The role of basal insulins in the treatment of people with type 2 diabetes and chronic kidney disease: A narrative review

The majority of cases of chronic kidney disease (CKD) worldwide are driven by the presence of type 2 diabetes (T2D), resulting in an increase in CKD rates over the past few decades. The existence of CKD alongside diabetes is associated with increased burden of cardiovascular disease and increased risk of death. Optimal glycaemic control is essential to prevent progression of CKD, but achieving glycaemic targets in people with CKD and diabetes can be challenging because of increased risk of hypoglycaemia and limitations on glucose-lowering therapeutic options. This review considers the challenges in management of T2D in people with impaired kidney function and assesses evidence for use of basal insulin analogues in people with CKD.

Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

The Effects of Adjuvant Chemoradiotherapy (CRT) on Myeloid-Derived Suppressor Cell (MDSC) Subsets in Glioblastoma (GBM)

PURPOSE/OBJECTIVE(S)

GBM continues to be a diagnosis with an exceedingly low survival rate despite standard therapy of resection followed by concurrent CRT. MDSC, immunosuppressive myeloid cells that aid immune system evasion by the tumor, expand during fractionated RT. To date, little is known about the effects of CRT on MDSC subsets. The goal of our pilot study is to compare peripheral blood MDSC subset frequency in patients (pts) undergoing CRT. We hypothesize that the pro-tumor, monocytic MDSC (M-MDSC) subset increases following CRT.

MATERIALS/METHODS

Pts over the age of 18 yo with a new diagnosis of GBM from a single institution participated in the study between 7/2022 -1/2023. Exclusion criteria included prior history of brain RT. Baseline peripheral blood samples were collected within one week prior to CRT start and post-CRT samples were collected within the last week of CRT. Peripheral blood mononuclear cells (PBMC) were isolated from whole blood and freshly stained for intracellular flow cytometric analyses. Total MDSC (singlet, viable, non-lymphocyte, CD11b+CD33+ HLA-DR- cells) and subsets (M-MDSC, granulocytic (G-MDSC), and early MDSC (eMDSC)) were identified. Percent frequency (%fx) of total and MDSC subsets as well as MDSC activation status (n = 3) (interleukin (IL)-10, transforming growth factor-β (TGF-β), interferon gamma (IFNγ)) was compared before and after CRT.

RESULTS

The average age of pts receiving CRT (n = 4) was 70 yo. Fractionated RT consisted of CF RT (n = 2), 6000 cGy in 30 fractions, and HF RT (n = 2), 4005 cGy in 15 fractions. All pts received concurrent chemotherapy with temozolomide. The %fx of MDSC of non-lymphocytes started at 29.2% prior to CRT and decreased to 9.9% at the end of CRT. The fold change of %fx of total MDSC in CF RT and HF RT was 0.39 and 0.29, respectively. The mean change in %fx of MDSC subsets before and after CRT are shown in Table 1. The mean %fx of TGF-β-expressing MDSC in all GBM pts increased by 3.5% after CRT. The mean IFNγ+ MDSC %fx for all GBM pts decreased after CRT from 24.2% to 16.2% with a corresponding decrease in geometric mean fluorescence intensity (GMFI). The mean %fx of IL-10+ MDSC decreased by 1.5% at the end of CRT with a decrease in GMFI from 5550 to 1806.

CONCLUSION

In this limited dataset of pts with GBM receiving standard of care adjuvant therapy, we identified an expansion in the eMDSC and decrease in the M-MDSC subsets. These early results suggest HF RT may promote immunity that is more supportive of anti-tumor function, with a lesser increase in fold change of total MDSC after CRT. A more detailed understanding of the effect of RT on myeloid subpopulations is essential to addressing immune suppression in pts with GBM.

Impact of the Affordable Care Act on Pediatric Proton Radiation Therapy Access

PURPOSE/OBJECTIVE(S)

Previous work has demonstrated that socioeconomic factors affect the use of PT in children1. Medicaid expansion came into effect in 2014. In 2014, there were 15 proton centers in the US, which increased to 31 by 20202. The effects of increased PT center number and expansion of insurance coverage on PT access has yet to be investigated.

