Chronic Kidney Disease: Are we ready for the next epidemic?

Kidney diseases have long been associated with stigma. In the medical field, it's observed that individuals are often willing to openly discuss specific ailments such as heart diseases, sometimes even taking pride in sharing their experiences. However, when it comes to certain other illnesses, there's a noticeable reluctance to even mention them. Kidney diseases unfortunately fall into this latter category, which isn't entirely unexpected. The term 'kidney disease' alone can evoke daunting images, particularly of elderly individuals struggling for breath as they're connected to dialysis machines linked with monitors and blood-filled tubes. However, these perceptions are far from accurate. The reality is that kidney diseases are prevalent across various age groups, and not all cases necessitate dialysis treatment.

The most common kidney disease we encounter is what we call chronic kidney disease (CKD). Simply put, it is a progressive loss of kidney function lasting for more than 3 months. Recent estimates show that around 17 % of our population has CKD in one form or the other. That means 1 out of 6 Indians has CKD. These numbers may be eye-popping to many, but hardly surprising given the fact that the majority of those affected are not aware that they have CKD.

The major causes for CKD in our adult population, as in many countries of the world are diabetes and hypertension. Other less common causes include glomerular diseases, stone disease and cystic diseases of the kidney.

Symptoms

The symptoms of CKD are varied and not always evident. Early stages of CKD may be totally asymptomatic and the person may be unaware till it is picked up by blood or urine investigations or an imaging like an ultrasound (done for some other reason). Others can present with symptoms like swelling of legs and face and frothy urine. As the disease advances, the swelling may worsen and a few may develop symptoms like nausea, vomiting, loss of appetite and loss of weight, which in many cases may be mistaken for an entirely different disease.

Early diagnosis is the key

Irrespective of cause, most people with CKD, if detected and diagnosed early can be managed well. This holds especially true for CKD secondary to diabetes and hypertension. The most important investigations are blood investigations like creatinine levels and urine tests looking for protein leak in urine, both of which if done early can pick up CKD in a timely and accurate fashion. There are however a few issues pertaining to these tests. The first is the fact that both these tests are not standardized across all the laboratories. So, a person can get different test results even on the same day, which only adds to the confusion. The second is the fact that some investigations like the blood creatinine levels are expressed as numbers, which in many instances don’t actually convey the gravity of his/her condition. Many people with marginally elevated or marginal changes in their blood levels ( of markers like creatinine) are misled into thinking (by themselves or others) that they don’t have any troubles. It is imperative to understand that even small changes (as conveyed by numbers) may sometimes indicate a significant change in kidney function and need to be taken seriously and looked into.

Getting sidetracked

Another issue which needs to be addressed is the abundance of practitioners of alternative systems of medicine, who are lacking in expertise and knowledge to diagnose or deal with many of these diseases. Many of the treatments and medications used in these systems are not standardised and their exact compositions and proportions are a mystery. Since kidneys are the major excretory pathway for most body toxins and medications , all of these are routed through the kidneys. It is therefore no surprise that many patients, especially those with preexisting kidney ailments develop worsening kidney function after a course of such medicines, at which point significant damage has already occurred which cannot be completely reversed.

Retarding Progression

It is important to realize that it may not be possible to completely recover the loss of function in a patient with chronic kidney disease. At the same time, we should realize that small deficits in function can be compensated by the kidneys well. Hence, the main aim once a chronic kidney disease has been diagnosed is to retard its progression.

The most important step in retarding the progression of chronic kidney disease is control of hypertension (if the patient is hypertensive). Though more stringent control has been suggested, a realistic target for most patients to achieve is a BP of less than 130/80 mm hg. This is usually achieved by a combination of salt restriction and antihypertensive drugs. Salt restriction to less than 5g/day is usually recommended. In simple terms, this translates to less than 1 teaspoon of salt per day. ( 1 teaspoon is 5 g and 1 tablespoon is 15 g). This of course is much easier said than done because this entails a careful titration of the salt added to various food items and salt is an indispensable part of many of our staple food items. Another problem at times is the difficulty of other family members in adjusting to a low salt diet in cases where food cannot be prepared exclusively for the suffering person.

Salt restriction alone is not enough and all patients will need to be on antihypertensive medications. Antihypertensive medications belong to different classes and most patients will require a combination of multiple antihypertensive medications to achieve their target BP levels.

Equally important is diabetic patients is optimal control of blood sugar levels which in addition to preventing worsening of kidney function will also ameliorate effects on other organ systems including heart, eyes and nerves.

Another important facet of retarding progression is control of proteinuria. Normal kidneys do not usually filter significant amounts of protein in the urine. Protein leak in the urine, called proteinuria, may appear early or late in the course of a chronic kidney disease. It may be asymptomatic or cause symptoms like swelling of legs, face, abdomen and breathing difficulty. Constant protein leak in the urine leads to progressive kidney damage and progression of chronic kidney disease. Hence, it is imperative to control this. This is achieved with good BP control and certain medications which act on the kidneys and may reduce/stop the protein leak.

Other equally important aspects for these patients include maintaining good nutrition, a healthy lifestyle including regular exercise and weight loss for overweight and obese individuals.

It's not just the kidneys

The most common causes and risk factors for chronic kidney disease include diabetes and hypertension. These also happen to be risk factors for a host of other ailments including cardiovascular diseases, stroke, neuropathy and retinopathy. In many patients with chronic kidney disease, the kidney involvement may actually be mild while these other diseases predominate. For example, more than half of all deaths in patients with CKD can be attributed to cardiovascular diseases. Similarly, the prevalence of eye involvement in the form of retinopathy and peripheral nerves in the form of neuropathy is quite high. So, any diagnosis of chronic kidney disease necessitates a vigorous search for and management of these diseases, especially cardiovascular diseases.

Bursting myths

When it comes to renal diseases, myths abound in plenty. The most common one is that once you are diagnosed with a kidney disease, dialysis is inevitable. Nothing could be farther from the truth. The fact remains that most of the cases of chronic kidney disease, especially if diagnosed early and treated well, do not progress at all or progress extremely slowly so that only a small proportion of them reach end-stage renal disease where dialysis may be needed. Even in patients with quite advanced renal disease where dialysis is imminent, about half of them succumb to cardiovascular diseases and other age-related ailments before they reach a point where they have to be dialysed.

The incidence and prevalence of diabetes and hypertension has been on the rise over the past few decades and will continue to be on an upward trajectory riding on the back of our lifestyle choices. At the same time, better treatments and drugs are available for these ailments so that people with diabetes and hypertension are living longer than before. Cardiovascular diseases, which were once a major cause of morbidity and mortality in these patients have also seen remarkable progress and advances in management over the past few decades. This means that the odds that such patients develop chronic kidney disease in their lifetime have also risen over the past few decades. All of these will inevitably culminate in an epidemic of CKD in the coming decades which if not managed well will put an enormous strain on our infrastructure.

(Dr Vinayak M is Associate Consultant, Department of Nephrology, KIMSHEALTH)