Medical, Socialogical and environmental issues in cardiovascular disease epidemiology, prevention and rehabilitation.
Diet and High Blood Pressure
Priyanka Rastogi
Department of Dietetics, Monilek Hospital and Research Centre, Jaipur 302004
 
  ABSTRACT
 

The first question that every patient of high blood pressure asks of the healthcare professional or a physician is regarding his diet. Indeed food is a major source of concern to all patients as well as care givers. Food is also a political issue. Very little focus is placed on training of physicians in food and nutrition counseling and the burgeoning food industry has therefore placed its own interests above that of the patients’ health. The hypertension dietary statement from the American Heart Association is a welcome change and shall provide scientific basis to dietary recommendation for a large group of health workers.1.

It has been suggested by the World Health Organisation (WHO) that a diet low in energy-dense foods that are high in saturated fats and sugars, and abundant in fruit and vegetables, together with an active lifestyle are among the key measures to combat chronic disease especially high blood pressure and its vascular complications. This WHO report, commissioned by the WHO and the Food and Agriculture Organization (FAO), from a team of global experts, aims to identify new recommendations for governments on diet and exercise to tackle the ever increasing number of people who die each year from chronic diseases.2 The burden of chronic diseases – which include cardiovascular diseases, cancers, diabetes and obesity – is rapidly increasing worldwide. In 2001, chronic diseases contributed approximately 59% of the 56.5 million total reported deaths in the world and 46%of the global burden of disease. This Expert Report is highly significant because it contains the best currently available scientific evidence on the relationship of diet, nutrition and physical activity to chronic diseases, based on the collective judgment of a group of experts with a global perspective. The Report includes advice on ways of changing daily nutritional intake and increasing energy expenditure by:

  • reducing energy-rich foods high in saturated fat and sugar;
  • cutting the amount of salt in the diet;
  • increasing the amount of fresh fruit and vegetables in the diet.
  • undertaking moderate-intensity physical activity for at least an hour a day.
                Evidence suggests that excessive consumption of energy-rich foods can encourage weight gain, the report says and calls for a limit in the consumption of saturated and trans fats, sugars and salt in the diet, noting they are often found in snacks, processed foods and drinks. The quality of fats and oils in a diet, as well as the amount of salt consumed, the report says, can also have an influence on cardiovascular diseases such as strokes and heart attacks. It is important that these measures are implemented on a large scale in Indian subcontinent where all forms of cardiovascular diseases- hypertension, coronary heart disease and diabetes are rampant.
 
  INTRODUCTION
 
Police job tends to be regarded as inherently stressful because of personnel risk of exposure to confrontations and violence and day to day involvement in a variety of traumatic incidents. As a result high levels of stress related disorders may be prevalent in this population. Increased demands of work impinging upon home life, lack of consultation and communication with the higher authorities in the organization, lack of control over workload, inadequate support have been identified as the potential factors responsible for the stress in the policemen.1, 2

On an average policemen work twelve hours everyday and often put in 36 hours at a stretch during VIP bandobasts and festivals. Unlike other jobs, the policemen start the day with bad news. There is only negative feedback in terms of how many murders, robberies and rapes had taken place the previous night. Working throughout the day in such an atmosphere produces adverse psychological effects. Moreover long working hours, irregular eating habits, sleepless nights, shift duties and disturbed personnel life produces stress in the policemen’s life and they become vulnerable to various disorders.3 To alleviate the stress the policemen tend to stick to the unhealthy habits like drinking liquor or chewing tobacco and suffer from many adverse effects of these habits. Unable to cope up the stressful condition, some of them also commit suicide.

Various studies4,5 have reported significantly high prevalence of stress related disorders like hypertension, diabetes and coronary heart disease among the policemen and found police occupation as a prominent risk factor for coronary heart disease.6 Pyorala et al7 in 22 year follow-up study on Helsinki policemen found coronary heart disease as a major cause of mortality among policemen. Richmond et al8 found high prevalence of unhealthy lifestyle factors like excessive alcohol consumption, tobacco use and no leisure time physical exercises among the policemen. The present study was conducted in order to determine the prevalence of hypertension among the policemen and to study the risk factors associated with hypertension in the policemen.
 
