High salt intake is associated with renal involvement in Japanese patients with type 2 diabetes mellitus

Dietitian-supported dietary intervention leads to favorable dietary changes in patients with type 2 diabetes: A randomized controlled trial

AIMS/INTRODUCTION

It remains to be fully elucidated whether nutrition education by dietitians can lead to specific positive changes in the food choices of patients with diabetes.

MATERIALS AND METHODS

A total of 96 patients with type 2 diabetes and diabetic kidney disease were randomly assigned to the intensive intervention group that received nutritional education at every outpatient visit and the control group that received nutritional education once a year. The total energy intake, energy-providing nutrients and 18 food groups were analyzed at baseline, and 1 and 2 years after the intervention in 87 patients. Furthermore, the relationship between the changes in hemoglobin A1c, body composition and changes in the total energy or energy-producing nutrient intake was analyzed in 48 patients who did not use or change hypoglycemic agents during the study period.

RESULTS

The total energy intake, carbohydrates, cereals, confections, nuts and seeds, and seasonings significantly decreased, and fish and shellfish intake significantly increased during the study period in the intensive intervention group, whereas these changes were not observed in the control group. The decrease in the total energy intake and carbohydrates after 2 years was significantly greater in the intensive intervention group than in the control group. The change in the total energy and carbohydrate intake showed a significant positive correlation with that in muscle mass. The multivariate analysis showed that the decrease in total energy intake was independently associated with that in muscle mass.

CONCLUSION

Dietitian-supported intensive dietary intervention helps improve the diet of patients with type 2 diabetes.

Comparison of the effects of frequent versus conventional nutritional interventions in patients with type 2 diabetes mellitus: A randomized, controlled trial

AIMS/INTRODUCTION

This randomized controlled trial aimed to determine whether frequent nutritional education improves the clinical parameters associated with the onset and progression of diabetic kidney disease in type 2 diabetes mellitus patients.

MATERIALS AND METHODS

A total of 96 patients with type 2 diabetes and diabetic kidney disease were randomly assigned to the intensive intervention group that received nutritional education at every outpatient visit, and the usual intervention group that received nutritional education once a year. The anthropometric parameters, blood pressure, blood chemistry, albuminuria, protein and salt intake, and prescribed medications of 87 patients who completed the 2-year follow up were analyzed.

RESULTS

In the intensive intervention group, body mass index and salt intake significantly decreased over the study period. Hemoglobin A1c levels and body fat percentage were significantly lower in the intensive intervention group than in the usual intervention group. At the end of the 2-year intervention period, the intensive intervention group had significantly lower salt intake (8.1 vs 9.4 g/day) than the usual intervention group. A significant positive correlation was found between salt intake and albuminuria in the overall group and intensive intervention group (r = 0.26, P = 0.02, and r = 0.36, P = 0.02, respectively). The intensive intervention group had a significantly lower insulin use rate than the usual intervention group after the 2-year intervention period (18% vs 42%). No differences were found in estimated glomerular filtration rate and albuminuria.

CONCLUSION

Intensive nutritional education is useful for alleviating the risk factors associated with the onset and progression of diabetic kidney disease.

Influence of Dietary Salt Intake on T2D Treatment

BACKGROUNDS

To what extent patients undergoing long-term T2D treatment are affected by dietary salt intake has not been completely investigated.

OBJECTIVES

We aimed to investigate the influence of dietary salt intakes on T2D treatment, including glucose-lowering effect and indices related to T2D progression.

METHODS

The study recruited 1090 patients with T2D at Ningbo City First Hospital from January 1, 2018, to December 30, 2021. We compared their one-year follow-up outcomes in terms of fasting blood glucose (FBG), glycated hemoglobin (HbA1c), blood pressure, obesity, and prevalence of retinopathy and neuropathy among groups with different dietary salt intakes.

RESULTS

The 1090 patients consisted of 287(26.3%) decreasing-, 190(17.4%) increasing-, 175(16.0%) steadily low-, 243(22.3%) steadily medium-, and 195(17.9%) steadily high-dietary salt intake patients. Compared to increasing-, steadily medium-, and steadily high-dietary salt intake patients, decreasing and steadily low salt intake led to lower baseline FBG, HbA1c, systolic blood pressure (SBP), BMI, and visceral fat area (VFA) (all p<0.05), to a larger decrease in FBG, HbA1c, SBP, BMI, and VFA after one-year treatment (all p<0.05), as well as to a slightly lower prevalence of retinopathy and a significantly lower prevalence of neuropathy. The steadily low salt patients had lower urine albumin/creatinine ratio (UAR) both at baseline and after treatment. Notably, the fasting insulin in the steadily low salt group was higher than the remaining groups after treatment (p<0.01).

