Clinical outcomes among patients with chronic kidney disease hospitalized with diabetic foot disorders: A nationwide retrospective study

Chronic Kidney Disease and Charcot Neuro-Osteoarthropathy of Foot in Diabetes

INTRODUCTION

Charcot neuro-osteoarthropathy (CNO) occurs late in diabetes and may cause fracture, deformity, and higher mortality. Diabetic kidney disease (DKD) affects bone metabolism and contributes to mortality. However, there is no data on prevalence of CNO and its outcomes with coexisting DKD (or chronic kidney disease [CKD]).

METHODS

To ascertain the prevalence of CKD (pick CKD or DKD) among patients with CNO and delineate the remission of active CNO and subsequent lower extremity amputation and all-cause mortality during prospective follow-up. Consecutive patients with diabetic CNO (active or inactive) were enrolled and subsequently divided into those with and without CKD (pick CKD or DKD) (Group A and Group B, respectively). A preestablished timeframe of 36 weeks was utilized to evaluate the remission proportion of active CNO.

RESULTS

A total of 493 CNO patients were observed and 449 subjects (150 patients had active CNO) were further evaluated. The overall prevalence of diabetic nephropathy (DKD or CKD?) CNO was 43.7%. The proportion of patients achieving remission was significantly lower in Group A compared to Group B (OR 0.468, CI [0.239-0.934], P = .025), however, the median time for achieving remission was similar between the 2 groups (14 weeks vs 16 weeks, P = .885). Overall, all-cause mortality was notably higher Group A compared to Group B (OR 2.23, 95% CI [1.474-3.368]) over a median follow-up of 4 years. No significant differences were observed in rates of diabetic foot ulcers (58.2% vs 54.9%; P = .584) and amputations (17.4% vs 15.12%; P = .889) between Group A and Group B.

CONCLUSION

Patients of CNO with coexisting CKD have poor prognosis both in terms of likelihood of active CNO remission and higher mortality.

Albuminuric diabetic kidney disease predicts foot ulcers in type 2 diabetes

Diabetic Foot Ulcers (DFU) are feared among individuals with diabetic kidney disease (DKD), but it is unclear whether they are more frequent, especially in normoalbuminuric DKD. Five hundred and twenty patients admitted in our diabetology ward from 2007 to 2017 were followed up during 54 ± 26 months. New DFUs were registered, and their relationship with the initial renal status was analyzed by LogRank and multivariate Cox regression analysis. The 520 subjects were mainly men (57.9 %), 62 ± 9 years old, with a duration of diabetes of 14 ± 10 years, HbA1c: 8.7 ± 1.8 % (72 ± 19 mmol/mol), and complications: 33.7 % macroangiopathies, 22.1 % previous foot ulcers, 44.8 % DKD, 26.9 % retinopathies. Fifty-seven new DFU occurred, mainly in subjects with DKD. DKD was related to later DFU (HR: 1.79; 95%CI: 1.05-3.07), this relationship stayed significant adjusted for age, gender, and a history of previous DFU (HR: 3.61; 95%CI: 2.11-6.18), and further adjusted for the duration of diabetes, HbA1c, BMI, arterial hypertension, and dyslipidemia. Among the 233 subjects with DKD, 129 (55.3 %) had an isolated AER > 30 mg/24H, 41 (17.6 %) had an isolated eGFR<60 mL/min/1.73 m², and 63 (27.0 %) cumulated both abnormalities. By Cox regression analysis adjusted for age and gender, albuminuric DKDs were related to later DFU: with eGFR≥60: HR: 1.91; 95%CI: 1.02-3.59, with eGFR<60: HR: 2.53; 95%CI: 1.25-5.10, whereas normoalbuminuric DKD was not: HR: 1.04; 95%CI: 0.35-3.07, despite similar rates of neuropathies, peripheral arterial diseases, and retinopathies. In people with type 2 diabetes, albuminuric DKD was associated with two to three folds increased risk of DFUs, whereas normoalbuminuric DKD was not.

[Clinical Characteristics and Prognosis of Diabetic Foot Ulcers Patients of Different Renal Function Statuses]

Objective

To explore the clinical characteristics and the prognosis of diabetic foot ulcers (DFU) inpatients of different renal function statuses.