  METHODOLOGY
 
A cross sectional study was conducted on 520 randomly selected constables and head constables from a total of 5256 Maharashtra state police of Nagpur in the year 2003. Sample size of 493 was calculated assuming 15% prevalence of hypertension with worst accepted prevalence of +/-3% at 95% confidence level.

Clinical examinations including the anthropometric examination of the study subjects were carried out. History of present illness, past history, personnel history and family history was obtained using predesigned performa. Blood pressure was measured by mercury sphygmomanometer in sitting position. Systolic blood pressure > 160mm and/ or diastolic blood pressure > 95mm of mercury or subject on anti-hypertensive treatment was regarded as the criteria for diagnosis of hypertension.9 Subjects with body mass index (BMI) 30 kg/m2 were regarded as obese, 25.0–29.9 as overweight and with BMI 18.5–24.9 as normal.10 Leisure time physical activity > 30 minutes a day and for at least 3 days in a week was supposed as the regular physical activity.11 Subjects who have smoked regularly and smoked at least one cigarette on an average each day during previous 30 days were defined as the current smokers.12 Subjects currently consuming alcohol or left this habit within 6 months were considered as alcoholics. Quantitative grading of alcohol consumption was not done.
 
Table 1: Basic characteristics of the study subjects
 
Characteristics Policemen (n=520)
Age (years, mean ± 1SD) 38.57±8.38
Length of police service
> 10 yr
< 10 yr

362 (69.6)
158 (30.4)
Education years
> 10 yr
< 10 yr

428 (82.3)
92 (17.7)
Socioeconomic status
Upper middle
Lower middle

500 (96.2)
20 (3.8)
Tobacco users
Tobacco chewers
Smokers
283 (54.4)
213 (40.9)
70 (13.5)
Alcohol consumption 147 (28.3)
Leisure time physical activity
Yes
No

209 (40.2)
311 (59.8)
Body mass index
Normal
Overweight
Obese

296 (56.9)
189 (36.4)
35 (6.7)
Numbers in parantheses are percent.
 
Data was analyzed on Epi-Info Software 3.2 version. Multivariate logistic regression analysis was performed to determine the predictors of hypertension using yes a = 1, and no = 0 coding to the dichotomous (categorical) variables. Age was fitted as continuous variables and all other variables as categorical variables in the logistic model.
 
Table 2: Basic characteristics of the study subjects
 
Age (years) Subjects Hypertension (%) Unadjusted OR
18-27 30 0 (0.0%)  
28-37 230 34 (13.1) Reference
38-47 168 49 (29.2) 2.74 (1.67-4.47)**
48-58 92 36 (37.0) 3.90 (2.23-7.12)**
Total 520 117 (22.5)  
OR odds ratios with 95% confidence intervals; ** p<0.01
 
  RESULTS
 
Basic characteristics of the policemen are depicted in Table 1. Study subjects being the government employees. They were of 18-58 years of age. Overall prevalence of tobacco use 54.42%. Habit of alcohol consumption was present among 28.27% of the policemen, 36.35% were overweight and 6.73% policemen were obese (overweight and obesity 43.08%). 59.81% subjects were not doing any type of leisure time physical activity.
 
