Antihypertensive medications: benefits of blood pressure lowering and hazards of metabolic effects

Antihypertensive Effects of Aqueous Extract of Ricinodendron heudelotii (Baill.) Pierre (Euphorbiaceae) in Wistar Rat

Ricinodendron heudelotii stem bark is commonly used in Cameroonian traditional medicine to treat cardiovascular diseases such as hypertension. The present study was designed to investigate the antihypertensive and antioxidant properties of the aqueous extract of Ricinodendron heudelotii in salt-induced hypertensive rats. Analysis by HPLC-ESI-Q-TOF-MS was used to identify various chemical components of the extract. A total of thirty rats were used for each test. High-salt hypertension was induced in rats by oral administration of NaCl for 12 weeks. Mean blood pressure (MBP) and heart rate (HR) were monitored by noninvasive methods. Oral administration of Ricinodendron heudelotii significantly ( $p<0.01$ ) reduced the increase of mean blood pressure (23.12%, 26.14%, and 24.34%) and heart rate (31.19%, 31.09%, and 26.98%), respectively, at the doses of 40, 20, and 6 mg/kg, compared to the hypertensive group. All the doses tested significantly reduced or/and ameliorated biochemical and oxidative stress parameters. Histological analysis showed that Ricinodendron heudelotii restored renal disorders induced by the administration of salt. The aqueous extract of Ricinodendron heudelotii exerts a cardioprotective effect, and the antihypertensive activity seems associated with an improvement in antioxidant status. Overall, the results justify and support the traditional use of Ricinodendron heudelotii.

Role of the gut microbiome in cardiovascular drug response: The potential for clinical application

Response to cardiovascular drugs can vary greatly between individuals, and the role of the microbiome in this variability is being increasingly appreciated. Recent evidence indicates that bacteria and other microbes are responsible for direct and indirect effects on drug efficacy and toxicity. Pharmacomicrobiomics aims to uncover variability in drug response due to microbes in the human body, which may alter drug disposition through microbial metabolism, interference by microbial metabolites, or modification of host enzymes. In this review, we present recent advances in our understanding of the interplay between microbes, host metabolism, and cardiovascular drugs. We report numerous cardiovascular drugs with evidence of, or potential for, gut-microbe interactions. However, the effects of gut microbiota on many cardiovascular drugs are yet uninvestigated. Finally, we consider potential clinical applications for the described findings.

A Validated RP-HPLC Stability Method for the Estimation of Chlorthalidone and Its Process-Related Impurities in an API and Tablet Formulation

Low-dose thiazide and thiazide-like diuretics are widely used as first-line therapy for hypertension. Chlorthalidone, a monosulfamyl diuretic, is frequently prescribed in cases of hypertension and congestive heart failure. In this research paper, an improved reverse-phase HPLC method was developed for the simultaneous identification and quantitation of pharmacopoeia-listed and in-house process- and degradation-related impurities of chlorthalidone in bulk drug and formulations. Chromatographic separation was carried out on a C₈ column (250 × 4.6 mm; '5 μm particle size) at a flow rate of 1.4 mL/min with a 220 nm detection wavelength. Mobile phase A consisted of buffer solution (diammonium hydrogen orthophosphate (10 mM, pH 5.5)) and methanol at a 65 : 35 ratio (v/v), and mobile phase B consisted of buffer solution and methanol at a 50 : 50 ratio (v/v). The API and formulation were subjected to stress conditions such as acid, alkali, oxidation, thermal, and photolytic conditions. Validation studies for the in-house process impurities were performed for specificity, limit of detection (LOD), limit of quantitation (LOQ), linearity, precision, accuracy, and robustness. Thus, an improved RP-HPLC method capable of good separation of all known and unknown impurities with acceptable resolution and tailing factor was developed.

