Outcomes associated with once-daily versus multiple-daily dosing of buprenorphine/naloxone for opioid use disorder.

BACKGROUND AND OBJECTIVES: Clinical studies examining once-daily versus multiple-daily dosing of buprenorphine/naloxone in patients with opioid use disorder (OUD) in the absence of comorbid pain are lacking. METHODS: This retrospective chart review aimed to compare 100 patients prescribed single-daily buprenorphine/naloxone (n = 50) to those prescribed multiple-daily buprenorphine/naloxone (n = 50) to elucidate the impact that dosing frequency has on negative urine drug screens (UDS) and the number of relapses in OUD. RESULTS: The once-daily cohort produced 84% negative UDSs compared with 74% in the multiple-daily cohort which was statistically significant (p = .034). There were a total of 43 relapses reported in the once-daily cohort, compared with 141 relapses in the multiple-daily cohort (p < .001). The average number of relapses per patient in the single-daily cohort was 0.68 compared with the multiple-daily cohort average of 2.16 (p < .001). In the once-daily cohort, 14% of patients experienced at least one relapse throughout the study, compared with 31% in the multiple-daily cohort (p < .002). There were no significant differences between time to relapse, adherence to treatment, or treatment retention. Statistically significantly more patients in the multiple-daily cohort were using methamphetamines (p = .005); there were no significant differences between groups with the use of any other illicit or non-prescribed substances. DISCUSSION AND CONCLUSIONS: Once-daily dosing was associated with more negative UDSs and fewer opioid relapses compared with multiple-daily dosing. SCIENTIFIC SIGNIFICANCE: This was the first study to evaluate buprenorphine/naloxone dosing frequency for opioid use disorder, in the absence of chronic pain. Additional studies evaluating optimal dosing schedules for relapse prevention are warranted.

Frailty Trends in an Older Veteran Subpopulation 1 Year Prior and Into the COVID-19 Pandemic Using CAN Scores.

Background: We studied the effects of the first year of the COVID-19 pandemic on frailty trends in a subset of older veterans at the Phoenix Veterans Affairs Health Care System. Methods: We identified 3538 and 6103 veterans aged 70 to 75 years as of February 8, 2019, with a calculated Care Assessment Need (CAN) score of ≥ 75 for 1-year mortality and hospitalization, respectively. After excluding veterans with insufficient 2020 and 2021 data, we compared the difference in 1-year mortality and hospitalization CAN scores from 2019 to 2020 with 2020 to 2021 using a paired t test. Results: The difference in mean (SD) 1-year mortality CAN scores from 2020 to 2021 was 0.2 (13.4) when compared with the previous year's -4.9 (12.5) (P < .0001), indicating increased frailty. The difference in 1-year hospitalization CAN scores from 2020 to 2021 was -1.5 (12.0) when compared with the previous year's -2.8 (9.9) (P < .0001). Conclusions: Frailty in our veteran subpopulation as calculated by 1-year mortality CAN scores increased in the first year of the COVID-19 pandemic when compared with a recovering trend the previous year.

Implementation of early follow-up care after heart failure hospitalization.

OBJECTIVES: The evidence supporting early postdischarge hospital follow-up is limited. We implemented a new, multidisciplinary, multistrategy heart failure (HF) team approach that included new clinic slots, predischarge nurse visit, providing a blood pressure cuff and scale, and cardiologist supervision. STUDY DESIGN: Pre- vs postintervention evaluation of outcomes in patients hospitalized with HF between September 1, 2010, and May 30, 2013. We utilized the RE-AIM (reach, effectiveness, adoption, implementation, maintenance) framework to evaluate the intervention. METHODS: For the quantitative evaluation, we compared the proportion of patients in both groups who were scheduled for and completed a cardiology appointment within 7 days after hospitalization ("reach"). We created a Cox model to evaluate the "effectiveness" of the intervention period on a 30-day composite outcome (all-cause emergency department [ED] visit, all-cause hospitalization, or death). In qualitative evaluation, we describe the adoption, implementation, and maintenance of the intervention. RESULTS: Data for 261 patients were analyzed (preintervention, n = 142; post intervention, n = 119). The postintervention period was associated with a higher proportion of patients who were referred to (40% vs 12%; P < .001) and completed (24% vs 10%; P = .003) cardiology follow-up within 7 days of hospital discharge (reach) compared with the preintervention period. After adjustment, the postintervention period was associated with a reduced hazard of the 30-day composite end point (HR, 0.59; 95% CI, 0.37-0.96; P = .04) (effectiveness). CONCLUSIONS: The intervention succeeded in increasing referral to and completion of cardiology appointments within 7 days of discharge. In adjusted analysis, the intervention was associated with lower risk of 30-day all-cause ED visits, all-cause hospitalizations, or death.

