A Cross sectional descriptive community based study was undertaken during January 2007 to December 2008 in the rural township of Tasgaon, which is 25 kms north-west of Miraj under Sangli district of Western Maharashtra, India. The majority of the population belongs to the lower socio-economic strata. Agriculture and animal husbandry are the major occupations. This area is Rural Health Training Centre under the Department of Community Medicine, Government Medical College, Miraj, India. As per the house to house survey carried out recently, total population of the area divided in four sectors was 35,500 and total population above age 40 yrs was 14352. Inclusion criteria for the study population comprised of the individuals above 40 years of age, residents of Tasgaon area and willing to participate in the study. Systematic random sampling was applied to get the desired sample size from four sectors of Tasgaon area.

Considering assumed average of prevalence of 7% [4–7] (from various previous rural hypertension prevalence studies) and permissible error 0.9%, desirable minimum sample size for present study was estimated to be 3284. However, allowing non response and exclusion criteria as well as considering desirability to have larger sample for better validity of observations, (but also considering the limitations of time frame), sample size of 25 percent of total population above 40 years of age i.e. 3600 persons was considered and covered.

Score      Mental Stress

Up to 40  No Stress

41- 200    Less Stress

Over 200  More Stress

The institutional Ethical committee approved methodology and data collection procedure of the study.

Pre-designed and pre-tested semi-structured proforma containing the requisite items of socio-demographic data and life events to calculate mental stress score was used to collect data from individual households. At first, every effort was made to relax the participant. Participants were explained about the nature of study and assured that the information given by him/ her is required only for study purpose and will be kept totally confidential. Blood pressure was measured thrice in right arm at one minute interval using adult cuff size in sitting position. Finally average of second and third observations was considered and the first measurement was discarded. Hypertension was diagnosed as per JNC VII [8] criteria. Participants detected to be having active and acute complaints related to cardiovascular disorders were referred to the Rural Hospital, Tasgaon for pertinent investigations and further management.

Data was analyzed and appropriate statistical tests (Chi-square, F-test, Z-test) were applied. A value of p < 0.05 was taken as significance level.

‘Mental Stress Score’ was given on the basis of Presumptive Stressful Life Event Score (PSLES) [9]. Standardized and statistically tested this score uses at least 51 stressful life events experienced by otherwise normal Indian population. The mean stress score for 51 life events have been formulated in the scale. All participants were interviewed and the cumulative summing of total life events is calculated as per the scale and the score is presented as follows:

In the present descriptive cross-sectional study of Hypertension in relation with mental stress among the population aged over 40 years in a rural township of Tasgaon (Disrict Sangli, Western Maharashtra, India), 3600 subjects were surveyed. Maximum age recorded was 88 yrs. Mean age was 56 yrs ( ± 9.9 yrs) while Male to female ratio was 1.8: 1. Mean systolic blood pressure was 138mm/Hg (± 10.53 mm/Hg) & diastolic blood pressure was 87mm/Hg (± 6.19 mm/Hg).

[Table/Fig-1] indicates that, overall prevalence of hypertension in study population was 5.92%. Males had maximum cases of hypertension [169(7.27%)], while in females, cases were found to be 44 (3.44%). This difference was found to be significant. (χ2 = 22.99, p < 0.001) The rise in number of cases with increasing age was statistically significant. (χ2 = 133.8, p < 0.0000001).

[Table/Fig-2] shows that, Study subjects belonging to ‘More Stress’ group showed maximum number i.e. 127 (7.68%) cases of hypertension which was statistically significant in our study (p =0.00006). Prevalence of hypertension was minimum i.e. 3.46 % in ‘No stress’ group. When data was analyzed separately for both genders, χ2 test indicated significant association between mental stress and occurrence of hypertension (p < 0.001) in the total study groups as well as in males. However in females, the difference was not statistically significant (p =0.3197).

Mean stress score of the study population was 188. Mean stress score of hypertensive study subjects was much higher i.e. 219 than Normotensive study subjects (157) which was statistically significant (p <0.001). Males had significantly higher stress score in both hypertensive as well as Normotensive group. Z-score showed significant difference between hypertensive and Normotensive subjects [Table/Fig-3].