Visually guided classification trees for analyzing chronic patients

Background

Chronic diseases are becoming more widespread each year in developed countries, mainly due to increasing life expectancy. Among them, diabetes mellitus (DM) and essential hypertension (EH) are two of the most prevalent ones. Furthermore, they can be the onset of other chronic conditions such as kidney or obstructive pulmonary diseases. The need to comprehend the factors related to such complex diseases motivates the development of interpretative and visual analysis methods, such as classification trees, which not only provide predictive models for diagnosing patients, but can also help to discover new clinical insights.

Results

In this paper, we analyzed healthy and chronic (diabetic, hypertensive) patients associated with the University Hospital of Fuenlabrada in Spain. Each patient was classified into a single health status according to clinical risk groups (CRGs). The CRGs characterize a patient through features such as age, gender, diagnosis codes, and drug codes. Based on these features and the CRGs, we have designed classification trees to determine the most discriminative decision features among different health statuses. In particular, we propose to make use of statistical data visualizations to guide the selection of features in each node when constructing a tree. We created several classification trees to distinguish among patients with different health statuses. We analyzed their performance in terms of classification accuracy, and drew clinical conclusions regarding the decision features considered in each tree. As expected, healthy patients and patients with a single chronic condition were better classified than patients with comorbidities. The constructed classification trees also show that the use of antipsychotics and the diagnosis of chronic airway obstruction are relevant for classifying patients with more than one chronic condition, in conjunction with the usual DM and/or EH diagnoses.

Conclusions

We propose a methodology for constructing classification trees in a visually guided manner. The approach allows clinicians to progressively select the decision features at each of the tree nodes. The process is guided by exploratory data analysis visualizations, which may provide new insights and unexpected clinical information.

Antihypertensive effects of the hydro-ethanol extract of Senecio serratuloides DC in rats

BACKGROUND

Senecio serratuloides DC is used in folk medicine for treating hypertension, skin disorders, internal and external sores, rashes, burns and wounds. This study aimed at investigating the antihypertensive effects of the hydroethanol extract of S. serratuloides (HESS) in N-Nitro-L-arginine methyl ester (L-NAME) induced hypertension in rats.

METHODS

Acute toxicity of HESS was first determined to provide guidance on doses to be used in this study. Lorke's method was used to determine safety of the extract in mice. Female Wistar rats were treated orally once daily with L-NAME (40 mg/kg) for 4 weeks and then concomitantly with L-NAME (20 mg/kg) and plant extract (150 and 300 mg/kg), captopril (20 mg/kg) or saline as per assigned group for 2 weeks followed by a 2-week period of assigned treatments only. Blood pressure was monitored weekly. Lipid profile, nitric oxide, renin and angiotensin II concentrations were determined in serum while mineralocorticoid receptor concentration was quantified in the kidney homogenate. Nitric oxide (NO) concentration was determined in serum and cardiac histology performed.

RESULTS

HESS was found to be non-toxic, having a LD50 greater than 5000 mg/kg. Blood pressure increased progressively in all animals from the second week of L-NAME treatment. HESS treatment significantly and dose-dependently lowered systolic blood pressure (p < 0.001), diastolic blood pressure (p < 0.01), low density lipoprotein cholesterol (p < 0.01) and triglycerides (p < 0.01). It significantly prevented L-NAME induced decrease in serum angiotensin II (p < 0.01), high density lipoprotein cholesterol (p < 0.001) and serum nitric oxide concentrations (p < 0.001). HESS also significantly (p < 0.01) prevented collagen deposition in cardiac tissue.

CONCLUSION

The hydro-ethanol extract of Senecio serratuloides showed antihypertensive, antihyperlipidemic and cardioprotective effects in rats thus confirming its usefulness in traditional antihypertensive therapy and potential for antihypertensive drug development.

Country Characteristics and Variation in Diabetes Prevalence among Asian Countries - an Ecological Study

Objectives

To determine the variation in diabetes prevalence across Asian countries and its relationship with the quality of health system and socioeconomic characteristics of the country.

Methodology

An ecological analysis was conducted using publicly available data from the World Bank, the World Health Organization and the International Diabetes Federation. Geographical variation in diabetes prevalence across countries was examined using control charts while the relationships between country-level determinants and diabetes prevalence were investigated using linear regression analysis.

