Pattern of body mass index (BMI) among adult hypertensive attending a general outpatient clinic

Abstract

Background: Obesity and hypertension are becoming increasingly more prevalent in many African and other developing countries, leading to an increase in the burden of chronic non-communicable diseases. Epidemiological studies have attributed this development to nutritional transition as a result of urbanization, adoption of western lifestyles and demographic migration. In recent times Asaba – the capital of Delta State, Nigeria – is witnessing a rapid growth in urbanization and fast food eateries. Several studies have shown that Blood Pressure (BP) is directly associated with Body Mass Index (BMI) in populations worldwide. However, some variations exist in the pattern of the association between BP and BMI among populations. This study was aimed at determining the relationship between BMI and BP in the patients attending the General Outpatient, Clinic of Federal Medical Centre (FMC) Asaba Delta State.
Methods: A cross-sectional study was conducted between November 2013 and February, 2014 in which the body weight, height and BP of 304 study participants attending the GOP clinic were determined using standard protocols. BMI was calculated as weight divided by height squared and high BP was defined using the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure (JNC) VII guidelines. All the statistical analyses were performed separately according to gender using the Statistical Package for Social Sciences (SPSS version 17.0). P values < 0.05 were considered to indicate statistical significance.
Results: The age range of the study sample was 20-65 years. 51.3% of participants were males, while 48.7% were females. The mean weight, height and BMI in the study population was 76.93± 21.77kg, 1.62±0.13m and 22.22±5.83kg/m2. The male subjects were little heavier and taller than the females. The mean SBP and DBP in the sample population were 108.60± SD of 23.96mm Hg and 73.72±SD of 15.17mm Hg respectively. Males had higher SBP and DBP than the female subjects. The prevalence of obesity in the sample population was 9.5%; more males 5.3% were obese than females 4.3%. Less than 12% of the subjects had SBP in the hypertension range. For DBP 20.1% of participants were in the hypertension range. Males had a relatively high prevalence of SBP than females, while females had a relatively higher prevalence of DBP than males. There was a positive relationship between systolic and diastolic BP and BMI. Correlation coefficient showed that relationship of BMI with SBP (r = 0.872, p<0.05) was stronger than DBP (r =0.857, p<0.05)
Conclusion The study demonstrated an association between blood pressure and BMI in the outpatient setting, suggesting that obesity is a strong risk factor for the development of hypertension in males and females.