Current dietary guidelines emphasize an approach based on dietary patterns, rather than individual access to foods and nutrients, to prevent and manage cardiovascular disease. The most complete healthy eating pattern is the Mediterranean diet and Dietary Approaches to Stop Hypertension (DASH). Both dietary patterns were equally rich in fruits, vegetables, legumes, nuts, and seeds, with moderate intakes of fish, seafood, poultry, and dairy products, and low intakes of red and processed meats and sweets. The Mediterranean diet also promotes heavy use of olive oil and regular but moderate consumption of wine (especially red wine).
The Mediterranean Diet
The Mediterranean diet generally refers to the eating styles of southern European countries on the Mediterranean coast, such as Greece, Spain, France and southern Italy. It emphasizes more vegetables, fruits, fish, seafood, beans, nuts, followed by cereals, and uses vegetable oil (containing unsaturated fatty acids) instead of animal oil (containing saturated fatty acids). Rather, the Mediterranean diet especially promotes the use of olive oil. A 2019 Cochrane review of randomized controlled trials (RCTs) found a significant beneficial effect of the Mediterranean diet on diastolic blood pressure (DBP) and systolic blood pressure (SBP). In addition, a meta-analysis of 16 RCTs found that Mediterranean diet was associated with weight loss.
The DASH Diet
The DASH diet is a diet developed by a large-scale hypertension prevention and control program (Dietary Approaches to Stop Hypertension; DASH) in the United States in 1997. It was found that if the diet can have enough vegetables, fruits, low-fat (or skim) milk to maintain adequate intake of potassium, magnesium, calcium and other ions, and minimize the amount of fat in the diet (especially animal fat rich in saturated fatty acids), then it can effectively lower blood pressure. Therefore, the DASH diet is often used as a dietary pattern for the prevention and control of hypertension. Compared with the Mediterranean diet, the DASH diet have stronger BP-lowering effects. A meta-analysis of 24 randomized controlled trials (RCTs) of dietary pattern interventions found that the DASH diet had a strong effect to reduce SBP (−7.6 mmHg [95% CI, −10.0 to −5.3]) and DBP (−4.2 mmHg [95% CI, −5.9 to −2.6]). When weight loss was combined with exercise intervention, the effect of DASH diet on lowering blood pressure was significantly stronger (16.1/9.9 mmHg) than DASH diet intervention alone (−11.2/7.5 mmHg). In addition, the antihypertensive effect of the DASH diet was more pronounced when combined with low sodium intake, especially in people with hypertension. In the DASH-Sodium trial, compared with the DASH diet with high sodium intake (3450 mg/d), the DASH diet with low sodium intake (1150 mg/d) reduced SBP by 0.9 mmHg (95% CI, −2.1 to 0.3), 3.3 mmHg (95% CI, −4.7 to −1.9), 4.9 mmHg (95% CI, −7.3 to −2.6), and 10.4 mmHg (95% CI, −15.5 to −5.3) in adults with baseline SBP < 130, 130 to 139, 140 to 149, and ≥150 mmHg, respectively.
Aside from dietary patterns, low sodium intake alone has also been shown to be beneficial for blood pressure control. And the effect of lower sodium intake on blood pressure was particularly pronounced in older adults, hypertensive groups and black individuals. In addition to this, increasing potassium intake can also lower blood pressure, although too much potassium intake can be counterproductive.
In addition to the widely recommended ways to improve your diet above, several experiments have investigated the timing of your meals for weight loss and blood pressure control. Small clinical studies in people with metabolic syndrome suggest that intermittent eating may moderately reduce systolic and diastolic blood pressure, similar to weight loss through other interventions to lower blood pressure.
Physical Activity (PA)
Physical activity (PA) is defined as a physical movement produced by skeletal muscle contraction that increases energy expenditure above resting levels. Exercise is moderate-to-vigorous-intensity PA, planned, structured, and repetitive, designed to improve and maintain health.
Physical Activity Lowers Blood Pressure
There is evidence that physical activity (PA) and exercise training (ET) reduce obesity, hypertension, and obesity-related hypertension. Current recommendations are to lose at least 5%-10% body weight over 6 months to reduce cardiovascular risk factors and other relevant cardiometabolic risk factors (including insulin sensitivity, arterial stiffness, and resting blood pressure).