Results

The control chart shows special-cause variation in diabetes prevalence in 21 (58%) of the Asian countries; nine countries were below the 99.8% control limits while twelve were above it.Fifteen (42%) countries suggest common-cause variation. Three country characteristics independently associated with diabetes prevalence were hypertension prevalence (OR 0.39, 95% CI 0.22 to 0.55; p-value<0.001), obesity prevalence (OR 0.15, 95% CI 0.13 to 0.18; p-value<0.001), and quality of health care governance (OR 0.18, 95% CI 0.04 to 0.34; p-value=0.02).

Conclusions

There is a considerable geographical variation in diabetes prevalence across Asian countries. A substantial part of this variation could be explained by differences in the quality of health care governance, hypertension prevalence and obesity prevalence.

Higher levels of thioredoxin interacting protein (TXNIP) in patients with prediabetes compared to obese normoglycemic subjects

BACKGROUND

Thioredoxin interacting protein (TXNIP) is one of the mediators of oxidative stress induced beta-cell glucotoxisity. TXNIP might play a key role in impaired glucose homeostasis preceding overt T2DM. The aim of the present study was to compare TXNIP levels between patients with prediabetes and obese normoglycemic controls and to evaluate the link between TXNIP and metabolic risk factors.

PATIENTS AND METHODS

In the present study we included 79 patients with mean age 50.3 ± 10.6 years, divided into two age and BMI matched groups -control group with obesity without glycemic disturbances (NGT) (n = 40) and prediabetes (n = 39).

RESULTS

We found significantly higher levels of TXNIP in patients with prediabetes compared to normoglycemic obese controls (54.2 ± 69.9 vs. 23.9 ± 47.1 pg/ml; p = 0.03). The levels of TXNIP gradually increased from normal glucose tolerance trough IFG/IGT only to IFG + IGT (27,1; 44.0; 49.9 and 95.7 pg/ml respectively; p = 0.025 between NGT and IFG + IGT). TXNIP levels correlated weakly only with fasting blood glucose (r = 0.235; p = 0.04) but not with glucose during OGTT or the markers of insulin resistance.

CONCLUSIONS

The levels of TXNIP are higher in patients with prediabetes compared to normoglycemic controls as they increase gradually from NGT trough IFG/IGT only to IFG + IGT.

Comorbidity Status and Annual Total Medical Expenditures in U.S. Hypertensive Adults

INTRODUCTION

The purpose of this study is to investigate comorbidity status and its impact on total medical expenditures in non-institutionalized hypertensive adults in the U.S.

METHODS

Data from the 2011-2014 Medical Expenditure Panel Survey were used. Patients were included if they had a diagnosis code for hypertension, were aged ≥18 years, and were not pregnant during the study period (N=26,049). The Elixhauser Comorbidity Index was modified to add hypertension-related comorbidities. The outcome variable was annual total medical expenditures, and a generalized linear model regression (gamma distribution with a log link function) was used. All costs were adjusted to 2014 U.S. dollars.

RESULTS

Based on the modified Elixhauser Comorbidity Index, 14.0% of patients did not have any comorbidities, 23.0% had one, 24.4% had two, and 38.7% had three or more. The five most frequent comorbidities were hyperlipidemia, diabetes, rheumatoid arthritis, depression, and chronic pulmonary disease. Estimated mean annual total medical expenditures were $3,914 (95% CI=$3,456, $4,372) for those without any comorbidity; $5,798 (95% CI=$5,384, $6,213) for those with one comorbidity; $8,333 (95% CI=$7,821, $8,844) for those with two comorbidities; and $13,920 (95% CI=$13,166, $14,674) for those with three or more comorbidities. Of the 15 most frequent comorbidities, the condition with the largest impact on expenditures for an individual person was congestive heart failure ($7,380). Hypertensive adults with stroke, coronary heart disease, diabetes, renal diseases, and hyperlipidemia had expenditures that were $6,069, $6,046, $5,039, $4,974, and $4,851 higher, respectively, than those without these conditions.

