The effect of insulin on renal sodium metabolism. A review with clinical implications

Kidney Energetics and Cyst Burden in Autosomal Dominant Polycystic Kidney Disease: A Pilot Study

RATIONALE & OBJECTIVE

In this pilot study, we hypothesized that autosomal dominant polycystic kidney disease (ADPKD) is characterized by impaired kidney oxidative metabolism that associates with kidney size and cyst burden.

STUDY DESIGN

Cross-sectional study.

SETTING & PARTICIPANTS

Twenty adults with ADPKD (age, 31±6 years; 65% women; body mass index [BMI], 26.8 [22.7-30.4] kg/m2; estimated glomerular filtration rate [eGFR, 2021 CKD-EPI creatinine], 103±18mL/min/1.73m2; height-adjusted total kidney volume [HTKV], 731±370mL/m; Mayo classifications 1B [5%], 1C [42%], 1D [21%], and 1E [32%]) and 11 controls in normal weight category (NWC) (age, 25±3 years; 45% women; BMI, 22.5 [21.7-24.2] kg/m2; eGFR, 113±15mL/min/1.73m2; HTKV, 159±31mL/m) at the University of Colorado Anschutz Medical Campus.

PREDICTORS

ADPKD status (yes/no) and severity (Mayo classifications).

OUTCOME

HTKV and cyst burden by magnetic resonance imaging, kidney oxidative metabolism, and perfusion by 11C-acetate positron emission tomography/computed tomography, insulin sensitivity by hyperinsulinemic-euglycemic clamps (presented as ratio of M-value of steady state insulin concentration [M/I]).

ANALYTICAL APPROACH

For categorical variables, χ2/Fisher's exact tests, and for continuous variables t tests/Mann-Whitney U tests. Pearson correlation was used to estimate the relationships between variables.

RESULTS

Compared with NWC individuals, the participants with ADPKD exhibited lower mean±SD M/I ratio (0.586±0.205 vs 0.424±0.171 [mg/kg lean/min]/(μIU/mL), P=0.04), lower median cortical perfusion (1.93 [IQR, 1.80-2.09] vs 0.68 [IQR, 0.47-1.04] mL/min/g, P<0.001) and lower median total kidney oxidative metabolism (0.17 [IQR, 0.16-0.19] vs. 0.14 [IQR, 0.12-0.15] min-1, P=0.001) in voxel-wise models excluding cysts. HTKV correlated inversely with cortical perfusion (r: -0.83, P < 0.001), total kidney oxidative metabolism (r: -0.61, P<0.001) and M/I (r: -0.41, P = 0.03).

LIMITATIONS

Small sample size and cross-sectional design.

CONCLUSIONS

Adults with ADPKD and preserved kidney function exhibited impaired renal perfusion and kidney oxidative metabolism across a wide range of cysts and kidney enlargements.

FUNDING

Grants from government (National Institutes of Health, Centers for Disease Control and Prevention) and not-for-profit (JDRF) entities.

TRIAL REGISTRATION

Registered at ClinicalTrials.gov with study numbers NCT04407481 and NCT04074668.

PLAIN-LANGUAGE SUMMARY

In our study, we explored how a common genetic kidney condition, autosomal dominant polycystic kidney disease (ADPKD), relates to kidney metabolism. ADPKD leads to the growth of numerous cysts in the kidneys, which can impact their ability to work properly. We wanted to understand the kidneys' ability to process oxygen and blood flow in ADPKD. Our approach involved using advanced imaging techniques to observe kidney metabolism and blood flow in people with ADPKD compared with healthy individuals. We discovered that those with ADPKD had significant changes in kidney oxygen metabolism even when their kidney function was still normal. These findings are crucial as they provide deeper insights into ADPKD, potentially guiding future treatments to target these changes.

Effect of dapagliflozin in patients with diabetes and heart failure with mildly reduced or preserved ejection fraction according to background glucose-lowering therapy: A pre-specified analysis of the DELIVER trial

AIMS

Type 2 diabetes (T2D) and heart failure (HF) frequently coexist, but whether clinical outcomes and treatment effects of sodium-glucose cotransporter 2 inhibitors (SGLT2i) vary in relation to background glucose-lowering therapy (GLT) in this population is uncertain.

METHODS AND RESULTS

DELIVER randomized patients with HF and left ventricular ejection fraction (LVEF) >40% to dapagliflozin or placebo. The primary outcome was a composite of worsening HF (HF hospitalization or urgent HF visit) or cardiovascular death. In this pre-specified analysis of participants with T2D, treatment effects were assessed by number and class of background GLT(s). Of 3150 participants with T2D at baseline, 22.9% were on no GLT, 36.5% were treated with 1 GLT, and 40.6% with ≥2 GLTs. During follow-up (median: 2.3 years), treatment benefits of dapagliflozin (vs. placebo) on the primary outcome were consistent irrespective of the number of background GLTs (0 GLTs: hazard ratio [HR] 0.71, 95% confidence interval [CI] 0.50-1.00; 1 GLT: HR 1.04, 95% CI 0.80-1.34; ≥2 GLTs: HR 0.71, 95% CI 0.56-0.90; pinteraction = 0.59). Similar findings were observed among participants with (HR 0.73, 95% CI 0.59-0.92) and without background metformin use (HR 0.89, 95% CI 0.72-1.11; pinteraction = 0.22) and in participants with (HR 0.89, 95% CI 0.69-1.16) and without background insulin use (HR 0.78, 95% CI 0.65-0.95; pinteraction = 0.45). Dapagliflozin was well-tolerated irrespective of the number of background GLTs.

CONCLUSIONS

Dapagliflozin safely and consistently improved clinical outcomes among individuals with T2D and HF with LVEF >40% irrespective of the number and class of background GLTs, and the benefits were not influenced by concomitant metformin or insulin use. These data bolster contemporary guidelines supporting first-line SGLT2i among individuals with T2D and HF, irrespective of background GLT.

Reducing the Risk of Pre-Eclampsia in Women with Polycystic Ovary Syndrome Using a Combination of Pregnancy Screening, Lifestyle, and Medical Management Strategies

Polycystic ovary syndrome (PCOS) is a multisystem disorder that presents with a variety of phenotypes involving metabolic, endocrine, reproductive, and psychological symptoms and signs. Women with PCOS are at increased risk of pregnancy complications including implantation failure, miscarriage, gestational diabetes, fetal growth restriction, preterm labor, and pre-eclampsia (PE). This may be attributed to the presence of specific susceptibility features associated with PCOS before and during pregnancy, such as chronic systemic inflammation, insulin resistance (IR), and hyperandrogenism, all of which have been associated with an increased risk of pregnancy complications. Many of the features of PCOS are reversible following lifestyle interventions such as diet and exercise, and pregnant women following a healthy lifestyle have been found to have a lower risk of complications, including PE. This narrative synthesis summarizes the evidence investigating the risk of PE and the role of nutritional factors in women with PCOS. The findings suggest that the beneficial aspects of lifestyle management of PCOS, as recommended in the evidence-based international guidelines, extend to improved pregnancy outcomes. Identifying high-risk women with PCOS will allow targeted interventions, early-pregnancy screening, and increased surveillance for PE. Women with PCOS should be included in risk assessment algorithms for PE.

Diet-induced ketosis in adult patients with subacute acquired brain injury: a feasibility study

Background

Research in animal models on cerebral metabolism after brain injury highlights the potential benefits of ketosis in reducing secondary brain injury, but studies in humans are lacking.

Aim

This study aimed to examine if a 6-week ketogenic diet intervention with added medium-chain triglycerides (MCT) was feasible in adult patients with acquired brain injury in the subacute phase, whether ketosis could be achieved and maintained, and to what extent serious adverse reactions, adverse reactions, serious adverse events, and adverse events occured.

Methods

Patients ≥18 years of age diagnosed with subacute acquired brain injury and an expectation of hospitalisation ≥6 weeks were included in the intervention group. Patients not included in the intervention group were included in a standard care reference group. The intervention consisted of a ketogenic diet supplemented with MCT to obtain a plasma concentration of β-hydroxybutyrate (BHB) ≥0.5 mmol/L. Patients who were enterally fed were given KetoCal® 2.5:1 LQ MCT Multi Fiber (Nutricia A/S, Allerød, Denmark), supplemented with Liquigen® (Nutricia A/S, Allerød, Denmark). Patients consuming oral nutrition were given KetoCal® 2.5:1 LQ MCT Multi Fiber supplemented with Liquigen®, in addition to ketogenic meals.

Results

During a 13-week inclusion period, 12 of 13 eligible patients (92% [95% CI: 67% to 99%]) were included in the intervention group, and 17 of 18 excluded patients (94% [95% CI: 74% to 99%]) were included in the reference group. Eight patients (67%) completed the 6-week intervention. It took a median of 1 day to achieve ketosis from starting a 100% MCT ketogenic diet, and it was maintained for 97% of the intervention period after ketosis was obtained. There were no serious adverse reactions to the MCT ketogenic diet, and patients experienced adverse reactions not considered serious in 9.5% of days with the intervention. The MCT ketogenic diet was accepted by patients on all intervention days, and in the two patients transitioning from enteral feeding to oral intake, there were no complications related to transitioning.

Conclusion

Intervention with MCT ketogenic diet is feasible and tolerated for 6 weeks in hospitalised adult patients with subacute acquired brain injury. Randomised controlled trials are needed to assess the benefits and harms of the MCT ketogenic diet and the effect on patients' recovery.Clinical trial registration: ClinicalTrials.gov, identifier [NCT04308577].

