normal serum triglyceride in controlled BP group were 63(73.3%) and in uncontrolled BP group were 23(26.7%). Patients with elevated serum triglyceride in controlled BP group were 6(42.9%) and in uncontrolled BP group were8(57.1%); with p value =<0.02.

BP CONTROL STATUS:

In our study, among the patients who were compliant to regular antihypertensive medications 69 subjects had adequately controlled BP (SBP<140 mmHg or DBP <90 mmHg) and despite of their regular intake of  antihypertensive medications 31 patients had uncontrolled BP.

CHARACTERSTICS OF PATIENTS BY CONTROLLED AND UNCONTROLLED BP STATUS:

In our study, no significant age difference was observed in controlled and uncontrolled group, mean age in controlled group was 51.42+ SD12.45 year whereas in uncontrolled group 48.39+ SD 10.83 year with p value =0.23.

The mean BMI was significantly higher in patients with uncontrolled BP 26.91±SD 4.05 as compared to patients with adequately controlled BP 25.19±SD 2.99 (p=0.03). (Table: 9)

TABLE: -9: CHARECTERSTICS OF PATIENTS WITH CONTROLLED AND UNCONTROLLED BP STATUS

SOCIODEMOGRAPHIC FACTORS FOR UNCONTROLLED BP:

In this study, higher prevalence of uncontrolled BP in females 77.4% as compared to males 22.6% with p value =0.01 which was statistically significant.

In our study, there were no significant difference in BP control in urban vs. rural (p=0.47), educated vs. uneducated (p=0.19) and employed vs. unemployed (p=0.57). (Table: 10)

TABLE: -10: DEMOGRAPHIC FACTORS AFFECTING BP CONTROL IN HYPERTENSIVE SUBJECTS

OTHER RISK FACTORS FOR UNCONTROLLED HYPERTENSION:

Comorbidities:

In this study, 19% patients were having co-morbid illness, 14% patients had diabetes, 4% patients had coronary heart disease and 2% had respiratory disease.  In this study, there was no significant difference in prevalence of diabetes, 10.1% in controlled group as compared to 19.4% in  uncontrolled group (p=0.20) and prevalence of respiratory disease, 1.4 % in controlled group as compared to 3.2 in  uncontrolled group (p=0.52).

But the prevalence of heart disease (CAD) was significantly higher in uncontrolled BP group 12.9% as compared to controlled BP group 0.0% (p=<0.01).

Mean cholesterol level in controlled group was 137.68±SD38.12 and 184.13±SD 58.80 in uncontrolled group (p=<0.01).

Mean triglycerides level in controlled group was 126.29±SD38.47 and 157.68±SD55.98 in uncontrolled group (p=<0.01). Uncontrolled BP among subjects was significantly associated with higher levels of cholesterol and triglycerides.

Lifestyle factors:

In this study, there was no significant difference in BP control in patients who were smoking cigarette or bidi (p=0.68) and drinking alcohol (P=0.65).

Reduced salt intake was an important risk factor for uncontrolled BP among hypertensive subjects, Prevalence of reduced salt intake was higher 88.4% in controlled BP group as compared to uncontrolled group (p=<0.001).

 Adherence to antihypertensive medication was higher among patients who had  controlled BP 92.8% as compared to those who had uncontrolled BP 29.0%, which was statistically significant (p=<0.001).

Good knowledge about hypertension control among subjects was significantly associated with adequate BP control 76.8%, and poor knowledge about hypertension was associated uncontrolled BP 77.4% (p=<0.001).

Prevalence of physical activity among subjects was significantly higher in controlled BP group as compared to uncontrolled BP (p=<0.01).

The use of dual antihypertensive was seen in 50% of subjects and 39% were on more than two antihypertensives. As compared to controlled group patients, those in uncontrolled group had significantly more patients who were taking >2 antihypertensives (64.5% vs. 27.5%, P<0.01). (Table: 11)

TABLE: - 11 OTHER FACTORS AFFECTING BP CONTROL IN HYPERTENSIVE          SUBJECTS

Control of hypertension under the purview of ongoing treatment and lifestyle modification remains one of the major aims of management of hypertensives. The current study was carried out in the population with hypertension, getting treatment and regularly following-up from the Lok Nayak Hospital.

