Association of Metformin With the Development of Age-Related Macular Degeneration

Importance

Age-related macular degeneration (AMD) is a leading cause of blindness with no treatment available for early stages. Retrospective studies have shown an association between metformin and reduced risk of AMD.

Objective

To investigate the association between metformin use and age-related macular degeneration (AMD).

Design, Setting, and Participants

The Diabetes Prevention Program Outcomes Study is a cross-sectional follow-up phase of a large multicenter randomized clinical trial, Diabetes Prevention Program (1996-2001), to investigate the association of treatment with metformin or an intensive lifestyle modification vs placebo with preventing the onset of type 2 diabetes in a population at high risk for developing diabetes. Participants with retinal imaging at a follow-up visit 16 years posttrial (2017-2019) were included. Analysis took place between October 2019 and May 2022.

Interventions

Participants were randomly distributed between 3 interventional arms: lifestyle, metformin, and placebo.

Main Outcomes and Measures

Prevalence of AMD in the treatment arms.

Results

Of 1592 participants, 514 (32.3%) were in the lifestyle arm, 549 (34.5%) were in the metformin arm, and 529 (33.2%) were in the placebo arm. All 3 arms were balanced for baseline characteristics including age (mean [SD] age at randomization, 49 [9] years), sex (1128 [71%] male), race and ethnicity (784 [49%] White), smoking habits, body mass index, and education level. AMD was identified in 479 participants (30.1%); 229 (14.4%) had early AMD, 218 (13.7%) had intermediate AMD, and 32 (2.0%) had advanced AMD. There was no significant difference in the presence of AMD between the 3 groups: 152 (29.6%) in the lifestyle arm, 165 (30.2%) in the metformin arm, and 162 (30.7%) in the placebo arm. There was also no difference in the distribution of early, intermediate, and advanced AMD between the intervention groups. Mean duration of metformin use was similar for those with and without AMD (mean [SD], 8.0 [9.3] vs 8.5 [9.3] years; P = .69). In the multivariate models, history of smoking was associated with increased risks of AMD (odds ratio, 1.30; 95% CI, 1.05-1.61; P = .02).

Conclusions and Relevance

These data suggest neither metformin nor lifestyle changes initiated for diabetes prevention were associated with the risk of any AMD, with similar results for AMD severity. Duration of metformin use was also not associated with AMD. This analysis does not address the association of metformin with incidence or progression of AMD.

Florid Foreign Body-type Giant Cell Response to Keratin Is Associated With Improved Overall Survival in Patients Receiving Preoperative Therapy for Esophageal Squamous Cell Carcinoma

While most resection specimens from patients with neoadjuvantly treated esophageal squamous cell carcinoma show therapy-related changes in the form of inflammation and fibrosis, others harbor a florid foreign body-type giant cell response to keratin debris. The purpose of our study was to perform a detailed clinicopathologic analysis of these histologic types of treatment responses and correlate these findings with patient outcome. Clinical and pathologic parameters from 110 esophagogastrectomies were recorded and analyzed. Two main types of histologic responses were observed: inflammatory-predominant response (59%) and florid foreign body-type giant cell response to keratin (41%). Irrespective of cG, cTNM, and amount of residual cancer, florid foreign body-type giant cell reaction was predominantly noted deep within the esophageal wall, while the inflammatory response was restricted to the mucosa, submucosa, and inner half of muscularis propria. Patients with foreign body-type giant cell response showed significantly better overall survival compared with the inflammatory response group (log-rank test P=0.015). Florid foreign body-type giant cell response was the only factor associated with improved survival in a multivariable analysis for overall survival (hazard ratio=0.5; 95% confidence interval=0.3-1.0; P=0.038), but not in the model for disease-specific survival, whereas ypTNM stage II was the only significant risk factor for disease-specific survival in multivariable analysis (hazard ratio=3.4; 95% confidence interval=1.0-11.2; P=0.047). Our results suggest that in addition to the College of American Pathologists Tumor Regression Score and ypTNM stage, subtype of histologic response to therapy may represent another prognostic marker for neoadjuvantly treated esophageal squamous cell carcinoma.

Clinical outcomes for pediatric patients receiving radiotherapy for solid tumor central nervous system metastases

Central nervous system (CNS) metastases are rare, but devastating complications of pediatric solid tumors. Radiotherapy alone or postresection serves as an important treatment; however, data on the use of whole-brain radiotherapy (WBRT) versus focal radiotherapy, including stereotactic radiosurgery or stereotactic radiotherapy, for these indications are limited. We report a single institution experience of 26 pediatric patients treated with radiotherapy for solid tumor CNS metastases without leptomeningeal disease. Focal radiotherapy (n = 10) was well tolerated and survival outcomes did not differ between patients treated with WBRT (n = 16) versus focal radiation, suggesting that focal radiotherapy may be considered for patients with limited CNS metastases.

Music perception and speech intelligibility in noise performance by Italian-speaking cochlear implant users

Objective

The goal of this study was to investigate the performance correlations between music perception and speech intelligibility in noise by Italian-speaking cochlear implant (CI) users.

Materials and methods

Twenty postlingually deafened adults with unilateral CIs (mean age 65 years, range 46–92 years) were tested with a music quality questionnaire using three passages of music from Classical Music, Jazz, and Soul. Speech recognition in noise was assessed using two newly developed adaptive tests in Italian: The Sentence Test with Adaptive Randomized Roving levels (STARR) and Matrix tests.

Results

Median quality ratings for Classical, Jazz and Soul music were 63%, 58% and 58%, respectively. Median SRTs for the STARR and Matrix tests were 14.3 dB and 7.6 dB, respectively. STARR performance was significantly correlated with Classical music ratings (r_s = − 0.49, p = 0.029), whereas Matrix performance was significantly correlated with both Classical (r_s = − 0.48, p = 0.031) and Jazz music ratings (r_s = − 0.56, p = 0.011).

Conclusion

Speech with competitive noise and music are naturally present in everyday listening environments. Recent speech perception tests based on an adaptive paradigm and sentence materials in relation with music quality measures might be representative of everyday performance in CI users. The present data contribute to cross-language studies and suggest that improving music perception in CI users may yield everyday benefit in speech perception in noise and may hence enhance the quality of listening for CI users.

Clinical Characteristics, Experiences, and Outcomes of Transgender Patients With Cancer

Importance

More than 1 million people in the US identify as transgender; however, few studies have examined the experiences and outcomes of transgender patients with cancer.

