Obesity and Kidney: An "unknown" risk factor for Kidney Disease

According to the World Health Organization, obesity is defined as abnormal or excessive fat accumulation that may repair health. Obesity is the phenotypic feature of metabolic syndrome (also referred to as dysmetabolic syndrome), which is characterized by insulin resistance, hyperinsulinemia and dyslipidemia. The metabolic syndrome contributes to the development of type II diabetes, hypertension and cardiovascular disease. 

In 2014, more than 1.9 billion adults were overweight and οf these 600 million were obese. By 2025, it is estimated that obesity will affect 18% of men and more than 21% of women, and severe obesity will affect 6% of men and 9% of women overall around the world. In some countries, obesity is evident in more than one third of the adult population resulting overall in poor health and increased annual medical expenses.

Obesity is a crucial independent risk factor for the development of Chronic Kidney Disease (CKD) or deficiency as widely known. People who are overweight or obese are 2 – 7 times more likely to develop end-stage CKD than those who are of normal weight. This can occur indirectly, increasing the risk of the main risk factors that predispose to CKD, such as diabetes mellitus and hypertension, but also with a direct impact on both the onset and development of CKD, as well as to its deterioration to end-stage renal disease (ESRD.  Ιn obese individuals, the kidneys must work harder, with more blood filtration than normal (ultrafiltration) to meet the metabolic demands of the increased body weight, and the increase in function can ultimately damage the kidney in the long-term and increase the risk of developing kidney disease.

Recently, another independent mechanism has been studied, through which obesity worsens renal function. More specifically, this mechanism is insulin resistance which promotes chronic kidney damage. Insulin is known to affect the growth of cells in the kidney, but it also increases the rate at which the kidney filters the blood. Many studies have demonstrated the relationship between insulin resistance / hyperinsulinemia and CKD. This correlation has even been proved to exist before the onset of diabetes, when insulin resistance appears. Therefore, kidney damage starts at the very early stages of obesity before it leads to the appearance of diabetes mellitus.

A third mechanism is fat accumulation in the body. In this fatty tissue, many substances are produced with damaging effects on the kidney, especially when they have a long effect on it. Kidney damage caused by obesity, unfortunately, has no symptoms except for when it causes severe CKD. The process leading to kidney damage is slow and requires a fair amount of time. But when the damage has been done it is permanent and irreversible.

But the positive aspect is that obesity can be prevented and / or reduced, so the progression of CKD can be slowed or even reversed in time. Education and public awareness regarding the dangers of obesity and the benefits of a healthy lifestyle including proper nutrition and exercise can greatly help in preventing obesity and kidney disease and the pathologies that accompany it.

The aim of health professionals should include the promotion of education about the harmful effects of obesity and its relation to kidney disease, emphasizing the fact that it increases the likelihood of its occurrence, but also it worsens and develops the existing kidney disease in fast pace. Also, supporting healthy lifestyles and promoting health policy measures that induce preventative behaviors from the public are extremely important including lifestyle intervention, calorie restriction and increased physical activity. And let’s shall not forget that the best way to fight CKD is to prevent it!

Some useful tips are the following:

- Good regulation of blood pressure and regular blood pressure control

- Excellent control of diabetes mellitus

- Good physical condition and physical activity (eg. 30 min. walk per day)

- Healthy Nutrition

- Beware of your body weight

- Stop smoking

The benefits of the above are multiple with positive effects on our life and health. The reverse causes serious, and most of the time, permanent damages.

Mesogeios Dialysis Centers Group Scientific Team

Bibliography 

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