Multilayered Interplay Between Fructose and Salt in Development of Hypertension

Association between soft drinks intake and low glomerular filtration rate in Mexican adults: Results from RenMex

BACKGROUND & AIMS

To evaluate the association between soft drinks (SDs) consumption and estimated glomerular filtration rate (eGFR) in a Mexican adult population.

METHODS

We used data from the RenMex consortium (n = 2095) that included the Mexican Teachers Cohort Study (34-65 years), the Health Workers Cohort Study (18-90 years), and the Comitán Study (19-91 years). In this cross-sectional study, we assessed SDs consumption (cola and flavored soda) using a food frequency questionnaire (FFQ) and estimated eGFR using the CKD Epidemiology Collaboration equation. Quantile regression was used to assess the association between SDs consumption and eGFR with eGFR as a continuous variable. Multinomial logistic regression models were used for eGFR categories derived from quantile regression (mildly decreased eGFR, ≥72.9-87.9 mL/min/1.73 m2 and moderately decreased eGFR, <72.9 mL/min/1.73 m2).

RESULTS

Mean age of study participants was 47.2 years, 67.5% were women, and 12.2% had diabetes. eGFR was <60 mL/min/1.73 m2 in 3.7% of study participants. Mildly decreased eGFR was present in 14.8%, and moderately decreased eGFR was present in 10.1% of study participants. Quantile regression results showed that SDs consumption was associated with lower eGFR at the 10th, 25th, 50th and 75th percentile. Based on the final adjusted multinomial model, ≥7 servings/week was positively associated with moderately decreased eGFR relative to <1 serving/week (Relative Risk Ratio = 1.95; 95% CI: 1.07-3.57).

CONCLUSION

Our results suggest that higher SDs consumption is associated with lower eGFR. Encouraging healthy dietary choices should be part of the management and prevention of CKD.

Profiling Cell Heterogeneity and Fructose Transporter Expression in the Rat Nephron by Integrating Single-Cell and Microdissected Tubule Segment Transcriptomes

Single-cell RNA sequencing (scRNAseq) is a crucial tool in kidney research. These technologies cluster cells based on transcriptome similarity, irrespective of the anatomical location and order within the nephron. Thus, a transcriptome cluster may obscure the heterogeneity of the cell population within a nephron segment. Elevated dietary fructose leads to salt-sensitive hypertension, in part, through fructose reabsorption in the proximal tubule (PT). However, the organization of the four known fructose transporters in apical PTs (SGLT4, SGLT5, GLUT5, and NaGLT1) remains poorly understood. We hypothesized that cells within each subsegment of the proximal tubule exhibit complex, heterogeneous fructose transporter expression patterns. To test this hypothesis, we analyzed rat kidney transcriptomes and proteomes from publicly available scRNAseq and tubule microdissection databases. We found that microdissected PT-S1 segments consist of 81% ± 12% cells with scRNAseq-derived transcriptional characteristics of S1, whereas PT-S2 express a mixture of 18% ± 9% S1, 58% ± 8% S2, and 19% ± 5% S3 transcripts, and PT-S3 consists of 75% ± 9% S3 transcripts. The expression of all four fructose transporters was detectable in all three PT segments, but key fructose transporters SGLT5 and GLUT5 progressively increased from S1 to S3, and both were significantly upregulated in S3 vs. S1/S2 (Slc5a10: 1.9 log2FC, p < 1 × 10-299; Scl2a5: 1.4 log2FC, p < 4 × 10-105). A similar distribution was found in human kidneys. These data suggest that S3 is the primary site of fructose reabsorption in both humans and rats. Finally, because of the multiple scRNAseq transcriptional phenotypes found in each segment, our findings also imply that anatomical labels applied to scRNAseq clusters may be misleading.

