Skip to main content

Incidence and outcomes of acute kidney injury in octogenarians in Jordan



Improvements in the health care system, resulted in a greater number of geriatric patients diagnosed with acute kidney injury (AKI). We evaluated the incidence and outcome of AKI in octogenarians, as studies in the Middle-East region are few; moreover, treatment approaches, in addition to medical decisions, may require special consideration for advanced age to improve the outcomes.


At King Abdullah II teaching and referral hospital, we recruited patients aged 80–90 years who were admitted to the medical floor between January 2010 and December 2013. Patients were followed-up for at least 1 year after discharge.850 patients were admitted during the study period. Of these, 135 were excluded from our analysis. The most common admission diagnoses were uncontrolled diabetes mellitus and acute coronary syndrome. AKI occurred in 216 patients (30.2%). Using the acute kidney injury network classification; stage 1, stage 2, and stage 3 disease were present in 59, 17.5, and 23.5% of patients, respectively. Of the 115 patients who died before discharge (16.1%), 87 (75.6%) had developed AKI. Hypertension, the use of angiotensin receptor blockers and non-steroidal anti-inflammatory drugs, heart failure, and exposure to radiologic contrast media were significant risk factors for AKI.


Medical improvements, including the introduction of new medications, medical procedures, and treatment guidelines, lead to a longer lifespan [1]. An aging population may require new approaches for evaluation and treatment, on the other hand identifying risks for AKI which could be specific to older people may help avoid further morbidity and mortality. Studies conducted to evaluate outcomes in geriatric patients tend to treat all cases similarly regardless of the individual’s age. This practice is not necessarily a realistic approach, as we know survival in sexagenarians is different than that in nonagenarians [2, 3].

Aging causes not only functional changes, but also structural and morphological changes at the level of the kidneys, and these may increase the risk for a decline in renal function [4, 5]. With many individuals reaching the age of 80 years or above, extended life expectancy will increase the number of hospitalized geriatric patients and those with acute kidney injury [6, 7].

AKI is common in hospitalized patients, and geriatric patients have an increased risk of AKI because of their age [4, 8], multiple comorbidities, and polypharmacy among other factors [9,10,11,12], with more chance for progression of chronic kidney disease (CKD) post-AKI [13]. AKI can increase mortality and morbidity in geriatric patients regardless of the need for dialysis.

We evaluated the incidence and outcome of AKI in octogenarians in Jordan, as studies in this age group are limited, and the impact of AKI on morbidity, mortality, hospitalization and need for renal replacement therapy (RRT) needs yet to be determined and addressed in an era where the number of octogenarians and even older people are increasing in numbers in our country.

AKIN classification was used to define AKI: (stage 1 is diagnosed with a 1.5-fold increase in creatinine or more than 26.52 μmol/l, stage 2 is diagnosed with a twofold increase in creatinine, and stage 3 is diagnosed with a threefold increase in creatinine or more than 353.6 μmol/l or patient needed dialysis).

We found that risk for AKI is increasing in octogenarians with the following risk factors: hypertension (HTN), congestive heart failure (CHF), use of angiotensin-converting enzyme (ACE) Inhibitors, use of angiotensin receptor blockers (ARBs), use of nonsteroidal anti-inflammatory drugs (NSAIDs), and exposure to contrast media.

Main text


Patient selection and data collection

We retrospectively evaluated all octogenarians admitted to the medical ward of our tertiary referral teaching hospital in northern Jordan between January 2010 and December 2013. All patients had at least one year of follow-up after discharge. The first admission was analyzed if the patient had more than one admission.

Demographic data, including age, gender, comorbidities, the cause of admission, medications, and laboratory data were extracted from patients’ electronic records. Exclusion criteria were: age (< 80 years or ≥ 90 years), advanced CKD with Glomerular Filtration Rate (GFR) less than 30 ml/min in stages 4 and 5, and end stage renal disease (ESRD) patients who are already on chronic dialysis.

AKI was defined using the Acute Kidney Injury Network (AKIN) classification [14], GFR was calculated using modification of diet in renal disease (MDRD) [15], and contrast exposure was defined as intravenous contrast administration within 1 week of AKI onset. Baseline creatinine was defined as the last serum creatinine recorded before admission, as this may reflect a steadier state of kidney function.

Hypertension was defined as the use of at least one antihypertensive drug, or blood pressure > 140/90 mmHg on admission.

