The hidden epidemic: Worldwide, over 850 million people suffer from kidney diseases

Kidney diseases have so far been underestimated in many respects: most people are not aware of their impaired kidney function. In general, kidney diseases are “silent diseases”, most often there are no apparent early symptoms. Many people with kidney diseases are not aware that they have been living with higher risks of cardiovascular diseases, infections, hospitalizations, and of course kidney failure which requires dialysis or transplantation.

Kidney diseases have so far been underestimated in many respects: most people are not aware of their impaired kidney function. In general, kidney diseases are “silent diseases”, most often there are no apparent early symptoms. Many people with kidney diseases are not aware that they have been living with higher risks of cardiovascular diseases, infections, hospitalizations, and of course kidney failure which requires dialysis or transplantation.

Kidney diseases to date have not had a major role in most health promotion and public awareness campaigns. This, however, is completely unjustified. We estimate that over 850 million people worldwide have some form of kidney disease, which is roughly double the number of people who live with diabetes (422 million, [1]) and 20 times more than the prevalence of cancer worldwide (42 million [2]) or people living with AIDS/HIV (36.7 million [3]). Thus, kidney diseases are one of the most common diseases worldwide, but the public is unaware of the extent of this health issue. “It is high time to put the global spread of kidney diseases into focus”, explain Professor David Harris, current president of the International Society of Nephrology and Professor Adeera Levin, Past-President of the ISN.

Chronic kidney diseases (defined as abnormalities of kidney structure or function that are persistent for greater than 3 months) make up the majority of current estimates of kidney diseases; the prevalence of chronic kidney diseases worldwide is 10.4% among men and 11.8% among women [4]. Those requiring dialysis or transplantation are between 5.3 and 10.5 million people, although there are many who do not receive these treatments due to lack of resources or financial barriers. Acute kidney injury (AKI), experienced by 13.3 million patients each year, may resolve or lead to chronic kidney diseases or kidney failure in the future. “Using all these sources of data, and existing estimates of acute and chronic kidney diseases, we estimate approximately 850 million kidney patients …a number which surely signifies an 'epidemic' worldwide”, says Levin.

However, it is not only the number, which is dramatic, but also the outcome: “Even, if many patients with impaired kidney function do not feel ill over a long period of time, they are at a particularly high risk of many other health outcomes due to this condition”, explains Professor Carmine Zoccali, president of the European Renal Association – European Dialysis and Transplant Association (ERA-EDTA). As he points out, the average age standardized mortality rate due to low kidney function (GFR) is 21 deaths per 100,000 [4]. In particular, the cardiovascular death toll from chronic kidney diseases is huge: In 2013, there were 1.2 million cardiovascular deaths attributed to kidney diseases [5]. “The death rate among people with kidney diseases is incredibly high! AIDS, for example, accounts for “only” 1.9 deaths per 100,000 [6] – but think about all the campaigning with celebrities and the resulting recognition of HIV as a priority health issue. There is only little active campaigning on behalf of people with kidney diseases, even though the number of people who die from kidney deterioration is 11 times higher.”

“It is time for constructive change in kidney care policy”, confirms Professor Mark D. Okusa, president of the American Society of Nephrology (ASN). “The number of people with kidney diseases is alarmingly high, but the public is not aware of this reality. These patients have outcomes and kidney diseases impose a heavy financial burden on healthcare budgets, as the annual cost per patient for hemodialysis (HD) are, for example, US$ 88,195 in the USA [8], up to US$ 58,812 in Germany, US$ 83,616 in Belgium or US$ 70,928 in France [9].

ASN (https://www.asn-online.org), ERA-EDTA (http://web.era-edta.org) and ISN (https://www.theisn.org ) collaboratively aim to raise worldwide awareness of kidney diseases and to improve prevention efforts. The joint aim of all three associations is to reduce the burden of kidney disease globally and improve awareness. Communicating openly about the current burden of the kidney diseases worldwide is the first step.

References
[1] http://www.who.int/news-room/fact-sheets/detail/diabetes
[2] https://ourworldindata.org/cancer
[3] http://www.who.int/gho/hiv/en/
[4] GBD 2013 Mortality and Causes of Death Collaborators. Global, regional, and national age-sex specific all-cause and cause-specific mortality for 240 causes of death, 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013. Lancet. 2015 Jan 10;385(9963):117-71. 
[5] GBD 2015 Mortality and Causes of Death Collaborators. Global, regional, and national life expectancy, all-cause mortality, and cause-specific mortality for 249 causes of death, 1980-2015: a systematic analysis for the Global Burden of Disease Study 2015. Lancet. 2016 Oct 8;388(10053):1459-1544.
[6] Age-Adjusted Mortality Rate for HIV Disease – https://www.kff.org/hivaids/state-indicator/age-adjusted-hiv-mortality-rate/?currentTimeframe=0&sortModel=%7B%22colId%22:%22Location%22,%22sort%22:%22asc%22%7D
[7] Mills et al. Kidney International 2015; 88: 950–957
[8] United States Renal Data System. 2017 USRDS annual data report: Epidemiology of kidney disease in the United States. National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 2017.
[9] Vanholder R et al. J Am Soc Nephrol 2012;23(8):1291-8