CONCLUSIONS

The present study concludes that lowered dietary salt intake benefits T2D treatment in multiple aspects, including main treatment targets such as FBG and HbA1c, and indices reflecting potential complications of T2D, including BMI, VFA, SBP, UAR, retinopathy, and neuropathy.

CLINICAL TRIAL REGISTRATION

www.ClinicalTrials.gov, identifier: NCT03811470.

Association of Urinary Sodium Excretion and Diabetic Kidney Disease in Patients With Type 2 Diabetes Mellitus: A Cross-Sectional Study

BACKGROUND

Diabetic kidney disease (DKD) is the leading cause of end-stage kidney disease worldwide. Epidemiological evidence of the association between urinary sodium excretion and the presence of DKD in patients with type 2 diabetes mellitus (T2DM) has not yet been well established.

METHODS

We performed a cross-sectional study of 1545 patients with T2DM over aged 20 years old from January 2018 to December 2020. Urinary sodium excretion was measured by 24-hour urine samples in inpatients and morning fasting urine samples in outpatients. The associations between urinary sodium excretion and the risks of DKD were examined using stepwise regression analysis, logistic regression analysis and multivariable-adjusted restricted cubic splines (RCS).

RESULTS

Regression analysis showed that urinary sodium was independently associated with urinary albumin to creatinine ratio (UACR) level (P = 0.006) and the risks of DKD (P = 0.042). In multivariable-adjusted RCS analysis, urinary sodium excretion was significantly associated with UACR in all patients (P = 0.008), and exhibited a J-shaped relationship. Logistic regression analysis showed that increased urinary sodium excretion was significantly associated with increased risks of DKD [OR (95% CI); 1.56 (1.07-2.27); P = 0.020]. However, the relationships between urinary sodium excretion and the risks of DKD and albuminuria showed no significance, after further adjustment for HOMA-IR and ba-PWV (brachial-ankle pulse wave velocity) (Both P > 0.05).

CONCLUSIONS

Higher urinary sodium excretion level was associated with increased risks of DKD among patients with T2DM, dependent of vascular sclerosis and insulin resistance.

Association between 24-h urine sodium and proteinuria among hospitalized patients with type 2 diabetes

AIMS

This study used estimated sodium intake from 24-h urine sodium (24hU_Na) to explore the relationship of sodium intake with proteinuria among hospitalized patients with type 2 diabetes and with renal tubular injury markers [retinol-binding protein (RBP), beta 2-microglobulin (β₂-MG), N-acetyl-beta-D-glucosaminidase (NAG)].

METHODS

Hospitalized patients with type 2 diabetes (N = 269) were divided into two groups according to the median (0.08 g/day) 24-h urinary protein (24hU_pro) level. Logistic regression was used to analyze the association between 24hU_Na and 24hU_pro ≥ 0.08 g/L; scatter plots were used to analyze the association of RBP, β₂-MG, and NAG with 24hU_Na.

RESULTS

Overall, 269 patients with type 2 diabetes mellitus were enrolled (average age, 56 ± 12 years; men, 61.3%). Multivariate logistic regression analysis revealed a positive correlation between 24hU_Na and 24hU_pro ≥ 0.08 g/L; every 10 mmol of 24hU_Na had an increased risk of 24hU_pro elevation [odds ratio (OR) (95% confidence interval [CI]: 1.06 (1.01-1.11)]. Compared with the lowest quartile of 24hU_Na, the highest quartile had an increased risk of 24hU_pro elevation [OR (95% CI): 2.76 (1.25-6.05)]; 24hU_Na did not correlate with RBP, β₂-MG, or NAG.

CONCLUSIONS

In hospitalized patients with type 2 diabetes, 24hU_Na was independently related to 24hU_pro ≥ 0.08 g/day_. However, no correlation of 24hU_Na with RBP, β₂-MG, or NAG was found.

Targeting Inflammation in Diabetic Kidney Disease: Is There a Role for Pentoxifylline?

