What is the link between hypertension and obesity?
The seemingly inevitable rise in blood pressure as we age is much more pronounced in the developed world. Western diet and lifestyle habits seem to be the root cause. This is due to arteriosclerosis, the stiffening of blood vessels that is caused by elevated blood fats.
Excess weight can either cause, or aggravate hypertension. If you are overweight your risk for developing hypertension is six times greater. If your are obese, it is eight times greater.
Am I overweight?
It may sometimes be difficult to distinguish between a healthy weight, and the artificial ideal body image, as portrayed by the media. Rather use the Body Mass Index (BMI) to assess your weight. This is a scientific tool that looks at your weight to height index. A BMI of 19 to 24 is within normal limits. 25 to 29 is overweight, and 30 and higher is seen as obese. If you are obese it means you are 20% or more above your ideal weight.
What is the role of body-shape?
If you tend to carry excess weight around the waist, you are more “apple-shaped”. Men especially, tend to gain weight around the belly. The fat in this abdominal area is more metabolically active. The fats are released in the circulation and ends up in the blood vessels. This body shape is associated with greater health risks, particularly cardiovascular disease and diabetes. Measuring and keeping an eye on your waist circumference is very helpful. In the typical female shape, fat is mainly confined to the hips, buttons and thighs. This “pear-shaped” body seems to have a lower health risk.
What factors commonly lead to being overweight?
Genetic influence is strong, and a family history of obesity makes you more prone to being overweight. It may determine your metabolic rate of burning fat. Keep in mind, however, that families also tend to have similar lifestyle habits. Some studies suggest that overfeeding during childhood can increase the amount of fat cells in the body.
Gender also plays a role, and being male is usually an advantage. Due to the male hormones, men tend to have more muscle. Muscle tissue is more metabolically active and burns more energy, even at rest.
A sedentary lifestyle, a modern day trend, is a major contributor to weight gain. Alarmingly, this also accounts for the rising number of obese children. The other contributor is the high fat and refined food content in the Western diet. Over-eating and under-exercising inevitably leads to weight gain.
Does losing excess weight really help control my hypertension?
Dropping those extra kilos seems to be the most effective way of lowering blood pressure, without using drugs. People with borderline or stage I hypertension, are often able to control their blood pressure with lifestyle modification alone. If added drugs are needed, it can reduce the dosages required.
Hypertension cannot always be controlled with weight loss alone, because your genetic blueprint and other factors also play an important role. However, losing excess weight has many other advantages to offer your cardiovascular system. This includes the lowering of harmful blood fats, LDL cholesterol and triglycerides, that lead to arteriosclerosis. A healthy body weight also decreases the risk of developing adult-onset diabetes.
What other lifestyle modifications are needed?
The correct body weight and composition is an indispensable part of maintaining physical fitness. To achieve the best result, however, it must be combined with a holistic health plan. This includes regular exercise, not smoking, avoiding excess alcohol, salt, saturated fat and refined foods. Eating ample portions of fruit, vegetables and low fat dairy helps supply minerals and anti-oxidants. Fatty fish like salmon, mackerel and tuna contain essential fatty acids that are good for the heart.
What diet should I follow?
The DASH (Dietary Approaches to Stop Hypertension) diet is a user-friendly eating plan. It includes foods with a low salt content and rich in potassium, calcium and magnesium. High fibre, wholegrain products, low fat dairy, lean meat and fish, legumes, nuts, fruit and vegetables are recommended. In a recent trial, patients showed significantly reduced systolic and diastolic readings after eight weeks on this diet. In the group with more marked hypertension, the reduction of systolic and diastolic blood pressure was 11.4 and 5.5 mmHg respectively. If the general population were to achieve such reductions, it is estimated that heart disease will decrease with 15% and stroke with 27%.
What is the deadly quartet?
The consequences of obesity are many and can vary from arthritis in the weight bearing joints to hypertension. For people with a genetic predisposition, it may lead to a dangerous constellation of risk factors - hypertension, obesity, abnormal blood fats and diabetes or insulin resistance. Abnormal blood fats refers to raised LDL cholesterol (bad cholesterol), low HDL cholesterol (good cholesterol), and high triglycerides. Insulin resistance means a decrease in the body’s ability to metabolise and store sugar in the muscle. The cells do not respond to insulin and more insulin is secreted in response. The blood levels of insulin become elevated. Eventually it leads to adult onset diabetes or Diabetes Mellitus Type II.
The quartet of (upper body) obesity, hypertension, abnormal blood fats and insulin resistance or diabetes, is a health hazard. It leads to cardiovascular damage like heart attack, stroke, heart- and kidney failure, retinal damage (sight) and blood vessel abnormalities.
How should I go about losing weight?
Firstly, you should know exactly what you want to achieve. Do your BMI and determine how many kilograms you need to lose. Remember that body composition is very important, which means that lean muscle must be preserved. Muscle adds to weight and therefore you need not become a slave of the scale. How your clothes fit, and your mirror are good progress tools.
Your goals must be written down, not only your target weight but also your goal blood pressure. Keep your goals realistic and manageable, but not static. Be prepared to adapt to changing circumstances.
Focus on improving your health in general, and not only on being “slim”. Add to your list the other benefits you can achieve by losing excess fat. These are things like more energy, greater productivity, a better sex life and keeping up with the children.
Have a written plan of action. This will look at effective time-management to accommodate your new lifestyle. Always talk to your doctor before starting an exercise routine, and then start moving.
Do not despair if you dislike the “health-club” scene. Find any form of movement that you could enjoy, and do that regularly. That could be walking the dog, tap-dancing or martial arts. Commit yourself to exercise at least four times a week from the start, even if you can manage only 10 minutes at a time initially. Some people enjoy the support of a group, which has the added benefit of social interaction. Join or start a group.
Study the dietary options available. The DASH eating plan is a good starting point. There is no shortage of diets or nutritionists that can help you. Motivation, however, can be elusive at times. That is why you have to determine your goals first, and write it down.
Do not give up if you defaulted on your masterplan. It is not about putting in a huge effort for a week. It is about making small, permanent, consistent changes to your lifestyle habits. Over-commitments that are not sustainable could just erode your selfbelief.
(Written by Dr Kathleen Coetzee, MBChB.)