Effects of low-dose niacin on dyslipidemia and serum phosphorus in patients with chronic kidney disease

Association of dietary niacin intake with all-cause mortality in chronic kidney disease: A retrospective cohort study of NHANES

BACKGROUND

Dietary niacin intake has a positive influence on several chronic diseases, while the impact of dietary niacin intake on prognosis in chronic kidney disease (CKD) remains unknown. The study would explore the association between dietary niacin intake and all-cause mortality in CKD patients.

METHODS

Data about 4,659 CKD patients in this retrospective cohort study were obtained from the National Health and Nutrition Examinations Survey (NHANES). Dietary niacin intake data were acquired based on the 24-hour dietary recall interviews. Weighted univariate Cox regression models were utilized to select potential covariates. The association of dietary niacin intake with all-cause mortality was explored using weighted univariate and multivariate Cox regression models. The results were presented as hazard ratios (HRs) with 95% confidence intervals (CIs).

RESULTS

In total, 4,659 CKD patients were included in the study. The mean age of patients was 58.03 (0.42) years old, and 2,502 (58.45%) were female. During a mean follow-up of 73.92 (1.14) months, 1,325 (28.44%) CKD patients died. Compared to CKD patients with lower niacin intake ≤19mg, those with niacin intake >33 mg were associated with lower all-cause mortality risk (HR = 0.79, 95%CI: 0.64-0.98). The association also found in subgroups of age ≥65 years old (HR = 0.68, 95%CI: 0.53-0.88), males (HR = 0.68, 95%CI: 0.51-0.92), BMI <25 kg/m2 (HR = 0.63, 95%CI: 0.39-0.99), smoking (HR = 0.68, 95%CI: 0.49-0.94), dyslipidemia (HR = 0.71, 95%CI: 0.56-0.91), and non-hyperphosphatemia (HR = 0.73, 95%CI: 0.58-0.91).

CONCLUSION

Adequate dietary niacin intake was related to lower odds of all-cause mortality in CKD patients. Niacin supplements may have potential benefits for prognosis in CKD patients.

Identification of serum biomarkers for chronic kidney disease using serum metabolomics

This study aimed to identify biomarkers for chronic kidney disease (CKD) by studying serum metabolomics. Serum samples were collected from 194 non-dialysis CKD patients and 317 healthy controls (HC). Using ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS), untargeted metabolomics analysis was conducted. A random forest model was developed and validated in separate sets of HC and CKD patients. The serum metabolomic profiles of patients with chronic kidney disease (CKD) exhibited significant differences compared to healthy controls (HC). A total of 314 metabolites were identified as significantly different, with 179 being upregulated and 135 being downregulated in CKD patients. KEGG enrichment analysis revealed several key pathways, including arginine biosynthesis, phenylalanine metabolism, linoleic acid metabolism, and purine metabolism. The diagnostic efficacy of the classifier was high, with an area under the curve of 1 in the training and validation sets and 0.9435 in the cross-validation set. This study provides comprehensive insights into serum metabolism in non-dialysis CKD patients, highlighting the potential involvement of abnormal biological metabolism in CKD pathogenesis. Exploring metabolites may offer new possibilities for the management of CKD.

NAD+ enhancers as therapeutic agents in the cardiorenal axis

Cardiorenal diseases represent a complex interplay between heart failure and renal dysfunction, being clinically classified as cardiorenal syndromes (CRS). Recently, the contributions of altered nicotinamide adenine dinucleotide (NAD+) metabolism, through deficient NAD+ synthesis and/or elevated consumption, have proved to be decisive in the onset and progress of cardiorenal disease. NAD+ is a pivotal coenzyme in cellular metabolism, being significant in various signaling pathways, such as energy metabolism, DNA damage repair, gene expression, and stress response. Convincing evidence suggests that strategies designed to boost cellular NAD+ levels are a promising therapeutic option to address cardiovascular and renal disorders. Here, we review and discuss the implications of NAD+ metabolism in cardiorenal diseases, focusing on the propitious NAD+ boosting therapeutic strategies, based on the use of NAD+ precursors, poly(ADP-ribose) polymerase inhibitors, sirtuin activators, and other alternative approaches, such as CD38 blockade, nicotinamide phosphoribosyltransferase activation and combined interventions.

