Heart disease, obesity and diabetes: what they mean for your kidneys

The body is an extremely complex system, with all vital organs linked via an enormous network of veins and arteries. As a result, any condition which affects one organ – such as heart disease – may, in time, come to affect other organs, such as the kidneys.

This is why kidney disease is often brought on by lifestyle conditions, like diabetes, heart disease and obesity.

Diabetes and your kidneys

Diabetic kidney disease – also known as diabetic nephropathy – is a common complication in patients with both Type I and II diabetes.

It occurs because diabetic patients often suffer a thickening or scarring of the nephrons, the structures within the kidneys that are responsible for maintaining the balance of fluid in the blood, removing waste and filtering the blood. When this happens, the kidneys begin to leak a protein called albumin into the urine. Symptoms of kidney failure include fatigue, a general malaise, nausea and vomiting accompanied by a poor appetite, swelling of the legs, irregular heartbeat, itchy skin, shortness of breath and a propensity to develop infections. However, it’s important to note that these symptoms may appear after damage has already occurred. People with diabetes are more likely to develop kidney disease if they smoke; if they are obese or have high blood pressure; were diagnosed with Diabetes I at a young age; or do not control their blood sugar. A genetic history of kidney disease is a further risk factor. If you have diabetes, it is important that your healthcare provider conducts regular tests to assess kidney function.

Heart disease

Although they have very different functions, the working of the heart inevitably impacts on kidney health. That’s because while the heart’s job is to keep oxygenated blood circulating around the body, it is the kidneys’ function to extract waste from the blood (in the form of urine). Kidneys also play a key role in regulating blood pressure by controlling levels of water and salt in the blood.

Here's the link: when the heart fails to pump blood effectively (as a result of heart disease), that blood fills its atriums and ventricles. This leads to pressure in the vein connecting the heart to the kidneys, and so the kidneys become congested with blood, too – however, that blood is not oxygenated. This, in turn, impacts the body’s hormonal system: in an effort to increase the supply of oxygenated blood to the kidneys, it forces the heart to pump harder. The heart, which is already stressed, experiences further strain.

Many of the risk factors which potentially lead to heart disease – such as high blood pressure – are present in patients with kidney disease. Meanwhile, kidney disease often increases a patient’s risk of developing heart disease, and vice versa. If you have heart disease, your doctor will check your kidney function as a matter of course. In the meantime, try to reduce your risk by weighing yourself regularly: drastic fluctuations in weight could indicate dehydration or an increase in fluid.

Obesity

Obesity is a red flag in terms of kidney health because it is a risk factor for other health conditions, such as heart disease and diabetes, which negatively impact kidney function. Added to that, obesity places strain on the kidneys: they have to work harder when the body is overweight, and are required to filter waste above normal levels. Obese people are also more likely to experience inflammation, which has the potential to damage kidneys. If you are obese, ask your medical practitioner to for advice around diet and exercise to help you lose weight and safeguard the health of your kidneys.