MATERIALS/METHODS

This was an observational cohort study using the National Cancer Database (NCDB) to assess for changes in utilization of PT for pediatric cancers before and after Medicaid expansion. Demographics and characteristics were summarized with one-way analysis of variance for continuous variables and χ2 for categorical variables. Data regarding geography of treated patients was suppressed. Logistic regression was performed to investigate the effect of SES and insurance on treatment type. All p values are two-sided, with a significance level of 0.05 used. Statistical analyses were performed in R (version 4.1.2).

RESULTS

There were 17,096 patients diagnosed at ages ≤21 years from 2004-2020 treated with either photon or PT with known insurance status. 14,491 patients were treated with photons; 2,605 patients received PT. The number of uninsured patients dropped after 2014 from 3.5% to 2.0%, p<0.001. The number of patients with Medicaid who received PT increased after 2014 (21.9% to 28.5%, p<0.001). From 2004-2020, PT increased from 0.4% to 12.4%, peaking in 2018 at 13.9%. Patients with private insurance had higher odds (OR1.5, CI 1.28-1.65) of PT compared to those with Medicaid when controlling for the increased likelihood of PT over time. Patients of higher SES had a higher likelihood of getting treated with PT both before and after Medicaid expansion, while those of the lowest quartile SES did not witness a significant change in the proportion of patients being treated with PT, (11.5% to 12.1% after 2014). Utilization based on race did not significantly change after 2014 among White, Black, and Asian/Pacific Islander populations, but did decrease for patients who identified as Spanish/Hispanic origin (16.9% to 15.0%, p<0.001), and American Indians from 0.7 to 1.3% (p<0.001).

CONCLUSION

Despite the benefits of Medicaid expansion from the ACA since 2014, pediatric patients of Black race and Hispanic ethnicity failed to experience improved access to PT. Pediatric patients with private insurance continued to be more likely to receive PT than patients on Medicaid. Investigation by geography, as well as tumor type, is necessary to provide essential data for creating effective policies to increase equitable access to PT.

Effect of External Beam Radiation Therapy (EBRT) and Brachytherapy (BT) on Circulating MDSC Populations in Patients Treated Definitively for Cervical Cancer

PURPOSE/OBJECTIVE(S)

The immunosuppressive function of myeloid derived suppressor cells (MDSCs) has been implicated in the regulation of immune responses against cancer. MDSCs have been associated with progression and poor response to therapy in various types of cancer, including cervical cancer. Radiation treatment (RT) alters immune cell populations within the tumor and is thought to augment antitumor responses. However, whether RT also recruits immunosuppressive MDSC populations is not well understood. Here, we investigate how circulating MDSC populations change in response to RT and if changes in MDSC frequency or subsets is predictive of RT responses in cervical cancer patients.

MATERIALS/METHODS

Newly diagnosed, treatment-naïve pts with locally advanced carcinoma of the cervix will be enrolled from July 2022 to July 2023. EBRT to the pelvis was delivered at a dose of 45 Gy in 25 fractions with a simultaneous integrated boost of 52-55 Gy to involved regional lymph nodes and parametria and concurrent weekly cisplatin. Gross tumor was boosted via interstitial or tandem ring BT (22.5-27.5 Gy) after completion of EBRT. Serial blood samples were collected prior to initiating therapy (T0), post-EBRT and pre-BT (T1), and one-month post-BT (T2). Treatment response was determined based on pre-treatment MRI compared to MRI post-EBRT. Peripheral blood mononuclear cells (PBMCs) were isolated from whole blood using density gradient centrifugation and stained for analysis via flow cytometry. MDSC populations were identified by Live/Dead-CD11b+CD33+HLA-DR- staining. MDSC subsets were further subdivided into granulocytic (G-, CD15+CD14-), monocytic (M-, CD15-CD14+), or early-MDSCs (e-, CD15-CD14-).