Objective

To examine clinical characteristics, experiences, and outcomes of transgender patients with cancer.

Design, Setting, and Participants

This retrospective case series assessed transgender patients with at least 1 cancer diagnosis who were evaluated at Dana-Farber Cancer Institute or Brigham and Women's Hospital in Boston, Massachusetts, between January 1, 2005, and December 31, 2019.

Main Outcomes and Measures

Demographic, clinical, and treatment characteristics for all patients and documentation by oncologic practitioners of important aspects of providing gender-affirming care, including pronouns used by the patient, were recorded.

Results

A total of 37 transgender patients with cancer were assessed (mean [SD] age, 38.9 [21.8] years at first cancer diagnosis). Fifteen patients (40.5%) had hematologic malignant cancers, and 25 patients (67.6%) had solid malignant tumors. Sixteen patients (43.2%) initiated gender-affirming hormone therapy or surgery after their cancer diagnosis. Cancer treatment was frequently multimodal, with 24 patients (64.9%) receiving systemic therapy, 24 (64.9%) receiving surgery, and 20 (54.1%) receiving radiation therapy along with other cancer-directed treatment, such as cryoablation. Five patients (13.5%) had documentation from an oncologic practitioner that addressed a potential interaction between their gender-affirming care and their cancer treatment. Thirty-three patients had follow-up visits with oncologic practitioners after starting their transition. Of those patients, pronouns used were documented by a member of the oncologic team for 4 patients (12.1%). However, for 3 of the 4 patients, documentation did not consistently use patient-reported information. At the last follow-up, 5 patients (13.5%) had died of their disease, and 26 (70.3%) were living without disease.

Conclusions and Relevance

This case series study found that transgender patients were diagnosed with diverse cancers, and many initiated gender-affirming hormone therapy or surgery after their diagnosis. Documentation by oncologic practitioners infrequently included pronouns used by the patient or discussion surrounding the interactions between cancer treatment and gender-affirming care, signifying that urgent improvements are needed in cancer care for transgender patients.

Phase I/II Study of Stereotactic Body Radiation Therapy for Pulmonary Metastases in Pediatric Patients

Purpose

Pulmonary metastases are common in many pediatric solid tumors; however, little is known about safety and efficacy of lung stereotactic body radiation therapy (SBRT) for pediatric patients. We conducted a phase I/II study to investigate the minimum effective dose level of SBRT with an acceptable safety profile in pediatric patients.

Methods and Materials

Patients with sarcoma and metastatic pulmonary lesions ≤3 cm in diameter and ≤21 years of age were enrolled. Dose levels 1, 2, and 3 were 24, 30, and 36 Gy in 3 fractions, respectively. Enrolled patients with metastases from primary renal tumors and sarcoma histologies were to begin at dose level 1 and 2, respectively. Exclusion criteria included receipt of whole-lung/hemi-thorax irradiation >12 Gy within 6 months of consent. Primary endpoints were tolerability and safety per Common Terminology Criteria for Adverse Events grading and disease response at 6 weeks post-SBRT per response evaluation criteria in solid tumors (RECIST) 1.1 criteria. Secondary endpoints included rates of local control and distant failure within the lung, but outside of the treatment volume.

Results

Five patients with median age of 13 years (range, 7-21) received SBRT at dose level 2. Primary tumor histologies included Ewing sarcoma (n = 3), anaplastic chordoma (n = 1), and osteosarcoma (n = 1). No grade ≥3 adverse events were observed. At 6 weeks after SBRT, 7/8 (87.5%) lesions achieved partial response. With median follow-up of 2.1 years (range, 1.4-2.5), 2-year local control and distant failure-free survival were 60% (n = 8) and 40% (n = 5), respectively. One patient developed widespread metastases and succumbed to disease 1.4 years after SBRT.

Conclusions

SBRT for pulmonary metastases produces responses in pediatric patients with sarcoma at 6 weeks with acceptable toxicity; however, patients remain at risk of local and distant failure within the lung. Future prospective studies are needed to investigate whether higher doses of SBRT, possibly in combination with other therapies, are safe and provide more durable response.

Use of a healthy volunteer imaging program to optimize clinical implementation of stereotactic MR-guided adaptive radiotherapy

PURPOSE

MR-linacs (MRLs) have enabled the use of stereotactic magnetic resonance (MR) guided online adaptive radiotherapy (SMART) across many cancers. As data emerges to support SMART, uncertainty remains regarding optimal technical parameters, such as optimal patient positioning, immobilization, image quality, and contouring protocols. Prior to clinical implementation of SMART, we conducted a prospective study in healthy volunteers (HVs) to determine optimal technical parameters and to develop and practice a multidisciplinary SMART workflow.

METHODS

HVs 18 years or older were eligible to participate in this IRB-approved study. Using a 0.35 T MRL, simulated adaptive treatments were performed by a multi-disciplinary treatment team in HVs. For each scan, image quality parameters were assessed on a 5-point scale (5 = extremely high, 1 = extremely poor). Adaptive recontouring times were compared between HVs and subsequent clinical cases with a t-test.

RESULTS

18 simulated treatments were performed in HVs on MRL. Mean parameters for visibility of target, visibility of nearby organs, and overall image quality were 4.58, 4.62, and 4.62, respectively (range of 4-5 for all measures). In HVs, mean ART was 15.7 min (range 4-35), comparable to mean of 16.1 (range 7-33) in the clinical cases (p = 0.8963). Using HV cases, optimal simulation and contouring guidelines were developed across a range of disease sites and have since been implemented clinically.

CONCLUSIONS

Prior to clinical implementation of SMART, scans of HVs on an MRL resulted in acceptable image quality and target visibility across a range of organs with similar ARTs to clinical SMART. We continue to utilize HV scans prior to clinical implementation of SMART in new disease sites and to further optimize target tracking and immobilization. Further study is needed to determine the optimal duration of HV scanning prior to clinical implementation.

Palliative radiotherapy for pediatric patients: Parental perceptions of indication, intent, and outcomes

OBJECTIVES

Palliative radiation therapy (pRT) is often used to improve quality of life for pediatric patients. Though palliative doses are generally lower than those for cure, pRT may still introduce undesirable effects. The decision to pursue additional therapy for a child may be challenging and depends on parents' knowledge and expectations. The goal of this study was to explore parental perceptions of pRT.