Two groups i.e. Normotensive and hypertensive were analyzed with mean systolic and diastolic blood pressure with the level of stress. It was observed that, as the stress increases mean systolic blood pressure in both group increases. It was found to be statistically significant by F-test [F-statistics-4.633 (p = 0.010)]. While insignificant changes occur in diastolic blood pressure [F-statistics-1.566 (p = 0.211)]. Systolic as well as Diastolic blood pressure was obviously higher in Hypertensive subjects in all stress groups as shown by Z-score test. Average blood pressure of Hypertensive group was 146/90 mmHg while in Normotensive group it was 130/83 mmHg [Table/Fig-4].

Hypertension is a major health problem in India and in other developing countries. The various Indian studies estimated a prevalence rate of hypertension among rural population ranging from 1.99% to 21.2% [3–5]. The present study consisting study population above 40 years of age showed a prevalence of 5.92% which is comparable with recent studies carried out in various parts on India [10,11].

Age related increase of hypertension was observed in the present study. Maximum number of cases of hypertension was observed in population above 60 years of age [119 (55.8%)]. The rise of blood pressure with age is said to be due to ageing process, atherosclerotic changes in blood vessels, stress, strain and some unknown factors. This shows that blood pressure rises with age probably due to effects of genetically programmed senescence in body system as well as accumulation of environmental influences. These results were comparable to study findings reported by Gupta et al.,[12] and Todkar et al., [13].

A positive association was observed between level of stress and development of hypertension. Persons having higher mental stress (i.e. More stress group) were definitely having maximum number of cases of hypertension [127(59.6%)] whereas ‘No stress’ group showed only 26 cases (12.2%). It is proven fact that stress results in immediate sympathetic stimulation with a vasomotor response that result in high-output state and elevated blood pressure [14]. In a systematic review by John J. and Bhatt D. [15] over ‘Emerging Risk Factors for Atherosclerosis’ observed that five out of 13 studies showed that stress was strongly associated with hypertension. Similar observations were made by Piero Mustacchi [14] wherein he correlated emotional, sociocultural and occupational stress with prevalence of hypertension. So, as the mental stress score increases, prevalence of hypertension goes on increasing.

Influence of gender in hypertension prevalence has been observed among men who showed higher prevalence compared to women in the present study. Such observations were also reported by Prasanth et al [16] in rural residents of Kerala, India. In the present study, men showed higher prevalence of hypertension as the level of stress increases [from 4.17% (No stress) to 9.65% (More stress)], but women had insignificant effect of stress on prevalence of hypertension [from 2.01% (No stress) to 4.10% (More stress)]. Taylor et al., [17] proposed the ‘tend-and-befriend’ female stress response for such difference as compare to ‘fight-or-flight’ response in males. The available literature emphatically shows that, women can adjust to the adverse psychosocial situations and the untoward, unfavorable events in a more composed manner owing to their unique psycho emotional profile; probably this is the factor which protects the women from the infliction of emotional insults consequent upon the mental stress. They are more able to cope up with such a stress by virtue of the parallel release phenomenon inherent to the female gender. This is the only plausible explanation to the observations recorded in relation to mental stress score in the present study.

It was observed that mental stress was more in hypertensive subjects (219 ± 34.34) compared to n ormotensive subjects (157 ± 36.36) as shown by mean mental stress score. Moreover, males had higher stress score than females in both the group. This was found to be statistically significant. This could be attributed to sympathetic activity and baroceptor reactivity to mental stress as described earlier by Claude Julien [18].

Mean systolic and diastolic blood pressure of study population was analyzed in relation with level of stress. It was observed that mean systolic blood pressure was significantly increases as the level of stress increases in both Normotensive [(129 (±9.58) to 130 (±12.33)] as well as hypertensive group [141 ( ±7.49) to 146 ( ± 6.86)] but there was insignificant difference in mean diastolic blood pressure. A cohort study conducted in Canada during 1978-82 by Carol Buck et al.,[19] to study hypertension prognosis and onset of age showed similar results comparable with the present study.

To summarize the discussion, the present study consisting of study population above 40 years of age showed a prevalence of 5.92% while age related increase of hypertension was also observed. As the mental stress score increases, prevalence of hypertension goes on increasing.

In the present descriptive cross sectional study on hypertension for evaluation of mental stress as a risk factor, total 213 cases of Hypertension were detected. Overall prevalence of hypertension was found out to be 5.92 %. It was found that, as the stress increases, risk of hypertension increases. Statistically significant association was found between mental stress and hypertension for males. But in females, no such association was found. Mental stress definitely acts as risk factor for hypertension.