Resistant Hypertension and Sleep Apnea among Patients in the Primary-Care Setting

Introduction: This study ascertained the prevalence of Resistant Hypertension (RH) among black patients. It also determined whether patients with RH are at greater risk for Obstructive Sleep Apnea (OSA) than hypertensives.

Method: A total of 200 patients (mean age=63±13 years; female=61%) with a diagnosis of hypertension provided subjective and clinical data. RH was defined using the JNC 7 and European Society guidelines (uncontrolled BP despite treatment with 3 medications [including a diuretic] in suitable combination and recommended dosage). We assessed OSA risk using the Apnea Risk Evaluation System ARES, defining high risk as a total ARES score >=6. Patients provided informed consent under the supervision of the IRB at SUNY Downstate Medical Center. Analysis was performed with SPSS 18.0.

Results: Of the sample, 68% were diagnosed with diabetes, 83% dyslipidemia, 38% heart disease, and 11% stroke; 89% were overweight/obese. Average systolic and diastolic BP were 135±19mmHg and 75±11mmHg, respectively; blood glucose levels averaged 145±64mg/dL, triglycerides 147±85mg/dL, and LDL 97±38mg/dL. Overall, 26% met criteria for RH, and 40% were at high OSA risk. Logistic regression analysis, adjusting for effects of age, gender, and medical comorbidity, showed that patients with RH were nearly 2.5 times more likely to be at high OSA risk, relative to those with hypertension [OR=2.46, 95%CI: 1.03-5.88, p<0.05].

Conclusion: Our findings show that the prevalence of RH among blacks fell within the range of RH for the general hypertensive population (3-29%). However, patients with RH were at significantly greater risk of OSA compared with patients with hypertension.