A new immune disease: systemic hypertension

Systemic hypertension is the most common medical comorbidity affecting the adult population globally, with multiple associated outcomes including cerebrovascular diseases, cardiovascular diseases, vascular calcification, chronic kidney disease, metabolic syndrome and mortality. Despite advancements in the therapeutic field approximately one in every five adult patients with hypertension is classified as having treatment-resistant hypertension, indicating the need for studies to provide better understanding of the underlying pathophysiology and the need for more therapeutic targets. Recent pre-clinical studies have demonstrated the role of the innate and adaptive immune system including various cell types and cytokines in the pathophysiology of hypertension. Moreover, pre-clinical studies have indicated the potential beneficial effects of immunosuppressant medications in the control of hypertension. Nevertheless, it is unclear whether such pathophysiological mechanisms and therapeutic alternatives are applicable to human subjects, while this area of research is undoubtedly a rapidly growing field.

Modulation of the Gut Microbiota by Fufang-Zhenzhu-Tiaozhi Capsule Attenuates Hypertension Induced by a High-Fructose and High-Salt Diet

Hypertension is frequently comorbid with the disorders of glucose and lipid metabolism. The increased intakes of fructose and salt contribute to the development of hypertension and related metabolic disorders, which are closely associated with gut dysbiosis. Fufang-Zhenzhu-Tiaozhi capsule (FTZ), a traditional Chinese patent medicine commonly used in clinical practice, has recently emerged as a promising drug candidate for metabolic diseases. In this study, FTZ treatment is identified as attenuating blood pressure increase and improving the metabolism of lipid and uric acid in high-fructose and high-salt (HFS) diet-fed rats. FTZ also substantially alleviated renal fibrosis and the mRNA expression of inflammation cytokines, NADPH oxidases, and the renin–angiotensin system in the renal cortex. 16S rRNA sequencing of fecal samples revealed that FTZ restored HFS-induced gut dysbiosis, seen as increased intestinal microbial richness and diversity. Furthermore, fecal microbiota transplantation also achieved similar therapeutic effects and alterations in gut microbiota profile induced by FTZ. Taken together, this study highlights the efficacy of FTZ in attenuating HFS-induced hypertension and related metabolic disorders and renal injury. The antihypertensive effect is associated with the modulation of gut microbiota.

Impact of Dietary Fructose and High Salt Diet: Are Preclinical Studies Relevant to Asian Societies?

Fructose consumption, especially in food additives and sugar-sweetened beverages, has gained increasing attention due to its potential association with obesity and metabolic syndrome. The relationship between fructose and a high-salt diet, leading to hypertension and other deleterious cardiovascular parameters, has also become more evident, especially in preclinical studies. However, these studies have been modeled primarily on Western diets. The purpose of this review is to evaluate the dietary habits of individuals from China, Japan, and Korea, in light of the existing preclinical studies, to assess the potential relevance of existing data to East Asian societies. This review is not intended to be exhaustive, but rather to highlight the similarities and differences that should be considered in future preclinical, clinical, and epidemiologic studies regarding the impact of dietary fructose and salt on blood pressure and cardiovascular health worldwide.

Mechanism-based strategies to prevent salt sensitivity and salt-induced hypertension

High-salt diets are a major cause of hypertension and cardiovascular (CV) disease. Many governments are interested in using food salt reduction programs to reduce the risk for salt-induced increases in blood pressure and CV events. It is assumed that reducing the salt concentration of processed foods will substantially reduce mean salt intake in the general population. However, contrary to expectations, reducing the sodium density of nearly all foods consumed in England by 21% had little or no effect on salt intake in the general population. This may be due to the fact that in England, as in other countries including the U.S.A., mean salt intake is already close to the lower normal physiologic limit for mean salt intake of free-living populations. Thus, mechanism-based strategies for preventing salt-induced increases in blood pressure that do not solely depend on reducing salt intake merit attention. It is now recognized that the initiation of salt-induced increases in blood pressure often involves a combination of normal increases in sodium balance, blood volume and cardiac output together with abnormal vascular resistance responses to increased salt intake. Therefore, preventing either the normal increases in sodium balance and cardiac output, or the abnormal vascular resistance responses to salt, can prevent salt-induced increases in blood pressure. Suboptimal nutrient intake is a common cause of the hemodynamic disturbances mediating salt-induced hypertension. Accordingly, efforts to identify and correct the nutrient deficiencies that promote salt sensitivity hold promise for decreasing population risk of salt-induced hypertension without requiring reductions in salt intake.