Table 3: Results of multivariate logistic regression analysis for hypertension
 
Term Odds ratio 95% CI Coefficient P value
Age (years) 1.05 1.01, 1.08 0.0461 0.0065
Alcohol consumption (yes/no) 1.65 1.02, 2.66 0.4988 0.0419
Years of education (> 10 vs < 10 yr) 0.84 0.49, 1.46 -0.1689 0.5430
Overweight/obese (yes/no) 1.64 1.05, 2.55 0.4940 0.0291
Physical activity (yes/no) 0.99 0.63, 1.55 -0.0120 0.9580
Length of police service (> 10 vs < 10 yr) 2.17 1.05, 4.52 0.7768 0.0373
Tobacco use (yes/no) 1.77 1.09, 2.87 0.5705 0.0208
Constant     -4.3167 0.0000
CI confidence interval
 
Overall prevalence of hypertension among the policemen was 22.50% as shown in Table 2. In older policemen of 48-58 years of age it was 37.00% with 3.90 times higher risk of hypertension than their younger counterparts. Hypertension was not found in the younger policemen of 18–27 years of age. Multivariate logistic regression analysis was performed to assess the independent impact of different variables on the probability of hypertension adjusted for the influence of other variables. As shown in Table 3, variables like alcohol consumption, tobacco use, overweight /obesity & length of police service (> 10 yrs vs. 10yrs) were found to be potential risk factors exerting significant positive independent impact on prevalence hypertension among the policemen. Policemen of > 10 yrs of police service had 2.17 times higher risk of hypertension than those with 10 yrs of police service even in the absence of other risk factors. Education and leisure time physical activity were found to have no significant independent protection effect against hypertension among the policemen.
 
Table 4: Crude and adjusted odds ratios for hypertension
 
Variables Crude OR (95% CI) P value Adjusted OR (95% CI) P value
Tobacco use (yes/no) 2.54 (1.76, 3.94) 0.0001 1.76 (1.09, 2.86) 0.020
Overweight/obese (yes/no) 1.67 (1.10, 2.55) 0.014 1.63 (1.05, 2.55) 0.020
Alcohol use (yes/no) 2.30 (1.49, 3.55) 0.0001 1.64 (1.01, 2.66) 0.040
Length of police service (>10 vs < 10 yr) 4.49 (2.44, 8.28) 0.0001 2.17 (1.04, 4.51) 0.030
Years of education (> 10 vs <10 yr) 0.41 (0.26, 0.66) 0.0002 0.84 (0.48, 1.45) 0.540
Physical activity (yes/no) 0.96 (0.62, 1.49) 0.86 0.98 (0.63, 1.54) 0.950
OR odds ratio, CI confidence intervals
 
Table 4 shows the comparison between crude and adjusted odds ratios. Variables like tobacco use, overweight / Obesity, alcohol consumption and length of police service retained their significant role as potential risk factors for hypertension among the policemen even after adjustment with other factors, suggesting their independent positive impact on hypertension. Policemen with > 10 years of education were 59% less likely to be hypertensive as compared to those with low level of education (crude odds ratio 0.4, 95%CI 0.25-0.66, p= 0.003). But on adjustment with other variables, education lost its significance as a protective factor (p=0.54). Protective role of physical activity was also not found significant in both crude and logistic models.
 
Table 5: Influence of other factors on odds ratio of length of police service and hypertension
 
Length of police service
(> 10 vs < 10 yr)

Age

Education
(> 10 vs < 10 yr)
Overweight/obese Tobacco use Alcohol use Physical activity
4.49 - - - - - -
2.47 1.05 - - - - -
2.44 1.04 0.70 - - - -
2.46 1.04 0.74 1.64 - - -
2.33 1.04 0.83 1.65 2.06 - -
2.17 1.04 0.84 1.63 1.77 1.64 -
2.17 1.04 0.84 1.63 1.76 1.64 0.98
 
The influence of other factors on risk of hypertension associated with length of police service is shown in Table 5. The odds ratios for hypertension obtained after addition of other factors in the logistic model one by one are depicted in this table from which major confounding factors can be identified. The odds ratio of length of police service (> 10 yrs Vs 10yrs) as shown in column no.1 remained significant and more or less constant when other variables were included (adjusted in the analysis), particularly after age was adjusted. Odds ratio of length of police service was substantially reduced from 4.49 to 2.47 when age was adjusted indicating age as a potential confounding factor for hypertension. Odds ratio marginally changed to 2.46 when education and overweight /obesity were adjusted. However it was reduced to 2.17 when adjusted with the habits of tobacco use and alcohol consumption suggesting higher prevalence and/or a chronic effect of these habits in policemen of > 10 years of service. Finally even after adjustment with all other variables, the risk of hypertension associated with length of police service remained significantly high (OR 2.17, 95%C1 1.04-4.51, P = 0.03)
 
