Posts Tagged "hypertension"

A growing stack of medical research—including Gottesman’s recent study—suggests that high blood pressure raises risk for thinking problems, early brain aging, and even Alzheimer’s disease. These three steps may help reduce risk:

Know your number. “Have your blood pressure checked regularly,” Gottesman says. “People tend to ignore high blood pressure, particularly when they are younger, because it has no symptoms that you can feel or see. But it’s important to pay attention to it.”

Take care of higher-than-normal blood pressure right away. Talk with your doctor about what blood pressure is appropriate for you. If yours is higher than recommended, your doctor will advise you take lifestyle steps such as weight loss, regular exercise, and a lower-sodium diet that features plenty of fruits and vegetables to bring it down to a healthier level. Your doctor may also prescribe drugs that lower blood pressure.

If your doctor prescribes medications for your blood pressure, take as directed. Nearly half of all people with high blood pressure don’t have it under control, according to the Centers for Disease Control and Prevention. One big reason: skipping medication or not taking it as directed.

It’s long been known that keeping your blood pressure within a healthy range helps protect against heart attack and stroke. Now a recent study from Johns Hopkins University has uncovered a new risk worth sidestepping: People with high blood pressure at midlife had greater decline in key thinking skills late in life than those with normal blood pressure readings.

Source: Johns Hopkins Medicine

Isolated systolic hypertension in young and middle-age adults was associated with an increased risk of death from cardiovascular causes later in life, according to a study done over 3 decades.

Men in the study with systolic blood pressure (BP) levels of 140 mmHg or higher and diastolic BP below 90 had a 28% increased risk for death from coronary heart disease compared with men with normal BP (hazard ratio 1.28, 95% CI 1.04-1.58), reported Donald M. Lloyd-Jones, MD, of Northwestern University Feinberg School of Medicine in Chicago.

In addition, women with isolated systolic hypertension (ISH) had a more than twofold greater death risk (HR 2.12, 95% CI 1.49-3.01) than women with optimal BP, they wrote in the Journal of the American College of Cardiology.

The findings provide strong evidence that ISH is a clinically meaningful condition in young and middle-age adults and not just pseudo or ‘white-coat’ hypertension, Lloyd-Jones told MedPage Today.

“It is not well supported by science, but there has been a belief by many that elevated systolic and not diastolic blood pressure in younger adults is benign,” he said. “Most previous research hasn’t really examined hypertension by subtype. That’s why we did this study.”

ISH is defined as a systolic BP of 140 mmHg or greater with a diastolic BP of less than 90 mmHg. It is common in the elderly, but relatively uncommon in younger and middle-age adults, the researchers wrote.

NHANES data suggest that the overall prevalence of ISH among adults in their 20s and 30s has more than doubled in recent decades, from 0.7% between 1988 and 1994 to 1.6% between 1999 and 2004, but there is still a great deal of uncertainty about the clinical consequences of ISH in younger adults.

Source: MedPage Today

A progressively rising blood pressure trajectory is not an inevitable part of aging in men who remain active and maintain high levels of cardiorespiratory fitness, a prospective, population-based study found.

The study included almost 14,000 men without high blood pressure, cardiovascular disease, or cancer at baseline followed for three and a half decades.

Men in the study who were categorized as having the lowest level of fitness, based on baseline treadmill tests, reached a systolic blood pressure (SBP) of >120 mmHg at approximately 46 years of age, compared with 54 years of age among those whose fitness levels were highest. Age-related diastolic blood pressure differences (DBP) were far more pronounced, with low-fitness men reaching >80 mmHg at approximately 42 years old compared with beyond age 90 in the highest fitness group.

“This suggests that highly fit men are likely to reach abnormal SBP values about a decade later than men in the low fitness category, implying that improving fitness levels may reduce the duration of elevated SBP,” researcher Junxiu Liu, MD, of the University of South Carolina Columbia, and colleagues wrote in the Journal of the American College of Cardiology, published online Sept. 15.

Exercise Keeps Heart Young

The study is one of two published in the issue suggesting that staying physically fit throughout life can keep aging hearts healthy.

In a separate investigation, researchers in Texas examined the impact of long-term exercise on left ventricular (LV) compliance and distensibility in around a hundred older men and women.

The study showed that while low levels of casual, lifelong exercise did not prevent decreased compliance and distensibility, four to five ≥30 minute exercise sessions a week throughout adulthood did prevent most age-related LV stiffness.

“This finding holds important implications for global health, as ventricular stiffening has been implicated in the pathophysiology of many common cardiovascular conditions affecting the elderly,” researcher Paul S. Bhella, MD, of the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, and colleagues, wrote.

Fit Men Had ‘Younger’ BP

The study by Liu and colleagues included an all male cohort from the Aerobics Center Longitudinal Study, which was a large study that included mostly white, college-educated people with middle to high socioeconomic status.

