Relationship Between Depression and Blood Pressure in Community‐Dwelling Oldest‐Old Adults in Japan

Abstract

To the Editor: “Inverse Relationship Between Depressive Symptoms and Arterial Blood Pressure in Community-Dwelling Oldest-Old Brazilians” by Rosset and colleagues1 attracted our attention because of its important point of view about community-dwelling oldest-old adults. Rosset and colleagues1 showed a relationship between low blood pressure (BP) and depression and discussed measures of controlling hypertension in the very old population, but the relationship between cognitive or mental functions and BP in community-dwelling elderly adults has been controversial.2-4 According to the Canadian National Population Health Survey, major depression is a possible risk factor for new-onset high BP.4 On the contrary, a recent study in France indicates that people with low BP have a higher risk of developing depression, whereas those with high BP were not at greater risk for incident depression.3 Moreover, another study in Norway showed that symptoms of anxiety and depression were correlated with lower BP 11 years later.5 Therefore, the findings on the relationship between depression and BP in elderly adults differ across study populations, although these findings are from Western populations, and there are few reports on this relationship in Asian populations. Thus, to address this important issue, a cross-sectional study was conducted to reexamine the relationship between BP and depression in the oldest-old community-dwelling adults in Japan. The total sample comprised 134 elderly people aged 80 and older living in Tosa, Japan (mean age ± standard deviation 84.5 ± 3.9, male:female = 43:91). Data were collected in the annual health examination program that the town held in 2012. They included sociodemographic characteristics, mean systolic and diastolic BP (in two consecutive measurements with the participant in a sitting position), body mass index (BMI), Mini-Mental State Examination (MMSE) score for the assessment of cognitive functioning, 15-item Geriatric Depression Scale (GDS) score, use of antihypertensive and antidepressant medications, and subjective sense of low economic status. The ethical review board of the Graduate School of Medicine, Kyoto University, approved this study. Data were analyzed using SPSS version 20.0 (IBM Inc., Armonk, NY). Mean number of years of education was 8.8 ± 2.0, mean MMSE score was 26.5 ± 3.2, and mean BMI was 22.5 ± 3.2 kg/m2; 67.9% and 4.8% of participants used antihypertensive and antidepressant drugs, respectively. There were no significant associations between GDS score and systolic BP (correlation coefficient (r = 0.017, P = .84) or GDS score and diastolic BP (r = −0.12, P = .17) in simple (Figure 1) or quadratic regression. Moreover, these relationships remained statistically nonsignificant after controlling for age, sex, years of education, MMSE score, BMI, use of antihypertensive and antidepressant medications, and subjective low economic status. Thus, the relationship between depression and BP that was significant in the Brazilian oldest-old population was not detected in a Japanese sample. The expression and management of depression and BP abnormality may differ depending on community, country, and social and medical situation, which may have led to the different results, although hypertension and depression in elderly adults are an important concern in Asian communities. Several reports have stated that the prevalence of hypertension in community-dwelling elderly people in Japan is greater than 70%.6, 7 At the same time, the prevalence of depression in elderly people in three Asian communities was reported to range from 17.2% to 33.8%.8 In conclusion, we should focus on accumulating and comparing results from samples drawn from different cultures and living environments to obtain new perspectives and insights in ethnogerontology. Conflict of Interest: The authors declare no financial or any other kind of personal conflicts with this paper. Author Contributions: HI, KM, KO, TW, RS, YK: study concept, analysis of data, preparation of manuscript. MF, YI, EF, WC, MT: interpretation of data, critical review of manuscript. All authors made substantial intellectual contributions to this manuscript. Sponsor's Role: None.