METHODS

Twenty-eight children referred for pRT were enrolled in our prospective study. Parents were counseled regarding the indication and expected outcomes. They then completed a series of questionnaires to assess their understanding of pRT, side effects that their child experienced, and how the outcomes compared to their expectations.

RESULTS

The majority of parents listed pain relief and addressing new disease as the main indication for pRT. When asked about expectations, the majority chose improvement in quality of life and prolongation of their child's life. Interestingly, 32% of parents expected pRT to cure their child's disease. Most patients undergoing pRT did not experience any adverse symptoms. The outcomes of pRT in the majority of cases exceeded parental expectations.

CONCLUSION

Improved quality of life with pRT sometimes blurs the distinction between palliation and cure. We found that most parents understand the aim to improve quality of life, although a proportion of parents perceived pRT as a cure to their child's disease. Despite this, the majority of parents reported that the outcome of the pRT course exceeded their expectations. We postulate that parents derive comfort from pursuing active treatment.

The rational for a mid-scala electrode array

Today increasing numbers of cochlear implant candidates have residual hearing that can be aided and hence is worth trying to preserve. This means that surgical technique and electrode array design must be adapted to minimize trauma. Wide opening of the round window is often preferred to reduce drill related trauma and to avoid pressure spikes during electrode array insertion. A recent meta-analysis suggested that there is no significant correlation between hearing preservation and either insertion depth or scala position. However, a slow insertion speed of at least 30seconds was associated with better hearing preservation. An electrode design is proposed that targets the middle of the scala tympani. This minimizes frictional forces from either lateral or medial wall during insertion and imposes less static pressure on cochlear structures following insertion. The flexibility to insert via the round window requires a 0.7-mm maximum dimension at the proximal end of the array. Micro-anatomical analysis by micro-CT indicated that a 420-degree insertion depth was optimal between cochlear coverage and available space within the scala tympani. Physical measurements showed that mean insertion forces remained below 10mN during insertion. A series of 20 human temporal bone insertions found a mean insertion depth of 400 degrees with no scala dislocations. Six clinical series, in total 94 cases, found postoperative hearing in 81% of cases with a mean loss of 12dB compared to preoperative levels. Speech understanding out to one year post-fitting trended better for a mid-scala design group than for a straight electrode array group; although the differences were not statistically significant. A mid-scala array design appears able to be inserted with minimal trauma, to return a predictable insertion depth across various sizes of cochleae and to support reasonable levels of speech understanding without relying on residual hearing.

The perception of complex pitch in cochlear implants: A comparison of monopolar and tripolar stimulation

Cochlear implant listeners typically perform poorly in tasks of complex pitch perception (e.g., musical pitch and voice pitch). One explanation is that wide current spread during implant activation creates channel interactions that may interfere with perception of temporal fundamental frequency information contained in the amplitude modulations within channels. Current focusing using a tripolar mode of stimulation has been proposed as a way of reducing channel interactions, minimising spread of excitation and potentially improving place and temporal pitch cues. The present study evaluated the effect of mode in a group of cochlear implant listeners on a pitch ranking task using male and female singing voices separated by either a half or a quarter octave. Results were variable across participants, but on average, pitch ranking was at chance level when the pitches were a quarter octave apart and improved when the difference was a half octave. No advantage was observed for tripolar over monopolar mode at either pitch interval, suggesting that previously published psychophysical advantages for focused modes may not translate into improvements in complex pitch ranking. Evaluation of the spectral centroid of the stimulation pattern, plus a lack of significant difference between male and female voices, suggested that participants may have had difficulty in accessing temporal pitch cues in either mode.

Genome-wide localization of exosome components to active promoters and chromatin insulators in Drosophila

Chromatin insulators are functionally conserved DNA-protein complexes situated throughout the genome that organize independent transcriptional domains. Previous work implicated RNA as an important cofactor in chromatin insulator activity, although the precise mechanisms are not yet understood. Here we identify the exosome, the highly conserved major cellular 3' to 5' RNA degradation machinery, as a physical interactor of CP190-dependent chromatin insulator complexes in Drosophila. Genome-wide profiling of exosome by ChIP-seq in two different embryonic cell lines reveals extensive and specific overlap with the CP190, BEAF-32 and CTCF insulator proteins. Colocalization occurs mainly at promoters but also boundary elements such as Mcp, Fab-8, scs and scs', which overlaps with a promoter. Surprisingly, exosome associates primarily with promoters but not gene bodies of active genes, arguing against simple cotranscriptional recruitment to RNA substrates. Similar to insulator proteins, exosome is also significantly enriched at divergently transcribed promoters. Directed ChIP of exosome in cell lines depleted of insulator proteins shows that CTCF is required specifically for exosome association at Mcp and Fab-8 but not other sites, suggesting that alternate mechanisms must also contribute to exosome chromatin recruitment. Taken together, our results reveal a novel positive relationship between exosome and chromatin insulators throughout the genome.

The Kety-Schmidt technique for quantitative perfusion and oxygen metabolism measurements in the MR imaging environment

SUMMARY

The Kety-Schmidt technique provides quantitative measurement of whole-brain CBF. CBF is measured as the area between the arterial and venous washout curves of a diffusible tracer. Oxygen extraction and metabolism may be calculated from arterial and venous samples. In this report, we present a method for performing these measurements in an MR imaging environment. This technique could be useful for validation of MR imaging methods of hemodynamic and metabolic measurements in humans.

Absence of microorganisms in crustacean digestive tracts

Two marine and one terrestrial wood-boring isopod species and one wood-inhabiting amphipod species maintain a digestive tract free of microorganisms. Digestive tracts examined in toto with the scanning electron microscope were devoid of microorganisms. In contrast, the outer exoskeleton surfaces of these crustaceans support a dense bacterialflora. Observations of the hindgut of termites revealed a diverse gut microflora as expected.

Comparison of dual-time-constant and fast-acting automatic gain control (AGC) systems in cochlear implants

Cochlear implants usually employ an automatic gain control (AGC) system as a first stage of processing. AGC1 was a fast-acting (syllabic) compressor. AGC2 was a dual-time-constant system; it usually performed as a slow-acting compressor, but incorporated an additional fast-acting system to provide protection from sudden increases in sound level. Six experienced cochlear-implant users were tested in a counterbalanced order, receiving one-month of experience with a given AGC type before switching to the other type. Performance was evaluated shortly after provision of a given AGC type and after one-month of experience with that AGC type. Questionnaires, mainly relating to listening in quiet situations, did not reveal significant differences between the two AGC types. However, fixed-level and roving-level tests of sentence identification in noise both revealed significantly better performance for AGC2. It is suggested that the poorer performance for AGC1 occurred because AGC1 introduced cross-modulation between the target speech and background noise, which made perceptual separation of the target and background more difficult.

