Relationships Between Metabolic Syndrome, Microalbuminuria, and C-Reactive Protein in Turkish Kidney Transplant Recipients

Exploring the nexus: The place of kidney diseases within the cardiovascular-kidney-metabolic syndrome spectrum

Cardiovascular-kidney-metabolic (CKM) syndrome and chronic kidney disease (CKD) are two significant comorbidities affecting a large proportion of the general population with considerable crosstalk. In addition to substantial co-incidence of CKD and CKM syndrome in epidemiological studies, clinical and pre-clinical studies have identified similar pathophysiological pathways leading to both entities. Patients with CKM syndrome are more prone to develop acute kidney injury and CKD, while therapeutic alternatives and their success rates are considerably lower in such patient groups. Nevertheless, the association between CKM syndrome and CKD or ESKD is bidirectional rather than being a cause-effect relationship as patients with CKD are also prone to develop peripheral insulin resistance, high blood pressure, and dyslipidemia. Furthermore, such patients are less likely to receive kidney transplantation in addition to the higher allograft dysfunction risk. We hereby aim to evaluate the association in-between kidney diseases and CKM syndrome, including epidemiological data, pre-clinical studies with pathophysiological pathways, and potential therapeutic perspectives.

Metabolic phenotypes and risk of end-stage kidney disease in patients with type 2 diabetes

Background

Obesity often initiates or coexists with metabolic abnormalities. This study aimed to investigate the pathological characteristics and the independent or mutual relations of obesity and metabolic abnormalities with end-stage kidney disease (ESKD) in patients with type 2 diabetes (T2D) and associated diabetic kidney disease (DKD).

Methods

A total of 495 Chinese patients with T2D and biopsy-confirmed DKD between 2003 and 2020 were enrolled in this retrospective study. The metabolic phenotypes were based on the body weight index (BMI)-based categories (obesity, BMI ≥ 25.0 kg/m²) and metabolic status (metabolically unhealthy status, ≥ 1 criterion National Cholesterol Education Program Adult Treatment Panel III (NCEP/ATP III) excluding waist circumference and hyperglycemia) and were categorized into four types: metabolically healthy non-obesity (MHNO), metabolically healthy obesity (MHO), metabolically unhealthy non-obesity (MUNO), and metabolically unhealthy obesity (MUO). The pathological findings were defined by the Renal Pathology Society classification. Cox proportional hazards models were used to estimate hazard ratios (HRs) for ESKD.

Results

There are 56 (11.3%) MHNO patients, 28 (5.7%) MHO patients, 176 (35.6%) MUNO patients, and 235 (47.5%) MUO patients. The high prevalence of the Kimmelstiel-Wilson nodule and severe mesangial expansion were associated with obesity, whereas severe IFTA was related to metabolically unhealthy status. In the multivariate analysis, the adjusted HR (aHR) was 2.09 [95% confidence interval (CI) 0.99-4.88] in the MHO group, 2.16 (95% CI 1.20-3.88) in the MUNO group, and 2.31 (95% CI 1.27-4.20) in the MUO group compared with the MHNO group. Furthermore, the presence of obesity was insignificantly associated with ESKD compared with non-obese patients (aHR 1.22, 95% CI 0.88-1.68), while the metabolically unhealthy status was significantly associated with ESKD compared to the metabolically healthy status in the multivariate analysis (aHR 1.69, 95% CI 1.10-2.60).

Conclusion

Obesity itself was insignificantly associated with ESKD; however, adding a metabolically unhealthy status to obesity increased the risk for progression to ESKD in T2D and biopsy-proven DKD.

Metabolic syndrome and its components are related to a higher risk for albuminuria and proteinuria: Evidence from a meta-analysis on 10,603,067 subjects from 57 studies

BACKGROUND & AIM

Previous studies have explored the relation of metabolic syndrome (MetS), its components and the risk of albuminuria/proteinuria but their results are inconsistent. Then, we aimed to conduct a meta-analysis in order to resolve these controversies.

METHOD

PubMed and Scopus were systematically searched from their inception to 1 march 2018. Risk estimates and their 95% confidence intervals were extracted and pooled using the random-effects approach.

RESULT

A total of 57 studies, 44 studies on albuminuria and 13 studies on proteinuria, with a total sample size of 10,603,067 participants, were included in this meta-analysis. Overall, MetS was contributed to higher risks of proteinuria (OR = 2.08, 95%CI = 1.85-2.34) and albuminuria (OR = 1.92, 95%CI = 1.71-2.15), independent of diabetes status; although, this relationship was more noticeable in studies that used the WHO definition of MetS and in non-East Asian populations. Also, the relationship between MetS and proteinuria was sex independent, while, for albuminuria was significant only in men. MetS components such as obesity, impaired fasting glucose, elevated blood pressure and hypertriglyceridemia were associated with significant increases in proteinuria and albuminuria risk, while lower HDL-Cholesterol was only linked to greater risk of proteinuria. Moreover, the total impact of MetS on proteinuria was more remarkable than each component of the syndrome and an escalating dose-response association was found between the number of MetS components and albuminuria risk.

CONCLUSION

MetS and its components are potential risk factors for albuminuria and proteinuria.