  DISCUSSION
 
The present study revealed 22.5% hypertension prevalence among the policemen of Nagpur, which is higher than that found in many recently conducted studies in India on general urban population on similar age group. These studies13 reported hypertension prevalence of 15.52% in Mumbai, 14.08% in Ludhiana, 10.99% in Jaipur, 11.59% in Delhi and 13.11% in Chandigarh. In Nagpur, Athawale et al4 reported 8.4% prevalence of hypertension among municipal employees.

Younger policemen of 18-27 years of age were found to be free from hypertension as majority of them were newly appointed policemen. They have to pass through various physical (athletic) tests and medical examination and only absolutely fit candidates are appointed as policemen. Prevalence of hypertension was significantly higher in policemen of 48-58 years of age. This suggests that the policemen join the police department in extremely good health with athletic physique but retire with some stress related disorders.

Prevalence of overweight/obesity (43.08%), tobacco use (54.42%) and alcohol consumption (28.27%) was higher in policemen as compared to general employees observed in other studies. Athawale et al4 reported prevalence of overweight/obesity 23%, tobacco use 45.95 and alcohol consumption 25.6% among the general employees of Nagpur Municipal Corporation. As these factors were found to be significantly associated with hypertension, high prevalence of hypertension among policemen can be attributed to high prevalence of these factors among them. Length of police service was significantly and independently associated with the prevalence of hypertension and its association was not entirely mediated by other factors. This indicates that as the duration of police service is increased the risk of hypertension is increased is increased even in the absence of other risk factors except the level of stress which was not studied and hence could not be adjusted. This shows that a policemen’s job may be a stressful job responsible for increased risk of hypertension among the policemen. As the seniority of policemen increases more and more responsibilities are posed on them. Burden of these job responsibilities1 in addition to increased family responsibilities perhaps increases the level of stress resulting in higher risk of hypertension among the policemen of > 10 years of service as compared to their other counterparts.

This study found no significant role of education as an independent protective factor against hypertension in policemen suggesting that the policemen with high as well as low level of education bear equal risk of hypertension. However on crude analysis policemen of > 10 years of education found to have significantly low risk of hypertension as compared as compared to those of < 10 years of education. This may be due to clustering of unhealthy habits like tobacco use and alcohol consumption among those with low level of education as on adjustment with these factors, no significant difference was found in the risk of hypertension between the policemen of high and low level of education. However other studies15 on general population found education as a significant independent protective factor against hypertension. Similarly leisure time physical activity had no significant protective effect against hypertension in the policemen. Protective effect of both education and physical activity was probably neutralized by stressful police job.

Some of the subjects particularly the older policemen were not aware about the cause of death of their parents or other blood relatives. They were not certain whether coronary heart disease or stroke was due to hypertension, diabetes or due to other factors. Hence to avoid the bias, family history of hypertension was not included in the analysis. However, if distribution of family history of hypertension is assumed uniform, possibility of adjusted risk of hypertension associated with length of police service being over or under estimated can be very well ruled out. Dietary habits, level of stress and types of police duties most commonly associated with the stress were also not studied. In spite of these limitations, this study succeeded in finding out potential risk factors prominently associated with the high prevalence of hypertension among the policemen. This study also gives a clue that police job itself may cause stress related disorders in the policemen. However, further studies are needed to identify which types of police duties in the Indian scenario are associated more significantly with the stress or stress related disorders among the policemen.
 
  Acknowledgements
 
We are grateful to the Commissioner of Police, Nagpur, for permitting us to carry out this study on policemen. We are also thankful to the Deputy Commissioner of Police (Headquarters) and other police authorities for their support and cooperation during the course of study.
 
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