Hypothyroidism is a highly prevalent endocrine complication in chronic kidney disease (CKD) patients. A large body of evidence has shown that there is a bidirectional relationship between thyroid dysfunction and kidney disease, yet there are many remaining gaps in knowledge in regards to the clinical management of CKD patients with hypothyroidism, including those receiving hemodialysis and peritoneal dialysis. Given that hypothyroidism has been associated with many deleterious outcomes including a higher risk of (1) mortality, (2) cardiovascular disease, (3) impaired health-related quality of life, and (4) altered body composition in both non-CKD and CKD patients, future research is needed to establish the appropriate screening, diagnosis, and treatment approaches in these populations.

Purpose of review

Chronic kidney disease (CKD) is highly prevalent in elderly patients. There is growing recognition of the importance of attention to dietary protein intake (DPI) in this population given their predisposition to age-related changes in kidney function and coexisting comorbidities (i.e., hypertension). We reviewed the impact of DPI on kidney health and survival and the role of dietary protein management in older CKD patients.

Recent findings

While kidney function parameters including glomerular filtration rate (GFR) and renal plasma flow are slightly lower in elderly patients irrespective of CKD status, the kidneys' ability to compensate for increased DPI by augmentation of GFR is preserved until 80 years of age or less. However, long-term consumption of high DPI in individuals of older age and/or with CKD may contribute to kidney function deterioration over time. Prescription of a plant-dominant low-protein diet of 0.6-0.8 g/kg/day with more than 50% from plant sources or very low protein diets less than 0.45 g/kg/day supplemented with essential amino acids or their keto-analogues may be effective in preserving kidney function in older patients and their younger counterparts, while also monitoring for development of protein-energy wasting (PEW).

Summary

Using tailored precision nutrition approaches in prescribing plant-dominant low DPI that also maintains adequate energy and nitrogen balance may ameliorate kidney function decline while also preventing development of PEW in elderly patients with CKD.

Abstract: BACKGROUND AND AIMS: Low physical activity is common in hemodialysis (HD) patients and is associated with adverse outcomes in this population (poor health-related quality of life, cardiovascular [CV] disease, death). Prior studies show that hypothyroidism is highly prevalent in HD patients, and is associated with worse self-reported physical function. METHOD: In a substudy of the ongoing multi-center NIH THYROID-HD Trial, we examined baseline physical activity scores determined by the Human Activity Profile (HAP), a validated 94-item instrument assessing daily activities across a wide range of energy expenditures, in HD patients with TSH levels in the high-normal (TSH >3–5 mIU/L) and subclinical hypothyroid range (TSH >5–10 mIU/L). The HAP was used to derive the Maximum Activity Score (MAS) and Adjusted Activity Score (AAS), representing greatest and mean estimated energy expenditures, respectively (range 0–94, segmented to low [<52], moderate [54–73] and high [>74] scores). RESULTS: Among 100 HD patients who underwent baseline HAP assessment, the mean ± SD MAS and AAS scores were 48 ± 22 and 23 ± 27,  respectively; median (IQR) MAS and AAS scores were 49 (31–64) and 9 (0–39), respectively (Figure 1). In the overall cohort, 83% had low, 10% moderate and 7% high AAS scores. MAS and AAS scores were significantly lower in patients who had underlying diabetes versus those without diabetes (Table 1). There was also a trend towards lower (worse) MAS and AAS scores among older versus younger patients (≥65 versus >65 years, respectively) and patients with underlying coronary artery disease (CAD) versus those without CAD. In logistic regression analyses, older age (+∆ 1-year increments) was associated with higher likelihood of low MAS scores, and diabetes trended towards a significant association (defined as < median of observed values) (ref: MAS ≥ median): ORs [95% confidence intervals (95% CIs)]: 1.04 (1.01–1.09); P = 0.005 and 2.57 (0.96–6.86); P = 0.06, respectively. Similarly, older age (+∆ 1-year increments) and diabetes were each associated with higher likelihood of low AAS scores (defined as < 52) (ref: moderate-high AAS scores): ORs (95% CIs): 1.06 (1.02–1.11); P = 0.01 and 4.83 (14.6–16.0); P = 0.01, respectively. CONCLUSION: In this substudy of the NIH THYROID-HD Trial, HAP scores in HD patients with high-normal and subclinical hypothyroid range TSH levels were lower than observed in prior historical dialysis cohorts that did not have underlying thyroid dysfunction. Additionally, older age and diabetes were each associated with worse HAP scores. Further research is needed to determine the impact of thyroid hormone replacement on improving physical activity and function in this population, particularly those of elder age and with underlying diabetes.

