| Introduction. Essential hypertension (EH) is associated with cognitive deficits, and higher blood pressure levels have been related to lower levels of cognitive function. Executive functions, speed of processing, memory and attention are especially impacted. Hypertension may affect cognitive function because of pathological physiological changes in the brain (e.g., white matter lesions and/or lacunar infarctions) or behavioral/emotional alterations associated with hypertension (e.g., stress, anxiety, and depression). Objectives. (1) Rule out white matter lesions and lacunar infarctions as necessary causes of cognitive deficits in EH; (2) Examine the role of anxiety and depression as a potential mechanism for the relationship between EH and cognitive function; and (3) Determine socio-demographic and medical moderators of this relationship in individuals without structural brain changes. Methods. Ninety five Chinese with EH and 95 age- and education- matched normotensive controls were recruited into the study. All participants had a medical history interview and physical exam, completed Zung's Anxiety and Depression Surveys, and completed the Mini-Mental State Examination (MMSE) and a computerized neuropsychological battery. All participants had an MRI scan of the brain. For the present study, individuals with white matter lesions or lacunar infarctions were excluded from analysis. The remaining sample consisted of 46 hypertensives and 66 controls. Results. Multivariate analyses, controlling for medical/risk factor differences between hypertensive and normotensive groups, revealed no relationship between EH and cognitive function nor EH and emotional status. Two-factor ANOVAs revealed significant EH x Gender interactions for digit discrimination response time (p<0.01) and the MMSE (p<0.05). Conclusions. The present findings suggest that gender moderates the influence of hypertension on cognitive function in the absence of structural brain changes. The adverse neuropsychological sequela associated with hypertension are seen only in female participants. The digit discrimination test, involving cognitive domains of attention, vigilance, and psychomotor speed, and the Mini-Mental State Examination, a test general cognitive ability were significantly affected. Self-reported anxiety was not associated with objective cognitive performance measured by neuropsychological tests and did not account for the relationship between hypertension and cognitive function in females. Future research, especially with female hypertensive patients, is needed to determine the mechanisms associated with cognitive deficits in hypertension. |