The Institutional Research Board of King Abdullah University Hospital approved the study. Because of the retrospective study design, the requirement for patient consent was waived.

Statistical analysis

All analyses were performed using STATA/MP, version 14.0 (StataCorp LLC, College Station, TX, US). Data was described using means and standard deviation (± SD) for continuous variables and percentages for categorical variables. Patients were divided into two groups: patients with and patients without AKI. The differences between the two groups in the means of continuous variables were tested using independent t tests. Pearson’s Chi squared test was used to compare the incidence rates of AKI according to the distribution of demographic, clinical, and relevant patient characteristics between the two groups. Cox proportional hazard model was used to assess the effect of different covariates on outcomes.


Patient characteristics

Of the 850 octogenarians admitted during the study period, 135 were excluded due to advanced CKD or a dialysis requirement. In the 715 remaining patients, the mean age was 85.9 years, 16.1% were diabetic, 17.5% had hypertension (HTN), and 2.8% took nonsteroidal anti-inflammatory medications (NSAIDs). Baseline characteristics are presented in Table 1.

Table 1 Baseline characteristics of octogenarians

The most common causes of admission were: uncontrolled diabetes mellitus (DM) with patients’ HbA1C more than 8% or random blood sugar on admission > 300 mg/dl (18.3%), acute coronary syndrome (12.8%), and other cardiac causes (6.9%) including heart failure and arrhythmias. Central nervous system disease most frequently manifested as stroke (ischemic, 5.2%; hemorrhagic, 1.9%). Infection was the cause of admission in 17.0%, most commonly urinary tract infection (6.9%) and pneumonia (2.3%). Injury secondary to a fall accounted for 5.5% of admissions.

Incidence and outcome of AKI

AKI was diagnosed in 216 patients (30.2%). Of these cases, 59% had stage 1 disease while stage 2 and stage 3 disease were present in 17.5% and 23.5%, respectively. One can think that the chance of having smaller changes in creatinine as in stage 1 is far more common than having bigger jumps in serum creatinine as in stages 2 and 3, which make it more sensible to find a larger number of patients in stage 1 than others.

A comparison of baseline characteristics in both groups (Table 2) revealed that patients with AKI were more likely to have HTN (P = 0.001) and congestive heart failure (CHF, P = 0.003), and to take either an angiotensin receptor blocker (ARB, P = 0.04) or NSAID (P = 0.003). Patients with AKI had been more frequently exposed to radiologic contrast media (P = 0.001). All the previous factors that we found are risks for AKI in the general population too, not only in octogenarians; advanced age patients may still have the tendency to have more of these risk factors together apart from age itself that has its obvious effect on kidney aging and loss of function [16, 17].

Table 2 Baseline characteristics of octogenarians based on acute kidney injury status

A Cox proportional hazard model demonstrated that hypertension increased the risk of AKI by 1.6 times, while NSAID use and contrast exposure increased this risk by 1.3 and 1.4 times, respectively (Table 3). The length of in-hospital stay was longer in the AKI group than in the non-AKI group: 8.9 days (± 11.8) vs. 3.5 days (± 3.6), respectively (P = 0.0001).

Table 3 Cox proportional hazard ratio

By the time of discharge, the mean serum creatinine was 198.5 μmol/l (± 145) in patients with AKI and 106.4 μmol/l (± 94.6) in those without (P = 0.0001). Of the 115 patients who died before discharge (16.1%), 87 (75.6%) had developed AKI. In patients with AKI, mortality was significantly associated with HTN (P = 0.001), CHF (P = 0.03), and exposure to radiologic contrast media (P = 0.005). In summary: age, HTN, NSAID use, ARB or ACE inhibitor use, and exposure to contrast media will increase the chance to get AKI, with longer hospital stays and higher mortality especially in patients with HTN, CHF and contrast media exposure.


Mortality in geriatric patients is significantly associated with cardiovascular disease, and this association is even stronger in the presence of AKI [18, 19]. The incidence of AKI differs according to the definition adopted {The kidney disease improving global outcomes (KDIGO), (AKIN), risk, injury, failure, loss of kidney function, and end-stage kidney disease (RIFLE)} and according to the CKD stage in geriatric patients [14, 20]. Our sub-stratification analysis of the incidence of each stage of AKI revealed that patients with stage 1 disease (with > 0.3 mg/dl increase in creatinine) were the majority. This finding is consistent with the finding of a large population-based Chinese study that also used the AKIN criteria [21].