Comparison of dual-time-constant and fast-acting automatic gain control (AGC) systems in cochlear implants

Cochlear implants usually employ an automatic gain control (AGC) system as a first stage of processing. AGC1 was a fast-acting (syllabic) compressor. AGC2 was a dual-time-constant system; it usually performed as a slow-acting compressor, but incorporated an additional fast-acting system to provide protection from sudden increases in sound level. Six experienced cochlear-implant users were tested in a counterbalanced order, receiving one-month of experience with a given AGC type before switching to the other type. Performance was evaluated shortly after provision of a given AGC type and after one-month of experience with that AGC type. Questionnaires, mainly relating to listening in quiet situations, did not reveal significant differences between the two AGC types. However, fixed-level and roving-level tests of sentence identification in noise both revealed significantly better performance for AGC2. It is suggested that the poorer performance for AGC1 occurred because AGC1 introduced cross-modulation between the target speech and background noise, which made perceptual separation of the target and background more difficult.

A pilot study of the effects of pioglitazone and rosiglitazone on de novo lipogenesis in type 2 diabetes

Treatment of type 2 diabetes mellitus (T2DM) patients with pioglitazone results in a more favorable lipid profile, and perhaps more favorable cardiac outcomes, than treatment with rosiglitazone. Pioglitazone treatment increases VLDL-triacylglycerol clearance, but the role of de novo lipogenesis (DNL) has not been explored, and no direct comparison has been made between the thiazolidinediones (TZDs). Twelve subjects with T2DM and hypertriacylglyceridemia were randomized to either rosiglitazone or pioglitazone treatment. Stable isotope infusion studies were performed at baseline and after 20 weeks of treatment. Both treatments reduced glucose and HbA(1c) concentrations equally. Pioglitazone treatment resulted in a 40% reduction in hepatic DNL (P < 0.01) and in a 25% reduction in hepatic glucose production (P < 0.05), while rosiglitazone did not significantly change either parameter, although comparisons of changes between treatments were not significantly different. These pilot results indicate that pioglitazone reduces hepatic DNL while rosiglitazone does not. Larger follow-up studies are required to confirm differential effects of these agents definitively. The reduction in DNL may underlie altered assembly or atherogenicity of lipoprotein particles and may reflect PPARalpha or other non-PPARgamma actions on the liver by pioglitazone. These differences might help explain previously reported differences in lipid profiles and cardiovascular disease outcomes for rosiglitazone and pioglitazone.

Managing type 2 diabetes: going beyond glycemic control

BACKGROUND

Aggressive management of type 2 diabetes is necessary to achieve glycemic and nonglycemic treatment goals. Attainment of treatment goals is associated with a decreased risk of diabetes-related complications, costs, and health care utilization.

OBJECTIVE

To review the advantages and disadvantages of different glucose-lowering agents, with an emphasis on the role of thiazolidinediones (TZDs).

SUMMARY

Diabetes has become increasingly prevalent, particularly among younger age groups in the United States, accounting for approximately 15% of health care expenditures by managed care organizations. Reducing a patient's glycated hemoglobin (A1C) has been shown to decrease the risk of diabetes-related complications, as well as reduce medical costs and health care utilization. Despite this knowledge, achievement of the American Diabetes Association (ADA) goal A1C of < 7% is suboptimal, and < 1 in 10 patients also reach the ADA targets for cholesterol (low-density lipoprotein < 100 mg per dL) and blood pressure (< 130/80 mm Hg). To ensure that all ADA treatment goals are met, clinicians need to closely monitor patients and adjust therapy as needed, taking into consideration both a drug's glycemic and nonglycemic effects when selecting medication therapy. Four basic defects contribute to type 2 diabetes: insulin resistance, decreased insulin secretion, increased hepatic glucose production, and reduced glucagon-like peptide-1 levels. Unlike metformin, sulfonylureas, and insulin that address only 1 or 2 physiologic defects, TZDs uniquely address 3 of these defects at the adipocyte. Metformin is recommended for initial drug therapy; TZDs, sulfonylureas, and insulin are useful options as add-on therapy for patients whose A1C levels remain >or= 7% despite treatment with metformin and lifestyle interventions. It has been suggested that TZDs, when used either as add-on therapy or when appropriate as monotherapy, may conserve pancreatic beta-cell function over an observed 3- to 5-year period of time and sustain a decrease in A1C ranging from 0.5%-1.5%. Although rarely associated with hypoglycemia, TZDs may cause total body weight gain that is most commonly caused by volume expansion, which may manifest as new or worsened heart failure in susceptible individuals. Pioglitazone and rosiglitazone, the 2 TZDs available in the United States, contain black box label warnings about their potential to cause or exacerbate congestive heart failure; additional data have suggested a link to ischemic cardiac events. Recent data also suggest that TZDs may reduce bone density. Conversely, pioglitazone may have some vasculoprotective effect related to elevation of high-density lipoprotein and lessened progression of carotid intima-media thickness; however, any effect on macrovascular clinical outcomes is unknown. Other drug options are available for the treatment of type 2 diabetes, such as incretin-based therapies. Yet despite their favorable effects on glycemia, they have not been included to date in the ADA treatment algorithm.

CONCLUSIONS

Proper glycemic control and attainment of other nonglycemic management targets (e.g., blood pressure, lipids, body weight) are essential to the prevention of long-term complications of diabetes and to reduction of overall disease management costs. Therefore, patients with diabetes should be followed closely to ensure that they achieve and maintain both glycemic and nonglycemic treatment goals. Most patients will not sustain an adequate level of control using nondrug or single-drug therapeutic approaches. When choosing among treatment options, consideration should be given to the nonglycemic as well as glycemic effects of various glucose-lowering agents.