CONCLUSIONS

Comorbidities are highly prevalent among hypertensive adults, and this study shows that each comorbidity significantly increases annual total medical expenditures.

Systolic Blood Pressure and Risk of Type 2 Diabetes: A Mendelian Randomization Study

Observational studies have shown that elevated systolic blood pressure (SBP) is associated with future onset of type 2 diabetes, but whether this association is causal is not known. We applied the Mendelian randomization framework to evaluate the causal hypothesis that elevated SBP increases risk for type 2 diabetes. We used 28 genetic variants associated with SBP and evaluated their impact on type 2 diabetes using a European-centric meta-analysis comprising 37,293 case and 125,686 control subjects. We found that elevation of SBP levels by 1 mmHg due to our genetic score was associated with a 2% increase in risk of type 2 diabetes (odds ratio 1.02, 95% CI 1.01-1.03, P = 9.05 × 10^-5). To limit confounding, we constructed a second score based on 13 variants exclusively associated with SBP and found a similar increase in type 2 diabetes risk per 1 mmHg of genetic elevation in SBP (odds ratio 1.02, 95% CI 1.01-1.03, P = 1.48 × 10^-3). Sensitivity analyses using multiple, alternative causal inference measures and simulation studies demonstrated consistent association, suggesting robustness of our primary observation. In line with previous reports from observational studies, we found that genetically elevated SBP was associated with increased risk for type 2 diabetes. Further work will be required to elucidate the biological mechanism and translational implications.

Common Medications Which Lead to Unintended Alterations in Weight Gain or Organ Lipotoxicity

Obesity is one of the most common chronic conditions in the world. Its management is difficult, partly due to the multiple associated comorbidities including fatty liver, diabetes, hypertension, and hyperlipidemia. As a result, the choice of prescription medications in overweight and obese patients has important implications as some of them can actually worsen the fat accumulation and its associated metabolic complications. Several prescription medications are associated with weight gain with mechanisms that are often poorly understood and under-recognized. Even less data are available on the distribution of fat and lipotoxicity (the organ damage related to fat accumulation). The present review will discuss the drugs associated with weight gain, their mechanism of action, and the magnitude and timing of their effect.

Alteration in fasting glucose after prolonged treatment with a thiazide diuretic

AIMS

Thiazide diuretics are recommended as first line antihypertensive treatment, but may contribute to new onset diabetes. We aimed to describe change in fasting glucose (FG) during prolonged thiazide treatment in an observational setting.

METHODS

We conducted an observational, non-randomized, open label, follow-up study of the Pharmacogenomic Evaluation of Antihypertensive Responses (PEAR) and PEAR-2 studies. We enrolled previous participants from the PEAR or PEAR-2 studies with at least 6 months of continuous treatment with either hydrochlorothiazide (HCTZ) or chlorthalidone. Linear regression was used to identify associations with changes in FG after prolonged thiazide and thiazide-like diuretic treatment.

RESULTS

A total of 40 participants were included with a mean 29 (range 8-72) months of thiazide treatment. FG increased 6.5 (SD 13.0) mg/dL during short-term thiazide treatment and 3.6 (SD 15.3) mg/dL FG during prolonged thiazide treatment. Increased FG at follow-up was associated with longer thiazide treatment duration (β=0.34, p=0.008) and lower baseline FG (β=-0.46, p=0.02). β blocker treatment in combination with prolonged thiazide diuretic treatment was also associated with increased FG and increased 2-h glucose obtained from OGTT.

CONCLUSIONS

Our results indicate that prolonged thiazide treatment duration is associated with increased FG and that overall glycemic status worsens when thiazide/thiazide-like diuretics are combined with β blockers.

