Hypertension in the elderly

Epigenetic regulation of L-type voltage-gated Ca2+ channels in mesenteric arteries of aging hypertensive rats

Accumulating evidence has shown that epigenetic regulation is involved in hypertension and aging. L-type voltage-gated Ca²⁺ channels (LTCCs), the dominant channels in vascular myocytes, greatly contribute to arteriole contraction and blood pressure (BP) control. We investigated the dynamic changes and epigenetic regulation of LTCC in the mesenteric arteries of aging hypertensive rats. LTCC function was evaluated by using microvascular rings and whole-cell patch-clamp in the mesenteric arteries of male Wistar-Kyoto rats and spontaneously hypertensive rats at established hypertension (3 month old) and an aging stage (16 month old), respectively. The expression of the LTCC α1C subunit was determined in the rat mesenteric microcirculation. The expression of miR-328, which targets α1C mRNA, and the DNA methylation status at the promoter region of the α1C gene (CACNA1C) were also determined. In vitro experiments were performed to assess α1C expression after transfection of the miR-328 mimic into cultured vascular smooth muscle cells (VSMCs). The results showed that hypertension superimposed with aging aggravated BP and vascular remodeling. Both LTCC function and expression were significantly increased in hypertensive arteries and downregulated with aging. miR-328 expression was inhibited in hypertension, but increased with aging. There was no significant difference in the mean DNA methylation of CACNA1C among groups, whereas methylation was enhanced in the hypertensive group at specific sites on a CpG island located upstream of the gene promoter. Overexpression of miR-328 inhibited the α1C level of cultured VSMCs within 48 h. The results of the present study indicate that the dysfunction of LTCCs may exert an epigenetic influence at both pre- and post-transcriptional levels during hypertension pathogenesis and aging progression. miR-328 negatively regulated LTCC expression in both aging and hypertension.

Cost of treating hypertension in the elderly

Hypertension is a common disease among the elderly, a population that will continue to grow over the next decade. Untreated hypertension can lead to cardiovascular events and mortality. Given the seriousness of this disease and the increase in the number of elderly with hypertension, this review focuses on the cost of treating hypertension in the elderly as described in recent publications. We found a limited number of articles related to the treatment of hypertension in the elderly. One publication provided insightful information pertaining to expenditures in the United States for hypertension in 1998. This article was the first to examine age distribution among persons 65 years and older. It has been shown that antihypertensive pharmacologic treatment significantly reduces the incidence of cardiovascular events. Without any other medical conditions, thiazide-like diuretics are recommended for the treatment of hypertension in the elderly due to their beneficial effects, low risk for side effects, and low cost. In general, it was found that the elderly have higher expenditures per capita for hypertension and per hypertensive condition.

Clinical correlates of low blood pressure in very old people: the importance of cognitive impairment

OBJECTIVE

To identify the medical conditions associated with low blood pressure in very old people.

DESIGN

A population-based, cross-sectional study.

SETTING

Two neighboring communities in Stockholm, Sweden.

SUBJECTS

Participants were 319 male and 1070 female participants, with the mean age of 85.0 years (SD = 5.8).

MEASUREMENTS

Blood pressure recording, pulse rate counting, and Mini-Mental State Examination (MMSE) were conducted by trained nurses. Information on illness condition and activities of daily living (ADL) status was self-reported or gathered from proxy respondents. The computerized inpatient register system was also used for collecting the data of illness condition. Systolic pressure less than 130 mm Hg and diastolic pressure less than 70 mm Hg were defined as low systolic and diastolic pressure, respectively. MMSE score less than 24 was considered to indicate cognitive impairment.

MAIN RESULTS

In multiple logistic regression analyses, low systolic pressure was related to slower pulse rate (< or = 60 per minute), heart failure, ADL limitation, and cognitive impairment, and low diastolic pressure was related to increasing age, slower pulse rate, cardiac dysrhythmia, ADL limitation, and cognitive impairment. People with diabetes mellitus were less likely to be in the low systolic pressure group. 34.9% of the prevalence of low systolic pressure, and 17.9% of the prevalence of low diastolic pressure was associated with cognitive impairment.

CONCLUSIONS

Low blood pressure in the very old may be associated with poor functional status, cardiac insufficiency and, more importantly, cognitive impairment. It would be expected that low blood pressure is associated with increased mortality in this age group.