Current Status and Characteristics of Hypertension Control in Community Resident Elderly Korean People: Data from a Korean Longitudinal Study on Health and Aging (KLoSHa Study)

97 Hypertens Res Vol.31 (2008) No.1 p.97-105 Original Article Current Status and Characteristics of Hypertension Control in Community Resident Elderly Korean People: Data from a Korean Longitudinal Study on Health and Aging (KLoSHa Study) Kwang-Il KIM1),2), Hyuk-Jae CHANG1),2), Young-Seok CHO1),2), Tae-Jin YOUN1),2), Woo-Young CHUNG1),2), In-Ho CHAE1),2), Dong-Ju CHOI1),2), and Cheol-Ho KIM1),2) Hypertension is a common disease that greatly impacts the health of the elderly. However, the status of blood pressure (BP) control in the elderly Korean population has not yet been investigated. Subjects aged 65 years or older livings in Seongnam city, a suburb of Seoul, Korea, were included in this study. All subjects were evaluated by a physician, and medication was reviewed by a nurse. Seated BPs were measured by a trained nurse using standard methods. A total of 995 subjects were included in the current analysis (mean age: 76.3 ± 8.7 years). The prevalence of hypertension was 68.7% in the study population, and this value increased with age, peaked in the 75–84 age group, and decreased thereafter. Only 66.1% of hypertensive patients had taken any antihypertensive medication, among which calcium channel blockers (64.2%) were most commonly used. Among the patients on antihypertensive medication, 46% were on combination drug therapy. BP was controlled in 38.5% of hypertensive patients, with systolic BP less controlled than diastolic BP, especially in the oldest-old population. The BP control rate was lower in high-risk patients of diabetes and renal disease. In conclusion, in community resident elderly populations, the BP control rate remains unsatisfactory, especially in high-risk patients. The benefit and optimal level of BP control in oldestold population must be investigated because a lot of elderly hypertensive patients are currently being managed without definite evidence of related benefits. (Hypertens Res 2008; 31: 97–105) Key Words: hypertension, epidemiology, cardiovascular disease, elderly Introduction As more people live to advanced ages, it is important to understand the individual diseases that are prevalent and have great impacts on the health statuses of elderly subjects. Hypertension, one of the most common diseases in the eld- erly, is an important but modifiable risk factor for cardiovascular and cerebrovascular diseases, which are the leading causes of death in most developed countries (1). Preventive strategies toward earlier detection of elevated blood pressure (BP) and its control are likely to offer the greatest promise for reducing hypertension-related morbidity and mortality. Nevertheless, hypertension control rates are From the 1)Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea; and 2)Seoul National University Bundang Hospital, Seongnam, Republic of Korea. This work was supported by an Independent Research Grant (IRG) from Pfizer Global Pharmaceuticals (Grant No. 06-05-039) and by a Grant for the Developing Seongnam Health Promotion Program for the Elderly from the Seongnam City Government in the Republic of Korea (grant No. 80020050211). Address for Reprints: Cheol-Ho Kim, M.D., Ph.D., Department of Internal Medicine, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul 110–744, Republic of Korea. E-mail: Received June 19, 2007; Accepted in revised form August 13, 2007. 98 Hypertens Res Vol. 31, No. 1 (2008) 100% 39.9 44.5 47.7 54.2 75% 69.4 63.3 76.4 69.5 10.1 5.0 50% 12.0 13.3 16.7 12.0 13.0 10.2 25% 25.0 23.9 16.9 22.7 11.7 6.8 6.6 7.7 0% Age Normal Prehypertension Stage I hypertension Stage II hypertension Hypetension with medication Fig. 1. The prevalence of prehypertension and hypertension (stages I, II, and hypertension with medication) by age group in the study subjects. Blood pressure was classified according to JNC 7 reports for each age group. unacceptably low in the elderly population, and the prevalence of hypertension-related cardiovascular disease remains high. These issues might be associated with concern regarding the hazardous effects of BP control. It has been reported that drug treatment may be less effective or even harmful in patients with hypertension aged 80 years or older (2, 3). Furthermore, isolated systolic hypertension, a typical characteristic of elderly hypertension, has been considered not a treatment target but rather a physiologic change related to aging. However, more data are now available to support the indication and intensity of antihypertensive medication in the elderly population. Major randomized, controlled trials clearly showed that active treatment was associated with a significant reduction in stroke rates, major cardiovascular disease, and mortality in elderly people (4–7). However, oldest-old subjects were not included in most of the clinical trials that evaluated the efficacy and safety of antihypertensive medications. Therefore, very little evidence has been reported that supports the benefits of treating hypertension in this subgroup of the elderly population. Recent clinical trials clearly showed the benefits of strict BP control in certain high-risk patients. The risks of hypertension-related morbidity and mortality increase as patients age. Moreover, cardiovascular risk factors such as diabetes, insulin resistance, dyslipidemia, and obesity are frequently associated with hypertension in elderly patients. Therefore, the elderly are considered a high-risk popula- tion. Actually, in a previous clinical trial, the absolute rate of events was much higher in elderly people than in younger people, yet the antihypertensive treatment was very effective in reducing cardiovascular events. This means that the absolute risk reduction per mmHg of BP decrease was higher among elderly hypertensive patients (8). However, it is not clear that strict BP control is beneficial in elderly populations, especially the oldest-old population (9). While there are a lot of uncertainties in managing hypertension in the elderly, the number of elderly hypertensive patients that require treatment is expected to increase because of the aging of the population. As a result, epidemiologic knowledge regarding the characteristics and statuses of elderly hypertensive patients is needed in order to determine the optimal management. The Republic of Korea is the home of the most rapidly aging population in the world. With the increase of the elderly population, especially the oldest-old population, special consideration regarding medical treatment for elderly people must be emphasized. Considering the prevalence of hypertension, optimal treatment of elderly hypertension will become an important medical issue. However, no community-based epidemiologic study has yet been conducted to evaluate hypertension treatments, control rates, and usage of antihypertensive medications in hypertensive elderly Korean patients. T (...truncated)