U-shaped association between dietary niacin intake and chronic kidney disease among US elderly: a nationwide cross-sectional study

Background

In addition to hypertension or diabetes, elderly people are also considered one of the high-risk groups for chronic kidney disease (CKD). Although niacin is recognized for its renal protective properties, the link between dietary niacin intake and CKD remains uncertain. This study investigated this relationship in the elderly.

Methods

We included participants aged 60 and older from the National Health and Nutrition Examination Survey (NHANES) for the years 2003-2018. Dietary niacin intake was assessed through two non-consecutive 24-hour dietary recalls. CKD was diagnosed in individuals with a urine albumin-to-creatinine ratio exceeding 30 mg/g or an estimated glomerular filtration rate below 60 mL/min per 1.73 m^2. The study cohort comprised 4,649 participants, 1,632 of whom had CKD. Propensity score matching (PSM) was utilized to adjust for baseline differences between the groups.

Results

Our analysis, using smooth curve fitting and generalized additive models both before and after PSM, found a U-shaped curve depicting the relationship between dietary niacin intake and CKD risk, confirmed by a log-likelihood ratio test (P < 0.05). Threshold effect analysis (after PSM) indicated a reduced risk of CKD in older adults with a niacin intake below 38.83 mg per day [odds ratio (OR) = 0.99, 95% confidence interval (CI) 0.97-1.00]. In contrast, higher intake levels significantly increased the risk (OR = 1.03, 95% CI 1.00-1.06). Subgroup analysis indicated that these associations were consistent across different stratification variables (P for interaction > 0.05).

Conclusion

Our findings suggested a U-shaped association between dietary niacin intake and CKD risk among older Americans. However, further prospective cohort studies are needed to confirm this finding.

Oxidative balance score and associations with dyslipidemia and mortality among US adults: A mortality follow-up study of a cross-sectional cohort

BACKGROUND

Oxidative stress has been implicated in the pathogenesis and progression of dyslipidemia. We aimed to investigate the association between the oxidative balance score, and dyslipidemia, as well as to assess the mortality risk associated with oxidative balance score in patients with dyslipidemia.

METHODS

We performed a mortality follow-up study of a cross-sectional cohort of 26,118 adults from the National Health and Nutrition Examination Survey 1999-2018. The total oxidative balance score was calculated by 16 dietary nutrients (dietary oxidative balance score) and four lifestyle factors (lifestyle oxidative balance score). Weighted Cox proportional hazard model was applied to determine the relationship between oxidative balance score and all-cause or cardiovascular disease (CVD) mortality within the dyslipidemia group.

RESULTS

During a median follow-up of 118 months, 2448 all-cause deaths (766 CVD-related) occurred. A significant negative correlation was observed between total oxidative balance score, dietary oxidative balance score, lifestyle oxidative balance score, and dyslipidemia. The multivariable-adjusted odds ratios and 95% CIs for dyslipidemia were 0.86 (0.77-0.97), 0.80 (0.72-0.91), and 0.63 (0.56-0.70), respectively, when comparing the second, third, and fourth quartiles of total oxidative balance score to the reference lowest quartile (P for trend <0.0001). Increasing total oxidative balance score was inversely associated with all-cause (hazard ratio [HR] = 0.98, 95% CI 0.98-0.99) and CVD-specific mortality (HR = 0.98, 95% CI 0.97-0.99) in participants with dyslipidemia.

CONCLUSIONS

Oxidative balance score is inversely associated with dyslipidemia and linked to all-cause and CVD-related mortality, highlighting the potentially protective role of an antioxidant-rich diet against dyslipidemia.

