Intradialytic serum phosphate variations are associated with low PTH levels.

BACKGROUND: Numerous studies have explored the role of kidney replacement therapy (KRT) in phosphorus (P) control among prevalent hemodialysis (HD) patients. However, whether the reduction of P achieved during KRT affects parathyroid hormone (PTH) levels is still a matter of debate. METHODS: We conducted a retrospective observational study on the prevalent HD population at the Division of Nephrology, University Hospital of Verona, from January to December 2022. We Included clinically stable adult patients undergoing HD for over 6 months, with multiple recorded visits during the follow-up. Demographic, clinical, laboratory, and medication data were collected. Time-varying variables were updated at each study visit. The primary outcome of interest was PTH levels. The absolute intra-HD change in P (intra-HD ∆P), defined as the difference between pre- and post-HD P levels, served as the main exposure. Multivariable adjusted linear mixed models were used to investigate the relationship between intra-HD ∆P and PTH levels. RESULTS: A total of 211 patients contributed to 904 study visits. A significant and positive relationship was observed between intra-HD ∆P and pre-HD P (ß = 0.76, 95% CI 0.75, 0.78, p < 0.001) and urea reduction ratio (ß = 0.38, 95% CI 0.35, 0.41; p < 0.001). An increase in intra-HD ∆P was significantly and independently associated with low PTH levels (ß = - 0.16, 95% CI - 0.30, -0.03; p = 0.020). CONCLUSIONS: The extent of intra-HD P reduction significantly correlates with low PTH levels. Strategies focused on optimizing or enhancing depurative efficiency in KRT can exert a substantial impact on managing positive phosphorus balance and secondary hyperparathyroidism. The assessment of intra-HD P reduction may play a pivotal role in the management and follow-up of secondary hyperparathyroidism in HD patients.

Nutritional Aspects in Diabetic CKD Patients on Tertiary Care.

Background and objectives: Diabetes is largely prevalent in the chronic kidney disease (CKD) population. Both conditions have metabolic and nutritional abnormalities that affect body composition and the presence of diabetes makes the dietary management of CKD patients more difficult. The aim of this study was to assess peculiar nutritional and functional aspects of diabetic patients in an adult/elderly CKD population, and their predictive significance. Materials and methods: This prospective cohort study included 144 out-patients aged >55 years, affected by stage 3b-4 CKD, on tertiary care clinic; 48 (40 males) were type 2 diabetics and 96 (80 males) were nondiabetics. The two groups have similar age, gender, and residual renal function (30 ± 9 vs. 31 ± 11 mL/min×1.73). All patients underwent a comprehensive nutritional and functional assessment and were followed for 31 ± 14 months. Results: Diabetic CKD patients showed higher waist circumference and fat body mass, lower muscle mass, and lower number of steps per day and average daily METs. Meanwhile, resting energy expenditure (REE), as assessed by indirect calorimetry, and dietary energy intake were similar as well as hand-grip and 6 min walking test. Diabetic patients did not show a greater risk for all-cause mortality and renal death with respect to nondiabetics. Middle arm muscle circumference, phase angle, serum cholesterol, and serum albumin were negatively related to the risk of mortality and renal death after adjustment for eGFR. Conclusions: CKD diabetic patients differed from nondiabetics for a greater fat mass, lower muscle mass, and lower physical activity levels. This occurred at the same REE and dietary energy intake. The outcome of diabetic or nondiabetic CKD patients on tertiary care management was similar in terms of risk for mortality or renal death. Given the same residual renal function, low levels of muscle mass, phase angle, serum albumin, and cholesterol were predictive of poor outcome. Overall, a malnutrition phenotype represents a major predictor of poor outcome in diabetic and nondiabetic CKD patients.

Prevalence and Correlates of Sarcopenia among Elderly CKD Outpatients on Tertiary Care.

BACKGROUND: Sarcopenia is a widespread concern in chronic kidney disease (CKD) as well in elderly patients and is one of the main reasons why low-protein diets for this population are controversial. The aim of this study was to assess the prevalence and correlates of sarcopenia among elderly male patients affected by CKD followed up in an outpatient nephrology clinic, where moderate protein restriction (0.6⁻0.8 g/Kg/day) is routinely recommended to patients in CKD stage 3b-5 not on dialysis. METHODS: This observational study included 80 clinically-stable male out-patients aged >60, affected by stage 3b-4 CKD. Forty patients aged ≥75 (older seniors) were compared to the other forty patients aged 60⁻74 (younger seniors). All patients underwent a comprehensive nutritional and functional assessment. RESULTS: Older seniors showed lower serum albumin, hand-grip strength, body mass index (BMI), skeletal muscle mass, and resting energy expenditure. Protein intake was significantly lower in older seniors whereas energy intake was similar. Average daily physical activity was lower in the older seniors than in the younger ones. Sarcopenia was more prevalent in older than in younger seniors. Among older seniors, sarcopenic and non-sarcopenic ones differed in age and performance on the Six-Minute Walk test, whereas the estimated glomerular filtration rate (eGFR), biochemistry, dietary protein, and energy intakes were similar. CONCLUSIONS: Older senior CKD male patients have lower muscle mass, muscle strength, and physical capacity and activity levels, with a higher prevalence of sarcopenia than younger patients. This occurs at the same residual renal function and metabolic profile and protein intake. Energy intake was at the target in both subgroups. In this CKD cohort, sarcopenia was associated with age and physical capacity, but not with eGFR or dietary intakes.