RESULTS

Blood samples were collected at indicated time points for four patients (FIGO stage IIA-IIB). Three had partial responses to chemoradiotherapy (CRT), while one had a complete response. All three patients with partial response had an increase in total frequency of circulating MDSCs in response to EBRT/BT (mean %fx MDSC 16.6 at T0 to 35.9 at T2), and an increase in total MDSCs in two of these patients occurred with EBRT alone. Interestingly, the patient that had a complete response had fewer MDSCs at T2 relative to T0 (35.8% at T0 to 27% at T2). Proportion of MDSC subsets varied considerably among the patients, and all had altered distribution of subsets in response to RT. G-MDSCs expanded the most to RT while M-MDSCs and e-MDSCs were less affected (mean fold change from T0 to T2 G-MDSC 4.75, M-MDSC 1.27, e-MDSC 0.942).

CONCLUSION

In this cohort of patients, an increase in MDSC frequency occurred after RT and altered subset distribution. Only the patient with a complete response had fewer total MDSCs following completion of CRT, suggesting further studies are needed to determine if circulating MDSCs could be a biomarker for treatment response to RT in cervical cancer.

A study on pharmacokinetics, pharmacodynamics and safety of lixisenatide in children and adolescents with type 2 diabetes

OBJECTIVE

The aim of this study was to investigate the pharmacokinetic, pharmacodynamic and safety profile of the glucagon-like peptide-1 receptor agonist, lixisenatide, for the treatment of type 2 diabetes (T2D) in pediatric individuals.

MATERIALS AND METHODS

In this Phase 1, multicenter, randomized, double-blind, placebo-controlled, parallel-group, ascending repeated dose study (NCT02803918), participants aged ≥10 and < 18 years were randomized 3:1 to receive once-daily lixisenatide in 2-week increments of 5, 10, and 20 μg (n = 18) or placebo (n = 5) for 6 weeks.

RESULTS

Mean lixisenatide concentrations generally increased with increasing doses irrespective of anti-drug antibody (ADA) status; however, mean lixisenatide concentrations and inter-subject variability were higher for participants with positive ADA status. Improvements in fasting plasma glucose, post-prandial glucose, AUC_0-4.5 , HbA_1c , and body weight were observed with lixisenatide. Overall, the safety profile was consistent with the known profile in adults, with no unexpected side effects and no treatment-emergent adverse events resulting in death or discontinuation. The most common events in the lixisenatide group were vomiting (11.1%) and nausea (11.1%). No symptomatic hypoglycemia was reported in either group. No clinically significant hematologic, biochemical or vital sign abnormalities were observed.

CONCLUSIONS

Mean lixisenatide concentrations generally increased with increasing dose, irrespective of ADA status. Lixisenatide was associated with improved glycemic control and a trend in body weight reduction compared with placebo. The safety and tolerability profile of repeated lixisenatide doses of up to 20 μg per day in children and adolescents with T2D was reflective of the established safety profile of lixisenatide in adults.

Management of Type 2 Diabetes in People With Renal Impairment

Diabetes is a progressive disease associated with micro- and macrovascular complications. Type 2 diabetes (T2D) is the leading contributor to chronic kidney disease (CKD) worldwide, which itself is associated with an increased burden of cardiovascular disease, increased risk of hypoglycemia, and increased risk of death beyond that caused by diabetes alone. In this video series available on The Journal of Family Practice website, the authors discuss how CKD in people with T2D is defined, potential consequences of CKD in this patient population, and how those with CKD and T2D should be identified, monitored, and treated. The authors discuss the best management approaches for CKD in those with T2D, including blood pressure control, renin-angiotensin-aldosterone system blockade, use of sodium-glucose cotransporter-2 inhibitors, and glycemic control. The importance of glycemic control in the prevention and reduction of CKD progression in people with T2D is reviewed, with an emphasis on the use of antihyperglycemic agents as renal function declines. Finally, the authors discuss the use of basal insulin in this patient population, emphasizing the importance of reaching glycemic control goals while minimizing hypoglycemia. They note that, in people with T2D and reduced renal function, second-generation basal insulin analogs have demonstrated comparable efficacy to first-generation basal insulin analogs in reducing HbA1c levels—but with less hypoglycemia.