Fructose plus High-Salt Diet in Early Life Results in Salt-Sensitive Cardiovascular Changes in Mature Male Sprague Dawley Rats

Fructose and salt intake remain high, particularly in adolescents and young adults. The present studies were designed to evaluate the impact of high fructose and/or salt during pre- and early adolescence on salt sensitivity, blood pressure, arterial compliance, and left ventricular (LV) function in maturity. Male 5-week-old Sprague Dawley rats were studied over three 3-week phases (Phases I, II, and III). Two reference groups received either 20% glucose + 0.4% NaCl (GCS-GCS) or 20% fructose + 4% NaCl (FHS-FHS) throughout this study. The two test groups ingested fructose + 0.4% NaCl (FCS) or FHS during Phase I, then GCS in Phase II, and were then challenged with 20% glucose + 4% NaCl (GHS) in Phase III: FCS-GHS and FHS-GHS, respectively. Compared with GCS-GCS, systolic and mean pressures were significantly higher at the end of Phase III in all groups fed fructose during Phase I. Aortic pulse wave velocity (PWV) was elevated at the end of Phase I in FHS-GHS and FHS-FHS (vs. GCS-GCS). At the end of Phase III, PWV and renal resistive index were higher in FHS-GHS and FHS-FHS vs. GCS-GCS. Diastolic, but not systolic, LV function was impaired in the FHS-GHS and FHS-FHS but not FCS-FHS rats. Consumption of 20% fructose by male rats during adolescence results in salt-sensitive hypertension in maturity. When ingested with a high-salt diet during this early plastic phase, dietary fructose also predisposes to vascular stiffening and LV diastolic dysfunction in later life.

Vitamin D3 potentiates the nephroprotective effects of vildagliptin-metformin combination in a rat model of metabolic syndrome

The current study was conducted to investigate the nephroprotective effects of vildagliptin-metformin combination in an experimental model of fructose/salt-induced metabolic syndrome (MetS). A major aim was to evaluate the potential capacity of vitamin D3 to potentiate the pleiotropic nephroprotective effects of vildagliptin-metformin combination. MetS was induced in adult male Wistar rats by adding fructose (10%) to everyday drinking water and salt (3%) to the diet for 6 weeks. Along with the same concentrations of fructose/salt feeding, MetS rats were then treated orally with either vildagliptin (10 mg/kg/day)-metformin (200 mg/kg/day) combination, vitamin D3 (10 μg/kg/day), or the triple therapy for a further 6 weeks. The incidence of MetS was confirmed 6 weeks after fructose/salt consumption, when the rats exhibited significant weight gain, dyslipidemia, hyperuricemia, insulin resistance, hyperinsulinemia, and impaired glucose tolerance. At the end of the 12-week experimental period, MetS rats displayed significantly deteriorated renal function, enhanced intrarenal oxidative stress and inflammation together with exaggerated renal histopathological damages and interstitial fibrosis. The study has corroborated antioxidant, anti-inflammatory, and antifibrotic effects of vildagliptin-metformin combination, vitamin D3, and the triple collaborative therapy, conferring renoprotection in the setting of MetS. Due attention has been paid to the crucial role of dipeptidyl peptidase-4 inhibition and sirtuin-1/5' adenosine monophosphate-activated protein kinase activation as novel therapeutic targets to optimize renoprotection. The apparent potentiating effect, evoked upon coadministration of vitamin D3 with vildagliptin-metformin combination, may provide a cornerstone for further clinical investigations.

Development of rat metabolic syndrome models: A review

Metabolic syndrome (MetS) has become a global problem. With the increasing prevalence of MetS worldwide, understanding its pathogenesis and treatment modalities are essential. Animal models should allow an appropriate representation of the clinical manifestations of human conditions. Rats are the most commonly used experimental animals for the study. The development of a proper MetS model using rats will contribute to the successful application of research findings to the clinical setting. Various intervention methods are used to induce MetS through diet induction with various compositions, chemicals, or a combination of both. This review will provide a comprehensive overview of several studies on the development of rat MetS models, along with the characteristics of the clinical manifestations resulting from each study.