Impact of therapeutic advances on hypoglycaemia in type 2 diabetes

Patients with type 2 diabetes experience hypoglycaemia less frequently than those with type 1 diabetes. Some protection against hypoglycaemia is afforded by the relatively intact glucose counter-regulatory pathways that characterize the pathophysiology of early type 2 diabetes. To some extent, this protection explains why hypoglycaemic episodes in intensively treated individuals with type 2 diabetes, when they occur, are rarely severe. As diabetes progresses and therapy intensifies to achieve recommended glycaemic goals, hypoglycaemia frequency and severity increase. Thus, when it comes to instituting intensive therapy, fear of hypoglycaemia may contribute to health-care providers' 'clinical inertia'. Because maintaining glycaemic control is so important to both public and individual health, many new therapies and technologies have been developed. This manuscript reviews and considers whether these advancements in therapy make glycaemic goals easier to achieve by minimizing hypoglycaemia. Putting the hypoglycaemia experienced by type 2 diabetes patients into appropriate clinical perspective, the impact of recent progress made in pharmacotherapy, drug delivery systems, and BG monitoring on hypoglycaemia incidence is largely positive. The extent to which this progress can effect improvement over traditional therapies will, however, depend upon patient (and provider) education, motivation and behaviour change.

Immunological evaluation of urinary trypsin inhibitors in blood and urine: role of N- & O-linked glycoproteins

Urinary trypsin inhibitors (uTi) suppress serine proteases during inflammation. After liberation from proinhibitors (P-alpha-I and I-alpha-I) by the white blood cell (WBC) response, uTi readily pass through the kidneys into urine. A key uTi, bikunin, is attached to O-linked and N-linked glycoconjugates. Recently, uTi inhibitors, called uristatins, were found to lack the O-linked glycoconjugates. Monoclonal antibodies were produced using purified uristatin and screened for binding differences to uristatin, bikunin, P-alpha-I, and I-alpha-I. Antibody-binding patterns were characterized using immunoaffinity binding onto protein-chip surfaces and analysis by Surface Enhanced Laser Desorption/Ionization mass spectrometry (SELDI), using specimens from patients and from purified uTi standards. Antibodies were developed and used in an enzyme-linked immunosorbent assay (ELISA) method for uTi measurement in urine and plasma specimens. ELISA was performed on specimens from normal, presumed healthy, controls and from patients who had been screened for inflammation using a high sensitivity C-reactive protein (CRP) test and a complete blood count (CBC). Polyclonal antibody against uTi showed cross-reactivity with the Tamm-Horsfall protein (THP) and with proinhibitors. Screening of anti-uTi monoclonal antibodies (Mab) revealed antibodies that did not cross-react with either of the above, thus providing a tool to measure both uristatin and bikunin in urine with Mab 3G5 and in plasma with Mab 5D11. The monoclonal antibody 5D11 cross-reacts with specific N-linked glycoconjugates of uristatin present in plasma. In ca 96% of healthy adults, uTi were present at <12 mg/l in urine and <4 mg/l in plasma. We also found that patients with an inflammation and a CRP of >2.0 mg/l had higher urinary concentrations of uTi than the control population in every subject. Free uristatin and bikunin pass readily into urine and are primarily bound to heavy chains that constitute the proinhibitor form in plasma.

Diabetes mellitus and macrovascular disease: mechanisms and mediators

Atherosclerosis is a chronic inflammatory condition initiated in the endothelium in response to injury and maintained through the interactions between modified lipoproteins, macrophages, and arterial wall constituents. Risk for macrovascular disease is substantially increased in patients with type 2 diabetes mellitus. Factors underlying the link between insulin resistance/type 2 diabetes and macrovascular disease include reduced adiponectin concentration, increased expression of vascular cell adhesion molecule-1 and consequent adhesion of T-lymphocytes to the coronary endothelium, procoagulability with increased expression of plasminogen activator inhibitor-1 (PAI)-1, and instability of atherosclerotic plaques resulting from increased expression by macrophages of matrix metalloproteinases (MMPs). Thiazolidinediones (TZDs) are agonists of peroxisome proliferator-activated receptor (PPAR)-gamma and increase adiponectin. TZD therapy is associated with decreases in hepatic fat content and glycosylated hemoglobin and an increase in hepatic glucose disposal. TZDs lower circulating free fatty acid concentration and triglyceride content in the liver, but not in skeletal muscle. Effects of PPAR-gamma agonists in vitro and in animal models provide evidence for additional potential antiatherosclerotic benefits in patients with diabetes beyond the treatment of hyperglycemia and dyslipidemia, including the reduction of expression of macrophage MMPs and scavenger receptor-1, and indirect reduction of PAI-1 and inhibition of vascular smooth muscle cell proliferation, via suppression of type 1 angiotensin-2 receptor expression. Dual PPAR-alpha/gamma agonists, retinoid receptor agonists, and, to a lesser extent, TZDs, also stimulate cholesterol efflux from macrophages in vitro.

Identification and analysis of functional elements in 1% of the human genome by the ENCODE pilot project

We report the generation and analysis of functional data from multiple, diverse experiments performed on a targeted 1% of the human genome as part of the pilot phase of the ENCODE Project. These data have been further integrated and augmented by a number of evolutionary and computational analyses. Together, our results advance the collective knowledge about human genome function in several major areas. First, our studies provide convincing evidence that the genome is pervasively transcribed, such that the majority of its bases can be found in primary transcripts, including non-protein-coding transcripts, and those that extensively overlap one another. Second, systematic examination of transcriptional regulation has yielded new understanding about transcription start sites, including their relationship to specific regulatory sequences and features of chromatin accessibility and histone modification. Third, a more sophisticated view of chromatin structure has emerged, including its inter-relationship with DNA replication and transcriptional regulation. Finally, integration of these new sources of information, in particular with respect to mammalian evolution based on inter- and intra-species sequence comparisons, has yielded new mechanistic and evolutionary insights concerning the functional landscape of the human genome. Together, these studies are defining a path for pursuit of a more comprehensive characterization of human genome function.

Application of incretin mimetics and dipeptidyl peptidase IV inhibitors in managing type 2 diabetes mellitus

Approximately two thirds of patients with type 2 diabetes mellitus (T2DM) are unable to reach the hemoglobin A(1c) target set by the American Diabetes Association (HbA(1c) <7.0%). Therefore, T2DM continues to be a major public health concern. Incretin mimetics and dipeptidyl peptidase IV inhibitors are medications that have the potential to improve patients' glycemic control, as well as to result in beneficial socioeconomic effects. Research suggests that significant benefits are to be gained from incretin mimetics and dipeptidyl peptidase IV inhibitors, either one used as monotherapy or used together as combination therapy. However, the benefits and risks of these agents need to be evaluated more thoroughly, with emphasis on such adverse effects as edema, hypoglycemia, and weight gain.