Hemodialysis: Evidence of Enhanced Molecular Clearance and Ultrafiltration Volume by Using Pulsatile Flow

We describe several in vitro experiments showing evidence that pulsatile flow hemodialysis enhances ultrafiltration volume and molecular clearance as compared with steady flow hemodialysis. A new pulsatile pump and a conventional roller pump were compared using different hollow fiber dialyzers and a simulated blood solution containing urea, aspartame and vitamin B-12 at different flow rates and configurations. Ultrafiltration volume and concentration of urea, aspartame and B-12 were measured and molecular clearance (K) calculated. Ultrafiltration volume markedly increased with pulsatile flow. After 10 min K for urea with pulsatile flow was higher in all experiments even when ultrafiltration was prevented. Clearance of aspartame and B-12 also increased with pulsatile flow. We propose three mechanisms by which pulsatile flow is more efficient than steady flow hemodialysis: greater fluid energy, avoidance of molecular channeling and avoidance of membrane layering. We hypothesize that using pulsatile flow in hemodialysis can significantly shorten the duration of dialysis sessions for most of the patients, and consequently reduce the duration of the procedure and its cost.

Fixed-Dose Combination of Canagliflozin and Metformin for the Treatment of Type 2 Diabetes: An Overview

Metformin is recommended as a first-line therapy for patients with type 2 diabetes mellitus (T2DM). However, many patients do not achieve glycemic goals with metformin monotherapy and require subsequent combination therapy with other antihyperglycemic agents (AHAs). For newly diagnosed patients with high blood glucose, initial combination therapy may be required to achieve glycemic control. The American Association for Clinical Endocrinologists algorithm for the treatment of T2DM recommends metformin plus a sodium glucose co-transporter 2 (SGLT2) inhibitor as the first oral combination in patients who present with HbA1c ≥7.5%. Canagliflozin, an SGLT2 inhibitor, lowers the renal threshold for glucose and increases urinary glucose excretion leading to a mild osmotic diuresis and a net caloric loss. The effect of canagliflozin is insulin-independent and complementary to other AHAs, including metformin. A fixed-dose combination (FDC) of canagliflozin and metformin is also available with variable dosing, which may be attractive to some patients owing to the potential for reduced pill burden and costs. This article reviews the efficacy and safety of canagliflozin in combination with metformin based on data from the canagliflozin phase 3 clinical program. As initial combination therapy in drug-naïve patients or as dual therapy with metformin or triple therapy in combination with metformin and other AHAs, canagliflozin 100 and 300 mg improved glycemic control and provided reductions in body weight and systolic blood pressure that were sustained for up to 104 weeks. Canagliflozin was generally well tolerated across studies in combination with metformin. An increased incidence of adverse events (AEs) related to the mechanism of SGLT2 inhibition (i.e., genital mycotic infections, urinary tract infections, osmotic diuresis-related AEs) was observed with canagliflozin. Canagliflozin was associated with a low incidence of hypoglycemia when not used in conjunction with AHAs associated with hypoglycemia (i.e., insulin or sulfonylurea). Together, these results support the use of a canagliflozin and metformin FDC as a treatment approach for a broad range of patients with T2DM.

Funding: Janssen Scientific Affairs, LLC.

Long-term efficacy and safety of linagliptin in patients with type 2 diabetes and severe renal impairment: a 1-year, randomized, double-blind, placebo-controlled study

OBJECTIVE

This placebo-controlled study assessed long-term efficacy and safety of the dipeptidyl peptidase-4 inhibitor linagliptin in patients with type 2 diabetes and severe renal impairment (RI).

RESEARCH DESIGN AND METHODS

In this 1-year, double-blind study, 133 patients with type 2 diabetes (HbA(1c) 7.0-10.0%) and severe RI (estimated glomerular filtration rate [eGFR] <30 mL/min/1.73 m(2)) at screening were randomized to linagliptin 5 mg (n = 68) or placebo (n = 65) once daily, added to existing background therapy. The primary efficacy end point was HbA(1c) change from baseline to week 12. Efficacy and safety end points were assessed after 1 year.