Changes in glucose metabolism, C-reactive protein, and liver enzymes following intake of NAD + precursor supplementation: a systematic review and meta-regression analysis

BACKGROUND

There are contradictory effects regarding the effect of NAD + precursor on glucose metabolism and liver enzymes. In order to obtain a better viewpoint from them, this study aimed to comprehensively investigate the effects of NAD + precursor supplementation on glucose metabolism, C-reactive protein (CRP), and liver enzymes.

METHODS

PubMed/MEDLINE, Web of Science, SCOPUS, and Embase databases were searched using standard keywords to identify all controlled trials investigating the glucose metabolism, CRP, and liver enzymes effects of NAD + precursor. Pooled weighted mean difference (WMD) and 95% confidence intervals (95% CI) were achieved by random-effects model analysis for the best estimation of outcomes.

RESULTS

Forty-five articles with 9256 participants' were included in this article. The pooled findings showed that NAD + precursor supplementation had a significant increase in glucose (WMD: 2.17 mg/dL, 95% CI: 0.68, 3.66, P = 0.004) and HbA1c (WMD: 0.11, 95% CI: 0.06, 0.16, P < 0.001) as well as a significant decrease in CRP (WMD: -0.93 mg/l, 95% CI -1.47 to -0.40, P < 0.001) compared with control group, and was not statistically significant with respect to insulin and homeostasis model assessment of insulin resistance (HOMA-IR). However, we found no systemic changes in aspartate transaminase (AST), alanine transaminase (ALT), or alkaline phosphatase (ALP) levels after NAD + precursor supplementation. The results of the subgroup analysis showed that the intake of NAD + precursor during the intervention of more than 12 weeks caused a greater increase in the glucose level. Furthermore, Nicotinic acid supplementation (NA) causes a greater increase in glucose and HbA1c levels than nicotinamide (NE) supplementation.

CONCLUSIONS

Overall, these findings suggest that NAD + precursor supplementation might have an increase effect on glucose metabolism as well as a decrease in CRP.

Vitamin Supplement Use in Patients With CKD: Worth the Pill Burden?

All vitamins play essential roles in various aspects of body function and systems. Patients with chronic kidney disease (CKD), including those receiving dialysis, may be at increased risk of developing vitamin deficiencies due to anorexia, poor dietary intake, protein energy wasting, restricted diet, dialysis loss, or inadequate sun exposure for vitamin D. However, clinical manifestations of most vitamin deficiencies are usually subtle or undetected in this population. Testing for circulating levels is not undertaken for most vitamins except folate, B12, and 25-hydroxyvitamin D because assays may not be available or may be costly to perform and do not always correlate with body stores. The last systematic review through 2016 was performed for the Kidney Disease Outcome Quality Initiative (KDOQI) 2020 Nutrition Guideline update, so this article summarizes the more recent evidence. We review the use of vitamins supplementation in the CKD population. To date there have been no randomized trials to support the benefits of any vitamin supplementation for kidney, cardiovascular, or patient-centered outcomes. The decision to supplement water-soluble vitamins should be individualized, taking account the patient's dietary intake, nutritional status, risk of vitamins deficiency/insufficiency, CKD stage, comorbid status, and dialysis loss. Nutritional vitamin D deficiency should be corrected, but the supplementation dose and formulation need to be personalized, taking into consideration the degree of 25-hydroxyvitamin D deficiency, parathyroid hormone levels, CKD stage, and local formulation. Routine supplementation of vitamins A and E is not supported due to potential toxicity. Although more trial data are required to elucidate the roles of vitamin supplementation, all patients with CKD should undergo periodic assessment of dietary intake and aim to receive various vitamins through natural food sources and a healthy eating pattern that includes vitamin-dense foods.

