Relationship between obesity and resistant hypertension

Resistant hypertension is estimated to affect less then 5% of the general population with hypertension, as one common contributing factor is obesity. We studied the influence of obesity on the prevalence of resistant hypertension (rHTN) among Israeli hypertensive patients. We included patients with primary hypertension from 30 general practice clinics across Israel. For each patient we recorded blood pressure (BP) levels, Body Mass Index (BMI), Lipid and Glucose levels, the presence of other coronary heart disease risk factors, the presence of target organ damage (TOD) and the treatment profile. rHTN was defined as systolic BP above 140 mm Hg or diastolic BP above 90 mm Hg (for diabetics 135 and 85 mm Hg respectively) despite treatment given at maximally recommended doses of at least 3 anti-hypertensive medications. 3828 hypertensive patients were enrolled in the study after giving an informed consent. 352 (9.2%) had rHTN. Mean BMI for the rHTN group was 31.0 ±6.0 as compared to 28.8±4.7 for the control-hypertensive group (p<0.0001). 133 (53.0%) of the rHTN group were obese (BMI>30 kg/m2) compared to 41.4% of the hypertensive group. We found rHTN to be directly related to the BMI status (Table) and that rHTn patients were older (66 Vs. 64.7, p=0.02), were more of the female gender (72.2%, Vs. 57.4%, p<0.0001) had a higher LDL (149±45 Vs. 133±42, p<0.0001) and had more TOD (58.9% Vs. 35.5%, p<0.0001). Logistic regression was performed to determine parameters indicative of rHTN and found BMI, female sex and age to be indicative of rHTN. In conclusion, obesity is a frequent finding among resistant hypertension patients and may play a roll in the development of resistant hypertension.