Apoptosis of human breast carcinoma cells in the presence of cis-platin and L-/D-PPMP: IV. Modulation of replication complexes and glycolipid: Glycosyltransferases

Apoptosis of human breast carcinoma cells (SKBR-3, MCF-7, and MDA-468) has been observed after treatment of these cells with anti-cancer drug cis-platin and glycosphingolipid biosynthesis inhibitor L- and D-PPMP, respectively. These drugs initiated apoptosis in a dose-dependent manner as measured by phenotypic morphological changes, by binding of a fluorescent phophatidyl serine-specific dye (PSS-380) onto the outer leaflet of the cell membranes, and by activation of caspases, -3, -8, and -9. It was observed that in two hours very little apoptotic process had started but predominant biochemical changes occurred after 6 h. DNA degradation started after 24 hours of drug treatment. However, very little is known about the stability of the ';Replication Complexes'' during the apoptotic process. DNA helicases are motor proteins that catalyze the melting of genomic DNA during its replication, repair, and recombination processes. Previously, DNA helicase-III was characterized as a component of the replication complexes isolated from embryonic chicken brains as well as breast and colon carcinoma cells. Helicase activities were measured by a novel method (ROME assay), and DNA polymerase-alpha activities were determined by regular chain extension of the nicked ACT-DNA, by determining values obtained from +/- aphidicolin-treated incubation mixtures. In all three breast carcinoma cell lines, a common trend was observed: a decrease of activities of DNA polymerase-alpha and Helicase III. A sharp decrease of activities of the glycolipid sialyltransferases: SAT-2 (CMP-NeuAc; GD3 alpha2-8 sialyltransferase) and SAT-4 (CMP-NeuAc: GM1a alpha2-3 sialyltransferase) was observed in the apoptotic carcinoma cells treated with L-PPMP compared with cis-platin.

Physiological and behavioral aspects of glycemic control and hypoglycemia in diabetes

Homeostatic mechanisms that maintain blood glucose concentration within a narrow physiologic range are complex and redundant. Elaborate feedback loops involving insulin, glucagon, sympathoadrenal mediators, growth hormone, amylin, and incretins normally operate synchronously to keep blood glucose within a narrow set point. Individuals with diabetes have defects in glucose homeostatic pathways, including the counterregulatory pathways that oppose hypoglycemia and ensure sufficient glucose is available to serve the brain's metabolic needs. Because available interventions to manage hyperglycemia do not precisely mimic physiologic insulin secretion patterns, hypoglycemia can occur any time dosing exceeds demand. Focusing on the practical implications, we review the endocrinological principles underlying normal glucose homeostasis and the defects in regulation and counterregulation, including hypoglycemia unawareness, that occur with diabetes. Iatrogenic and behavioral factors that contribute to hypoglycemia risk and nocturnal hypoglycemia are discussed. A companion manuscript reviews the clinical symptoms and fundamentals of hypoglycemia prevention, recognition, and management.

Management of diabetes-related hypoglycemia

Iatrogenic hypoglycemia is the main factor limiting aggressive and optimal diabetes management. Rather than being an inevitable consequence of optimal glycemic control, however, hypoglycemia is avoidable and generally straightforward to manage when it occurs. Professional caregivers, patients, and their families are often fearful of hypoglycemia, even though most episodes are minor and easily self-treated. Understanding the factors contributing to hypoglycemia risk and how to minimize its occurrence is an essential part of diabetes care. Building on the physiologic fundamentals presented in the accompanying review, the incidence, mortality/morbidity, clinical symptoms, severity classification, and psychosocial impact of hypoglycemia are described here. Appropriate selection and titration of therapeutic agents, including insulin analogs with more predictable time-action profiles than human insulin formulations, can reduce hypoglycemia risk. Patient education about hypoglycemia prevention, including symptom recognition and necessity of rapid treatment, behavioral modification, and the importance of frequent blood glucose monitoring should accompany all therapeutic interventions.

Smoking compromises cause-specific survival in patients with operable colorectal cancer

AIMS

To assess whether active smoking compromises survival in patients with colorectal cancer.

MATERIALS AND METHODS

We studied a regionally based cohort of 284 consecutive patients referred to the Tayside Cancer Centre for consideration of adjuvant treatment after curative surgery for colorectal cancer.

RESULTS

Cause-specific survival was significantly worse (P = 0.0015) in patients who were actively smoking at the time of their first post-operative visit. The absolute difference in 5-year cause-specific survival (active smokers vs the rest) was 21%. In adjusted multi-variate analysis of patients after pathologically complete (R0) resection, the hazard ratio was 2.55 (95% confidence interval 1.40-4.64) in active smokers compared with non-smokers. T stage, number of positive nodes and co-morbidity score were also of independent prognostic influence.

CONCLUSIONS

Persistent smoking was, in this small series, an important and independent predictor of cancer-related death after surgery for cancer of the large bowel. Because smoking and deprivation are related, some of the adverse effects of deprivation upon survival in this group of patients may be explained by smoking behaviour.

Brain oxygen utilization is unchanged by hypoglycemia in normal humans: lactate, alanine, and leucine uptake are not sufficient to offset energy deficit

During hypoglycemia, substrates other than glucose have been suggested to serve as alternate neural fuels. We evaluated brain uptake of endogenously produced lactate, alanine, and leucine at euglycemia and during insulin-induced hypoglycemia in 17 normal subjects. Cross-brain arteriovenous differences for plasma glucose, lactate, alanine, leucine, and oxygen content were quantitated. Cerebral blood flow (CBF) was measured by Fick methodology using N(2)O as the dilution indicator gas. Substrate uptake was measured as the product of CBF and the arteriovenous concentration difference. As arterial glucose concentration fell, cerebral oxygen utilization and CBF remained unchanged. Brain glucose uptake (BGU) decreased from 36.3+/-2.6 to 26.6+/-2.1 micromol.100 g of brain(-1).min(-1) (P<0.001), equivalent to a drop in ATP of 291 micromol.100 g(-1).min(-1). Arterial lactate rose (P<0.001), whereas arterial alanine and leucine fell (P<0.009 and P<0.001, respectively). Brain lactate uptake (BLU) increased from a net release of -1.8+/- 0.6 to a net uptake of 2.5+/-1.2 micromol.100 g(-1).min(-1) (P<0.001), equivalent to an increase in ATP of 74 micromol.100 g(-1).min(-1). Brain leucine uptake decreased from 7.1+/-1.2 to 2.5 +/- 0.5 micromol.100 g(-1).min(-1) (P<0.001), and brain alanine uptake trended downward (P<0.08). We conclude that the ATP generated from the physiological increase in BLU during hypoglycemia accounts for no more than 25% of the brain glucose energy deficit.