Kidney lipid dysmetabolism and lipid droplet accumulation in chronic kidney disease

Chronic kidney disease (CKD) is a global health problem with rising incidence and prevalence. Among several pathogenetic mechanisms responsible for disease progression, lipid accumulation in the kidney parenchyma might drive inflammation and fibrosis, as has been described in fatty liver diseases. Lipids and their metabolites have several important structural and functional roles, as they are constituents of cell and organelle membranes, serve as signalling molecules and are used for energy production. However, although lipids can be stored in lipid droplets to maintain lipid homeostasis, lipid accumulation can become pathogenic. Understanding the mechanisms linking kidney parenchymal lipid accumulation to CKD of metabolic or non-metabolic origin is challenging, owing to the tremendous variety of lipid species and their functional diversity across different parenchymal cells. Nonetheless, multiple research reports have begun to emphasize the effect of dysregulated kidney lipid metabolism in CKD progression. For example, altered cholesterol and fatty acid metabolism contribute to glomerular and tubular cell injury. Newly developed lipid-targeting agents are being tested in clinical trials in CKD, raising expectations for further therapeutic development in this field.

Does Vitamin Supplementation Play a Role in Chronic Kidney Disease?

Although the role of vitamins in the human body is proven, guidelines for patients with chronic kidney disease (CKD) remain unclear. This narrative review summarizes the findings of 98 studies of CKD and the effects of vitamin D, B, C, A, E, and K supplementation on patients on dialysis for CKD, with the aim of summarizing the existing guidelines. The findings are promising, showing the potential effectiveness of vitamin supplementation with, for example, vitamins B, D, or C. However, recommendations are still ambiguous, especially in the case of vitamins A and K, due to the potential toxicity associated with higher doses for patients. Continued research is needed to rigorously evaluate the effectiveness and carefully consider the potential risks of some vitamin supplementation for patients with CKD.

Roles of NAD+ in Acute and Chronic Kidney Diseases

Nicotinamide adenine dinucleotide (oxidized form, NAD⁺) is a critical coenzyme, with functions ranging from redox reactions and energy metabolism in mitochondrial respiration and oxidative phosphorylation to being a central player in multiple cellular signaling pathways, organ resilience, health, and longevity. Many of its cellular functions are executed via serving as a co-substrate for sirtuins (SIRTs), poly (ADP-ribose) polymerases (PARPs), and CD38. Kidney damage and diseases are common in the general population, especially in elderly persons and diabetic patients. While NAD⁺ is reduced in acute kidney injury (AKI) and chronic kidney disease (CKD), mounting evidence indicates that NAD⁺ augmentation is beneficial to AKI, although conflicting results exist for cases of CKD. Here, we review recent progress in the field of NAD⁺, mainly focusing on compromised NAD⁺ levels in AKI and its effect on essential cellular pathways, such as mitochondrial dysfunction, compromised autophagy, and low expression of the aging biomarker αKlotho (Klotho) in the kidney. We also review the compromised NAD⁺ levels in renal fibrosis and senescence cells in the case of CKD. As there is an urgent need for more effective treatments for patients with injured kidneys, further studies on NAD⁺ in relation to AKI/CKD may shed light on novel therapeutics.

NAD+ Metabolism and Interventions in Premature Renal Aging and Chronic Kidney Disease

Premature aging causes morphological and functional changes in the kidney, leading to chronic kidney disease (CKD). CKD is a global public health issue with far-reaching consequences, including cardio-vascular complications, increased frailty, shortened lifespan and a heightened risk of kidney failure. Dialysis or transplantation are lifesaving therapies, but they can also be debilitating. Currently, no cure is available for CKD, despite ongoing efforts to identify clinical biomarkers of premature renal aging and molecular pathways of disease progression. Kidney proximal tubular epithelial cells (PTECs) have high energy demand, and disruption of their energy homeostasis has been linked to the progression of kidney disease. Consequently, metabolic reprogramming of PTECs is gaining interest as a therapeutic tool. Preclinical and clinical evidence is emerging that NAD⁺ homeostasis, crucial for PTECs' oxidative metabolism, is impaired in CKD, and administration of dietary NAD⁺ precursors could have a prophylactic role against age-related kidney disease. This review describes the biology of NAD⁺ in the kidney, including its precursors and cellular roles, and discusses the importance of NAD⁺ homeostasis for renal health. Furthermore, we provide a comprehensive summary of preclinical and clinical studies aimed at increasing NAD⁺ levels in premature renal aging and CKD.

Is Niacine a Potential Agent to Decrease Dyslipidemia Risk?

