Effect of low-protein diet on anthracycline pharmacokinetics and cardiotoxicity

Implications of chronic moderate protein-deficiency malnutrition on doxorubicin pharmacokinetics and cardiotoxicity in early post-weaning stage

BACKGROUND

Malnutrition is a common problem in developing countries, and the impact of severe malnutrition on optimal treatment outcomes of chemotherapy in pediatric cancer patients is well documented. However, despite being a more prevalent and distinct entity, moderate malnutrition is until now unexplored for its effects on treatment outcomes.

AIMS

In this study we aimed to investigate the molecular basis of altered pharmacokinetics and cardiotoxicity of doxorubicin observed in early-life chronic moderate protein deficiency malnutrition.

MATERIALS AND METHODS

We developed an animal model of early-life moderate protein-deficiency malnutrition and validated it using clinical samples. This model was used to study pharmacokinetic and toxicity changes and was further utilized to study the molecular changes in liver and heart to get mechanistic insights.

KEY FINDINGS

Here we show that moderate protein-deficiency malnutrition in weanling rats causes changes in drug disposition in the liver by modification of hepatic ABCC3 and MRP2 transporters through the TNFα signalling axis. Furthermore, malnourished rats in repeat-dose doxorubicin toxicity study showed higher toxicity and mortality. A higher accumulation of doxorubicin in the heart was observed which was associated with alterations in cardiac metabolic pathways and increased cardiotoxicity.

SIGNIFICANCE

Our findings indicate that moderate malnutrition causes increased susceptibility towards toxic side effects of chemotherapy. These results may necessitate further investigations and new guidelines on the dosing of chemotherapy in moderately malnourished pediatric cancer patients.

The relationship between body composition and left ventricular performance in women with breast, lymphoma, or sarcoma cancer

BACKGROUND

To understand how body composition in those with elevated body mass index impacts left ventricular function decline during cancer treatment, we determined the association between baseline body mass index (BMI), intra-abdominal adipose tissue (IAT) and subcutaneous adipose tissue (SAT) with baseline to 3-month left ventricular ejection fraction (LVEF) change among women receiving potentially cardiotoxic chemotherapy for breast cancer, lymphoma, or sarcoma.

METHODS

Women underwent potentially cardiotoxic chemotherapy, such as doxorubicin, cyclophosphamide, paclitaxel, and trastuzumab, for treatment of breast cancer, lymphoma, or sarcoma. We obtained magnetic resonance images (MRIs) of body composition and cardiac function prior to treatment, and then a repeat MRI for cardiac function assessment at three months into treatment. Analyses and assessment of abdominal adipose tissue volumes and LVEF outcomes were conducted by independent reviewers blinded to all patient identifiers. A general linear model was created to examine associations between adipose tissue depots, BMI, and 3-month LVEF change.

RESULTS

Women (n = 210) aged 56 ± 11 years with breast cancer, lymphoma, and sarcoma were enrolled (n = 195, 14, 1 respectively). Baseline BMI, IAT, and SAT fat were independently associated with 3-month LVEF declines (p = 0.001 to 0.025 for all). After adjusting for baseline cardiovascular disease risk factors, BMI, IAT, and SAT, BMI remained the only variable associated with 3-month LVEF decline (p = 0.047).

CONCLUSIONS

These results suggest that factors other than abdominal adipose tissue or traditional cardiovascular risk factors may contribute to 3-month declines in LVEF among women with elevated BMI receiving potentially cardiotoxic chemotherapy. Further investigation should be conducted on psychosocial stress, physical activity, sleep, or diet.

TRIAL REGISTRATION

DETECTIV_NCT01719562, WF99112, & WF97415-NCT02791581.

Impact of protein deficient diet on the pharmacokinetics of glibenclamide in a model of malnutrition in rats

Purpose

The present investigation deals with the impact of protein energy malnourished condition on the pharmacokinetic profile of glibenclamide. Protein energy malnourished condition leads to malnutrition related diabetes mellitus (MRDM), Fibrocalculus pancreatic diabetes mellitus (FCPD) or Lean body mass diabetes mellitus (LBMDM).

Method

In the present study, malnutrition was developed in female wistar rats using a modified protein deficient diet (0.5%). The experiment was performed on 12 animals, each group containing 6 female wistar rats. The control group animals were fed with standard pellet diet (AIN 93 G diet) while group 2 received the low protein diet (0.5%) for 75 days. Glibenclamide (Gli) suspension (30 mg/kg) was administered orally to these rats on 75 days and kinetic parameters were evaluated by HPLC analysis.The pharmacokinetic interpretation done by pksolver software version 2.0, statistical comparison done by applying student T test.