Diabetic kidney disease (DKD) is the most common cause of ESKD in the United States and worldwide. Current treatment for DKD includes strict glycemic control and normalization of BP with renin-angiotensin-aldosterone system (RAAS) blockade. Although RAAS blockers slow progression of disease, they do not generally prevent ESKD and none of the studies with these agents in DKD included patients who were nonproteinuric, which make up an increasingly large percentage of patients with diabetes now seen in clinical practice. Recent studies with glucagon-like peptide-1 receptor agonists and sodium-glucose cotransporter-2 (SGLT2) inhibitors have shown beneficial renal effects, and the benefits of SGLT2 inhibitors likely extend to patients who are nonproteinuric. However, there remains a need to develop new therapies for DKD, particularly in those patients with advanced disease. A role of chronic low-grade inflammation in microvascular complications in patients with diabetes has now been widely accepted. Large clinical trials are being carried out with experimental agents such as bardoxolone and selonsertib that target inflammation and oxidative stress. The Food and Drug Administration–approved, nonspecific phosphodiesterase inhibitor pentoxifylline (PTX) has been shown to have anti-inflammatory effects in both animal and human studies by inhibiting the production of proinflammatory cytokines. Small randomized clinical trials and meta-analyses indicate that PTX may have therapeutic benefits in DKD, raising the possibility that a clinically available drug may be able to be repurposed to treat this disease. A large, multicenter, randomized clinical trial to determine whether this agent can decrease time to ESKD or death is currently being conducted, but results will not be available for several years. At this time, the combination of RAAS blockade plus SGLT2 inhibition is considered standard of care for DKD, but it may be reasonable for clinicians to consider addition of PTX in patients whose disease continues to progress despite optimization of current standard-of-care therapies.

The Twin White Herrings: Salt and Sugar

India has the dubious distinction of being a hotspot for both diabetes and hypertension. Increased salt and sugar consumption is believed to fuel these two epidemics. This review is an in-depth analysis of current medical literature on salt and sugar being the two white troublemakers of modern society. The PubMed, Medline, and Embase search for articles published in January 2018, using the terms "salt" [MeSH Terms] OR "sodium chloride" [All Fields] OR "sugar" [All Fields]. India is world's highest consumer of sugar with one of the highest salt consumption per day. Increased salt intake is associated with increased risk of hypertension, left ventricular hypertrophy and fibrosis, cardiovascular events, renal stones, proteinuria, and renal failure. Increased sugar intake is directly linked to increased risk of obesity, fatty liver disease, and metabolic syndrome. Also, increased sugar intake may be indirectly related to the increased risk of type 2 diabetes. Both salt and sugar intake is directly linked to increased systemic and hypothalamic inflammation, endothelial dysfunction, microangiopathy, cardiovascular remodelling, cancers, and death. High fructose corn is especially damaging. There is no safe limit of sugar consumption, as the human body can produce its own glucose. Being nature's gift to mankind, there is no harm in moderate consumption of salt and sugar, however, modest reduction in the consumption of both can substantially reduce the burden of non-communicable diseases. Public health interventions to facilitate this behavioural change must be instituted and encouraged.

The relationship between diabetic risk factors, diabetic complications and salt intake

The relationship between salt and hypertension is the focus of a large amount of research, there are few reviews of the relationship between salt and diabetes, despite the increasing incidence of diabetes. By searching PubMed and the Cochrane Library, we summarized the relationships between diabetic risk factors, diabetic complications and salt intake. The pathophysiological mechanisms underlying the effects of salt on diabetes risk factors and diabetic complications are also discussed. Our findings should assist experts and scholars to understand the current research of salt intake and to pay more attention to the prevention and treatment of related diseases caused by excessive salt intake; guide treatment for patients with diabetes mellitus; and provide a reference for government departments to formulate a reasonable salt restriction policy. We also recommend future research directions.

High-Salt Enhances the Inflammatory Response by Retina Pigment Epithelium Cells following Lipopolysaccharide Stimulation

High-salt has been shown to play a role in the pathogenesis of autoimmune disease. In this study, we investigated the effect of high-salt on the production of inflammatory mediators by ARPE-19 cells and the possible mechanisms involved. ARPE-19 cells were cultured with LPS in DMEM to which extra NaCl had been added (20 mM and 40 mM). NaCl had no influence on the apoptosis and proliferation of ARPE-19. Addition of 40 mM NaCl significantly induced IL-6 and MCP-1 production but had no effect on IL-8 secretion. High mannitol, as an osmotic stress control, did not affect the secretion of inflammatory mediators by ARPE-19 cells indicating that the effect was not mediated by osmolarity. Coculture of ARPE-19 cells with NaCl resulted in significant increases in the phosphorylation of p38 MAPK, Akt, and NF-κB and an upregulation of the transcription factors NFAT5 and SGK1. High-salt significantly promotes IL-6 and MCP-1 production by ARPE-19 cells and is associated with activation of the p38 MAPK, Akt, and NF-κB pathway and NFAT-SGK1 pathways.