Cardiovascular diseases are the most common non-communicable diseases with the highest prevalence and mortality rate in the all around the world. There are some risk factors -such as modifiable and non-modifiable- which are effective on the development of these diseases. Modifiable risk factors are closely related to dyslipidemia, which forms the basis of cardiovascular diseases. Dyslipidemia is characterized by high triacylglycerol (TAG) and free fatty acids, decreased high density lipoprotein (HDL) level and function, increased low density lipoprotein (LDL) level and apolipoprotein B (Apo B) production. There is a relation between dyslipidemia with nutritional and physical activity behaviors. In particular, adherence to the Mediterranean diet and lifestyle behaviors instead of the Western diet can potentially decrease dyslipidemia risk. On the other hand, some of micronutrients such as niacin can potentially decrease dyslipidemia risk as a nutritional supplement. Niacin -which is a water-soluble, B group vitamin- can potentially decrease TAG, free fatty acids, Apo B, very low density lipoprotein (VLDL) and LDL levels and increase HDL and apolipoprotein A (Apo A) levels in plasma. Due to these potential beneficial effects, niacin acts a pharmacological agent to decrease both of dyslipidemia risk and symptoms. However, niacin is used more than tolerable upper intake level (35 mg/day) to show these potential effects (1-3 g). This situation may cause to ‘niacin flush’ symptom. In addition, there is a need for the studies which aim to determine the negative effects of high dose niacin intake on human’s health in long-term. In this review article, potential effects of the niacin on dyslipidemia are examined within the current literature.

NAD+ homeostasis in human health and disease

Depletion of nicotinamide adenine dinucleotide (NAD+ ), a central redox cofactor and the substrate of key metabolic enzymes, is the causative factor of a number of inherited and acquired diseases in humans. Primary deficiencies of NAD+ homeostasis are the result of impaired biosynthesis, while secondary deficiencies can arise due to other factors affecting NAD+ homeostasis, such as increased NAD+ consumption or dietary deficiency of its vitamin B3 precursors. NAD+ depletion can manifest in a wide variety of pathological phenotypes, ranging from rare inherited defects, characterized by congenital malformations, retinal degeneration, and/or encephalopathy, to more common multifactorial, often age-related, diseases. Here, we discuss NAD+ biochemistry and metabolism and provide an overview of the etiology and pathological consequences of alterations of the NAD+ metabolism in humans. Finally, we discuss the state of the art of the potential therapeutic implications of NAD+ repletion for boosting health as well as treating rare and common diseases, and the possibilities to achieve this by means of the different NAD+ -enhancing agents.

NAD+ homeostasis in health and disease

The conceptual evolution of nicotinamide adenine dinucleotide (NAD⁺) from being seen as a simple metabolic cofactor to a pivotal cosubstrate for proteins regulating metabolism and longevity, including the sirtuin family of protein deacylases, has led to a new wave of scientific interest in NAD⁺. NAD⁺ levels decline during ageing, and alterations in NAD⁺ homeostasis can be found in virtually all age-related diseases, including neurodegeneration, diabetes and cancer. In preclinical settings, various strategies to increase NAD⁺ levels have shown beneficial effects, thus starting a competitive race to discover marketable NAD⁺ boosters to improve healthspan and lifespan. Here, we review the basics of NAD⁺ biochemistry and metabolism, and its roles in health and disease, and we discuss current challenges and the future translational potential of NAD⁺ research.

Pleiotropic effects of niacin: Current possibilities for its clinical use

Niacin was the first hypolipidemic drug to significantly reduce both major cardiovascular events and mortality in patients with cardiovascular disease. Niacin favorably influences all lipoprotein classes, including lipoprotein[a],and belongs to the most potent hypolipidemic drugs for increasing HDL-C. Moreover, niacin causes favorable changes to the qualitative composition of lipoprotein HDL. In addition to its pronounced hypolipidemic action, niacin exerts many other, non-hypolipidemic effects (e.g., antioxidative, anti-inflammatory, antithrombotic), which favorably influence the development and progression of atherosclerosis. These effects are dependent on activation of the specific receptor HCA2. Recent results published by the two large clinical studies, AIM-HIGH and HPS2-THRIVE, have led to the impugnation of niacin's role in future clinical practice. However, due to several methodological flaws in the AIM-HIGH and HPS2-THRIVE studies, the pleiotropic effects of niacin now deserve thorough evaluation. This review summarizes the present and possible future use of niacin in clinical practice in light of its newly recognized pleiotropic effects.