There is rising interest globally with respect to the health implications of vegetarian or plant-based diets. A growing body of evidence has demonstrated that higher consumption of plant-based foods and the nutrients found in vegetarian and plant-based diets are associated with numerous health benefits, including improved blood pressure, glycemic control, lipid levels, body mass index, and acid-base parameters. Furthermore, there has been increasing recognition that vegetarian and plant-based diets may have potential salutary benefits in preventing the development and progression of chronic kidney disease (CKD). While increasing evidence shows that vegetarian and plant-based diets have nephroprotective effects, there remains some degree of uncertainty about their nutritional adequacy and safety in CKD (with respect to protein-energy wasting, hyperkalemia, etc.). In this review, we focus on the potential roles of and existing data on the efficacy/effectiveness and safety of various vegetarian and plant-based diets in CKD, as well as their practical application in CKD management.

Dialysis has been the dominant treatment regimen in end-stage kidney disease as a means to remove uremic waste products and to maintain electrolyte, acid base, and fluid balance. However, given that dialysis may not always provide a survival benefit nor improved quality of life in certain subpopulations, there is growing recognition of the need for conservative and preservative management as an alternative treatment strategy for advanced chronic kidney disease (CKD). Personalized nutritional management tailored to patients sociodemographics, social needs, psychological status, health literacy level, and preferences is a key component of conservative and preservative care, as well as in the management of patients transitioning from non-dialysis dependent CKD to dialysis. In this review, we discuss the nutritional and metabolic alterations that ensue in CKD; the rationale for low-protein diets in the conservative and preservative management of advanced CKD; the role of plant-based diets in kidney health; emerging data on dietary potassium and sodium intake on CKD outcomes; and the practical implementation of dietary interventions in advanced kidney disease.

Background: Chronic kidney disease (CKD) patients have displayed a paradoxical association between total cholesterol (TC) and mortality, where CKD patients with elevated TC did not display an increased mortality risk. However, this TC-mortality relationship amongst CKD patients requires further study using large databases to assess the impact CKD stage, pharmacologic therapy, and patient population has. Methods: Retrospectively, two cohorts were studied using LIPROVET and NHANES data. Among the cohorts, there were 2,131,536 LIPROVET US veterans examined from 2004-2006 and 39,899 NHANES patients from 1999-2014. We examined the association of TC and statin use with all-cause mortality in patients with eGFR <60 and eGFR ≥60 mL/min/1.73m 2 using Cox Proportional Hazards model. Models were adjusted for demographics, comorbidities, smoking status, alcohol intake, income, education, laboratory measures, and medications. Those with TC≥200 mg/dL not on statin were used as reference. Results: The LIPROVET patients had a mean age of 63±14 and were 81% White and 5% female. LIPROVET patients with TC<200 mg/dL not on statin had a higher mortality risk compared to reference across all levels of adjustment and eGFR. Whereas those on statin, regardless of TC levels, had a lower to null mortality risk in the fully adjusted model. NHANES patients had a mean age 48±19 and were 46% White and 50% male. NHANES patients with TC<200 mg/dL not on statin had a trend of higher to null mortality risk compared to reference across eGFR groups after full adjustment. Those on statin, independent of TC levels, had a significantly lower mortality rate across all eGFR groups. Conclusion: Compared to patients with TC≥200mg/dL not on statin, patients with lower TC without statin had a higher mortality risk, while patients with statin had lower mortality risk regardless of TC level across all eGFR groups. Physicians may consider initiating or continuing statin therapy for CKD patients independent of TC level.