Demography

Hypertension is a disease of middle age and elderly, but is being encountered among young’s as well.¹⁸ The mean age of the patients in our study was 50.48 (±12.01) years. Age as a factor did not show a significant association with uncontrolled hypertension in our study (51.42 in controlled group vs. 48.39 in uncontrolled group; p value =0.23). Our findings are consistent with various studies who found that age is not a significant factor affecting control of hypertension^19-22 such as Santiago et al study (64.9 vs. 67.3, P= 0.204),¹⁹ Gebremichael et al study (age >65 years: 36.9% vs. 33.8%, P>0.05),²⁰ Basu C et al. (2013) study (P value =0.361),²¹ and Kamran et al. study  (50.2 vs. 50.4, P=0.6)²² where age of patients with controlled and  uncontrolled hypertension was comparable.

In contrast, few studies have reported an association between increasing age and uncontrolled hypertension.^{23, 24} Literatures showed that age is strongly related to systolic blood pressure and isolated systolic hypertension accounts for the majority of cases with uncontrolled BP in individuals greater than 60 years of age.²⁵ However, according to the Joint National Committee eighth meeting (JNC8) guideline, the systolic threshold for controlled hypertension is 150 mm Hg which is higher than the threshold for uncontrolled blood pressure (140 mm Hg) which could contribute to the high prevalence of uncontrolled hypertension in older age groups.²⁶

Gender

 In our study, there were 60% females and 40% male patients. Female gender showed a significant association with control of hypertension in our study. As compared to patients with controlled BP group, those in uncontrolled BP group had significantly more females (77.4% vs. 52.2) and significantly less males (22.6% vs. 47.8%) (P=0.01). Our findings are in contrast to the findings of other studies. Kamran et al. found that there were significantly more males in uncontrolled group than controlled group (31.1% vs. 21.9%, P=0.001).²² Sandoval et al. also found that uncontrolled BP was significantly associated with male sex (OR: 1.73 [95% CI 1.35-2.22]) rather than female sex.²⁸

Apart from that, results by Asgedom et al, (where 53.8% of the participants were males) showed that there was no association between gender and control of hypertension.²⁴ Even the study by Gebremichael et al. (P=0.593), ²⁰ and Jafar et al. (32.7% males in controlled group vs. 28.8% males in uncontrolled group; P = 0.079),²⁹ supported this finding that gender was not a risk factor for uncontrolled hypertension.

Residence

Living in an urban area has been reported to be associated with an increased risk of hypertension but in our study, there was no difference in blood pressure control between patients living in urban and rural settings, patients living in rural area with controlled BP were 21(75%) and with uncontrolled BP were 7(25%). Patients living in urban area with controlled BP were 47(66.2%) and with uncontrolled BP were 24(33.8%); p value =0.47. This is consistent with previous reports in Africa.^31-32

Horsa et al., Adeniyi et al. and Sarfo FS et al. also supported these findings as type of residence showed no association with control of hypertension (P>0.05).^33-34 In contrast, Daştan İ et al., reported that HT prevalence was higher in rural areas (28.4%) than in urban areas (23.9%), and urbanization was found to be a contributing factor to Hypertension in multivariate regression analysis.³⁵ Residence is an important parameter since poor control of blood pressure among individuals might be linked with the rural poorly resourced residence of the participants.³⁰

Occupation

Occupational stress resulting from a combination of high work demands and low job decision latitude is linked with causation of hypertension in the modern society.³⁶ In our study, out of the total patients, 61% were unemployed/housewife and 39% were employed. Occupation, as a factor did not show a significant association with uncontrolled hypertension in our study, employed patients with controlled BP were 27 (69.2%) and with uncontrolled BP were 12 (30%). Unemployed patients with controlled BP were 42 (68.8%) and with uncontrolled BP were 19(31.2%); with P value=0.96.

Our findings were in line with the study by Asgedom et al. (97.2% patients were employed), ²⁴ Gebremichael et al.²⁰ and Jafar et al., (25.4% patients in controlled group were working and 23.9% in uncontrolled group were working, P=0.473);²⁹ who observed that employment status was not associated with uncontrolled hypertension (P>0.05).