Impact of Uric Acid on Hypertension Occurrence and Target Organ Damage: Insights From the STANISLAS Cohort With a 20-Year Follow-up

BACKGROUND

Recent studies have shown that hyperuricemia may be associated with incident hypertension (HTN). We examined whether serum uric acid (SUA) is a predictor of HTN and target organ damage (TOD) 20 years later in initially healthy middle-aged individuals.

METHODS

Participants from the Suivi Temporaire Annuel Non-Invasif de la Santé des Lorrains Assurés Sociaux (STANISLAS) a single-center familial longitudinal cohort study (961 initially healthy adults and 570 children) underwent clinical and laboratory measurements at baseline and after approximately 20 years. Blood pressure (BP: using ambulatory BP measurements), urine albumin-to-creatinine ratio, estimated glomerular filtration rate (eGFR), left ventricular hypertrophy (LVH), diastolic dysfunction, and carotid-femoral pulse wave velocity (PWV) were measured at the end of follow-up.

RESULTS

In the parent population, higher baseline or last SUA levels and higher change in SUA (ΔUA) were significantly associated with an increased risk of HTN development, even after adjusting for known HTN risk factors (all P < 0.01). Higher baseline SUA was marginally associated with an increased risk of having high carotid-femoral PWV (P = 0.05). The association of SUA with BP increase was body mass index dependent (the increase in BP being greater in leaner subjects; interactionp < 0.05), and the association of SUA with eGFR decline was age dependent (the decline in eGFR being greater in older subjects; interactionp < 0.05). There was no significant association between SUA and diastolic dysfunction or LVH. In the whole population (i.e. including children), a significant association between SUA at baseline and the risk of HTN and higher carotid-femoral PWV was also found (both P < 0.02).

CONCLUSIONS

Increased SUA is associated with the development of HTN and vascular/renal TOD in initially healthy midlife subjects.

Renoprotective effects of vitamin D3 supplementation in a rat model of metabolic syndrome

PURPOSE

The study aimed to investigate the potential nephroprotective effects of vitamin D3 in metabolic syndrome (MetS) and the molecular basis of the underlying mechanisms of its action.

METHODS

MetS was induced in adult male Wistar rat‏s by adding fructose (10%) to every day drinking water and salt (3%) to the diet. Six weeks after fructose/salt consumption, fasting serum lipid profile and uric acid levels were determined, an oral glucose tolerance test (OGTT) was performed and kidney function was checked. MetS rats were then treated orally with vitamin D3 (10 µg/kg/day) for 6 weeks. At the end of the study period (12 weeks), the OGTT test was reperformed, anthropometrical parameters were measured, urine, blood and tissue samples were collected and the animals were euthanised.

RESULTS

The incidence of MetS was confirmed 6 weeks after fructose/salt consumption, when the rats exhibited significant weight gain, dyslipidemia, hyperuricemia, insulin resistance, hyperinsulinemia and impaired glucose tolerance. After 12 weeks, MetS rats displayed markedly declined renal function alongside with extravagant renal histopathological damages and interstitial fibrosis. Furthermore, significantly enhanced renal oxidative stress and inflammation were manifested. Vitamin D3 supplementation in MetS rats significantly reversed all the above-mentioned deleterious effects.

CONCLUSION

The study has indeed provided mounting evidence of the promising therapeutic potential of vitamin D3 against development and progression of MetS-induced nephropathy. A new insight has been introduced into the crucial role of dipeptidyl peptidase-4 inhibition and sirtuin-1/5'adenosine monophosphate-activated protein kinase activation in the renoprotective effects of vitamin D3.

Vitamin D3 potentiates the renoprotective effects of vildagliptin in a rat model of fructose/salt-induced insulin resistance