Studies have found that weight loss of 5%-10% can reduce systolic and diastolic blood pressure by more than 5 mmHg and 4 mmHg, respectively, and weight loss of 10 kg can reduce systolic blood pressure by 5-20 mmHg.
Reducing Sedentariness to Reduce BP
There is increasing evidence that reducing sedentary periods (ie, the time spent sitting or interrupted by walking or standing) can reduce systolic or diastolic blood pressure by 1-16 mmHg. The effect of reducing sedentary time on blood pressure lowering is more pronounced in people with hypertension.
It should be noted, however, that although weight loss due to dietary changes and physical activity are effective strategies for lowering blood pressure, the recurrence rate of hypertension is higher in those who undergo such lifestyle interventions. According to a review of prospective trials, the positive effects of weight loss on blood pressure were significantly reduced or reversed over time. This reversal is often associated with weight regain. Weight loss gains that are successfully maintained over the years therefore require high levels of physical activity and limited sedentary, frequent weight monitoring and long-term dietary restrictions.
Medications for weight management may be considered in patients with limited weight loss through lifestyle modification alone and in patients with obese hypertension. Anti-obesity drugs can be used as an adjunct to diet and exercise. The U.S. Food and Drug Administration (FDA) has approved four drugs for the short-term (up to 12 weeks) treatment of obesity: phentermine, diethylpropion, phendimetrazine, and benzphetamine. Currently, 5 drug therapies are approved by the FDA for long-term weight loss: orlistat, phentermine/topiramate extended release, naltrexone/bupropion, liraglutide 3.0 mg, and semaglutide 2.4 mg weekly subcutaneously. In randomized controlled trials (RCTs), drugs approved for long-term use (along with lifestyle changes) resulted in an average of 3%-9% weight loss over placebo (lifestyle changes) over a 1-year period.
Before receiving medication, patients must be clearly informed about the safety and possible adverse effects of taking weight-loss medications. For example, the most common side effects of phentermine are constipation, dizziness, dry mouth, and insomnia; orlistat has a generally good safety profile due to its peripheral mechanism of action. However, it is often poorly tolerated because of a high incidence of loose stools, fecal urgency, and flatus when patients do not strictly adhere to a low-fat diet. Patients taking orlistat should take a multivitamin concomitantly to supplement the reduced absorption of fat-soluble vitamins. All medicines must be taken under the guidance of a doctor.
There were 216,000 metabolic surgeries performed in the United States in 2016. Sleeve gastrectomy was the most common metabolic procedure (58%), followed by Roux-en-Y gastric bypass (RYGB; 19%), adjustable gastric band (3%), and biliopancreatic diversion with duodenal switch (0.6%). Currently, over 98% of metabolic surgeries are performed laparoscopically, with major perioperative morbidity less than 5%, mortality less than 0.2%, hospital stay of 1 to 2 days, and recovery time of 2 to 4 weeks.
Generally, these procedures involve some degree of gastric volume reduction or intestinal bypass. Weight loss and metabolic improvement are currently thought to be driven primarily by neuroendocrine mechanisms that reduce appetite and enhance satiety, as well as improve insulin sensitivity and secretion. In addition, intestinal bypass surgery can lead to a decrease in the absorption of calories, which further reduces total calorie intake.
We should notice that not everyone is suitable for metabolic surgery. Generally, patients with a BMI ≥40 kg/m2 or ≥35 kg/m2 with comorbidity can be candidates for MS if they are psychologically stable and without substance abuse problems. Patients with type 2 diabetes and a BMI ≥30 kg/m2 (Asian patients ≥27.5 kg/m2) may also be candidates for MS if they are not in good glycemic control when on reasonable medical therapy. Metabolic surgery should be performed at the center with a multidisciplinary team that includes bariatric surgeons, endocrinologists/diabetes specialists, cardiologists, anesthesiologists, psychologists, and dietician with expertise in obesity and diabetes care.
Perioperative morbidity and mortality associated with metabolic surgery have decreased significantly since the introduction of minimally invasive surgery in the 1990s. The U.S. National Hospitalized Patient Sample Database showed an overall hospitalized morbidity rate of 9% and a risk of death of 0.1%. At present, the perioperative complication rate of metabolic surgery is comparable to that of laparoscopic cholecystectomy, laparoscopic appendectomy or hysterectomy, which means that for patients who can undergo metabolic surgery after scientific evaluation, the risk of surgery has been greatly reduced.