RESULTS

At week 12, adjusted mean HbA(1c) decreased by -0.76% with linagliptin and -0.15% with placebo (treatment difference, -0.60%; 95% CI -0.89 to -0.31; P < 0.0001). HbA(1c) improvements were sustained with linagliptin (-0.71%) over placebo (0.01%) at 1 year (treatment difference -0.72%, -1.03 to -0.41; P < 0.0001). Mean insulin doses decreased by -6.2 units with linagliptin and -0.3 units with placebo. Overall adverse event incidence was similar over 1 year (94.1 vs. 92.3%). Incidence of severe hypoglycemia with linagliptin and placebo was comparably low (three patients per group). Linagliptin and placebo had little effect on renal function (median change in eGFR, -0.8 vs. -2.2 mL/min/1.73 m(2)), and no drug-related renal failure occurred.

CONCLUSIONS

In patients with type 2 diabetes and severe RI, linagliptin provided clinically meaningful improvements in glycemic control with very low risk of severe hypoglycemia, stable body weight, and no cases of drug-related renal failure. The potential for linagliptin to spare insulin and provide long-term renal safety warrants further investigations.

Efficacy and safety of sitagliptin in patients with type 2 diabetes and ESRD receiving dialysis: a 54-week randomized trial

BACKGROUND

Treatment with oral antihyperglycemic agents has not been well characterized in patients with type 2 diabetes and end-stage renal disease (ESRD). The efficacy and safety of sitagliptin and glipizide monotherapy in patients with type 2 diabetes and ESRD on dialysis therapy were assessed in this study.

STUDY DESIGN

54-week, randomized, double-blind, parallel-arm study.

SETTING & PARTICIPANTS

From 31 clinical sites in 12 countries, 129 patients 30 years or older with type 2 diabetes and ESRD who were on dialysis therapy and had a hemoglobin A1c (HbA1c) level of 7%-9% were randomly assigned 1:1 to treatment.

INTERVENTION

Monotherapy with sitagliptin, 25 mg daily or glipizide (initiated with 2.5 mg daily and titrated up to a potential maximum dose of 10 mg twice daily or down to avoid hypoglycemia).

OUTCOMES

Primary end points were 54-week change in HbA1c level from baseline and tolerability with sitagliptin. A secondary end point was the comparison of sitagliptin versus glipizide on the incidence of symptomatic hypoglycemia.

RESULTS

Of 129 patients randomly assigned, 64 were in the sitagliptin group (mean baseline age, 61 years; HbA1c, 7.9%) and 65 were in the glipizide group (mean baseline age, 59 years; HbA1c, 7.8%). After 54 weeks, the least squares mean change from baseline in HbA1c level was -0.72% (95% CI, -0.95% to -0.48%) with sitagliptin and -0.87% (95% CI, -1.11% to -0.63%) with glipizide, for a difference of 0.15% (95% CI, -0.18% to 0.49%). The incidences of symptomatic hypoglycemia and severe hypoglycemia were 6.3% versus 10.8% (between-group difference, -4.8% [95% CI, -15.7% to 5.6%]) and 0% versus 7.7% (between-group difference, -7.8% [95% CI, -17.1% to -1.9%]) in the sitagliptin and glipizide groups, respectively. Higher incidences (ie, 95% CI around between-treatment difference excluded 0) of cellulitis and headache were found with sitagliptin compared to glipizide (6.3% vs 0%, respectively, for both).

LIMITATIONS

Small sample size limits between-group comparisons.

CONCLUSIONS

Treatment with sitagliptin or glipizide monotherapy was effective and well tolerated over 54 weeks in patients with type 2 diabetes and ESRD who were receiving dialysis.