In contrast, few studies have reported an association between increasing type of occupation and uncontrolled hypertension.^{30, 37} This may be due to more the enrolment of more professionals and skilled workers where job strain die to workplace psychosocial factors may contribute to high blood pressure.

Education

Educational status is reported to be inversely associated with blood pressure and risk of hypertension.³⁸ In the index study, among the total patients, 69% were educated and 57% had completed their primary school. Education as a factor did not show a significant association with uncontrolled hypertension in our study. Illiterate Patients with controlled BP were 18(58.1%) and with uncontrolled BP were 13 (42.9%). Literate patients with controlled BP were 51 (73.9) and with uncontrolled BP were 18 (26.1%); with P value =0.11. Our findings were in line with the study by Asgedom et al. (51.2% educated), who also found no association of education with control of hypertension (P>0.05).²⁴

In contrast, one of the studies have reported an association between education and uncontrolled hypertension It was noticed that greater education was associated with better control in BP; because greater education was associated with greater awareness, and treatment; however it was restricted only to older population and was not applicable to younger population.³⁸

Socio-economic status

Low socioeconomic status (SES) is associated with high blood pressure and its related cardiovascular disease morbidity and mortality.³⁹ In the index study, 67% of the patients belonged to lower middle class. Socioeconomic status as a factor showed a significant association with control of hypertension in our study, middle class patients with controlled BP were 58 (76.3%) and with uncontrolled BP were 18(23.3%). Lower class patients with controlled BP were 11(45%) and with uncontrolled BP were 13 (54.2%); with P value =<0.01.

Our findings were in line with the study by Sandoval et al., as uncontrolled BP was significantly associated with low family income (OR: 1.83 [95% CI 1.44 - 2.32]).²⁸Antignac M Et al, also reported that the proportion of uncontrolled hypertension progressively increased with decreasing level of patient individual wealth (P for trend, <0.01).⁴⁰

In contrast, Cha HS et al., found that income level was not significantly associated with hypertension treatment or control. A possible explanation for these findings was that hypertension care is related to adherence rather than to material resources alone.³⁹

It can be said that Socio-economic status plays an important role among the factors that explain inequalities in hypertension awareness, treatment, and thus affects the BP control among patients.³⁹

Comorbidities

In our study, 13% patients had diabetes mellitus, 4% had heart disease, and 2% had respiratory disease (COPD). It was seen that 12.9% of the patients with uncontrolled BP had heart disease while it was absent in any of the patients with controlled hypertension (P<0.01). So, heart as a factor showed a significant association with uncontrolled hypertension in our study. The distribution of other co-morbidities such as DM and COPD was statistically similar in both the groups with controlled and uncontrolled hypertension (p>0.05)

Our findings were in line with the study by Abdu O et al.⁴² who found that presence of comorbidity had a significant association with uncontrolled hypertension. Gebremichael et al. found the presence of co-morbidities in 31.6% cases of uncontrolled HTN which was significantly higher than 18.8% with controlled HTN (P=0.008),²⁰ Even Yang et al, showed that diabetic and kidney disease comorbidities were significantly associated with uncontrolled hypertension.⁴¹ In another of the studies by Asgedom et al., Diabetes mellitus was the most commonly encountered comorbidity associated with uncontrolled hypertension (uncontrolled vs. controlled, 59% vs. 41%, P=0.05).²⁴

It can be said that chronic diseases such as diabetes mellitus, heart diseases, respiratory diseases and chronic kidney disease are associated with hypertension and controlling hypertension among hypertensive patients with these chronic comorbidities might be a challenging problem requiring continuous monitoring and lifestyle changes.²⁴

Tobacco and alcohol use

In present study, 14% patients used tobacco in the form of smoking; and 5% of the subjects were alcoholic. Tobacco and alcohol use as a factor did not show a significant association with control of hypertension in our study. As compared to patients with controlled HTN, those with uncontrolled HTN had comparable patients using tobacco (13.0% vs 16.1%) and alcohol (4.3% vs. 6.5%) (P>0.05). Our findings were in line with the study by Jafar et al., who found no association between smoking and uncontrolled hypertension (controlled group had 6.9% smokers and uncontrolled group had 6.5% smokers, P=0.734).²⁹

In contrast, Gebremichael et al., found that nonadherence to alcohol abstinence was significantly associated with uncontrolled hypertension (10.3% in controlled group and 22.5% in uncontrolled group, P= 0.023).²⁰ The differences may be due to the different amounts of alcohol consumption among the different study groups.