Association of a Combination of Sarcopenia and Type 2 Diabetes with Blood Parameters, Nutrient Intake, and Physical Activity: A Nationwide Population-Based Study

This study aimed to investigate the association of sarcopenia and type 2 diabetes (T2D) with blood parameters, nutrient intake, and physical activity in older Korean adults. We divided 2952 participants into four groups: sarcopenic diabetes (SD), sarcopenia alone (S), diabetes alone (D), and non-sarcopenia and non-diabetes (NSND). Sarcopenia was defined by the appendicular skeletal muscle mass index, and T2D by fasting glucose levels or ongoing treatment. Blood samples were collected after an 8-h fast. Nutrient intake was assessed using a 24-h recall; physical activity was evaluated using a questionnaire. Compared with those in the other groups, the men in the S and SD groups showed significantly lower hemoglobin and hematocrit levels; vitamin D levels in men and parathyroid hormone levels in women were significantly lower in the SD group. Total energy, protein, and carbohydrate intakes were significantly lower in the SD and S groups than those in the D and NSND groups. Physical inactivity was significantly more common in the SD group (men: odds ratio, 1.61; women: odds ratio, 2.37) than in the NSND group. A combination of sarcopenia and diabetes as well as sarcopenia alone was associated with low levels of blood parameters, poor nutrient intake, and low physical activity.

Association between insulin resistance and uncontrolled hypertension and arterial stiffness among US adults: a population-based study

BACKGROUND

Prior research has established the correlation between insulin resistance (IR) and hypertension. While the association between triglyceride-glucose (TyG) index, a reliable surrogate marker of IR, and uncontrolled hypertension as well as arterial stiffness among individuals with hypertension remains undisclosed.

METHODS

In this study, a total of 8513 adults diagnosed with hypertension from the National Health and Nutrition Examination Survey 1999-2018 were included. The primary outcome of the study are arterial stiffness (represented with estimated pulse wave velocity, ePWV) and uncontrolled hypertension. Logistic regression model, subgroup analysis, restricted cubic spine, and smooth curve fitting curve were conducted to evaluate the association between the IR indicators and uncontrolled hypertension and arterial stiffness in individuals with hypertension.

RESULTS

Among included participants, the overall prevalence of uncontrolled hypertension was 54.3%. After adjusting for all potential covariates, compared with the first quartile of TyG index, the risk of uncontrolled hypertension increased about 28% and 49% for participants in the third quartile (OR, 1.28; 95% CI 1.06-1.52) and the fourth quartile (OR, 1.49; 95% CI 1.21-1.89) of TyG index, respectively. The higher OR of TyG index was observed in participants taking antihypertensive medication [fourth quartile versus first quartile (OR, 2.03; 95% CI 1.37-3.11)]. Meanwhile, we explored the potential association between TyG index and arterial stiffness and found that TyG index was significantly associated with increased arterial stiffness (β for ePWV, 0.04; 95% CI 0.00-0.08; P = 0.039). However, traditional IR indicator HOMA-IR showed no significant positive correlation to uncontrolled hypertension as well as arterial stiffness in US adults with hypertension.

CONCLUSION

Elevated levels of the TyG index were positive associated with prevalence of uncontrolled hypertension and arterial stiffness among US adults with hypertension.

The damaging duo: Obesity and excess dietary salt contribute to hypertension and cardiovascular disease

Hypertension is a primary risk factor for cardiovascular disease. Cardiovascular disease is the leading cause of death among adults worldwide. In this review, we focus on two of the most critical public health challenges that contribute to hypertension-obesity and excess dietary sodium from salt (i.e., sodium chloride). While the independent effects of these factors have been studied extensively, the interplay of obesity and excess salt overconsumption is not well understood. Here, we discuss both the independent and combined effects of excess obesity and dietary salt given their contributions to vascular dysfunction, autonomic cardiovascular dysregulation, kidney dysfunction, and insulin resistance. We discuss the role of ultra-processed foods-accounting for nearly 60% of energy intake in America-as a major contributor to both obesity and salt overconsumption. We highlight the influence of obesity on elevated blood pressure in the presence of a high-salt diet (i.e., salt sensitivity). Throughout the review, we highlight critical gaps in knowledge that should be filled to inform us of the prevention, management, treatment, and mitigation strategies for addressing these public health challenges.

The Ketogenic Diet and Cardiovascular Diseases

The most common and increasing causes of death worldwide are cardiovascular diseases (CVD). Taking into account the fact that diet is a key factor, it is worth exploring this aspect of CVD prevention and therapy. The aim of this article is to assess the potential of the ketogenic diet in the prevention and treatment of CVD. The article is a comprehensive, meticulous analysis of the literature in this area, taking into account the most recent studies currently available. The ketogenic diet has been shown to have a multifaceted effect on the prevention and treatment of CVD. Among other aspects, it has a beneficial effect on the blood lipid profile, even compared to other diets. It shows strong anti-inflammatory and cardioprotective potential, which is due, among other factors, to the anti-inflammatory properties of the state of ketosis, the elimination of simple sugars, the restriction of total carbohydrates and the supply of omega-3 fatty acids. In addition, ketone bodies provide "rescue fuel" for the diseased heart by affecting its metabolism. They also have a beneficial effect on the function of the vascular endothelium, including improving its function and inhibiting premature ageing. The ketogenic diet has a beneficial effect on blood pressure and other CVD risk factors through, among other aspects, weight loss. The evidence cited is often superior to that for standard diets, making it likely that the ketogenic diet shows advantages over other dietary models in the prevention and treatment of cardiovascular diseases. There is a legitimate need for further research in this area.

Implementation of the medical emergencies in eating disorders in adults guidance on non-specialist units

The Royal College of Psychiatrists recently published data showing an 84% increase in UK hospital admissions for eating disorders over the past 5 years, highlighting the importance of the college's new Medical Emergencies in Eating Disorders (MEED) guidance. This includes a 79% increase among adults, many of whom are admitted to general medical wards that do not have input from expert eating disorder services. Consequently, the multidisciplinary nutrition support team, nutrition specialist nurses and dietitians have a potentially vital role in implementing MEED to ensure that the appropriate nutritional, fluid and electrolyte management is in place for safe refeeding and avoidance of the potentially harmful underfeeding syndrome. Furthermore, the guidance includes special recommendations for the use of nasogastric feeding in eating disorder patients, which requires input from experts in this field, including specialist nurses and dietitians. This article focuses on the implementation of MEED on hospital wards that do not have input from specialist eating disorders services.

Dapagliflozin Improves Erythropoiesis and Iron Metabolism in Type 2 Diabetic Patients with Renal Anemia

Purpose

In this study, we examined the effects of dapagliflozin on changes in hematopoiesis, iron metabolism, and body composition indices in elderly type 2 diabetic patients with renal impairment and investigated the potential of dapagliflozin to treat renal anemia.

Patients and Methods

The participants were elderly type 2 diabetics with renal impairment, and the indices of diabetes management, hematopoiesis, iron metabolism, and body composition were compared before and after dapagliflozin treatment.

Results

Fourteen subjects were given dapagliflozin 5 mg once daily for 12 weeks, three of whom had eligibility criteria deviations, such as serum ferritin <50 ng/mL. For this purpose, 14 subjects were analyzed as full analysis set (FAS) and 11 as per-protocol set (PPS). FAS analysis revealed that dapagliflozin had no effect on hemoglobin A1c after 12 weeks but significantly decreased body mass index, significantly increased hemoglobin, hematocrit, and red blood cell count, significantly decreased log ferritin level only of iron metabolism index, and no important change in body water content. PPS analysis, on the other hand, revealed that dapagliflozin 12-week treatment showed a significant decrease in log hepcidin, serum iron, and transferrin saturation.

Conclusion

These findings suggest that a 12-week course of dapagliflozin causes an increase in hemoglobin levels due to its hematopoietic effects in elderly type 2 diabetics with renal impairment, but that these effects may be independent of body water loss and iron metabolism improvement.

Cord Blood Insulin Concentration and Hypertension Among Children and Adolescents Enrolled in a US Racially Diverse Birth Cohort

BACKGROUND

Although insulin resistance is closely related to hypertension, the debate continues as to whether insulin resistance is a cause or a consequence of hypertension. This study investigated the associations of cord blood insulin concentration with blood pressure (BP) and hypertension in childhood and adolescence.

METHODS

This study included 951 children enrolled from 1998 to 2012 and followed from birth onwards at the Boston Medical Center, Boston, MA. Cord blood insulin concentration was measured using a sandwich immunoassay. Hypertension in childhood and adolescence was defined based on the 2017 American Academy of Pediatrics Clinical Practice Guidelines.

RESULTS

The median (interquartile range) for cord blood insulin concentration was 12.1 (7.2-19.0) µIU/mL. The age range of BP measurements was 3 to 18 years (median, 10.6 years). Cord blood insulin concentration was positively associated with systolic and diastolic BP as well as the risk of hypertension at age 3 to 18 years. Compared with the lowest tertile of cord blood insulin concentration, the top tertile insulin concentration was associated with a 5.18 (95% CI, 1.97-8.39) percentile increase in systolic BP, 4.29 (95% CI, 1.74-6.84) percentile increase in diastolic BP, and 1.62-fold (95% CI, 1.27-2.08) higher risk of hypertension. The association between insulin and hypertension was stronger among children born preterm (P for interaction=0.048). Furthermore, preterm birth and childhood overweight or obesity enhanced the associations.

CONCLUSIONS

Our results suggest that elevated insulin concentration at birth plays a critical role in the early life origins of hypertension and support the hypothesis implicating insulin resistance in the etiology of hypertension.

Altered dietary salt intake for preventing diabetic kidney disease and its progression

BACKGROUND

There is strong evidence that our current consumption of salt is a major factor in the development of increased blood pressure (BP) and that a reduction in our salt intake lowers BP, whether BP levels are normal or raised initially. Effective control of BP in people with diabetes lowers the risk of strokes, heart attacks and heart failure and slows the progression of chronic kidney disease (CKD) in people with diabetes. This is an update of a review first published in 2010.

OBJECTIVES

To evaluate the effect of altered salt intake on BP and markers of cardiovascular disease and of CKD in people with diabetes.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 31 March 2022 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register were identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of altered salt intake in individuals with type 1 and type 2 diabetes. Studies were included when there was a difference between low and high sodium intakes of at least 34 mmol/day.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed studies and resolved differences by discussion. We calculated mean effect sizes as mean difference (MD) and 95% confidence intervals (CI) using the random-effects model. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

Thirteen RCTs (313 participants), including 21 comparisons (studies), met our inclusion criteria. One RCT (two studies) was added to this review update. Participants included 99 individuals with type 1 diabetes and 214 individuals with type 2 diabetes. Two RCTs (four studies) included some participants with reduced overall kidney function. The remaining studies either reported that participants with reduced glomerular filtration rate (GFR) were excluded from the study or only included participants with microalbuminuria and normal GFR. Five studies used a parallel study design, and 16 used a cross-over design. Studies were at high risk of bias for most criteria. Random sequence generation and allocation concealment were adequate in only three and two studies, respectively. One study was at low risk of bias for blinding of participants and outcome assessment, but no studies were at low risk for selective reporting. Twelve studies reported non-commercial funding sources, three reported conflicts of interest, and eight reported adequate washout between interventions in cross-over studies. The median net reduction in 24-hour urine sodium excretion (24-hour UNa) in seven long-term studies (treatment duration four to 12 weeks) was 76 mmol (range 51 to 124 mmol), and in 10 short-term studies (treatment duration five to seven days) was 187 mmol (range 86 to 337 mmol). Data were only available graphically in four studies. In long-term studies, reduced sodium intake may lower systolic BP (SBP) by 6.15 mm Hg (7 studies: 95% CI -9.27 to -3.03; I² = 12%), diastolic BP (DBP) by 3.41 mm Hg (7 studies: 95% CI -5.56 to -1.27; I² = 41%) and mean arterial pressure (MAP) by 4.60 mm Hg (4 studies: 95% CI -7.26 to -1.94; I² = 28%). In short-term studies, low sodium intake may reduce SBP by 8.43 mm Hg (5 studies: 95% CI -14.37 to -2.48; I² = 88%), DBP by 2.95 mm Hg (5 studies: 95% CI -4.96 to -0.94; I² = 70%) and MAP by 2.37 mm Hg (9 studies: 95% CI -4.75 to -0.01; I² = 65%). There was considerable heterogeneity in most analyses but particularly among short-term studies. All analyses were considered to be of low certainty evidence. SBP, DBP and MAP reductions may not differ between hypertensive and normotensive participants or between individuals with type 1 or type 2 diabetes. In hypertensive participants, SBP, DBP and MAP may be reduced by 6.45, 3.15 and 4.88 mm Hg, respectively, while in normotensive participants, they may be reduced by 8.43, 2.95 and 2.15 mm Hg, respectively (all low certainty evidence). SBP, DBP and MAP may be reduced by 7.35, 3.04 and 4.30 mm Hg, respectively, in participants with type 2 diabetes and by 7.35, 3.20, and 0.08 mm Hg, respectively, in participants with type 1 diabetes (all low certainty evidence). Eight studies provided measures of urinary protein excretion before and after salt restriction; four reported a reduction in urinary albumin excretion with salt restriction. Pooled analyses showed no changes in GFR (12 studies: MD -1.87 mL/min/1.73 m², 95% CI -5.05 to 1.31; I² = 32%) or HbA1c (6 studies: MD -0.62, 95% CI -1.49 to 0.26; I² = 95%) with salt restriction (low certainty evidence). Body weight was reduced in studies lasting one to two weeks but not in studies lasting for longer periods (low certainty evidence). Adverse effects were reported in only one study; 11% and 21% developed postural hypotension on the low-salt diet and the low-salt diet combined with hydrochlorothiazide, respectively.

AUTHORS' CONCLUSIONS

This systematic review shows an important reduction in SBP and DBP in people with diabetes with normal GFR during short periods of salt restriction, similar to that obtained with single drug therapy for hypertension. These data support the international recommendations that people with diabetes with or without hypertension or evidence of kidney disease should reduce salt intake to less than 5 g/day (2 g sodium).

Pharmacotherapy of type 2 diabetes: An update and future directions

Type 2 diabetes (T2D) is a widely prevalent disease with substantial economic and social impact for which multiple conventional and novel pharmacotherapies are currently available; however, the landscape of T2D treatment is constantly changing as new therapies emerge and the understanding of currently available agents deepens. This review aims to provide an updated summary of the pharmacotherapeutic approach to T2D. Each class of agents is presented by mechanism of action, details of administration, side effect profile, cost, and use in certain populations including heart failure, non-alcoholic fatty liver disease, obesity, chronic kidney disease, and older individuals. We also review targets of novel therapeutic T2D agent development. Finally, we outline an up-to-date treatment approach that starts with identification of an individualized goal for glycemic control then selection, initiation, and further intensification of a personalized therapeutic plan for T2D.

Youth versus adult-onset type 2 diabetic kidney disease: Insights into currently known structural differences and the potential underlying mechanisms

Type 2 diabetes (T2D) is a global health pandemic with significant humanitarian, economic, and societal implications, particularly for youth and young adults who are experiencing an exponential rise in incident disease. Youth-onset T2D has a more aggressive phenotype than adult-onset T2D, and this translates to important differences in rates of progression of diabetic kidney disease (DKD). We hypothesize that youth-onset DKD due to T2D may exhibit morphometric, metabolic, and molecular characteristics that are distinct from adult-onset T2D and develop secondary to inherent differences in renal energy expenditure and substrate metabolism, resulting in a central metabolic imbalance. Kidney structural changes that are evident at the onset of puberty also serve to exacerbate the organ’s baseline high rates of energy expenditure. Additionally, the physiologic state of insulin resistance seen during puberty increases the risk for kidney disease and is exacerbated by both concurrent diabetes and obesity. A metabolic mismatch in renal energetics may represent a novel target for pharmacologic intervention, both for prevention and treatment of DKD. Further investigation into the underlying molecular mechanisms resulting in DKD in youth-onset T2D using metabolomics and RNA sequencing of kidney tissue obtained at biopsy is necessary to expand our understanding of early DKD and potential targets for therapeutic intervention. Furthermore, large-scale clinical trials evaluating the duration of kidney protective effects of pharmacologic interventions that target a metabolic mismatch in kidney energy expenditure are needed to help mitigate the risk of DKD in youth-onset T2D.

Time-Restricted Eating in Metabolic Syndrome-Focus on Blood Pressure Outcomes

PURPOSE OF THE REVIEW

Time-restricted eating (TRE) is a promising dietary intervention for weight loss and improvement of cardiometabolic risk factors. We aim to provide a critical review of blood pressure outcomes reported in clinical TRE studies in adults with metabolic syndrome, in the context of the proposed mechanisms that underlie the relationship between timing of eating and blood pressure.

RECENT FINDINGS

Clinical TRE studies report mixed results pertaining to blood pressure outcomes, likely due to significant heterogeneity in study design and TRE protocols. Mechanistically, TRE's metabolic benefits have been speculated to be mediated by alignment of meal timing with circadian regulation of metabolic processes and/or enhancement of catabolism as a result of prolonging the fasting period. TRE protocols that start and end earlier appear to have more pronounced blood pressure lowering effects. Blood pressure also tends to be lower with narrower eating windows. Concurrent weight loss is not consistently linked to blood pressure reduction, while lower insulin levels may be an important factor for blood pressure reduction. Notably, no published studies have reported 24-h blood pressure profiles or data on blood pressure variability. Blood pressure has only been examined in limited TRE studies, measured at a single time point. Given the clinical relevance of blood pressure's diurnal variability and the mechanistic evidence underlying timing of eating and blood pressure effects, more studies are needed to investigate TRE's effects on the diurnal variability of blood pressure.

Use of Glucose-Lowering Agents in Diabetes and CKD

Diabetes is the most common cause of kidney failure worldwide. Patients with diabetes and chronic kidney disease (CKD) are also at markedly higher risk of cardiovascular disease, particularly heart failure (HF), and death. Through the processes of gluconeogenesis and glucose reabsorption, the kidney plays a central role in glucose homeostasis. Insulin resistance is an early alteration observed in CKD, worsened by the frequent presence of hypertension, obesity, and ongoing chronic inflammation, and oxidative stress. Management of diabetes in moderate to severe CKD warrants special consideration because of changes in glucose and insulin homeostasis and altered metabolism of glucose-lowering therapies. Kidney failure and initiation of kidney replacement therapy by dialysis adds to management complexity by further limiting therapeutic options, and predisposing individuals to hypoglycemia and hyperglycemia. Glycemic goals should be individualized, considering CKD severity, presence of macrovascular and microvascular complications, and life expectancy. A general hemoglobin A1c (HbA1c) goal of approximately 7% may be appropriate in earlier stages of CKD, with more relaxed targets often appropriate in later stages. Use of sodium glucose cotransporter2 (SGLT2) inhibitors and glucagon like peptide-1 receptor agonists (GLP-1RAs) meaningfully improves kidney and heart outcomes for patients with diabetes and CKD, irrespective of HbA1c targets, and are now part of guideline-directed medical therapy in this high-risk population. Delivery of optimal care for patients with diabetes and CKD will require collaboration across health care specialties and disciplines.

Adipose tissue insulin resistance predicts the incidence of hypertension: The Hiroshima Study on Glucose Metabolism and Cardiovascular Diseases

We investigated the association of adipose tissue insulin resistance with blood pressure and hypertension incidence, comparing it with hepatic and skeletal muscle insulin resistance. The cross-sectional analysis included 6892 general health checkup examinees (mean age: 69.3 years; 51.3% women and 48.7% men) who had no cardiovascular disease. Of those, 3948 normotensive participants (mean age: 68.4 years; 54.8% women and 45.2% men) were enrolled in the retrospective cohort analysis. The adipose insulin resistance index (Adipo-IR) was calculated as the product of fasting serum insulin and free fatty acid levels. A high adipo-IR, high homeostasis model assessment of insulin resistance (HOMA-IR), and low Matsuda index were indicated based on the optimal cutoff values in a receiver operating characteristic curve analysis. Adipo-IR (β = 0.096, P < 0.001), HOMA-IR (β = 0.052, P < 0.001), and Matsuda index (β = -0.055, P < 0.001) were associated with systolic blood pressure in the cross-sectional analysis. Over a mean 5.3-year follow-up period, 1310 participants developed hypertension. A high adipo-IR (adjusted OR, 1.29; 95% CI, 1.11-1.51), but not HOMA-IR or Matsuda index, was significantly associated with the incidence of hypertension. Moreover, the combination of high adipo-IR with high HOMA-IR or low Matsuda index showed no higher odds of hypertension than a high adipo-IR alone. These results suggest that insulin resistance is associated with blood pressure control regardless of the tissue in which it occurs; however, the risk of hypertension is determined by insulin resistance in adipose tissue rather than in liver or muscle tissue.

Novel perspectives of sodium handling in type 2 diabetes mellitus

INTRODUCTION

As a key regulator of body water, sodium homeostasis forms an essential component of human physiology. Type 2 Diabetes Mellitus (T2D)-associated sodium overload stems from chronic renal retention of sodium, contributing toward the development of adverse cardiovascular sequelae.

AREAS COVERED

Our traditional model of sodium regulation invokes two compartments: extracellular fluid (ECF [plasma and interstitial fluid]) and intracellular fluid (ICF). Data from the Mars program reveal inconsistencies with this two-space model, including mismatches between net body sodium and water. Recent data utilizing 23Na magnetic resonance imaging (MRI) show a preponderance of bound sodium within human dermis, consistent with a third space repository and providing compelling evidence to support a three-space model in which dermal sodium binding facilitates sodium homeostasis within the ECF and ICF. This buffer is impaired in T2D, with diminishment of dermal bound sodium that may promote deleterious sequelae of sodium overload within the ECF and ICF.

EXPERT OPINION

Future studies should focus on novel therapeutic opportunities for sodium regulation in T2D and other conditions of sodium dysregulation. The ratio of free:bound dermal sodium (reflecting sodium storage capacity) could be utilized as a clinical biomarker for salt and water balance, to improve diagnostic accuracy and facilitate clinical decision-making.

Tolerability of Sacubitril/Valsartan in Patients With Advanced Heart Failure: Analysis of the LIFE Trial Run-In

BACKGROUND

The LIFE (LCZ696 In Hospitalized Advanced Heart FailurE) trial, which evaluated sacubitril/valsartan in patients with advanced heart failure (HF) with reduced ejection fraction and recent New York Heart Association functional class IV symptomatology, did not require tolerance to a renin angiotensin system antagonist before initiating sacubitril/valsartan, thus affording an opportunity to study the tolerability of sacubitril/valsartan in advanced HF with reduced ejection fraction.

OBJECTIVES

The goal of this analysis of the LIFE trial is to characterize the tolerability of initiating sacubitril/valsartan in patients with chronic advanced HF with reduced ejection fraction.

METHODS

In the LIFE trial, 445 subjects with advanced HF entered an unblinded run-in period of 3-7 days with sacubitril/valsartan 24/26 mg twice a day. The authors compared characteristics of subjects completing and failing run-in, performed multivariable analysis of clinical parameters associated with run-in failure, and developed a predictive model for short-term intolerance to sacubitril/valsartan.

RESULTS

Of 445 subjects entering run-in, 73 (18%) were intolerant of sacubitril/valsartan. Reasons for intolerance included systolic blood pressure <90 mm Hg (59%), symptoms of hypotension/dizziness with systolic blood pressure >90 mm Hg (19%), and renal dysfunction (creatinine >2.0 mg/dL) (12%). Multivariable predictors of intolerance included lower mean arterial pressure, lower serum chloride, presence of an implantable cardioverter-defibrillator and/or cardiac resynchronization device, moderate or greater mitral regurgitation, nonuse of angiotensin-converting enzyme inhibitor or angiotensin receptor blocker at the screening visit, and use of insulin at screening. Subjects with 4 or more predictors had a 48.9% probability of sacubitril/valsartan intolerance.

CONCLUSIONS

Intolerance to low doses of sacubitril/valsartan is common in patients with advanced chronic HF with reduced ejection fraction and may be predicted by the presence of certain risk factors. (EntrestoTM [LCZ696] in Advanced Heart Failure [LIFE Study] [HFN-LIFE] NCT02816736).

Impact of insulin therapy on outcomes of diabetic patients with heart failure: A systematic review and meta-analysis

OBJECTIVE

To compare clinical outcomes in diabetic patients with heart failure managed by insulin with those managed by non-insulin (oral hypoglycemic agents and/or lifestyle modification) based therapy.

METHODS

PubMed and Scopus databases were searched for studies conducted on diabetic patients with heart failure. Studies were to compare outcomes of patients managed by insulin versus non-insulin therapies.

RESULTS

15 studies were included. Compared to those who were managed using non-insulin therapy, insulin-treated patients had increased risk of all-cause mortality (RR 1.46, 95% CI: 1.14, 1.88) and cardiovascular specific mortality (RR 1.62, 95% CI: 1.33, 1.96). Those managed using insulin also had increased risk of hospitalization (RR 1.45, 95% CI: 1.09, 1.93) and readmission (RR 1.49, 95% CI: 1.32, 1.67). There was no additional risk for stroke (RR 1.07, 95% CI: 0.91, 1.27) or myocardial infarction (MI) (RR 1.10, 95% CI: 0.96, 1.27) between the two groups of patients.

CONCLUSIONS

Receipt of insulin among diabetic patients with heart failure was associated with an increased risk of mortality, hospitalization and readmission compared to management using oral hypoglycemic agents and/or lifestyle modification. Such patients should be closely monitored for any adverse events.

Comparison of Fasting Insulin Level, Homeostatic Model of Insulin Resistance, and Lipid Levels between Patients with Primary Hypertension and Normotensive Subjects

BACKGROUND

Hyperinsulinemia and insulin resistance occurs in obese patients with primary hypertension independent of diabetes and obesity. This study was aimed at assessing serum fasting insulin levels, the homeostatic model assessment for insulin resistance (HOMA-IR), and serum lipid levels in non-obese patients with primary hypertension when compared to normotensive subjects.

METHODS

This observational study comprised 100 patients over 18 years of age, divided into two groups. The hypertensive group comprised non-obese patients with primary hypertension (n=50); the normotensive group comprised normotensive age- and sex-matched individuals (n=50). Patients with diabetes, impaired fasting glucose, obesity, and other causative factors of insulin resistance were excluded from the study. Serum fasting insulin levels and fasting lipid profiles were measured, and insulin resistance was calculated using HOMA-IR. These data were compared between the two groups. Pearson's correlation coefficient was used to assess the extent of a linear relationship between HOMA-IR and to evaluate the association between HOMA-IR and systolic and diastolic blood pressures.

RESULTS

Mean serum fasting insulin levels (mIU/L), mean HOMA-IR values, and fasting triglyceride levels (mg/dL) were significantly higher in the hypertensive versus normotensive patients (10.32 versus 6.46, P<0.001; 1.35 versus 0.84, P<0.001; 113.70 versus 97.04, P=0.005, respectively). The HOMA-IR levels were associated with systolic blood pressure (r value 0.764, P=0.0005).

CONCLUSION

We observed significantly higher fasting insulin levels, serum triglyceride levels, and HOMA-IR reflecting hyperinsulinemia and possibly an insulin-resistant state among primary hypertension patients with no other causally linked factors for insulin resistance. We observed a significant correlation between systolic blood pressure and HOMA-IR.

Role of Blood Pressure Responses to Exercise and Vascular Insulin Sensitivity with Nocturnal Blood Pressure Dipping in Metabolic Syndrome

INTRODUCTION

Nocturnal systolic blood pressure (SBP) dipping is independently related to cardiovascular disease risk, but it is unclear if vascular insulin sensitivity associates with SBP dipping in patients with metabolic syndrome (MetS).

METHODS

Eighteen adults with MetS (ATP III criteria 3.3 ± 0.6; 53.2 ± 6.5 years; body mass index 35.8 ± 4.5 kg/m2) were categorized as "dippers" (≥10% change in SBP; n = 4 F/3 M) or "non-dippers" (<10%; n = 9 F/2 M). Twenty-four-hour ambulatory blood pressure was recorded to assess SBP dipping. A euglycemic-hyperinsulinemic clamp (40 mU/m2/min, 90 mg/dL) with ultrasound (flow mediated dilation) was performed to test vascular insulin sensitivity. A graded, incremental exercise test was conducted to estimate sympathetic activity. Heart rate (HR) recovery after exercise was then used to determine parasympathetic activity. Metabolic panels and body composition (DXA) were also tested.

RESULTS

Dippers had greater drops in SBP (16.63 ± 5.2 vs. 1.83 ± 5.6%, p < 0.01) and experienced an attenuated rise in both SBPslope (4.7 ± 2.3 vs. 7.2 ± 2.5 mm Hg/min, p = 0.05) and HRslope to the incremental exercise test compared to non-dippers (6.5 ± 0.9 vs. 8.2 ± 1.7 bpm/min, p = 0.03). SBP dipping correlated with higher insulin-stimulated flow-mediated dilation (r = 0.52, p = 0.03), although the relationship was no longer significant after covarying for HRslope (r = 0.42, p = 0.09).

CONCLUSION

Attenuated rises in blood pressure and HR to exercise appear to play a larger role than vascular insulin sensitivity in SBP dipping in adults with MetS.

Drug-Related Lymphedema: Mysteries, Mechanisms, and Potential Therapies

The lymphatic circulation is an important component of the circulatory system in humans, playing a critical role in the transport of lymph fluid containing proteins, white blood cells, and lipids from the interstitial space to the central venous circulation. The efficient transport of lymph fluid critically relies on the rhythmic contractions of collecting lymph vessels, which function to "pump" fluid in the distal to proximal direction through the lymphatic circulation with backflow prevented by the presence of valves. When rhythmic contractions are disrupted or valves are incompetent, the loss of lymph flow results in fluid accumulation in the interstitial space and the development of lymphedema. There is growing recognition that many pharmacological agents modify the activity of ion channels and other protein structures in lymph muscle cells to disrupt the cyclic contraction and relaxation of lymph vessels, thereby compromising lymph flow and predisposing to the development of lymphedema. The effects of different medications on lymph flow can be understood by appreciating the intricate intracellular calcium signaling that underlies the contraction and relaxation cycle of collecting lymph vessels. For example, voltage-sensitive calcium influx through long-lasting ("L-type") calcium channels mediates the rise in cytosolic calcium concentration that triggers lymph vessel contraction. Accordingly, calcium channel antagonists that are mainstay cardiovascular medications, attenuate the cyclic influx of calcium through L-type calcium channels in lymph muscle cells, thereby disrupting rhythmic contractions and compromising lymph flow. Many other classes of medications also may contribute to the formation of lymphedema by impairing lymph flow as an off-target effect. The purpose of this review is to evaluate the evidence regarding potential mechanisms of drug-related lymphedema with an emphasis on common medications administered to treat cardiovascular diseases, metabolic disorders, and cancer. Additionally, although current pharmacological approaches used to alleviate lymphedema are largely ineffective, efforts are mounting to arrive at a deeper understanding of mechanisms that regulate lymph flow as a strategy to identify novel anti-lymphedema medications. Accordingly, this review also will provide information on studies that have explored possible anti-lymphedema therapeutics.

Effects of SGLT2 inhibitors on haematocrit and haemoglobin levels and the associated cardiorenal benefits in T2DM patients: A meta-analysis

To explore the effect and magnitude of effect of sodium-glucose cotransporter-2 (SGLT2) inhibitors on haematocrit and haemoglobin and the related cardiorenal benefits in patients with type 2 diabetes mellitus (T2DM), PubMed, Web of Science, CENTRAL and EMBASE were searched to identify eligible trials. Weighted mean differences (WMDs) with 95% confidence intervals (CIs) were calculated using a random-effects model. Seventy-eight studies were included in the meta-analysis. SGLT2 inhibitors significantly increased haematocrit and haemoglobin levels compared with control (total WMD 2.27% [95% CI 2.08, 2.47] and 6.20 g/L [95% CI 5.68, 6.73], respectively). Except for dapagliflozin (p = 0.000), no notable dose-dependent relationship was revealed for other SGLT2 inhibitors. The effect could be sustained or even slightly increased with long-term therapy (coef. =0.009, 95% CI [0.005, 0.013], p = 0.000). In subgroup analyses, haematocrit elevation increased with higher body mass index (BMI). A greater haematocrit elevation could be observed in white patients or when compared with active controls. In conclusion, SGLT2 inhibitors increased haematocrit and haemoglobin levels in T2DM patients. Changes in haematocrit and haemoglobin seem to be surrogate markers of improvement in renal metabolic stress, and important mediators involved in cardiorenal protection.

Behavioral Characteristics and Self-Reported Health Status among 2029 Adults Consuming a "Carnivore Diet"

BACKGROUND

The "carnivore diet," based on animal foods and excluding most or all plant foods, has attracted recent popular attention. However, little is known about the health effects and tolerability of this diet, and concerns for nutrient deficiencies and cardiovascular disease risk have been raised.

OBJECTIVES

We obtained descriptive data on the nutritional practices and health status of a large group of carnivore diet consumers.

METHODS

A social media survey was conducted 30 March-24 June, 2020 among adults self-identifying as consuming a carnivore diet for ≥6 mo. Survey questions interrogated motivation, dietary intake patterns, symptoms suggestive of nutritional deficiencies or other adverse effects, satisfaction, prior and current health conditions, anthropometrics, and laboratory data.

RESULTS

A total of 2029 respondents (median age: 44 y, 67% male) reported consuming a carnivore diet for 14 mo (IQR: 9-20 mo), motivated primarily by health reasons (93%). Red meat consumption was reported as daily or more often by 85%. Under 10% reported consuming vegetables, fruits, or grains more often than monthly, and 37% denied vitamin supplement use. Prevalence of adverse symptoms was low (<1% to 5.5%). Symptoms included gastrointestinal (3.1%-5.5%), muscular (0.3%-4.0%), and dermatologic (0.1%-1.9%). Participants reported high levels of satisfaction and improvements in overall health (95%), well-being (66%-91%), various medical conditions (48%-98%), and median [IQR] BMI (in kg/m2) (from 27.2 [23.5-31.9] to 24.3 [22.1-27.0]). Among a subset reporting current lipids, LDL-cholesterol was markedly elevated (172 mg/dL), whereas HDL-cholesterol (68 mg/dL) and triglycerides (68 mg/dL) were optimal. Participants with diabetes reported benefits including reductions in median [IQR] BMI (4.3 [1.4-7.2]), glycated hemoglobin (0.4% [0%-1.7%]), and diabetes medication use (84%-100%).

CONCLUSIONS

Contrary to common expectations, adults consuming a carnivore diet experienced few adverse effects and instead reported health benefits and high satisfaction. Cardiovascular disease risk factors were variably affected. The generalizability of these findings and the long-term effects of this dietary pattern require further study.

Female Sex and Angiotensin-Converting Enzyme (ACE) Insertion/Deletion Polymorphism Amplify the Effects of Adiposity on Blood Pressure

The pathophysiological link between adiposity and blood pressure is not completely understood, and evidence suggests an influence of sex and genetic determinants. We aimed to identify the relationship between adiposity and blood pressure, independent of a robust set of lifestyle and metabolic factors, and to examine the modulating role of sex and Angiotensin-Converting Enzyme (ACE) insertion/deletion (I/D) polymorphisms. In the Relationship Between Insulin Sensitivity and Cardiovascular Disease (RISC) study cohort, 1211 normotensive individuals, aged 30 to 60 years and followed-up after 3.3 years, were characterized for lifestyle and metabolic factors, body composition, and ACE genotype. Body mass index (BMI) and waist circumference (WC) were independently associated with mean arterial pressure, with a stronger relationship in women than men (BMI: r=0.40 versus 0.30; WC: r=0.40 versus 0.30, both P<0.01) and in individuals with the ID and II ACE genotypes in both sexes (P<0.01). The associations of BMI and WC with mean arterial pressure were independent of age, sex, lifestyle, and metabolic variables (standardized regression coefficient=0.17 and 0.18 for BMI and WC, respectively) and showed a significant interaction with the ACE genotype only in women (P=0.03). A 5 cm larger WC at baseline increased the risk of developing hypertension at follow-up only in women (odds ratio, 1.56 [95% CI, 1.15-2.10], P=0.004) and in II genotype carriers (odds ratio, 1.87 [95% CI, 1.09-3.20], P=0.023). The hypertensive effect of adiposity is more pronounced in women and in people carrying the II variant of the ACE genotype, a marker of salt sensitivity.

Retrospective cohort study of changes in estimated glomerular filtration rate for patients prescribed a low carb diet

PURPOSE OF REVIEW

Obesity and diabetes contribute to chronic kidney disease (CKD) and accelerate the loss of kidney function. Low carbohydrate diets (LCDs) are associated with weight loss and improved diabetes control. Compared to the typical Western diet, LCDs contain more protein, so individuals with CKD are not included in studies of LCDs. Therefore, there are no studies of LCDs for weight loss and their effects on kidney function.

RECENT FINDINGS

Obesity, hyperglycemia, and hyperinsulinemia can be detrimental to kidney function. LCDs may improve kidney function in patients with obesity and diabetes because they are associated with weight loss, improve blood sugar control, and decrease endogenous insulin production and exogenous insulin requirements.

SUMMARY

In this study, for patients with mildly reduced and moderately to severely reduced kidney function who were prescribed an LCD, their estimated glomerular filtration rate (eGFR) was either unchanged or improved. For those with normal or elevated eGFR, their kidney function was slightly decreased. For those without diabetes, greater weight loss was associated with improved eGFR. Future studies should prospectively measure low carbohydrate dietary adherence and physical activity and directly measure changes in GFR and albuminuria for participants with CKD before and during that diet.

The effects of insulin therapy on maternal blood pressure and weight in women with gestational diabetes mellitus

Background

Although insulin therapy achieves effective glycemic control, it may aggravate hyperinsulinemia. Nonetheless the benefits of insulin as first-line treatment for women with GDM are controversial. This work aimed to investigate the effect of insulin on maternal GDM.

Methods

This retrospective cohort study recruited 708 women with GDM of whom 616 underwent lifestyle intervention and 92 were prescribed insulin therapy. Differences in variables between the two groups were analyzed by univariate analysis and multivariate analysis. Propensity score matching was used to control for age, pre-pregnancy BMI, time and BP at GDM diagnosis, and family history of diabetes and hypertension. Paired sample test was applied to evaluate the changes in BP after intervention in the two groups of women.

Results

There was no significant difference in mode of delivery, newborn weight or incidence of macrosomia between women prescribed insulin and those who adopted lifestyle modifications. Insulin therapy was associated with a slight increase in maternal weight compared with the lifestyle intervention group and was attributed to short-term treatment (about 12 weeks). In addition, insulin therapy remarkably increased maternal blood pressure, an effect that persisted after matching age, pre-pregnancy BMI, time and BP at GDM diagnosis, and family history of diabetes and hypertension. Between commencing insulin therapy and delivery, systolic blood pressure significantly increased by 6mmHg (P = 0.015) and diastolic blood pressure by 9 mmHg (P < 0.001). Increase in BP was significantly higher in the insulin group compared with the lifestyle intervention group (P < 0.001). Logistic regression analysis with enter selection confirmed that insulin therapy was closely correlated with development of gestational hypertension (GH).

Conclusions

This work suggested that short-term insulin therapy for GDM was associated with a slight increase in maternal weight but a significant risk of increasing maternal blood pressure.

Eating before bed and new-onset hypertension in a Japanese population: the Iki city epidemiological study of atherosclerosis and chronic kidney disease

The aim of this study was to determine the relationship between eating before bed and the development of hypertension in a general Japanese population. We conducted a population-based retrospective cohort study using annual health check-up data collected from the residents of Iki City, Nagasaki Prefecture, Japan. In total, 2930 participants without hypertension at baseline (mean age 57.0 years, male 42.8%) were included in the present analysis. Eating before bed was defined as eating within 2 h of bedtime. The outcome of this study was incident hypertension (blood pressure ≥140/90 mmHg or initiation of blood pressure-lowering medications). Multivariable-adjusted hazard ratios and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models. During an average follow-up of 4.5 years, 909 participants developed hypertension. The incidence (per 1000 person-years) of hypertension in the group of individuals who ate before bed was 82.8, whereas that in the group of individuals who did not eat before bed was 65.8. The association was significant even after adjusting for other risk factors, including age, sex, current smoking status, current alcohol intake, regular exercise, obesity, elevated blood pressure, diabetes mellitus, and dyslipidemia, with a hazard ratio of 1.23 (95% CI: 1.05-1.44) for the group of individuals who ate before bed compared with the group of individuals who did not eat before bed (P = 0.01 for trend). Eating before bed was correlated with a future risk of developing hypertension in the general Japanese population.

Alternative Dietary Patterns for Americans: Low-Carbohydrate Diets

The decades-long dietary experiment embodied in the Dietary Guidelines for Americans (DGA) focused on limiting fat, especially saturated fat, and higher carbohydrate intake has coincided with rapidly escalating epidemics of obesity and type 2 diabetes (T2D) that are contributing to the progression of cardiovascular disease (CVD) and other diet-related chronic diseases. Moreover, the lack of flexibility in the DGA as it pertains to low carbohydrate approaches does not align with the contemporary trend toward precision nutrition. We argue that personalizing the level of dietary carbohydrate should be a high priority based on evidence that Americans have a wide spectrum of metabolic variability in their tolerance to high carbohydrate loads. Obesity, metabolic syndrome, and T2D are conditions strongly associated with insulin resistance, a condition exacerbated by increased dietary carbohydrate and improved by restricting carbohydrate. Low-carbohydrate diets are grounded across the time-span of human evolution, have well-established biochemical principles, and are now supported by multiple clinical trials in humans that demonstrate consistent improvements in multiple established risk factors associated with insulin resistance and cardiovascular disease. The American Diabetes Association (ADA) recently recognized a low carbohydrate eating pattern as an effective approach for patients with diabetes. Despite this evidence base, low-carbohydrate diets are not reflected in the DGA. As the DGA Dietary Patterns have not been demonstrated to be universally effective in addressing the needs of many Americans and recognizing the lack of widely available treatments for obesity, metabolic syndrome, and T2D that are safe, effective, and sustainable, the argument for an alternative, low-carbohydrate Dietary Pattern is all the more compelling.

Associations of Insulin Resistance With Systolic and Diastolic Blood Pressure: A Study From the HCHS/SOL

[Figure: see text].

The Aggressive Diabetic Kidney Disease in Youth-Onset Type 2 Diabetes: Pathogenetic Mechanisms and Potential Therapies

Youth-onset Type 2 Diabetes Mellitus (T2DM) represents a major burden worldwide. In the last decades, the prevalence of T2DM became higher than that of Type 1 Diabetes Mellitus (T1DM), helped by the increasing rate of childhood obesity. The highest prevalence rates of youth-onset T2DM are recorded in China (520 cases/100,000) and in the United States (212 cases/100,000), and the numbers are still increasing. T2DM young people present a strong hereditary component, often unmasked by social and environmental risk factors. These patients are affected by multiple coexisting risk factors, including obesity, hyperglycemia, dyslipidemia, insulin resistance, hypertension, and inflammation. Juvenile T2DM nephropathy occurs earlier in life compared to T1DM-related nephropathy in children or T2DM-related nephropathy in adult. Diabetic kidney disease (DKD) is T2DM major long term microvascular complication. This review summarizes the main mechanisms involved in the pathogenesis of the DKD in young population and the recent evolution of treatment, in order to reduce the risk of DKD progression.

Effect of dietary sodium restriction on blood pressure in type 2 diabetes: A meta-analysis of randomized controlled trials

AIMS

Although current guidelines recommend reduction of salt intake in patients with diabetes, the benefits of reducing salt intake in people with type 2 diabetes mellitus (T2DM) lack clear evidence. Therefore, we performed a meta-analysis of available randomized controlled trials (RCTs) of sodium restriction and blood pressure (BP) in patients with T2DM.

DATA SYNTHESIS

We performed a systematic search of the online databases that evaluated the effect of dietary sodium restriction on BP in patients with T2DM. Sodium intake was expressed by 24 h urinary sodium excretion (UNaV). Q statistics and I² were used to explore between-study heterogeneity. A random-effects model was used in the presence of significant heterogeneity; otherwise, a fixed-effects model was applied. Eight RCTs with 10 trials (7 cross-over and 3 parallel designs) were included in the meta-analysis. Compared with ordinary sodium intake, dietary sodium restriction significantly decreased UNaV (weighted mean difference, WMD: -38.430 mmol/24 h; 95% CI: -41.665 mmol/24 h to -35.194 mmol/24 h). Sodium restriction significantly lowered systolic BP (WMD: -5.574 mm Hg; 95% CI: -8.314 to -2.834 mm Hg; I² = 0.0%) and diastolic BP (WMD: -1.675 mm Hg; 95% CI: -3.199 to -0.150 mm Hg; I² = 0.0%) with low heterogeneity among the studies. No publication bias was found from Begg's and Egger's tests.

CONCLUSIONS

Sodium restriction significantly reduces SBP and DBP in patients with T2DM.

Metabolic effects two years after renal denervation in insulin resistant hypertensive patients. The Re-Shape CV-risk study

BACKGROUND & AIMS

Denervation of renal sympathetic nerves (RDN) is an invasive endovascular procedure introduced as an antihypertensive treatment with a potential beneficial effect on insulin resistance (IR). We have previously demonstrated a reduction in blood pressure (BP) six months after RDN, but severe hepatic and peripheral IR, assessed by glucose tracer and two step hyperinsulinemic-euglycemic clamp (HEC), did not improve. The aim of the current study was to evaluate IR and adipokines profiles in relation to BP and arterial stiffness changes two years after RDN.

METHODS

In 20 non-diabetic patients with true treatment-resistant hypertension, ambulatory and office BP were measured after witnessed intake of medications prior to, six and 24 months after RDN. Arterial stiffness index (AASI) was calculated from ambulatory BP. Insulin sensitivity (IS) was assessed using an oral glucose tolerance test (OGTT), the Homeostasis Model Assessment (HOMA-IR), HOMA-Adiponectin Model Assessment (HOMA-AD), the Quantitative Insulin Sensitivity Check Index (QUICKI), the Triglyceride and Glucose Index (TyG) and the Leptin-to-Adiponectin Ratio (LAR). These surrogate indices of IS were compared with tracer/HEC measurements to identify which best correlated in this group of patients.

RESULTS

All measured metabolic variables and IS surrogate indices remained essentially unchanged two years after RDN apart from a significant increase in HOMA-AD. OGTT peak at 30 min correlated best with reduction in endogenous glucose release (EGR) during low insulin HEC (r = -0.6, p = 0.01), whereas HOMA-IR correlated best with whole-body glucose disposal (WGD) (r = -0.6, p = 0.01) and glucose infusion rate (r = -0.6, p = 0.01) during high insulin HEC. BP response was unrelated to IS prior to RDN. Nocturnal systolic BP and arterial stiffness before RDN correlated positively with a progression in hepatic IR at six-month follow-up.

CONCLUSION

IR, adiponectin and leptin did not improve two years after RDN. There was no correlation between baseline IS and BP response. Our study does not support the notion of a beneficial metabolic effect of RDN in patients with treatment resistant hypertension.

A Journey in Diabetes: From Clinical Physiology to Novel Therapeutics: The 2020 Banting Medal for Scientific Achievement Lecture

Insulin resistance and β-cell dysfunction are the core pathophysiological mechanisms of all hyperglycemic syndromes. Advances in in vivo investigative techniques have made it possible to quantify insulin resistance in multiple sites (skeletal and myocardial muscle, subcutaneous and visceral fat depots, liver, kidney, vascular tissues, brain and intestine), to clarify its consequences for tissue substrate selection, and to establish its relation to tissue perfusion. Physiological modeling of β-cell function has provided a uniform tool to measure β-cell glucose sensitivity and potentiation in response to a variety of secretory stimuli, thereby allowing us to establish feedbacks with insulin resistance, to delineate the biphasic time course of conversion to diabetes, to gauge incretin effects, and to identify primary insulin hypersecretion. As insulin resistance also characterizes several of the comorbidities of diabetes (e.g., obesity, hypertension, dyslipidemia), with shared genetic and acquired influences, the concept is put forward that diabetes is a systemic disease from the outset, actually from the prediabetic stage. In fact, early multifactorial therapy, particularly with newer antihyperglycemic agents, has shown that the burden of micro- and macrovascular complications can be favorably modified despite the rising pressure imposed by protracted obesity.

The association of erythropoietin-stimulating agents and increased risk for AV-fistula dysfunction in hemodialysis patients. A retrospective analysis

BACKGROUND

Patients in maintenance hemodialysis (HD) need a patent vascular access for optimal treatment. The recommended first choice is a native arteriovenous fistula (AVF). Complications of AVF are frequent and include thrombosis, stenosis and infections leading to worsening of dialysis efficacy. Some known risk factors are age, gender and the presence of diabetes mellitus. The aim was to investigate if further risk variables are associated with dysfunctional AVF.

METHODS

This retrospective observational study included 153 chronic HD patients (Cases) referred to a total of 473 radiological investigations due to clinically suspected complications of their native AVF. Another group of chronic HD patients (n = 52) who had a native AVF but were without history of previous complications for at least 2 years were controls. Statistical analyses included ANOVA, logistic regression, parametric and non-parametric methods such as Student's T-test and Mann-Whitney test.

RESULTS

Among Cases, at least one significant stenosis (> 50% of the lumen) was detected in 348 occasions. Subsequent PTA was performed in 248 (71%). Median erythropoiesis-stimulating agent (ESA) weekly doses were higher in Cases than in Controls (8000 vs 5000 IU, p < 0.001). Cases received higher doses of intravenous iron/week than the Controls before the investigation (median 50 mg vs 25 mg, p = 0.004) and low molecular weight heparin (LMWH, p = 0.028). Compared to Controls, Cases had a lower level of parathyroid hormone (median 25 vs 20 ρmol/L, p = 0.009). In patients with diabetes mellitus, HbA1c was higher among Cases than Controls (50 vs 38 mmol/mol, p < 0.001). Multiple regression analysis revealed significant associations between Cases and female gender, prescription of doxazocin, and doses of ESA and LMWH. There was no difference between the groups regarding hemoglobin, CRP or ferritin.

CONCLUSION

In conclusion, the present study indicated that the factors associated with AVF problems were high doses of ESA, iron administration, and tendency of thromboembolism (indicated by high LMWH doses); the use of doxazocin prescription, however, requires further investigation.

Dapagliflozin effects on haematocrit, red blood cell count and reticulocytes in insulin-treated patients with type 2 diabetes

Recent studies have shown that high-risk patients with type 2 diabetes mellitus (T2DM) treated with sodium glucose cotransporter 2 (SGLT2) inhibitors have improved cardiovascular (CV) outcomes. In an exploratory analysis of data from the EMPA-REG study, elevations in haematocrit were shown to be strongly associated with beneficial CV effects. As insulin treatment has been shown to be antinatriuretic, with an associated increase in extracellular fluid volume, it is important to confirm whether haematocrit increase is maintained with concomitant insulin therapy. Here, we investigate the effect of the SGLT2 inhibitor dapagliflozin on haematocrit, red blood cell (RBC) counts and reticulocyte levels in high-risk patients with T2DM receiving insulin. A 24-week, double-blinded, randomised, placebo-controlled trial (ClinicalTrials.gov: NCT00673231) was reported previously with extension periods of 24 and 56 weeks (total of 104 weeks). Patients receiving insulin were randomised 1:1:1:1 to placebo or dapagliflozin at 2.5, 5 or 10 mg. Haematocrit, RBC and reticulocyte measurements were conducted during this study, and a longitudinal repeated-measures analysis was performed here to examine change from baseline during treatment. Dapagliflozin treatment in combination with insulin resulted in a dose-dependent increase in haematocrit levels and RBCs over a 104 week period. There was a short-term increase in reticulocyte levels at the start of treatment, which dropped to below baseline after 8 weeks. SGLT2 inhibition with dapagliflozin leads to a sustained increase in haematocrit in patients receiving chronic insulin treatment.

Heart Failure in Diabetes Mellitus: An Updated Review

Diabetes mellitus (DM) and heart failure (HF) are comorbid conditions associated with significant morbidity and mortality worldwide. Despite the availability of novel and effective therapeutic options and intensive glycaemic control strategies, mortality and hospitalisation rates continue to remain high and the incidence of HF persists. In this review, we described the impact of currently available glucose-lowering therapies in DM with a focus on HF clinical outcomes. Non-conventional modes of management and alternative pathophysiological mechanisms with the potential for therapeutic targeting are also discussed.

Risk factors and fetal outcomes for preeclampsia in a Colombian cohort

In Latin America and the Caribbean, hypertensive pregnancy disorders are responsible for almost 26% of all maternal deaths [1] and, in Colombia, they account for 59% of all severe maternal morbidity (SMM) cases, and 59.7% of all SMM cases in adolescents [2]. One of the most important hypertensive pregnancy disorders is preeclampsia (PE). Lives can be saved, if PE is prevented, or detected early and properly managed. Prevention and detection depend on identifying the risk factors associated with PE, and, as these have been shown vary by population, they should be determined on a population-by-population basis. The following study utilized the nested case-control model to evaluate 45 potential PE risk factors of a cohort in Bogotá, Colombia, making it perhaps the most comprehensive study of its kind in Colombia. It found PE to have a statistically significant association with 7 of the 45 factors evaluated: 1) pre-gestational BMI >30 kg/m², 2) pregnancy weight gain >12 kg, 3) previous history preeclampsia/eclampsia, 4) previous history of IUGR-SGA (Intrauterine Growth Restriction-Small for Gestational Age), 5) maternal age <20 or ≥35 years (20–34 was not associated), and 6) family history of diabetes. Finally, prenatal consumption of folic acid was found to lower the risk of PE. We recommend that, in Colombia, factors 1–6 be used to identify at risk mothers during pregnancy check-ups; that mothers be encouraged to take folic acid during pregnancy; and, that Colombia's health system and public policy address the problem of pregestational obesity.

Hyponatraemia compounding pre-eclamptic toxaemia in a patient with type 1 diabetes

We report a case of profound, symptomatic hyponatraemia in association with pre-eclamptic toxaemia (PET) in a 38-year-old nulliparous woman with type 1 diabetes mellitus. This patient developed hypertension and proteinuria at 31+6 weeks' gestation and was admitted for management of pre-eclampsia. Severe headache, visual disturbance and nausea were associated with a hyponatraemia of 115 mmol/L followed by ketoacidosis. This was reversed through fluid restriction, supplementation with 1.8%-3.0% hypertonic saline and a volume-reduced variable-rate insulin infusion. Clinical stability was achieved and she was subsequently worked up for an induction of labour for worsening pre-eclampsia. Hyponatraemia in the context of PET has been previously reported as rare. However, it has complications that may significantly compound the sequelae of severe PET. We propose that specific and focused monitoring of serum sodium levels should become common practice in the management of women with this condition to allow for timely, measured correction of abnormalities.

Effect of insulin on natriuretic peptide gene expression in porcine heart

Gut hormones affect cardiac function and contractility. In this study, we examined whether insulin affects the cardiac atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) gene expression and release of proANP-derived peptides in pigs. Anaesthetized pigs were included in an experimental study comparing the effect of hyperinsulinemia in 15 pigs submitted to two different protocols versus 11 control pigs receiving saline infusion. Phosphorylation of Akt on Thr308 was determined by western blotting with a pAkt-Thr308 antibody. The mRNA contents of ANP and BNP were determined with real-time PCR; plasma and cardiac tissue proANP was measured with an immunoluminometric assay targeted against the mid-region of the propeptide and a processing-independent assay. Insulin stimulation increased phosphorylation of Akt Thr308 in both left atrium and left ventricle of porcine hearts (p < 0.005). No change was observed in ANP and BNP mRNA contents in the right or left atrium. BNP mRNA contents in the left ventricle, however, decreased 3-fold (p = 0.02) compared to control animals, whereas the BNP mRNA content in the right ventricle as well as ANP mRNA content in the right and left ventricle did not change following hyperinsulinemia. Moreover, the peptide contents did not change in the four cardiac chambers. Finally, proANP concentrations in plasma did not change during the insulin infusion compared to the control animals. These results suggest that insulin does not have direct effect on atrial natriuretic peptide expression but may have a role in the left ventricle.

Hyperinsulinemia rather than insulin resistance itself induces blood pressure elevation in high fat diet-fed rats

OBJECTIVE

To investigate if insulin resistance per se or the accompanying hyperinsulinemia induced hypertension and its underlying mechanisms.

METHODS

Sprague-Dawley rats were randomized into normal diet-fed group (ND group) and high-fat diet-fed group (HFD group). Then, the HFD group was further randomly divided into the control group (HFD_C group), the PIO group (treated with pioglitazone), the STZ_DM group (to induce diabetes with streptozotocin) and the DM+Ins group (streptozotocin injection followed by insulin treatment). Insulin sensitivity, plasma insulin, endothelin-1, norepinephrine, aldosterone, angiotensinⅡ and 24-h urinary sodium excretion (USE) levels of the groups were measured and analyzed. A multiple stepwise regression analysis method was applied to exam our hypothesis.

RESULTS

Compared to HFD_C group, the groups with lower plasma insulin, the PIO group and STZ_DM group, showed higher USE and lower blood pressure. The groups with higher plasma insulin (but same level of insulin resistance), the HFD_C group and DM+Ins group, showed lower USE and higher blood pressure. The 24-h urinary sodium excretion was the most important contributor to the significant changes of blood pressure with an R² of 25.2% in this animal experiment.

CONCLUSIONS

It is the compensatory hyperinsulinemia rather than insulin resistance per se that causes blood pressure elevation. The urinary sodium excretion is the key mediator among the multiple mechanisms. Therapies targeting hyperinsulinemia and restricting salt intake may favor a better control of hypertension associated with insulin resistance.

Importance of intensive blood pressure control in type 2 diabetes: Mechanisms, treatments and current guidelines

Observational and interventional studies have shown that intensified blood pressure (BP) reduction can benefit people with diabetes. Because of their special haemodynamic properties, renin-angiotensin-aldosterone system (RAAS) blockers are recommended. The results of the BP arm of the ADVANCE study strongly support the recently updated European Society of Cardiology/European Association of Diabetes recommendations for the treatment of BP in people with diabetes, which recommend a target systolic/diastolic BP of 130/80 mmHg with few exceptions, and a fixed combination of an RAAS blocker with a diuretic or a calcium channel blocker as first-line treatment.

Effect of Systemic Subnormal Deuterium Level on Metabolic Syndrome Related and other Blood Parameters in Humans: A Preliminary Study

The effects of deuterium depletion on the human organism have been, except for the antitumor action, seldom investigated by now and the available data are scarce. In oncological patients who also suffered from diabetes and were treated with deuterium-depleted water (DDW), an improvement of glucose metabolism was observed, and rat studies also proved the efficacy of DDW to reduce blood sugar level. In the present work, 30 volunteers with pre- or manifest diabetes were enrolled to a clinical study. The patients received 1.5 L of water with reduced deuterium content (104 ppm instead of 145 ppm, equivalent 12 mmol/L in human) daily for 90 days. The effects on fasting glucose and insulin level, on peripheral glucose disposal, and other metabolic parameters were investigated. Fasting insulin and glucose decreased, and insulin reaction on glucose load improved, in 15 subjects, while in the other 15 the changes were opposite. Peripheral glucose disposal was improved in 11 of the subjects. In the majority of the subjects, substantial increase of serum high-density lipoprotein (HDL) cholesterol and significant decrease of serum Na+ concentration were also seen-the latter possibly due to activation of a Na+/H+ antiporter by the decreased intracellular deuterium level. The results support the possible beneficial role of DDW in disorders of glucose metabolism but leave questions open, requiring further studies.

Refeeding syndrome : physiological background and practical management

Refeeding problems have been recognised since the the liberation of starved communities under siege. The main clinical problems may relate to hypophosphataemia, hypomagnesaemia and hypokalaemia with a risk of sudden death; thiamine deficiency with the risk of Wernike's encephalopathy/Korsakoff psychosis and sodium/water retention. The problems are greatest with oral/enteral feeding and especially with carbohydrate due to it increasing plasma insulin and thus glucose entry into cells. It is difficult to predict patients at risk of refeeding problems so there must be a high clinical suspicion on refeeding any malnourished patient (including any who have had no or very little nutrition for over 5 days). Generous vitamin and electrolyte supplementation may be given while monitoring closely and increasing the calorie intake reasonably rapidly from 10 to 20 kcal/kg/24 hours. Often patients in this category are not hungry, but over the course of a few days, the restoration of their appetite is an indication that the risks of refeeding have been managed and it is now safe to increase the feed aiming for repletion. If problems do occur, the feed should be slowed to the previous day's amount, reduced further or rarely stopped while fluid and electrolyte issues are corrected.

Management of Refeeding Syndrome in Medical Inpatients

Refeeding syndrome (RFS) is the metabolic response to the switch from starvation to a fed state in the initial phase of nutritional therapy in patients who are severely malnourished or metabolically stressed due to severe illness. It is characterized by increased serum glucose, electrolyte disturbances (particularly hypophosphatemia, hypokalemia, and hypomagnesemia), vitamin depletion (especially vitamin B1 thiamine), fluid imbalance, and salt retention, with resulting impaired organ function and cardiac arrhythmias. The awareness of the medical and nursing staff is often too low in clinical practice, leading to under-diagnosis of this complication, which often has an unspecific clinical presentation. This review provides important insights into the RFS, practical recommendations for the management of RFS in the medical inpatient population (excluding eating disorders) based on consensus opinion and on current evidence from clinical studies, including risk stratification, prevention, diagnosis, and management and monitoring of nutritional and fluid therapy.

Postprandial effects on electrolyte homeostasis in the kidney

Insulin is known to be an important regulator of a number of different channels and transporters in the kidney, but its role in the kidney to prevent Na⁺ and volume loss during the osmotic load after a meal has only recently been validated. With increasing numbers of people suffering from diabetes and hypertension, furthering our understanding of insulin signaling and renal Na⁺ handling in both normal and diseased states is essential for improving patient treatments and outcomes. The present review is focused on postprandial effects on Na⁺ reabsorption in the kidney and the role of the epithelial Na⁺ channels as an important channel contributing to insulin-mediated Na⁺ reclamation.

Continuous Subcutaneous Insulin Infusion Initiation Is Associated With Blood Pressure Reduction in Adults With Type 1 Diabetes

BACKGROUND

In type 1 diabetes (T1D) continuous subcutaneous insulin infusion (CSII) use has been associated with lower risks for mortality and diabetes-related complications when compared to multiple daily injections. There are limited data on the effect of CSII on blood pressure (BP). We aimed to evaluate the relationship between CSII initiation and BP changes.

METHODS

We performed a retrospective, single-center, observational study including all adults with T1D who initiated CSII between 2001 and 2014. Mean systolic BP levels were calculated from values obtained up to 15 months before and up 15 months after CSII initiation.

RESULTS

We studied 436 adults (46% male; mean [95% CI] age: 45 [36, 54] years, duration of diabetes: 20.3 [19.1, 21.5] years). CSII was associated with the following changes (post minus pre CSII levels) in mean (95% CI) SBP and DBP levels, respectively: whole cohort (N = 436): -2 (-1, -3), P < .001 and -2 (-1, -2), P < .001; those taking stable antihypertensive medication (n = 118): -4 (-6, -2), P < .001 and -2 (-3, -1), P < .001; antihypertensive treatment-naïve patients (n = 279): -1 (-2, 0), P = .147 and -1 (-2, 0), P = .002. In multivariate regression analysis including age, sex, diabetes duration, pre-CSII BP, HbA1c and weight changes, only pre-CSII BP showed an independent association with BP drop in all patients' groups. Once adjusted for pre-CSII BP there was no significant difference between those on antihypertensive drugs and antihypertensive treatment-naïve individuals.

CONCLUSIONS

We showed BP reduction in association with CSII therapy particularly in those on antihypertensive medication. These original findings may partly explain the cardiovascular and mortality benefits associated with CSII therapy.

Effects of differing levels of carbohydrate restriction on mood achievement of nutritional ketosis, and symptoms of carbohydrate withdrawal in healthy adults: A randomized clinical trial

OBJECTIVES

To our knowledge, minimal research exists on the effects of diets differing in carbohydrate restriction on symptoms of carbohydrate withdrawal and mood, and the achievement of nutritional ketosis (NK). The aim of this study was to compare ketonaemia, symptoms of carbohydrate withdrawal, and mood. We hypothesized that a moderate carbohydrate restriction would result in fewer symptoms and a reduced effect on mood.

METHODS

Seventy-seven healthy participants (25 men and 52 women; mean age: 39 y, range: 25-49; mean body mass index 27 kg/m², range: 20-39) were randomized to receive either a very-low-carbohydrate ketogenic diet (VLCKD), low-carbohydrate diet (LCD), or moderately low-carbohydrate diet (MCD), containing 5%, 15%, and 25% total energy (TE) from carbohydrate, respectively, for 3 wk. Fasting blood ketone measures were recorded daily upon waking along with a data from symptom questionnaire and a 5-point mood-state scale. Using analysis of variance and a 5% two-sided α level to determine statistical significance, between-group outcomes were analyzed. Additional association and analyses were conducted by multiple linear regression.

RESULTS

In 75 of 77 initial participants included for analysis, mean serum levels of β-hydroxybutyrate (βOHB) were increased by 0.27 ± 0.32, 0.41 ± 0.38, and 0.62 ± 0.49 mmol/L for MCD, LCD, and VLCKD, respectively (P = 0.013). The achievement of NK was consistent for both VLCKD and LCD groups and sporadic for the MCD group. Only the VLCKD group exhibited 95% confidence interval levels that were consistently ≥0.5 mmol/L. The overall mean change in sum of symptoms scores (SOSS) from baseline was 0.81 ± 2.84 (P < 0.001). Changes in SOSS were highest in the VLCKD group (1.49 ± 2.47), followed by LCD (0.65 ± 2.70) and MCD (0.18 ± 3.3; P = 0.264). Small, statistically significant increases were seen for headache severity, constipation, diarrhea, halitosis, muscle cramps and muscle weakness, and light-headedness, whereas intestinal bloating and craving for sugar and starch improved from baseline. Only halitosis (P = 0.039) and muscle weakness (P = 0.005) differed significantly between the groups. Mood improved significantly from baseline overall, but there was no significant difference between groups (P = 0.181) CONCLUSIONS: Diets containing 5% TE from carbohydrates are ketogenic, but diets containing between 15% and 25% TE from carbohydrates can also result in mean βOHB ≥0.5 mmol/L. There was no meaningful difference in symptoms of carbohydrate withdrawal between diets that contain 5% to 25% TE from carbohydrate, and mood was improved overall, with no significant difference between interventions. Our conclusion, therefore, is that reduced carbohydrate diets should be prescribed by need rather than the desire to mitigate symptoms of carbohydrate withdrawal.