The impact of alcohol and alcohol expectancies on male perception of female sexual arousal in a date rape analog

The impact of alcohol and alcohol expectancies on men's perception of female sexual arousal and men's ability to discriminate accurately female sexual intentions in a dating situation was examined. In a 2 (alcohol) x 2 (expectancy) balanced placebo design, men were exposed to an audiotape of a date rape and asked to signal when the man should stop making sexual advances. On 4 occasions during the vignette, participants rated how sexually aroused the woman on the tape was at that moment. Relative to controls, participants who consumed alcohol or expected to consume alcohol took significantly longer to identify the inappropriateness of the man's sexual behavior toward his date. Similarly, alcohol participants also rated the woman's arousal level significantly higher at the first 2 refusals. Implications of the results are discussed.

Trends, rhythms, and aberrations in global climate 65 Ma to present

Since 65 million years ago (Ma), Earth's climate has undergone a significant and complex evolution, the finer details of which are now coming to light through investigations of deep-sea sediment cores. This evolution includes gradual trends of warming and cooling driven by tectonic processes on time scales of 10(5) to 10(7) years, rhythmic or periodic cycles driven by orbital processes with 10(4)- to 10(6)-year cyclicity, and rare rapid aberrant shifts and extreme climate transients with durations of 10(3) to 10(5) years. Here, recent progress in defining the evolution of global climate over the Cenozoic Era is reviewed. We focus primarily on the periodic and anomalous components of variability over the early portion of this era, as constrained by the latest generation of deep-sea isotope records. We also consider how this improved perspective has led to the recognition of previously unforeseen mechanisms for altering climate.

Social workers' knowledge of and experience with sexual exploitation by psychotherapists

A survey of licensed social workers in Texas using self-administered questionnaires revealed that, during the previous 12 months, 17 percent had worked with at least one victim of sexual exploitation by a psychotherapist. Social workers licensed as advanced clinical practitioners, licensed social workers with master's degrees, and those working in private practice were most likely to have worked with a victim of such sexual exploitation. Most respondents were not familiar with the provisions of new Texas legislation concerning sexual exploitation by psychotherapists, including definitions and reporting requirements. The majority indicated they would be interested in additional training.

Does inflammation contribute to the eradication of basal cell carcinoma following curettage and electrodesiccation?

BACKGROUND

Curettage and electrodesiccation (C&D) is probably the technique most frequently utilized by dermatologists to treat basal cell carcinomas (BCC). From histologic studies, it appears C&D does not completely mechanically remove all nests of BCC in a substantial number of cases. Nevertheless, the reported 5-year reoccurrence rate following C&D is significantly less than this histologically observed residual tumor frequency immediately following C&D. Among the multiple possibilities that exist to explain why these residual nests do not appear as recurrent tumor more frequently is the theory that inflammation developing after C&D clears residual tumor.

OBJECTIVE

To test the hypothesis that inflammation developing after C&D clears residual tumor not mechanically removed by the procedure.

METHODS

The frequency of residual BCC detected histologically immediately following C&D was compared with the frequency 1 month after the C&D, an amount of time in which an effect (if any) of inflammation could occur.

RESULTS

Twenty-two of 29 primary BCC < 1 cm treated by C&D were tumor free immediately following the procedure (clearance rate, 75.9%). Eleven of 14 primary BCC < 1 cm treated by C&D then allowed to granulate 1 month before excision and histologic analysis were tumor free, for a clearance rate of 78.6%. Examination of larger tumors immediately following C&D revealed size is a significant variable for clearance rates. Eleven primary BCC > 1 cm but < 2 cm were examined histologically immediately following C&D; only three were tumor free for a clearance rate of 27.3%. Only one of five tumors > 2 cm thus treated was tumor free, for a clearance rate of 20%. Nine recurrent BCC of various sizes were treated by C&D and immediately examined histologically. Two were tumor free for a clearance rate of 22.2%. Two recurrent BCC were allowed to heal 1 month following C&D; one of these was tumor free when excised.

CONCLUSION

For primary BCC < 1 cm, no evidence was found that inflammation occurring over 1 month following C&D clears residual tumor. It was also noted that C&D fails to completely remove tumor in a large majority of primary BCC > 1 cm, and in recurrent BCC.

