An investigation of low-protein diets' qualification rates and an analysis of their short-term effects for patients with CKD stages 3-5: a single-center retrospective cohort study from China

BACKGROUND

The feasibility and efficacy of low-protein diets (LPD) treatment in chronic kidney disease (CKD) is controversial. Based on the characteristics of the Chinese diet, we observe the qualification rates and short-term clinical effects of LPD for CKD patients in our center.

METHODS

This is a retrospective cohort study. CKD stages 3-5 patients who were regularly followed up 5 times (over 2 years) and treated with LPD were included. We collected clinical data to observe the changes in LPD qualification rates and divided patients into LPD and non-LPD group according to the average dietary protein intake (DPI) of 5 follow-up time points and compared the changes in primary and secondary outcome measures between the two groups.

RESULTS

We analyzed data from 161 eligible CKD stages 3-5 patients. From baseline to the 5th follow-up time point, the LPD qualification rates of all patients were 11.80%, 35.40%, 47.82%, 53.43% and 54.04%, respectively. For primary outcome measures, the urine protein/creatinine ratio (UPCR) decreased more in the LPD group than in the non-LPD group [Median (interquartile range, IQR) of the difference between the 5th follow-up time point and baseline: 0.19 (- 0.01-0.73) vs. 0.10 (- 0.08-0.27), P < 0.001]. We constructed three classes of mixed linear models (model I, II, III). The UPCR slopes were all negative in the LPD group and positive in the non-LPD group (P < 0.001). Meanwhile, in model I, the estimate glomerular filtration rate(eGFR) decline slope in the LPD group was lower than that in the non-LPD group [slope (standard error): - 1.32 (0.37) vs. - 2.35 (0.33), P = 0.036]. For secondary outcome measures, body mass index (BMI) triglycerides (TG), body weight, and fat free mass (FFM) showed stable statistical differences in the comparison of LPD and non-LPD groups, with greater declines in the former.

CONCLUSION

The results of this study suggest that LPD treatment can reduce UPCR in patients with CKD stages 3-5, and may also delay the decline in eGFR. Meanwhile, it also reduces BMI, TG, body weight, and FFM, thus the need to prevent malnutrition in clinical implementation.

Is E-Version Transition of the Medication Adherence Scale Feasible for CKD Management? A Pilot Study

BACKGROUND

To transfer a paper-version Chinese and Western medication adherence scale for CKD into an electronic scale, and evaluate its validity, internal consistency and clinical implementation, and assess whether the transition is feasible in clinic.

METHODS

We built an e-version Chinese and Western medication adherence scale based on the Wen-JuanXing platform. CKD subjects' responses were applied to test the scale's validity and internal consistency. We retested some of the participants two weeks later randomly. We also tested the clinical application.

RESULTS

Of the 434 recruited patients, 228 responded. In exploratory factor analysis (EFA), the Kaiser-Meyer-Olkin (KMO) measure of sampling adequacy = 0.8 and Bartlett's approx. Chi-Square = 1340.0 (df = 105, p < 0.001). We extracted four common factors which could explain 61.47% of the variance. However, Item 15 "Have you changed a traditional Chinese medicine prescription yourself within the past month?" had factor loading = 0.3 and measure of sampling adequacy (MSA) = 0.5, meaning we could not enter it into the factor analysis. The internal consistency reliability for medication adherence was 0.9, with a Guttman split-half coefficient = 0.5 and a Spearman-Brown coefficient = 0.6. Cronbach's α was 0.9, 0.4 and 0.5 for the knowledge, belief and behavior domains, respectively. The correlation coefficient r of the test-retest reliability was -0.8 and was -0.8, 0.4, -0.3 in the knowledge, belief and behavior domains, respectively. Patients with comorbidities were more likely to respond. We detected no other significant differences in the clinical profiles between respondents and non-respondents.

CONCLUSION

The e-version Chinese and Western medication adherence scales have undesirable construct validity and internal consistency. Thus, caution is needed in transitioning the paper-version scale into an e-version.