Low TSH Is Associated With Frailty in an Older Veteran Population Independent of Other Thyroid Function Tests.

Low TSH is associated with frailty in the older adult. We studied whether low TSH is an independent marker of frailty or is an indicator of subclinical hyperthyroidism, which in turn predicts frailty. Of outpatient veterans seen between January 2005 and December 2016, we identified 100 patients aged ≥60 years with two low TSH (<0.5 µIU/ml) and one fT3 measurement and 50 matched controls (TSH 0.5-5.0 µIU/ml). We used a deficit accumulation approach to create a frailty index (FI). The higher the FI, the more likely (p<0.001) that patients had expired. Patients with low (0.31 ± 0.11 µIU/mL) versus normal (1.84 ± 0.84 µIU/mL) TSH had higher mean FI compared to controls (0.25 ± 0.12 vs. 0.15 ± 0.07, p < .001). Low TSH was significantly associated with frailty (p < .001), independent of age. However, lower TSH was not associated with higher fT3 or fT4 levels. There was a nonsignificant inverse association of fT3 levels with FI (p = .13), which disappeared when adjusted for age. Similar to prior studies, low TSH was associated with frailty. However, neither fT3 nor fT4 predicted low TSH or FI, suggesting that the association of low TSH with frailty is not due to subclinical hyperthyroidism, but perhaps to effects of comorbidities on TSH secretion.

Implementation of low-dose CT screening in two different health care systems: Mount Sinai Healthcare System and Phoenix VA Health Care System.

Implementation of lung screening (LS) programs is challenging even among health care organizations that have the motivation, the resources, and more importantly, the goal of providing for life-saving early detection, diagnosis, and treatment of lung cancer. We provide a case study of LS implementation in different healthcare systems, at the Mount Sinai Healthcare System (MSHS) in New York City, and at the Phoenix Veterans Affairs Health Care System (PVAHCS) in Phoenix, Arizona. This will illustrate the commonalities and differences of the LS implementation process in two very different health care systems in very different parts of the United States. Underlying the successful implementation of these LS programs was the use of a comprehensive management system, the Early Lung Cancer Action Program (ELCAP) Management SystemTM. The collaboration between MSHS and PVAHCS over the past decade led to the ELCAP Management SystemTM being gifted by the Early Diagnosis and Treatment Research Foundation to the PVAHCS, to develop a "VA-ELCAP" version. While there remain challenges and opportunities to continue improving LS and its implementation, there is an increasing realization that most patients who are diagnosed with lung cancer as a result of annual LS can be cured, and that of all the possible risks associated with LS, the greater risk of all is for heavy cigarette smokers not to be screened. We identified 10 critical components in implementing a LS program. We provided the details of each of these components for the two healthcare systems. Most importantly, is that continual re-evaluation of the screening program is needed based on the ongoing quality assurance program and database of the actual screenings. At minimum, there should be an annual review and updating. As early diagnosis of lung cancer must be followed by optimal treatment to be effective, treatment advances for small, early lung cancers diagnosed as a result of screening also need to be assessed and incorporated into the entire screening and treatment program.

Retinoblastoma protein co-purifies with proteasomal insulin-degrading enzyme: implications for cell proliferation control.