Results

The results of body weight and hematological parameters indicated a significant decreased in the body weight in protein deficit rats to 124.1 ± 6.2 g compared to 235.5 ± 8.4 g (p < 0.01) control rats; whereas a decrease in the hemoglobin to 5.8 ± 0.6 g/dL, total blood protein level to 6.9 ± 0.6 g/dL and blood albumin levels to 2.7 ± 0.4 g/dL in protein deficit rats compared to 15 ± 0.7 g/dL(p < 0.05), 8.1 ± 0.4 g/dL(p < 0.05), and 4.5 ± 0.2 g/dL(p < 0.05), respectively in control rats. All these findings reflect the malnourished condition and weight loss due to a protein deficit diet in experimental animals. There was an increase in the fasting blood glucose levels up to 150 ± 17.4 mg/dL in the protein deficit diet group as compared to 98.7 ± 14.1 mg/dL(p < 0.05) in control rats reflect the prediabetes state in malnourished animals. The results of the pharmacokinetic study reflect a significant lowering of half-life (T½) of glibenclamide to 96.8 ± 0.8 min. in malnourished rats compared to 166.7 ± 0.74 min. (p < 0.001) in control rats. The maximum concentration (Cmax) of glibenclamide in the malnourished rats was significantly higher 20.74 ± 0.65 μg/mL and also took double time i.e. about 180 min. to reach maximum concentration (Tmax) compared to the control rats values 7.9 ± 0.84 μg/mL (p < 0.001) and 90.0 ± 0.24 min. (p < 0.001) respectively. The area under the plasma concentration-time curve [AUC(0-∞)] in malnourished rats increased 4439.1 ± 40.6 μg/ml*min as compared to 1235.9 ± 55.8 μg/ml*min (p < 0.001) in control rats. There was a lowering in the total body clearance (CL) to 0.4 ± 0.02 L/hr and volume of distribution (Vd) to 1.75 ± 0.07 L of glibenclamide in the protein deficit group compared to 1.4 ± 0.3 L/hr (p < 0.001) and 3.14 ± 0.8 L (p < 0.01), respectively in the control rats.

Conclusion

From this study it concludes that there is an increase in the T½, Cmax, Tmax and AUC(0-∞) of glibenclamide in malnourished rats while the total body clearance and volume of distribution is lowered. Therefore this study proposes to conduct an adequate pharmacokinetic study in malnourished patients to decide whether the standard glibenclamide dose should be adapted according to the nutritional status of the individual.

Pharmacokinetics of cancer therapeutics and energy balance: the role of diet intake, energy expenditure, and body composition

Energy balance accounts for an individual's energy intake, expenditure, and storage. Each aspect of energy balance has implications for the pharmacokinetics of cancer treatments and may impact an individual's drug exposure and subsequently its tolerance and efficacy. However, the integrated effects of diet, physical activity, and body composition on drug absorption, metabolism, distribution, and excretion are not yet fully understood. This review examines the existing literature on energy balance, specifically the role of dietary intake and nutritional status, physical activity and energy expenditure, and body composition on the pharmacokinetics of cancer therapeutics. As energy balance and pharmacokinetic factors can be influenced by age-related states of metabolism and comorbidities, this review also explores the age-related impact of body composition and physiologic changes on pharmacokinetics among pediatric and older adult populations with cancer.

Nutritional interventions based on dietary restriction and nutrient reductions for the prevention of doxorubicin chemotherapy side effects

BACKGROUND: Doxorubicin (DOX) is one of most used chemotherapeutic drugs, but it has important adverse effects. Nutrition has a critical role to prevent or minimize chemotherapy side effects. Caloric and nutrient restriction has been widely studied in different health fields showing extensive beneficial effects. Given the importance of these interventions, it is expected that some of them have benefits in patients under DOX chemotherapy. OBJECTIVE: This review aimed to compile published studies evaluating the effects of different dietary intetrventions based on restriction of calories or certain nutrients against DOX-induced damage and toxicity. RESULTS: Caloric restriction and partial reduction of fat have shown to reduce DOX cardiotoxicity correlating with a reduction of oxidative stress. Reduction of dietary fat was proved to act in the same sense at liver and kidney. Studies in relation to protein reduction is more elevated has focused only on kidneys and bone, and under certain circumstances, these interventions could increase susceptibility to DOX toxicity. CONCLUSIONS: The promising effects of restriction of dietary fat, protein and sodium on differerent organs have been supported by a greater number of studies among all the dietary interventions evaluated. Still, clinical studies are necessary to confirm the potential usefulness of these interventions.

