Lean-to-fat tissue ratio as a risk factor for cognitive impairment in patients undergoing maintenance hemodialysis

Nutritional Assessments by Bioimpedance Technique in Dialysis Patients

Bioelectrical impedance analysis (BIA) has been extensively applied in nutritional assessments on the general population, and it is recommended in establishing the diagnosis of malnutrition and sarcopenia. The bioimpedance technique has become a promising modality through which to measure the whole-body composition in dialysis patients, where the presence of subclinical volume overload and sarcopenic obesity may be overlooked by assessing body weight alone. In the past two decades, bioimpedance devices have evolved from applying a single frequency to a range of frequencies (bioimpedance spectroscopy, BIS), in which the latter is incorporated with a three-compartment model that allows for the simultaneous measurement of the volume of overhydration, adipose tissue mass (ATM), and lean tissue mass (LTM). However, clinicians should be aware of common potential limitations, such as the adoption of population-specific prediction equations in some BIA devices. Inherent prediction error does exist in the bioimpedance technique, but the extent to which this error becomes clinically significant remains to be determined. Importantly, reduction in LTM has been associated with increased risk of frailty, hospitalization, and mortality in dialysis patients, whereas the prognostic value of ATM remains debatable. Further studies are needed to determine whether modifications of bioimpedance-derived body composition parameters through nutrition intervention can result in clinical benefits.

Decreased Intracellular to Total Body Water Ratio and Depressive Symptoms in Patients with Maintenance Hemodialysis

Objective

Depression is a common psychiatric disorder and related to poor outcomes in patients undergoing maintenance hemodialysis (MHD). Previous studies have reported some associations between sarcopenia and depressive symptoms. Recently, intracellular water (ICW) and total body water (TBW) have been found to reflect muscle function and muscle mass. ICW/TBW ratio is a marker of sarcopenia that is simple to assess. However, the relationship between ICW/TBW ratio and depression has not been explored in MHD patients.

Methods

In our cross-sectional and multi-center study, 3300 adult MHD patients were included from June 1, 2021, to August 30, 2021. Depressive symptoms were evaluated using the Beck Depression Inventory-II (BDI-II). TBW and ICW were measured by Body Composition Monitor (BCM). Multivariable logistic regression, stratified analyses, and interactive analyses were conducted to assess the relationship between ICW/TBW ratio and depression.

Results

About 16.5% of the 3300 MHD patients were found to have depressive symptoms. The prevalence of depression increased with decreasing quartiles of ICW/TBW ratios, and decreased ICW/TBW ratio was independently associated with depression after adjusting for potential confounders. Patients in Quartile 1 of ICW/TBW ratios were more likely to have depressive symptoms (odds ratio 1.55, 95% confidence interval 1.07-2.22; p=0.002) than those in Quartile 4. History of diabetes and education status had interactive roles in the relationship between depression and ICW/TBW ratios (p < 0.05). The association of ICW/TBW ratios and depression existed in patients of both genders and different education levels, but only in non-diabetic patients.

Conclusion

In MHD patients, the decreased ratio of ICW/TBW was independently related to high depression rates.