Alcohol is one of the risk factors and is accountable for significant population burden of hypertension. Non-adherence of hypertensive patients to recommendations of alcohol intake makes more difficult to control hypertension.

Recent epidemiological and clinical studies have demonstrated that chronic ethanol consumption (more than three drinks per day, 30 g ethanol) is associated with an increased incidence of hypertension and an increased risk of cardiovascular diseases.^43-49 The magnitude of the increase in blood pressure in heavy drinkers averages about 5 to 10 mmHg, with systolic increases nearly always greater than diastolic increases.⁴⁹ In the Framingham cohort,^54-55  there was an increase of 7 mmHg in mean arterial pressure when heavy alcohol users were compared with all others. A study concluded that blood pressure is higher among active smokers.⁵⁶

Physical activity

In present study, 40% patients were physically active, which were defined as those who electively exercised for at least 30minutes three times a week. Physical activity as a factor showed a significant association with control of hypertension in our study, physically active patients with controlled BP were 38(95.0%) and with uncontrolled BP were 2(5%). Physically inactive patients with controlled BP were 31(51.7%) and with uncontrolled BP were 29 (48.3%); with p value =<0.01. Our findings were in line with the study by Asgedom et al., who also found that physical inactivity (p<0.001) was significantly associated with uncontrolled blood pressure (physically active patients in uncontrolled versus controlled, 84.2% vs. 15.8%, P <0.001).²⁴ Gebremichael et al. also found that nonadherence to physical activity was associated with uncontrolled hypertension (17.8% in controlled group and 32.8% in uncontrolled group were non-adherent to physical activity, P=0.028).²⁰ This is in accordance with another study done in China which showed that lack of physical activity was statistically associated with uncontrolled hypertension.⁴¹

Physical exercise may prevent increases in BP through beneficial alterations in insulin sensitivity, and autonomic nervous system function and vasoconstriction regulation. It also decreases high blood pressure by decreasing body weight and increasing renal function.²⁰

Acutely, exercise has been associated with immediate significant reductions in systolic blood pressure. Combined aerobic and resistance training for as little as one day/week for each mode of exercise are sufficient to reduce BP among healthy elderly women.^57-58 Thus the American College of Sports Medicine recommended aerobic exercise supplemented with resistance training as a means to prevent hypertension.⁵⁹

BMI

Higher BMI (overweight and obesity) is one of the major contributing factor for hypertension; BMI and blood pressure have a direct and apparent relationship.²⁰

We observed that 52% of the patients had BMI within normal range (18.5-24.9), 38% were overweight, and 10% were obese. In the study, BMI(kg/m²) as a factor showed a significant association with uncontrolled hypertension, normal BMI patients in controlled BP group were 41(78.8%) and in uncontrolled BP group were 11(21.1%). Overweight/obese patients in controlled BP group were 28(58.3%) and in uncontrolled BP group were 20(41.7%); with p value =<0.02. Our findings were in line with the study by Gebremichael et al. (BMI 25–29.9 in controlled versus uncontrolled group, 5.6% vs. 20%);²⁰ Jafar et al. (25.24 vs. 24.71, P=0.02829 and others^60-61 who reported that BMI was associated with uncontrolled hypertension thus accounting overweight and obesity as independent predictors of uncontrolled hypertension.

Lipid profile, salt restriction and number of antihypertensives

 In the current study. Total cholesterol and triglycerides were elevated in 23% and 14% subjects, respectively. Mean cholesterol level (184.13 vs. 137.68, P≤0.01) and mean triglycerides level [157.68 (±55.98) vs 126.29 (±38.47), P≤0.01] was significantly higher in uncontrolled group than controlled group. Therefore, lipid profile as a factor showed a significant association with uncontrolled hypertension in our study.