Anthracycline-related cardiotoxicity in older patients with acute myeloid leukemia: a Young SIOG review paper

The incidence of acute myeloid leukemia (AML) increases with age. Intensive induction chemotherapy containing cytarabine and an anthracycline has been part of the upfront and salvage treatment of AML for decades. Anthracyclines are associated with a significant risk of cardiotoxicity (especially anthracycline-related left ventricular dysfunction [ARLVD]). In the older adult population, the higher prevalence of cardiac comorbidities and risk factors may further increase the risk of ARLVD. In this article of the Young International Society of Geriatric Oncology group, we review the prevalence of ARLVD in patients with AML and factors predisposing to ARLVD, focusing on older adults when possible. In addition, we review the assessment of cardiac function and management of ARLVD during and after treatment. It is worth noting that only a minority of clinical trials focus on alternative treatment strategies in patients with mildly declined left ventricular ejection fraction or at a high risk for ARLVD. The limited evidence for preventive strategies to ameliorate ARLVD and alternative strategies to anthracycline use in the setting of cardiac comorbidities are discussed. Based on extrapolation of findings from younger adults and nonrandomized trials, we recommend a comprehensive baseline evaluation of cardiac function by imaging, cardiac risk factors, and symptoms to risk stratify for ARLVD. Anthracyclines remain an appropriate choice for induction although careful risk-stratification based on cardiac disease, risk factors, and predicted chemotherapy-response are warranted. In case of declined left ventricular ejection fraction, alternative strategies should be considered.

Ultra-High-Precision, in-vivo Pharmacokinetic Measurements Highlight the Need for and a Route Toward More Highly Personalized Medicine

Clinical drug dosing would, ideally, be informed by high-precision, patient-specific data on drug metabolism. The direct determination of patient-specific drug pharmacokinetics ("peaks and troughs"), however, currently relies on cumbersome, laboratory-based approaches that require hours to days to return pharmacokinetic estimates based on only one or two plasma drug measurements. In response clinicians often base dosing on age, body mass, pharmacogenetic markers, or other indirect estimators of pharmacokinetics despite the relatively low accuracy of these approaches. Here, in contrast, we explore the use of indwelling electrochemical aptamer-based (E-AB) sensors as a means of measuring pharmacokinetics rapidly and with high precision using a rat animal model. Specifically, measuring the disposition kinetics of the drug tobramycin in Sprague-Dawley rats we demonstrate the seconds resolved, real-time measurement of plasma drug levels accompanied by measurement validation via HPLC-MS on ex vivo samples. The resultant data illustrate the significant pharmacokinetic variability of this drug even when dosing is adjusted using body weight or body surface area, two widely used pharmacokinetic predictors for this important class of antibiotics, highlighting the need for improved methods of determining its pharmacokinetics.

Cardiotoxicity of anthracycline therapy: current perspectives

Anthracyclines, especially doxorubicin and daunorubicin, are the drugs of first choice in the treatment of patients with hematologic malignancies, soft-tissue sarcomas, and solid tumors. Unfortunately, the use of anthracyclines is limited by their dose-dependent and cumulative cardiotoxicity. The molecular mechanism responsible for anthracycline-induced cardiotoxicity remains poorly understood, although experimental and clinical studies have shown that oxidative stress plays the main role. Hence, antioxidant agents, especially dexrazoxane, and also other drug classes (statins, β-blockers) proved to have a beneficial effect in protecting against anthracycline-induced cardiotoxicity. According to previous clinical trials, the major high-risk factors for anthracycline-induced cardiotoxicity are age, body weight, female gender, radiotherapy, and other diseases such as Down syndrome, familial dilated cardiomyopathy, diabetes and hypertension. Consequently, further studies are needed to elucidate the molecular pathogenesis of anthracycline-induced cardiotoxicity and also to discover new cardioprotective agents against anthracycline-induced cardiotoxicity.

The influence of vitamin B12 supplementation on the level of white blood cells and lymphocytes phenotype in rats fed a low-protein diet

Protein malnutrition has a negative effect on body composition and some blood parameters, especially in the young growing organism. One of nutritional factors which could protect against negative consequences of protein deficiency may be B group vitamins. The aim of the study was to investigate the effect of vitamin B12 supplementation on the immune system in rats fed a standard and a low-protein diet. Rats were fed a control (20% of energy from protein) or a protein-deficient diet (4.5% of energy from protein). Half of animals in each group were additionally supplemented with vitamin B12 (300% of the daily intake). The white blood cells analysis and lymphocytes immunophenotyping (number and percentage) were performed. Low-protein diets caused disturbances in WBC and lymphocyte subpopulations in both short- (30-day) as well as long-term periods (90-day). Vitamin B12 supplementation significantly reduced the negative impact of protein malnutrition after 30 days, however had no effect on long-term malnutrition. Furthermore, vitamin B12 addition in rats fed a control diet did not affect the studied parameters. This observation opens the promise of use of vitamin B12 supplementation to improve immune system parameters in protein malnourished organisms.