Previous investigations on proteasomal preparations containing insulin-degrading enzyme (IDE; EC 3.4.24.56) have invariably yielded a co-purifying protein with a molecular weight of about 110kDa. We have now found both in MCF-7 breast cancer and HepG2 hepatoma cells that this associated molecule is the retinoblastoma tumor suppressor protein (RB). Interestingly, the amount of RB in this protein complex seemed to be lower in HepG2 vs. MCF-7 cells, indicating a higher (cytoplasmic) protein turnover in the former vs. the latter cells. Moreover, immunofluorescence showed increased nuclear localization of RB in HepG2 vs. MCF-7 cells. Beyond these subtle differences between these distinct tumor cell types, our present study more generally suggests an interplay between RB and IDE within the proteasome that may have important growth-regulatory consequences.

Insulin metabolism in human adipocytes from subcutaneous and visceral depots.

Subjects with the metabolic syndrome (insulin resistance, glucose intolerance, dyslipidemia, hypertension, etc.) have a relative increase in abdominal fat tissue compared to normal individuals and obesity has also been shown to be associated with a decrease in insulin clearance. The majority of the clearance of insulin is due to the action of insulin-degrading enzyme (IDE) and IDE is present throughout all tissues. Since abdominal fat is increased in obesity we hypothesized that IDE may be altered in the different fat depots. Adipocytes were isolated from fat samples obtained from subjects during elective abdominal surgery. Fat samples were taken from subcutaneous (SQ) and visceral (VIS) sites. Insulin metabolism was compared in adipocytes isolated from SQ and VIS fat tissue. Adipocytes from the VIS site degraded more insulin that those from SQ fat tissue. Inhibitors of cathepsins B and D has no effect on the degradation of insulin, while bacitracin, an inhibitor of IDE, inhibited degradation by approx. 33% in both SQ and VIS adipocytes. These data show that insulin metabolism is relatively greater in VIS than in SQ fat tissue and potentially due to IDE.

Regulation of protein degradation by insulin-degrading enzyme: analysis by small interfering RNA-mediated gene silencing.

Proteins are vital to the overall structure of cells and to the function of cells in the form of enzymes. Thus the control of protein metabolism is among the most important aspects of cellular metabolism. Insulin's major effect on protein metabolism in the adult animal is inhibition of protein degradation. This is via inhibition of proteasome activity via an interaction with insulin-degrading enzyme (IDE). IDE is responsible for the majority of cellular insulin degradation. We hypothesized that a reduction in IDE would reduce insulin degradation and insulin's ability to inhibit protein degradation. HepG2 cells were transfected with siRNA against human IDE and insulin degradation and protein degradation measured. Both IDE mRNA and protein were reduced by >50% in the IDE siRNA transfected cells. Insulin degradation was reduced by approximately 50%. Cells were labeled with [3H]-leucine to investigate protein degradation. Short-lived protein degradation was unchanged in the cells with reduced IDE expression. Long-lived and very-long-lived protein degradation was reduced in the cells with reduced IDE expression (14.0+/-0.16 vs. 12.5+/-0.07%/4h (long-lived), 9.6+/-2.2% vs. 7.3+/-0.2%/3h (very-long-lived), control vs. IDE transfected, respectively, P<0.005). The inhibition of protein degradation by insulin was reduced 37-76% by a decreased expression of IDE in HepG2 cells. This shows that IDE is involved in cellular insulin metabolism and provides further evidence that insulin inhibits protein degradation via an interaction with IDE.

Insulin-degrading activity in wound fluid.

