SPRINT trial redefines blood pressure targets

More than 70 million people in the United States suffer from hypertension – which presently is defined by a systolic blood pressure of higher than 140 mm Hg and a diastolic of higher than 90 mm Hg.  A landmark study called SPRINT (Systolic Blood Pressure Intervention Trial) challenges the accepted guidelines of optimum level for systolic blood pressure and provided information about benefits and shortcomings of intensive pharmacotherapy. The study was published in NEJM was interrupted nearly two years early, when it became apparent that lower blood pressure for most people over 50 prevented heart problems and deaths.

In the SPRINT trial, 14,692 patients were assessed for eligibility, and 9361 individuals with a systolic blood pressure of 130 mm Hg or higher and an increased cardiovascular risk, but without diabetes, were randomly assigned in two groups; a systolic blood-pressure target group of less than 120 mm Hg (intensive treatment) or a target group of less than 140 mm Hg (standard treatment).

The primary outcomes were myocardial infarction, other acute coronary syndromes, stroke, heart failure, or death from cardiovascular causes.

At 1 year, the mean systolic blood pressure was 121.4 mm Hg in the intensive-treatment group and 136.2 mm Hg in the standard-treatment group. The mean number of blood-pressure medications was 2.8 in the intensive-treatment group and 1.8 in the standard-treatment group.  The intervention was stopped early after a median follow-up of 3.26 years owing to a significantly lower rate of the primary composite outcome in the intensive-treatment group than in the standard-treatment group (1.65% per year vs. 2.19% per year; hazard ratio with intensive treatment, 0.75; 95% confidence interval [CI], 0.64 to 0.89; P<0.001). All-cause mortality was also significantly lower in the intensive-treatment group (hazard ratio, 0.73; 95% CI, 0.60 to 0.90; P=0.003).

Investigators found that there were 27% fewer deaths (155 compared with 210) and 38% fewer cases of heart failure (62 compared with 100) among patients who achieved the systolic pressure target of 120 mm Hg than among those who achieved the current 140 mm Hg target.

The lower relative risk of major cardiovascular events observed across subgroups defined according to age, sex, race, medical history, and baseline blood pressure among patients who achieved the systolic pressure target of 120 mm Hg in comparison to those who achieved the currently recommended level of 140 mm Hg.

Rates of serious adverse events of hypotension, syncope were 67% and 33% higher in the intensive therapy group.   Electrolyte abnormalities, and acute kidney failure were noted but injuries due to falls surprisingly were not more common, as had been feared among the elderly in the intensive-treatment group.

The research indicated that among patients over 50 at high risk for cardiovascular events who are not diabetics, targeting a systolic blood pressure below the current guidelines of 140 or 150 mm Hg to less than 120 mm Hg, prevented heart disease and strokes and thus save lives.

DOI: 10.1056/NEJMoa1511939

Cancers linked to Obesity

Obesity is a major contributor to the development of cancer.  According to the National Cancer Institute obesity is associated with increased risks for cancer of the esophagus, pancreas, colon and rectum, breast (after menopause), endometrium, kidney, thyroid, and gallbladder.

 

NHANES 2007-2008 survey found 68 percent of the U.S. adults age 20 years and older are overweight or obese and 17 percent of children and teens ages 2 to 19, are obese.  According to NCI Surveillance, Epidemiology, and End Results (SEER) data, it is estimated that in 2007 in the United States, about 34,000 new cases of cancer in men (4 percent) and 50,500 in women (7 percent) were due to obesity.

In 2003, Calle et al published in NEJM the results of a study of more than 900,000 healthy adults that were followed for 16 years.  The study authors concluded that excess fat could account for 14% of all deaths from cancer in men and 20% of those in women.

A recent study of 92,834 British women enrolled in a database for cancer screening, Fourkala et al reported in an article published in BMJ Open that women who go up a skirt size every decade between their 20s and their 60s are at increased risk of postmenopausal breast cancer.  They also found that “an increase of one size every 10 years led to a 33 percent rise in the risk of postmenopausal breast cancer, while an increase of two sizes per decade led to a 77 percent rise in risk.