An excessive daily intake of cholesterol and saturated fats, as well as subsequent lipid abnormalities leading to dyslipidemia (hypertriglyceridemia and hypercholesterolemia), is associated with obesity and, consequently, hypertension.⁶²

Studies have shown a direct association of deranged lipid profile with hypertensives as compared to controls;^63-66 and thus higher cholesterol levels among uncontrolled hypertensives may be a simultaneous etiology deranging the blood pressure which needs to be taken care of through diet and physical exercise signifying a vicious cycle of the various parameters affecting the hypertension.

In the index study, 66% patients were on salt restricted diet. As compared to controlled group patients, those in uncontrolled group had significantly less patients with reduced salt intake (16.1% vs. 88.4%, P<0.001). So, salt restricted diet showed a significant association with control of hypertension in our study.

In the present study, 50% of subjects were on dual antihypertensive and 39% were on more than two antihypertensives. As compared to controlled group patients, those in uncontrolled group had significantly more patients who were taking >2 antihypertensives (64.5% vs. 27.5%, P<0.01). Thus, number of antihypertensive medications taken by patients daily also showed a significant association with control of hypertension in our study.

Similar findings were reported by Asgedom et al., who mentioned that the majority, 68.53%, of the participants were taking more than one antihypertensive medication; and 55.9% patients were adding salt to food. Patients adding salt to food were significantly more in uncontrolled group than controlled group (85% vs 15%). The authors found that adding salt to food (P<0.001) was significantly associated with uncontrolled blood pressure (P<0.001) but number of medications showed no significant association with control of HTN (61.7% vs. 38.3%, P=0.23).²⁴

Knowledge about HTN

We found that 60% of the subjects had good knowledge about prevention and control of hypertension. In uncontrolled group, there were significantly more patients who had no knowledge about HTN (77.4% vs. 23.2%, P<0.001). Therefore, lack of knowledge about hypertension showed significant association with uncontrolled hypertension in our study.

It was also noted that the patient population with uncontrolled HTN was not aware about the target blood pressure on treatment, that antihypertensives are to be taken for life and that control of both systolic and diastolic blood pressure is important.⁶⁸ A similar study conducted in a primary care setting in United States⁶⁹ and in tertiary center in Pakistan also concluded the same results.⁷⁰ Gebremichael et al., also found that knowledge about hypertension in hypertensive patients was not adequate overall and was slightly more poor in patients with uncontrolled hypertension.²⁰ Thus it becomes important to make the patients aware about the target values and the role of taking full course of medications with lifestyle changes to have a better blood pressure control.

Adherence to anti-hypertensives

In the index study, 73% of the patients were adherent to antihypertensive medications. As compared to patients with controlled HTN, those with uncontrolled HTN had significantly less patients who were adherent to antihypertensive drugs (29.0% vs. 92.8%, P<0.001). So, adherence to antihypertensive medications showed a significant association with control of hypertension in our study.

Our findings were in line with Gebremichael et al., who found that nonadherence to antihypertensive medication was an independent predictor of uncontrolled hypertension (controlled versus uncontrolled, 38.4% vs. 35.6%, P=0.041).²⁰ Jafar et al., also reported similar findings as high adherence level for antihypertensive medications was significantly more in controlled group than uncontrolled group (37.3% vs. 31.3%, P <0.001).²⁹ Among the other studies, Elperin DT et al., Goverwa et al. and Sarfo FS et al., showed that good adherence to antihypertensive medication is protective to uncontrolled hypertension.^34,66

The present study compares parameters such salt restriction diet and adherence to antihypertensive medications in uncontrolled and controlled hypertension patients in India, which provides valuable information for researchers and authorities, who are responsible for the planning of health services. There are a limited number of researches on BP control status of hypertensive in India. So, this study will provide information about risk factors responsible for uncontrolled blood pressure in patients with hypertension. Our findings have significant public health implications that emphasize the urgency of increased awareness about blood pressure control.

LIMITATIONS

• The sample size was small for the detection of risk factors that has a profound impact on outcomes.
• There might be recall bias and social desirability bias since the behavioral practice of the study participants were based on self-reports and performance of these behaviors was not observed and could not be confirmed.

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