BACKGROUND: Several studies suggest that Asian-American and Native Hawaiian and Other Pacific Islander (NHOPI) racial/ethnic groups have a heightened risk of chronic kidney disease (CKD), but provide limited inference due to the aggregation of these groups into a single racial/ethnic category. We thus examined the association of granularly defined racial/ethnic groups with specific CKD indicators among a diverse group of participants from the National Kidney Foundation of Hawaiis Kidney Early Detection Screening (KEDS) Program. METHODS: Among 1,243 participants enrolled in 19 KEDS screening events over 2006-2009, we examined the association between Asian-American and NHOPI groups and specific CKD indicators, defined as self-reported CKD, microalbuminuria, and macroalbuminuria, using multivariable logistic regression. We then examined associations of race/ethnicity with various CKD risk factors. RESULTS: The most predominant racial/ethnic groups were White (22.0%), Multiracial (18.9%), Japanese (19.2%), Filipino (13.4%), NHOPI (8.4%), and Chinese (4.5%) participants. NHOPI and Chinese participants had a higher risk of microalbuminuria (adjusted ORs [aORs] [95% CIs] 2.48 [1.25-4.91] and 2.37 [1.07-5.27], respectively), while point estimates for all other minority groups suggested higher risk (reference: Whites). NHOPI participants also had a higher risk of macroalbuminuria and self-reported CKD. While most minorities had a higher risk of diabetes and hypertension, NHOPI and Multiracial participants had a higher risk of obesity, whereas the East Asian groups had a lower risk. CONCLUSIONS: In this community-based cohort, compared with Whites, Asian-Americans had a higher risk of early CKD indicators, whereas NHOPIs had a higher risk of more severe CKD indicators. Further studies are needed to elucidate the distinct pathways leading to CKD across diverse racial/ethnic groups in Hawaii.

OBJECTIVE: To examine the relationship between thyroid status and incident kidney dysfunction/chronic kidney disease (CKD) progression. PATIENTS AND METHODS: We examined incident thyroid status, ascertained by serum thyrotropin (TSH) levels measured from January 1, 2007, through December 31, 2018, among 4,152,830 patients from the Optum Labs Data Warehouse, containing deidentified retrospective administrative claims data from a large national health insurance plan and electronic health record data from a nationwide network of provider groups. Associations of thyroid status, categorized as hypothyroidism, euthyroidism, or hyperthyroidism (TSH levels >5.0, 0.5-5.0, and <0.5 mIU/L, respectively), with the composite end point of incident kidney dysfunction in patients without baseline kidney dysfunction and CKD progression in those with baseline CKD were examined using Cox models. RESULTS: Patients with hypothyroidism and hyperthyroidism had higher risk of incident kidney dysfunction/CKD progression in expanded case-mix analyses (reference: euthyroidism): adjusted hazard ratios (aHRs) (95% CIs) were 1.37 (1.34 to 1.40) and 1.42 (1.39 to 1.45), respectively. Incrementally higher TSH levels in the upper reference range and TSH ranges for subclinical, mild overt, and overt hypothyroidism (≥3.0-5.0, >5.0-10.0, >10.0-20.0, and >20.0 mIU/L, respectively) were associated with increasingly higher risk of the composite end point (reference: TSH level, 0.5 to <3.0 mIU/L): aHRs (95% CIs) were 1.10 (1.09 to 1.11), 1.37 (1.34 to 1.40), 1.70 (1.59 to 1.83), and 1.70 (1.50 to 1.93), respectively. Incrementally lower TSH levels in the subclinical (<0.5 mIU/L) and overt (<0.1 mIU/L) hyperthyroid ranges were also associated with the composite end point: aHRs (95% CIs) were 1.44 (1.41 to 1.47) and 1.48 (1.39 to 1.59), respectively. CONCLUSION: In a national cohort, TSH levels in the upper reference range or higher (≥3.0 mIU/L) and below the reference range (<0.5 mIU/L) were associated with incident kidney dysfunction/CKD progression.