We found it interesting that only approximately 16 and 17% of patients had DM or HTN, respectively. We hypothesize that this is related to high cardiovascular mortality in patients with DM, which preclude the majority with this diagnosis from reaching their 80’s [22, 23], especially given the comorbidities and frailty that come with age [24, 25]. One issue to consider is the increased risk of injury due to falls in this age group. This risk is multifactorial and may occur in the presence of subtle cognitive deterioration [26], muscle weakness [27], and osteoporosis [28]. The injury would be the beginning of a sequence of complications, deterioration of function, and may require more hospitalization.

We found that risk factors for AKI include exposure to nephrotoxic agents like: NSAIDS, ACE inhibitors, ARBs, [29] and contrast media [30]. Patients with AKI had higher overall mortality (75.6% for AKI group vs. 24.4% for non-AKI group) and longer hospital stays (8.9 vs. 3.5 days) in patients without AKI. It is worth mentioning that the use of ACE inhibitors and ARB were used not only to treat HTN but also to treat those patients with coronary artery disease and CHF. Previous studies have shown that rehospitalization is also more common in octogenarians and is associated with high medical costs and mortality [24, 31]. Most of our patients, as compared to patients in other studies, had CHF or HTN [32] or were exposed to contrast media [30].

In severe AKI, the need for renal replacement therapy, including dialysis, is higher and may increase in-hospital stay, mortality, and the chance of having CKD. A significant number of affected patients may require chronic dialysis [33]. In our study, 85 patients with AKI (39.5%) needed dialysis, mainly because of hyperkalemia and pulmonary edema. Forty-two patients on dialysis (49.4%) died before discharge. The mean serum creatinine at discharge in the dialysis group was 379.1 μmol/l (± 172.6) vs. 98.9 μmol/l (± 46.9) in those that did not receive dialysis. Unfortunately, we could not follow most of the discharged dialysis patients as they were seen at different hospitals and different dialysis units.

In conclusion, prevention of AKI and early detection with reversal of cause, addressing complications and determining the need for RRT in octogenarians will improve overall survival and decrease associated morbidity in this patient population.


Our study was a single-center study which is the main limitation, due to study design; the cause of AKI was difficult to identify, as well as the nutritional status data, which might have a role in serum creatinine level interpretation. Although it included a fair number of patients, we may need to cooperate with our colleagues in other areas of Jordan to have more representative data about the outcomes of octogenarians nationally and facilitate the improvement of our health care system.



acute kidney injury


acute kidney injury network


chronic kidney disease


renal replacement therapy




diabetes mellitus


congestive heart failure


angiotensin converting enzyme


angiotensin receptor blocker


nonsteroidal anti-inflammatory drugs


glomerular filtration rate


end stage renal disease


modification of diet in renal disease


kidney disease improving global outcomes


risk injury failure loss of kidney function and end stage kidney disease


  1. Manton KG, Vaupel JW. Survival after the age of 80 in the United States, Sweden, France, England, and Japan. N Engl J Med. 1995;333:1232–5.

    Article  CAS  PubMed  Google Scholar 

  2. Randall GK, Martin P, Bishop AJ, Poon LW, Johnson MA. Age differences and changes in resources essential to aging well: a comparison of sexagenarians, octogenarians, and centenarians. Curr Gerontol Geriatr Res. 2011;2011:357896.

    Article  PubMed  PubMed Central  Google Scholar 

  3. Santoni G, Angleman S, Welmer AK, Mangialasche F, Marengoni A, Fratiglioni L. Age-related variation in health status after age 60. PLoS ONE. 2015;10:e0120077.

    Article  PubMed  PubMed Central  Google Scholar 

  4. Glassock RJ, Rule AD. Aging and the kidneys: anatomy, physiology and consequences for defining chronic kidney disease. Nephron. 2016;134:25–9.

    Article  PubMed  Google Scholar 

  5. Glassock RJ, Rule AD. The implications of anatomical and functional changes of the aging kidney: with an emphasis on the glomeruli. Kidney Int. 2012;82:270–7.

    Article  PubMed  PubMed Central  Google Scholar 

  6. Chertow GM, Burdick E, Honour M, Bonventre JV, Bates DW. Acute kidney injury, mortality, length of stay, and costs in hospitalized patients. J Am Soc Nephrol. 2005;16:3365–70.