Anti-hypertensive drugs in children and adolescents

Worldwide the prevalence of essential hypertension in children and adolescents continues to increase. Traditionally providers have used “off-label” drugs to treat pediatric hypertension, meaning that rigorous clinical trials of these drugs have not been specifically performed in pediatric patient populations. Consequently providers have extrapolated dosing, safety and efficacy from trials in adults. This practice is sub-optimal as children demonstrate unique differences in drug metabolism and response. Use of unstudied or understudied drugs increases risk of adverse events and/or can lead to sub-optimal efficacy. Recognizing these concerns, regulatory agencies have created financial incentives for industry to conduct pediatric clinical trials. These incentives, coupled with the emerging pediatric hypertension epidemic, have spurred over 30 clinical trials of anti-hypertensive drugs over the past 15 years and have resulted in labeling of 10 new drugs by the United States Food and Drug Administration for treatment of hypertension in children and adolescents. Unfortunately the financial incentive structures focus on newer drugs and drug classes. Consequently there is now a relative dearth of trial data for older but sometimes commonly prescribed pediatric antihypertensive drugs. This article reviews recent pediatric antihypertensive drug trials with a focus on trial design and endpoints, drug dosing, safety, efficacy and specific drug indications. We also review the available data and experience for some of the more commonly prescribed, but less well studied “older” pediatric antihypertensive drugs.

Utilization of glucose, blood pressure, and lipid lowering medications among people with type II diabetes in the United States, 1999-2010

PURPOSE

Changes in relation to drug treatment to various control targets for diabetes were studied using the National Health and Nutrition Examination Survey, 1999-2010.

METHODS

Data on 3094 participants aged 20 years or older with diagnosed type II diabetes were analyzed. Use of medications for lowering glucose, blood pressure, and lipids in the past month was assessed by questionnaire. Data from two survey cycles were combined together to produce estimates for each 4-year period.

RESULTS

Usage of metformin increased from 34.8% to 53.8% and was the most prevalent medications during this period (P < .001), and half of subjects taking metformin could achieve glycated hemoglobin less than 7.0% in 2007-2010. Dipeptidyl peptidase-4 inhibitors were used by 7.4% of participants in 2007-2010. Usage of angiotensin receptor blockers and beta-blockers increased significantly from 7.4% to 21.4% and from 15.3% to 31.8%, respectively from 1999 to 2010 (P ≤ .001). A total of 64.7% of participants could attain blood pressure control by 2007-2010. Usage of statins doubled in 1999-2010 and 52.2% of subjects took statins by 2007-2010 (P < .001).

CONCLUSIONS

Metformin is the first-line drug for diabetes while dipeptidyl peptidase-4 inhibitors started to be used since 2007. Blood pressure control improved in 1999-2010 partly due to increased drug prescriptions. Although statins were widely used about half of the participants did not take them.

The metabolic cost of lowering blood pressure with hydrochlorothiazide

BACKGROUND

The landmark Antihypertensive and Lipid-Lowering treatment to prevent Heart Attack Trial (ALLHAT) placed a new spotlight on thiazide diuretics as the first-line therapy for hypertension. This is concerning as thiazide-diuretics may contribute to comorbidities associated with the current epidemic of obesity. Previous randomized clinical trials have linked thiazide diuretic treatment to insulin resistance, metabolic syndrome, and increased incidence of type 2 diabetes.

METHODS

This proof of concept, longitudinal, randomized, double-blind study evaluated the effects of the angiotensin II receptor blocker Valsartan and the specific thiazide diuretic Hydrochlorothiazide (HCTZ) on hepatic triglyceride level (primary outcome), as well as triglyceride levels within other organs including the heart, skeletal muscle, and pancreas. Additionally, we evaluated whether myocardial function, insulin sensitivity, and insulin secretion were affected by these treatments.

RESULTS

Hepatic TG levels increased by 57% post HCTZ treatment: ∆hTG HCTZ = 4.12% and remained unchanged post Valsartan treatment: ∆hTG V = 0.06%. The elevation of hepatic TG levels after HCTZ treatment was additionally accompanied by a reduction in insulin sensitivity: ∆SI HCTZ = -1.14. Treatment with Valsartan resulted in improved insulin sensitivity: ∆SI V = 1.24. Treatment-induced changes in hepatic TG levels and insulin sensitivity were statistically significant between groups (phTG = 0.0098 and pSI = 0.0345 respectively). Disposition index, DI, remained unchanged after HCTZ treatment: ∆DI HCTZ = -141 but it was increased by a factor of 2 after treatment with Valsartan: ∆DI V =1018). However, the change between groups was not statistically significant. Both therapies did not modify abdominal visceral and subcutaneous fat mass as well as myocardial structure and function. Additionally, myocardial, pancreatic, and skeletal muscle triglyceride deposits remained unchanged in both therapeutic arms.