The men were between the ages of 20 and 90 at study entry, and they completed between three and 28 (mean 3.8) follow-up medical examinations between 1970 and 2006. Fitness was measured by a maximal treadmill exercise test, and longitudinal data were analysed using linear mixed models.

Cardiovascular fitness was assessed using the Balke maximal treadmill exercise test, with total treadmill time (highly correlated with oxygen uptake) used as an index of aerobic power. Participants were classified into low (<33rd percentile), moderate (33rd to 66th percentile), or high fitness categories (>66th percentile), according to the distribution of age-specific treadmill time.

Information on age, smoking status, and alcohol consumption were obtained by self-administered questionnaire. Body fat percentage was assessed using hydrostatic weigh in, skin fold thickness measurements, or both.

Among the key findings from the study:

-DBP tended to increase until nearly 60 years of age, when a decrease was observed, while SBP tended to increase over all age periods.

-Multivariate analysis revealed that average SBP increased by 0.30 mmHg (95% CI 0.29-0.31) with 1-year age increment after adjusting for body fat percent, fitness, resting heart rate, glucose level, triglyceride level, cholesterol level, current smoking, heavy alcohol consumption, and parental history of hypertension.

– had a yearly increase of 0.14 mm Hg (95% CI 0.13-0.15) before age 60 years.

-Overall, abnormal SBP (>120 mm Hg) began to occur at approximately 50 years of age and abnormal DBP (>80 mm Hg) began to occur at 60 years of age.

-Higher fitness levels significantly modified the risk in SBP trajectory across the lifespan, and the age-fitness interaction remained significant after adjusting for known hypertension risk factors.

Study strengths included the large number of participants, the longitudinal measure of SBP, DBP, and other time varying covariates, and the assessment of body fat percentage to measure obesity.

Limitations included the exclusion of women from the study, as well as the inclusion of only a small percentage (5%) of nonwhite and low income men, which limited its generalizability to these populations.

Findings May Not Apply to Women, Nonwhite Men

In an editorial accompanying the study, Stanley S .Franklin, MD, of the University of California Irvine, and Gary L. Pierce, PhD, of the University of Iowa, Iowa City, wrote that the exclusion of women was a major study limitation.

“There is some evidence that men have a steeper rate of increase in aortic stiffening beyond 50 years of age compared with women; therefore, fitness may have a different modifying effect on SBP and DBP trajectory with aging in women than men,” they wrote.

Even with the limitations, Franklin and Pierce wrote that the study suggests “habitual aerobic exercise may counteract the burden of cardiometabolic abnormalities that accelerate artery stiffening- characterized as ‘early vascular aging’ — and therefore slow the onset and severity of isolated systolic hypertension.”

Regular Exercise Preserves LV Function

In the study by Bhella and colleagues, 102 healthy older people (>64 years of age) were recruited and screened for lifelong patterns of exercise. The participants were stratified into four groups: sedentary (<2 ≥30 minute sessions/week), casual (2 to 3 sessions/week) committed (4 to 5 sessions/week) and competitive (6 to 7 sessions/week).

Right heart catheterization and echocardiography were performed while pre-load was manipulated using lower body negative pressure and rapid saline infusion to define LV pressure-volume relationships.

Peak oxygen uptake and LV mass increased with escalating doses of lifelong exercise, with little change in systolic function. At baseline, LV distensibility was greater in committed (21%) and competitive (36%) exercisers than in sedentary participants.

Group LV stiffness constants (sedentary: 0.062±0.039; casual: 0.079±0.052; committed: 0.055±0.033; and competitive: 0.035 ±0.033) revealed increased stiffness in sedentary subjects compared with competitive athletes, whereas lifelong casual exercise had no effect. They also showed greater compliance in committed exercisers than in sedentary or casual exercisers.

The researchers noted that sedentary aging, and the decreases in LV compliance and distensibility that accompany it, may set the stage for the cardiovascular conditions that affect the elderly, such as atrial fibrillation and heart failure with preserved ejection fraction.

In a commentary published with the study, Wilbur Y.W. Lew, MD, of the VA San Diego Healthcare System and the University of California San Diego, wrote that the effects of exercise on the heart are multifactorial and complex and that potential factors that prevent age-related changes in LV compliance include lowering blood pressure and arterial stiffness, decreasing cardiovascular comorbidities, improving endothelial function, and activating metabolic and signaling pathways to reduce chronic inflammation, fibrosis, and LV remodeling.

“A long-term commitment to exercise preserves LV compliance comparable to a young heart,” he wrote. “This may facilitate diastolic filling and preserve diastolic function. We face challenges to establishing causality, identifying mechanisms, and applying these results to an increasingly sedentary population.”

Source: medpagetoday.com