    Article  PubMed  Google Scholar 

  7. Xue JL, Daniels F, Star RA, Kimmel PL, Eggers PW, Molitoris BA, et al. Incidence and mortality of acute renal failure in Medicare beneficiaries, 1992 to 2001. J Am Soc Nephrol. 2006;17:1135–42.

    Article  PubMed  Google Scholar 

  8. Musso CG, Oreopoulos DG. Aging and physiological changes of the kidneys including changes in glomerular filtration rate. Nephron Physiol. 2011;119(Suppl 1):p1–5.

    Article  CAS  PubMed  Google Scholar 

  9. Gong Y, Zhang F, Ding F, Gu Y. Elderly patients with acute kidney injury (AKI): clinical features and risk factors for mortality. Arch Gerontol Geriatr. 2012;54:e47–51.

    Article  PubMed  Google Scholar 

  10. Turgutalp K, Bardak S, Horoz M, Helvaci I, Demir S, Kiykim AA. Clinical outcomes of acute kidney injury developing outside the hospital in elderly. Int Urol Nephrol. 2017;49:113–21.

    Article  CAS  PubMed  Google Scholar 

  11. Ge S, Nie S, Liu Z, Chen C, Zha Y, Qian J, et al. Epidemiology and outcomes of acute kidney injury in elderly chinese patients: a subgroup analysis from the EACH study. BMC Nephrol. 2016;17:136.

    Article  PubMed  PubMed Central  Google Scholar 

  12. Chao CT, Tsai HB, Wu CY, Lin YF, Hsu NC, Chen JS, et al. Cumulative cardiovascular polypharmacy is associated with the risk of acute kidney injury in elderly patients. Medicine. 2015;94:e1251.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  13. Himmelfarb J. Acute kidney injury in the elderly: problems and prospects. Semin Nephrol. 2009;29:658–64.

    Article  PubMed  Google Scholar 

  14. Zeng X, McMahon GM, Brunelli SM, Bates DW, Waikar SS. Incidence, outcomes, and comparisons across definitions of AKI in hospitalized individuals. Clin J Am Soc Nephrol. 2014;9:12–20.

    Article  CAS  PubMed  Google Scholar 

  15. Michels WM, Grootendorst DC, Verduijn M, Elliott EG, Dekker FW, Krediet RT. Performance of the Cockcroft-Gault, MDRD, and new CKD-EPI formulas in relation to GFR, age, and body size. Clin J Am Soc Nephrol. 2010;5:1003–9.

    Article  PubMed  PubMed Central  Google Scholar 

  16. Liu JQ, Cai GY, Liang S, Wang WL, Wang SY, Zhu FL, et al. Characteristics of and risk factors for death in elderly patients with acute kidney injury: a multicentre retrospective study in China. Postgrad Med J. 2018.

    PubMed Central  Google Scholar 

  17. Chao CT, Wang J, Wu HY, Huang JW, Chien KL. Age modifies the risk factor profiles for acute kidney injury among recently diagnosed type 2 diabetic patients: a population-based study. Geroscience. 2018.

    PubMed  Google Scholar 

  18. Ignacak E, Wyrwicz-Zielinska G, Krzysztonek-Weber I, Sulowicz W. Risk factors of death occurrence in patients with acute kidney injury in the course of severe cardio-vascular complications. Przegl Lek. 2016;73:78–82.

    PubMed  Google Scholar 

  19. Ried M, Puehler T, Haneya A, Schmid C, Diez C. Acute kidney injury in septua-and octogenarians after cardiac surgery. BMC Cardiovasc Disord. 2011;11:52.

    Article  PubMed  PubMed Central  Google Scholar 

  20. Del Giudice A, Aucella F. Acute renal failure in the elderly: epidemiology and clinical features. J Nephrol. 2012;25(Suppl 19):S48–57.

    Article  PubMed  Google Scholar 

  21. Wei Q, Liu H, Tu Y, Tang RN, Wang YL, Pan MM, et al. The characteristics and mortality risk factors for acute kidney injury in different age groups in China—a cross sectional study. Ren Fail. 2016;38:1413–7.

    Article  CAS  PubMed  Google Scholar 

  22. Hirakawa Y, Ninomiya T, Kiyohara Y, Murakami Y, Saitoh S, Nakagawa H, et al. Age-specific impact of diabetes mellitus on the risk of cardiovascular mortality: an overview from the evidence for Cardiovascular Prevention from Observational Cohorts in the Japan Research Group (EPOCH-JAPAN). J Epidemiol. 2017;27:123–9.