Evaluation of enzyme-linked immunoassay for serological diagnosis of cysticercosis

We evaluated a commercially available enzyme-linked immunoassay (ELISA) from LMD Laboratories, Inc., Carlsbad, Calif., for the detection of antibodies in serum to the cysticercus of Taenia solium. The ELISA was performed on 308 serum samples; 198 from a pool of healthy individuals, 42 from patients who had antibodies against a variety of parasites other than T. solium, and 68 from patients suspected of having cysticercosis. All of these 68 specimens were tested both by the ELISA and by an immunoblot method (enzyme-linked immunoelectrotransfer blot assay [EITB]) developed at the Parasitic Serology Laboratory of the Centers for Disease Control and Prevention. Twenty-seven of the 68 serum samples from patients suspected of having cysticercosis were positive by both EITB and ELISA, while 31 were negative by both assays. ELISA results for three and two samples were considered false positive and false negative, respectively, when compared with the results of EITB. Results for an additional five samples were considered equivocal but were technically positive because their optical density readings were slightly above the cutoff value. Three of the 198 serum samples from the bank of serum samples from healthy individuals were also false positive by ELISA (the EITB result for the samples was negative). Six other serum samples from healthy individuals which had equivocal results and the five serum samples from patients with equivocal results were EITB negative. Serum samples containing antibodies against Echinococcus spp. frequently cross-reacted with the cysticercus ELISA antigen (13 of 16 specimens), but serum samples with antibodies against other parasites did not (2 of 26 specimens); all of these serum samples were EITB negative. The commercially available ELISA that we describe is a simple and rapid test. Considering all 308 specimens, the ELISA had a specificity of 93% (when samples with equivocal results were considered negative) or 89% (when samples with equivocal results were considered positive); the sensitivity was 93%.

Hemodialysis: evidence of enhanced molecular clearance and ultrafiltration volume by using pulsatile flow

We describe several in vitro experiments showing evidence that pulsatile flow hemodialysis enhances ultrafiltration volume and molecular clearance as compared with steady flow hemodialysis. A new pulsatile pump and a conventional roller pump were compared using different hollow fiber dialyzers and a simulated blood solution containing urea, aspartame and vitamin B-12 at different flow rates and configurations. Ultrafiltration volume and concentration of urea, aspartame and B-12 were measured and molecular clearance (K) calculated. Ultrafiltration volume markedly increased with pulsatile flow. After 10 min K for urea with pulsatile flow was higher in all experiments even when ultrafiltration was prevented. Clearance of aspartame and B-12 also increased with pulsatile flow. We propose three mechanisms by which pulsatile flow is more efficient than steady flow hemodialysis: greater fluid energy, avoidance of molecular channeling and avoidance of membrane layering. We hypothesize that using pulsatile flow in hemodialysis can significantly shorten the duration of dialysis sessions for most of the patients, and consequently reduce the duration of the procedure and its cost.

Multiple metabolic effects of CGRP in conscious rats: role of glycogen synthase and phosphorylase

Calcitonin gene-related peptide (CGRP) is a neuropeptide that is released at the neuromuscular junction in response to nerve excitation. To examine the relationship between plasma CGRP concentration and intracellular glucose metabolism in conscious rats, we performed insulin (22 pmol.kg-1.min-1) clamp studies combined with the infusion of 0, 20, 50, 100, 200, and 500 pmol.kg-1.min-1 CGRP (plasma concentrations ranging from 2 x 10(-11) to 5 x 10(-9) M). CGRP antagonized insulin's suppression of hepatic glucose production at plasma concentrations (approximately 10(-10) M) that are only two- to fivefold its basal portal concentration. Insulin-mediated glucose disposal was decreased by 20-32% when CGRP was infused at 50 pmol.kg-1.min-1 (plasma concentration 3 x 10(-10) M) or more. The impairment in insulin-stimulated glycogen synthesis in skeletal muscle accounted for all of the CGRP-induced decrease in glucose disposal, while whole body glycolysis was increased despite the reduction in total glucose uptake. The muscle glucose 6-phosphate concentration progressively increased during the CGRP infusions. CGRP inhibited insulin-stimulated glycogen synthase in skeletal muscle with a 50% effective dose of 1.9 +/- 0.36 x 10(-10) M. This effect on glycogen synthase was due to a reduction in enzyme affinity for UDP-glucose, with no changes in the maximal velocity. In vitro CGRP stimulated both hepatic and skeletal muscle adenylate cyclase in a dose-dependent manner. These data suggest that 1) CGRP is a potent antagonist of insulin at the level of muscle glycogen synthesis and hepatic glucose production; 2) inhibition of glycogen synthase is its major biochemical action in skeletal muscle; and 3) these effects are present at concentrations of the peptide that may be in the physiological range for portal vein and skeletal muscle. These data underscore the potential role of CGRP in the physiological modulation of intracellular glucose metabolism.