Nano-biosensor development for bacterial detection during human kidney infection: use of glycoconjugate-specific antibody-bound gold NanoWire arrays (GNWA)

Infectious disease, commonly caused by bacterial pathogens, is now the world's leading cause of premature death and third overall cause behind cardiovascular disease and cancer. Urinary Tract Infection (UTI), caused by E. coli bacteria, is a very common bacterial infection, a majority in women (85%) and may result in severe kidney failure if not detected quickly. Among hundreds of strains the bacteria, E. coli 0157:H7, is emerging as the most aggressive one because of its capability to produce a toxin causing hemolytic uremic syndrome (HUS) resulting in death, especially in children. In the present study, a project has been undertaken for developing a rapid method for UTI detection in very low bacteria concentration, applying current knowledge of nano-technology. Experiments have been designed for the development of biosensors using nano-fabricated structures coated with elements such as gold that have affinity for biomolecules. A biosensor is a device in which a biological sensing element is either intimately connected to or integrated within a transducer. The basic principle for the detection procedure of the infection is partly based on the enzyme-linked immunosorbent assay system. Anti-E. coli antibody-bound Gold Nanowire Arrays (GNWA) prepared on anodized porous alumina template is used for the primary step followed by binding of the bacteria containing specimen. An alkaline phosphatase-conjugated second antibody is then added to the system and the resultant binding determined by both electrochemical and optical measurements. Various kinds of GNWA templates were used in order to determine the one with the best affinity for antibody binding. In addition, an efficient method for enhanced antibody binding has been developed with the covalent immobilization of an organic linker Dithiobissuccinimidylundecanoate (DSU) on the GNWA surface. Studies have also been conducted to optimize the antibody-binding conditions to the linker-attached GNWA surfaces for their ability to detect bacteria in clinical concentrations.

Apoptosis of human carcinoma cells in the presence of potential anti-cancer drugs: III. Treatment of Colo-205 and SKBR3 cells with: cis -platin, Tamoxifen, Melphalan, Betulinic acid, L-PDMP, L-PPMP, and GD3 ganglioside

Breast cancer is the most common type of cancer, predominantly among women over 20, whereas colo-rectal cancer occurs in both men and women over the age of 50. Chemotherapy of both cancers affect rapidly growing normal as well as cancer cells. Cancer cells are non-apoptotic. Seven anti-cancer agents (cis -platin, Tamoxifen, Melphalan, Betulinic acid, D-PDMP, L-PPMP, and GD3) have been tested with human breast (SKBR3) and colon (Colo-205) carcinoma cells for their apoptotic effect and found to be positive by several assay systems. Colo-205 cells were obtained from ATCC, and the SKBR3 cells were a gift from the Cleveland Clinic. All of these six agents killed those two cell lines in a dose-dependent manner. In the early apoptotic stage (6 h), these cells showed only a flopping of phosphatidylserine on the outer lamella of the plasma membranes as evidenced by the binding of a novel fluorescent dye PSS-380. After 24 h of the treatment, those apoptotic cells showed damage of the plasma as well as the nuclear membrane as evidenced by binding of propidium iodide to the nuclear DNA. DNA laddering assay viewed further breakdown of DNA by 1% agarose gel electrophoresis analysis. It is concluded that during apoptosis the signaling by Mitochondrial Signaling Pathway (MSP) is stimulated by some of these agents. Caspase 3 was activated with the concomitant appearance of its p17 polypeptide as viewed by Westernblot analyses. Incorporation of radioactivity from [U-(14)C]-L-serine in total sphingolipid mixture was observed between 2 and 4 micromolar concentrations of most of the agents except ci s-platin. However, apoptosis in carcinoma cells in the presence of cis -platin is induced by a caspase 3 activation pathway without any increase in synthesis of ceramide.

What are the effects of peroxisome proliferator-activated receptor agonists on adiponectin, tumor necrosis factor-alpha, and other cytokines in insulin resistance?

Patients with type 2 diabetes are at high risk of cardiovascular disease. In addition to treating hyperglycemia, the thiazolidinedione (TZD) class of antidiabetic agents may also benefit the cardiovascular complications associated with the disease. The two available TZDs, pioglitazone and rosiglitazone, are peroxisome proliferator-activated receptor-gamma (PPAR-gamma) agonists that influence gene expression of key proteins involved in regulating glucose and lipid metabolism. Tumor necrosis factor-alpha (TNF-alpha) and adiponectin are believed to be important in the development of insulin resistance and atherosclerosis. Understanding the role of these cytokines in the inflammatory processes that trigger plaque development might lead to identification of other potential mechanisms that could be exploited to enhance future treatments for patients with diabetes and atherosclerosis.

Impact of adjunctive thiazolidinedione therapy on blood lipid levels and glycemic control in patients with type 2 diabetes

OBJECTIVE

This study was undertaken to assess the effect of pioglitazone hydrochloride and rosiglitazone maleate on blood lipid levels and glycemic control when these drugs are used as adjunctive therapy in type 2 diabetes.

RESEARCH DESIGN AND METHODS

Patients with type 2 diabetes receiving metformin and/or sulfonylurea (n = 829) were evaluated in this national, multicenter, retrospective study. Medical records from 318 endocrinology practices in the USA were randomly selected and screened for study inclusion. Data related to patient demographics and laboratory data were extracted from medical records and analyzed for primary and secondary outcomes.

MAIN OUTCOME MEASURES

The primary study outcome was the mean change in plasma rosiglitazone was associated with no significant triglyceride (TG) levels. Secondary outcome measures included mean changes in total cholesterol (TChol), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) concentrations and hemoglobin A1C levels.

