The Obesity Paradox and Kidney Disease
The January 2013 issue of the Journal of the American Medical Association published findings from an analysis of data from 97 research studies to determine risk of death based on body mass index (BMI). Surprisingly, the results show that people who are overweight (BMI 25-<30 kg/m2) and mildly obese (Grade 1 obesity, BMI 30-<35 kg/m2) had a lower risk of death compared to people with normal BMI (18.5-<25 kg/m2). This finding exists in people with heart attacks, strokes and heart failure.
The obesity paradox is not new to the kidney care community. In 2003 Dr. Kamyar Kalantar-Zadeh proposed the term reverse epidemiology to describe a protective survival benefit observed in hemodialysis and heart failure patients who were overweight and mildly obese. Higher cholesterol levels were also associated with reverse epidemiology.
So does this mean your weight does not matter when you have kidney or heart disease? Here’s some food for thought before you abandon your current eating plan.
- In the same analysis, people with a BMI 35 or greater had higher death rates than normal weight, overweight and mildly obese patients, so becoming more obese is a concern.
- Obese people are more likely to have chronic diseases like diabetes, high blood pressure and heart disease, which could mean they receive more medical care and monitoring compared to normal weight people.
- Excess weight may be a source of energy during illness or injury—a benefit the lean person does not have.
- A person can have different degrees of health and fitness regardless of their BMI or weight. Factors such as nutrition status, diseases, health history, where fat is stored (abdominal vs. lower body), exercise and eating habits influence your level of fitness.
I think these finding could make you less apprehensive about your weight. If you have a reason to lose weight, for example to qualify for a kidney transplant, or to decrease stress on your knee joints, don’t abandon your diet. The real message is to concentrate of what you can do to be healthier instead of obsessing over numbers on a scale or a low calorie diet plan. Exercise, even for 10-15 minutes and eating healthy foods play a big role in your health regardless of your weight.
Kidney diet resources from DaVita.com