Question

Adequate nutrition is a key component in maintaining a healthy immune system to defend against infectious diseases. Both deficient and excessive nutrients can harm the immune system. The same diet and lifestyle risk factors may contribute to several degenerative diseases. A person’s family history and laboratory test results can reveal strategies for disease prevention.

Plaques of atherosclerosis trigger hypertension and abnormal blood clotting, leading to heart attacks or strokes. Major risk factors for CVD include age, gender, and family history, which cannot be modified; and high LDL cholesterol and low HDL cholesterol, hypertension, diabetes, obesity, physical inactivity, smoking, and an atherogenic diet, which all can be modified by lifestyle choices.

Hypertension is a silent condition that progressively worsens atherosclerosis, and makes heart attacks and strokes likely. All adults should know their blood pressure numbers.

Cancer arises from genetic damage and develops in steps including initiation and promotion, which are thought to be sometimes influenced by diet.

1. Describe in your own words how obesity can increase the risk of diabetes and cardiovascular disease.

b.   How can diabetes increase the risk of cardiovascular disease?

c.   How does high blood pressure increase the risk of stroke?

Answer 1

Ans) a. Insulin resistance and inflammation are recognized as important links between obesity and cardiovascular disease (CVD). Plasma free fatty acids (FFA), either released from the abnormally enlarged adipose tissue or as part of the excessive nutrient intake, produce insulin resistance and inflammation.

- Both insulin resistance and inflammation are tightly linked to several independent CVD risk factors such as type 2 diabetes (T2DM), hypertension, dyslipidemia and disorders of blood coagulation.

- Several hypotheses have been proposed to explain how increased plasma FFA levels can cause insulin resistance including a) the lipid metabolite hypothesis, b) the inflammation hypothesis, c) the hyperinsulinemia hypothesis and d) the endoplasmic reticulum (ER) stress hypothesis.

- The latter does not require presence of elevated plasma FFA levels and thus provides a mechanism to explain the development of insulin resistance and inflammation in all obese individuals, i.e., those with and without elevated plasma FFA levels.

- Hyperinsulinemia per se has been suspected to cause CVD based on epidemiologic studies which have associated chronic hyperinsulinemia with CVD without, however, establishing a cause and effect relationship.

- There are, however, newer results which support the hypothesis that chronic hyperinsulinemia per se can promote the development of CVD.

- For instance, hyperinsulinemia can activate triglyceride formation, several matrix metalloproteinases (MMP), and the tissue factor pathway of blood coagulation, all of which are known to be associated with CVD, even in the presence of "metabolic insulin resistance".

b. Diabetes is treatable, but even when glucose levels are under control it greatly increases the risk of heart disease and stroke.

- That's because people with diabetes, particularly type 2 diabetes, may have the following conditions that contribute to their risk for developing cardiovascular disease.

- For overall cardiovascular health, the American Heart Association recommends:

- At least 150 minutes of moderate-intensity aerobic activity or 75 minutes of vigorous aerobic activity per week (or an equivalent combination of moderate-and vigorous-intensity activities), plus moderate-to high-intensity muscle-strengthening activity at least 2 days per week for additional health benefits.

• High blood pressure (hypertension)
  High blood pressure has long been recognized as a major risk factor for cardiovascular disease. Studies report a positive association between hypertension and insulin resistance. When patients have both hypertension and diabetes, which is a common combination, their risk for cardiovascular disease doubles.
  
• Abnormal cholesterol and high triglycerides
  Patients with diabetes often have unhealthy cholesterol levels including high LDL ("bad") cholesterol, low HDL ("good") cholesterol, and high triglycerides. This triad of poor lipid counts often occurs in patients with premature coronary heart disease. It is also characteristic of a lipid disorder associated with insulin resistance called atherogenic dyslipidemia, or diabetic dyslipidemia in those patients with diabetes. Learn more about cholesterol abnormalities as they relate to diabetes.
  
• Obesity
  Obesity is a major risk factor for cardiovascular disease and has been strongly associated with insulin resistance. Weight loss can improve cardiovascular risk, decrease insulin concentration and increase insulin sensitivity. Obesity and insulin resistance also have been associated with other risk factors, including high blood pressure.
  
• Lack of physical activity
  Physical inactivity is another modifiable major risk factor for insulin resistance and cardiovascular disease. Exercising and losing weight can prevent or delay the onset of type 2 diabetes, reduce blood pressure and help reduce the risk for heart attack and stroke. It's likely that any type of moderate and/or vigorous intensity, aerobic physical activity—whether sports, household work, gardening or work-related physical activity—is similarly beneficial.
• Poorly controlled blood sugars (too high) or out of normal range
  Diabetes can cause blood sugar to rise to dangerous levels. Medications may be needed to manage blood sugar.
  
• Smoking
  Smoking puts individuals, whether or not they have diabetes, at higher risk for heart disease and stroke. Learn how to kick the habit.

c. Individuals with insulin resistance or diabetes in combination with one or more of these risk factors are at even greater risk of heart disease or stroke. However, by managing their risk factors, patients with diabetes may avoid or delay the development of heart and blood vessel disease. Health care provider will do periodic testing to assess whether you have developed any of these risk factors associated with cardiovascular disease.