    Article  PubMed  PubMed Central  Google Scholar 

  23. Huang ES, Laiteerapong N, Liu JY, John PM, Moffet HH, Karter AJ. Rates of complications and mortality in older patients with diabetes mellitus: the diabetes and aging study. JAMA Intern Med. 2014;174:251–8.

    Article  PubMed  PubMed Central  Google Scholar 

  24. Medcalf JF, Davies C, Hollinshead J, Matthews B, O’Donoghue D. Incidence, care quality and outcomes of patients with acute kidney injury in admitted hospital care. QJM. 2016;109:777–83.

    Article  CAS  PubMed  Google Scholar 

  25. Baek SH, Lee SW, Kim SW, Ahn SY, Yu MY, Kim KI, et al. Frailty as a predictor of acute kidney injury in hospitalized elderly patients: a single center retrospective cohort study. PLoS ONE. 2016;11:e0156444.

    Article  PubMed  PubMed Central  Google Scholar 

  26. Gleason CE, Gangnon RE, Fischer BL, Mahoney JE. Increased risk for falling associated with subtle cognitive impairment: secondary analysis of a randomized clinical trial. Demen Geriatr Cogn Disord. 2009;27:557–63.

    Article  Google Scholar 

  27. Hernandez ME, Goldberg A, Alexander NB. Decreased muscle strength relates to self-reported stooping, crouching, or kneeling difficulty in older adults. Phys Ther. 2010;90:67–74.

    Article  PubMed  PubMed Central  Google Scholar 

  28. Schoufour JD, Echteld MA, Bastiaanse LP, Evenhuis HM. The use of a frailty index to predict adverse health outcomes (falls, fractures, hospitalization, medication use, comorbid conditions) in people with intellectual disabilities. Res Dev Disabil. 2015;38:39–47.

    Article  PubMed  Google Scholar 

  29. Kate RJ, Perez RM, Mazumdar D, Pasupathy KS, Nilakantan V. Prediction and detection models for acute kidney injury in hospitalized older adults. BMC Med Inform Decis Making. 2016;16:39.

    Article  Google Scholar 

  30. Kooiman J, Seth M, Nallamothu BK, Heung M, Humes D, Gurm HS. Association between acute kidney injury and in-hospital mortality in patients undergoing percutaneous coronary interventions. Circ Cardiovasc Interv. 2015;8:e002212.

    Article  PubMed  Google Scholar 

  31. Turgutalp K, Bardak S, Horoz M, Helvaci I, Demir S, Kiykim AA. Clinical outcomes of acute kidney injury developing outside the hospital in elderly. Int Urol Nephrol. 2016.

    Google Scholar 

  32. Tessier DM, Meneilly GS, Moleski L, Trottier L, Lanthier L. Influence of blood pressure and other clinical variables on long-term mortality in a cohort of elderly subjects with type 2 diabetes. Can J Diabetes. 2016;40:12–6.

    Article  PubMed  Google Scholar 

  33. Gautam SC, Brooks CH, Balogun RA, Xin W, Ma JZ, Abdel-Rahman EM. Predictors and outcomes of post-hospitalization dialysis dependent acute kidney injury. Nephron. 2015;131:185–90.

    Article  CAS  PubMed  Google Scholar 

Download references

Authors’ contributions

AO and SA conceived and designed the study, collected data, performed analysis and interpreted the results, performed the literature search, and wrote the manuscript. Both authors read and approved the final manuscript.


Not applicable.

Competing interests

The authors declare that they have no competing interests.

Availability of data and materials

Data is available from the corresponding author upon reasonable request.

Consent for publication

Not applicable.

Ethics approval and consent to participate

The Institutional Research Board of King Abdullah University Hospital approved the study. Because of the retrospective study design, the requirement for patient consent was waived.


This research was funded by Jordan University of Science and Technology/Deanship of Research; the sponsor has no role in study design, methodology, collecting and analyzing data, or writing the manuscript.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Ashraf O. Oweis.

Rights and permissions

Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Oweis, A.O., Alshelleh, S.A. Incidence and outcomes of acute kidney injury in octogenarians in Jordan. BMC Res Notes 11, 279 (2018).

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: