Changes in serum potassium mediate thiazide-induced diabetes

Clinical profile of patients with diabetic ketoacidosis and hyperglycemic hyperosmolar syndrome in Japan: a multicenter retrospective cohort study

INTRODUCTION

Diabetic ketoacidosis (DKA) and hyperglycemic hyperosmolar syndrome (HHS) are life-threatening complications of diabetes mellitus. Their clinical profiles have not been fully investigated.

METHODS

A multicenter retrospective cohort study was conducted in 21 acute care hospitals in Japan. Patients included were adults aged 18 or older who had been hospitalized from January 1, 2012, to December 31, 2016 due to DKA or HHS. The data were extracted from patient medical records. A four-group comparison (mild DKA, moderate DKA, severe DKA, and HHS) was performed to evaluate outcomes.

RESULTS

A total of 771 patients including 545 patients with DKA and 226 patients with HHS were identified during the study period. The major precipitating factors of disease episodes were poor medication compliance, infectious diseases, and excessive drinking of sugar-sweetened beverages. The median hospital stay was 16 days [IQR 10-26 days]. The intensive care unit (ICU) admission rate was 44.4% (mean) and the rate at each hospital ranged from 0 to 100%. The in-hospital mortality rate was 2.8% in patients with DKA and 7.1% in the HHS group. No significant difference in mortality was seen among the three DKA groups.

CONCLUSIONS

The mortality rate of patients with DKA in Japan is similar to other studies, while that of HHS was lower. The ICU admission rate varied among institutions. There was no significant association between the severity of DKA and mortality in the study population.

TRIAL REGISTRATION

This study is registered in the UMIN clinical Trial Registration System (UMIN000025393, Registered 23th December 2016).

Gitelman syndrome combined with diabetes mellitus: A case report and literature review

RATIONALE

Gitelman syndrome (GS) is an uncommon autosomal recessive tubulopathy resulting from a functional deletion mutation in the SLC12A3 gene. Its onset is typically insidious and challenging to discern, and it is characterized by hypokalemia, metabolic alkalosis, and reduced urinary calcium excretion. There is limited literature on the diagnosis and management of GS in individuals with concomitant diabetes.

PATIENT CONCERNS

A 36-year-old male patient with a longstanding history of diabetes exhibited suboptimal glycemic control. Additionally, he presented with concurrent findings of hypokalemia, hypomagnesemia, hypocalciuria, and metabolic alkalosis.

DIAGNOSIS

Building upon the patient's clinical manifestations and extensive laboratory evaluations, we conducted thorough genetic testing, leading to the identification of a compound heterozygous mutation within the SLC12A3 gene. This definitive finding confirmed the diagnosis of GS.

INTERVENTIONS

We have formulated a detailed medication regimen for patients, encompassing personalized selection of hypoglycemic medications and targeted electrolyte supplementation.

OUTCOMES

Following 1 week of comprehensive therapeutic intervention, the patient's serum potassium level effectively normalized to 3.79 mmol/L, blood glucose parameters stabilized, and there was significant alleviation of clinical symptoms.

LESSONS

GS has a hidden onset and requires early diagnosis and intervention based on patient related symptoms and laboratory indicators in clinical practice, and personalized medication plans need to be provided according to the specific situation of the patient.

Hydrochlorothiazide-induced glucose metabolism disorder is mediated by the gut microbiota via LPS-TLR4-related macrophage polarization

Hydrochlorothiazide (HCTZ) is reported to impair glucose tolerance and may induce new onset of diabetes, but the pharmacomicrobiomics of the adverse effect for HCTZ remains unknown. Mice-fed HCTZ exhibited insulin resistance and impaired glucose tolerance. By using FMT and antibiotic cocktail models, we found that HCTZ-induced metabolic disorder was mediated by commensal microbiota. HCTZ consumption disturbed the structure of the intestinal microbiota, causing abnormal elevation of Gram-negative Enterobacteriaceae and lipopolysaccharide (LPS) then leading to intestinal barrier dysfunction. Additionally, HCTZ activated TLR4 signaling and induced macrophage polarization and inflammation in the liver. Furthermore, HCTZ-induced macrophage polarization and metabolic disorder were abrogated by blocking TLR4 signaling. HCTZ consumption caused a significant increase in Gram-negative Enterobacteriaceae, which elevated the levels of LPS, thereby activating LPS/TLR4 pathway, promoting inflammation and macrophage polarization, and resulting in metabolic disorders. These findings revealed that the gut microbiome is the key medium underlying HCTZ-induced metabolic disorder.

Case report: Gitelman syndrome with diabetes: Confirmed by both hydrochlorothiazide test and genetic testing

RATIONALE

Gitelman syndrome (GS) is an autosomal recessive tubulopathy caused by mutations of the SLC12A3 gene. It is characterized by hypokalemic metabolic alkalosis, hypomagnesemia and hypocalciuria. Hypokalemia, hypomagnesemia, and increased renin-angiotensin-aldosterone system (RAAS) activity can cause glucose metabolism dysfunction. The diagnosis of GS includes clinical diagnosis, genetic diagnosis and functional diagnosis. The gene diagnosis is the golden criterion while as functional diagnosis is of great value in differential diagnosis. The hydrochlorothiazide (HCT) test is helpful to distinguish GS from batter syndrome, but few cases have been reported to have HCT testing.

PATIENT CONCERNS

A 51-year-old Chinese woman presented to emergency department because of intermittent fatigue for more than 10 years.

DIAGNOSES

Laboratory test results showed hypokalemia, hypomagnesemia, hypocalciuria and metabolic alkalosis. The HCT test showed no response. Using next-generation and Sanger sequencing, we identified 2 heterozygous missense variants (c.533C > T:p.S178L and c.2582G > A:p.R861H) in the SLC12A3 gene. In addition, the patient was diagnosed with type 2 diabetes mellitus 7 years ago. Based on these findings, the patient was diagnosed with GS with type 2 diabetic mellitus (T2DM).

INTERVENTIONS

She was given potassium and magnesium supplements, and dapagliflozin was used to control her blood glucose.

OUTCOMES

After treatments, her fatigue symptoms were reduced, blood potassium and magnesium levels were increased, and blood glucose levels were well controlled.

LESSONS

When GS is considered in patients with unexplained hypokalemia, the HCT test can be used for differential diagnosis, and genetic testing can be continued to confirm the diagnosis when conditions are available. GS patients often have abnormal glucose metabolism, which is mainly caused by hypokalemia, hypomagnesemia, and secondary activation of RAAS. When a patient is diagnosed with GS and type 2 diabetes, sodium-glucose cotransporter 2 inhibitors (SGLT2i) can be used to control the blood glucose level and assist in raising blood magnesium.

Thiazide and thiazide-like diuretics: how to make the right choice?

Most patients with arterial hypertension (AH) require a combination treatment to achieve the goal blood pressure. According to Russian and international clinical guidelines on the treatment of AH patients, various antihypertensive drugs may be combined; however, not all combinations have similar profiles of safety and clinical efficacy. In this respect, special attention is given to combinations of renin-angiotensin-aldosterone system inhibitors and thiazide (hydrochlorothiazide) or thiazide-like (chlortalidone, indapamide) diuretics. Diuretics also differ in their mechanisms of action, presence of pleiotropic effects and organ-protective properties, effects on the prognosis, and in the evidence base. This review discusses the place of thiazide and thiazide-like diuretics in the treatment of patients with AH and provides an evaluation of major differences in pharmacological and clinical effects of drugs of the diuretic class.

Cardiovascular disease and risk of incident diabetes mellitus: Findings from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL)

BACKGROUND

Studies have reported an association between prevalent cardiovascular disease (CVD) and risk of diabetes mellitus (DM). However, factors that may explain the association remain unclear. We examined the association of prevalent CVD with incident DM and assessed whether weight gain and medication use may explain the association.

METHODS

Data from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) Visit 1 (2008-2011) and Visit 2 (2014-2017) were used to compare incidence of DM among individuals with and without self-reported CVD at Visit 1. A total of 1899 individuals with self-reported CVD were matched to controls free of self-reported CVD at Visit 1 using 1:1 propensity score matching. Covariates included in the propensity model were sociodemographic characteristics, lifestyle factors, comorbid conditions, and study site. The effect of self-reported CVD on incident DM was examined using a generalized estimating equation. The mediating effects of weight gain and use of cardiovascular medications were evaluated.

RESULTS

Covariate distributions were similar among individuals with and without self-reported CVD. The incidence of DM among persons with self-reported CVD was 15.3% vs 12.7% among those without self-reported CVD. Compared to individuals without self-reported CVD, individuals with self-reported CVD had a 24% increased risk for incident DM (odds ratio = 1.24, 95% confidence interval = 1.01, 1.51). The association between self-reported CVD and DM was mediated by the use of beta-blockers (proportion explained = 25.4%), statins (proportion explained = 18%), and diuretics (proportion explained = 8%). We found that weight gain did not explain the observed association.

CONCLUSIONS

Prevalent cardiovascular disease was associated with a significant increased risk of incident diabetes. The observed association was partially explained by some medications used to manage CVD.

Potassium supplementation blunts the effects of high salt intake on serum retinol-binding protein 4 levels in healthy individuals

Aims/Introduction

Excessive dietary salt or low potassium intakes are strongly correlated with insulin resistance (IR) and type 2 diabetes mellitus. In epidemiological and experimental studies, increased serum retinol‐binding protein 4 (RBP4) contributes to the pathogenesis of type 2 diabetes mellitus. Herein, we hypothesized that RBP4 might be an adipocyte‐derived “signal” that plays the crucial role in salt‐related insulin resistance or type 2 diabetes mellitus. This study aimed to assess whether salt consumption and potassium supplementation influence serum RBP4 levels in healthy individuals.

Materials and Methods

A total of 42 participants (aged 25–50 years) in a rural area of Northern China were successively provided normal (3 days at baseline), low‐salt (7 days; 3 g/day NaCl) and high‐salt (7 days; 18 g/day) diets, and a high‐salt diet with potassium additive (7 days; 18 g/day NaCl and 4.5 g/day KCl). Urinary sodium and potassium were measured to ensure compliance to dietary intervention. Then, RBP4 levels were evaluated by enzyme‐linked immunosorbent assay.

Results

High salt intake significantly raised serum RBP4 levels in healthy participants (17.5 ± 0.68 vs 28.6 ± 1.02 µg/mL). This phenomenon was abrogated by potassium supplementation (28.6 ± 1.02 vs 17.6 ± 0.88 µg/mL). In addition, RBP4 levels presented positive (r = 0.528, P < 0.01) and negative (r = −0.506, P < 0.01) associations with 24‐h urinary sodium‐ and potassium excretion levels.

Conclusions

RBP4 synthesis is motivated by high salt intake and revoked by potassium supplementation. Our pioneer work has contributed to the present understanding of salt‐induced insulin resistance or type 2 diabetes mellitus.

Type 2 diabetes mellitus caused by Gitelman syndrome-related hypokalemia: A case report

INTRODUCTION

Gitelman syndrome (GS) is an autosomal-recessive disease caused by SLC12A3 gene mutations. It is characterized by hypokalemic metabolic alkalosis in combination with hypomagnesemia and hypocalciuria. Recently, patients with GS are found at an increased risk for developing type 2 diabetes mellitus (T2DM). However, diagnosis of hyperglycemia in GS patients has not been thoroughly investigated, and family studies on SLC12A3 mutations and glucose metabolism are rare. Whether treatment including potassium and magnesium supplements, and spironolactone can ameliorate impaired glucose tolerance in GS patients, also needs to be investigated.

PATIENT CONCERNS

We examined a 55-year-old Chinese male with intermittent fatigue and persistent hypokalemia for 17 years.

DIAGNOSES

Based on the results of the clinical data, including electrolytes, oral glucose tolerance test (OGTT), and genetic analysis of the SLC12A3 gene, GS and T2DM were newly diagnosed in the patient. Two mutations of the SLC12A3 gene were found in the patient, one was a missense mutation p.N359K in exon 8, and the other was a novel insert mutation p.I262delinsIIGVVSV in exon 6. SLC12A3 genetic analysis and OGTT of 9 other family members within 3 generations were also performed. Older brother, youngest sister, and son of the patient carried the p.N359K mutation in exon 8. The older brother and the youngest sister were diagnosed with T2DM and impaired glucose tolerance by OGTT, respectively.

INTERVENTIONS

The patient was prescribed potassium and magnesium (potassium magnesium aspartate, potassium chloride) oral supplements and spironolactone. The patient was also suggested to maintain a high potassium diet. Acarbose was used to maintain the blood glucose levels.

OUTCOMES

The electrolyte imbalance including hypokalemia and hypomagnesemia, and hyperglycemia were improved with a remission of the clinical manifestations.

CONCLUSION

GS is one of the causes for manifestation of hypokalemia. SLC12A3 genetic analysis plays an important role in diagnosis of GS. Chinese male GS patients characterized with heterozygous SLC12A3 mutation should be careful toward occurrence of T2DM. Moreover, the patients with only 1 SLC12A3 mutant allele should pay regular attention to blood potassium and glucose levels. GS treatment with potassium and magnesium supplements, and spironolactone can improve impaired glucose metabolism.

Thiazide Diuretic-Induced Change in Fasting Plasma Glucose: a Meta-analysis of Randomized Clinical Trials

BACKGROUND

Prior meta-analyses measuring thiazide-induced glycemic change have demonstrated an increased risk of incident diabetes; however, this measure's definition has changed over time.

AIM

To determine the magnitude of change in fasting plasma glucose (FPG) for thiazide diuretics.

DATA SOURCES

A research librarian designed and conducted searches in Medline®, EMBASE, and EBM Reviews-Cochrane Central Register of Controlled Trials (inception through July 2018) and International Pharmaceutical Abstracts (inception to December 2014).

STUDY SELECTION

Randomized, controlled trials comparing a thiazide or thiazide-like diuretic to any comparator reporting FPG were identified. Trials enrolling < 50 participants, those with a follow-up period of < 4 weeks, and conference abstracts were excluded.

DATA EXTRACTION

Independent duplicate screening of citations and full-text articles, data extraction, and assessment of risk of bias was conducted.

DATA SYNTHESIS

Ninety-five studies were included (N = 76,608 participants), with thiazides compared with placebo, beta-blockers, calcium channel blockers, renin-angiotensin-aldosterone-system inhibitors, potassium-sparing diuretic, and others alone or in combination. Thiazide diuretics marginally increased FPG (weighted mean difference 0.20 mmol/L (95% CI 0.15-0.25); I² = 84%) (1 mmol/L = 18 mg/dL). Results did not change substantially when considering dose or duration, comparing thiazides with placebo or an active comparator, or using thiazides as monotherapy or combination therapy, even when combined with a potassium-correcting agent.

CONCLUSION

Thiazide diuretics have a small and clinically unimportant impact on FPG.

Diabetes Mellitus and Osteoporosis Correlation: Challenges and Hopes

Diabetes and osteoporosis are two common diseases with different complications. Despite different therapeutic strategies, managing these diseases and reducing their burden have not been satisfactory, especially when they appear one after the other. In this review, we aimed to clarify the similarity, common etiology and possible common adjunctive therapies of these two major diseases and designate the known molecular pattern observed in them. Based on different experimental findings, we want to illuminate that interestingly similar pathways lead to diabetes and osteoporosis. Meanwhile, there are a few drugs involved in the treatment of both diseases, which most of the time act in the same line but sometimes with opposing results. Considering the correlation between diabetes and osteoporosis, more efficient management of both diseases, in conditions of concomitant incidence or cause and effect condition, is required.

Characteristics and Follow-Up of 13 pedigrees with Gitelman syndrome

CONTEXT

Gitelman syndrome (GS) is clinically heterogeneous. The genotype and phenotype correlation has not been well established. Though the long-term prognosis is considered to be favorable, hypokalemia is difficult to cure.

OBJECTIVE

To analyze the clinical and genetic characteristics and treatment of all members of 13 GS pedigrees.

METHODS

Thirteen pedigrees (86 members, 17 GS patients) were enrolled. Symptoms and management, laboratory findings, and genotype-phenotype associations among all the members were analyzed.

RESULTS

The average ages at onset and diagnosis were 27.6 ± 10.2 years and 37.9 ± 11.6 years, respectively. Males were an average of 10 years younger and exhibited more profound hypokalemia than females. Eighteen mutations were detected. Two novel mutations (p.W939X, p.G212S) were predicted to be pathogenic by bioinformatic analysis. GS patients exhibited the lowest blood pressure, serum K⁺, Mg²⁺, and 24-h urinary Ca²⁺ levels. Although blood pressure, serum K⁺ and Mg²⁺ levels were normal in heterozygous carriers, 24-h urinary Na⁺ excretion was significantly increased. During follow-up, only 41.2% of patients reached a normal serum K⁺ level. Over 80% of patients achieved a normal Mg²⁺ level. Patients were taking 2-3 medications at higher doses than usual prescription to stabilize their K⁺ levels. Six patients were taking spironolactone simultaneously, but no significant elevation in the serum K⁺ level was observed.

CONCLUSION

The phenotypic variability of GS and therapeutic strategies deserve further research to improve GS diagnosis and prognosis. Even heterozygous carriers exhibited increased 24-h Na⁺ urine excretion, which may make them more susceptible to diuretic-induced hypokalemia.

Drug-induced diabetes type 2: In silico study involving class B GPCRs

A disturbance of glucose homeostasis leading to type 2 diabetes mellitus (T2DM) is one of the severe side effects that may occur during a prolonged use of many drugs currently available on the market. In this manuscript we describe the most common cases of drug-induced T2DM, discuss available pharmacotherapies and propose new ones. Among various pharmacotherapies of T2DM, incretin therapies have recently focused attention due to the newly determined crystal structure of incretin hormone receptor GLP1R. Incretin hormone receptors: GLP1R and GIPR together with the glucagon receptor GCGR regulate food intake and insulin and glucose secretion. Our study showed that incretin hormone receptors, named also gut hormone receptors as they are expressed in the gastrointestinal tract, could potentially act as unintended targets (off-targets) for orally administrated drugs. Such off-target interactions, depending on their effect on the receptor (stimulation or inhibition), could be beneficial, like in the case of incretin mimetics, or unwanted if they cause, e.g., decreased insulin secretion. In this in silico study we examined which well-known pharmaceuticals could potentially interact with gut hormone receptors in the off-target way. We observed that drugs with the strongest binding affinity for gut hormone receptors were also reported in the medical information resources as the least disturbing the glucose homeostasis among all drugs in their class. We suggested that those strongly binding molecules could potentially stimulate GIPR and GLP1R and/or inhibit GCGR which could lead to increased insulin secretion and decreased hepatic glucose production. Such positive effect on the glucose homeostasis could compensate for other, adverse effects of pharmacotherapy which lead to drug-induced T2DM. In addition, we also described several top hits as potential substitutes of peptidic incretin mimetics which were discovered in the drug repositioning screen using gut hormone receptors structures against the ZINC15 compounds subset.

KCNJ11 variants and their effect on the association between serum potassium and diabetes risk in the Atherosclerosis Risk in Communities (ARIC) Study and Jackson Heart Study (JHS) cohorts

BACKGROUND

In the Atherosclerosis Risk in Communities (ARIC) Study and Jackson Heart Study (JHS) cohorts, serum potassium (K) is an independent predictor of diabetes risk, particularly among African-American participants. Experimental studies show that serum K levels affects insulin secretion. The KCNJ11 gene encodes for a K channel that regulates insulin secretion and whose function is affected by serum K levels. Variants in KCNJ11 are associated with increased diabetes risk. We hypothesized that there could be a gene-by-environment interaction between KCNJ11 variation and serum K on diabetes risk.

METHODS

Evaluating a combined cohort of ARIC and JHS participants, we sought to determine if KCNJ11 variants are risk factors for diabetes; and if KCNJ11 variants modify the association between serum K and diabetes risk. Among participants without diabetes at baseline, we performed multivariable logistic regression to determine the effect of serum K, KCNJ11 variants, and their interactions on the odds of incident diabetes mellitus over 8-9 years in the entire cohort and by race.

RESULTS

Of 11,812 participants, 3220 (27%) participants developed diabetes. 48% and 47% had 1 or 2 diabetes risk alleles of rs5215 and rs5219, respectively. Caucasians had higher proportions of these risk alleles compared to African Americans (60% vs 17% for rs5215 and 60% vs 13% for rs5219, p<0.01). Serum K was a significant independent predictor of incident diabetes. Neither rs5215 nor rs5219 was associated with incident diabetes. In multivariable models, we found no statistically significant interactions between race and either rs5215 or rs5219 (P-values 0.493 and 0.496, respectively); nor between serum K and either rs5215 or rs5219 on odds of incident diabetes (P-values 0.534 and 0.687, respectively).

CONCLUSION

In this cohort, rs5215 and rs5219 of KCNJ11 were not significant predictors of incident diabetes nor effect modifiers of the association between serum K and incident diabetes.

Blood pressure signature genes and blood pressure response to thiazide diuretics: results from the PEAR and PEAR-2 studies

Background

Recently, 34 genes had been associated with differential expression relative to blood pressure (BP)/ hypertension (HTN). We hypothesize that some of the genes associated with BP/HTN are also associated with BP response to antihypertensive treatment with thiazide diuretics.

Methods

We assessed these 34 genes for association with differential expression to BP response to thiazide diuretics with RNA sequencing in whole blood samples from 150 hypertensive participants from the Pharmacogenomic Evaluation of Antihypertensive Responses (PEAR) and PEAR-2 studies. PEAR white and PEAR-2 white and black participants (n = 50 for each group) were selected based on the upper and lower quartile of BP response to hydrochlorothiazide (HCTZ) and to chlorthalidone.

Results

FOS, DUSP1 and PPP1R15A were differentially expressed across all cohorts (meta-analysis p-value < 2.0 × 10^− 6), and responders to HCTZ or chlorthalidone presented up-regulated transcripts. Rs11065987 in chromosome 12, a trans-eQTL for expression of FOS, PPP1R15A and other genes, is also associated with BP response to HCTZ in PEAR whites (SBP: β = − 2.1; p = 1.7 × 10^− 3; DBP: β = − 1.4; p = 2.9 × 10^− 3).

Conclusions

These findings suggest FOS, DUSP1 and PPP1R15A as potential molecular determinants of antihypertensive response to thiazide diuretics.

Trial registration

NCT00246519, NCT01203852www.clinicaltrials.gov

Electronic supplementary material

The online version of this article (10.1186/s12920-018-0370-x) contains supplementary material, which is available to authorized users.

Incidence of hyperglycemia and diabetes and association with electrolyte abnormalities in pediatric solid organ transplant recipients

Background

Posttransplant hyperglycemia is an important predictor of new-onset diabetes after transplantation, and both are associated with significant morbidity and mortality. Precise estimates of posttransplant hyperglycemia and diabetes in children are unknown. Low magnesium and potassium levels may also lead to diabetes after transplantation, with limited evidence in children.

Methods

We conducted a cohort study of 451 pediatric solid organ transplant recipients to determine the incidence of hyperglycemia and diabetes, and the association of cations with both endpoints. Hyperglycemia was defined as random blood glucose levels ≥11.1 mmol/L on two occasions after 14 days of transplant not requiring further treatment. Diabetes was defined using the American Diabetes Association Criteria. For magnesium and potassium, time-fixed, time-varying and rolling average Cox proportional hazards models were fitted to evaluate the association with hyperglycemia and diabetes.

Results

Among 451 children, 67 (14.8%) developed hyperglycemia and 27 (6%) progressed to diabetes at a median of 52 days (interquartile range 22-422) from transplant. Multi-organ recipients had a 9-fold [hazard ratio (HR) 8.9; 95% confidence interval (CI) 3.2-25.2] and lung recipients had a 4.5-fold (HR 4.5; 95% CI 1.8-11.1) higher risk for hyperglycemia and diabetes, respectively, compared with kidney transplant recipients. Both magnesium and potassium had modest or no association with the development of hyperglycemia and diabetes.

Conclusions

Hyperglycemia and diabetes occur in 15 and 6% children, respectively, and develop early posttransplant with lung or multi-organ transplant recipients at the highest risk. Hypomagnesemia and hypokalemia do not confer significantly greater risk for hyperglycemia or diabetes in children.

Impact of long-term potassium supplementation on thiazide diuretic-induced abnormalities of glucose and uric acid metabolisms

Treatment of hypertension with thiazide diuretics may trigger hypokalemia, hyperglycemia, and hyperuricemia. Some studies suggest simultaneous potassium supplementation in hypertensive patients using thiazide diuretics. However, few clinical studies have reported the impact of long-term potassium supplementation on thiazide diuretic-induced abnormalities in blood glucose and uric acid (UA) metabolisms. One hundred hypertensive patients meeting the inclusion criteria were equally randomized to two groups: IND group receiving indapamide (1.25-2.5 mg daily) alone, and IND/KCI group receiving IND (1.25-2.5 mg daily) plus potassium chloride (40 mmol daily), both for 24 weeks. At the end of 24-week follow-up, serum K⁺ level in IND group decreased from 4.27 ± 0.28 to 3.98 ± 0.46 mmol/L (P < 0.001), and fasting plasma glucose (FPG) and UA increased from 5.11 ± 0.52 to 5.31 ± 0.57 mmol/L (P < 0.05), and from 0.404 ± 0.078 to 0.433 ± 0.072 mmol/L (P < 0.05), respectively. Serum K⁺ level in IND/KCl group decreased from 4.27 ± 0.36 to 3.89 ± 0.28 mmol/L (P < 0.001), and FPB and UA increased from 5.10 ± 0.41 to 5.35 ± 0.55 mmol/L (P < 0.01), and from 0.391 ± 0.073 to 0.457 ± 0.128 mmol/L (P < 0.001), respectively. The difference value between the serum K⁺ level and FPG before and after treatment was not statistically significant between the two groups. However, the difference value in UA in IND/KCl group was significantly higher than that in IND group (0.066 (95% confidence interval (CI): 0.041-0.090)  mmol/L vs. 0.029 (95% CI: 0.006-0.058) mmol/L, P < 0.05). The results showed that long-term routine potassium supplementation could not prevent or attenuate thiazide diuretic-induced abnormalities of glucose metabolism in hypertensive patients; rather, it may aggravate the UA metabolic abnormality.

Effects of potassium supplements on glucose metabolism in African Americans with prediabetes: a pilot trial

Background: Low potassium has been identified both as a risk factor for type 2 diabetes and as a mediator of the racial disparity in diabetes risk. Low potassium could be a potentially modifiable risk factor, particularly for African Americans.Objective: We sought to determine the effects of potassium chloride (KCl) supplements, at a commonly prescribed dose, on measures of potassium and glucose metabolism.Design: Among African-American adults with prediabetes, we conducted a double-blinded pilot randomized controlled trial that compared the effects of 40 mEq K/d as KCl supplements with a matching placebo, taken for 3 mo, on measures of potassium and glucose metabolism, with measures collected from frequently sampled oral-glucose-tolerance tests (OGTTs).Results: Twenty-seven of 29 recruited participants completed the trial. Participants had high adherence to the study medication (92% by pill count). Participants in both groups gained weight, with an overall mean ± SD weight gain of 1.24 ± 2.03 kg. In comparison with participants who received placebo, urine potassium but not serum potassium increased significantly among participants randomly assigned to receive KCl (P = 0.005 and 0.258, respectively). At the end of the study, participants taking KCl had stable or improved fasting glucose, with a mean ± SD change in fasting glucose of -1.1 ± 8.4 mg/dL compared with an increase of 6.1 ± 7.6 mg/dL in those who received placebo (P = 0.03 for comparison between arms). There were no significant differences in glucose or insulin measures during the OGTT between the 2 groups, but there was a trend for improved insulin sensitivity in potassium-treated participants.Conclusions: In this pilot trial, KCl at a dose of 40 mEq/d did not increase serum potassium significantly. However, despite weight gain, KCl prevented worsening of fasting glucose. Further studies in larger sample sizes, as well as with interventions to increase serum potassium more than was achieved with our intervention, are indicated to definitively test this potentially safe and inexpensive approach to reducing diabetes risk. This trial was registered at clinicaltrials.gov as NCT02236598.

Whole Transcriptome Sequencing Analyses Reveal Molecular Markers of Blood Pressure Response to Thiazide Diuretics

Thiazide diuretics (TD) are commonly prescribed anti-hypertensives worldwide. However, <40% of patients treated with thiazide monotherapy achieve BP control. This study uses whole transcriptome sequencing to identify novel molecular markers associated with BP response to TD. We assessed global RNA expression levels in whole blood samples from 150 participants, representing patients in the upper and lower quartile of BP response to TD from the Pharmacogenomic Evaluation of Antihypertensive Responses (PEAR) (50 whites) and from PEAR-2 (50 whites and 50 blacks). In each study cohort, we performed poly-A RNA-sequencing in baseline samples from 25 responders and 25 non-responders to hydrochlorothiazide (HCTZ) or chlorthalidone. At FDR adjusted p-value < 0.05, 29 genes were differentially expressed in relation to HCTZ or chlorthalidone BP response in whites. For each differentially expressed gene, replication was attempted in the alternate white group and PEAR-2 blacks. CEBPD (meta-analysis p = 1.8 × 10⁻¹¹) and TSC22D3 (p = 1.9 × 10⁻⁹) were differentially expressed in all 3 cohorts, and explain, in aggregate, 21.9% of response variability to TD. This is the first report of the use of transcriptome-wide sequencing data to identify molecular markers of antihypertensive drug response. These findings support CEBPD and TSC22D3 as potential biomarkers of BP response to TD.

Potassium measurements and risk of type 2 diabetes: a dose-response meta-analysis of prospective cohort studies

Objective

To clarify the relationship between serum, dietary, and urinary potassium and the risk of type 2 diabetes mellitus (T2DM).

Materials and Methods

We searched PubMed and EMBASE through January 6, 2017 for studies reporting risk estimates on the association of potassium measurements and the risk of T2DM. The summary risk estimates were obtained through a random-effects model. Dose-response analysis was conducted.

Results

Eight studies involving 5,053 cases and 119,993 individuals were included. A trend toward significance was found in the highest versus lowest meta-analysis on serum potassium and T2DM risk (RR = 0.79; 95% CI 0.60-1.04); moreover, the RR per 1 mmol/L increase in serum potassium was 0.83 (95% CI 0.73-0.95). A non-significant association of dietary potassium and T2DM risk was detected (RR for the highest versus lowest category: 0.93; 95% CI 0.81-1.06; RR for every 1000mg increase per day: 1.00, 95% CI 0.96-1.05). A similar non-significant association was found for urinary potassium and T2DM risk (RR for the highest versus lowest category: 0.83; 95% CI 0.39-1.75; RR per 10 mmol increase: 1.00; 95% CI 0.95-1.05). Evidence of a linear association between serum, dietary, and urinary potassium and the risk of T2DM was found (all P_{non-linearity} > 0.05).

Conclusions

Low serum potassium increases the risk of T2DM in a linear dose-response manner; nevertheless, neither dietary potassium nor urinary potassium shows any association with the risk of T2DM. However, these findings should be interpreted with caution due to limited studies.

Glucose tolerance and insulin responsiveness in Gitelman syndrome patients

OBJECTIVE

Impaired glucose metabolism and insulin sensitivity have been reported in patients with Gitelman syndrome (GS), but insulin secretion and the related mechanisms are not well understood.

DESIGN AND METHODS

The serum glucose levels, insulin secretion and insulin sensitivity were evaluated in patients with GS (n = 28), patients with type 2 diabetes mellitus (DM) and healthy individuals (n = 20 in both groups) using an oral glucose tolerance test. Serum and urine sodium, potassium and creatinine levels were measured at 0, 30, 60, 120 and 180 min after an oral glucose load was administered.

RESULTS

The areas under the serum glucose curves were higher in the GS patients than those in the healthy controls (17.4 ± 5.1 mmol·h/L vs 14.5 ± 2.8 mmol·h/L, P = 0.02) but lower than those in the DM patients (24.8 ± 5.3 mmol·h/L, P < 0.001). The areas under the serum insulin curves and the insulin secretion indexes in GS patients were higher than those in DM patients and lower than those in healthy subjects. The insulin secretion-sensitivity index of GS patients was between that of healthy subjects and DM patients, but the insulin sensitivity indices were not different among the three groups. After one hour of glucose administration, the serum potassium level significantly decreased from baseline, and the urinary potassium-to-creatinine ratio increased gradually and peaked at 2 h.

CONCLUSIONS

Glucose metabolism and insulin secretion were impaired in GS patients, but insulin sensitivity was comparable between GS patients and patients with type 2 DM. After administration of an oral glucose load, the plasma potassium level decreased in GS patients due to the increased excretion of potassium in the urine.

Serum potassium is a predictor of incident diabetes in African Americans with normal aldosterone: the Jackson Heart Study

BACKGROUND

Low-normal potassium is a risk factor for diabetes and may account for some of the racial disparity in diabetes risk. Aldosterone affects serum potassium and is associated with insulin resistance.

OBJECTIVES

We sought to confirm the association between potassium and incident diabetes in an African-American cohort, and to determine the effect of aldosterone on this association.

DESIGN

We studied participants from the Jackson Heart Study, an African-American adult cohort, who were without diabetes at baseline. With the use of logistic regression, we characterized the associations of serum, dietary, and urinary potassium with incident diabetes. In addition, we evaluated aldosterone as a potential effect modifier of these associations.

RESULTS

Of 2157 participants, 398 developed diabetes over 8 y. In a minimally adjusted model, serum potassium was a significant predictor of incident diabetes (OR: 0.83; 95% CI: 0.74, 0.92 per SD increment in serum potassium). In multivariable models, we found a significant interaction between serum potassium and aldosterone (P = 0.046). In stratified multivariable models, in those with normal aldosterone (<9 ng/dL, n = 1163), participants in the highest 2 potassium quartiles had significantly lower odds of incident diabetes than did those in the lowest potassium quartile [OR (95% CI): 0.61 (0.39, 0.97) and 0.54 (0.33, 0.90), respectively]. Among those with high-normal aldosterone (≥9 ng/dL, n = 202), we found no significant association between serum potassium and incident diabetes. In these stratified models, serum aldosterone was not a significant predictor of incident diabetes. We found no statistically significant associations between dietary or urinary potassium and incident diabetes.

CONCLUSIONS

In this African-American cohort, we found that aldosterone may modify the association between serum potassium and incident diabetes. In participants with normal aldosterone, high-normal serum potassium was associated with a lower risk of diabetes than was low-normal serum potassium. Additional studies are warranted to determine whether serum potassium is a modifiable risk factor that could be a target for diabetes prevention. This trial was registered at clinicaltrials.gov as NCT00415415.

Medication-induced diabetes mellitus

Epidemiological studies and case reports have demonstrated an increased rate of development of diabetes mellitus consequent to taking diverse types of medication. This review explores this evidence linking these medications and development of diabetes and presents postulated mechanisms by which the medications might cause diabetes. Some medications are associated with a reduction in insulin production, some with reduction in insulin sensitivity, and some appear to be associated with both reduction in insulin production and insulin sensitivity.

Effects of potassium citrate or potassium chloride in patients with combined glucose intolerance: A placebo-controlled pilot study

BACKGROUND

Experimental K(+) depletion reversibly inhibits insulin secretion, while chronic metabolic acidosis decreases insulin sensitivity. We aimed to investigate the effects of potassium supplementation and alkali supplementation in non-acidotic, normokalemic humans with combined glucose intolerance.

STUDY DESIGN AND RESULTS

In this double-blind, placebo-controlled study in 11 subjects (7 male, 4 female, ages 47-63 years), 90meqs of oral KCl or Kcitrate per day for 2weeks each increased insulin production as measured by homeostasis model assessment Beta [KCl=86 (CI 81-91), Kcitrate=88 (82-94), placebo=78 (73-83)%, p<0.04], but only Kcitrate attenuated insulin resistance as assessed by HOMA-IR (insulin resistance, Kcitrate=2.8 (2.5-3.1), placebo=3.2 (2.9-3.5), p<0.03) and only Kcitrate increased quantitative insulin sensitivity check index (Quicki, Kcitrate=0.355 (0.305-0.405), placebo=0.320 (0.265-0.375) p<0.04). These results were confirmed by independent measurements, i.e. HOMA C-peptide and whole body insulin sensitivity index measured during oral glucose tolerance testing. Kcitrate significantly decreased systolic and diastolic 24-hour ambulatory blood pressures (-4.0 (-3 to -5) and -2.7 (-1.9 to -3.5), respectively as compared to placebo, p<0.02) while KCl was without a significant effect.

CONCLUSIONS

K(+) supplementation in the absence of overt K(+) depletion improves beta-cell function in subjects with combined glucose intolerance. The insulin-sensitizing and hypotensive effect, however, depend on citrate as the accompanying anion.

Tissue-specific regulation of potassium homeostasis by high doses of cationic amino acids

The administration of l-arginine hydrochloride has been used for testing pituitary secretion in humans, and as an experimental model for induction of acute pancreatitis in rats and mice. Whereas in the first case, the administration of the amino acid is associated with hiperkalemia, in the model of acute pancreatitis no data are available on possible changes in potassium homeostasis. The present study shows that the acute administration to mice of l-arginine hydrochloride or other cationic amino acids almost duplicate plasma potassium levels. This effect was associated to a marked decrease of tissue potassium in both pancreas and liver. No changes were found in other tissues. These changes cannot be ascribed to the large load of chloride ions, since similar effects were produced when l-ornithine aspartate was administered. The changes in potassium levels were dependent on the dose. The displacement of intracellular potassium from the liver and pancreas to the extracellular compartment appears to be dependent on the entry of the cationic amino acid, since the administration of an equivalent dose of alfa-difluoromethyl ornithine HCl (DFMO), a non physiological analog of l-ornithine, which is poorly taken by the tissues in comparison with the physiological cationic amino acids, did not produce any change in potassium levels in pancreas and liver. The analyses of the expression of cationic amino acid transporters (CAT) suggest that the CAT-2 transporter may be implicated in the potassium/cationic amino acid interchange in liver and pancreas. The possible physiological or pathological relevance of these findings is discussed.

The metabolic vascular syndrome - guide to an individualized treatment

In ancient Greek medicine the concept of a distinct syndrome (going together) was used to label 'a group of signs and symptoms' that occur together and 'characterize a particular abnormality and condition'. The (dys)metabolic syndrome is a common cluster of five pre-morbid metabolic-vascular risk factors or diseases associated with increased cardiovascular morbidity, fatty liver disease and risk of cancer. The risk for major complications such as cardiovascular diseases, NASH and some cancers develops along a continuum of risk factors into clinical diseases. Therefore we still include hyperglycemia, visceral obesity, dyslipidemia and hypertension as diagnostic traits in the definition according to the term 'deadly quartet'. From the beginning elevated blood pressure and hyperglycemia were core traits of the metabolic syndrome associated with endothelial dysfunction and increased risk of cardiovascular disease. Thus metabolic and vascular abnormalities are in extricable linked. Therefore it seems reasonable to extend the term to metabolic-vascular syndrome (MVS) to signal the clinical relevance and related risk of multimorbidity. This has important implications for integrated diagnostics and therapeutic approach. According to the definition of a syndrome the rapid global rise in the prevalence of all traits and comorbidities of the MVS is mainly caused by rapid changes in life-style and sociocultural transition resp. with over- and malnutrition, low physical activity and social stress as a common soil.

Quantifying the effects of diuretics and β-adrenoceptor blockers on glycaemic control in diabetes mellitus - a systematic review and meta-analysis

AIMS

Although there are reports that β-adrenoceptor antagonists (beta-blockers) and diuretics can affect glycaemic control in people with diabetes mellitus, there is no clear information on how blood glucose concentrations may change and by how much. We report results from a systematic review to quantify the effects of these antihypertensive drugs on glycaemic control in adults with established diabetes.

METHODS

We systematically reviewed the literature to identify randomized controlled trials in which glycaemic control was studied in adults with diabetes taking either beta-blockers or diuretics. We combined data on HbA1c and fasting blood glucose using fixed effects meta-analysis.

RESULTS

From 3864 papers retrieved, we found 10 studies of beta-blockers and 12 studies of diuretics to include in the meta-analysis. One study included both comparisons, totalling 21 included reports. Beta-blockers increased fasting blood glucose concentrations by 0.64 mmol l(-1) (95% CI 0.24, 1.03) and diuretics by 0.77 mmol l(-1) (95% CI 0.14, 1.39) compared with placebo. Effect sizes were largest in trials of non-selective beta-blockers (1.33, 95% CI 0.72, 1.95) and thiazide diuretics (1.69, 95% CI 0.60, 2.69). Beta-blockers increased HbA1c concentrations by 0.75% (95% CI 0.30, 1.20) and diuretics by 0.24% (95% CI -0.17, 0.65) compared with placebo. There was no significant difference in the number of hypoglycaemic events between beta-blockers and placebo in three trials.

CONCLUSIONS

Randomized trials suggest that thiazide diuretics and non-selective beta-blockers increase fasting blood glucose and HbA1c concentrations in patients with diabetes by moderate amounts. These data will inform prescribing and monitoring of beta-blockers and diuretics in patients with diabetes.

Pathophysiological Mechanisms and Correlates of Therapeutic Pharmacological Interventions in Essential Arterial Hypertension

Treating arterial hypertension (HT) remains a hard task. The hypertensive patient is often a subject with several comorbidities and metabolic abnormalities. Clinicians everyday have to choose the right drug for the single patient among the different classes of antihypertensives. Apart from lowering blood pressure, a main therapeutic target should be that of counteracting all the possible pathophysiological mechanisms involved in HT itself and in existing/potential comorbidities. All the ancillary positive and negative effects of the administered drugs should be considered: in particular, since hypertensive patients are often glucose intolerant/diabetic, carrier of serum lipids disorder, have already developed atherosclerotic diseases and endothelial dysfunction, they should not be treated with drugs negatively interfering with these conditions but with molecules that, if possible, improve them. The main pathophysiological mechanisms and correlates of therapeutic pharmacological interventions in essential HT are reviewed here.

A Dietary Intervention in Urban African Americans: Results of the "Five Plus Nuts and Beans" Randomized Trial

INTRODUCTION

Unhealthy diets, often low in potassium, likely contribute to racial disparities in blood pressure. We tested the effectiveness of providing weekly dietary advice, assistance with selection of higher potassium grocery items, and a $30 per week food allowance on blood pressure and other outcomes in African American adults with hypertension.

DESIGN

We conducted an 8-week RCT with two parallel arms between May 2012 and November 2013.

SETTING/PARTICIPANTS

We randomized 123 African Americans with controlled hypertension from an urban primary care clinic in Baltimore, Maryland, and implemented the trial in partnership with a community supermarket and the Baltimore City Health Department. Mean (SD) age was 58.6 (9.5) years; 71% were female; blood pressure was 131.3 (14.7)/77.2 (10.5) mmHg; BMI was 34.5 (8.2); and 28% had diabetes.

INTERVENTION

Participants randomized to the active intervention group (Dietary Approaches to Stop Hypertension [DASH]-Plus) received coach-directed dietary advice and assistance with weekly online ordering and purchasing of high-potassium foods ($30/week) delivered by a community supermarket to a neighborhood library. Participants in the control group received a printed DASH diet brochure along with a debit account of equivalent value to that of the DASH-Plus group.

MAIN OUTCOME MEASURES

The primary outcome was blood pressure change. Analyses were conducted in January to October 2014.

RESULTS

Compared with the control group, the DASH-Plus group increased self-reported consumption of fruits and vegetables (mean=1.4, 95% CI=0.7, 2.1 servings/day); estimated intake of potassium (mean=0.4, 95% CI=0.1, 0.7 grams/day); and urine potassium excretion (mean=19%, 95% CI=1%, 38%). There was no significant effect on blood pressure.

CONCLUSIONS

A program providing dietary advice, assistance with grocery ordering, and $30/week of high-potassium foods in African American patients with controlled hypertension in a community-based clinic did not reduce BP. However, the intervention increased consumption of fruits, vegetables, and urinary excretion of potassium.

Transethnic meta-analysis suggests genetic variation in the HEME pathway influences potassium response in patients treated with hydrochlorothiazide

Hypokalemia is a recognized adverse effect of thiazide diuretic treatment. This phenomenon, which may impair insulin secretion, has been suggested to be a reason for the adverse effects on glucose metabolism associated with thiazide diuretic treatment of hypertension. However, the mechanisms underlying thiazide diuretic-induced hypokalemia are not well understood. In an effort to identify genes or genomic regions associated with potassium response to hydrochlorothiazide, without a priori knowledge of biologic effects, we performed a genome-wide association study and a multiethnic meta-analysis in 718 European- and African-American hypertensive participants from two different pharmacogenetic studies. Single-nucleotide polymorphisms rs10845697 (Bayes factor=5.560) on chromosome 12, near to the HEME binding protein 1 gene, and rs11135740 (Bayes factor=5.258) on chromosome 8, near to the Mitoferrin-1 gene, reached genome-wide association study significance (Bayes factor >5). These results, if replicated, suggest a novel mechanism involving effects of genes in the HEME pathway influencing hydrochlorothiazide-induced renal potassium loss.

Personalizing the diuretic treatment of hypertension: the need for more clinical and research attention

Neither randomized controlled trials nor efforts to identify genetic markers have been helpful with regard to the goal of individualizing diuretic therapy in the treatment of hypertension, a goal that receives little clinical or research attention. This review will examine, and bring attention to, the considerable yet overlooked information relevant to individualizing diuretic therapy. It will bring attention to clinical, biochemical, and pharmacological clues that can be helpful in identifying who is likely to respond to a diuretic, who needs a stronger diuretic regimen, which diuretic to prescribe, and how to minimize adverse effects. New directions for clinical research aimed at individualizing use in hypertension will be explored. Research and clinical attention to the goal of individualizing diuretic treatment in hypertension need to be renewed, to help us achieve greater hypertension control with fewer adverse effects and lower costs.

The glycemic effects of antihypertensive medications

Older antihypertensive medications are believed to be associated with metabolic disturbances, especially raised glucose levels. Owing to this, many physicians shun their use. Newer antihypertensive medications are metabolically neutral or metabolically favorable; therefore, they are looked upon favorably and are chosen as primary medications for the treatment of hypertension. Here we review the literature on the glucose effects of older and newer antihypertensive medications. We also consider what, if any, impact these metabolic effects have on cardiovascular disease outcomes. We show that the diabetogenic effects of thiazide diuretics and beta blockers are small relative to the glucose effects of angiotensin-converting enzyme inhibitors (ACEIs) and calcium channel blockers, and that over time, the glucose differences between older and newer medications diminish. Importantly, we show that the diabetogenic effects of older antihypertensive medications do not translate into increased cardiovascular disease risk.

Antihypertensive drugs and glucose metabolism

Hypertension plays a major role in the development and progression of micro- and macrovascular disease. Moreover, increased blood pressure often coexists with additional cardiovascular risk factors such as insulin resistance. As a result the need for a comprehensive management of hypertensive patients is critical. However, the various antihypertensive drug categories have different effects on glucose metabolism. Indeed, angiotensin receptor blockers as well as angiotensin converting enzyme inhibitors have been associated with beneficial effects on glucose homeostasis. Calcium channel blockers (CCBs) have an overall neutral effect on glucose metabolism. However, some members of the CCBs class such as azelnidipine and manidipine have been shown to have advantageous effects on glucose homeostasis. On the other hand, diuretics and β-blockers have an overall disadvantageous effect on glucose metabolism. Of note, carvedilol as well as nebivolol seem to differentiate themselves from the rest of the β-blockers class, being more attractive options regarding their effect on glucose homeostasis. The adverse effects of some blood pressure lowering drugs on glucose metabolism may, to an extent, compromise their cardiovascular protective role. As a result the effects on glucose homeostasis of the various blood pressure lowering drugs should be taken into account when selecting an antihypertensive treatment, especially in patients which are at high risk for developing diabetes.

Translation and validation of the dietary approaches to stop hypertension for koreans intervention: culturally tailored dietary guidelines for Korean Americans with high blood pressure

BACKGROUND

Lifestyle modification strategies such as adoption of the Dietary Approaches to Stop Hypertension (DASH) diet are now recognized as an integral part of high blood pressure (HBP) management. Although the high prevalence of HBP among Korean Americans (KAs) is well documented, few dietary interventions have been implemented in this population, in part because of a lack of culturally relevant nutrition education guidelines. Translating and testing the efficacy of culturally relevant dietary recommendations using a well-established dietary guideline such as DASH are imperative for promoting better cardiovascular health for this high-risk cultural group.

OBJECTIVE

The aims of this study were to systematically translate and validate a culturally modified DASH for Koreans (K-DASH) and obtain preliminary evidence of efficacy.

METHODS

A 2-step approach of intervention translation and efficacy testing, together with close adherence to principles of community-based participatory research, was used to maximize community input. A 1-group pre-post design with 24-hour urine and 24-hour ambulatory blood pressure monitoring comparisons was used to test the initial feasibility and efficacy of the K-DASH intervention.

RESULTS

A total of 28 KAs with HBP participated in a 10-week dietary intervention consisting of group education sessions and individual counseling. Both systolic blood pressure and diastolic blood pressure, as measured by ambulatory blood pressure monitoring, were significantly decreased at postintervention evaluation (systolic blood pressure, -4.5 mm Hg; diastolic blood pressure, -2.6 mm Hg; P < .05). Serum low-density lipoprotein cholesterol was significantly decreased (-7.3 mg/dL; P < .05). Serum potassium and ascorbic acid levels were also improved in the reference range. Urine potassium level was significantly increased, supporting increased fruit and vegetable consumption.

CONCLUSION

This pilot study has (a) demonstrated that a cultural adaptation of DASH using community-based participatory research methodology produced a culturally relevant and efficacious dietary intervention for the KAs with HBP and (b) provided strong preliminary evidence for the efficacy of the K-DASH intervention in reducing HBP in hypertensive KAs.

Potassium and glucose measures in older adults: the Cardiovascular Health Study

BACKGROUND

We sought to determine the impacts of serum and dietary potassium measures on glucose metabolism and diabetes risk in older adults.

METHODS

Among participants of the Cardiovascular Health Study, a community-based cohort of older American adults, we examined a) cross-sectional associations between potassium and measures of insulin sensitivity and secretion estimated from oral glucose tolerance tests and b) longitudinal associations of serum and dietary potassium with diabetes risk.

RESULTS

Among 4,754 participants aged ≥65 years at baseline, there were 445 cases of incident diabetes during a median follow-up of 12 years. In multivariate models, baseline serum and dietary potassium were both associated with lower insulin sensitivity and greater insulin secretion. Compared with those with a serum potassium ≥4.5 mEq/L, participants with a serum potassium <4.0mEq/L had an adjusted mean difference in Matsuda insulin sensitivity index of -0.18 (-0.39, 0.02). Compared with those in the highest quartile, participants in the lowest quartile of dietary potassium intake had a corresponding adjusted mean difference in Matsuda insulin sensitivity index of -0.61 (-0.94, -0.29). In multivariate models, neither serum nor dietary potassium intake was associated with long-term diabetes risk.

CONCLUSIONS

Although we did not identify serum and dietary potassium as risk factors for incident diabetes in older adults, results from cross-sectional analyses suggest that both may be associated with increased insulin resistance. This relationship with insulin resistance needs to be confirmed, and its importance on diabetes risk, cardiovascular risk, and conditions specific to older adults should be determined as well.

Cardiovascular drugs that increase the risk of new-onset diabetes

The prevalence of type 2 diabetes is increasing worldwide, and diabetes is a strong adverse prognostic factor among patients with cardiovascular (CV) disease. Four classes of drugs that are commonly used for CV risk reduction, statins, niacin, thiazide diuretics, and ß-blockers, have been shown to increase the risk of new-onset diabetes (NOD) by 9% to 43% in meta-analyses or large-scale clinical trials. Clinical predictors for drug-related NOD appear to be similar to the predictors that have been described for NOD unrelated to drugs: fasting blood glucose >100 mg/dL and features of the metabolic syndrome such as body mass index >30 kg/m(2), serum triglycerides >150 mg/dL, and elevated blood pressure, among others. The mechanisms whereby these drugs increase the risk of NOD are incompletely understood, although different hypotheses have been suggested. Lifestyle intervention consisting of diet and exercise has been shown in multiple studies to reduce the risk of NOD by approximately 50%, with persistent benefit during long-term follow-up. In patients at high risk for NOD, niacin should be avoided, and for hypertension, an angiotensin-converting enzyme inhibitor or even a ß1-selective blocker might be a better choice than a standard ß-blocker. For thiazide diuretics and particularly statins, benefit in terms of CV event reduction outweighs the risk of NOD.

Serum potassium is an age-dependent risk factor for pre-diabetes and diabetes in the Israeli population

OBJECTIVE

We analysed the association between serum potassium, within the normal range, and early signs of diabetes in an Israeli population.

RESEARCH DESIGN AND METHODS

A computerized database of the Clalit Health Services was used for obtaining information regarding patients' baseline serum potassium levels. The main study outcome was dysglycaemia, defined as fasting glucose > 100 mg/dL, HbA1C > 6.5 gr% (48 mmol/mol) or a new diagnosis of diabetes. A secondary outcome was overt diabetes.

RESULTS

Included in the study were 71,597 patients, mean age 40.8 ± 13.4 years. After a mean follow-up period of 5.3 ± 2.2 years, dysglycaemia decreased [odds ratio (OR) = 0.95; 95% confidence interval (CI) = 0.906-0.997; p = 0.038], as did the incidence of overt diabetes (OR = 0.86; 95% CI = 0.793-0.934; p = 0.0001), for every 1 mmol/L elevation in serum potassium in the normal range. But analysis of subpopulation reveals that when elevated serum potassium was associated with low adjusted ORs for predicting dysglycaemia (OR = 0.904 with a 95% CI of 0.849-0.963; p = 0.002), the opposite effect was demonstrated over the age of 41 years (OR = 1.113 with a 95% CI of 1.048-1.104; p < 0.001).

CONCLUSIONS

This study demonstrates age-related association between serum potassium and the risk of dysglycaemia.

Non-traditional risk factors are important contributors to the racial disparity in diabetes risk: the atherosclerosis risk in communities study

BACKGROUND

Traditional risk factors, particularly obesity, do not completely explain the excess risk of diabetes among African Americans compared to whites.

OBJECTIVE

We sought to quantify the impact of recently identified, non-traditional risk factors on the racial disparity in diabetes risk.

DESIGN

Prospective cohort study.

PARTICIPANTS

We analyzed data from 2,322 African-American and 8,840 white participants without diabetes at baseline from the Atherosclerosis Risk in Communities (ARIC) Study.

MAIN MEASURES

We used Cox regression to quantify the association of incident diabetes by race over 9 years of in-person and 17 years of telephone follow-up, adjusting for traditional and non-traditional risk factors based on literature search. We calculated the mediation effect of a covariate as the percent change in the coefficient of race in multivariate models without and with the covariate of interest; 95 % confidence intervals (95 % CI) were calculated using boot-strapping.

KEY RESULTS

African American race was independently associated with incident diabetes. Body mass index (BMI), forced vital capacity (FVC), systolic blood pressure, and serum potassium had the greatest explanatory effects for the difference in diabetes risk between races, with mediation effects (95 % CI) of 22.0 % (11.7 %, 42.2 %), 21.7 %(9.5 %, 43.1 %), 17.9 % (10.2 %, 37.4 %) and 17.7 % (8.2 %, 39.4 %), respectively, during 9 years of in-person follow-up, with continued effect over 17 years of telephone follow-up.

CONCLUSIONS

Non-traditional risk factors, particularly FVC and serum potassium, are potential mediators of the association between race and diabetes risk. They should be studied further to verify their importance and to determine if they mark causal relationships that can be addressed to reduce the racial disparity in diabetes risk.

Statins and renin-angiotensin system inhibitor combination treatment to prevent cardiovascular disease

Hypercholesterolemia and hypertension are common risk factors for cardiovascular disease (CVD). Updated guidelines emphasize target reductions of overall cardiovascular risks. Experimental studies have shown reciprocal relationships between insulin resistance (IR) and endothelial dysfunction. Hypercholesterolemia and hypertension have a synergistic deleterious effect on IR and endothelial dysfunction. Unregulated renin-angiotensin system (RAS) is important in the pathogenesis of atherosclerosis and hypertension. Various strategies with different classes of antihypertensive medications to reach target goals have failed to reduce residual CVD risk further. Of interest, treating moderate cholesterol elevations with low-dose statins in hypertensive patients reduced CVD risk by 35-40% further. Therefore, statins are important in reducing CVD risk. Unfortunately, statin therapy causes IR and increases the risk of type 2 diabetes mellitus. RAS inhibitors improve both endothelial dysfunction and IR. Further, cross-talk between hypercholesterolemia and RAS exists at multiple steps of IR and endothelial dysfunction. In this regard, combined therapy with statins and RAS inhibitors demonstrates additive/synergistic effects on endothelial dysfunction and IR in addition to lowering cholesterol levels and blood pressure when compared with either monotherapy in patients. This is mediated by both distinct and interrelated mechanisms. Therefore, combined therapy with statins and RAS inhibitors may be important in developing optimal management strategies in patients with hypertension, hypercholesterolemia, diabetes, metabolic syndrome, or obesity to prevent CVD.  

Impaired fasting glucose in hypertensive patients: prevalence and cross-sectional analysis of associations with cardiovascular disease

BACKGROUND

Impaired fasting glucose (IFG) is frequently present in hypertensive patients and might be induced or aggravated by antihypertensive treatment. However, it is unclear whether IFG is associated with increased cardiovascular risk in this population.

PATIENTS AND METHODS

We performed a cross-sectional study in 1,810 hypertensive patients and recorded the presence of IFG, coronary heart disease (CHD), and ischemic stroke.

RESULTS

IFG was present in 567 patients (31.3%). The prevalence of CHD or ischemic stroke did not differ between patients with IFG and in patients with serum glucose levels <100 mg/dL. Among patients with IFG, 267 (47.0%) were on β-blockers, diuretics, or both β-blockers and diuretics. The prevalence of CHD was numerically but not significantly higher in patients with IFG treated with β-blockers or both β-blockers and diuretics than in patients with IFG treated with diuretics or not treated with either β-blockers or diuretics and patients with serum glucose levels <100 mg/dL (11.1%, 13.6%, 1.4%, 3.7%, and 5.9%, respectively; P=not significant). The prevalence of ischemic stroke did not differ among these groups.

CONCLUSIONS

IFG does not appear to be associated with increased prevalence of cardiovascular disease in hypertensive patients, regardless if it is associated with the antihypertensive treatment or not.

Which is a better treatment for hypertensive patients with diabetes: a combination of losartan and hydrochlorothiazide or a maximum dose of losartan?

BACKGROUND

This 12-month study compared the effects of a combination of losartan 50 mg and hydrochlorothiazide 12.5 mg with a maximum dose of losartan (100 mg) in hypertensive patients with diabetes.

METHODS

This was a multicenter randomized open-label study.

RESULTS

A similar reduction in systolic/diastolic blood pressure from baseline to month 3 was observed in both groups. There was also a similar decrease in UACR in both groups. A significant decrease in uric acid was observed in the maximum-dose group only. eGFR decreased in the combination group after 1 year.

CONCLUSIONS

The combination of losartan and a diuretic may be a useful option in such hypertensive patients with diabetes, provided that metabolic parameters are closely monitored. In patients with hyperuricemia and impaired renal function, a maximum dose of losartan may be more beneficial.