Relationship Between Blood Pressure and Physical and Cognitive Function in the Oldest Old

To the Editor: Sabayan et al.1 demonstrated in a longitudinal study that higher systolic blood pressure (SBP) and pulse pressure (PP) were associated with lower activity of daily living (ADL) disability scores (both P = .01). Similarly, higher SBP, diastolic blood pressure (DBP), and mean arterial pressure (MAP) were associated with higher Mini-Mental State Examination (MMSE) scores (all P < .05). The presence of vascular risk factors such as hypertension, diabetes mellitus (DM), heart disease, and smoking since middle age increase the risk of Alzheimer's disease (AD).2, 3 The relationship between blood pressure (BP) and dementia has been the subject of numerous epidemiological studies, and midlife hypertension is a risk factor for dementia and AD, but the association between BP and risk of dementia is lower in older adults. A previous study examining 2,053 individuals aged 65 and older demonstrated that the prevalence of hypertension was lower in individuals with AD (60.6%) than in those with normal cognitive function (70.5%, P = .005). In multivariate analysis, AD was found to be negatively correlated with hypertension (odds ratio = 0.649, 95% confidence interval = 0.461–0.916).4 The 96 individuals aged 85 and older were examined in a subgroup analysis of this study population. Participants were divided into three groups according to SBP level (Group 1 (110–146 mmHg), n = 55; Group 2 (147–161 mmHg), n = 18; Group 3 (162–215 mmHg), n = 23). Mini-Mental State Examination (MMSE) (P = .87) and Lawton-Brody instrumental activity of daily living (IADL) (P = .26) scores were similar in the three groups. Although the median IADL score in Group 3, the highest blood pressure group, was higher than in the other groups, this finding was not significant. The median ADL score of Group 3, the highest blood pressure group, was significantly better than others (P = .03) (Table 1). These results suggest that higher BP is associated with less physical disability at age 85. Furthermore, higher BP was not related to cognitive decline at age 85 and older. These results are in concordance with the findings of Sabayan and colleagues. Although midlife hypertension is a risk factor for cognitive decline, hypertension in older adults does not have a negative effect on cognitive function. Furthermore, higher BP levels in the oldest old were positively correlated with ADLs. Further longitudinal studies will be necessary to determine new cutoff values for optimal BP in the oldest old. Conflict of Interest: The editor in chief has reviewed the conflict of interest checklist provided by the authors and has determined that the authors have no financial or any other kind of personal conflicts with this paper. Author Contributions: Mehmet Kuyumcu: study design, supervision of data collection, statistical analysis, writing the paper. Yusuf Yesil, Burcu Balam Yavuz, Meltem Halil: study design, statistical analysis, writing the paper. Mustafa Cankurtaran, Servet Arıoğul: study design, supervision of data collection, writing the paper. Sponsor's Role: No sponsor.