CONCLUSIONS

Our findings are two-fold and relate to hepatic steatosis and insulin sensitivity. HCTZ treatment worsened hepatic steatosis measured as hepatic triglyceride content and reduced insulin sensitivity. Valsartan treatment did not affect hepatic triglyceride levels and improved insulin sensitivity. The results of this study reinforce the message that in patients at risk for type 2 diabetes it is particularly important to choose an antihypertensive regimen that lowers blood pressure without exacerbating patient's metabolic profile.

Antihypertensive drug class interactions and risk for incident diabetes: a nested case-control study

BACKGROUND

We aimed to determine how single and combination antihypertensive therapy alters risk for diabetes mellitus (DM).Thiazide diuretics (TD), β blockers (BB), and renin-angiotensin system blockers (RASB) impact DM risk while calcium channel blockers (CCB) are neutral. DM risk associated with combinations is unclear.

METHODS AND RESULTS

We enrolled nondiabetic patients from Kaiser Permanente Northwest with a fasting plasma glucose (FPG) <126 mg/dL between 1997 and 2010. DM cases were defined by a FPG ≥ 126 mg/dL, random plasma glucose ≥ 200 mg/dL, HbA1c ≥ 7.0%, or new DM prescription (index date). We used incidence density sampling to match 10 controls per case on the date of follow-up glucose test (to reduce detection bias), in addition to age and date of cohort entry. Exposure to antihypertensive class was assessed during the 30 days prior to index date. Our cohort contained 134 967 patients and had 412 604 glucose tests eligible for matching. A total of 9097 DM cases were matched to 90 495 controls (median age 51 years). Exposure to TD (OR 1.54, 95% CI 1.41 to 1.68) or BB (OR 1.19, 95% CI 1.11 to 1.28) was associated with an increased DM risk, while CCB and RASB exposure was not. TD+BB combination resulted in the fully combined diabetogenic risk of both agents (OR 1.99, 95% CI 1.80 to 2.20; interaction OR 1.09, 95% CI 0.97 to 1.22). In contrast, combination of RASB with either TD or BB showed significant negative interactions, resulting in a smaller DM risk than TD or BB monotherapy.

CONCLUSIONS

Diabetogenic potential of combination therapy should be considered when prescribing antihypertensive therapy.

A retrospective longitudinal cohort study of antihypertensive drug use and new-onset diabetes in Taiwanese patients

Antihypertensive drugs have been linked to new-onset diabetes (NOD); however, data on the effect of these drugs on the development of NOD in hypertensive patients has not been well determined in a clinical setting. The aim was to investigate the association between antihypertensive drugs and NOD in Taiwan. We conducted a retrospective study of hypertensive Taiwanese patients receiving antihypertensive drugs treatment between January 2006 and December 2011. Clinical information and laboratory parameters were collected by reviewing the medical records. We estimated the odds ratios (ORs) of NOD associated with antihypertensive drug use; nondiabetic subjects served as the reference group. A total of 120 NOD cases were identified in 1001 hypertensive patients during the study period. The risk of NOD after adjusting sex, age, baseline characteristics, and lipid profiles was higher among users of thiazide diuretics (OR, 1.65; 95% confidence interval (CI), 1.12–2.45) and nondihydropyridine (non-DHP) calcium channel blockers (CCBs) (OR, 1.96; 95% CI, 1.01–3.75) than among nonusers. Other antihypertensive drug classes were not associated with risk of NOD. Our results show that patients with hypertension who take thiazide diuretics and non-DHP CCBs are at higher risk of developing NOD than those who take other classes of antihypertensive drugs in Taiwan.