Patients with diabetes are at great risk of developing lower extremity ulcers. The management of diabetic foot ulcers typically includes early recognition and appropriate clinical care. Recent advances in wound treatment include topical growth factor therapy, which has been successful in diabetic wounds. Growth factors are decreased in wound fluid; this may be due to decreased supply, increased binding, or increased degradation of the naturally occurring growth factors. This study investigates the activity of the insulin-degrading enzyme in wound fluid. Wound fluid was obtained from patients with (n = 17) and without (n = 4) diabetes. Insulin degradation was assayed by incubating [(125)I]insulin with wound fluid and precipitation in trichloroacetic acid. Fluid from nondiabetics degraded 2.22 +/- 0.73%, whereas diabetic fluid degraded significantly more (6.13 +/- 1.48%; P < 0.05). In patients with diabetes, the degradation of insulin by wound fluid correlated with glucose control (hemoglobin A(1c); r(2) = 0.5353; P < 0.001), and patients with worse outcomes (i.e. amputation) had higher wound fluid insulin degradation. The biochemical characteristics of insulin degradation in the wound fluid were consistent with the characteristics of insulin-degrading enzyme. These data suggest that glucose control is a critical factor in wound healing, but a reduction in the insulin-degrading activity in the wound fluid is also a potential therapeutic target.

Reduced action of insulin glargine on protein and lipid metabolism: possible relationship to cellular hormone metabolism.

Insulin analogues are used in the treatment of diabetes to mimic physiological insulin secretion. Glargine is used to provide basal insulin levels. Previous work has shown no differences in glucose uptake when glargine was compared to native insulin. The action of insulin on protein and lipid metabolism is studied infrequently, but these important actions should be considered with insulin analogues. In HepG2 cells, protein degradation was inhibited significantly less by glargine (15% over 3 hours) than by insulin (approximately 20% over 3 hours) (P < .05). Lipid metabolism was investigated in 3T3-L1 cells. In these cells glucose oxidation to CO2 was effected equally, but glargine was less potent than insulin at inhibiting epinephrine-stimulated lipolysis (EC50 = 1.4 v 0.35 nmol/L, P < .001) and at stimulating lipogenesis (EC50 = 1.27 v 8.06 nmol/L, P < .01). Since the action of insulin on protein and lipid metabolism has been suggested to be due to the metabolism of the hormone, we compared the cellular handling of 125I[A14]-glargine to 125I[A14]-insulin in HepG2 cells. While binding of glargine to the insulin receptor was identical to insulin, degradation of glargine was reduced compared to insulin (16.3% +/- 0.3% v 21.6% +/- 0.4% degraded/h, P < .01). Less degraded glargine than insulin was released from cells previously loaded with radiolabeled material (50.1% +/- 2.4% v 58.3% +/- 1.4%/2 h, P < .02). The amount of intact glargine released was concomitantly increased compared to insulin (44.8% +/- 2.6% v 35.8% +/- 1.4%/2 h, P < .02). These data provide further evidence for a relationship between insulin metabolism and insulin action on protein and lipid metabolism; however, the clinical relevance of these differences is hard to realize, since for the most part glargine, used as a basal insulin, is administered in addition to other shorter-acting insulin or analogues, and their effects will mask or reduce glargine effects on lipolysis and protein degradation. However, these studies do show that properties of insulin other than glucose metabolism and mitogenesis must be considered when studying insulin analogues.

Biologically active insulin-derived peptides.

Insulin has many actions within cells many of which are dependent on the cell type. For example, insulin stimulates glucose uptake in adipose tissue and skeletal muscle but not in liver. In liver glucose influx will increase as insulin stimulates the phosphorylation of glucose and eventual storage in the form of glycogen. Insulin also increases glucose oxidation, decreases glucose production, decreases lipolysis, increases protein synthesis and inhibits protein degradation in addition to others. Many actions have been related to insulin binding to its receptor and subsequent phosphorylation cascades, but insulin action on protein degradation has been shown to be linked to insulin degradation, specifically insulin degradation by the insulin-degrading enzyme (IDE). This activity has been shown to be due to an interaction of IDE with the proteasome, which is responsible for degradation of ubiquitin-tagged proteins. Smaller fragments of insulin that are produced by the action of IDE that do not bind to the insulin receptor show a small effect on protein degradation and a modest effect on mitogenesis. These small fragments do however inhibit lipolysis in a similar manner to insulin. If fragments are larger and can bind to the receptor they have been shown to increase glucose oxidation. Studies show that fragments of the insulin molecule have cellular activity, and that the varied actions of insulin are not completely controlled by insulin binding to the insulin receptor, even though the mechanisms may not be mutually exclusive.

