Association between kidney and cardiac diastolic function in Chinese subjects without overt disease: correlation with ageing and inflammatory markers

Accelerated Kidney Aging in Diabetes Mellitus

With aging, the kidney undergoes inexorable and progressive changes in structural and functional performance. These aging-related alterations are more obvious and serious in diabetes mellitus (DM). Renal accelerated aging under DM conditions is associated with multiple stresses such as accumulation of advanced glycation end products (AGEs), hypertension, oxidative stress, and inflammation. The main hallmarks of cellular senescence in diabetic kidneys include cyclin-dependent kinase inhibitors, telomere shortening, and diabetic nephropathy-associated secretory phenotype. Lysosome-dependent autophagy and antiaging proteins Klotho and Sirt1 play a fundamental role in the accelerated aging of kidneys in DM, among which the autophagy-lysosome system is the convergent mechanism of the multiple antiaging pathways involved in renal aging under DM conditions. Metformin and the inhibitor of sodium-glucose cotransporter 2 are recommended due to their antiaging effects independent of antihyperglycemia, besides angiotensin-converting enzyme inhibitors/angiotensin receptor blockers. Additionally, diet intervention including low protein and low AGEs with antioxidants are suggested for patients with diabetic nephropathy (DN). However, their long-term benefits still need further study. Exploring the interactive relationships among antiaging protein Klotho, Sirt1, and autophagy-lysosome system may provide insight into better satisfying the urgent medical needs of elderly patients with aging-related DN.

Central Blood Pressure Parameters Correlate with Cardiac Structure and Function in Healthy Chinese Individuals without Cardiovascular Disease

PURPOSE

To explore the relationship between central blood pressure (BP) parameters and cardiac structure and function parameters in healthy individuals.

METHODS

Four hundred Chinese participants with no overt cardiovascular disease participated in this study. One hundred and seventy-one participants (42.8%) were male and the mean age was 60 years. Central BP was measured with the SphygmoCor system. Cardiac structure and function were assessed by echocardiography.

RESULTS

We showed a significant association of left atrial volume and left ventricular mass index (LVMI) with brachial and central systolic BP (SBP) and pulse pressure (PP; r = 0.189-0.0.39, p < 0.001). Left ventricular diastolic function and the E/A ratio were significantly associated with brachial and central BP (r = 0.228-0.469, p < 0.001). Multivariate regression analysis revealed that central SBP and PP were independently correlated with LVMI after normalization for age and other confounding variables (sex, body mass index, smoking, and alcohol intake, and the levels of triglycerides, high-density lipoprotein, low-density lipoprotein, creatinine, uric acid, fasting blood glucose, log C-reactive protein, and fibrinogen. However, only central SBP was found to be independently correlated with the E/A ratio.

CONCLUSIONS

Cardiac structure and diastolic function were associated with brachial and central BP. However, after normalization, cardiac structure parameters were independently correlated with central SBP and PP. Diastolic function was the only cardiac function parameter that correlated with central SBP.

The association of serum cathepsin B concentration with age-related cardiovascular-renal subclinical state in a healthy Chinese population

CONTEXT

Cathepsin B (CTSB) is an important enzyme for many physiological and pathological processes, and its activity increases with age. Here, we explored the association between serum CTSB and aging-related subclinical cardiovascular and renal status in a healthy Chinese population.

METHODS

The study included 369 healthy individuals aged 36-87 years. Cardiovascular structure and function were assessed by the left ventricular ejection fraction, the early-diastolic peak flow velocity to late-diastolic peak flow velocity ratio at the mitral leaflet tips, carotid intima-media thickness (IMT), the diameter of the bilateral common carotid artery (D), and blood systolic peak (SPV) and end diastolic velocities, which were measured by M-mode ultrasonography. Serum CTSB, insulin-like growth factor-1 (IGF-1), 1, 25-dihydroxy vitamin D3, and parathyroid hormone (PTH) were measured by enzyme-linked immunosorbent assay.

RESULTS

In men, serum CTSB was significantly related to IMT and IMT/D in the unadjusted model, and these associations were lost after age adjustment. In women, serum CTSB remained significantly associated with serum creatinine (SCr) (p=0.009), estimated glomerular filtration rate (p=0.048) and IMT/D (p=0.017) following full adjustment. PTH was independently associated with SCr. IGF-1 was significantly associated with SPV in women. CTSB was correlated with metabolic and endocrine biomarkers.

CONCLUSION

Serum CTSB was associated with aging-related cardiovascular-renal parameters even in healthy people. Measurement of serum CTSB alone or in combination with metabolic and endocrine biomarkers can provide valuable information for predicting cardiovascular-renal function in healthy people, especially in elderly women.

Influence of chronic kidney disease on cardiac structure and function

Chronic kidney disease (CKD), the presence of kidney dysfunction and/or damage, is a worldwide public health issue. Although CKD is independently associated with various subtypes of cardiovascular diseases, a recent international collaborative meta-analysis demonstrates that CKD is particularly strongly associated with heart failure, suggesting its critical impact on cardiac structure and function. Although numerous studies have investigated the association of CKD and cardiac structure and function, these studies substantially vary regarding source populations and methodology (e.g., measures of CKD and/or parameters of cardiac structure and function), making it difficult to reach universal conclusions. Nevertheless, in this review, we comprehensively examine relevant studies, discuss potential mechanisms linking CKD to alteration of cardiac structure and function, and demonstrate clinical implications as well as potential future research directions. We exclusively focus on studies investigating both CKD measures, kidney function (i.e., glomerular filtration rate [GFR], creatinine clearance, or levels of filtration markers), and kidney damage represented by albuminuria, since current international clinical guidelines of CKD recommend staging CKD and assessing its clinical risk based on both GFR and albuminuria.