Visit-to-Visit Blood Pressure Variability in Young Adulthood and Hippocampal Volume and Integrity at Middle Age

Abstract

The aims of this study are to assess the relationships of visit-to-visit blood pressure (BP) variability in young adulthood to hippocampal volume and integrity at middle age. We used data over eight examinations spanning 25 years collected in the Coronary Artery Risk Development in Young Adults (CARDIA) Study of black and white adults (age 18–30 years) started in 1985–1986. Visit-to-visit BP variability was defined as by standard deviation (SDBP) and average real variability (ARVBP, defined as the absolute differences of BP between successive BP measurements). Hippocampal tissue volume standardized by intracranial volume (%) and integrity assessed by fractional anisotropy (FA) were measured by 3-Tesla MRI at the Year 25 examination (n=545, mean age 51 years; 54% women; and 34% African Americans). Mean systolic BP (SBP)/diastolic BP (DBP) levels were 110/69 mmHg at Year 0 (baseline), 117/73 mmHg at Year 25, and ARVSBP and SDSBP were 7.7 and 7.9 mmHg, respectively. In multivariable-adjusted linear models, higher ARVSBP was associated with lower hippocampal volume (unstandardized regression coefficient [standard error] with 1 SD higher ARVSBP: −0.006 [0.003]), and higher SDSBP with lower hippocampal FA (−0.02 [0.01]; all P<0.05), independent of cumulative exposure to SBP during follow-up. Conversely, cumulative exposure to SBP and DBP was not associated with hippocampal volume. There was no interaction by sex or race between ARVSBP or SDSBP with hippocampal volume or integrity. In conclusion, visit-to-visit BP variability during young adulthood may be useful in assessing the potential risk for reductions in hippocampal volume and integrity in midlife.

Higher Blood Pressure is Associated with Greater White Matter Lesions and Brain Atrophy: A Systematic Review with Meta-Analysis

“…Fifty-two studies ( n = 343,794, weighted mean age (MWA) = 58.7 years, women = 53.2%) met the inclusion criteria presented in Supplementary Information; Table S2 . They included 33 cross-sectional [ 5 , 6 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 ] and 26 longitudinal studies [ 5 , 28 , 39 , 41 , 45 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 ] with follow-up ranging from ~2 [ 39 , ...…”

“…Fifty-two studies reported on the peripheral BP measurement and one study additionally reported on non-invasive CPP measurement [ 60 ]. Typically, studies reported BP as a continuous measure (87.7%), but a small proportion (12.3%) reported a categorical measure (normotension vs. hypertension) [ 23 , 25 , 28 , 32 , 38 , 46 , 54 , 69 ] Several methods were used to assess BP including occasional BP (78.8%), 24-h ambulatory BP monitoring (ABP, 11.5%) [ 21 , 39 , 56 , 61 , 66 , 67 ], BP variability over different visits (9.6%) [ 26 , 57 , 62 , 63 ], BP during exercise (2%) [ 58 ], BP reactivity in response to stress (2%) [ 34 ], and inter-arm differences in SBP (2%) [ 27 ].…”

“…Of the 52 studies included, 32 studies investigated the association between BP and WMLs volume, with all of them reporting a positive association ( n = 17,472, MWA = 57.8 years, women = 55.1%, hypertension = 35.4%). Seventeen cross-sectional [ 4 , 19 , 22 , 24 , 28 , 30 , 35 , 36 , 37 , 38 , 40 , 41 , 42 , 44 , 45 , 46 ] and 15 longitudinal studies [ 4 , 19 , 38 , 40 , 44 , 49 , 52 , 53 , 54 , 55 , 59 , 60 , 62 , 66 ] found that higher BP (SBP, n = 48%; DBP, n = 31.2%; PP, n = 8.3%; MAP, n = 12.5%) was associated with larger WMLs. The relationship reached significance in 20 (62.5%) studies (82.6% of participants; 55% longitudinal) ( Figure 4 ) [ 4 , 19 , 24 , 28 , 35 , 36 , 37 , 38 , 40 , 42 , 44 , 46 , 51 , 52 , 53 , 55 , 59 ...…”

“…Of the 23 studies, 21 (91.3%) studies (67.8%of participants) found a negative association between BP and TBV ( n = 15,368, MWA = 57.1 years, women = 55.8%, hypertension = 26.5%). Nine cross-sectional [ 5 , 22 , 25 , 27 , 28 , 32 , 38 , 41 , 47 ] and 12 longitudinal studies [ 5 , 28 , 41 , 48 , 49 , 54 , 55 , 58 , 60 , 62 , 66 , 67 ] found that higher BP (SBP, n = 50%; DBP, n = 28%; MAP, n = 6.2%; PP, n = 15.6%) was associated with smaller TBV. The relationship reached significance in seven (33.3%) studies (26.9% of participants; 71.4% longitudinal studies) ( Figure 4 ) [ 27 , 38 , 54 , 55 , 58 , 62 , 67 ].…”

The association between blood pressure variability (BPV) with dementia and cognitive function: a systematic review and meta-analysis protocol

“…A line of research in neurology and cardiology suggests that the intra-individual variability across successive blood pressure readings may be important to neurological outcomes of incident and recurrent stroke or transient ischemic attack [ 11 – 14 ]. However, the magnitude of association between such blood pressure fluctuation, known as blood pressure variability (BPV), and other neurological outcomes remains less clear [ 15 – 17 ]. Though incompletely understood, high BPV potentially leads to carotid artery denervation and endothelial damage reducing perfusion in microvascular vessels [ 18 ].…”