An unusual case of variegate porphyria with possible homozygous inheritance

We report an unusual case of variegate porphyria in a young girl with epilepsy, mental retardation and premature adrenarche. Symptoms of porphyria commenced about the age of 12 years and death occurred about 18 months later. The patient had very low protoporphyrinogen oxidase activity in her cultured fibroblasts. Both parents had half the normal activity of this enzyme in lymphocytes and are heterozygous for the abnormal gene for variegate porphyria. Therefore, it is possible that the patient was a homozygous variant. Anticonvulsant therapy and low hepatic 5 alpha reductase activity were probably other contributing factors to the severity of the condition in this patient.

Low-loss semiconductor waveguide bends

An experimental comparison is made between the losses of waveguide bends in disorder-delineated waveguides in semiconductor superlattices composed of GaAs and AlAs layers for simple abrupt bends and abrupt bends with an additional half-angle guiding wall proposed by Shiina et al. [Opt. Lett. 11, 736 (1986)]. For light above the band gap of bulk GaAs, the abrupt and Shiina bends were found to have to 3-dB loss angles of 3 and 7 deg, respectively. This improved performance suggests that the specific geometry of the bends is yet another degree of freedom in designing guiding structure for planar routing.

Clinical pharmacological studies with the vasodilator endralazine in patients with renal impairment

The influence of renal impairment on the pharmacokinetics of endralazine was studied in 12 patients; 4 patients on regular haemodialysis therapy (creatinine clearance less than 5 ml/min) and 8 patients with varying degrees of renal impairment (creatinine clearance 11-52 ml/min). Following an oral dose of 10 mg endralazine the mean terminal elimination half-life (beta t1/2) in the dialysis sub-group was prolonged at 7.1 h (range 3.3 to 14 h), compared to 3.6 h in the other renal patients (and compared to 2.3 h in hypertensive patients with normal renal function). After one week's therapy with 10 mg B.D. endralazine in the 8 patients with moderate renal impairment there was a significant increase in beta t1/2 to 8.6 h but there was no significant change in the area under the drug concentration-time curve and no evidence of drug accumulation. In this study those patients with the poorest renal function had the longest beta t1/2 after acute dosing. There was a significant correlation between creatinine clearance and acute beta t1/2 but there was considerable variability in individual patients and, even with severe degrees of renal impairment, major dose adjustments do not appear necessary.

Interaction of bisulfite with unsaturated fatty acids

Sodium bisulfite reacted with unsaturated fatty acids, significantly increasing their polarity as determined by behavior on silica gel thin-layer chromatography. The ultraviolet absorption spectra of unsaturated fatty acids (due to the presence of double bonds) were abolished as a result of the reaction. Fatty acids containing more than one double bond (arachidonate, linolinate, and linoleate) reacted more rapidly with bisulfite than did oleate. When arachidonate double bonds were titrated with bisulfite there was a much larger spectral decrease with the first equivalent of bisulfite added than with each subsequent addition. Vitamin E, vitamin E nicotinate, and butylated hydroxytoluene significantly inhibited the reaction of bisulfite with unsaturated fatty acids. It is suggested that the reaction of bisulfite with unsaturated fatty acids may be a mechanism of SO2 toxicity.