RESULTS

With pioglitazone, TG levels declined by a mean of 51.5 mg/dl (P < 0.001), HDL-C levels rose by 3.3mg/dl (P < 0.001), and no change was seen in LDL-C or TChol. Treatment with change in TG levels and a 1.5mg/dl mean increase in HDL-C (P < 0.001). Furthermore, rosiglitazone therapy was associated with an 8 mg/dl mean increase in TChol (P < 0.001), and a 5.8 mg/dl mean increase in LDL-C (P < 0.001). Hemoglobin A1C levels were significantly reduced by approximately 1% within thiazolidinedione (TZD) cohorts (P < 0.001), but were not significantly different between study groups (P = 0.257).

CONCLUSIONS

Results from this study suggest that pioglitazone has a more favorable effect on lipid profiles of patients with type 2 diabetes compared with rosiglitazone. In particular, differences were observed in TG and LDL-C levels. Both TZDs were equivalent at reducing hemoglobin A1C levels. These differences in lipid effects may have an impact on cardiovascular outcomes. The full clinical importance of these lipid alterations must be further assessed in prospective trials.

Spatial clustering of amyotrophic lateral sclerosis in Finland at place of birth and place of death

Previous evidence for spatial clustering of amyotrophic lateral sclerosis is inconclusive. Studies that have identified apparent clusters have often been based on a small number of cases, which means the results may have occurred by chance processes. Also, most studies have used the geographic location at the time of death as the basis for cluster detection, rather than exploring clusters at other points in the life cycle. In this study, the authors examine 1,000 cases of amyotrophic lateral sclerosis distributed throughout Finland who died between June 1985 and December 1995. Using a spatial-scan statistic, the authors examine whether there are significant clusters of the disease at both time of birth and time of death. Two significant, neighboring clusters were identified in southeast and south-central Finland at the time of death. A single significant cluster was identified in southeast Finland at the time of birth, closely matching one of the clusters identified at the time of death. These results are based on a large sample of cases, and they provide convincing evidence of spatial clustering of this condition. The results demonstrate also that, if the cluster analysis is conducted at different stages of the cases' life cycle, different conclusions about where potential risk factors may exist might result.

The Clarion Electrode positioner: approximation to the medial wall and current focussing?

In order to establish whether the electrical field created by a cochlear implant electrode is more focussed in a perimodiolar than in a medial position, voltages at non-stimulated electrodes were collected from the Clarion 1.2 implant before and after insertion of the Clarion Electrode Positioning System. The positioner is inserted lateral to the electrode array and is intended to bring the array close to the medial wall of the scala tympani. These intracochlear electrode voltages (IEVs) were collected in 9 surgeries with the HiFocus I electrode array with positioner. Stapedius reflex thresholds were decreased after insertion of the positioner on 20 out of 22 electrodes. Electrode impedances did not increase significantly. IEVs increased slightly for all stimulated electrodes. However, the positioner did not significantly affect the slope of the IEVs for any of the stimulated electrodes. Individual differences between patients in the mean IEV amplitude were considerable; 2 patients deafened by otosclerosis showed particularly low amplitudes. Thus, IEVs provided no evidence of a focussing of the electrical field by introducing the positioner. Possible benefits of a perimodiolar position regarding efficiency and channel separation are discussed in terms of a reduced distance between electrodes and neural elements.

Effects of pioglitazone and rosiglitazone on blood lipid levels and glycemic control in patients with type 2 diabetes mellitus: a retrospective review of randomly selected medical records

BACKGROUND

The antihyperglycemic effects of pioglitazone hydrochloride and rosiglitazone maleate are well documented. The results of clinical trials and observational studies have suggested, however, that there are individual differences in the effects of these drugs on blood lipid levels.

OBJECTIVE

The present study evaluated the effects of pioglitazone and rosiglitazone on blood lipid levels and glycemic control in patients with type 2 diabetes mellitus.

METHODS

This was a retrospective review of randomly selected medical records from 605 primary care practices in the United States in which adults with type 2 diabetes received pioglitazone or rosiglitazone between August 1, 1999, and August 31, 2000. The outcome measures were mean changes in serum concentrations of triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and glycosylated hemoglobin (HbA1c) values.

RESULTS

Treatment with pioglitazone was associated with a reduction in mean TG of 55.17 mg/dL, a reduction in TC of 8.45 mg/dL, an increase in HDL-C of 2.65 mg/dL, and a reduction in LDL-C of 5.05 mg/dL. Treatment with rosiglitazone was associated with a reduction in mean TG of 13.34 mg/dL, an increase in TC of 4.81 mg/dL, a reduction in HDL-C of 0.12 mg/dL, and an increase in LDL-C of 3.56 mg/dL. With the exception of HDL-C, the differences in mean changes in lipid parameters between treatment groups were statistically significant (P < 0.001, pioglitazone vs rosiglitazone). Reductions in HbA1c were statistically equivalent between treatments (1.04% pioglitazone, 1.18% rosiglitazone).

CONCLUSIONS

Treatment with pioglitazone was associated with greater beneficial effects on blood lipid levels than treatment with rosiglitazone, whereas glycemic control was equivalent between the 2 treatments.

Do area-level population change, deprivation and variations in deprivation affect individual-level self-reported limiting long-term illness?

A previous study showed that variations in deprivation within small localities in England and Wales influenced the rates of self-reported limiting long-term illness, controlling for overall levels of deprivation. These results suggest that while morbidity is related to overall levels of material deprivation, the distribution of resources within small areas have a significant effect on health outcomes. However, it is possible that these area effects become redundant once individual-level characteristics are accounted for. This analysis examines whether area-level deprivation and variations in deprivation are significant indicators of individual-level limiting long-term illness, once individual characteristics have been accounted for.

Hypoglycemia. Pathophysiology and treatment

Hypoglycemia is a common consequence of many diabetes treatments. As is true for many therapies for diseases with major pathologic consequences, the benefits and risks of treatment must be balanced. In intensified diabetes management, hypoglycemia is not an insurmountable problem but is unfortunately inevitable using the methods of glucose control currently available. Patients with type 1 diabetes seem to be at greater risk than patients with type 2 disease. The health care team must strive to help the patient maintain normoglycemia. The results of the DCCT and the United Kingdom Prospective Diabetes Study prove that near normoglycemia is clearly in the patient's best interest. Patient education has become focused on minimizing hyperglycemia; counseling on the dangers of hypoglycemia has not been given the same stature. Emphasis must be placed on minimizing even minor subclinical hypoglycemia because it will contribute to a vicious cycle of hypoglycemia begetting hypoglycemia.