Methods

A retrospective analysis of 962 inpatients with DFU was conducted. The patients were divided into three groups according to their renal function statuses, and the clinical characteristics of the three groups were compared to identify differences. In addition, the patients were followed up in outpatient clinics or by telephone and their prognostic status and risk factors for death were analyzed.

Results

Analysis of the clinical characteristics showed that, compared with diabetic patients with normal renal function or mild renal function impairment, diabetic patients with moderate and severe renal function impairment had a longer course of disease ( P<0.001). Patients with foot ulcers of Wagner grade 4 predominates the moderate and severe renal function impairment groups ( P<0.05). Patients in the moderate and severe renal function impairment groups had a relatively higher proportion of comorbidities, including hypertension, coronary heart disease, and peripheral arterial disease ( P<0.05). These patients had relatively lower levels of glycosylated hemoglobin and hemoglobin (all P<0.05) and relatively higher levels of neutrophil ratio and procalcitonin (all P<0.05). Of the two groups, patients in the moderate renal function impairment group were older ( P<0.001) and had lower ankle-brachial index ( P<0.001). The severe renal function impairment group had a higher proportion of patients with foot ulcers of Wagner grades 3 and 5 (all P<0.05). For the purpose of conducting prognostic analysis, 748 patients were followed up in outpatient clinics or by telephone for a median length of 41 months. Among them, 239 died. The all-cause mortality was 31.9%, and the mortality in the three groups was 25.8%, 46.2% ( P<0.001), and 59.4% ( P<0.001), respectively. The survival rate of patients in the moderate and severe renal function impairment groups was significantly lower than those in the normal renal function and mild renal function impairment groups ( P<0.001). Univariate Cox regression analysis showed that age, concomitant coronary heart disease and peripheral arterial disease, degree of renal function impairment, and foot ulcers of Wagner grade 4 and 5 were associated with all-cause deaths. Furthermore, multivariate Cox regression analysis showed that moderate and severe renal function impairment was an independent risk factor for all-cause deaths in DFU patients ( P<0.001).

Conclusions

As renal function impairment worsens, patients with DFU present clinical characteristics of greater complexity, higher risks of cardiovascular events, and higher mortality. It is essential to prevent kidney damage and foot ulcers, to pay attention to the cardiovascular risks of DFU patients with moderate and severe renal function impairment, and to reduce mortality.

The association between estimated glomerular filtration rate and prognosis in patients with diabetic foot osteomyelitis

We aimed to explore the association between estimated glomerular filtration rate (eGFR) and prognosis in patients with diabetic foot osteomyelitis (DFO). Three hundred twenty‐one DFO inpatients were enrolled and classified into four groups according to the eGFRs as follows: normal (≥90), mildly reduced (60‐89), moderately reduced (30‐59) and severely reduced (<30). These patients were followed‐up for 6 months to observe the outcomes, including ulcer healing and amputation. The associations between eGFR and the outcomes were analysed by univariate and multivariate logistic regression models. Compared with patients with normal eGFR, patients with severely reduced eGFR group had higher risk of healing failure (OR = 4.72, 95% CI: 1.44‐15.48), total amputation (OR = 4.50, 95% CI: 1.18‐17.13) and minor amputation (OR = 4.05, 95% CI: (1.04‐15.87). Severely reduced eGFR in patients with DFO was an independent predictor for amputation and healing failure.

Re-understanding and focusing on normoalbuminuric diabetic kidney disease

Diabetes mellitus (DM) has grown up to be an important issue of global public health because of its high incidence rate. About 25% of DM patients can develop diabetic foot/ulcers (DF/DFU). Diabetic kidney disease (DKD) is the main cause of end-stage kidney disease (ESKD). DF/DFU and DKD are serious complications of DM. Therefore, early diagnosis and timely prevention and treatment of DF/DFU and DKD are essential for the progress of DM. The clinical diagnosis and staging of DKD are mostly based on the urinary albumin excretion rate (UAER) and EGFR. However, clinically, DKD patients show normoalbuminuric diabetic kidney disease (NADKD) instead of clinical proteinuria. The old NADKD concept is no longer suitable and should be updated accordingly with the redefinition of normal proteinuria by NKF/FDA. Based on the relevant guidelines of DM and CKD and combined with the current situation of clinical research, the review described NADKD from the aspects of epidemiology, pathological mechanism, clinical characteristics, biomarkers, disease diagnosis, and the relationship with DF/DFU to arouse the new understanding of NADKD in the medical profession and pay attention to it.