Bhaskaran et al study of 5.2 million adults that was published in Lancet found that 166 955 individuals developed cancer and that body-mass index (BMI) was associated with 17 of 22 cancers.  Although the effects varied substantially by site, increase in BMI was roughly linearly associated with cancers of the uterus, gallbladder, kidney, cervix, and leukemia.  BMI increase was positively associated with liver, colon, ovarian, and postmenopausal breast cancers overall. They estimated inverse associations with prostate and premenopausal breast cancer risk, both overall and in non-smokers. By contrast, for lung and oral cavity cancer, they observed no association in non-smokers.  Assuming causality, 41% of uterine and 10% or more of gallbladder, kidney, liver, and colon cancers could be attributable to excess weight. They conclude that extra weight could contribute to more than 12,000 cases of cancer in the UK population every year.

Related Resources:

Physical Activity and Cancer

Energy balance: Weight and Obesity, PhysicalActivity, Diet

The Mediterranean Diet

The Mediterranean diet is derived from the traditional diets of Greece, southern Italy and Spain.  Its uniqueness relates to the use of olive oil instead of butter and the daily consumption of nuts, legumes, fruits and vegetables.  People in the Mediterranean countries depending on their local (island, valleys or mountains) eat moderate amount of fish, or meat such as poultry and/or dairy products (mostly as cheese and yogurt).  They also drink a low amount of wine and/or spirits.  According to the American Heart Association, there's no one "Mediterranean" diet but a dietary pattern that includes the above-mentioned foodstuff and the use of olive oil a monounsaturated fat that does not raise blood cholesterol.

The incidence of heart disease and death rates in Mediterranean countries is lower than in the United States.  Although diet appears to have a role, other factors such as genetic, lifestyle, physical activity and extended social and family support systems may also play a part.

Before advising people to adhere to a strict Mediterranean diet, well designed and controlled studies are needed to determine whether the diet itself or other factors (genes, lifestyle, social) account for the lower deaths from cardiovascular disease among humans.  The findings from the following two studies are supportive of the beneficial effect the Mediterranean diet and the consumption of nuts has in our health. 

An important multi-center study that was conducted in Spain was published in the New EnglandJournal of Medicine.  The authors evaluated the effect of the Mediterranean diet in the prevention of cardiovascular disease in individuals who were at high risk for cardiovascular events, but with no apparent cardiovascular disease. A total of 7447 persons were enrolled whose age ranged from 55 to 80 years; with a male to female ratio 43 to 57 percent were randomly assigned, to one of three diets: a Mediterranean diet supplemented with extra-virgin olive oil, a Mediterranean diet supplemented with mixed nuts, or a control diet (advice to reduce dietary fat). The end point was the rate of major cardiovascular events such as myocardial infarction, stroke, or death from cardiovascular causes. A primary end-point event occurred in 288 participants.  The group assigned to a Mediterranean diet with extra-virgin olive oil experienced 96 events while and the group assigned to a Mediterranean diet with nuts experienced 83 events, respectively, versus 109 events in the control group. On the basis of these results, the trial was stopped after a median follow-up of 4.8 years as the authors concluded that among persons at high cardiovascular risk, a Mediterranean diet supplemented with extra-virgin olive oil or nuts reduced the incidence of major cardiovascular events.

According to a study from the USA that was also published in the New England Journal of Medicine, people who ate a daily handful of nuts were less likely to die from any cause over a 30-year period and were more slender than those who didn’t consume nuts.  For their research, the authors analyzed information from the Nurses’ Health Study that provided data on 76,464 women, and the Health Professionals’ Follow-Up Study that provided data on 42,498 men. The researchers report a 29% reduction in deaths from heart disease and an 11% reduction in death rate from cancer.  It appeared that the protective effect was similar to all types of nuts.  Those who ate nuts less than once a week had a 7 percent reduction in mortality; once a week, 11 percent reduction; two to four times per week, 13 percent reduction; five to six times per week, 15 percent reduction; and seven or more times a week, a 20 percent reduction in death rate. 

Based on this and other smaller studies, the U.S. Food and Drug Administration concluded that eating 1½ ounce per day of most nuts “may reduce the risk of heart disease.”