Orthostatic hypertension as a risk factor for age-related macular degeneration: Evidence from the Irish longitudinal study on ageing.

PURPOSE: Age related macular degeneration (AMD) is a leading cause of irreversible visual loss in developed countries. It is associated with vascular risk factors including hypertension. Dysregulated blood pressure (BP) behaviour including orthostatic hypertension (OHTN), hypotension (OH) and BP variability (BPV) are associated with end-organ damage, particularly in the brain. We investigated if abnormal orthostatic BP (OBP) was a risk factor for AMD, for which a vascular aetiology is implicated. METHODS: A nationally representative, cross-sectional study was carried out 2009/2010 in The Irish Longitudinal Study on Ageing (TILDA). Beat-to-beat BP data, measured by digital photoplethysmography during active stand, was used to characterise OBP behaviour in the 30-110 s after standing. OH, OHTN, BPV and normal stabilisation recovery phenotypes were defined. AMD was identified following masked grading of 45° monoscopic colour retinal photographs, which were centred on the macula and taken with a NIDEK AFC-210 non-mydriatic auto-fundus camera. The relationship between OBP recovery phenotypes and AMD in 3750 adults aged ≥50 years was investigated using multivariate logistic regression models, adjusted for traditional AMD risk factors. RESULTS: From 30 to 110 s post active stand, systolic and diastolic OHTN was associated with increased odds of AMD after adjustment for demographics, health behaviours including smoking, family history of AMD, self-report (SR) diabetes, SR cataracts, objective hypertension and prescribed antihypertensives. No evidence of heterogeneity of OHTN effect was found between those who were hypertensive to those who were normotensive. CONCLUSIONS: This study provides evidence that OHTN may be an independent cardiovascular risk factor for AMD.

Explaining significant differences in subjective and objective measures of cardiovascular health: evidence for the socioeconomic gradient in a population-based study.

BACKGROUND: To assess prevalence rates of subjective and objective reports of two cardiovascular disorders (hypertension and hypercholesterolemia) for the same subset of respondents in a large-scale study. To determine whether and the extent to which the socioeconomic health gradient differed in the subjective and objective reports of the two cardiovascular disorders. METHODS: Data from the first wave (2009/2011) of The Irish Longitudinal Study on Ageing were used (n = 4,179). This is a nationally representative study of community-dwelling adults aged 50+ residing in Ireland. Subjective measures were derived from self-reports of doctor-diagnosed hypertension and high cholesterol. Objective measure of hypertension was defined as: systolic blood pressure ≥140 mm Hg and/or diastolic blood pressure ≥90 mm Hg and/or on antihypertensive medication. Objective measure of hypercholesterolemia was defined as: total cholesterol ≥5.2 mmol/L and/or on cholesterol-lowering medication. Objective measures of low-density-lipoprotein cholesterol and high-density-lipoprotein cholesterol were also used. Two measures of socioeconomic gradient were employed: education and wealth. Binary and multinomial logistic and linear regression analyses were used. Analyses were adjusted for an extensive battery of covariates, including demographics and measures of physical/behavioural health and health care utilization. RESULTS: Prevalence of cardiovascular disorders: prevalence of hypertension and hypercholesterolemia was significantly higher when the cardiovascular disorders were measured objectively as compared to self-reports (64% and 72.1% versus 37% and 41.1%, respectively). Socioeconomic gradient in hypertension: the odds of being objectively hypertensive were significantly lower for individuals with tertiary/higher education (OR, 0.74; 95% CI, 0.60-0.92) and in the highest tertile of the wealth distribution (OR, 0.77; 95% CI, 0.62-0.95). In contrast, the associations between socioeconomic status and self-reported hypertension were not statistically significant. Socioeconomic gradient in hypercholesterolemia: wealthier individuals had higher odds of self-reporting elevated cholesterol (OR, 1.28; 95% CI, 1.03-1.58). Associations between socioeconomic status and objectively measured hypercholesterolemia and low-density-lipoprotein cholesterol were not significant. Higher education and, to a lesser extent, greater wealth were associated with higher levels of high-density-lipoprotein cholesterol. CONCLUSIONS: Clear discrepancies in prevalence rates and gradients by socioeconomic status were found between subjective and objective reports of both disorders. This emphasizes the importance of objective measures when collecting population data.

Actimeter-derived sleep and wake data and nocturnal ambulatory blood pressure estimation in subjects with stroke and transient ischaemic attack.

BACKGROUND/AIMS: Abnormalities in nocturnal blood pressure control identified using ambulatory blood pressure monitoring are associated with adverse cardiovascular outcomes. Sleep and wake episodes during such studies are usually identified by means of sleep diaries but these may be inaccurate in stroke patients. We performed a study to determine whether sleep-wake data obtained using wrist-mounted actimeters would significantly influence the results of routinely performed nocturnal ambulatory blood pressure monitoring when compared with diary-based sleep-wake recording and fixed time-period data. METHODS: Actimetry was performed using a wrist-mounted device during routine ambulatory blood pressure monitoring in subjects who had suffered a transient ischaemic attack or stroke. The mean nocturnal blood pressure readings were calculated using sleep data derived from actimetry and diaries and compared for a fixed time period from 11:00 pm to 8:00 am. RESULTS: Twenty subjects (mean age 68 years, and 13 female) were studied. Patients were found to have slept for a median of six-hours (one- to eight-hours) by diary and five-hours (zero- to eight-hours) by actimeter data. Diary and actimeter data agreed in 69% of recordings. The mean sleeping systolic blood pressure was lower when calculated by actimeter data than by diary data (119·6 mmHg vs. 123·2 mmHg, P=0·049, paired t-test) but there was no significant difference in diastolic blood pressure. The mean nocturnal blood pressure calculated from 11:00 pm to 7:00 am was higher than sleeping blood pressure calculated from diary data. (mean systolic blood pressure: 127·6 mmHg vs. 123·6 mmHg, P=0·065; mean diastolic blood pressure 69·0 vs. 64·0, P=0·028). CONCLUSION: Calculation of nocturnal and sleeping blood pressure is lower in subjects with stroke and transient ischaemic attack when objective actimeter-derived sleep/wake data are used.