Insulin resistance (IR) seemingly plays a role in chronic kidney disease (CKD). The present study has elucidated the crucial interplay of oxidative stress, inflammatory, apoptotic and profibrotic signaling pathways, linking IR to CKD. The study aimed at investigating the pleiotropic nephroprotective effects of either vildagliptin or vitamin D3 in a fructose/salt-induced IR rat model, highlighting the potential molecular mechanisms underlying their action. Another interesting target was to evaluate the potential capacity of vitamin D3 to potentiate the nephroprotective effects of vildagliptin. Indeed, a state of impaired fasting glucose, IR and compensatory hyperinsulinemia, constellating with significant weight gain, atherogenic dyslipidemia and hyperuricemia was established 6 weeks after fructose/salt consumption. IR rats were then treated orally with vildagliptin (10 mg/kg/day), vitamin D3 (10 µg/kg/day) or their combination for a further 6 weeks. By the end of the 12^th week, untreated IR rats displayed significantly declined renal function with parallel interwined renal oxidative stress, inflammatory, apoptotic and profibrotic changes, renal histopathological damages and markedly enhanced collagen fiber deposition. Vildagliptin and vitamin D3 reversed hyperuricemia and exerted a plethora of renal anti-oxidant, anti-inflammatory, anti-apoptotic and anti-fibrotic effects. Our study has introduced a new insight into the role of dipeptidyl peptidase-4 inhibition and silent information regulator 1/5'adenosine monophosphate-activated protein kinase activation in the nephroprotective effects of either agent, elucidating their possible crosstalk with renin angiotensin aldosterone system downregulation. Considering the superadditive renoprotective effects evoked by the combination, vitamin D3 is worth being further investigated as an additional therapeutic agent for preventing IR-induced nephropathy.

Österreichischer Blutdruckkonsens 2019

Erhöhter Blutdruck bleibt eine Hauptursache von kardiovaskulären Erkrankungen, Behinderung und frühzeitiger Sterblichkeit in Österreich, wobei die Raten an Diagnose, Behandlung und Kontrolle auch in rezenten Studien suboptimal sind. Das Management von Bluthochdruck ist eine häufige Herausforderung für Ärztinnen und Ärzte vieler Fachrichtungen. In einem Versuch, diagnostische und therapeutische Strategien zu standardisieren und letztendlich die Rate an gut kontrollierten Hypertoniker/innen zu erhöhen und dadurch kardiovaskuläre Erkrankungen zu verhindern, haben 13 österreichische medizinische Fachgesellschaften die vorhandene Evidenz zur Prävention, Diagnose, Abklärung, Therapie und Konsequenzen erhöhten Blutdrucks gesichtet. Das hier vorgestellte Ergebnis ist der erste Österreichische Blutdruckkonsens. Die Autoren und die beteiligten Fachgesellschaften sind davon überzeugt, daß es einer gemeinsamen nationalen Anstrengung bedarf, die Blutdruck-assoziierte Morbidität und Mortalität in unserem Land zu verringern.

A comprehensive policy for reducing sugar beverages for healthy life extension

The excessive consumption of sugar-sweetened beverages is a public health concern worldwide. Several clinical trials examining the effects of consuming sucrose or high-fructose corn syrup demonstrated the link between this consumption and increased risk factors for cardiometabolic diseases. In this issue of Environmental Health and Preventive Medicine, Li et al. examined the sugar-sweetened beverage consumption among undergraduate students and evaluated the relationship between this consumption and the "late" chronotype, sleep duration, and weight increase. They concluded that the sugar-sweetened beverage intake might mediate the associations among sleep duration, late chronotype, and weight gain and that the intake of sugar-sweetened beverages in the evening may be a risk factor for the development of overweight/obesity. A systematic review and meta-analysis of prospective cohort studies and randomized controlled trials provided evidence that the consumption of sugar-sweetened beverages promotes weight gain in both children and adults. The World Health Organization guideline highly recommends reducing the intake of sugars to less than 10% of one's total energy intake. The Dietary Approaches to Stop Hypertension diet and the Mediterranean diet were shown to help individuals refrain from sweets and sugar-containing beverages. A global evaluation revealed how much disability during accumulated lifetime hours is due to sugar-sweetened beverages. Interventions are necessary, but many individuals find it quite difficult to reduce or eliminate their high intake of sugar-sweetened beverages. The taxation of sugar-sweetened beverages was demonstrated to have a significant positive influence on individuals' planned purchases and the probability of the purchase of healthy beverages. Western countries are working on the social regulation of sugar-sweetened beverages, but Japan has not implemented any similar regulations. The social regulation of sugar-sweetened beverages is necessary to stop the increase of diabetes morbidity and the increase in dementia that often accompanies this morbidity.