Akt promotes increased mammalian cell size by stimulating protein synthesis and inhibiting protein degradation.

Expression of constitutively active Akt3 was found to increase the size of MCF-7 cells approximately twofold both in vitro and in vivo. A regulatable version of Akt1 (MER-Akt) was also found capable of inducing a twofold increase in the size of H4IIE rat hepatoma cells. Rapamycin, a specific inhibitor of mTOR function, was found to inhibit the Akt-induced increase in cell size by 70%, presumably via inhibition of the Akt-induced increase in protein synthesis. To determine whether Akt could be inhibiting protein degradation, thereby contributing to its ability to induce an increase in cell size, we conducted protein degradation experiments in the H4IIE cell line. Activation of MER-Akt was found to inhibit protein degradation to a degree comparable to insulin treatment. The effects of these two agents on protein degradation were not additive, thereby suggesting that they were acting on a similar pathway. An inhibitor of the phosphatidylinositol 3-kinase pathway, LY-294002, blocked both insulin- and Akt-induced inhibition of protein degradation, again consistent with the hypothesis that both agents were acting on the same pathway. In contrast, rapamycin did not block the ability of either agent to inhibit protein degradation. These results indicate that Akt increases cell size through both mTOR-dependent and -independent pathways and that the latter involves inhibition of protein degradation. These studies are also consistent with the hypothesis that insulin's ability to regulate protein degradation is to a large extent mediated via Akt.

Biological activity of a fragment of insulin.

Insulin controls or alters glucose, protein, and fat metabolism as well as other cellular functions. Insulin binds to a specific receptor on the cell membrane initiating a protein phosphorylation cascade that controls glucose uptake and metabolism and long-term effects such as mitogenesis. This process also initiates insulin uptake and ultimate cellular metabolism in all insulin sensitive cells. The effects of insulin on other cellular metabolic properties have not been clearly related to this mechanism. Here we show that intracellular metabolism of insulin may be related to some aspects of insulin actions, specifically control of fat metabolism. A normal intracellular degradation product of insulin has been synthesized and tested for actions on fat turnover in cultured adipocytes. This 7-peptide, B-chain fragment (HLVEALY) inhibits both basal and stimulated lipolysis as measured by glycerol release, but does not inhibit FFA release because of a lack of effect on FFA reesterification in the adipocyte. HLVEALY also enhances insulin's effects on lipogenesis. This study shows that a fragment of insulin produced by the action of the insulin-degrading enzyme has both independent biological effects and interactions with insulin. This supports a biologically important effect of insulin metabolism and insulin degradation products on insulin action on non-glucose pathways.

Control of proteolysis: hormones, nutrients, and the changing role of the proteasome.

PURPOSE OF REVIEW: The maintenance of protein balance is essential for the proper functioning of a cell. Protein degradation must be controlled to account for the availability of nutrients and hormone signals from the body as a whole. The proteasome is the major cytosolic protein degrading machinery, and is responsible for a considerable proportion of cellular protein degradation. It is thus a prime site for the integration of these various signals. We will examine some recent data regarding the mechanisms for control of the peptidolytic activities of the proteasome, and possible implications for signal transduction and integration. RECENT FINDINGS: Nutrients, such as amino acids and fatty acids, have been shown to have effects on proteasome-mediated protein degradation. The ubiquitinylating process is important for the control of protein degradation by the 26S proteasome. Amino acids and hormones control the expression of the necessary components, and can control protein degradation on a relatively longer-term basis. The 20S proteasome has been shown to be capable of degrading proteins without activating subunits. Furthermore, the 20S proteasome is allosterically affected by a number of smaller peptides, suggesting a more immediate mechanism for control. Amino acids and fatty acids have been shown to exert such control in vitro. SUMMARY: As more is learned about the functioning of the proteasome, the greater appreciation we have of its vital role in the control of cellular metabolism. Recent evidence shows that the proteasome is central to the integration of various nutrient and hormonal signals that the cell receives that may impact on protein metabolism.