https://imcjms.com/public Ibrahim Medical College Journal of Medical Science https://imcjms.com/public/registration/journal_full_text/72 Tue, 02 Aug 2016 12:12:09 +0000 The prevalence of hypertension was reported higher in the coastal areas in different populations of the world. There was no study on the prevalence of hypertension among the coastal people in Bangladesh. This study addressed the prevalence and risk of hypertension among people living in the coastal areas of Bangladesh. Overall, 7058 (m / f = 2631 / 4427) people volunteered to participate in the study. The crude prevalence of sHTN was 17.8% [95% CI, 17.39 – 18.21] and dHTN was 19.0% [95% CI 18.08 – 19.92]. Compared to female, the male participants had higher prevalence of both sHTN (16.4 v. 20.2 %, p<0.001) and dHTN (17.4 v. 21.5%, p<0.001). The prevalence rates of sHTN were 14.6, 18.5 and 24.6% in the poor, the middle and in the rich class, respectively (p<0.001). Similar trend was observed with dHTN. Both types of HTN increased with increasing age (p<0.001), BMI (p<0.001), WHR (p<0.001) and WHtR (p<0.001). Logistic regression analyses proved that the participants of higher social class, of advancing age and with higher obesity had excess risk of hypertension. Positive family history of HTN, DM and stroke had also increased risk for HTN. Introduction   The study protocol was approved by the Ethical Review Committee of the Bangladesh Diabetes Association (BADAS).     Fig.1: Map of Bangladesh showing the location of six coastal districts included in the study.         Blood pressure was taken after 10 min rest with standard cuff, fitted with mercury sphygmomanometer while the participant sitting face to face and talking comfortably with relax mood. A mean of the two measures was accepted. The cut-off values for systolic and diastolic hypertension (sHTN, dHTN) were >135 and >85mmHg, respectively.   The biophysical characteristics (mean with standard deviation) were compared between participants with and without hypertension (both sHTN, dHTN). The Chi-sq test estimated the association of hypertension with age-groups, sex, social class and obesity. Logistic regression estimated the effect of risk factors (sex, age, income, BMI, WHR and WHtR) in different models with different combinations taking sHTN and dHTN as dependent variables. Family history of HTN was also included in the models. The quantitative variables (age, BMI, WHR, WHtR) were transformed into quartiles (Q1, Q2, Q3, Q4) and entered in the regression analyses where the Q1 was taken as a reference category. All statistical tests were considered significant at a level of £5%. SPSS version 20.0 was used. Results Biophysical characteristics were compared between subjects with and without hypertension. Compared with the non-sHTN (SBP: <135 vs. ³135 mmHg) the participants with sHTN had significantly higher age (p<0.001), higher obesity (BMI, WHR, WHtR for all p<0.001) and higher FBG (p<0.001). There was no significant difference for T-chol, TG, HDL and LDL [table 1]. Likewise, compared with the non-dHTN (DBP: <85 vs. ³85 mmHg) the participants with dHTN had significantly higher age and higher obesity though no difference was observed in lipids (table not shown). Table-1: Prevalence (%) of systolic and diastolic hypertension (sHTN, dHTN) of the study population according to sex and social class                  Binary logistic regression analysis quantified the effect of individual risk factor (sex, social class, family-history, age, BMI, WHR, WHtR) on hypertension. The analyses included sHTN and dHTN as dependent variables separately. The risk factors were entered into the equation as the independent variables in different combination of different models (model 1-4). Model 1 included sex, family history of hypertension and social class; Age quartiles were added to model 2; BMI and WHtR quartiles were added to model 3 and 4, respectively. Considering all the models, family history of hypertension, higher social class, advancing age and increasing obesity were found to have excess risk for systolic hypertension. The increasing WHtR was proved to be an important obesity indicator, which profoundly reduced the effect of higher age (model 3 vs. 4); whereas, the increasing BMI, an indicator for general obesity had no such effect on age for developing sHTN. The findings of logistic regression taking sHTN as a dependent variable were found almost similar to dHTN (Table not shown). Discussion The response rate was satisfactory (80.2%). The prevalence of hypertension in the coastal population is higher (19%) than that of rural (16.8%) and urban (11.3%) native Bangladeshis.4,5 It is lower than the Chinese study,2,3 which reported an increasing trend over time. In China, the observed prevalence of hypertension was 9.8% in the 1980s, 18.5% in the 1990s and 30.0% in the 2000s. We have no previous report. Hence, it is not possible to assess the trend in the study population. Yadav et.al observed a higher prevalence of hypertension (32.2%) in India,12 but the study participants were affluent people and older (age ³30y). Another Indian study by Anchala et.al13 that included population from different areas reported prevalence of hypertension similar to this study. The study had some limitations. The determination of accurate age was difficult. Most of the participants did not know their date of birth. The age of the participant was approximated based on some national political and / or historical events like liberation war of Bangladesh and worst disasters faced by the coastal people. We could not also assess the grading of physical activities due to different types of lifestyle and occupational heterogeneity. Furthermore, we had to abandon the history taking on dietary habit – firstly, because of diversity in different communities and secondly, it was a time consuming exercise. Again, it would have been better if we could have estimated the salt content of the local drinking water and the locally produced food products. Conclusions   We are indebted to The Fred Hollows Foundation (FHF) for the financial support. We are grateful to the Principal of Barisal Medical College for making arrangements of temporary laboratory room in his college premises. We acknowledge the help extended by the leaders, the teachers, students and the participants of coastal communities. 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