Effect of low dose nicotinic acid on hyperphosphatemia in patients with end stage renal disease

Hyperphosphatemia is a risk factor for ectopic calcification and coronary artery diseases in end stage renal diseases (ESRD). The aim of this study was to assess the effect of low-dose nicotinic acid on hyperphosphatemia in patients with ESRD. This randomized, double-blind clinical trial was done on 70 ESRD patients with serum phosphoure ≥5.5 mg/dl. Patients were randomly divided into two equal groups (n = 35) and the intervention group received niacin 25 mg/day as the initial dose. After 4 weeks, in patients who did not respond to treatment, niacin dose was increased up to 50 mg/dl. At the end of week 8, in case there was no treatment effect, the dose was raised to 100 mg/day. The appropriate response to treatment was defined as serum phosphorous level reductions <5.5 mg/dl. The age was 50.5 ± 14.3 years and duration of dialysis 5.1 ± 5.3 months. In the niacin group, mean phosphorus level decreased from 6.7 ± 0.84 mg/dl at the end of the 1(st) month to 5.8 ± 1.0 mg/dl at the end of the 2(nd) month and to 4.4 ± 1.4 mg/dl at the end of the 3(rd) month (P = 0.004). In the placebo group, mean phosphorus level increased from 6.5 ± 1.2 mg/dl to 7.2 ± 0.91 mg/dl at the end of the 3(rd) month (P = 0.006). In the niacin group, high density lipoprotein (HDL) increased significantly from 45.00 ± 14.9 to 47.2 ± 11.6 (P = 0.009). We conclude that niacin (100 mg/day) decreased phosphorus serum level and increased HDL serum level in patients on dialysis.

Hypophosphatemic effect of niacin extended release in ischemic kidney disease

Ischemic nephropathy is an emerging cause of end stage renal disease, associated with many co-morbidities especially cardiovascular disease risk and derangement in calcium-phosphorus homeostasis resulting in hyperphosphatemia, influencing bones, a characteristic of advancing chronic kidney disease. The management of elevated serum phosphorus has been a challenge in this patient population with compromised kidney performance, as available phosphorus lowering agents possess many undesirable hazardous secondary effects and/or are very expensive. While niacin in different formulation is known to not only correct dyslipidemia but also reduce phosphorus level, but its clinical use restricted owing to side effects. The objective of present study is to evaluate such effect of niacin extended release (NER) in ischemic nephropathy. The chronic kidney disease patients fulfilling the pre-defined criteria were randomly categorized into two groups of equal size (n=60) and prescribed either atorvastatin 20 mg/day or NER 500 mg/day with the same dose of statin for four months. A control of 50 healthy characters matched was also incorporated for local reference range. Baseline and follow up phosphorus concentration was measured and means were compared using t-test at SPSS version 17 with 0.05 chosen alpha. There was no difference in the baseline levels in both groups while significant (p<0.001) hyperphosphatemia was observed in both units as compared with healthy controls. The administration of atorvastatin alone for four weeks showed an insignificant decrease in phosphorus, whereas, NER significantly reduced phosphorus (p<0.001). The mean percent change from baseline to follow up further endorsed the finding as statin alone brought -13.8 % reduction in phosphorus and NER -47 % from baseline. NER, at its lowest prescribed dose once a day was well tolerated by most of the patients and demonstrated significant goal achievement of phosphorus reduction. It is concluded that NER even at low doses in renal compromised dyslipidemic patients may be a promising approach to prevent the harmful vascular, valvular effects caused by hyperphosphatemia in addition to its principal target of HDL-C elevation.